TW548473B - Optical engine of reflective type liquid crystal projector - Google Patents

Abstract

An optical engine of reflective type liquid crystal projector is disclosed, wherein an S-polarized incident light comprising the first to the third color lights is utilized to project an image onto an image-forming position, which mainly comprises: a dichroic mirror, 3 polarization beam splitters, 3 liquid crystal plates, a relay system and a light-combining device, wherein the polarization beam splitter of the second color light can also function as a dichroic mirror by using its narrow-frequency characteristic to reduce the number of optical devices employed; the relay system can guide the third color light to the liquid crystal plate of the third color, and maintains the light shape, optical uniformity and incident angle. Thus, the volume of the optical engine can be reduced, and the aperture ratio and resolution can maintain to a certain degree toward the tendency of reducing the volume. It can be manufactured by the current technology with low cost.

Description

548473 5. Description of the invention ⑴ [Scope of application of the invention] The present invention provides an optical engine, which is used in a reflective liquid crystal projection display. A light source is provided by an illumination system, and the image is projected by a projection lens through the optical engine. The image is displayed on the screen. [Background of the Invention] Since the world's first liquid crystal projection display (Liquid Crystal Projection Display) was successfully mass-produced in 1989, it has successfully solved many problems in engineering technology, such as the use of optical lens array integrators or glass cylinders. An integrator (Optical Lens Array Integrator or Glass Rod Integrator) is used to solve the problems of uneven brightness of the lighting source and the loss of efficiency of Form Transformation between the lighting source being axisymmetric and the lighting object being rectangular; using polarization conversion technology (Polarization Conversion Technique) to solve the problem of light efficiency loss and overheating of polarizers caused by polarized light absorption; as for the resolution problem, high temperature poly-crystalline liquid crystal display (High Temperature Poly-TFT LCD) is used to achieve high Density (1 · 3Π, 1024x768), high resolution (VGA, SVGA, XGA), and high image quality objectives (Contrast Ratio > 200: 1). To this day, the LCD projection display has been able to achieve a light efficiency of 010 m / W (luminous flux wheel out / application of light source wattage), which is already in almost all displays (such as CRT, PDP, LED, FEL, etc.) The most efficient. At the present stage, the technology of liquid crystal projection displays is moving towards higher brightness (> 12 00 AN SI lumens), higher resolution (> 1 2 0 0 x 1 0 2 4), and lighter and smaller directions. .

548473 V. Description of the invention (2) There are two types of traditional liquid crystal projection display systems: single-chip type and three-chip type. The liquid crystal panels used are all transmissive, but in the case of higher and higher resolution, f uses the same The size of the liquid crystal panel must be changed from transmissive to reflective to increase the aperture ratio of the liquid crystal panel. This is because the reflective liquid crystal panel is manufactured by covering its thin-film transistor (TFT) under the reflective metal layer, because the reflective metal layer itself can block light, and it is not necessary to make a light-shielding black matrix (Black Matrix). It prevents the TFT from leaking electricity due to light. Therefore, the area through which light can pass through each day is larger than that of the transmissive type, so the reflective liquid crystal panel has a better aperture ratio. However, although the aperture ratio is increased, the optical system of the reflective liquid crystal optical projection display is more complicated than the transmissive system. The biggest difference is the LCD panel surface in the reflective liquid crystal optical projection system, which requires polarization polarization beam splitter 10 (Polarizati〇I1 Beain Splitter, PBS) to separate the incident light and the outgoing light, that is, the incident light passes through the polarization After splitting the coated surface 101 of 稜鏡, the light illuminating the liquid crystal panel 20 (LCD) is a certain f-direction, for example, p-polarized light, and the p-polarized light passes through the liquid crystal panel 20 and is intermodulated. After being reflected, the polarized direction of the polarized light will be changed to S polarized light B 2, and then reflected by the polarized beam splitter 稜鏡 10 and projected onto the screen (not shown). As for the daylight reflected light that has not been modulated by the liquid crystal panel 20, the original polarization direction is retained, that is, the P polarized light B1, which will penetrate the polarized light splitting and return to the light source (such as " As shown in Figure 1 ", the S polarization is represented by a small dot, and the p polarization is represented by the front head). In a reflective liquid crystal display system, in order to avoid color distortion, the polarization beam splitter needs to be in the entire visible light region (400nm ~ 〇〇ηιη).

