US20090213283A1 - Apparatus and method for adjustable variable transmissivity polarized eye glasses - Google Patents
Apparatus and method for adjustable variable transmissivity polarized eye glasses Download PDFInfo
- Publication number
- US20090213283A1 US20090213283A1 US12/072,535 US7253508A US2009213283A1 US 20090213283 A1 US20090213283 A1 US 20090213283A1 US 7253508 A US7253508 A US 7253508A US 2009213283 A1 US2009213283 A1 US 2009213283A1
- Authority
- US
- United States
- Prior art keywords
- light
- lens
- transmissivity
- lenses
- avt
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
- G02C7/00—Optical parts
- G02C7/10—Filters, e.g. for facilitating adaptation of the eyes to the dark; Sunglasses
- G02C7/101—Filters, e.g. for facilitating adaptation of the eyes to the dark; Sunglasses having an electro-optical light valve
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/13306—Circuit arrangements or driving methods for the control of single liquid crystal cells
- G02F1/13318—Circuits comprising a photodetector
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/1313—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells specially adapted for a particular application
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/133308—Support structures for LCD panels, e.g. frames or bezels
Definitions
- the present invention relates generally to the field of treatment for age related macular degeneration. More specifically, the invention is a set of eye glasses which electronically dim and brighten according to ambient light conditions.
- Ophthalmologists have long sought a prescriptive solution wherein the ARMD patient may be fit with light absorbing eye glasses that restrict the amount of light reaching the patient's eyes thereby increasing visual acuity.
- the eye glasses must adapt to a wide range of lighting conditions ranging from the office environment wherein light luminance levels are typically on the order of 12-18 cd/m 2 to a bright sunny day outside, wherein luminance levels may be on the order of 5000 cd/m 2 .
- the need for light absorbing eye glasses with a wide dynamic range thus exists.
- the eye glasses must respond quickly to keep the retinal illumination level near an ideal value so that dark adaptation effects are not impaired and retinal bleaching does not occur.
- contrast sensitivity polarization arrangements yielding a yellow lens color is advantageous to achieving the greatest contrast sensitivity.
- One major flaw is the inability of the ophthalmologist to adjust for the patient to patient variation of dark to bright transmission ranges, and for the patient's overall illumination response.
- the present invention allows for such control by the ophthalmologist.
- control group studies of subject response to light absorbing eye glasses were made according to Ross and Mancil in “Design and Evaluation of Liquid Crystal (LC) Dark Adapting Eye Glasses for Persons with Low Vision”, Final Report, Project #C776-RA, Atlanta V.A. Rehab Center, March 1997, indicating that subjects preferred to maintain some control over the lens behavior of the light absorbing eye glasses.
- the present invention allows for limited patient manual override through the use of controls on the ear pieces, one control setting the low light level characteristic of the lens function and the other control setting the upper light level limiting characteristic of the lens function.
- AVT eyewear is useful in the treatment of retinal pigmentosa, ocular albinism, choroidermia, gyrate atrophy, corneal scarring, cataracts and ureitis.
- a variety of outdoor sporting activities including fishing, hunting, skiing, golf and baseball may benefit from the present invention.
- Occupational safety applications are conceived for driving, heavy equipment operation, low light military or police maneuvers, oxyacetylene welding and glassblowing.
- AVT eye glasses comprise a set of frames and a pair of lenses attached to the frames, the set of lenses being made of liquid crystal substrates that change their transmittance upon application of an electric potential.
- the frames are made to fit a wearer's face over prescription eyewear and to house electronics circuits and batteries for controlling the function of the lenses. Additionally, the frames allow for a light pipe connected to a light sensor to detect ambient light from the direction forward of the wearer with variable field of viewing using light pipe plugs to restrict the angle of view as well as the overall field of view.
- the frames have earpieces attached to which the electronics substrates may be housed and to which a left control and a right control are fixed, the left and right controls electronically connected to electronics circuits contained on the electronics substrates.
- the light pipe is configured to detect transmitted light through the lens to maintain a constant light level to the wearer's eye.
- the electronics substrate may be housed in the frames instead of the earpieces.
- the liquid crystal lens is comprised of two substrates fixed together and having a liquid crystal material between them.
- the substrates are further comprised of an Indium Tin Oxide (ITO) coated glass substrate with a polarizing film on one side and an alignment layer on the other side.
- ITO Indium Tin Oxide
- a fail dark configuration of the alignment and polarizing layers is taught wherein the polarizers are set vertical and the alignment layers are set at ⁇ 45 degrees and +45 degrees from the horizontal.
- the fail dark lens configuration causes the lens transmittance to go to a low value when power is removed from the lenses.
- a fail light configuration is taught wherein the polarizers are set at a 90 degree angle from each other, one being in the vertical and the second being in the horizontal, the alignment layers being at ⁇ 45 degrees and +45 degrees to the horizontal, respectively.
- the fail light lens configuration causes the lens transmittance to go to a high value when power is removed from the lenses.
- Typical fail dark transmittance is 6% and typical fail light transmittance is
- Electronic circuits are taught to accomplish the lens control under different conditions. In the condition wherein ambient light is sensed, an analog electronics circuit and a digital electronics circuit is taught, the latter including the use of a microprocessor. An analog feedback control circuit is taught for the situation when transmitted light is sensed and it is desired to fix the transmitted light level at a given value. Electronics circuits in the preferred embodiment of the present invention utilize a variable duty cycle of alternating current square wave signal to affect control of the lens average voltage and thereby the lens transmissivity.
- the desired transmissivity curve is the Weber-Fechner logarithmic response. In other embodiments linear response or other response curves may be utilized in the present invention.
- a software program for controlling the function of variable transmissivity eye glasses is explained taking into account the automatic light level adjustment according to a desired transmissivity curve and taking into account the use of controls.
- FIG. 1A is a frontal view of a first embodiment AVT eye glasses showing the lens and frames.
- FIG. 1B is a top view of a first embodiment AVT eye glasses showing the frames and earpieces.
- FIG. 1C is a side view of a first embodiment AVT eye glasses while partially folded.
- FIGS. 1D and 1E are right and left side views, respectively, of a first embodiment AVT eye glasses while unfolded.
- FIG. 2A is a cross-sectional view of a light plug situated in the AVT eyeglasses frame.
- FIG. 2B is a perspective view of a light plug.
- FIG. 2C is a frontal view of the light plug situated in the eyeglasses frame.
- FIG. 2D is a cross-sectional view of a light pipe plug situated in the AVT eye glasses frame.
- FIG. 2E is a perspective view of a light pipe plug.
- FIG. 3A is a frontal view of the of second embodiment AVT eye glasses showing the frames and light sensor position behind the lens.
- FIG. 3B is a top view of the of second embodiment AVT eye glasses showing the frames and light sensor position behind the lens.
- FIG. 3C is a side view of the second embodiment AVT eye glasses.
- FIG. 3D is a cross-sectional view of a light pipe plug situated behind the AVT eye glasses lens.
- FIG. 4 is a geometric drawing of the lens structure in the preferred embodiment of the present invention.
- FIG. 5A is a front perspective drawing of the inner and outer lens substrates with top down view looking towards the front face of the lenses, the drawing pertaining to the fail dark lens substrate arrangement.
- FIG. 5B is a front perspective drawing of the inner and outer lens substrates with top down view looking towards the front face of the lenses, the drawing pertaining to the fail light lens substrate arrangement.
- FIG. 6 is a block diagram of the electronic circuitry for the AVT glasses with direct ambient photosensing.
- FIG. 7 is a block diagram of the electronic circuitry for the AVT glasses with photosensing from behind the lens.
- FIG. 8 is a block diagram of the electronic circuitry for the AVT glasses with direct ambient photosensing and using a microprocessor for control in the preferred embodiment.
- FIG. 9 is a graph of AVT glasses transmittance curves showing the preferred embodiment transmissivity curve.
- FIG. 10 is a graph showing the LCD response curve of transmissivity versus duty cycle in the preferred embodiment of the present invention, curves for fail dark and fail light modes are shown.
- FIG. 11 is pseudocode listing of the modulation software used by the microprocessor to control the function of the eyeglasses and the lenses.
- FIG. 12A is block diagram of an apparatus to calibrate the light sensor of the eyeglasses.
- FIG. 12B is a block diagram of an apparatus to calibrate the transmissivity of the eye glass lenses.
- FIG. 13 is a flow chart of a preferred method to calibrate the AVT eyeglasses.
- FIG. 14 is a flow chart of a physician's program.
- FIG. 15 is a graphical depiction of the display page of the physician's program.
- FIG. 16 is a graph of a typical light sensor response.
- FIG. 17 is a graph of a typical light sensor spectral response.
- the numerous innovative teachings of the present application will be described with particular reference to the presently preferred embodiments (by way of example, and not of limitation).
- the present invention teaches an apparatus and corresponding methodology for making and using adjustable variable transmissivity (AVT) eyeglasses.
- APT adjustable variable transmissivity
- FIGS. 1D and 1E side views of normally opened AVT eyeglasses 10 show that an electronics circuit 33 is integrated into earpiece 20 , electronics circuit 33 being electrically attached to light sensor 32 and to batteries 22 contained in battery compartment 21 .
- Ear piece 18 also has left control 36 ;
- ear piece 20 also has right control 37 , the controls used in the preferred embodiment to set the lower and upper light level limits for electronic control of the duty cycle for maximum and minimum transmission of the light through the lens.
- An on/off switch may be incorporated into ear pieces 18 and 20 near hinges 8 and 9 , respectively, such that the switch is turned on when the ear pieces are unfolded for wearing, supplying voltage from the battery to electronics circuit 33 .
- the controls 36 and 37 are a button type switch in a preferred embodiment. In an alternate embodiment, controls 36 and 37 may be rotatable screws connected to a potentiometer. Other embodiments include slide switches or other rotating switches as known in the art.
- controls 36 and 37 and the on/off switch may be accomplished in a variety of ways in other embodiments consistent with the present invention.
- controls 36 and 37 may be incorporated into the ear pieces in another embodiment.
- controls 36 and 37 may constructed to make patient control more difficult so that settings are managed by a physician.
- a vertical offset distance 31 causes a vertical shift of the field of view while a horizontal offset distance 31 causes a horizontal shift of the field of view.
- the horizontal plane is defined as the plane containing the center point of both lenses.
- the vertical plane is a plane perpendicular to the horizontal plane for which all points are equidistant from the center point of both lenses.
- Input aperture 58 a and output aperture 58 b may be formed by depositing metal on surfaces 61 a and 61 b and etching the deposited metal to create transparent areas on both surfaces.
- Output aperture 58 b may have its center offset from the center of input aperture 58 a , the offset being in the vertical or horizontal direction by an offset distance (not shown).
- offset distance (not shown).
- light pipes with different fields of view and different offset distances may be inserted into bridge area 26 as required for the wearer.
- FIGS. 3A , 3 B, 3 C show a second embodiment of AVT eyeglasses 11 of the present invention.
- FIG. 3A is a frontal view of AVT eyeglasses 11 which includes lens 12 and lens 14 mounted in frame 16 , lens 12 and lens 14 have electronically controllable optical density as in the first embodiment.
- Sensor element 40 is contained in the bridge area 26 of frame 16 and has a light sensor 42 .
- Light sensor 42 is positioned behind lens 12 so that it senses light that is transmitted through lens 12 .
- AVT eyeglasses 11 also have earpieces, an electronics circuit, controls and a battery compartment similar to those described for AVT eyeglasses 10 .
- FIGS. 4 , 5 A and 5 B show the structure of LCD lens 100 of the present invention.
- lens 100 corresponds to lens 12 and lens 14 of FIGS. 1-3 .
- Lens 100 is comprised of a twisted nematic liquid crystal material 110 sandwiched between an inner substrate 101 nearest the wearer's eye 103 and an outer substrate 102 nearest the object or light source 105 .
