CA2178848A1 - Color wheel with plastic film filters - Google Patents
Color wheel with plastic film filtersInfo
- Publication number
- CA2178848A1 CA2178848A1 CA002178848A CA2178848A CA2178848A1 CA 2178848 A1 CA2178848 A1 CA 2178848A1 CA 002178848 A CA002178848 A CA 002178848A CA 2178848 A CA2178848 A CA 2178848A CA 2178848 A1 CA2178848 A1 CA 2178848A1
- Authority
- CA
- Canada
- Prior art keywords
- color wheel
- hub
- filter
- color
- piece
- 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
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3102—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators
- H04N9/3111—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators for displaying the colours sequentially, e.g. by using sequentially activated light sources
- H04N9/3114—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators for displaying the colours sequentially, e.g. by using sequentially activated light sources by using a sequential colour filter producing one colour at a time
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/007—Optical devices or arrangements for the control of light using movable or deformable optical elements the movable or deformable optical element controlling the colour, i.e. a spectral characteristic, of the light
- G02B26/008—Optical devices or arrangements for the control of light using movable or deformable optical elements the movable or deformable optical element controlling the colour, i.e. a spectral characteristic, of the light in the form of devices for effecting sequential colour changes, e.g. colour wheels
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
- G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
- G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD
- G02B26/0841—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD the reflecting element being moved or deformed by electrostatic means
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/30—Picture reproducers using solid-state colour display devices
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
- G02B7/006—Filter holders
Abstract
A color wheel (15) for use in a display system (10).
The color wheel (15) is comprised of a rigid hub (23) and an outer perimeter of color filter segments (21), which are made from a thin plastic material.
The color wheel (15) is comprised of a rigid hub (23) and an outer perimeter of color filter segments (21), which are made from a thin plastic material.
Description
~Y Z0'96 17:3Z FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.02/20 A1-L~ ;Y ~ S DOCRET PATENT APPLICATION
-- T~-18888 (32350-1232) COLOR WHEEL WITH PLASTIC FILM FILTERS
TECHNICAL FIELD OF T~E INVENTION
This invent ion relates to i~nage di~iplay systenls, and more particularly to digital image display systems ~hat use a color wheel.
AUSOI ~1i.17 1 ~RY 20'96 17:32 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.03/20 A1-L~N~r~S DOCKET PATENT APPLICATION
_ TI-18888 BACKGROUND OF THE lNV~N'llON
Image display systems based on ~pacial light modulators ~SLMs) are an alternative to i~age display systems based on cathode ray tubes (CRTs). SLM systems s provide high resolution without the bulk of CRT systems Digital micro-mirror devices (DMDs) are one type of SLM, and may be used for either direct view or for projection displays. A DMD has an array of hundreds or thousands of tiny tilting mirrors, each of which provides light for one pixel of an image. To permit the mirrors co tilt, each mirror is attached to one or more hinges mounted on support posts, and spaced ~y means of a fluidic (air or liquid) gap o~er underlying control circuitry. The control circuitry provides electrostatic forces, which cause each mirror to selectively tilt. For display applications, image data i~ loaded to memory cells of the DMD and in accordance with ~his data, mirrors are tilted ~o as ~o either reflec~ light to, or de~lect light from, the entrance pupil of a projection lens and then to an image plane.
One approach ~o providing color images in an SLM
display sy~tem is referred to as "sequential color~.. All plxels of a frame of the image are sequentially addressed with different colors. For example, ~each pixel might ha~e a red, a green, and a ~lue ~alue. Then, during each frame period, the pixels of that frame are addressed with their red, green, then blue data, alternatingly A color wheel having three segments of these same colors is synchronized to ~he data so that as the data for each color is displayed by the SLM, the light incident on the SLM is ~ ered by the color wheel. For scandard display rates, such as the 30 frame per second NTSC rate, the eye perceives the image as having the proper color.
A ~JSO ~ l 7 1 ~RY 20'96 17:32 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.04/20 Al-luKh~y'S DOCKET PATENT APPLICATION
-- T~-18888 (32350-1232) COLOR WHEEL WITH PLASTIC FILM FILTERS
TECHNICAL FIELD OF T~E INVENTION
This invent ion relates to i~nage di~iplay systenls, and more particularly to digital image display systems ~hat use a color wheel.
AUSOI ~1i.17 1 ~RY 20'96 17:32 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.03/20 A1-L~N~r~S DOCKET PATENT APPLICATION
_ TI-18888 BACKGROUND OF THE lNV~N'llON
Image display systems based on ~pacial light modulators ~SLMs) are an alternative to i~age display systems based on cathode ray tubes (CRTs). SLM systems s provide high resolution without the bulk of CRT systems Digital micro-mirror devices (DMDs) are one type of SLM, and may be used for either direct view or for projection displays. A DMD has an array of hundreds or thousands of tiny tilting mirrors, each of which provides light for one pixel of an image. To permit the mirrors co tilt, each mirror is attached to one or more hinges mounted on support posts, and spaced ~y means of a fluidic (air or liquid) gap o~er underlying control circuitry. The control circuitry provides electrostatic forces, which cause each mirror to selectively tilt. For display applications, image data i~ loaded to memory cells of the DMD and in accordance with ~his data, mirrors are tilted ~o as ~o either reflec~ light to, or de~lect light from, the entrance pupil of a projection lens and then to an image plane.
One approach ~o providing color images in an SLM
display sy~tem is referred to as "sequential color~.. All plxels of a frame of the image are sequentially addressed with different colors. For example, ~each pixel might ha~e a red, a green, and a ~lue ~alue. Then, during each frame period, the pixels of that frame are addressed with their red, green, then blue data, alternatingly A color wheel having three segments of these same colors is synchronized to ~he data so that as the data for each color is displayed by the SLM, the light incident on the SLM is ~ ered by the color wheel. For scandard display rates, such as the 30 frame per second NTSC rate, the eye perceives the image as having the proper color.