548473 V. Description of the invention (3) Polarization (Ext incti Generally speaking, the reflective liquid distance caused by the characteristics of such polarized light-emitting liquid crystals should be used when there is a good sub-contrast. In the lens-shadow system, the transmissive liquid crystal is displayed. The light effect is in line with the system's spectroscopic on Ra ti (the main crystal projector with a large-angle spectroscopic display limited to JF will be shown in a certain display with the LCD design. The system is also the requirement of S polarized light and P polarized light. It is important that the 7-blade light needs to be able to maintain a certain extinction ratio of incidence in the first place (>), without limiting the system. Incident light can improve the efficiency of light collection. The design of a component is very difficult. In terms of polarization polarization splitting, I ^ 通 # is the opposite component. In addition, the use of polarization The projection lens must also have ~ 77 light edges, and these components can be placed between the ^^ ^; the back focus is more complicated 'especially if you want a relatively large magnification for a long distance of t μ for the lens, the lens The design must conform to ϊ ΐ 'This pair of essays is quite sleepy A conventional reflective liquid crystal projection display system such as "Figure 2 includes: light source device 30, front polarizer 3 1, polarized polarizer 1 no '10, two-color 稜鏡 4 0 (X- Cube), LCD panels 21, 22, & head 60. The light source device 30 emits non-polarized aurora, which is converted into linear polarized light by a front polarized lens projection projection. This linear polarized light is polarized and splits $ 1. $ 极 射到 双色 稜鏡 40, Bicolor 稜鏡 4 0 reflects linearly polarized white ^, light and blue light, so that green light is transmitted, and green light, blue light, and red light are respectively projected onto the green liquid crystal panel 21, The red liquid crystal panel 22 and the blue liquid crystal panel & I crystal panel 2 1, 2, 2 and 2 3 respectively modulate the polarization of the incident light according to the green, red, and blue scenes. Image 1 After the modulation, Green, red and blue / light =

548473 V. Description of the invention (4) 2 The mirror 40 penetrates the two-color 稜鏡 40 to the polarized polarizer along the original incident path, and then the projection lens 60 projects the image onto the screen 61. The conventional reflective liquid crystal projection system has the following shortcomings: 1. Because the incident light is s-polarized light, and the outgoing light is ρ-polarized light, and s-polarized light and P-polarized light are compared to the two-color 稜鏡 4 〇, Its frequency spectrum will be shifted, causing color deviation. 2 · Because the polarization beam splitting 稜鏡 丨 〇 can be polarized into the entire visible light range, it must be broadband (B r 〇a ^ — band), which is more complicated and expensive to produce of. 3. Under the requirements of local extinction ratio and wideband polarized beam splitting, the numerical aperture (Numerical Aperture, NA) value of polarized beam splitter prism 10 is very high, and the relative light collection efficiency of the system is also reduced. In order to solve the problems of the conventional technology mentioned above, another structure as shown in Fig. 3 is proposed. This reflective liquid crystal projection display system mainly includes a white light incident light 301, dichroic mirrors 41, 42, 43 and 32a, 3 2b, green, red, and blue liquid crystal panels 21, 2 2, 2 3, and green. The light, red light, and meal light polarized beam splitting prisms 11, 12, 13, a light combining device 50 (X-Cube), and a projection lens 60. The method is to first use the dichroic mirrors 41, 42, 43 to separate the three primary colors from the white light incident light 301, and then use three polarization polarization beam splitters 11, 1, 2, 1 3 to process the three primary colors (R , G, B), so that the polarization beam splitter 稜鏡 1 1, 1 2, 1 3 only needs a narrow frequency ', and the numerical aperture value of the polarization beam splitter 稜鏡 1 1, 1, 2, 13 can be increased. However, in the previous case, in addition to the two polarization polarization beamsplitters and three more dichroic mirrors than the previous system, this system solved the problem described previously.

