CN102402016A - Silica-based liquid crystal stereo projection light machine - Google Patents

Abstract

The invention provides a silicon-based liquid crystal stereoscopic projection light machine, which can realize color three-dimensional display. The engine mainly includes an illuminating light source, two polarization splitting devices, two reflective silicon-based liquid crystal microdisplay chips, and a projection objective lens. The optical machine of the present invention adopts two polarization beam-splitting devices to allow the imaging light incident on the silicon-based liquid crystal reflective micro-display chip and reflected from the reflective silicon-based liquid crystal micro-display chip to pass through the polarization beam-splitting film of the polarization beam splitter twice, and once for One transmission is reflection, which greatly increases the extinction ratio of the working light, and makes the extinction ratio of the two outgoing polarized lights completely equal, thus effectively improving the contrast of the projected image and improving the image quality. More importantly, compared with the existing three-dimensional projection device using four polarization beam splitters, the use of two polarization beam splitters obviously reduces manufacturing cost and process difficulty, and is conducive to large-scale production. The projection light machine can also realize switching between three-dimensional and two-dimensional image display.

Description

A silicon-based liquid crystal stereoscopic projection light machine

technical field

The invention relates to a silicon-based liquid crystal projection light machine, in particular to a silicon-based liquid crystal stereoscopic projection light machine.

the

Background technique

Stereoscopic projection display is widely sought after because of its immersive visual experience. There are many kinds of technologies for realizing stereoscopic projection display, and the active stereoscopic projection technology by means of liquid crystal shutter glasses is not suitable for ordinary families with many people because of the high cost of liquid crystal shutter glasses. With the help of the dual-optical stereo projection technology of polarized glasses, the cost of the polarized glasses is low, and many people can watch it at the same time, but it is only suitable for large movie theaters because of the huge size of the whole machine and the high production cost. Therefore, it is very necessary to study the stereoscopic projection display technology based on polarization technology, and to seek a stereoscopic projection display technology suitable for multiple people to watch at the same time, convenient to move, and low in price.

Liquid Crystal on Silicon - LCoS (Liquid Crystal on Silicon) microdisplay chip is a reflective LCD (Liquid Crystal Display), so like LCD, LCoS microdisplay chip only modulates polarized light, and the modulated outgoing light is also polarized Light. The LCoS projection light machine composed of LCoS microdisplay chip and polarization beam splitting device has the advantages of high light efficiency, good resolution, high contrast, low cost, small size and easy mass production, etc., but this LCoS projection light machine can only project Ordinary plane images do not have the function of projecting stereoscopic images.

the

Contents of the invention

Technical problem: The purpose of the present invention is to provide a liquid crystal on silicon stereoscopic projection light machine, which can realize the stereoscopic display of color images, and has the characteristics of simple structure, high contrast, high light utilization rate, and low cost.

A further object of the present invention is to provide an optical machine capable of switching between three-dimensional color projection display and planar two-dimensional color projection display.

Technical solution: The liquid crystal-on-silicon stereoscopic projection optical machine of the present invention includes a light source, a first polarization beam splitting device, a second polarization beam splitting device, a first liquid crystal on silicon base microdisplay chip, a second liquid crystal on silicon base microdisplay chip, and a half-wave plate , a first reflection mirror with a quarter-wave plate attached to its surface, a second reflection mirror with a quarter-wave plate attached to its surface, and a projection objective lens. in,

The central optical axis of the light source, the first polarizing beam splitting device, the half-wave plate, the second polarizing beam splitting device, and the projection objective lens are sequentially arranged on the same central optical axis, that is, the half-wave plate is arranged on the first polarizing beam splitting device, the second polarizing beam splitting device, and the second polarizing beam splitting device. Between the devices, the light source is located at the incident surface of the first polarization beam splitting device, and the projection objective lens is located at the exit surface of the second polarization beam splitting device; The two sides of the central optical axis are opposite to each other in parallel; the second liquid crystal on silicon microdisplay chip and the second mirror are located on both sides of the central optical axis in the second polarization beam splitting device and are parallel to each other; the first liquid crystal on silicon microdisplay The display chip and the second reflector are located on the same side, and the first reflector and the second silicon-based liquid crystal microdisplay chip are located on the other side.