A ~JSO ~ l 7 1 ~RY 20'96 17:32 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.04/20 Al-luKh~y'S DOCKET PATENT APPLICATION
Existing color wheels are comprised of gla s dichroic filters arranged around a hub. The~e color wheels are difficult to manufacture and require a~
expensive coating process.
AIJ~UI~ il7 1 MRY 20'96 17:3Z FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.05/20 AI-lOR~Y'S DOCKET PATE~T APPLICATION
` 4 21 78848 SUMMARY OF THE I~V~N 1 LON
One aspect of the in~ention is a color wheel for a display ~yst~m. The color wheel is essentially a rigid hub with a ~hin pla~ic rim of fil~er material. In one embodiment, the hub has a fron~ piece and a back piece for att~chm~nt together to form a generally circular hu~
This hub is made from a rigid material, such as plastic.
A num~er of color filter segments are also ~ade from a plastic material, but may be thin and flexible. These filter segments are substantially pie-shaped, 6uch that a circular edge of each filter segment extends from the perimeter of the hub, with ~he opposing edge o~ the filter segment being secured between the front piece and the back piece of said hub.
An advantage of the inven~ion is that i~ is a low cost color wheel, rp~rared ~o previously used dichroic glass color wheels. It is ~.e~ble to mass production and may be made entirely fro~ plastic materials. The color wheel~is lightweight, and less prone to vibra~ion.
I~s low inertia permits faster spin-up times during operation. In embo~im~nts having a two-piece hub, built-in clamping features can be provided for attachment Qf the color wheel to the chaft of the color wheel mo~or.
AUSOI ~17 1 MRY 20'96 17:32 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.06/20 A~1~K~JS DOCKET PATENT APPLICATION
TI-18a88 5 21 78~48 BRI~F DESCRIPTION OF THE DRAW~NGS
FIGUR~ 1 is a block diagram of a display system ha~ing a color wheel configured and operated in accordance with the invention.
FIGURE 2 is a front view of a color wheel in accordance with the invention.
FIGURE 3 is a side ~iew of a color wheel in accordance with the in~ention FIGU~E 4 is an exploded side view of the color wheel, illustrating ~elf-a~taching mean~ for securing the two pieces of the hub together.
FIGURE 5 is a front view of an alternative embodiment of the color wheel, which has a single-piece fil~er AUS01-~617 1 ~RY 20'96 17:32 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.07/20 All~KN~'S DOCKET PATE~T APPLICATION
_ TI-18888 DETAILED DESCRIPTIO~ OF THE lNv~llON
Displav System O~erview The following description is in terms of a display system that displays image~ generated by an SLM or other pixel array display device. The ~erm ~pixel array display device~ is used in a broad sense to include any type of array that generates a display using individually addressed pixels. Thus, ~or example, the display de~ice migh~ be a liquid crystal array. However, the in~ention is not limited to such de~ices, and could ~e used with any di~play system chat uses a color wheel for sequential color displays. For example, the data described herein could be converted to an analog signal for use by a white light CRT whose images are ~iltered by a color wheel.
FIGURE 1 is a block diagram of a typical SLM-based image display system 10 that u~es a color wheel 15 in accordance with the in~ention.
In the example of FIGURE 1, color wheel 15 has three filter segments, one red, one green, one blue. However, ocher colors could be used, and fewer or more than three colors could be used. As explained below, the in~en~ion is directed to a color wheel who~e filter segments are made from thin plastic film at the outer circumference of a hub.
The following overview of ~he ~arious components of display syste~ 10 provides details helpful to understanding of the invention. Further details pertaining to a DMD-based image display sys~em with other types of color wheels are set out in U.S. Pacent No.
5,079,S44, entitled "Standard Independent ~igitized ~ideo System"; In U.S. Pacent serial No. 08/1~7,249, entitled "Digital Television Systeml'; and in U.S. Patent Serial No 08~146,385, en~itled ~DMD Display System" Further ,'1, 1)~it~ 1 ~1~6 1 7. 1 ~RY 20'96 17:33 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.08/20 ATTORNEY'S DOCK~T PATENT APPLIC~TIO~
details describing the general operation of color wheels fo~ SLM-based display systems are set out in U.S. Patent No. 5,2~3,385, enti1led "White Light ~nhanced Color Field Seq~ential Projection"; U.S. Patent Serial No.
08~179,028, entitled "Method and ApparatuS for Sequential Color Imaging~; and ~.S. Patent Serial No. 08/339,379, entitled "Digital Motor Controller for Color Wheel".
Each of these patents and patent applica~ions is assigned to Texas Instruments Incorporated, and each is incorporated herein by reference.
Signal interface 11 receives so~e kind of input signal. For purposes of example herein, it will be assumed that the input signal is a st~nd~rd analog video signal having horizontal and vercical synchronization components. However, in other sys~ems, the input signal mighc be graphics data already in digital form.
In the case of a video input signal, interface 11 separates t~e video signal from synchronization and audio signals. It includes an A/D conve~ter and a Y/C
separator, which con~ert the data into pixel data samples and separate the lumjn~nce data from the chro~;n~ce data. The signal could be converted to digital data.
before Y/C conversion or Y/C ~eparation co~ld occur before digitization.
Pixel data processor 12 prepares the data for display, by performing various processing tasks.
