WO2001040909A1

WO2001040909A1 - Stereoscopic 3d personal computer

Info

Publication number: WO2001040909A1
Application number: PCT/KR2000/001407
Authority: WO
Inventors: Youn Woo Lee
Original assignee: Stereopia Co., Ltd.; Neotek Research Co., Ltd.
Priority date: 1999-12-04
Filing date: 2000-12-04
Publication date: 2001-06-07
Also published as: AU2025601A

Abstract

Disclosed is a stereoscopic 3D personal computer adapted to display the 3D image using a liquid crystal, comprising: an image display means adapted to display images synthesized through a camera thereon; a liquid crystal panel adapted to control the direction of light outgoing from the image display means; a pair optical polarizing glasses worn by the observer to allow each of both eyes of an observer to see only an image of the light passing through the liquid crystal panel; and a driver means adapted to synchronize the liquid crystal panel with the image display means. Accordingly, with no adding a separate wired or wireless synchronizing circuit to a pair of optical polarizing eyeglasses worn by the observer, an observer can see the stereoscopic image and the occurrence of an erroneous operation due to a response to an external light source is prevented.

Description

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ΦττrHMτr-aτ. τrτπτ.n The present invention relates to a stereoscopic 3D personal computer for displaying a stereoscopic image , and more particularly, a stereoscopic 3D personal computer with a liquid crystal panel as a control unit of light direction .

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When an observer's both eyes see a real object, images formed on respective retinas of both eyes are obtained a little differently from each other due to a distance (2.5 inches) between both eyes. A difference in a horizontal distance for an identical object point at images projected onto the respective retinas is called 'image disparity' , which allows an observer to feel depth sense through the interpretation of the distance difference (image disparity) by his/her brain. Like this, there is known a method of implementing a stereoscopic image by using a characteristic that when the two stereoscopically generated images are seen on respective retinas in both eyes of an observer, the observer can perceive a sort of a stereoscopic or three-dimensional (3D) image. Such a method is called a "stereoscopic imaging method". Researches to implement such a method have been carried out for a long time steadily. Many stereoscopic devices using eyeglasses have been developed and some of them have been commercialized. There is the most popular method of producing such a stereoscopic image in which after two synchronized (gen- locked) cameras are disposed in such a fashion that they are spaced apart from each other by a distance between both eyes of an observer, if an image generated from the left camera is constituted in one field, and an image generated from the right camera is constituted in the other field, although resolution is reduced to 50% in a vertical direction with compared to the original image (frame) , a stereoscopic image can be produced even pursuant to a conventional interlaced scanning TV system.

In the meantime, it is the most popular technology for implementing the stereoscopic image to use a pair of liquid crystal shutters as eyeglasses (also referred to as "viewing glasses") to see stereoscopic images. In this technology, an application of a characteristic of liquid crystal that possesses both fluidity of liquid and optical anisotropy of crystal allows two eyes of an observer to see different images, respectively.

Figs, la to Id are conceptional views illustrating the transmission and direction control of the light using liquid crystal . Fig. la is a conceptional view illustrating an orientation state of the liquid crystals.

Referring to Fig. la, in an initial natural state, the liquid crystal molecules 101 are arranged in an irregular state, but the application of electrical stimulus to the liquid crystal molecules 101 or the mounting of direction plates to both ends of the liquid crystal molecules 101 allows transmission and direction of light to be controlled. More specifically, when two glass substrates 102 are disposed in such a fashion that they are face to face, i.e., the upper glass substrate is opposite to the lower glass substrate, and an orientation film 103 having a plurality of grooves formed thereon in a certain direction is positioned on the facing inner surfaces of tne upper and lower glass substrates 102, respectively, and after the two orientation films 103 are aligned to be crossed each other at the angle of 90 degrees, the liquid crystal molecules 101 are contained in the region between the two orientation films 103, then the liquid crystal molecules 101 are aligned along the grooves of the two orientation films 103. At this time, since the two orientation films 103 are crossed each other at the angle of 90 degrees, the liquid crystal molecules are also aligned to undergo a continuous 90° twist from the upper orientation film to the lower orientation film in the middle area.

When light is transmitted to a liquid crystal panel made in this manner, incoming light is crossed each other with outgoing light as shown in Fig. lb. The reason for this is that the light passes through the continuously 90° twisted liquid crystal molecules 101.