- the incident light has direction vector 117 and the transmitted light has direction vector 109 .
- the outer substrate 102 is comprised of several layers and components.
- an electric potential is applied between the first conducting ITO glass substrate 106 and the second conducting ITO glass substrate 114 to affect the orientation of the liquid crystal and thereby change the transmissivity of the lens 100 .
- the applied electric potential is an alternating potential.
- FIG. 5A shows a fail dark embodiment of the lens 100 so that when the electric potential is zero between inner substrate 101 and outer substrate 102 , the lens 100 has a low transmissivity.
- the FIG. 5A is drawn so that the surfaces while looking down at the page are the front facing surfaces of the two lens substrates looking towards the wearer's eye; a further description being that the transmitted light vector 109 is going into the page in FIG. 5A .
- the fail dark transmissivity value is approximately 6%. In other embodiments the fail dark transmissivity may achieve a lower value.
- the polarizer of outer substrate 102 is arranged to transmit linear polarization in first direction 131 and alignment layer scribed in second direction 132 , the first direction 131 being vertical and the second direction 132 being at an angle of 45 degrees clockwise from horizontal. Furthermore, the polarizer of inner substrate 101 is arranged to transmit linear polarization in third direction 133 and alignment layer scribed in fourth direction 134 , the third direction 133 being vertical and the fourth direction 134 being 45 degrees counterclockwise from horizontal.
- FIG. 5B shows a fail light embodiment of the lens 100 wherein when the electric potential is zero between inner substrate 101 and outer substrate 102 , the lens 100 has a high transmissivity.
- FIG. 5B is drawn similar to FIG. 5A so that the transmitted light vector 109 is going into the page.
- the fail light transmissivity value is approximately 30%. In other embodiments, the fail light transmissivity may be higher.
- the polarizer of outer substrate 102 is arranged to transmit linear polarization in fifth direction 151 and alignment layer scribed in sixth direction 152 , the fifth direction 151 being vertical and the sixth direction 152 being 45 degrees clockwise from the horizontal direction.
- the polarizer of inner substrate 101 is arranged to transmit linear polarization in seventh direction 153 and alignment layer scribed in eighth direction 154 , the seventh direction 153 being horizontal and the eight direction 154 being 45 degrees counterclockwise from the horizontal direction.
- FIG. 6 is a block diagram of a first embodiment electronic circuit 200 .
- Electronic circuit 200 provides electronic control of the transmissivity of lens element 218 allowing for a certain fraction of incident light 201 to fall on a wearer's eye 219 and is comprised of a dc/dc boost converter 221 connected to a battery 220 ; a light sensor 202 ; an amplifier 204 connected to light sensor 202 , the amplifier 204 having gain control 205 and bias control 206 ; a pulse width modulator 210 connected to amplifier 204 ; an oscillator 211 driving the frequency and timing of the pulse width modulator 210 ; a buffer amplifier 214 connected to lens element 218 for conditioning a drive signal 216 to drive lens element 218 , the input of buffer amplifier 214 connected to pulse width modulator 210 and generating PWM signal 212 .
- Electronic circuit 240 further comprises a comparator 247 with voltage reference 253 ; a charging circuit 250 connected to capacitor 251 for charging a capacitor 251 having peak voltage reference 248 , a voltage follower 254 connected to capacitor 251 and charging circuit 250 ; a pulse width modulator circuit 256 connected to the output of voltage follower 254 and driven by an oscillator 255 , and a buffer amplifier 258 connected to PWM circuit 256 and to lens element 242 for driving lens element 242 .
- PWM circuit 256 produces a PWM signal 259 of variable duty cycle and fixed period, the period being determined by oscillator 255 .
- Photovoltage signal 235 is connected to the input of comparator 247 which enables charging signal 237 a or discharging signal 237 b depending upon a comparison between the photovoltage signal 235 and the reference voltage 253 . If the photovoltage signal is less than the reference voltage, then the charge signal 237 a is enabled and charging circuit 250 allows capacitor 251 to be charged to a capacitor voltage 252 determined by peak voltage reference 248 . If the photovoltage signal is greater than the reference voltage, then the discharge signal 237 b is enabled and charging circuit 250 discharges capacitor 251 causing the capacitor voltage 252 to go to ground. If the photovoltage signal is approximately the same as the reference voltage, then neither of signals 237 a or 237 b are enabled and the capacitor voltage 252 is not altered except for circuit leakages.
- a voltage follower 254 creates current buffered PWM input voltage 238 proportional to capacitor voltage 252 , PWM input voltage 238 determining the duty cycle of PWM signal 259 .
- PWM circuit 256 is connected to buffer amplifier 258 , which in turn drives the lens element.
- PWM circuit 256 may be a 555 timer chip operating in PWM mode as known in the art, with PWM input voltage 238 driving the 555 timer's control voltage input. The duty cycle varies from about 5% to about 50%.
- Electronic circuit 260 also has a charge pump circuit 279 for generating an alternating current drive signal and further contains an AND gate 284 with one input being square wave signal 287 and a second input being GATE line 272 which is connected to and driven by microprocessor 268 .
- the output of AND gate 284 is PWM signal 273 which is connected to charge pump circuit 279 .
- the AND gate may be synthesized in the program logic contained in program instructions and the GATE line 272 becomes equivalent to PWM signal 273 .
- incident light 262 falls on light sensor 261 wherein the detected light quanta are converted to photocurrent and then to a photovoltage proportional thereto.
- the photovoltage is read by A/D converter 264 in conjunction with microprocessor 268 to determine a measured incident light luminance which is used according to program instructions 285 to drive GATE line 272 which sets the duty cycle of PWM signal 273 .
- microprocessor 268 has stored in memory 269 parameters 286 including at least an upper transmissivity limit, T_max, a lower transmissivity limit, T_min, and incident light levels L 1 and L 2 , associated to the transmissivity limits.
- T_min and T_max are predetermined so that electronic circuit 260 is calibrated during manufacture to produce T_min at about 50% PWM signal duty cycle and T_max at about 5% duty cycle.
- T_max is typically 29% transmissivity and T_min is typically 6% transmissivity.
- Program instructions 285 will be described according to the discussion of FIG. 10 below.
- T ⁇ T max L i ⁇ L 1 a ⁇ ⁇ log ⁇ ⁇ L i + b L 1 ⁇ L i ⁇ L 2 T min L i ⁇ L 2 ⁇ ,
- a T min ⁇ L 2 - T max ⁇ L 1 log ⁇ ⁇ L 2 - log ⁇ ⁇ L 1
- ⁇ b T max ⁇ L 1 - a ⁇ ⁇ log ⁇ ⁇ L 1 .
- the fail dark curve 501 is used to compute a required duty cycle for a given transmittance.
- the fail dark curve 501 is approximated by three linear functions separated by transition points 506 and 507 , the first linear function 510 being defined between point 509 and transition point 506 , the second linear function 511 being defined between transition point 506 and transition point 507 , and the third linear function 512 being defined between transition point 507 and point 508 .
- the transition point 506 occurs at about 6% duty cycle and 5.5% transmissivity; the transition point 506 occurs at about 16% duty cycle and 27.5% transmissivity.
- the transition points and linear fit parameters are typically stored in memory 269 within the set of parameters 286 .
- a sensor response curve relating incident light level Li to measured photocurrent of the light sensor is required.
- a typical sensor response curve 800 is shown in FIG. 16 .
- sensor response is approximately linear and the slope of sensor response curve 800 is typically stored in memory 269 as one of the set of parameters 286 .
- a useful feature of AVT eye glasses 10 is that the spectral response of the sensor approximate the response of the human eye.
- FIG. 17 shows graph 810 of a typical spectral response, the spectral response curve 820 being reasonably close to the response of the human eye 830 .
- the light sensors 202 , 244 , and 261 are part APDS-9003 from Avago Technologies Corporation and the graphs of FIGS. 16 and 17 are taken from the corresponding data sheet.
- the desired transmittance T is computed from the overall transmittance response function 295 for a given ambient light level Li and then the duty cycle D for the desired transmittance T is derived from LCD response curve 500 to control the transmissivity of lenses 12 and 14 .
- the duty cycle D for the desired transmittance T is derived from LCD response curve 500 to control the transmissivity of lenses 12 and 14 .
- T_max For ambient illumination less than L 1 falling on the AVT eye glasses 10 , lenses 12 and 14 are turned off transmitting light at a constant maximum lens transmittance, T_max.
- T_min minimum transmittance
- the lens control generally being limited by duty cycle or by polarization efficiency of the inner and outer lens substrates.
- the extent and the slope of the controlled region 290 of the transmittance curve are adjusted to a new extent and a new slope.
- the point 294 may be (4000, 240); after adjustment the point 294 may become (5000, 300).
- Alternative embodiments may restrict either the L 1 or the L 2 adjustment by a wearer.
- FIG. 11 is a pseudocode listing of a control program 300 executed by microprocessor 268 as program instructions 285 and controlling the various functions of AVT glasses.
- FIGS. 8 , 9 and 10 are also useful to understanding the operation of control program 300 .
- Control program 300 has a first hardware interrupt procedure 302 , a second hardware interrupt procedure 315 , a software interrupt procedure 306 executed at microprocessor boot up, a “Run” procedure 308 which executes the main loop of the program, and three subroutines 320 , 325 and 327 which perform computational functions as explained below.
- A/D converter 264 is read to measure photodetector voltage referred to as photovoltage below.
- Timer 1 is the internal timer 263 of microprocessor 268 .
- Microprocessor 268 can monitor and respond to hardware interrupts, redirecting program flow accordingly.
- First hardware interrupt procedure 302 is triggered by an interrupt created by attempted communications on serial interface 271 .
- Code associated with hardware interrupt procedure 302 allows parameters to be entered externally and stored in memory 269 .
- the minimum ambient light level L_min is entered in units of cd/m ⁇ 2, otherwise the default value is selected.
- the default L_min is in the range of 5 to 40 cd/m ⁇ 2 and typically set to 15 cd/m ⁇ 2.
- First “if structure” 310 is checked each time loop 1 repeats and executes a set of instructions if a transition from a low to high voltage level of square wave signal 287 is detected by the microprocessor.
- the set of instructions in first “if structure” 310 begin by starting timer 1 to counting, then the photovoltage is measured and converted to an ambient light luminance value L_in and the GATE line is then set to Vcc.
- the control program 300 limits the slew rate of PWM signal 273 according to the value of gamma in second “if structure” 311 .
- “Run” procedure includes third “if structure” 312 which is checked each time loop 1 repeats. Third “if structure” 312 compares timer 1 with count 2 . If enough time has elapsed so that timer 1 has developed a count greater than count 2 then GATE line is set to 0 V and timer 1 is reset to zero count.
- DutyCycle subroutine 325 returns a computed duty cycle value D for a given transmissivity T.
- Duty cycle subroutine 325 uses the linear fit parameters associated to linear functions 510 , 511 and 512 described according to the LCD response graph of FIG. 10 .
- T 1 and T 2 are the transmissivities at points 506 and 507 of the LCD response graph.
- D_min is the minimum duty cycle allowed and D_max is the maximum duty cycle allowed, having typical values of 5% and 50%, respectively.
- D is that the maximum of the value given by the linear function 510 or D_min; for T>T 2 , D is the minimum of the value given by the linear function 512 or D_max; otherwise D is the value given by the linear function 511 .
- Calibration of eyeglasses 10 is accomplished according to apparatus configurations shown in FIGS. 12A and 12B and according to the method shown in FIG. 13 .
- the calibration method is suitable for eyeglasses using the digital electronic circuit 260 or similar. Similar calibration methods are conceived for the analog electronic circuits 200 and 240 .
- FIG. 12B shows a second calibration configuration 660 suitable for calibrating the transmissivity of eyeglasses 658 .