Processor 12 includes processing memory for storing pixel data during processing. The tasks performed by processor 13 may include linearization, colorspace conversion, and line generation. Linearization remo~es the effect of gamma correction, which is performed on broadcast si~nals to compensate for che no~-linear operation of CRT
displays. Colorspace conversion converts the data to RGs data. Line generation can be used to convert interlaced ~uso~ 17.~
~Y 20'96 17:33 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES-GRLE P.09/20 AL-1~ S DOCKET PATENT APPLICATIN
fields of data into complete frames by generating new data to fill in odd or e~en lines The order in which these tasks are performed may vary Display memory 13 receives processed pixel data from processor 12. Display memory 13 formats the data, on input or on outpu~, into "bit-plane" ~ormat and deli~ers the bit-planes to SLM 14. The bi~-plane format provides one bit at a time for each pixel of SLM 14 and permits each pixel to ~e turned on or off in accordance with the weight of that ~it. For example, where each pixel is represented by 8 bit~i for each of three colors, there will be 3 x 8 , 24 bit-planes per frame. Bit-planes cont~;n;ng less significant bits will result in shorter display times than the bit-planes containing more significant bits.
In a typical display system 10, memory 13 is a double-buffer memory, which means that it has a capacity for at least tWO display frames. The buffer for one display frame can be read out to SLM 14 while the buffer or another display frame is being written. The two buffers are controlled in a "ping-pong" manner so that data is continuously a~ailable to SLM 14.
SLM 14 may be any type of SLM. For purposes of example, this description is in terms of a display system whose SLM is a digital micro-mirror device (DMD).
However, as stated abo~e, the same concepts apply to display systems that use other types of SLMs or other image generating devices.
Light incident on SLM 14 is provided by a light source 16 and is transmitted through a rotacing color wheel 15. In the system o~ FIGURE 1, SLM l~ is a reflective SLM (a DMD), and the color wheel 15 is used to filter the light before reflection As an alterna~ive, AUli~ 4~617.1 MRY 20196 17: 33 FR TEXRS I NST . LEG~L DEP 14 995 351 1 TO K I RBY, ERDES . G~LE P . 10/20 AL1O~N~;Y ~ S DOCRET PAI~NT AppLIc~TION
the color w~eel 15 could be placed so that light is filtered a~ter being emi~ted or reflected.
As ~xplain~d in the Background, the data for each color are sequenced and the display of the data is s synchronized so that the portion of color wheel 15 through which light is being transmitted to ~LM 14 corresponds to the data being displayed. In the example of this description, each pixel is rep~esented by RGB
data, which means that each pixel has a red value, a O green value, and a blue value. As the values for each color of all pixels in a frame are being displayed, color wheel 15 rotate~ so that the light is transmitted through the corresp~; n~ red, blue or green fileer. For each pixel, the com~ina~ion of these three values is perceived as the desired color.
Color wheel 1~ i~ dri~en by a motor 15a ~ia shaft l5b. Motor l5a includes a controller that control~ the speed and p~ase o~ color wheel 15. For example, the desired speed might be 60 revolutions per second to correspond ~o a 60 frame per second display rate. The phase is set so that the proper filter (red, green, or blue) of color wheel 15 is transmitting light from SLM 14 as the data for that filter is being displayed. To maintain a correct phase relationship between the color wheel 15 and the data being displayed, the color wheel 15 can ~peed up or slow down or the data can be delayed or skipped.
For a DMD-based system, the data delivered ~o sLM 14 is in a special bit-plane format for pulse width modulation. Each red, green, and blue value of a pixel has n bits per ~rame. A pixel value of 0 (black) results in the pixel being off for that color d~ring the f rame.
~or each color, each mirror element of the SLM 14 can be "on" for a dur~tion of anywhere from 1 LSB period to 2n-AUSOI ;~617., MRY 20'96 17:34 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.11/20 ATTORNEY~S DOCRET PATE~T APPLICATION
_ TI-18888 lo 2 1 78848 LSB periods. ~n other words, each color has 2~-1 time slices, duri~g which any pixel can be on for any number of ti~e slices between 0 and 2n-l.
Where a frame o~ data is displayed for a frame period of T seconds, color wheel 15 has a period of revolution of T seconds. If each color were to be displayed for an equal time, the color wheel 15 would have equally sized segmentQ of each color and the data for each color would then be displayed for T/3 seconds.
The LSB period would be the frame time for each color divided by the number of LSB periods for that color.
Master timing unit 18 provides various sys~em control functions. One timing signal provided by master timing unit 18 is a signal defining the display times for each bit weight of the pixel value.
Although not illustrated in FIGURE 1, system 10 also includes a projection lens and ~arious other optical devices for collecting and projecting the image from SLM
14 to the image plane (screen).
FIGUREs 2 and 3 are a front view and a side view, respecti~ely, of color wheel 15 A typical si2e of color wheel 15 is approximately 4 inches in dia~eter for incident light having a spot size of 4 - 6 millimeters.
This size is sufficiently large so as to minimize the time when the incident light coincides with a spoke 24 or other transition beeween filter segments 21 Color wheel 15 is comprised of a rigid two-piece hub 23, which has a front piece 23a and a back piece 23b.
Front p~ece 23a and ~ack piece 23b are attached in a manner that clamps filter segments 21 into place. An example of a suitable material for hub 23 is plastic, which may be easily molded to form pieces 23a and 23b.
In the example of this descr,ption, color wheel 15 ha~ ~hree filter segmen~s 21, one for each of ~hre~
AUs~ 6l7 1 RY 20'96 17:34 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES.GRLE P.12/20 Allu~N~S DOCgET PATENT APPLICATION
~I-18888 primary colors: red, blue and green. However, in other embodiments, there could be more than one segment for each color. There mig~t also be segments for more or for fewer colors, and there might be a clear segment. Each 5 filter ~egment 21 i9 made from a thin plastic ma~erial.
Examples of ~ultable materials are mylar or pol~ester film. The plastic is impregnated wich dye, or otherwise made to crea~e an absorp~ive filter to obtain the desired color. A feature of the invention i9 that filter 0 ~egments 21 need not be rigid and can be made from rela~ively flexible materials.