Page 7 548473 V. Description of the invention (5) The problems of the conventional technology are lacking, but the system also becomes more complicated and huge. [Objective and Summary of the Invention] The main object of the present invention is to provide an optical engine of a reflective liquid crystal projection display, which uses a polarized beam splitter and has the function of a dichroic mirror, which can reduce the use of optical components, and Integrable (Compact), and under the trend of decreasing volume, the aperture ratio and resolution of the polarization beam splitter can still be maintained to a certain degree, and it can be manufactured according to the existing technology with low manufacturing cost. According to the optical engine of the reflective liquid crystal projection display disclosed by the present invention, He uses the S-polarized incident light containing the first to third color lights to project an image to an imaging position, including: a dichroic mirror, used for The first color light of the incident light is reflected, and the second color light and the third color light of the incident light are transmitted. A first color light modulation unit is configured to change the first color light reflected from the dichroic mirror to a band. The light with the first color light image signal; a second color light modulation unit that changes the second color light penetrating the dichroic mirror to the light with the second color light image signal and makes the third color penetrating third The color light is guided to the other direction; an image extension system is configured in the optical path of the incident light to generate an image extension effect on the third color light penetrating the second color light modulation unit; a third color light modulation unit , Which changes the third color light from the extended image system into light with a third color light image signal; and a light combining device for changing the first color light, the second color light, and the third color light image signal Light to a projection lens

548473 V. Description of the invention (6) Wherein, each color light modulation unit includes a liquid crystal panel corresponding to the color light and a polarization polarization beam splitting prism, and each polarization polarization beam splitting prism is used to reflect the corresponding incident color light to The corresponding liquid crystal panel is reflected and adjusted to form a light with the color light image signal, and then penetrates the polarized beam splitter. The present invention further proposes three embodiments of the image extension system. The image extension system guides the third color light to the third color liquid crystal panel, and can maintain the light shape, light uniformity, and incident angle of the light. The detailed content and technology of the present invention are described below with reference to the drawings:

[Brief description of the figure] Figure 1 is a schematic diagram of the matching effect of a polarized beam splitter and a reflective liquid crystal panel. FIG. 2 is a schematic diagram of a conventional reflective liquid crystal projection display system. Fig. 3 is a schematic diagram of a reflective liquid crystal projection display system of the same light path as in the previous case. Fig. 4 is a schematic diagram of a reflective liquid crystal projection display system of the present invention. FIG. 5A is a schematic structural diagram of a first image extending system according to the present invention. Figure 5B is an enlarged view of the "Image 5A" extended image system.

FIG. 6 is a schematic structural diagram of a second image extending system according to the present invention. FIG. 7 is a schematic structural diagram of a third image extending system according to the present invention. FIG. 8A is a side view of the “a” in FIG. 7. Figure 8B is a side view of b of "Figure 7".

Page 9 548473 The reflection is to reflect the opposite light and the red light will pass through the light of the signal, including a green light through a reflective liquid crystal projection display optical guide projection display, and the reflective liquid crystal projection system and 2. lighting system There are two parts; and 1. The optical path system such as 1. equal optical path system and 2. extended image system The optical path system such as the above-mentioned "Figure 3" structure of the system. "" Is a schematic diagram of the structure of the anti-engine disclosed in the present invention, using three primary colors of incident light 3 02 to project the image to the imaging V. Description of the invention (7) [Detailed description of the invention] The engine disclosed according to the present invention It is used in reflective liquid crystal display including: 1. Projection light path to distinguish, can be divided into two types (Relay System). The present invention is to use the extension. Please first refer to "Figure 4 S-polarized polarization position of the optical light guide (R, G, B) of a projection projection display, including: a dichroic mirror 4 4 for emitting light. The green light and blue light and red light modulation unit are equipped with a red light image signal, a red liquid crystal panel 22, and the red light is polarized, modulated and vice versa. The light ^ then penetrates a green light modulation The unit is a green light image which is guided to the other direction by a green liquid crystal panel 21 and the red light of the green light incident light 302 of the dichroic mirror 44 and penetrates into it; Lines include: light polarizing beam splitting prism 15 'red light prism 15 reflecting to red liquid crystal panel 2 2 to form a polarizing beam splitter with red light image signal 15; green light passing through dichroic mirror 44 Modified into a band, and the blue light penetrating the dichroic mirror 44 includes: light polarization polarization beam splitting 稜鏡 1 4 and green light polarization polarization splitting 稜鏡 1 4 reflection