The first liquid crystal on silicon microdisplay chip and the second liquid crystal on silicon microdisplay chip are color filter type liquid crystal on silicon microdisplay chips.

The first polarizing beam splitting device and the second polarizing beam splitting device are stacked and placed in parallel, and the first polarizing beam splitting film is parallel to the second polarizing beam splitting film.

Quarter-wave plates are pasted on the surfaces of the first reflector and the second reflector.

The first liquid crystal on silicon microdisplay chip and the first mirror with a quarter-wave plate attached to the surface are respectively located on two parallel and opposite sides of the first polarization beam splitting device, and a quarter-wave plate is attached to the surface. The first reflection mirror of the sheet can firstly receive the light source light reflected from the first polarization splitting film.

The first liquid crystal on silicon microdisplay chip and the second liquid crystal on silicon microdisplay chip are color filter type liquid crystal on silicon microdisplay chips with the same base color.

The stereoscopic projection optical machine also includes a position adjustment mechanism, which is used to fine-tune the positions of the first liquid crystal on silicon micro-display chip and the second liquid crystal-on-silicon micro-display chip when the optical machine is used for ordinary flat projection display. Make the imaging positions of the corresponding pixels of the micro-display chips overlap.

The light source is a white monochromatic light source or a light source composed of red, green and blue LED chip groups.

The light source is a laser light source, and the laser light source is a white monochromatic light source or a light source composed of red, green and blue laser lights.

The first polarization beam splitting device and the second polarization beam splitting device are wire grid polarization beam splitters or polarization beam splitter prisms.

When the input image information of the two micro-display chips corresponds to the angle of view of the left and right eyes respectively, the LCoS stereo projection light engine of the present invention can realize color stereo projection display; when the input image information of the two micro-display chips is the same, Then the two-dimensional plane color projection display can be realized.

In the silicon-based liquid crystal stereoscopic projector of the present invention, the alignment positions of two LCoS microdisplay chips, two reflectors with quarter-wave plates attached to their surfaces, polarization beam splitters, and half-wave plates must ensure that the light incident on the LCoS micro The imaging light rays reflected on the display chip and from the LCoS microdisplay chip respectively pass through the polarization beam splitting film twice, and one is reflected and the other is transmitted. In order to ensure the contrast balance of the finally emitted S-linearly polarized light and P-linearly polarized light images.

In the liquid crystal-on-silicon three-dimensional projection optical machine of the present invention, a quarter-wave plate is pasted on the surface of the LCoS micro-display chip, which can further increase the contrast of the image and improve the image quality.

Beneficial effects: the present invention has the following beneficial effects: Compared with the background technology, the present invention mainly uses two LCoS microdisplay chips and two polarization splitting devices to realize the color stereoscopic display of images. The light-mechanical structure is simple, the cost is low, and the image quality is good. And it can conveniently switch freely between the color three-dimensional display mode and the two-dimensional plane display mode.

the

Description of drawings

Fig. 1 is a schematic diagram of an embodiment of the present invention.

Fig. 2 is a schematic diagram of another embodiment of the present invention.

In the figure, there are: light source 1, first polarization beam splitting device 2, first polarization beam splitting film 22, first reflector 3, first silicon-based liquid crystal microdisplay chip 4, half-wave plate 5, second polarization beam splitting device 6, the first Two polarization splitting films 23 , a second liquid crystal on silicon microdisplay chip 7 , a second mirror 8 , a projection objective lens 9 , a first quarter wave plate 10 , and a second quarter wave plate 11 .