Each filter segment 21 is substantially pie-shaped, so that its inner area can be clamped within hu~ 23 and i~s circular outer perimeter can excend out from hub 23.
The two pieces 23a and 23b of hub 23 snap or otherwise attach together, thereby "~andwiching" the appropriate portion of filter segments 21.
As illustrated in FIGURE 2, the front piece 23a and back piece of 23b ha~e a spoke 24 at each junction of one filter segment 21 to another. This contemplates that filter ~egments 21 will be comprised of separate pieces.
The spokes 24 join the abutting edges of adjacent filter segments 21 and prevent wind resis~ance at these edges during operation as well as add stiffness eo the fil~er portion of the color wheel 15.
Various mechanical features can ~e easily molded to the inner surfaces of pieces 23a and 2~b so that these pieces can be self-securing when pressed together. For example, as illustrated in FIGUR~ 4, one piece 23a might have a plastic sleeve 41 protruding from its inner surface. The other piece 23b has a corresponding center opening for receiving the sleeve, with the diameter of the opening being of a size that will provide a snug fit of slee~e 41 Sleeve 41 hae a wedge ~la t.ha~ snap~ into AUS01:L1617.1 ~RY 20'96 17:34 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.13/20 Ar-l~N~Y~S DOCXET ~ATENT APPLICATIO~
a wedge-shaped enlargement of the opening in piece 23b.
This permits pieces 23a and 23b to be clamped to shaft l5b without additional parts. Other built-in mechanical feacures can easily be imagined, with interlocking wedges or other features for attaching the hu~ 23 to the color wheel motor shaft l5b. Ex~rinsic fastening means, such as screws, can also be used.
The thickness of filter segments 21 is a balance between ~eing sufficiently thick to provide some stiffness and sufficiently thin so as co minimize loss of light. To some extent, centrifugal force during opera~ion can compensate for lack of stiffneæs. Typical thicknesses of filter segments 21 are ~etween 1 and 2 ~illimeters.
l$ As illustrated in FIGURE 3, hub 23 may be made thicker at its mid-portion where it is attached to the drive shaft of the color wheel motor. This result~ in hub 23 being ~mass loaded'~ around che drive shaft of the color wheel motor and enhances proper balance.
In an alternati~e PmhoA;ment, color wheel 15 could have a hub 23 that is comprised of only one piece 23a.
The filter segments 21 would be attached to one side.of hub 23, around its perimeter, by means such as glue. As discussed above, hu~ 23 may have spokes 24, to which the filter segments 21 would be attached, either to join edges of separate filter segments 21 or to add stiffness ~o the filter portion of the color wheel.
FIGURE S illustrate~ another embodiment of color wheel 15, where all filter segments 21 are made from a single piece of material having differently colored areas, each forming a different fil~er segment 21. The fil~er segments ~1 are ring-shaped, and may be attached between two pieces 23a and 23b of hub 23 or attached to one side of a single-piece hu~ 23~ Tn this case, spokes Ausl)~ 617,1 ~RY 20'96 17:34 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY.ERDES,GRLE P.14/20 ~l'L~ S DOCKET PATENT APPLICATION
24 might not be necessary depending on the stif~ness of the filter matexial.
In operation, color wheel lS is rotated sufficiently fast -~o as to introduce a radial airflow that cools the filter segments 21 from the absorbed radiation. A
rotation speed of approximately 3600 revolutions per minute has been found to be satisfactory.
Other Embo~ nts Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed em~odiments, as well as alternati~e em~odimen~s, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the in~ention.
, AUSOI ~617.1
expensive coating process.
AIJ~UI~ il7 1 MRY 20'96 17:3Z FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.05/20 AI-lOR~Y'S DOCKET PATE~T APPLICATION
` 4 21 78848 SUMMARY OF THE I~V~N 1 LON
One aspect of the in~ention is a color wheel for a display ~yst~m. The color wheel is essentially a rigid hub with a ~hin pla~ic rim of fil~er material. In one embodiment, the hub has a fron~ piece and a back piece for att~chm~nt together to form a generally circular hu~
This hub is made from a rigid material, such as plastic.
A num~er of color filter segments are also ~ade from a plastic material, but may be thin and flexible. These filter segments are substantially pie-shaped, 6uch that a circular edge of each filter segment extends from the perimeter of the hub, with ~he opposing edge o~ the filter segment being secured between the front piece and the back piece of said hub.
An advantage of the inven~ion is that i~ is a low cost color wheel, rp~rared ~o previously used dichroic glass color wheels. It is ~.e~ble to mass production and may be made entirely fro~ plastic materials. The color wheel~is lightweight, and less prone to vibra~ion.
I~s low inertia permits faster spin-up times during operation. In embo~im~nts having a two-piece hub, built-in clamping features can be provided for attachment Qf the color wheel to the chaft of the color wheel mo~or.
AUSOI ~17 1 MRY 20'96 17:32 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.06/20 A~1~K~JS DOCKET PATENT APPLICATION
TI-18a88 5 21 78~48 BRI~F DESCRIPTION OF THE DRAW~NGS
FIGUR~ 1 is a block diagram of a display system ha~ing a color wheel configured and operated in accordance with the invention.
FIGURE 2 is a front view of a color wheel in accordance with the invention.
FIGURE 3 is a side ~iew of a color wheel in accordance with the in~ention FIGU~E 4 is an exploded side view of the color wheel, illustrating ~elf-a~taching mean~ for securing the two pieces of the hub together.