Page 10 548473 V. Description of the invention (8) ------- Go to the green liquid crystal panel 21, which is modulated and has the light signal with green image signal, and then pass through ϊ = ί to form a zone ^ Λ- -A green polarized beam splitter k-mirror 14 and a blue polarized beam splitter 穿透 14 that penetrates the dichroic mirror 44; a direct tooth penetrating lens; a first extended image system 70 configured with incident light 3 2 The optical path is generated by the blue light penetrating the green light modulation unit—a ^ tone that changes the blue light tone from the extended image system 70 to a V-monitored light signal, including: ^ fLCD panel M and A blue light polarization beam splitter 稜鏡 16, which is from 糸, is reflected by the blue light polarization beam splitting prism 16 onto the monitor color liquid crystal panel 23. After being modulated and reflected, a T image signal with blue light is formed. The light then penetrates the blue polarized polarization beam splitter 16; and, the device 50 is used to combine the light with red, green, and blue image signals to the projection lens 60. This architecture can be divided into the following two unique parts: 1 · Using green light polarization polarization beam splitting 稜鏡 丨 4 also serves as a blue and green light dichroic dichroic mirror: from the description of "Figure 1", the polarization polarization beam splitting edge The role of the mirror 丨 〇 is to separate different types of polarized light (p-polarized light and S-polarized light). However, in order to find the numerical aperture value of a higher polarization polarization beam 稜鏡 丨 〇, It is necessary to use a narrow-band (N arr 0w — band) polarized beam splitting chirp. For example, the green polarization polarization beam splitter 稜鏡 4 only reflects the S-polarized light in the vicinity of the green light band (500 nm ~ 5 7 0 nm), and the P-polarized light in this band and any type of other wavelengths. Both polarized lights can be worn

Page 548473

V. Description of the invention (9) Thorough. Therefore, the frequency polarization polarization beam splitting can be changed without changing any component specifications. As the blue-green light or red-green light splitting bicolor picture, the first beam splitting dichroic mirror 44 can polarize 8 red light first. After the reflection is separated, the penetrating S blue-green polarized light enters the green light polarized beam splitter 稜鏡 14, and the green light is reflected on the green liquid crystal panel (UCD panel, etc.), and the blue light continues. The green polarized beam splitter 稜鏡 14 is penetrated and enters the image extension system 70. In this way, a simple optical path can be used to simplify the beam splitting system. 0

In addition, it also includes a condenser 33a located in the optical light path and disposed between the dichroic mirror 44 and the red light modulating unit, and another condenser 3 3 b is disposed between the dichroic mirror 44 and the green light modulating unit so that The light shape projected on the liquid crystal panels 22, 21 has the best effect. 2 · Relay system 70 (Relay system): After the e-beam leaves the green light polarized beam splitter 稜鏡 14, there will be an optimal liquid-day plate placement position, which is called the LCD panel virtual position 2 4 (V irtua 1 LCD Panj 1 Po), and then the energy will be dissipated after crossing this position, so the j light needs to be guided by the image extension system 70 to the liquid crystal panel's virtual position 2 4 to the blue liquid i plate 23. The requirements of the general image extension system 70 are as follows: (1) The light shape magnification of the light collection area is 1.