- Computer 651 has an interface 654 to calibrated light source 652 , the interface 654 allowing for automatic programming of the luminant intensity of light source 652 .
- the lenses 657 held within eyeglasses 658 are positioned to face the light source.
- a serial interface 653 is connected between computer 651 and the eyeglasses for programming the duty cycle of the PWM drive voltage for lenses 657 therein.
- a calibrated photodetector 665 is placed behind the eyeglass lens facing the calibrated light source 652 and made to detect light from the light source as transmitted through the lens, calibrated photodetector 665 connected to computer 651 by a computer interface 666 .
- the computer has a program that can vary the duty cycle of lenses 657 and for each duty cycle, download the corresponding measured light intensity from calibrated photodetector 665 .
- the values can be stored according to patient and product number for future reference
- FIG. 13 is a flowchart of a calibration method 600 used in conjunction with the first and second calibration configurations.
- the method begins in the step 601 wherein the PC calibration program is made to run on computer 651 .
- the eyeglasses are also connected by interface 653 to computer 651 in step 602 , the eyeglasses having the electronic circuit 260 therein.
- a calibration program is downloaded to the memory of the eyeglasses in step 604 using the interface 653 .
- the calibration program contains program instructions to be executed by the microprocessor 268 to measure and communicate the photovoltage V from the eyeglasses light sensor.
- the calibration program also contains program instructions for accepting instructions via interface 653 to set the duty cycle of PWM signal that is driving lenses 657 .
- step 606 computer 651 sets light source 652 to a first predetermined intensity L and then in step 608 microprocessor 268 measures first photovoltage V corresponding to the light detected by the eyeglasses. Steps 606 and 608 are repeated in loop 609 for at least second and third predetermined intensities and for second and third measured voltages. In step 610 the slope of measured voltage V versus light intensity L is determined and stored as the eyeglasses light sensor response 613 .
- Step 611 is performed next, wherein the light source 652 is moved horizontally to determine the horizontal field of view of the eyeglasses light sensor and then moved vertically to determine the vertical field of view of the eyeglasses light sensor. While moving light source 652 , the photovoltage is measured and reported by the microprocessor and displayed on the computer. Typically, the position of the light source and the measured photovoltage is recorded by hand. The photovoltage falls off with position determining the edges of the field of view which is calculated according to the geometry of the apparatus. The field of view 615 is stored in computer 651 for later download to the eyeglasses.
- the set of data points (Tk, Dk), measured in loop 621 for a set of k duty cycles, are stored in the eyeglasses as an LCD response lookup table.
- the DutyCycle subroutine 325 is replaced with a different subroutine that performs the following steps to look up a duty cycle D 0 for a given input transmissivity T 0 : in the first step, looking up two T values in the lookup table nearest T 0 in value, T 1 and T 2 ; then, looking up the duty cycles D 1 and D 2 corresponding to T 1 and T 2 ; interpolating between (T 1 , D 1 ) and (T 2 , D 2 ) to compute D 0 ; and returning D 0 to the calling program.
- physicians program 700 is conceived for use alongside eyeglasses 10 , the physicians program being operated on a personal computer normally situated in the physician's office in proximity to the patient for which the eyeglasses are intended for use.
- the physicians program is initiated in step 702 which causes a Microsoft Windows program to operate in step 704 .
- the Windows program checks that the eyeglasses are connected to the computer in step 708 and that the eyeglasses are running a valid operational program; if not, then a warning that the eyeglasses are not ready is displayed by the computer in step 709 . If the eyeglasses are connected to the computer and running a valid operational program, then a patient data screen is displayed in step 710 .
- the physician then enters the patient data in step 714 and a desired lower light level L_min in units of cd/m2 in step 716 .
- the physicians program 700 then checks if the light level is in the proper range, which is typically [0.1, 500] cd/m2. If no value is entered, a default value of 15 cd/m2 is chosen in the preferred embodiment. If outside the proper range, then a prompt to reenter the data is displayed on the computer in step 719 . If the light level is in range, then the patient data and the light level is downloaded to the eyeglasses in step 720 and a message to the effect that the eyeglasses have been successfully programmed is displayed in step 722 . The physician's program ends at step 725 by exiting the program.
- FIG. 15 shows a typical physician's computer form display associated to the physician's program 700 , the display fields being a patient name 750 , patient street address 751 , patient city address 752 , patient state 753 , patient zip code 754 , date of service 755 and the minimum light level 760 .
- Eye glasses 10 along with circuit 260 are considerably flexible in application due to programmability.
- Other embodiments may be conceived to take advantage of the programmability as a result.
- different battery types may be accommodated by extending the program of interrupt procedure 302 to enter a battery type and then the corresponding battery voltage taken into account in computing duty cycles.
Abstract
Adjustable variable transmissivity (AVT) eyewear for patients, the AVT eyewear having a liquid crystal lens driven by an electronics circuit so that light transmitted through the lens is detected, the transmitted light being driven to a setpoint by the electronics circuit according to feedback control on the liquid crystal lens drive voltage duty cycle. In another embodiment, light detected from the ambient is detected and the resulting photocurrent value processed by a microprocessor included in the electronics circuit, the microprocessor driving the liquid crystal lens to a desired transmissivity, the desired transmissivity given by a computed transmissivity curve. The computed transmissivity curve may be controlled by the physician or in an alternate embodiment controlled by the patient according to a set of electronic controls on the AVT eye glasses.
Description
- The present invention relates generally to the field of treatment for age related macular degeneration. More specifically, the invention is a set of eye glasses which electronically dim and brighten according to ambient light conditions.
- People with age related macular degeneration (ARMD) and similar diseases affecting the ocular media have long retinal adaptation times leading to poor visual acuity during adaptation. Dark adaptation times may be measured in tens of minutes in typical cases. The lack of visual acuity may cause serious mobility problems in people with ARMD, especially near curbs and steps in bright sunlight. Generally, there are problems in the aged relating to contrast sensitivity in varying lighting conditions leading to vision problems while driving during the night time.
- Ophthalmologists have long sought a prescriptive solution wherein the ARMD patient may be fit with light absorbing eye glasses that restrict the amount of light reaching the patient's eyes thereby increasing visual acuity. The eye glasses must adapt to a wide range of lighting conditions ranging from the office environment wherein light luminance levels are typically on the order of 12-18 cd/m2 to a bright sunny day outside, wherein luminance levels may be on the order of 5000 cd/m2. The need for light absorbing eye glasses with a wide dynamic range thus exists. Furthermore, the eye glasses must respond quickly to keep the retinal illumination level near an ideal value so that dark adaptation effects are not impaired and retinal bleaching does not occur. As for contrast sensitivity, polarization arrangements yielding a yellow lens color is advantageous to achieving the greatest contrast sensitivity.
- While light absorbing eye glasses exist in the prior art, there are fundamental flaws in the prior art designs. One major flaw is the inability of the ophthalmologist to adjust for the patient to patient variation of dark to bright transmission ranges, and for the patient's overall illumination response. The present invention allows for such control by the ophthalmologist. Secondly, control group studies of subject response to light absorbing eye glasses were made according to Ross and Mancil in “Design and Evaluation of Liquid Crystal (LC) Dark Adapting Eye Glasses for Persons with Low Vision”, Final Report, Project #C776-RA, Atlanta V.A. Rehab Center, March 1997, indicating that subjects preferred to maintain some control over the lens behavior of the light absorbing eye glasses. The present invention allows for limited patient manual override through the use of controls on the ear pieces, one control setting the low light level characteristic of the lens function and the other control setting the upper light level limiting characteristic of the lens function.
- Examples of beneficial applications of adjustable variable transmissivity eyewear (AVT) of the present invention are conceived for medical applications, sports applications and occupational applications. For medical use, AVT eyewear is useful in the treatment of retinal pigmentosa, ocular albinism, choroidermia, gyrate atrophy, corneal scarring, cataracts and ureitis. A variety of outdoor sporting activities including fishing, hunting, skiing, golf and baseball may benefit from the present invention. Occupational safety applications are conceived for driving, heavy equipment operation, low light military or police maneuvers, oxyacetylene welding and glassblowing.
- Apparatus and methods are described herein which teach the construction and the use of light absorbing adjustable variable transmissivity (AVT) eye glasses. AVT eye glasses comprise a set of frames and a pair of lenses attached to the frames, the set of lenses being made of liquid crystal substrates that change their transmittance upon application of an electric potential. The frames are made to fit a wearer's face over prescription eyewear and to house electronics circuits and batteries for controlling the function of the lenses. Additionally, the frames allow for a light pipe connected to a light sensor to detect ambient light from the direction forward of the wearer with variable field of viewing using light pipe plugs to restrict the angle of view as well as the overall field of view. The frames have earpieces attached to which the electronics substrates may be housed and to which a left control and a right control are fixed, the left and right controls electronically connected to electronics circuits contained on the electronics substrates. In an alternate embodiment, the light pipe is configured to detect transmitted light through the lens to maintain a constant light level to the wearer's eye. In yet another embodiment the electronics substrate may be housed in the frames instead of the earpieces.
- The liquid crystal lens is comprised of two substrates fixed together and having a liquid crystal material between them. The substrates are further comprised of an Indium Tin Oxide (ITO) coated glass substrate with a polarizing film on one side and an alignment layer on the other side. A fail dark configuration of the alignment and polarizing layers is taught wherein the polarizers are set vertical and the alignment layers are set at −45 degrees and +45 degrees from the horizontal. The fail dark lens configuration causes the lens transmittance to go to a low value when power is removed from the lenses. A fail light configuration is taught wherein the polarizers are set at a 90 degree angle from each other, one being in the vertical and the second being in the horizontal, the alignment layers being at −45 degrees and +45 degrees to the horizontal, respectively. The fail light lens configuration causes the lens transmittance to go to a high value when power is removed from the lenses. Typical fail dark transmittance is 6% and typical fail light transmittance is 29%.
- Electronic circuits are taught to accomplish the lens control under different conditions. In the condition wherein ambient light is sensed, an analog electronics circuit and a digital electronics circuit is taught, the latter including the use of a microprocessor. An analog feedback control circuit is taught for the situation when transmitted light is sensed and it is desired to fix the transmitted light level at a given value. Electronics circuits in the preferred embodiment of the present invention utilize a variable duty cycle of alternating current square wave signal to affect control of the lens average voltage and thereby the lens transmissivity.
- In the case of the microprocessor based electronics, methods are taught to automatically adjust the light level according to a desired transmissivity curve. In the preferred embodiment, the desired transmissivity curve is the Weber-Fechner logarithmic response. In other embodiments linear response or other response curves may be utilized in the present invention.
- Moreover, methods are taught to utilize controls to affect the transmissivity curve, specifically upper and lower light level set points for the light sensor to control the duty cycle for maximum and minimum transmission of light through the lens.
- A software program for controlling the function of variable transmissivity eye glasses is explained taking into account the automatic light level adjustment according to a desired transmissivity curve and taking into account the use of controls.