FIGURE 5 is a front view of an alternative embodiment of the color wheel, which has a single-piece fil~er AUS01-~617 1 ~RY 20'96 17:32 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.07/20 All~KN~'S DOCKET PATE~T APPLICATION
_ TI-18888 DETAILED DESCRIPTIO~ OF THE lNv~llON
Displav System O~erview The following description is in terms of a display system that displays image~ generated by an SLM or other pixel array display device. The ~erm ~pixel array display device~ is used in a broad sense to include any type of array that generates a display using individually addressed pixels. Thus, ~or example, the display de~ice migh~ be a liquid crystal array. However, the in~ention is not limited to such de~ices, and could ~e used with any di~play system chat uses a color wheel for sequential color displays. For example, the data described herein could be converted to an analog signal for use by a white light CRT whose images are ~iltered by a color wheel.
FIGURE 1 is a block diagram of a typical SLM-based image display system 10 that u~es a color wheel 15 in accordance with the in~ention.
In the example of FIGURE 1, color wheel 15 has three filter segments, one red, one green, one blue. However, ocher colors could be used, and fewer or more than three colors could be used. As explained below, the in~en~ion is directed to a color wheel who~e filter segments are made from thin plastic film at the outer circumference of a hub.
The following overview of ~he ~arious components of display syste~ 10 provides details helpful to understanding of the invention. Further details pertaining to a DMD-based image display sys~em with other types of color wheels are set out in U.S. Pacent No.
5,079,S44, entitled "Standard Independent ~igitized ~ideo System"; In U.S. Pacent serial No. 08/1~7,249, entitled "Digital Television Systeml'; and in U.S. Patent Serial No 08~146,385, en~itled ~DMD Display System" Further ,'1, 1)~it~ 1 ~1~6 1 7. 1 ~RY 20'96 17:33 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.08/20 ATTORNEY'S DOCK~T PATENT APPLIC~TIO~
details describing the general operation of color wheels fo~ SLM-based display systems are set out in U.S. Patent No. 5,2~3,385, enti1led "White Light ~nhanced Color Field Seq~ential Projection"; U.S. Patent Serial No.
08~179,028, entitled "Method and ApparatuS for Sequential Color Imaging~; and ~.S. Patent Serial No. 08/339,379, entitled "Digital Motor Controller for Color Wheel".
Each of these patents and patent applica~ions is assigned to Texas Instruments Incorporated, and each is incorporated herein by reference.
Signal interface 11 receives so~e kind of input signal. For purposes of example herein, it will be assumed that the input signal is a st~nd~rd analog video signal having horizontal and vercical synchronization components. However, in other sys~ems, the input signal mighc be graphics data already in digital form.
In the case of a video input signal, interface 11 separates t~e video signal from synchronization and audio signals. It includes an A/D conve~ter and a Y/C
separator, which con~ert the data into pixel data samples and separate the lumjn~nce data from the chro~;n~ce data. The signal could be converted to digital data.
before Y/C conversion or Y/C ~eparation co~ld occur before digitization.
Pixel data processor 12 prepares the data for display, by performing various processing tasks.
Processor 12 includes processing memory for storing pixel data during processing. The tasks performed by processor 13 may include linearization, colorspace conversion, and line generation. Linearization remo~es the effect of gamma correction, which is performed on broadcast si~nals to compensate for che no~-linear operation of CRT
displays. Colorspace conversion converts the data to RGs data. Line generation can be used to convert interlaced ~uso~ 17.~
~Y 20'96 17:33 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES-GRLE P.09/20 AL-1~ S DOCKET PATENT APPLICATIN
fields of data into complete frames by generating new data to fill in odd or e~en lines The order in which these tasks are performed may vary Display memory 13 receives processed pixel data from processor 12. Display memory 13 formats the data, on input or on outpu~, into "bit-plane" ~ormat and deli~ers the bit-planes to SLM 14. The bi~-plane format provides one bit at a time for each pixel of SLM 14 and permits each pixel to ~e turned on or off in accordance with the weight of that ~it. For example, where each pixel is represented by 8 bit~i for each of three colors, there will be 3 x 8 , 24 bit-planes per frame. Bit-planes cont~;n;ng less significant bits will result in shorter display times than the bit-planes containing more significant bits.
In a typical display system 10, memory 13 is a double-buffer memory, which means that it has a capacity for at least tWO display frames. The buffer for one display frame can be read out to SLM 14 while the buffer or another display frame is being written. The two buffers are controlled in a "ping-pong" manner so that data is continuously a~ailable to SLM 14.
SLM 14 may be any type of SLM. For purposes of example, this description is in terms of a display system whose SLM is a digital micro-mirror device (DMD).
However, as stated abo~e, the same concepts apply to display systems that use other types of SLMs or other image generating devices.
Light incident on SLM 14 is provided by a light source 16 and is transmitted through a rotacing color wheel 15. In the system o~ FIGURE 1, SLM l~ is a reflective SLM (a DMD), and the color wheel 15 is used to filter the light before reflection As an alterna~ive, AUli~ 4~617.1 MRY 20196 17: 33 FR TEXRS I NST . LEG~L DEP 14 995 351 1 TO K I RBY, ERDES . G~LE P . 10/20 AL1O~N~;Y ~ S DOCRET PAI~NT AppLIc~TION
the color w~eel 15 could be placed so that light is filtered a~ter being emi~ted or reflected.
As ~xplain~d in the Background, the data for each color are sequenced and the display of the data is s synchronized so that the portion of color wheel 15 through which light is being transmitted to ~LM 14 corresponds to the data being displayed. In the example of this description, each pixel is rep~esented by RGB
data, which means that each pixel has a red value, a O green value, and a blue value. As the values for each color of all pixels in a frame are being displayed, color wheel 15 rotate~ so that the light is transmitted through the corresp~; n~ red, blue or green fileer. For each pixel, the com~ina~ion of these three values is perceived as the desired color.