\ 2) Maintain the angle of light incident on the LCD panel. 3) Maintain the uniformity of the light beam. Therefore, in order to achieve the above requirements, the following several innovative architectures are proposed:

Page 12 548473 V. Description of the invention (ίο) I. Gu idi ng Rod extended image system: As shown in "Figure 5", glass is known and used to uniformize the distribution of light energy and dimension A / Glass Rod) This technology can be used, and this technology is to use the angle of light on the slope, which is already known. So if you use four mirrors to directly form the principle of total reflection in a column, instead of cutting the glass column directly, use = plane as The same effect can be achieved by the reflection of a square hollow square pillar. Ben's method 'makes light use the principle of specular reflection in it, and makes ^ = 70 system's design concept. The base glass square column makes two 90-degree turns to empty the square column 71 or-- The second ninety-degree turn is the use of a piece of second-private 711 knot a 丄 丄 姑 姑 & the first nine-way ninety-five degree mirror is a 45-degree angle mirror. The polarized light is reflected on the surface 161. Such an extended image system 70 not only does not need a special 2, film design, but also can improve the uniformity of the blue light, as well as improve the distortion of the light shape caused by the lens, and improve the first benefit. "Figure 5B" is the big picture of the "Picture 5 A" extended image system 70. II · The first three-lens (Three Lens) image extension system: No: Figure 6 "No, because the reflective LCD panel lighting system requires a longer working distance, it is also more complicated in design . In order to obtain a better light shape on the f meter, it is necessary to try to make the length of the image extension system 70 appropriate. This method uses a polarized beam splitter 7 2 and a half-wavelength Q75 (HWP), a quarter-wavelength plate 74 (QWp), and a reflector 73 to achieve an extended optical system. The length does not increase the size of the system. After the incident monitor light leaves the green polarized beam splitter 稜鏡 4, it enters

Page 13 548473 V. Description of the invention (11) Into the extended image system 70, the blue light is reflected by the light beam 72, and the light is broken—a polarization polarization wavelength of 45 degrees between the film and the optical axis. The plate 7 4 is reflected twice by the reflector 7 3, and then collides with 彳 4 after passing through the four beams for a second time, turning into a p-polarized blue light, so when the wavelength plate 75 is configured; Will penetrate. Half-P polarized polarization is obtained by # to, before the polarized beam splitting prism 16 ′, and Λ / which is to be entered is converted into an S polarized blue light. r Γ Η also includes three condensers 76a, 76b, and 76c with a radius of III. Same, as shown in the figure. 76d (22, 22)) 'are located at the entrance of the extended image system 70, the polarization polarization γ 5? ^, Between the quarter wave plate 74, and the polarization polarization beam splitting "7 knives ^ one Between the wavelength plates 75, the optical design can be used to obtain the best curvature on the liquid crystal panel 23 due to its curvature of three. The second Three Lens image extension system: as shown in Figure 7 ", The basic spirit of this method is the same as that of the previous method. The method of extending the optical path is changed to a three-dimensional form, and "8A and 8B are the" Figure 7 "side views in two different directions, a side and b side. An X in the circle indicates that the light enters the paper X and the blue light leaves the green light polarized beam splitter 稜鏡 14. After passing through the condenser lens, the light is reflected upward by the first reflecting mirror 73a, and the light beam hits the second reflecting mirror 7 After 3 b, turn to the condenser 7 6 e, and then collide with the third reflector 7 3c ', then turn to the condenser 76 76, and finally enter the blue polarization polarization beam splitting prism 1 6'. The three-dimensional structure can save more space in the system design. use. The use of the red light, the green light, and the blue light and the corresponding optical elements' of the present invention are not limited to the positions of the above-mentioned embodiments, and they can also be arranged and combined to form the order of the three primary colors of light and the corresponding optical elements.