Likewise, the use of liquid crystal molecules 101 enables a change in the transmission direction of light. If a predetermined voltage is applied to the liquid crystal cells across the upper and lower glass substrates 102, the liquid crystal molecules 101 are aligned to perpendicular to the glass substrates 102. So the incoming light passes through the glass substrates 102 in a vertical direction, which has no effect on light direction in spite of the 90° twisted alignment of two orientation films.

Meanwhile, as shown in Fig. lc, a pair of polarizing filter 104 is used to transmit or occlude light according to the combination of polarization direction.

Fig. Id is a conceptional view illustrating transmission control of light with or without application of voltage.

Referring to Fig. Id, the upper polarizing filter 104 having the same direction as that of the upper orientation film 103 is disposed on the outer surfaces of the glass substrates 102 without application of voltage. The light parallel to a filter grating first passes through the upper polarizing filter. At this point, the passed light is twisted by 90° continuously between the aligned liquid crystal molecules, so that the light which has reached the lower orientation film passes through the lower polarizing filter because of the lower polarizing filter having the same direction as that of the lower orientation film. On the contrary, if two polarizing filters are arranged to be crossed with each other on the outer surfaces of two glass substrates and a predetermined voltage is applied to the liquid crystal cells across the upper and lower glass substrates 102, - even though light can pass through the region between two substrates - outgoing light is occluded completely due to the two polarizing filters 104.

Fig. 2 is a schematic view illustrating a state in which a conventional stereoscopic 3D personal computer is used according to the prior art. As shown in Fig. 2, there is shown a conventional stereoscopic 3D personal computer using controllability of light transmission which liquid crystal possesses, m which two field images are synthesized into a single stereoscopic image in such a fashion that the left field image is scanned in an odd line and the right field image is scanned m an even line, or vice versa to display the synthesized single three- dimensional (3D) or stereoscopic image frame on a monitor 111. At this point, by using a pair of liquid crystal shutters 112 or eyeglasses synchronized with the images displayed on the monitor 111, when the left field image is displayed thereon, a right shutter 112a is closed and a left shutter 112b is opened to allow only the left eye to see the left image. On the contrary, when the right field image is displayed thereon, the left shutter 112b is closed and the right shutter 112a is opened to allow only the right eye to see the right image. In such a method, an observer can see the synthesized stereoscopic image displayed on the monitor 111.

As described above, such a conventional stereoscopic 3D personal computer employs the same scanning method as the existing interlaced scanning TV system. However, for this interlaced scanning TV system, 30 frames per second are displayed on the left and right screen regions of the monitor 111, respectively, so that an observer feels "flicker". Therefore, when the observer sees the synthesized stereoscopic image under this condition, he or she suffers from physically harmful side effects such as a headache, etc. In such a stereoscopic 3D personal computer, at least 50 or more frames per second must be displayed on the left and right screen regions of the monitor 111, respectively, for an observer to see a good stereoscopic image.

In addition, since the stereoscopic imaging method requires that a circuit for, at high speed, switching the pair of liquid crystal shutters 112 synchronized with the images displayed on the monitor 111 in a cable 113 or a wireless type be constructed, this expedient inherently increases the weight of the liquid crystal shutters 112 somewhat so that when an observer wears the liquid crystal shutters 112, he or she feels inconvenience. For the wireless type using the infrared rays as a control source of the shutter (on-off) operation, there has also been a problem that it can cause an erroneous operation by an infrared source such as an electric light bulb, etc.

nτc!f-r.r>c;ττ^pτπ ΓΓF ττj .τjττnτ Therefore, the present invention has been made in view of the above-mentioned problems, and it is an ob ect of the present invention to provide a stereoscopic 3D personal computer m which a separate synchronizing circuit is not constructed in a pair of eyeglasses or shutters so that the weight of the shutter glasses is reduced, and which prevents occurrence of an erroneous operation due to a response to external infrared light sources.

According to the present invention, there is provided a stereoscopic 3D personal computer, comprising: an image display unit adapted to display a stereoscopic image synthesized through a photographing unit thereon; a light conbrol unit adapted to control the emission direction of light outgoing from the image display unit, the light control unit being mounted to the front surface of the image display unit; an image separating unit adapted to allow each of both eyes of an observer to see only an image corresponding to each of both eyes along a path of the light passing through the light control unit; and a driver unit adapted to synchronize the light control unit with the image display unit to drive the light control unit .