Color wheel 1~ i~ dri~en by a motor 15a ~ia shaft l5b. Motor l5a includes a controller that control~ the speed and p~ase o~ color wheel 15. For example, the desired speed might be 60 revolutions per second to correspond ~o a 60 frame per second display rate. The phase is set so that the proper filter (red, green, or blue) of color wheel 15 is transmitting light from SLM 14 as the data for that filter is being displayed. To maintain a correct phase relationship between the color wheel 15 and the data being displayed, the color wheel 15 can ~peed up or slow down or the data can be delayed or skipped.
For a DMD-based system, the data delivered ~o sLM 14 is in a special bit-plane format for pulse width modulation. Each red, green, and blue value of a pixel has n bits per ~rame. A pixel value of 0 (black) results in the pixel being off for that color d~ring the f rame.
~or each color, each mirror element of the SLM 14 can be "on" for a dur~tion of anywhere from 1 LSB period to 2n-AUSOI ;~617., MRY 20'96 17:34 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.11/20 ATTORNEY~S DOCRET PATE~T APPLICATION
_ TI-18888 lo 2 1 78848 LSB periods. ~n other words, each color has 2~-1 time slices, duri~g which any pixel can be on for any number of ti~e slices between 0 and 2n-l.
Where a frame o~ data is displayed for a frame period of T seconds, color wheel 15 has a period of revolution of T seconds. If each color were to be displayed for an equal time, the color wheel 15 would have equally sized segmentQ of each color and the data for each color would then be displayed for T/3 seconds.
The LSB period would be the frame time for each color divided by the number of LSB periods for that color.
Master timing unit 18 provides various sys~em control functions. One timing signal provided by master timing unit 18 is a signal defining the display times for each bit weight of the pixel value.
Although not illustrated in FIGURE 1, system 10 also includes a projection lens and ~arious other optical devices for collecting and projecting the image from SLM
14 to the image plane (screen).
FIGUREs 2 and 3 are a front view and a side view, respecti~ely, of color wheel 15 A typical si2e of color wheel 15 is approximately 4 inches in dia~eter for incident light having a spot size of 4 - 6 millimeters.
This size is sufficiently large so as to minimize the time when the incident light coincides with a spoke 24 or other transition beeween filter segments 21 Color wheel 15 is comprised of a rigid two-piece hub 23, which has a front piece 23a and a back piece 23b.
Front p~ece 23a and ~ack piece 23b are attached in a manner that clamps filter segments 21 into place. An example of a suitable material for hub 23 is plastic, which may be easily molded to form pieces 23a and 23b.
In the example of this descr,ption, color wheel 15 ha~ ~hree filter segmen~s 21, one for each of ~hre~
AUs~ 6l7 1 RY 20'96 17:34 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES.GRLE P.12/20 Allu~N~S DOCgET PATENT APPLICATION
~I-18888 primary colors: red, blue and green. However, in other embodiments, there could be more than one segment for each color. There mig~t also be segments for more or for fewer colors, and there might be a clear segment. Each 5 filter ~egment 21 i9 made from a thin plastic ma~erial.
Examples of ~ultable materials are mylar or pol~ester film. The plastic is impregnated wich dye, or otherwise made to crea~e an absorp~ive filter to obtain the desired color. A feature of the invention i9 that filter 0 ~egments 21 need not be rigid and can be made from rela~ively flexible materials.
Each filter segment 21 is substantially pie-shaped, so that its inner area can be clamped within hu~ 23 and i~s circular outer perimeter can excend out from hub 23.
The two pieces 23a and 23b of hub 23 snap or otherwise attach together, thereby "~andwiching" the appropriate portion of filter segments 21.
As illustrated in FIGURE 2, the front piece 23a and back piece of 23b ha~e a spoke 24 at each junction of one filter segment 21 to another. This contemplates that filter ~egments 21 will be comprised of separate pieces.
The spokes 24 join the abutting edges of adjacent filter segments 21 and prevent wind resis~ance at these edges during operation as well as add stiffness eo the fil~er portion of the color wheel 15.
Various mechanical features can ~e easily molded to the inner surfaces of pieces 23a and 2~b so that these pieces can be self-securing when pressed together. For example, as illustrated in FIGUR~ 4, one piece 23a might have a plastic sleeve 41 protruding from its inner surface. The other piece 23b has a corresponding center opening for receiving the sleeve, with the diameter of the opening being of a size that will provide a snug fit of slee~e 41 Sleeve 41 hae a wedge ~la t.ha~ snap~ into AUS01:L1617.1 ~RY 20'96 17:34 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY,ERDES,GRLE P.13/20 Ar-l~N~Y~S DOCXET ~ATENT APPLICATIO~
a wedge-shaped enlargement of the opening in piece 23b.
This permits pieces 23a and 23b to be clamped to shaft l5b without additional parts. Other built-in mechanical feacures can easily be imagined, with interlocking wedges or other features for attaching the hu~ 23 to the color wheel motor shaft l5b. Ex~rinsic fastening means, such as screws, can also be used.
The thickness of filter segments 21 is a balance between ~eing sufficiently thick to provide some stiffness and sufficiently thin so as co minimize loss of light. To some extent, centrifugal force during opera~ion can compensate for lack of stiffneæs. Typical thicknesses of filter segments 21 are ~etween 1 and 2 ~illimeters.
l$ As illustrated in FIGURE 3, hub 23 may be made thicker at its mid-portion where it is attached to the drive shaft of the color wheel motor. This result~ in hub 23 being ~mass loaded'~ around che drive shaft of the color wheel motor and enhances proper balance.
In an alternati~e PmhoA;ment, color wheel 15 could have a hub 23 that is comprised of only one piece 23a.
The filter segments 21 would be attached to one side.of hub 23, around its perimeter, by means such as glue. As discussed above, hu~ 23 may have spokes 24, to which the filter segments 21 would be attached, either to join edges of separate filter segments 21 or to add stiffness ~o the filter portion of the color wheel.