- The disclosed inventions will be described with reference to the accompanying drawings, which show important sample embodiments of the invention and which are incorporated in the specification hereof by reference, wherein:
-
FIG. 1A is a frontal view of a first embodiment AVT eye glasses showing the lens and frames. -
FIG. 1B is a top view of a first embodiment AVT eye glasses showing the frames and earpieces. -
FIG. 1C is a side view of a first embodiment AVT eye glasses while partially folded. -
FIGS. 1D and 1E are right and left side views, respectively, of a first embodiment AVT eye glasses while unfolded. -
FIG. 2A is a cross-sectional view of a light plug situated in the AVT eyeglasses frame. -
FIG. 2B is a perspective view of a light plug. -
FIG. 2C is a frontal view of the light plug situated in the eyeglasses frame. -
FIG. 2D is a cross-sectional view of a light pipe plug situated in the AVT eye glasses frame. -
FIG. 2E is a perspective view of a light pipe plug. -
FIG. 3A is a frontal view of the of second embodiment AVT eye glasses showing the frames and light sensor position behind the lens. -
FIG. 3B is a top view of the of second embodiment AVT eye glasses showing the frames and light sensor position behind the lens. -
FIG. 3C is a side view of the second embodiment AVT eye glasses. -
FIG. 3D is a cross-sectional view of a light pipe plug situated behind the AVT eye glasses lens. -
FIG. 4 is a geometric drawing of the lens structure in the preferred embodiment of the present invention. -
FIG. 5A is a front perspective drawing of the inner and outer lens substrates with top down view looking towards the front face of the lenses, the drawing pertaining to the fail dark lens substrate arrangement. -
FIG. 5B is a front perspective drawing of the inner and outer lens substrates with top down view looking towards the front face of the lenses, the drawing pertaining to the fail light lens substrate arrangement. -
FIG. 6 is a block diagram of the electronic circuitry for the AVT glasses with direct ambient photosensing. -
FIG. 7 is a block diagram of the electronic circuitry for the AVT glasses with photosensing from behind the lens. -
FIG. 8 is a block diagram of the electronic circuitry for the AVT glasses with direct ambient photosensing and using a microprocessor for control in the preferred embodiment. -
FIG. 9 is a graph of AVT glasses transmittance curves showing the preferred embodiment transmissivity curve. -
FIG. 10 is a graph showing the LCD response curve of transmissivity versus duty cycle in the preferred embodiment of the present invention, curves for fail dark and fail light modes are shown. -
FIG. 11 is pseudocode listing of the modulation software used by the microprocessor to control the function of the eyeglasses and the lenses. -
FIG. 12A is block diagram of an apparatus to calibrate the light sensor of the eyeglasses. -
FIG. 12B is a block diagram of an apparatus to calibrate the transmissivity of the eye glass lenses. -
FIG. 13 is a flow chart of a preferred method to calibrate the AVT eyeglasses. -
FIG. 14 is a flow chart of a physician's program. -
FIG. 15 is a graphical depiction of the display page of the physician's program. -
FIG. 16 is a graph of a typical light sensor response. -
FIG. 17 is a graph of a typical light sensor spectral response. - The numerous innovative teachings of the present application will be described with particular reference to the presently preferred embodiments (by way of example, and not of limitation). The present invention teaches an apparatus and corresponding methodology for making and using adjustable variable transmissivity (AVT) eyeglasses.
-
FIGS. 1A , 1B, 1C show the first embodiment frontal view, top view and side view, respectively, of partially closedAVT eyeglasses 10 incorporating the present invention.FIG. 1A is a frontal view of AVTeyeglasses 10 which includelens 12 andlens 14 mounted inframe 16.Lens 12 andlens 14 have electronically controllable optical density for controlling the amount of light transmitted to a wearer's eyes. The structure oflens Sensor element 30 is integrated into thebridge area 26 offrame 16 and contains alight sensor 32 which in the first embodiment senses ambient light in front ofeyeglasses 10. Attached to frame 16 by hinges 8 and 9, areearpieces - Referring to
FIGS. 1D and 1E , side views of normally openedAVT eyeglasses 10 show that anelectronics circuit 33 is integrated intoearpiece 20,electronics circuit 33 being electrically attached tolight sensor 32 and tobatteries 22 contained inbattery compartment 21.Ear piece 18 also has leftcontrol 36;ear piece 20 also hasright control 37, the controls used in the preferred embodiment to set the lower and upper light level limits for electronic control of the duty cycle for maximum and minimum transmission of the light through the lens. An on/off switch may be incorporated intoear pieces electronics circuit 33. Thecontrols - The placement of
controls -
FIGS. 2A , 2B and 2C show details ofsensor element 30 which is comprised of ahole 29 inbridge area 26 having aclear plug 25, anoutput aperture 28 b, and alight sensor 32 fixed behind theoutput aperture 28 b. Clear plug 25 has a clear hole withinner surface 35 to which aninput aperture 28 a is mounted as shown inFIGS. 2B and 2C . The input and output apertures create a field ofview 27 from which light is collected ontolight sensor 32 which measures the ambient light luminance collected within field ofview 27 from the front ofAVT eye glasses 10.Output aperture 28 b may have its center offset from the center ofinput aperture 28 a, the offset being in the vertical or horizontal direction by an offsetdistance 31. A vertical offsetdistance 31 causes a vertical shift of the field of view while a horizontal offsetdistance 31 causes a horizontal shift of the field of view. The horizontal plane is defined as the plane containing the center point of both lenses. The vertical plane is a plane perpendicular to the horizontal plane for which all points are equidistant from the center point of both lenses. - Clear plugs with different fields of view and different offset distances will be available to the ophthalmologist to allow for the setting of different fields of view, a suitable clear plug being selected and inserted into
bridge area 26 as prescribed for the wearer. The geometry of the input and output apertures may be selected to restrict light gathering capability and to set the field of view, for example the apertures may be elliptical with the major axis oriented horizontally and the minor axis oriented vertically to restrict bright light from the sun or overhead lights. The preferred embodiment horizontal field of view is +/−30 degrees about the vertical plane. The preferred embodiment vertical field of view is +10 degrees upwards and −45 degrees downward from the horizontal plane. -
FIGS. 2D and 2E show detail of an alternate embodiment of a sensor element,sensor element 50 which is comprised of a clear plasticlight pipe 55 inserted intohole 59 ofbridge area 26 havinginput aperture 58 a on afirst surface 61 a, anoutput aperture 58 b on asecond surface 61 b and alight sensor 52. The input and output apertures create a field ofview 57 so that light is collected ontolight sensor 52 which measures ambient light luminance collected within field ofview 57 to the front ofAVT eye glasses 10.Shoulder 62 onlight pipe 55 abuts to theeye glass frame 16.Input aperture 58 a andoutput aperture 58 b may be formed by depositing metal onsurfaces Output aperture 58 b may have its center offset from the center ofinput aperture 58 a, the offset being in the vertical or horizontal direction by an offset distance (not shown). As withclear plugs 25, light pipes with different fields of view and different offset distances may be inserted intobridge area 26 as required for the wearer. -
FIGS. 3A , 3B, 3C show a second embodiment ofAVT eyeglasses 11 of the present invention.FIG. 3A is a frontal view of AVTeyeglasses 11 which includeslens 12 andlens 14 mounted inframe 16,lens 12 andlens 14 have electronically controllable optical density as in the first embodiment.Sensor element 40 is contained in thebridge area 26 offrame 16 and has alight sensor 42.Light sensor 42 is positioned behindlens 12 so that it senses light that is transmitted throughlens 12.AVT eyeglasses 11 also have earpieces, an electronics circuit, controls and a battery compartment similar to those described forAVT eyeglasses 10. -
FIG. 3D shows detail ofsensor element 40 which is comprised of alight pipe 49 havinginput aperture 48 a andoutput aperture 48 b, a mountingassembly 41 and alight sensor 42. The input and output apertures create a field ofview 47 from which light is collected ontolight sensor 42 which measures the luminance of light collected within field ofview 47 and transmitted throughlens 12 to the front ofAVT eye glasses 10.Input aperture 48 a andoutput aperture 48 b are integrated intolight pipe 49,input aperture 48 a being adjacent to the rear surface oflens 12. As before,input aperture 48 a may be offset fromoutput aperture 48 b to move the field of view vertically or horizontally. -
FIGS. 4 , 5A and 5B show the structure ofLCD lens 100 of the present invention. InFIG. 4 ,lens 100 corresponds tolens 12 andlens 14 ofFIGS. 1-3 .Lens 100 is comprised of a twisted nematicliquid crystal material 110 sandwiched between aninner substrate 101 nearest the wearer'seye 103 and anouter substrate 102 nearest the object orlight source 105. The incident light hasdirection vector 117 and the transmitted light hasdirection vector 109. Theouter substrate 102 is comprised of several layers and components. Starting from the front surface and moving towards theeye 103, an input polarizingthin film 104 is coated onto a first electrically conductiveITO glass substrate 106, the rear facing surface being coated with a first layer of Indium Tin Oxide (ITO) 107 upon which is a first thin filmpolyimide alignment layer 108 which is scribed in a first direction. The firstpolyimide alignment layer 108 is in contact with liquidcrystalline material 110. A second thin filmpolyimide alignment layer 112 is coated onto to asecond ITO layer 113 on the front facing surface ofglass substrate 114 and scribed in a second direction. The rear facing surface ofglass substrate 114 is coated with an output polarizingthin film 116. As is known in the art, an electric potential is applied between the first conductingITO glass substrate 106 and the second conductingITO glass substrate 114 to affect the orientation of the liquid crystal and thereby change the transmissivity of thelens 100. In the preferred embodiment, the applied electric potential is an alternating potential. - In the exemplary embodiment the polarizing film is preferably made of organic dye in base film (polyvinyl alcohol, or PVA), product number NPF Q-12 from Nitto Denko with transmittance of about 41%, polarizing efficiency of about 89%, hue (NBS-a) of −0.6 and hue (NBS-b) of 1, giving rise to a yellow lens color with no applied voltage and a dark blue lens color with applied alternating voltage. Electrical leads are attached by silver epoxy and the lens substrates are surrounded with an adhesive ring.