According to the stereoscopic 3D personal computer of the present invention, since an observer can view a three- dimensional (3D) or stereoscopic image even without adding a separate wired or wireless synchronizing circuit to a pair of optical polarizing eyeglasses which the observer wears, the weight of the eyeglasses is reduced and it becomes convenient to wear the eyeglasses accordingly, and occurrence of an erroneous operation is prevented due to response to external infrared light sources. P-PTTTΓ nπ.qrpτpττπw rπr THTΓ. npawTwr-jg

The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:

Figs, la to Id are conceptional views illustrating a controlled transmission direction of light using liquid crystals; Fig. 2 is a schematic view illustrating a conventional stereoscopic 3D personal computer in use according to the prior art;

Fig. 3 is a schematic exploded perspective view illustrating a stereoscopic 3D personal computer in use according to a preferred embodiment of the present invention; and

Fig. 4 is a block diagram illustrating the construction of the stereoscopic 3D personal computer according to a preferred embodiment of the present invention.

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Reference will now be made in detail to the preferred embodiments of the present invention.

Fig. 3 is a schematic exploded perspective view illustrating a state in which a stereoscopic 3D personal computer is used according to a preferred embodiment of the present invention.

Fig. 4 is a block diagram illustrating the construction of the stereoscopic 3D personal computer acccording to a preferred embodiment of the present invention.

Referring to Figs. 3 and 4, there is shown a stereoscopic 3D personal computer comprising an image display unit 20, a light control unit 30, an image separating unit 40, and a driver unit 50. The image display unit 20 is adapted to display stereoscopic images synthesized through a photographing unit 10 such as a stereoscopic camera thereon. The image display unit 20 comprises any one selected from CRT (Cathode Ray Tube), LCD (Liquid Crystal Display), PDP( Plasma Display Panel), FED (Field Emission Display).

The light control unit 30, which is mounted to the front surface of the image display unit 20, is adapted to control the emission direction of light outgoing from the image display unit 20. The light control unit 30 may be a liquid crystal display panel.

Here, the liquid crystal display panel used as the light control unit 30 is constructed in such a fashion that two orientation films and electrodes are laminated to be opposite to each other on the inner surfaces of two glass substrates, i.e. the upper and lower glass substrates, respectively, and a layer of liquid crystal molecules is sandwiched between the two glass substrates. At this time, when the two orientation films are arranged to be crossed each other at the angle of 90 degrees, the incoming light is transmitted while outgoing light undergoes a 90° phase shift to the incoming light, and when a predetermined voltage is applied to the liquid crystal molecules across the two electrodes, the incoming light passes through the two orientation films as it is while the outgoing light does not undergo a 90° phase shift to the incoming light.

The image separating unit 40 is adapted to allow each of the both eyes of an observer to see only an image corresponding to each of the both eyes along a path of the light passing through the light control unit 30. The image separating unit 40 may be a pair of optical polarizing eyeglasses.

Also, the pair of polarizing eyeglasses used as the image separating unit 40 includes a pair of polarizer sheets 41 and 42 which are crossed each other at a right angle so that an observer can view a three-dimensional (3D) or stereoscopic image. The polarizing eyeglasses 40 is also designed in such a fashion that when left and right images displayed on the image display unit 20 is transmitted into the liquid crystal display panel 30, the polarizing eyeglasses 40 selects the transmitted left and right images so that an observer' s left eye can see only the left image and the observer's right eye can see only the right image.

And, the driver unit 50 is adapted to synchronize the light control unit 30 with the image display unit 20 to drive the light control unit 30.

A process for providing an observer with a stereoscopic image through the above mentioned stereoscopic 3D personal computer will be described hereinafter in detail.

First, two cameras 10 as a photographing unit disposed to oe spaced apart from each other by a distance between two eyes of an observer photograph an object, respectively, and then applies the left and right images for the object photographed through the two cameras 10 to the image display unit 20 which synthesizes the left and right images. At this time, the image display unit 20 constitutes the left image formed on the left camera in one field, and constitutes the right image formed on the right camera m the other field to display a synthesized stereoscopic image frame thereon.

Likewise, when one image field constituting the synthesized stereoscopic image is displayed on the image display unit 20, the liquid crystal display panel 30 mounted to the front surface of the image display unit 20 is synchronized with the image display unit 20 through the driver unit 50. At this time, when two orientation films of the liquid crystal display panel 30 are aligned to be crossed each other at a right angle, incoming light is transmitted while outgoing light undergoes a 90° phase shift to the incoming light. On the contrary, m the case where the other image field constituting the synthesized stereoscopic image is displayed on the image display unit 20, when a predetermined voltage is applied to the liquid crystal molecules across the two orientation films, the incoming light passes through the two orientation films as it is while the outgoing light does not undergo a 90° phase shift to the incoming light.