First path first line S polarized light 13, first path second line P polarized light 19, first path third line S polarized light 20, first path fourth line P polarized light 21; second path first line P polarized light Light 14 , second path second line S polarized light 15 , second path third line P polarized light 16 , second path fourth line S polarized light 17 , imaging beam 19 .

the

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings, but the description does not limit the content of the present invention.

Fig. 1 is an embodiment of the liquid crystal on silicon stereo projection optical machine of the present invention.

The central optical axes of the light source 1, the first polarizing beam splitting device 2, the half-wave plate 5, the second polarizing beam splitting device 6, and the projection objective lens 9 are sequentially arranged on the same central optical axis, that is, the half-wave plate 5 is arranged on the first polarizing beam splitting Between the device 2 and the second polarization splitting device 6, the light source 1 is located at the incident surface of the first polarization splitting device 2, and the projection objective lens 9 is located at the exit surface of the second polarization splitting device 6; the first liquid crystal on silicon microdisplay chip 4 , the first mirror 3 is located on both sides of the central optical axis in the first polarization beam splitting device 2 and is parallel to each other; the second liquid crystal on silicon microdisplay chip 7 and the second mirror 8 are located in the second polarization beam splitting device 6 The two sides of the central optical axis are parallel and opposite; the first liquid crystal-on-silicon micro-display chip 4 and the second reflector 8 are located on the same side, and the first reflector 3 and the second liquid crystal-on-silicon micro-display chip 7 are located on the other side .

The light source is an LED light source, which can be a white monochromatic light source or a light source composed of red, blue and green LED chipsets. The first liquid crystal on silicon microdisplay chip 4 and the second liquid crystal on silicon microdisplay chip 7 can be described in Chinese patent No. Display chip. The two polarizing beam splitting devices, ie the first polarizing beam splitting device 2 and the second polarizing beam splitting device 6 are stacked and placed in parallel, and the two polarizing beam splitting films, namely the first polarizing beam splitting film 22 and the second polarizing beam splitting film 23 are parallel. The half-wave plate 5 is located at the joint surface of the two polarization splitting devices. The first mirror 3 with a quarter-wave plate attached to the surface and the first LCoS microdisplay chip 4 are respectively located on the two sides adjacent to the light-emitting surface of the first polarization beam splitting device 2, and the mirror 3 can first receive the polarized beam splitting device. 2 Reflected light from the light source. The second mirror 8 with a quarter-wave plate attached to the surface and the second LCoS microdisplay chip 7 are respectively located on the two sides adjacent to the light exit surface of the second polarization splitting device 6, and the first liquid crystal on silicon microdisplay chip 4 and the second liquid crystal on silicon microdisplay chip 7 are respectively located on both sides of the light splitting device. Stereoscopic image information corresponding to the viewing angles of the left and right eyes may be respectively input.

When the illumination light 12 from the light source is incident on the polarization beam splitting device 2 , the light is reflected and transmitted at the polarization beam splitting film 22 and is divided into two paths (dotted line and realization part in the figure) . The reflected first-path first-line S-linearly polarized light 13 is incident on the first reflector 3, and after the direction is rotated by 90°, it is reflected from the first reflector 3 back to the first polarization beam-splitting device 2, thereby being transmitted through the polarization beam-splitting film and incident to the first LCoS micro-display chip 4 . After the second linear P-polarized light 19 of the first path incident on the first LCoS microdisplay chip 4 is modulated, part of the linearly polarized light with color image information is reflected and the polarization direction is rotated by 90° to be incident on the polarization beam splitting device 2 again. , so that it is reflected out of the spectroscopic device by the polarizing spectroscopic film. The third line S polarized light 20 of the first path exits from the polarization beam splitting device 2 and then rotates by 90° in the direction of the half wave plate 5 (becomes the fourth line P polarized light 21 of the first path ) enters the polarization beam splitting device 6 and transmits its polarization The beam splitting film, finally enters the projection objective lens.