FIGURE S illustrate~ another embodiment of color wheel 15, where all filter segments 21 are made from a single piece of material having differently colored areas, each forming a different fil~er segment 21. The fil~er segments ~1 are ring-shaped, and may be attached between two pieces 23a and 23b of hub 23 or attached to one side of a single-piece hu~ 23~ Tn this case, spokes Ausl)~ 617,1 ~RY 20'96 17:34 FR TEXRS INST. LEGRL DEP 14 995 3511 TO KIRBY.ERDES,GRLE P.14/20 ~l'L~ S DOCKET PATENT APPLICATION
24 might not be necessary depending on the stif~ness of the filter matexial.
In operation, color wheel lS is rotated sufficiently fast -~o as to introduce a radial airflow that cools the filter segments 21 from the absorbed radiation. A
rotation speed of approximately 3600 revolutions per minute has been found to be satisfactory.
Other Embo~ nts Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed em~odiments, as well as alternati~e em~odimen~s, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the in~ention.
, AUSOI ~617.1
Claims (20)
1. A color wheel for a display system, comprising:
a hub having a generally circular shape and being made from a rigid material; and two or more color filter segments made from a plastic material, said filter segments being substantially pie-shaped and attached to said hub such that circular edges of said filter segments extend from said hub and opposing edges of said filter segments are secured to said hub.
a hub having a generally circular shape and being made from a rigid material; and two or more color filter segments made from a plastic material, said filter segments being substantially pie-shaped and attached to said hub such that circular edges of said filter segments extend from said hub and opposing edges of said filter segments are secured to said hub.
2. The color wheel of Claim 1, wherein said hub has a front piece and a back piece for attachment together, and wherein said filter segments are secured between said front piece and said back piece.
3. The color wheel of Claim 2, wherein said front piece and said back piece have self-attaching means for attaching said front piece to said back piece.
4. The color wheel of Claim 2, wherein one of said front piece or said back piece has a sleeve extending from its inner center surface for attachment around a shaft of said color wheel and the other of said front piece or said back piece has a corresponding opening in its inner center surface for receiving said sleeve.
5. The color wheel of Claim 1, wherein said filter segments are attached to one side of said hub.
6. The color wheel of Claim 1, wherein said filter segments are absorptive color filter segments.
7. The color wheel of Claim 1, wherein said hub is made from a plastic material.
8. The color wheel of Claim 1, wherein said filter segments are made from a plastic material.
9. The color wheel of Claim 1, wherein said filter segments are in the order of 1 millimeter thick.
10. The color wheel of Claim 1, wherein said hub is thicker at its center than at its perimeter.
11. A color wheel for a display system, comprising:
a hub having a generally circular shape and being made from a rigid material; and a color filter made from a plastic material, said filter being substantially ring-shaped and attached around a perimeter of said hub such that an outer circular edge of said filter extends from said hub and an inner circular edge of said filter is attached to said hub.
a hub having a generally circular shape and being made from a rigid material; and a color filter made from a plastic material, said filter being substantially ring-shaped and attached around a perimeter of said hub such that an outer circular edge of said filter extends from said hub and an inner circular edge of said filter is attached to said hub.
12. The color wheel of Claim 10, wherein said hub has a front piece and a back piece for attachment together, and wherein said filter is secured between said front piece and said back piece.
13. The color wheel of Claim 11, wherein said front piece and said back piece have self-attaching means for attaching said front piece to said back piece.
14. The color wheel of Claim 2, wherein one of said front piece or said back piece has a sleeve extending from its inner center surface for attachment around a shaft of said color wheel and the other of said front piece or said back piece has a corresponding opening in its inner center surface for receiving said sleeve.