Therefore, the transmission direction of a polarized light transmitted to the liquid crystal display panel 30 varies with whether or not a voltage is applied across the two electrodes. In the case where the transmission direction of a light passing through the liquid crystal display panel 30 is identical to the polarizing direction of the pair of polarizer sheets 41 and 42 of the optical polarizing eyeglasses 40 which an observer worn, the observer can view a stereoscopic image through each of his/her two eyes.

As a consequence, the observer sees the left image and the right image allowing him/her to perceive artificial parallax between two eyes through the left eye and the right eye, respectively, so that he/she can feel a depth sense.

Here, when each of the two eyes sees 50 or more frames per second being displayed on the image display unit 20, the observer can see a good stereoscopic image without suffering from a flicker phenomenon when viewing different images. Also, the image displayed on the image display unit 20 may be moved in a specified direction through a three- dimensional mouse or joystick, or an audio/video recognizing function, or may be :lιcked spatially.

In the meantime, in the case where a partial region of the image display unit 20 is formed by a stereoscopic image, the region formed by the stereoscopic image and the remaining region except the region formed by the stereoscopic image have to be displayed differently. For this purpose, the image display unit 20 includes a display detector 21 adapted to detect the region formed by the stereoscopic image and a displaying of the image is controlled by the controller 22 according to a signal detected by the display detector 21.

That is, according to a detecting signal outputted from the display detector 21, for the remaining region not forming a stereoscopic image, the controller 22 allows the image display unit 20 to display the image as it is, and for the region forming the stereoscopic image, the controller 22 regenerates a empty scanning line which has not been implemented vertically through an interpolation of the upper and lower portions or a copy of an image in the upper portion, so that a complete non-interlaced image of two stereoscopic frames can be controlled by the stereoscopic image display method.

As a result, even n the remaining region of a monitor screen except the region forming the stereoscopic image, for example, a background screen of an image display unit like a computer monitor, fonts or letters is not broken, and a complete image can be displayed in the left and right regions of the monitor screen. Of course, if this operation is performed, a complete non-interlaced image of two frames is displayed finally, but data of the region forming a stereoscopic image can constitute a complete stereoscopic frame image even without forming the image of two full frames. As can be seen from the foregoing, according to a stereoscopic 3D personal computer of the present invention, since an observer can view a three-dimensional (3D) or stereoscopic image even with a pair of optical polarizing eyeglasses which the observer wears, the weight of the eyeglasses is reduced so that it becomes convenient to wear the eyeglasses accordingly, and occurrence of an erroneous operation due to a response to an external light source is prevented. Further, since the stereoscopic 3D personal computer displays 50 or more frames per second in the left and right regions of a monitor screen thereof, respectively, an observer can appreciate a good stereoscopic image without suffering from a flicker phenomenon. In addition, for the remaining region of a monitor screen except the region forming the stereoscopic image, the display detector detects the remaining region, and the detected regions is displayed as it is by the image display unit 20, so that fonts or letters are not seen to be broken and an observer can see a good stereoscopic image.

While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment, but, on the contrary, it is intended to cover various modifications within the spirit and scope of the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A stereoscopic 3D personal computer, comprising: an image display means 20 adapted to display a stereoscopic image synthesized through a photographing unit 10 thereon a light control means 30 adapted to control the emission direction of light outgoing from the image display means 20, the light control means 30 being mounted to the front surface of the image display means 20; an image separating means 40 adapted to allow each of both eyes of an observer to see only an image corresponding to each of the both eyes along a path of the light passing through the light control means 30; and a driver means adapted to synchronize the light control means 30 with the image display means 20 to drive the light control means.

2. The stereoscopic 3D personal computer according to claim 1, wherein the image display means 20 comprises any one selected from CRT, LCD, PDP, FED.

3. The stereoscopic 3D personal computer according to claim 1, wherein the light control means 30 comprises a liquid crystal (LCD) panel.

4. The stereoscopic 3D personal computer according to claim 1, wherein the image separating means 40 comprises a pair of optical polarizing eyeglasses including a left polarizing shutter corresponding to the polarizing direction of the left image and a right polarizing shutter corresponding to the polarizing direction of the right image.

5. The stereoscopic 3D personal computer according to any one of claims 1 to 4, wherein the image display means 20 further comprises a display detector 21 adapted to detect whether or not an image is displayed by a stereoscopic image display method, and a controller 22 of the image display means 20 is adapted to control the displayed image according to a signal detected by the display detector 21.