-
FIG. 5A shows a fail dark embodiment of thelens 100 so that when the electric potential is zero betweeninner substrate 101 andouter substrate 102, thelens 100 has a low transmissivity. TheFIG. 5A is drawn so that the surfaces while looking down at the page are the front facing surfaces of the two lens substrates looking towards the wearer's eye; a further description being that the transmittedlight vector 109 is going into the page inFIG. 5A . In the preferred embodiment, the fail dark transmissivity value is approximately 6%. In other embodiments the fail dark transmissivity may achieve a lower value. In the fail dark configuration, the polarizer ofouter substrate 102 is arranged to transmit linear polarization infirst direction 131 and alignment layer scribed insecond direction 132, thefirst direction 131 being vertical and thesecond direction 132 being at an angle of 45 degrees clockwise from horizontal. Furthermore, the polarizer ofinner substrate 101 is arranged to transmit linear polarization inthird direction 133 and alignment layer scribed infourth direction 134, thethird direction 133 being vertical and thefourth direction 134 being 45 degrees counterclockwise from horizontal. -
FIG. 5B shows a fail light embodiment of thelens 100 wherein when the electric potential is zero betweeninner substrate 101 andouter substrate 102, thelens 100 has a high transmissivity.FIG. 5B is drawn similar toFIG. 5A so that the transmittedlight vector 109 is going into the page. In the alternate embodiment, the fail light transmissivity value is approximately 30%. In other embodiments, the fail light transmissivity may be higher. In the fail light configuration the polarizer ofouter substrate 102 is arranged to transmit linear polarization infifth direction 151 and alignment layer scribed insixth direction 152, thefifth direction 151 being vertical and thesixth direction 152 being 45 degrees clockwise from the horizontal direction. Furthermore, the polarizer ofinner substrate 101 is arranged to transmit linear polarization inseventh direction 153 and alignment layer scribed ineighth direction 154, theseventh direction 153 being horizontal and the eightdirection 154 being 45 degrees counterclockwise from the horizontal direction. -
FIG. 6 is a block diagram of a first embodimentelectronic circuit 200.Electronic circuit 200 provides electronic control of the transmissivity oflens element 218 allowing for a certain fraction of incident light 201 to fall on a wearer'seye 219 and is comprised of a dc/dc boost converter 221 connected to abattery 220; alight sensor 202; anamplifier 204 connected tolight sensor 202, theamplifier 204 havinggain control 205 andbias control 206; apulse width modulator 210 connected toamplifier 204; anoscillator 211 driving the frequency and timing of thepulse width modulator 210; abuffer amplifier 214 connected tolens element 218 for conditioning adrive signal 216 to drivelens element 218, the input ofbuffer amplifier 214 connected topulse width modulator 210 and generatingPWM signal 212.Incident light 201 which is directly from the ambient, falls onlight sensor 202 where the detected light quanta are converted to aphotocurrent 203.Photocurrent 203 is sensed byamplifier 204 and converted to aphotovoltage 208. The gain betweenphotovoltage 208 andphotocurrent 203 is set bygain control 205 and a voltage offset being set bybias control 206. In the preferred embodiment,gain control 205 andbias control 206 are factory set. Thephotovoltage 208 determines the duty cycle of thePWM signal 212. In this exemplary embodiment,PWM 210 is a 555 timer chip operating in PWM mode as known in the art, withphotovoltage 208 driving the 555 timer's control voltage input.Amplifiers -
FIG. 7 is a block diagram of a second embodimentelectronic circuit 240.Electronic circuit 240 provides electronic control of the transmissivity of lens element 242 allowing for a certain fraction of incident light 241 to fall on a wearer'seye 243 and is comprised of alight sensor 244 generatingphotocurrent 234; an integratingtransimpedance amplifier 245 connected tolight sensor 244 havingsensitivity control 246 and anoutput photovoltage signal 235 proportional tophotocurrent 234.Electronic circuit 240 further comprises acomparator 247 withvoltage reference 253; acharging circuit 250 connected to capacitor 251 for charging a capacitor 251 havingpeak voltage reference 248, avoltage follower 254 connected to capacitor 251 and chargingcircuit 250; a pulsewidth modulator circuit 256 connected to the output ofvoltage follower 254 and driven by anoscillator 255, and abuffer amplifier 258 connected toPWM circuit 256 and to lens element 242 for driving lens element 242.PWM circuit 256 produces aPWM signal 259 of variable duty cycle and fixed period, the period being determined byoscillator 255. -
Photovoltage signal 235 is connected to the input ofcomparator 247 which enables charging signal 237 a or dischargingsignal 237 b depending upon a comparison between thephotovoltage signal 235 and thereference voltage 253. If the photovoltage signal is less than the reference voltage, then thecharge signal 237 a is enabled and chargingcircuit 250 allows capacitor 251 to be charged to acapacitor voltage 252 determined bypeak voltage reference 248. If the photovoltage signal is greater than the reference voltage, then thedischarge signal 237 b is enabled and chargingcircuit 250 discharges capacitor 251 causing thecapacitor voltage 252 to go to ground. If the photovoltage signal is approximately the same as the reference voltage, then neither ofsignals capacitor voltage 252 is not altered except for circuit leakages. - A
voltage follower 254 creates current bufferedPWM input voltage 238 proportional tocapacitor voltage 252,PWM input voltage 238 determining the duty cycle ofPWM signal 259.PWM circuit 256 is connected to bufferamplifier 258, which in turn drives the lens element.PWM circuit 256 may be a 555 timer chip operating in PWM mode as known in the art, withPWM input voltage 238 driving the 555 timer's control voltage input. The duty cycle varies from about 5% to about 50%. -
FIG. 8 is a block diagram of a third embodimentelectronic circuit 260.Electronic circuit 260 provides electronic control of the transmissivity oflens element 282 allowing for a certain fraction of incident light 262 to fall on a wearer'seye 280 and is comprised of a DC/DC converter 265 connected tobattery 266 and having outputDC voltage Vcc 259 for powering the components ofcircuit 260; a light sensor 261 forsensing incident light 262; acrystal oscillator 267 oscillating at frequency f1; asquare wave oscillator 283 oscillating at frequency f2 producingsquare wave signal 287 connected to amicroprocessor 268 and an ANDgate 284;microprocessor 268 having an A/D converter 264 connected to light sensor 261 and atimer 263 connected tocrystal oscillator 267,microprocessor 268 further havingmemory 269 which containsprogram instructions 285 for operation and for generating a pulse width modulated signal; and aserial interface 271 for communications withmicroprocessor 268. -
Electronic circuit 260 also has acharge pump circuit 279 for generating an alternating current drive signal and further contains an ANDgate 284 with one input beingsquare wave signal 287 and a second input beingGATE line 272 which is connected to and driven bymicroprocessor 268. The output of ANDgate 284 isPWM signal 273 which is connected to chargepump circuit 279. -
Charge pump circuit 279 is comprised of anon-inverting buffer 270 a and invertingbuffer 270 b, a set ofpolarized capacitors resistors diodes Capacitor 275 a has its negative side connected to thenon-inverting output 274 a ofbuffer 270 a and its positive side connected to the cathode ofdiode 277 a, to first end ofresistor 276 a and tooutput line 278 a. The anode ofdiode 277 a and the second end ofresistor 276 a are tied to ground.Capacitor 275 b has its positive side connected to the invertingoutput 274 b ofbuffer 270 b and its negative side connected to the anode ofdiode 277 b, to a first end ofresistor 276 b and tooutput line 278 b. The cathode ofdiode 277 b and the second end ofresistor 276 b are tied to ground. The voltage acrossoutput lines - In another embodiment of
electronic circuit 260, the AND gate may be synthesized in the program logic contained in program instructions and theGATE line 272 becomes equivalent to PWM signal 273. - In operation, incident light 262 falls on light sensor 261 wherein the detected light quanta are converted to photocurrent and then to a photovoltage proportional thereto. The photovoltage is read by A/
D converter 264 in conjunction withmicroprocessor 268 to determine a measured incident light luminance which is used according toprogram instructions 285 to driveGATE line 272 which sets the duty cycle ofPWM signal 273. Besidesprogram instructions 285,microprocessor 268 has stored inmemory 269parameters 286 including at least an upper transmissivity limit, T_max, a lower transmissivity limit, T_min, and incident light levels L1 and L2, associated to the transmissivity limits. In the preferred embodiment, T_min and T_max are predetermined so thatelectronic circuit 260 is calibrated during manufacture to produce T_min at about 50% PWM signal duty cycle and T_max at about 5% duty cycle. T_max is typically 29% transmissivity and T_min is typically 6% transmissivity.Program instructions 285 will be described according to the discussion ofFIG. 10 below. -
Microprocessor 268 hasserial interface 271 for downloadingprogram instructions 285 andparameters 286.Serial interface 271 may be wired or it may be wireless as in a Bluetooth transmitter and receiver. In the preferred embodiment,serial interface 271 is of type I2C andmicroprocessor 268 is the MP430 ultra low power MCU available from Texas Instruments, Inc. - Third embodiment
electronic circuit 260 has advantages in several aspects: it is easily programmable on the ophthalmologist's bench with the patient, upgradeable to include new features, and suitable for cost effective manufacturability wherein the upgraded features may include different lens structures with different transfer.Electronic circuit 260 may be operated in a direct view mode or in a transmitted light mode. In the transmitted light mode consistent with secondembodiment AVT eyeglasses 11,microprocessor 268 is programmed to keep the transmitted light through the lens constant at a prescribed illumination using PID feedback control algorithms known in the art. The direct view mode consistent with firstembodiment AVT eyeglasses 10,microprocessor 268 is programmed to produce a lens transmissivity for a given input light level. -
FIG. 9 is a graph of atypical transmittance function 295 employed for direct view modeAVT eye glasses 10. The abscissa is the ambient luminance measured in cd/m2 (L_in) and the ordinate is the transmissivity throughlenses transmittance function 295 is typical of a fail dark mode of operation and is comprised of three regions, the controlledregion 290, the fullypowered transmittance region 291, and the powered offtransmittance region 292. The fullypowered transmittance region 291 transitions to the controlledregion 290 at an ambient luminance of L1 corresponding to point 293 on the transmittance curve. The controlledregion 290 transitions to the powered offtransmittance region 292 at luminance L2 corresponding to point 294 on the transmittance curve. - In the preferred embodiment, the transmittance function for the controlled
region 290 takes the form of the Weber Fechner law which is logarithmic in response.Transmittance function 295 is summarized according to the formula: -
- wherein T*Li is the transmitted light level (luminance on the eye), Li is the ambient light level (luminance on the lens), Tmax is the maximum transmittance of the
lenses lenses -
- The Weber Fechner law is known in the art to most closely approximates a human sensory response function, however, other embodiments are conceived wherein other functions may be used, for example a linear response.
- The graph of
FIG. 10 shows two exemplary LCD response curves, a fail lightmode response curve 500 and a fail darkmode response curve 501, both curves having duty cycle as theabscissa 503 and transmittance T as theordinate 502. For a given lens assembly, the transmittance will take on a fixed maximum and a fixed minimum. In the fail light case according tocurve 500,maximum transmittance point 504, occurs for small duty cycle and aminimum transmittance point 505, occurs near the point of maximum duty cycle, the maximum duty cycle being 50% in the exemplary embodiment. In the fail dark case according tocurve 501,maximum transmittance point 508, occurs near the maximum duty cycle andminimum transmittance point 509, occurs for small duty cycle. An AVT lens system operating in fail light mode will have maximum transmittance and maximum light on a wearer's eye when the voltage across the lens goes to zero. An AVT lens system operating in fail dark mode will have minimum transmittance and minimum light on a wearer's eye when the voltage across the lens goes to zero. The preferred mode of operation is to fail dark for the present invention, but either mode may be used. - In practice, the fail
dark curve 501 is used to compute a required duty cycle for a given transmittance. To simplify and speed up the computation, the faildark curve 501 is approximated by three linear functions separated bytransition points linear function 510 being defined betweenpoint 509 andtransition point 506, the secondlinear function 511 being defined betweentransition point 506 andtransition point 507, and the thirdlinear function 512 being defined betweentransition point 507 andpoint 508. In the preferred embodiment, thetransition point 506 occurs at about 6% duty cycle and 5.5% transmissivity; thetransition point 506 occurs at about 16% duty cycle and 27.5% transmissivity. The transition points and linear fit parameters are typically stored inmemory 269 within the set ofparameters 286. - A sensor response curve relating incident light level Li to measured photocurrent of the light sensor is required. A typical
sensor response curve 800 is shown inFIG. 16 . In practice, sensor response is approximately linear and the slope ofsensor response curve 800 is typically stored inmemory 269 as one of the set ofparameters 286. - A useful feature of
AVT eye glasses 10 is that the spectral response of the sensor approximate the response of the human eye.FIG. 17 showsgraph 810 of a typical spectral response, thespectral response curve 820 being reasonably close to the response of thehuman eye 830. In the preferred embodiment using direct detection of ambient light, thelight sensors FIGS. 16 and 17 are taken from the corresponding data sheet. - Referring again to
FIGS. 9 and 10 in operation, the desired transmittance T is computed from the overalltransmittance response function 295 for a given ambient light level Li and then the duty cycle D for the desired transmittance T is derived fromLCD response curve 500 to control the transmissivity oflenses AVT eye glasses 10,lenses AVT eye glasses 10,lens - A useful feature of the present invention is the ability of the wearer to set the