15. The color wheel of Claim 10, wherein said filter is attached to one side of said hub.
16. The color wheel of Claim 10, wherein said filter is an absorptive color filter.
17. The color wheel of Claim 10, wherein said hub is made from a plastic material.
18. The color wheel of Claim 10, wherein said filter is made from a plastic material.
19. The color wheel of Claim 10, wherein said filter is in the order of 1 millimeter thick
20. The color wheel of Claim 1, wherein said hub is thicker at its center than at its perimeter.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/489,979 US5777694A (en) | 1995-06-13 | 1995-06-13 | Color wheel with plastic film filters |
| US489,979 | 1995-06-13 |
Publications (1)
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| CA2178848A1 true CA2178848A1 (en) | 1996-12-14 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002178848A Abandoned CA2178848A1 (en) | 1995-06-13 | 1996-06-12 | Color wheel with plastic film filters |
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| US (1) | US5777694A (en) |
| EP (1) | EP0749246B1 (en) |
| JP (1) | JPH095515A (en) |
| KR (1) | KR980004301A (en) |
| CA (1) | CA2178848A1 (en) |
| DE (1) | DE69611482T2 (en) |
| TW (1) | TW319859B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6002452A (en) * | 1995-06-08 | 1999-12-14 | Texas Instruments Incorporated | Sequential color display system with spoke synchronous frame rate conversion |
| US5863125A (en) * | 1998-01-30 | 1999-01-26 | International Business Machines Corporation | High efficiency two-SLM projector employing total-internal-reflection prism |
| US5921650A (en) * | 1998-02-27 | 1999-07-13 | International Business Machines Corporation | High efficiency field-sequential color projector using two SLMs |
| JPH11295622A (en) * | 1998-04-10 | 1999-10-29 | Minolta Co Ltd | Illumination device |
| US6288815B1 (en) | 1999-03-31 | 2001-09-11 | Philips Electronics North America Corporation | Light scanner with cylindrical lenses |
| JP2001014911A (en) | 1999-06-28 | 2001-01-19 | Minolta Co Ltd | Lighting system |
| US6361172B1 (en) * | 2000-03-20 | 2002-03-26 | Philips Electronics North America Corporation | Color projection system incorporating electro-optic light modulator and rotating light-transmissive element |
| US6870523B1 (en) * | 2000-06-07 | 2005-03-22 | Genoa Color Technologies | Device, system and method for electronic true color display |
| US7116378B1 (en) * | 2000-08-15 | 2006-10-03 | Displaytech, Inc. | Color-balanced brightness enhancement for display systems |
| KR100381264B1 (en) * | 2000-11-15 | 2003-05-01 | 엘지전자 주식회사 | Color division device for liquid crystal display projector of single panel type |
| US6726333B2 (en) | 2001-02-09 | 2004-04-27 | Reflectivity, Inc | Projection display with multiply filtered light |
| US7046221B1 (en) | 2001-10-09 | 2006-05-16 | Displaytech, Inc. | Increasing brightness in field-sequential color displays |
| TW563794U (en) * | 2002-05-15 | 2003-11-21 | Young Optics Inc | Color wheel |
| TW577550U (en) * | 2002-10-02 | 2004-02-21 | Prodisc Technology Inc | Color wheel and washer for color wheel |
| US6754014B1 (en) * | 2003-02-21 | 2004-06-22 | Prodisc Technology Inc. | Color wheel |
| US7131762B2 (en) * | 2003-07-25 | 2006-11-07 | Texas Instruments Incorporated | Color rendering of illumination light in display systems |
| US7212359B2 (en) * | 2003-07-25 | 2007-05-01 | Texas Instruments Incorporated | Color rendering of illumination light in display systems |
| TWI226942B (en) * | 2003-11-11 | 2005-01-21 | Asia Optical Co Inc | Filter set and color wheel with the filter set |
| US7457063B2 (en) * | 2004-03-01 | 2008-11-25 | Asia Optical Co., Inc. | Color wheel and color filter assembly thereof |
| TWI280418B (en) * | 2004-06-16 | 2007-05-01 | Coretronic Corp | Combination structure of color wheel |
| ATE436038T1 (en) * | 2005-04-22 | 2009-07-15 | Oerlikon Trading Ag | COLOR WHEEL WITH SELF-ADJUSTED SEGMENTS |
| JP2007080796A (en) * | 2005-09-16 | 2007-03-29 | Toshiba Corp | Light source lamp |
| DE102006020648B4 (en) * | 2006-05-02 | 2020-06-10 | Oerlikon Trading Ag, Trübbach | Process for producing a color wheel |
| CN104880819B (en) * | 2015-05-28 | 2017-05-03 | 苏州佳世达光电有限公司 | Color wheel and projection system using same |
| CN111323936B (en) * | 2018-11-29 | 2022-03-08 | 成都理想境界科技有限公司 | Projection display system, 3D glasses and projection method |
| CN112887689A (en) * | 2021-01-21 | 2021-06-01 | 联想(北京)有限公司 | Display method and device |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4667229A (en) * | 1984-05-18 | 1987-05-19 | Fuji Photo Optical Company, Ltd. | Color video endoscope system |
| DE3614888A1 (en) * | 1986-05-02 | 1987-11-05 | Hell Rudolf Dr Ing Gmbh | OPTICAL ARRANGEMENT FOR LINEAR LIGHTING OF SCAN TEMPLATES |
| US4800474A (en) * | 1986-05-15 | 1989-01-24 | Vari-Lite, Inc. | Color wheel assembly for lighting equipment |
| US4909600A (en) * | 1988-10-28 | 1990-03-20 | Welch Allyn, Inc. | Light chopper assembly |
| JPH02119005A (en) * | 1988-10-28 | 1990-05-07 | Fuji Photo Optical Co Ltd | Lighting unit |
| US5079544A (en) * | 1989-02-27 | 1992-01-07 | Texas Instruments Incorporated | Standard independent digitized video system |
| JP2964715B2 (en) * | 1991-07-01 | 1999-10-18 | 富士写真光機株式会社 | Electronic endoscope system |
| US5233385A (en) * | 1991-12-18 | 1993-08-03 | Texas Instruments Incorporated | White light enhanced color field sequential projection |
| US5371543A (en) * | 1993-03-03 | 1994-12-06 | Texas Instruments Incorporated | Monolithic color wheel |
| US5426576A (en) * | 1993-04-23 | 1995-06-20 | Light & Sound Design, Limited | Colour cross-fading system for a luminaire |
| US5650832A (en) * | 1995-06-13 | 1997-07-22 | Texas Instruments Incorporated | Multimode color wheel for display device |
-
1995
- 1995-06-13 US US08/489,979 patent/US5777694A/en not_active Expired - Lifetime
-
1996
- 1996-06-01 KR KR1019960019517A patent/KR980004301A/en active IP Right Grant
- 1996-06-12 JP JP8151396A patent/JPH095515A/en active Pending
- 1996-06-12 CA CA002178848A patent/CA2178848A1/en not_active Abandoned
- 1996-06-13 EP EP96109494A patent/EP0749246B1/en not_active Expired - Lifetime
- 1996-06-13 DE DE69611482T patent/DE69611482T2/en not_active Expired - Fee Related
- 1996-07-09 TW TW085108260A patent/TW319859B/zh active
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| KR980004301A (en) | 1998-03-30 |
| DE69611482T2 (en) | 2001-07-05 |
| EP0749246A1 (en) | 1996-12-18 |
| US5777694A (en) | 1998-07-07 |
| EP0749246B1 (en) | 2001-01-10 |
| JPH095515A (en) | 1997-01-10 |
| TW319859B (en) | 1997-11-11 |
| DE69611482D1 (en) | 2001-02-15 |
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