Page 14 548473 V. Description of the invention (12) [Effects of the invention] According to the optical engine of the reflective projection display disclosed by the present invention, the effects are as follows: 1) The use of a polarization polarization beam splitting prism (PBS) is dual color The function of the mirror can reduce the use of optical components, such as dichroic mirrors and reflectors, and also reduce manufacturing costs. 2 · Propose a novel structure and simplify the system to reduce the volume of the optical engine (Opt ical-Engine), which is about one-third smaller than the general optical system, so the volume can be more compact (Compact),

And the optical system is easy to adjust and correct. 3. Xin J. With the optical engine proposed by the present invention, under the trend of smaller and smaller volume requirements, the aperture ratio and resolution of the polarization beam splitter can still be maintained to a certain degree, and the manufacturing cost can be reduced. 4. The use of the existing mature semiconductor manufacturing process and the increasingly mature liquid crystal packaging technology can achieve the purpose of using the optical engine of the reflective projection display. Although the present invention is disclosed in the foregoing preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and retouching without departing from the spirit and scope of the present invention. The scope of protection of the invention shall be determined by the scope of the attached patent application.

[Illustration of Symbols] 10 Polarized Beamsplitter 稜鏡 10 1 Coating Surface 11 Green Polarized Beamsplitter Prism

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V. Description of the invention (13) 12 Red light polarized light splitting 稜鏡 13 Blue light polarized light splitting 稜鏡 14 Green light polarized light splitting 稜鏡 15 Red light polarized light splitting 稜鏡 16 Blue light polarized light splitting 稜鏡161 Reflective surface 20 Liquid crystal panel 21 Green liquid crystal panel 22 Red liquid crystal panel 23 Blue liquid crystal panel 24 Liquid crystal panel virtual position 30 Light source device 30 1 White light incident light 302 S polarized incident light 31 Front polarizers 32a, 32b reflection Mirror 3 3a ', 3 3b, 33c Condenser 40 Double-color prism 41 Double-color mirror 42 Double-color mirror 43 Double-color mirror 44 Double-color mirror 50 Light combining device 60 Projection lens Page 16 548473 V. Description of the invention (14) 6 1 Screen 70 Extending system 7 1 Hollow square pillar 71 1 Reflector 72 Polarizing beam splitting prism 73 Reflector 73a First reflector 73b Second reflector 73c Third reflector 74 Quarter wave plate 75 Half Wavelength plates 76a, 76b, 76c, 76d, 76e, 76f Condenser B1 P polarized light B2 S polarized light

Page 17

Claims (1)