point 293 and thepoint 294 of thetransmittance curve 295, although the AVT eyeglasses are typically set by a trained ophthalmologist in the clinic using a computer interfaced to the eyeglasses.Point 293 may be adjusted by pressing and holding theleft control 36 momentarily in the preferred embodiment wherein the wearer may accomplish setting the light level L1 to the current ambient light level.Point 293 is then (L1, Tmax*L1).Point 294 may be adjusted by pressing and holding theright button 37 momentarily in the preferred embodiment, wherein the wearer may accomplish setting the light level L2 to the current ambient light level.Point 294 is then (L2, Tmin*L2). Whenpoint 294 is changed, the extent and the slope of the controlledregion 290 of the transmittance curve are adjusted to a new extent and a new slope. For example, prior to adjustment thepoint 294 may be (4000, 240); after adjustment thepoint 294 may become (5000, 300). Alternative embodiments may restrict either the L1 or the L2 adjustment by a wearer. - Also in the preferred embodiment, if both the left and
right controls AVT eye glasses 10 resets to default values forpoints points points -
FIG. 11 is a pseudocode listing of acontrol program 300 executed bymicroprocessor 268 asprogram instructions 285 and controlling the various functions of AVT glasses.FIGS. 8 , 9 and 10 are also useful to understanding the operation ofcontrol program 300.Control program 300 has a first hardware interruptprocedure 302, a second hardware interruptprocedure 315, a software interruptprocedure 306 executed at microprocessor boot up, a “Run”procedure 308 which executes the main loop of the program, and threesubroutines D converter 264 is read to measure photodetector voltage referred to as photovoltage below. Timer1 is theinternal timer 263 ofmicroprocessor 268. -
Microprocessor 268 can monitor and respond to hardware interrupts, redirecting program flow accordingly. First hardware interruptprocedure 302 is triggered by an interrupt created by attempted communications onserial interface 271. Code associated with hardware interruptprocedure 302 allows parameters to be entered externally and stored inmemory 269. Incontrol program 300, only one parameter, the minimum ambient light level L_min is entered in units of cd/m̂2, otherwise the default value is selected. In the preferred embodiment the default L_min is in the range of 5 to 40 cd/m̂2 and typically set to 15 cd/m̂2. - A second hardware interrupt
procedure 315 is triggered by an interrupt created when one ofcontrols service 316 associated to theleft control 36 measures the photovoltage at the time of the interrupt and sets the variable L1 to the ambient luminance corresponding to the measured photovoltage. Second interruptservice 317 associated to theright control 37 measures the photovoltage at the time of the interrupt and sets the variable L2 to the ambient luminance corresponding to the measured photovoltage. The interruptprocedure 315 also services the situation wherein both the left and right buttons are pressed simultaneously in third service interrupt 318 which sets L1 and L2 to default values, the default values having been stored in the set ofparameters 286. In an alternate embodiment L1 and L2 refer directly to photovoltage generated from light sensor 261 without converting to luminance. - Software interrupt
procedure 306 occurs shortly after the electronics are powered, software interruptprocedure 306 functioning to initialize the hardware and the variables required for the remainder ofcontrol program 300. The variables are initialized according to values stored inmemory 269 and include T_min, T_max, detector response alpha, ratio beta which is the ratio of frequencies f1/f2, duty cycle coefficient gamma, minimum light level L1, maximum light level L2, and linear fit parameters for LCD response: T1, T2, a1, b1, a2, b2, a3, b3, D_min and D_max, and count2 which determines the PWM pulse width. Additionally, theGate line 272 is set to 0 (zero) V and timer1 is reset to zero count. When the initialization is complete the software interruptprocedure 306 begins to run “Run”procedure 308. - The
program 300 generates PWM signal 273 according to “Run”procedure 308 whereinGATE line 272 is made to go high for a time proportional to count2 and made to go low for the remainder of the period ofsquare wave signal 287. “Run”procedure 308 continuously executes a loop labeledloop 1 inFIG. 11 until the eye glasses are powered off or a hardware interrupt occurs. - First “if structure” 310 is checked each time loop1 repeats and executes a set of instructions if a transition from a low to high voltage level of
square wave signal 287 is detected by the microprocessor. The set of instructions in first “if structure” 310 begin by starting timer1 to counting, then the photovoltage is measured and converted to an ambient light luminance value L_in and the GATE line is then set to Vcc. The transmissivity T is then computed for L_in by callingsubroutine 320 after which the required duty cycle of PWM signal 273 to obtain transmissivity T is calculated by callingsubroutine 325. Once the duty cycle DC is calculated, count2 is computed as count2=DC*beta, count2 determining the positive pulse width inPWM signal 273. Thecontrol program 300 limits the slew rate of PWM signal 273 according to the value of gamma in second “if structure” 311. - “Run” procedure includes third “if structure” 312 which is checked each time loop1 repeats. Third “if structure” 312 compares timer1 with count2. If enough time has elapsed so that timer1 has developed a count greater than count2 then GATE line is set to 0 V and timer1 is reset to zero count.
-
Transmissivity subroutine 320 returns transmissivity T according totransmittance curve 295 ofFIG. 9 wherein T=T_max if L_in is less than L1, T=T_min if L_in is greater than L2, otherwise T is given by the transmissivity function -
T=a*log(L_in)+b. - The slope and the intercept b are computed by
Coefficients subroutine 327 which fits the transmissivity function to the points (L1, T_max) and (L2, T_min). -
DutyCycle subroutine 325 returns a computed duty cycle value D for a given transmissivity T.Duty cycle subroutine 325 uses the linear fit parameters associated tolinear functions FIG. 10 . T1 and T2 are the transmissivities atpoints linear function 510 or D_min; for T>T2, D is the minimum of the value given by thelinear function 512 or D_max; otherwise D is the value given by thelinear function 511. - Calibration of
eyeglasses 10 is accomplished according to apparatus configurations shown inFIGS. 12A and 12B and according to the method shown inFIG. 13 . The calibration method is suitable for eyeglasses using the digitalelectronic circuit 260 or similar. Similar calibration methods are conceived for the analogelectronic circuits - In
FIG. 12A a first calibration configuration 650 for measuring light sensor response is shown. Acomputer 651 has aninterface 654 to a calibratedlight source 652, theinterface 654 allowing for automatic programming of the luminant intensity oflight source 652.Light source 652 is typically a diffuse source similar to Model RS-5 light source from Gamma Scientific corporation.Lenses 657 held withineyeglasses 658 are positioned to face the light source. Aserial interface 653 is connected betweencomputer 651 andeyeglasses 658 for reporting photovoltages measured by the light sensor of the eyeglasses. The light source may be moved laterally so that the field ofview 655 of the light sensor on the eyeglasses may be determined. -
FIG. 12B shows a second calibration configuration 660 suitable for calibrating the transmissivity ofeyeglasses 658.Computer 651 has aninterface 654 to calibratedlight source 652, theinterface 654 allowing for automatic programming of the luminant intensity oflight source 652. Thelenses 657 held withineyeglasses 658 are positioned to face the light source. Aserial interface 653 is connected betweencomputer 651 and the eyeglasses for programming the duty cycle of the PWM drive voltage forlenses 657 therein. A calibratedphotodetector 665 is placed behind the eyeglass lens facing the calibratedlight source 652 and made to detect light from the light source as transmitted through the lens, calibratedphotodetector 665 connected tocomputer 651 by acomputer interface 666. The computer has a program that can vary the duty cycle oflenses 657 and for each duty cycle, download the corresponding measured light intensity from calibratedphotodetector 665. The values can be stored according to patient and product number for future reference. -
FIG. 13 is a flowchart of acalibration method 600 used in conjunction with the first and second calibration configurations. The method begins in thestep 601 wherein the PC calibration program is made to run oncomputer 651. The eyeglasses are also connected byinterface 653 tocomputer 651 instep 602, the eyeglasses having theelectronic circuit 260 therein. A calibration program is downloaded to the memory of the eyeglasses instep 604 using theinterface 653. The calibration program contains program instructions to be executed by themicroprocessor 268 to measure and communicate the photovoltage V from the eyeglasses light sensor. The calibration program also contains program instructions for accepting instructions viainterface 653 to set the duty cycle of PWM signal that is drivinglenses 657. - In
step 606,computer 651 setslight source 652 to a first predetermined intensity L and then instep 608microprocessor 268 measures first photovoltage V corresponding to the light detected by the eyeglasses.Steps loop 609 for at least second and third predetermined intensities and for second and third measured voltages. Instep 610 the slope of measured voltage V versus light intensity L is determined and stored as the eyeglasseslight sensor response 613. - Step 611 is performed next, wherein the
light source 652 is moved horizontally to determine the horizontal field of view of the eyeglasses light sensor and then moved vertically to determine the vertical field of view of the eyeglasses light sensor. While movinglight source 652, the photovoltage is measured and reported by the microprocessor and displayed on the computer. Typically, the position of the light source and the measured photovoltage is recorded by hand. The photovoltage falls off with position determining the edges of the field of view which is calculated according to the geometry of the apparatus. The field ofview 615 is stored incomputer 651 for later download to the eyeglasses. - After the light sensor is calibrated in
steps 606 through 611, the LCD lens is calibrated insteps 612 through 618. Beginning withstep 612,computer 651 sets thelight source 652 to a predetermined instensity L_i.Computer 651 then instep 614 sends the eyeglasses a set of duty cycles between 0% and 50%, preferably in steps of 2%. Instep 616, the computer measures the transmitted light through the lens.Steps loop 621. Transmitted light level L_t is measured by calibratedphotodetector 665, the measured values of L_t being communicated tocomputer 651. Instep 618 the LCD response curve similar to thecurve 501 ofFIG. 10 is determined for duty cycle versus transmissivity T, wherein T=L_t/L_i and fit coefficients for three regions of operation are determined forlinear functions linear function LCD response coefficients 617. The method does not preclude using more than three regions and more than three linear functions, nor does it preclude fitting a more complex function to the LCD response curve. - In another embodiment, the set of data points (Tk, Dk), measured in
loop 621 for a set of k duty cycles, are stored in the eyeglasses as an LCD response lookup table. To utilize the lookup table, theDutyCycle subroutine 325 is replaced with a different subroutine that performs the following steps to look up a duty cycle D0 for a given input transmissivity T0: in the first step, looking up two T values in the lookup table nearest T0 in value, T1 and T2; then, looking up the duty cycles D1 and D2 corresponding to T1 and T2; interpolating between (T1, D1) and (T2, D2) to compute D0; and returning D0 to the calling program. - In
step 620 the calibration process concludes whenLCD response coefficients 617, field ofview 615 andsensor response 613 are stored into anoperational program 619 which is further downloaded into eyeglasses memory for normal operation.Operational program 619 is similar toeyeglasses program 300 described previously. - As shown in
FIG. 14 ,physicians program 700 is conceived for use alongsideeyeglasses 10, the physicians program being operated on a personal computer normally situated in the physician's office in proximity to the patient for which the eyeglasses are intended for use. The physicians program is initiated instep 702 which causes a Microsoft Windows program to operate instep 704. The Windows program checks that the eyeglasses are connected to the computer instep 708 and that the eyeglasses are running a valid operational program; if not, then a warning that the eyeglasses are not ready is displayed by the computer instep 709. If the eyeglasses are connected to the computer and running a valid operational program, then a patient data screen is displayed instep 710. The physician then enters the patient data instep 714 and a desired lower light level L_min in units of cd/m2 instep 716. Thephysicians program 700 then checks if the light level is in the proper range, which is typically [0.1, 500] cd/m2. If no value is entered, a default value of 15 cd/m2 is chosen in the preferred embodiment. If outside the proper range, then a prompt to reenter the data is displayed on the computer instep 719. If the light level is in range, then the patient data and the light level is downloaded to the eyeglasses instep 720 and a message to the effect that the eyeglasses have been successfully programmed is displayed instep 722. The physician's program ends atstep 725 by exiting the program. - In
step 714, L_min is preferably the light level where the eyeglasses are set to achieve maximum transmissivity. Alternate embodiments are conceived for capturing different patient requirements. The physician's method may also be applied to eyeglasses with analog electronics wherein L_min is set by a rotatable screw control. -
FIG. 15 shows a typical physician's computer form display associated to the physician'sprogram 700, the display fields being apatient name 750,patient street address 751,patient city address 752,patient state 753,patient zip code 754, date ofservice 755 and theminimum light level 760. -
Eye glasses 10 along withcircuit 260 are considerably flexible in application due to programmability. Other embodiments may be conceived to take advantage of the programmability as a result. For example, different battery types may be accommodated by extending the program of interruptprocedure 302 to enter a battery type and then the corresponding battery voltage taken into account in computing duty cycles. - The exemplary embodiments described are not intended to limit the present invention application to ARMD treatment, but to serve as a concrete description and useful exemplary application of the inventive concept herein.