The second-path first-line P-polarized light 14 transmitted through the polarization-splitting film 22 is rotated by 90° through the half-wave plate 5 (becomes the second-path second-line S-polarized light 15 ) and enters the polarization-splitting device 6 . The second line S polarized light 15 of the second path is reflected by the polarization splitting film 23 of the spectroscopic device 6 onto the second LCoS microdisplay chip 7, and part of the linearly polarized light with color image information after modulation is reflected back to the second polarized spectroscopic device 6 and the direction is rotated by 90°, the third line P polarized light 16 of the second path of the beam is transmitted through the polarization splitting film and is incident on the second reflector 8 with a quarter-wave plate attached to the surface, and the reflector 8 reflects it back into polarization The beam splitting device 6 rotates the direction by 90° to become the fourth line S linearly polarized light 17 on the second path, which is reflected by the polarizing beam splitting film and exits the second polarizing beam splitting device 6 .

Finally , the fourth-line S-polarized light 17 of the second path and the fourth-line P-polarized light 21 of the first path emitted from the polarization beam splitting device are synthesized into an imaging beam 18 and then enlarged and imaged by the projection objective lens for projection display. In this way, part of the projected image light is P linearly polarized light modulated by the first LCoS microdisplay chip 4 , and the other part is S linearly polarized light modulated by the second LCoS microdisplay chip 7 . If the viewer wears polarized glasses made of polarizers whose polarization directions are perpendicular to each other, and the directions of the lenses are parallel to the P-line polarized light and the S-line polarized light respectively, the viewer's two eyes can only see the P-line polarized light respectively. Light image and S linearly polarized light image. When the first liquid crystal on silicon microdisplay chip 4 and the second liquid crystal on silicon microdisplay chip 7 input the stereoscopic image information corresponding to the angle of view of the left and right eyes, the left and right eyes of the viewer can respectively see the images corresponding to the angle of view , thus forming stereoscopic vision.

When the image information on the two LCoS micro-display chips is exactly the same, the positions of the two LCoS micro-display chips can be adjusted by a position adjustment mechanism (not shown), so that the projection images of the corresponding pixels of the two chips are completely overlapped. When initially assembled, if the projected images of the corresponding pixels of the two chips are completely overlapped, the positions of the two chips can be fixed without an adjustment device. At this time, the viewer can watch the two-dimensional plane display image without wearing glasses.

Since the silicon-based liquid crystal stereoscopic projection light machine does not need a pre-polarization device, different polarized lights are utilized, so the optical efficiency of the system can be effectively improved.

For the polarized spectroscopic film of the existing conventional polarized spectroscopic device, the extinction ratio of the transmitted light and reflected light is different, usually the extinction ratio of the transmitted light (can be greater than 1000:1) is much greater than the extinction ratio of the reflected light (approx. dozens to one). In the present invention, in order to improve the contrast of image, the imaging light incident on the LCoS microdisplay chip and reflected from the LCoS microdisplay chip are respectively passed through the polarization beam splitting film twice, and once for reflection and once for transmission, so that the contrast of the image is greatly improved. It improves and ensures that the extinction ratio of the two linearly polarized lights finally emitted is very balanced, so that the overall extinction ratio of the combined imaging beam reaches the best.

In addition, since the incident light of the light source is not completely parallel, the wide-angle incident light and oblique light will produce a geometric rotation of the polarization state on the polarization beam splitter film. In order to correct this effect, a quarter wave can also be pasted on the surface of the LCoS microdisplay chip sheet, to ensure the contrast of the system, as shown in Figure 2, an embodiment of the liquid crystal on silicon stereoscopic projection light machine of the present invention.

The device and method according to the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, it is clear to those skilled in the art that various modifications and changes can be made thereto without departing from the spirit and scope of the present invention. Accordingly, the detailed description of the embodiments and the drawings should be regarded as illustrative rather than restrictive. The scope of the present invention should be defined by the claims.