548473 Report M 'VI. Shen n Li Yan ...- 1 · An optical engine of a reflective liquid crystal projection display projecting an image to an imaging position using s-polarized incident light containing first to third color light, which At least includes: a dichroic mirror for reflecting the first color light of the incident light and allowing the second color light and the third color light of the incident light to pass through; a first color light modulation unit that reflects the light from The first color light tone of the dichroic mirror is changed to a light with a first color light image signal; a second color light modulation unit changes the second color light tone penetrating the dichroic mirror to a first color light. The light of the two-color light image signal, and directing the third color light penetrating the dichroic mirror to the other direction; An image extension system is configured in the optical path of the incident light to generate an image extension effect on the third color light penetrating the second color light modulation unit; a third color light modulation unit will be from the The third color light of the extended image system is changed to a light with a third color light image signal; and a light combining device is used to change the light with the first color light, the second color light, and the third color light image signal Composite to this imaging position. 2 · The optical engine of the reflective liquid crystal projection display as described in item 1 of the patent application scope, wherein The first color light modulation unit includes a first color liquid crystal panel and a first color light polarization beam splitter. The first color light is reflected to the first color light polarization beam splitter. The first color liquid crystal panel reflects and modulates to form a light with a first color light image signal, and then penetrates the first color light polarization beam splitter; Page 18 548473 6. The scope of the patent application The second color light modulation unit includes a second color liquid crystal panel and a second color polarization polarization beam splitter. The second color light that penetrates the dichroic mirror passes the first color light. The two-color light polarized beam splitter is reflected on the second color liquid crystal panel, and after reflection and modulation, a light with a second color light 'image signal is formed, and then penetrates the second color light polarized beam splitting edge_ Mirror; the third color light penetrating the dichroic mirror directly penetrates the second color light polarization beam splitting prism; and the third color light modulation unit includes a third color liquid crystal panel and a third color light polarization Beam splitter, the third color light from the image extension system is reflected to the third | color LCD panel by the third color polarized beam splitter, after reflection and modulation, a third color is formed ® The light of the light image signal passes through the third color polarization polarization beam splitter. 3. The optical engine of the reflective liquid crystal projection display as described in item 2 of the scope of the patent application, wherein the first color is red, the second color is green, and the third color is blue. 4. The optical engine of the reflective liquid crystal projection display as described in item 2 of the scope of the patent application, wherein the first color is blue, the second color is green, and the third color is red. 5. The optical engine of the reflective liquid crystal projection display as described in item 2 of the scope of patent application, wherein the first color is red, the second color is φ blue, and the third color is green. 6 · The optical engine of the reflective liquid crystal projection display as described in item 2 of the scope of patent application, wherein the first color means green and the second color means · Page 19 548473 • Patent application scope Blue and the third color refer to red. 7 β The optical engine of the reflective liquid crystal projection display according to item 2 of the scope of the patent application, wherein the first color refers to green, the second color refers to red, and the third color refers to blue. 8. The optical engine of the reflective liquid crystal projection display as described in item 2 of the scope of the patent application, wherein the first color is blue, the second color is red, and the third color is green. 9 · Reflective liquid crystal projection display as described in item 1 of the scope of patent application The optical engine further includes a condenser lens located in the optical light path and disposed between the dichroic mirror and the first color light modulation unit. 10 • The optical engine of the reflective liquid crystal projection display as described in item 1 of the patent scope, further comprising a condenser lens located in the optical light path and disposed between the dichroic mirror and the second color light modulation unit. 11 • The optical engine of the reflective liquid crystal projection display as described in item 1 of the scope of the patent application, wherein the image extension system comprises a plurality of reflectors to form a hollow square pillar, so that the third color light reaches the hollow square pillar. Total reflection effect. 1 2 · Reflective liquid crystal projection display as described in item 11 of patent application The optical engine of the indicator, wherein the mirror of the image extension system forms an angle of forty-five degrees with the optical axis of the optical path. 13 • The optical engine of the reflective liquid crystal projection display as described in item 11 of the scope of patent application, wherein the cross-sectional shape of the image extension system is square. 0 Page 20 548473 VI. Application for patent scope 14 • The optical engine of the reflective liquid crystal projection display as described in item 1 of the patent application scope, wherein the image extension system is composed of a glass square pillar, so that the third color light The glass square column achieves the effect of total reflection. 1 5 • The optical engine of a reflective liquid crystal projection display as described in item 1 of the scope of patent application, wherein the image extension system includes a polarization beam splitter, a quarter wave plate, a mirror, and a two For a half-wavelength plate, the third color light is reflected by the polarization beam splitter and then penetrates the quarter-wavelength plate to the mirror, and after being reflected by the mirror, then penetrates the quarter-wavelength plate. The wavelength plate becomes a P-polarized third-color light, and then penetrates the polarization beam splitter and the half-wavelength plate to become an S-polarized third-color light incident on the third-color light modulation unit. 16 • The optical engine of the reflective liquid crystal projection display as described in item 15 of the patent application scope, wherein the image extension system further includes three condensers, which are respectively located in the optical light path, the entrance of the image extension system, the polarization polarization beam splitting Between the prism and the quarter-wave plate, and between the polarization beam splitter and the half-wave plate, the light shape has the best effect. 17 • Reflective LCD projection display as described in item 1 of the patent application The optical engine of the transmitter, wherein the image extension system includes: a first reflector, a second reflector, and a third reflector, and the third color light is reflected by the first reflector and hits the second reflector. After the mirror turns, it collides with the third mirror, and then turns into the third color light modulation. Page 21 548473 6. Scope of patent application XJ0 Early. 1 8 · The optical engine of the reflective liquid crystal display device as described in item 17 of the scope of patent application, wherein the image extension system further includes mirrors, which are respectively located in the optical light path. Between the third reflector and the third mirror and the third color light modulation unit, the light shape is effective. Projection display Three-condensing port, the three reflection best