Claims (1)
1. Eye glasses having adjustable variable transmissivity for controlling the amount of light on at least one eye positioned behind said glasses comprising:
A frame capable of holding lenses and having earpieces rotatably attached to either side;
Two lenses fixed into the frame and having transmissivity controllable by a lens voltage signal connected to the lenses;
A photoelectric light sensor integrated into the frame so as to sense ambient light in a field of view to the front of the eye glasses and producing a measured photocurrent in response to the ambient light,
a light plug having at least two apertures positionally arranged to define the field of view for the photoelectric light sensor in a horizontal plane and in a vertical plane, the horizontal plane being the plane containing the center points of the two lenses and the vertical plane being a plane which is perpendicular to the horizontal plane, all points in the vertical plane being equidistant from the center points of the two lenses;
An electronic circuit mechanically attached to the frame and electrically attached to the photoelectric light sensor and the lenses, the electronic circuit capable of converting the measured photocurrent to a PWM signal with a duty cycle proportional to the measured photocurrent, the electronic circuit further converting the PWM signal to the lens voltage signal;
control means for controlling transmissivity response of the lens, the control means being mechanically attached to the frame and electrically attached to the electronic circuit;
a set of batteries for powering the electronic circuit and the lenses, the set of batteries being held in a battery compartment made into the frame;
an on/off switch connecting the set of batteries to the electronic circuit, the on/off switch being integrated into the frame;
the lenses each comprising a first glass substrate, a second glass substrate, and a liquid crystal material sealed therebetween; wherein the first glass substrate comprises a first surface coated with an input polarizing film, a second surface coated with a first metal layer of Indium Tin Oxide, and a first alignment layer coated over the first metal layer; wherein the second glass substrate comprises a third surface coated with an output polarizing film, a fourth surface coated with a second metal layer of Indium Tin Oxide, and a second alignment layer coated over the second metal layer; wherein the first glass substrate and the second glass substrate are oriented so that the first alignment layer faces the second alignment layer; and wherein the lens signal voltage is connected between the first metal layer and the second metal layer.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/072,535 US20090213283A1 (en) | 2008-02-27 | 2008-02-27 | Apparatus and method for adjustable variable transmissivity polarized eye glasses |
PCT/US2009/035246 WO2009108753A1 (en) | 2008-02-27 | 2009-02-26 | Apparatus and method for adjustable variable transmissivity polarized eye glasses |
US12/402,422 US8233102B2 (en) | 2008-02-27 | 2009-03-11 | Apparatus and method for adjustable variable transmissivity polarized eyeglasses |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/072,535 US20090213283A1 (en) | 2008-02-27 | 2008-02-27 | Apparatus and method for adjustable variable transmissivity polarized eye glasses |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/402,422 Continuation US8233102B2 (en) | 2008-02-27 | 2009-03-11 | Apparatus and method for adjustable variable transmissivity polarized eyeglasses |
Publications (1)
Publication Number | Publication Date |
---|---|
US20090213283A1 true US20090213283A1 (en) | 2009-08-27 |
Family
ID=40635801
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/072,535 Abandoned US20090213283A1 (en) | 2008-02-27 | 2008-02-27 | Apparatus and method for adjustable variable transmissivity polarized eye glasses |
US12/402,422 Active 2029-07-14 US8233102B2 (en) | 2008-02-27 | 2009-03-11 | Apparatus and method for adjustable variable transmissivity polarized eyeglasses |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/402,422 Active 2029-07-14 US8233102B2 (en) | 2008-02-27 | 2009-03-11 | Apparatus and method for adjustable variable transmissivity polarized eyeglasses |
Country Status (2)
Country | Link |
---|---|
US (2) | US20090213283A1 (en) |
WO (1) | WO2009108753A1 (en) |
Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090213282A1 (en) * | 2008-02-27 | 2009-08-27 | Rgb Optics Llc | Apparatus and method for adjustable variable transmissivity polarized eyeglasses |
US20090290738A1 (en) * | 2008-05-23 | 2009-11-26 | Zounds, Inc. | Light powered hearing aid |
CN104350414A (en) * | 2012-03-26 | 2015-02-11 | 法雷奥照明公司 | Adaptive spectacles for motor vehicle drivers or passengers |
US20150092083A1 (en) * | 2013-09-30 | 2015-04-02 | Nghia Trong Lam | Active Shielding Against Intense Illumination (ASAII) System for Direct Viewing |
EP3006993A1 (en) | 2014-10-06 | 2016-04-13 | design GmbH castelberg | Electro-optical glare minimising glass |
US20160144582A1 (en) * | 2012-11-14 | 2016-05-26 | Ehs Lens Philippines, Inc. | Method of manufacturing polarizing plastic lens |
CN107111165A (en) * | 2014-12-30 | 2017-08-29 | 埃西勒国际通用光学公司 | The method for controlling active filtering apparatus |
US20180009453A1 (en) * | 2015-01-12 | 2018-01-11 | Siemens Aktiengesellschaft | Light Signal |
US9897809B2 (en) | 2013-09-26 | 2018-02-20 | Valeo Vision | Data-display glasses comprising an anti-glare screen |
US9915831B2 (en) | 2013-09-26 | 2018-03-13 | Valeo Vision | Adaptive optical filter for spectacle lenses |
US10073275B2 (en) | 2013-09-26 | 2018-09-11 | Valeo Vision | Anti-glare 3D glasses |
US10195982B2 (en) | 2013-09-26 | 2019-02-05 | Valeo Vision | Driving assistance method and device |
US10254545B2 (en) | 2013-09-26 | 2019-04-09 | Valeo Vision | Data-display glasses comprising an anti-glare screen |
WO2020056251A1 (en) * | 2018-09-13 | 2020-03-19 | Wicue, Inc. | Dimmable eyewear |
EP3839612A1 (en) * | 2019-12-20 | 2021-06-23 | Essilor International | Ophthalmic device having adjustable filtering properties |
US11213429B1 (en) * | 2021-02-05 | 2022-01-04 | Shenzhen Wicue Optoelectronics Co. LTD. | Dual lens dimmable eyewear |
US20230086352A1 (en) * | 2020-08-19 | 2023-03-23 | E-Vision Smart Optics, Inc. | Electro-Active Sporting Glasses |
Families Citing this family (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ES2334960A1 (en) * | 2008-06-11 | 2010-03-17 | Universidad De Valladolid | Device for assisting and protecting vision |
US8922723B2 (en) * | 2010-06-30 | 2014-12-30 | Panasonic Corporation | Optical device |
US20120050856A1 (en) * | 2010-09-01 | 2012-03-01 | Sony Corporation | Apparatus and process for stereoscopic vision |
KR101221426B1 (en) * | 2010-10-22 | 2013-01-11 | 주식회사 오토스윙 | Optical properties control system for sunglass or goggle and sunglass and goggle with the same |
KR20120078310A (en) * | 2010-12-31 | 2012-07-10 | 삼성전자주식회사 | Glasses for three dimension display apparatus |
CH704413A2 (en) | 2011-01-31 | 2012-07-31 | Eyerex Ag | An electro-optical sunglasses and method for making same. |
US9046730B2 (en) * | 2011-04-21 | 2015-06-02 | Kent Optronics, Inc. | Displays and sensors integrated with multi-state cholesteric liquid crystal devices |
EP2839338B1 (en) | 2012-04-18 | 2018-01-10 | Switch Materials, Inc. | System and method for controlling an optical filter assembly |
AU2012395866B2 (en) | 2012-12-03 | 2017-03-16 | Colorlink Japan, Ltd. | Optical device |
WO2014087448A1 (en) * | 2012-12-03 | 2014-06-12 | カラーリンク・ジャパン 株式会社 | Optical device |
CN105164576B (en) * | 2013-04-25 | 2019-07-05 | 依视路国际公司 | The method that the wear-type electro-optic device for adapting to wearer is controlled |
FR3011092B1 (en) * | 2013-09-26 | 2016-12-23 | Valeo Vision | DATA DISPLAY LENSES HAVING AN ANTI-GLARE SCREEN |
US9933634B2 (en) * | 2014-06-13 | 2018-04-03 | Verily Life Sciences Llc | Apparatus, system and method for gaze tracking based on photodetection by an eye-mountable device |
GB2533546A (en) * | 2014-10-16 | 2016-06-29 | Esg Group Ltd | A controller device |
US10539812B2 (en) * | 2015-05-01 | 2020-01-21 | Switch Materials Inc. | Eyewear control system and method, and an eyewear device |
USD834086S1 (en) | 2015-06-16 | 2018-11-20 | Ashwin-Ushas Corporation, Inc. | Electrochromic eyewear |
US9632059B2 (en) | 2015-09-03 | 2017-04-25 | Ashwin-Ushas Corporation, Inc. | Potentiostat/galvanostat with digital interface |
US9482880B1 (en) * | 2015-09-15 | 2016-11-01 | Ashwin-Ushas Corporation, Inc. | Electrochromic eyewear |
US9945045B2 (en) | 2015-12-02 | 2018-04-17 | Ashwin-Ushas Corporation, Inc. | Electrochemical deposition apparatus and methods of using the same |
US10061112B1 (en) | 2016-02-03 | 2018-08-28 | Opti-Logic Corporation | Optical accessory projection system |
CN108020931A (en) * | 2016-10-28 | 2018-05-11 | 北京嘀嘀无限科技发展有限公司 | Drive assist system |
EP3618746A4 (en) | 2017-05-04 | 2021-06-16 | Junebrain, Inc. | Brain monitoring system |
US11513369B2 (en) | 2017-05-10 | 2022-11-29 | Jing Jin | Magnetic eyeglasses attachment comprising decorative elements and/or functional elements including lenses and methods of producing same |
US11333810B2 (en) | 2017-08-25 | 2022-05-17 | Solutia Canada Inc. | System of networked controllers, and method of operating a system of networked controllers |
CN113690088B (en) * | 2021-08-26 | 2023-12-22 | 歌尔科技有限公司 | Switch assembly, glasses leg and glasses |
Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4181408A (en) * | 1977-12-05 | 1980-01-01 | Senders John W | Vision compensation |
US4279474A (en) * | 1980-03-25 | 1981-07-21 | Belgorod Barry M | Spectacle lens having continuously variable controlled density and fast response time |
US4919520A (en) * | 1984-08-31 | 1990-04-24 | Olympus Optical Company | Liquid crystal eyeglass |
US4968127A (en) * | 1988-11-23 | 1990-11-06 | Russell James P | Controllable, variable transmissivity eyewear |
US5074647A (en) * | 1989-12-07 | 1991-12-24 | Optical Shields, Inc. | Liquid crystal lens assembly for eye protection |
US5184156A (en) * | 1991-11-12 | 1993-02-02 | Reliant Laser Corporation | Glasses with color-switchable, multi-layered lenses |
US5327269A (en) * | 1992-05-13 | 1994-07-05 | Standish Industries, Inc. | Fast switching 270° twisted nematic liquid crystal device and eyewear incorporating the device |
US5510609A (en) * | 1993-09-13 | 1996-04-23 | Optrel Ag | Electrically controllable optical filter element |