Claims (10)

1. A liquid crystal on silicon stereoscopic projector, comprising a light source (1), a first polarization splitting device (2), a second polarization splitting device (6), a first liquid crystal on silicon microdisplay chip (4), a second Silicon-based liquid crystal microdisplay chip (7), half-wave plate (5), first mirror (3), second mirror (8), projection objective lens (9), characterized in that: The central optical axes of the light source (1), the first polarizing beam splitting device (2), the half-wave plate (5), the second polarizing beam splitting device (6), and the projection objective lens (9) are sequentially arranged on the same central optical axis, namely The half-wave plate (5) is arranged between the first polarizing beam splitting device (2) and the second polarizing beam splitting device (6), the light source (1) is located at the incident surface of the first polarizing beam splitting device (2), and the projection objective lens (9 ) is located at the exit surface of the second polarization beam splitting device (6); the first liquid crystal on silicon microdisplay chip (4) and the first mirror (3) are located at the center optical axis of the first polarization beam splitting device (2) The two sides are parallel and opposite; the second silicon-based liquid crystal microdisplay chip (7) and the second mirror (8) are located on both sides of the central optical axis in the second polarization beam splitting device (6) and are parallel and opposite; the first The silicon-based liquid crystal microdisplay chip (4) and the second reflector (8) are located on the same side, and the first reflector (3) and the second silicon-based liquid crystal microdisplay chip (7) are located on the other side. 2. The liquid crystal on silicon stereoscopic projection optical machine according to claim 1, characterized in that, the first liquid crystal on silicon microdisplay chip (4) and the second liquid crystal on silicon microdisplay chip (7) are color filter Type liquid crystal on silicon microdisplay chip. 3. The liquid crystal-on-silicon stereoscopic projector according to claim 1, characterized in that the first polarizing beam splitting device (2) and the second polarizing beam splitting device (6) are stacked and placed in parallel, and the first polarizing beam splitting film ( 22) parallel to the second polarizing beam splitting film (23). 4. The liquid crystal-on-silicon stereoscopic projection optical machine according to claim 1, characterized in that a quarter-wave plate is attached to the surface of the first reflector (3) and the second reflector (8). 5. The liquid crystal on silicon stereoscopic projection optical machine according to claim 1, characterized in that the first liquid crystal on silicon microdisplay chip (4) and the first mirror (3) with a quarter wave plate attached to the surface ) are respectively located on two parallel and opposite sides of the first polarization beam splitting device (2), and the first mirror (3) with a quarter-wave plate attached to the surface can first receive light from the first polarization beam splitter film (22) Reflected source light (13). 6. The liquid crystal on silicon stereoscopic projection optical machine according to claim 1 or 2, characterized in that the first liquid crystal on silicon microdisplay chip (4) and the second liquid crystal on silicon microdisplay chip (7) are of the same primary color Filter type liquid crystal on silicon microdisplay chip. 7. The liquid crystal-on-silicon stereoscopic projection optical machine as claimed in claim 1 or 2, characterized in that the stereoscopic projection optical machine also includes a position adjustment mechanism for fine-tuning when the optical machine is used for ordinary flat projection display. The first liquid crystal on silicon micro-display chip (4) and the second liquid crystal on silicon micro-display chip (7) are positioned such that the imaging positions of corresponding pixels of the micro-display chips coincide. 8. The liquid crystal-on-silicon three-dimensional projection light machine according to claim 1, characterized in that the light source (1) is a white monochromatic light source or a light source composed of red, green and blue LED chipsets. 9. The liquid crystal on silicon stereoscopic projection machine according to claim 1, characterized in that the light source (1) is a laser light source, and the laser light source is a white monochromatic light source or a red, green and blue three-color light source A light source consisting of laser lights. 10. The liquid crystal on silicon stereoscopic projector according to claim 1 or 3, characterized in that the first polarization beam splitter (2) and the second polarization beam splitter (6) are wire grid polarization beam splitters or polarization beam splitters prism.

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