US5654786A (en) * | 1996-01-11 | 1997-08-05 | Robert C. Burlingame | Optical lens structure and control system for maintaining a selected constant level of transmitted light at a wearer's eyes |
US5841507A (en) * | 1995-06-07 | 1998-11-24 | Barnes; Elwood E. | Light intensity reduction apparatus and method |
US5959705A (en) * | 1996-03-15 | 1999-09-28 | Osd Envizion, Inc. | Welding lens with integrated display, switching mechanism and method |
US6067129A (en) * | 1996-03-15 | 2000-05-23 | Osd Envizion, Inc. | Welding lens with integrated display and method |
US6491391B1 (en) * | 1999-07-02 | 2002-12-10 | E-Vision Llc | System, apparatus, and method for reducing birefringence |
US6884987B2 (en) * | 2001-05-05 | 2005-04-26 | Jackson Products, Inc. | Microprocessor based automatically dimmable eye protection device with interruption prevention |
US6897917B2 (en) * | 2003-02-21 | 2005-05-24 | Spectraswitch, Inc. | Liquid crystal variable optical attenuator |
US20090066863A1 (en) * | 2007-09-07 | 2009-03-12 | Real D | System and eyewear for viewing stereoscopic imagery |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5110885A (en) | 1974-07-04 | 1976-01-28 | Bridgestone Tire Co Ltd | Gomusoseibutsuto kinzokuzairyotokaranarufukugotai oyobi sonoseizohoho |
JPS55100527A (en) | 1979-01-24 | 1980-07-31 | Canon Inc | Spectacles |
FR2530039A1 (en) * | 1982-07-06 | 1984-01-13 | Cuvelier Antoine | Safety (protective) glasses having automatically adjustable transmission using liquid crystals |
JPS61177434A (en) | 1985-02-02 | 1986-08-09 | Olympus Optical Co Ltd | Liquid crystal spectacles device |
JPH01150114A (en) | 1987-12-08 | 1989-06-13 | Seiko Epson Corp | Liquid crystal sunglass with solar battery |
JP2743464B2 (en) | 1988-05-11 | 1998-04-22 | セイコーエプソン株式会社 | Electronic sunglasses |
JPH02230116A (en) | 1988-05-17 | 1990-09-12 | Baiotoron:Kk | Dimming spectacles |
JPH03163413A (en) | 1989-11-21 | 1991-07-15 | Seiko Epson Corp | Electronic sunglasses |
GB9211427D0 (en) * | 1992-05-29 | 1992-07-15 | Crystalens Ltd | Liquid crystal lens circuit |
JPH0643406A (en) | 1993-03-29 | 1994-02-18 | Seiko Epson Corp | Electronic sunglasses |
JP2626455B2 (en) | 1993-03-29 | 1997-07-02 | セイコーエプソン株式会社 | Electronic sunglasses |
JPH08136883A (en) | 1994-11-04 | 1996-05-31 | Wako Inter:Kk | Electronic sunglasses |
JPH09179075A (en) | 1995-12-22 | 1997-07-11 | Fujitsu Kiden Ltd | Light control eyeglasses |
US20090213283A1 (en) | 2008-02-27 | 2009-08-27 | Burlingame Robert G | Apparatus and method for adjustable variable transmissivity polarized eye glasses |
-
2008
- 2008-02-27 US US12/072,535 patent/US20090213283A1/en not_active Abandoned
-
2009
- 2009-02-26 WO PCT/US2009/035246 patent/WO2009108753A1/en active Application Filing
- 2009-03-11 US US12/402,422 patent/US8233102B2/en active Active
Patent Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4181408A (en) * | 1977-12-05 | 1980-01-01 | Senders John W | Vision compensation |
US4279474A (en) * | 1980-03-25 | 1981-07-21 | Belgorod Barry M | Spectacle lens having continuously variable controlled density and fast response time |
US4919520A (en) * | 1984-08-31 | 1990-04-24 | Olympus Optical Company | Liquid crystal eyeglass |
US4968127A (en) * | 1988-11-23 | 1990-11-06 | Russell James P | Controllable, variable transmissivity eyewear |
US5074647A (en) * | 1989-12-07 | 1991-12-24 | Optical Shields, Inc. | Liquid crystal lens assembly for eye protection |
US5184156A (en) * | 1991-11-12 | 1993-02-02 | Reliant Laser Corporation | Glasses with color-switchable, multi-layered lenses |
US5327269A (en) * | 1992-05-13 | 1994-07-05 | Standish Industries, Inc. | Fast switching 270° twisted nematic liquid crystal device and eyewear incorporating the device |
US5510609A (en) * | 1993-09-13 | 1996-04-23 | Optrel Ag | Electrically controllable optical filter element |
US5841507A (en) * | 1995-06-07 | 1998-11-24 | Barnes; Elwood E. | Light intensity reduction apparatus and method |
US5654786A (en) * | 1996-01-11 | 1997-08-05 | Robert C. Burlingame | Optical lens structure and control system for maintaining a selected constant level of transmitted light at a wearer's eyes |
US5959705A (en) * | 1996-03-15 | 1999-09-28 | Osd Envizion, Inc. | Welding lens with integrated display, switching mechanism and method |
US6067129A (en) * | 1996-03-15 | 2000-05-23 | Osd Envizion, Inc. | Welding lens with integrated display and method |
US6491391B1 (en) * | 1999-07-02 | 2002-12-10 | E-Vision Llc | System, apparatus, and method for reducing birefringence |
US6884987B2 (en) * | 2001-05-05 | 2005-04-26 | Jackson Products, Inc. | Microprocessor based automatically dimmable eye protection device with interruption prevention |
US6897917B2 (en) * | 2003-02-21 | 2005-05-24 | Spectraswitch, Inc. | Liquid crystal variable optical attenuator |
US20090066863A1 (en) * | 2007-09-07 | 2009-03-12 | Real D | System and eyewear for viewing stereoscopic imagery |
Cited By (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8233102B2 (en) | 2008-02-27 | 2012-07-31 | Rgb Optics, Llc | Apparatus and method for adjustable variable transmissivity polarized eyeglasses |
US20090213282A1 (en) * | 2008-02-27 | 2009-08-27 | Rgb Optics Llc | Apparatus and method for adjustable variable transmissivity polarized eyeglasses |
US20090290738A1 (en) * | 2008-05-23 | 2009-11-26 | Zounds, Inc. | Light powered hearing aid |
US8712085B2 (en) * | 2008-05-23 | 2014-04-29 | Zounds Hearing, Inc. | Light powered hearing aid |
CN104350414A (en) * | 2012-03-26 | 2015-02-11 | 法雷奥照明公司 | Adaptive spectacles for motor vehicle drivers or passengers |
US9869886B2 (en) | 2012-03-26 | 2018-01-16 | Valeo Vision | Adaptive spectacles for motor vehicle drivers or passengers |
US20160144582A1 (en) * | 2012-11-14 | 2016-05-26 | Ehs Lens Philippines, Inc. | Method of manufacturing polarizing plastic lens |
US10363712B2 (en) * | 2012-11-14 | 2019-07-30 | Ehs Lens Philippines, Inc. | Method of manufacturing polarizing plastic lens |
US10254545B2 (en) | 2013-09-26 | 2019-04-09 | Valeo Vision | Data-display glasses comprising an anti-glare screen |
US10195982B2 (en) | 2013-09-26 | 2019-02-05 | Valeo Vision | Driving assistance method and device |
US10073275B2 (en) | 2013-09-26 | 2018-09-11 | Valeo Vision | Anti-glare 3D glasses |
US9915831B2 (en) | 2013-09-26 | 2018-03-13 | Valeo Vision | Adaptive optical filter for spectacle lenses |
US9897809B2 (en) | 2013-09-26 | 2018-02-20 | Valeo Vision | Data-display glasses comprising an anti-glare screen |
US9323053B2 (en) * | 2013-09-30 | 2016-04-26 | Nghia Trong Lam | Active shielding against intense illumination (ASAII) system for direct viewing |
US20150092083A1 (en) * | 2013-09-30 | 2015-04-02 | Nghia Trong Lam | Active Shielding Against Intense Illumination (ASAII) System for Direct Viewing |
EP3006993A1 (en) | 2014-10-06 | 2016-04-13 | design GmbH castelberg | Electro-optical glare minimising glass |
CN107111165A (en) * | 2014-12-30 | 2017-08-29 | 埃西勒国际通用光学公司 | The method for controlling active filtering apparatus |
US20180009453A1 (en) * | 2015-01-12 | 2018-01-11 | Siemens Aktiengesellschaft | Light Signal |
US10525992B2 (en) * | 2015-01-12 | 2020-01-07 | Siemens Mobility GmbH | Light signal |
US11016312B2 (en) | 2018-09-13 | 2021-05-25 | Wicue, Inc. | Dimmable eyewear |
WO2020056251A1 (en) * | 2018-09-13 | 2020-03-19 | Wicue, Inc. | Dimmable eyewear |
JP2021536598A (en) * | 2018-09-13 | 2021-12-27 | ウィキュー、インコーポレーテッド | Dimmable eyewear |
JP7464045B2 (en) | 2018-09-13 | 2024-04-09 | ウィキュー ユーエスエー インコーポレーテッド | Photochromic Eyewear |
EP3839612A1 (en) * | 2019-12-20 | 2021-06-23 | Essilor International | Ophthalmic device having adjustable filtering properties |
WO2021122938A1 (en) * | 2019-12-20 | 2021-06-24 | Essilor International | Ophthalmic device having adjustable filtering properties |
CN114868073A (en) * | 2019-12-20 | 2022-08-05 | 依视路国际公司 | Ophthalmic device with adjustable filtering characteristics |
US20230086352A1 (en) * | 2020-08-19 | 2023-03-23 | E-Vision Smart Optics, Inc. | Electro-Active Sporting Glasses |
US11213429B1 (en) * | 2021-02-05 | 2022-01-04 | Shenzhen Wicue Optoelectronics Co. LTD. | Dual lens dimmable eyewear |
Also Published As
Publication number | Publication date |
---|---|
US20090213282A1 (en) | 2009-08-27 |
US8233102B2 (en) | 2012-07-31 |
WO2009108753A1 (en) | 2009-09-03 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8233102B2 (en) | Apparatus and method for adjustable variable transmissivity polarized eyeglasses | |
US5654786A (en) | Optical lens structure and control system for maintaining a selected constant level of transmitted light at a wearer's eyes | |
CA1152367A (en) | Spectacle lens having continuously variable controlled density and fast response time | |
US5552841A (en) | Liquid crystal eyeglasses | |
US4968127A (en) | Controllable, variable transmissivity eyewear | |
US5182585A (en) | Eyeglasses with controllable refracting power | |
CN107111145B (en) | Head-mounted display device and display method | |
JP7034071B2 (en) | Variable transmittance Control based on the range of transmittance of the lens | |
US20090103044A1 (en) | Spectacle frame bridge housing electronics for electro-active spectacle lenses | |
US10539812B2 (en) | Eyewear control system and method, and an eyewear device | |
WO1992010130A1 (en) | Method and apparatus for controlling perceived brightness using a time varying shutter | |
CN107767830B (en) | Display device and display driving method | |
US8474976B2 (en) | Automatic accommodative spectacles using sensors and focusing elements | |
CN210348106U (en) | Intelligent glasses | |
JP2016139116A (en) | Head-mounted display device and display method | |
JP2007304587A (en) | Spectacle frame bridge housing electronic apparatus for electro-active spectacle lenses | |
CN101592793B (en) | Full-automatic angle shading eyeglasses | |
US11684538B2 (en) | Vision training device with refractive index-adjustable lens | |
JPH0937196A (en) | Liquid crystal display device | |
CN110658639A (en) | Detachable light-adjusting glasses | |
JP2009237226A (en) | Electronic eyeglasses | |
JPH02230116A (en) | Dimming spectacles | |
CN211014892U (en) | Intelligent glasses with adjustable light transmittance | |
CN218181250U (en) | Lens and myopia glasses with adjustable brightness | |
US10908435B2 (en) | Automatically photosensitive sunglasses with low power consumption |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: BURLINGAME, ROBERT G., TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BURLINGAME, ROBERT G.;BYLANDER, ERNEST G.;HINES, ROBIN;AND OTHERS;REEL/FRAME:022314/0984;SIGNING DATES FROM 20080118 TO 20080522 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |