Projection type image display device

Abstract

The invention provides a projection type image display device. The projection type image display device is composed of a light source optical assembly with a surface light-emitting light source, two LCOS panels, an illumination optical assembly with a polarization separation device and a projection lens. The optical distance from the LCOS panel on one side to the projection lens is equal to the optical distance from the LCOS panel on the other side to the projection lens. The light source optical assembly is close to the surface light-emitting light source, the incident surface is divided into a plurality of planes, the area of the emergent surface of the first optical element is larger than that of the incident surface, and the side surface of the first optical element is an inclined surface; the incident surface is slightly a plane, and the area of the emergent surface opposite to the incident surface is larger than that of the incident surface; and the second optical element of which the connecting side surface between the incident surface and the emergent surface is an inclined surface forms a partial light source optical assembly. Respectively projecting on the LCOS panels on the two sides to form a first projection image and a second projection image, and finally overlapping the first projection image and the second projection image on a screen to realize three-dimensional display.

Description

Technical Field

[0001] The present invention relates to the field of projection technology, and in particular to a projection type image display device. Background Art

[0002] As video signals become higher in resolution, televisions, used as home video receivers, are also moving towards higher resolution and larger screens, from 2K (1920×1080 pixels) to 4K (3840×2160 pixels). In this context, in addition to large televisions, there is a growing demand for compact, lightweight, portable, highly convenient, and low-power high-resolution projection-type image information display devices. However, conventional projection-type image display devices simulate point light sources by combining excitation light from multiple solid-state light sources into a composite excitation light beam. This composite excitation light is then emitted from an excitation light combining unit and split into multiple partial beams by a lens array. These partial beams are then converged by a light-collecting optical component to excite a phosphor, thereby simulating a point light source.

[0003] However, the light sources used in these conventional projection-type image display devices present the following challenges: ① The light source structure is complex and bulky. ② To produce white light, a solid-state light source is required to generate excitation light, and a phosphor is required to generate a mixture of green and red light. Therefore, the overall system luminous efficiency relative to input power depends on the product of the light conversion efficiency of the solid-state light source and the light conversion efficiency of the phosphor for the excitation light, making high efficiency difficult to achieve in principle.

[0004] Liquid crystal displays (LCDs) and digital light processing (DLPs) are the mainstream display elements used in conventional projection-type image display devices. However, while both achieve miniaturization and high resolution, their ability to miniaturize pixel size is limited by their manufacturing methods.

[0005] Furthermore, the image display components used in conventional projection-type image display devices lack technical means to enhance the device's added value beyond improving image quality in terms of resolution and brightness. Consequently, manufacturers produce products with similar performance, leading to price competition. Summary of the Invention

[0006] The present invention aims to solve the problems in the above-mentioned conventional technology and provide a projection type image display device with new functions, using a light source optical component technology of a small and efficient surface light source.

[0007] To achieve the above-mentioned object, the present invention adopts a technical solution: a projection-type image display device comprising a light source optical assembly having a surface-emitting light source, two LCOS panels, an illumination optical assembly having a polarization separation device, and a projection lens; the optical distance from the LCOS panel on one side to the projection lens is equal to the optical distance from the LCOS panel on the other side to the projection lens; The light source optical assembly is close to the surface-emitting light source, the incident surface is divided into multiple planes, the area of ​​the exit surface is larger than the area of ​​the incident surface and the side surface is an inclined surface of the first optical element, and the incident surface is slightly flat and the area of ​​the exit surface opposite to the incident surface is larger than the area of ​​the incident surface, and the connecting side surface between the incident surface and the exit surface is an inclined surface. The second optical element constitutes part of the light source optical assembly and is respectively arranged on the red, green and blue monochromatic surface-emitting LEDs, each monochromatic surface-emitting LED is arranged at a position close to the first optical element, and the exit light of the second optical element is overlapped on the same optical path through the corresponding optical path return mirror and enters the illumination optical assembly; The light beam emitted from the light source optical component passes through the polarization separation device that constitutes the illumination optical component, where the S-polarized light beam is reflected and the P-polarized light beam is transmitted for separation. On one side of the LCOS panel, the S-polarized light beam is modulated to a light intensity and polarization direction that matches the image signal, and is reflected on the reflective surface of the panel. It is then projected through a polarization separation device to form a first magnified projected image. The LCOS panel on the other side transmits a beam of P-polarized light through a polarization separation device, modulates it to a light intensity and polarization direction that matches the image signal, reflects it into an image beam of S-polarized light, and amplifies it through a projection lens to form a second magnified projection image. Finally, the two are superimposed and displayed on the screen.

[0008] Furthermore, in the illumination optical assembly, the optical distance from the LCOS panel on one side to the projection lens is equal to the optical distance from the LCOS panel on the other side to the projection lens.

[0009] The polarization separation device constituting the illumination optical system adopts a reflective polarizing plate as a PS separation filter, and the polarizing plate aligns the metal grid surface with the light source optical component.

[0010] The polarization separation device constituting the illumination optical system is a PS separation prism, wherein the PS separation reflection film is arranged on the inclined surface of the illumination side prism sheet of the PS separation prism, and the prism base material is made of glass material with a refractive index higher than 1.52.

[0011] The invention relates to an illumination optical assembly comprising a light source optical assembly having a surface-emitting light source, two LCOS panels, a polarization separation device, and a projection lens; wherein the optical distance from the LCOS panel on one side to the projection lens is equal to the optical distance from the LCOS panel on the other side to the projection lens; The light source optical assembly is close to the surface emitting light source, and includes a first optical element whose incident surface is divided into multiple planes, whose exit surface is larger than the incident surface and whose side surface is an inclined surface, and a second optical element whose side surface connecting the incident surface and the exit surface is an inclined surface, which constitutes part of the light source optical assembly and is respectively combined with the red, green and blue surface emitting LEDs; Each monochromatic surface-emitting LED is close to the first optical element, and the output light of the second optical element is overlapped on the same optical path through the corresponding optical path returning mirror and enters the lighting optical component. The light beam of the light source optical component is separated into an S-polarized light beam and a P-polarized light beam by the first polarization separation device constituting the lighting component, wherein the S-polarized light beam passes through the glass block for adjusting the optical path length, and then is modulated by the LCOS panel on one side and passes through the first polarization separation device, and is further expanded by the projection lens to form a first expanded projection image, while the P-polarized light beam is separated by the first polarization separation device, passes through the third polarization separation device, and then is modulated by the LCOS panel on the other side, and is then reflected by the third polarization separation device to be an S-polarized light beam, and then is reflected by the oblique surface of the optical path length adjustment glass block, reflected by the second polarization separation device and expanded by the projection lens to form a second expanded projection image, and these two expanded projection images are superimposed on the screen.

[0012] The projection-type image display device comprises a light source optical assembly having a surface-emitting light source, two LCOS panels, a polarization separation device, and a projection lens, wherein the optical distance from the LCOS panel on one side to the projection lens is equal to the optical distance from the LCOS panel on the other side to the projection lens; The light source optical assembly has an optical element for converting divergent light emitted by a surface-emitting light source. The light beam emitted from the light source optical assembly is separated by a PS separation device of the lighting assembly, wherein the S-polarized light beam is reflected and the P-polarized light beam is transmitted; On one side of the LCOS panel, the S-polarized light beam is modulated in terms of light intensity and polarization direction according to the image signal, then reflected on the reflective surface of the panel and passed through the PS separation means. The LCOS panel on the other side separates the P-polarized light beam through the PS separation means, modulates the light intensity and polarization direction according to the image signal, then reflects on the reflective surface of the panel and is reflected as an S-polarized light beam through the PS separation means.

[0013] The optical distance from one LCOS panel of the illumination optical assembly to the projection lens is equal to the optical distance from the other LCOS panel to the projection lens.

[0014] The PS separation device of the illumination optical assembly adopts a reflective polarizing plate with the metal mesh surface facing the light source optical assembly as a PS separation filter.

[0015] The PS separation device of the illumination optical system is a PS separation prism. The PS separation reflective film is arranged on the inclined surface of the prism sheet on one side of the illumination component of the PS separation prism. The prism substrate is made of glass material with a refractive index of 1.52 or more.

[0016] The projection type image display device is composed of a light source optical system with a surface emitting light source, an illumination optical assembly consisting of two LCOS panels and a polarization separation device, and a projection lens; In the illumination optical assembly, the optical distance from one LCOS panel to the projection lens is equal to the optical distance from another LCOS panel to the projection lens; the light source optical assembly includes an optical element that converts divergent light from a surface-emitting light source into a smaller divergent light beam; The first polarization separation device in the illumination optical assembly separates the light source beam by reflecting an S-polarized beam and transmitting a P-polarized beam. The separated S-polarized beam passes through a glass block for adjusting the optical path length and reaches an LCOS panel. On the LCOS panel, the S-polarized beam is modulated in intensity and polarization direction according to the image signal. The S-polarized beam is then reflected by the reflective surface of the panel, passes through the first polarization separation device, passes through the second polarization separation device, and is magnified by the projection lens to form a first magnified projection image. The first PS separation device separates the P light through the P-polarized beam in the light source beam. The third polarization separation device transmits the P-polarized beam. On another LCOS panel, the P-polarized beam modulates the light intensity and polarization direction according to the image signal, and is reflected on the reflective surface of the panel. After being reflected by the third PS separation device as an S-polarized image beam, it is reflected on the inclined surface of the optical path length adjustment glass block. After being reflected by the second polarization separation device, it is magnified by the projection lens to form a second magnified projection image, which is superimposed and displayed on the screen.

[0017] Compared to existing technologies, the present invention offers the following advantages: To achieve a compact, lightweight, portable, low-power, and high-resolution display, it utilizes a compact, high-resolution LCOS (liquid crystal on silicon) as the image display element, enabling miniaturization of the entire illumination optical assembly, including the lighting system. Regarding the light source, the optical component utilizes red, green, and blue monochromatic LEDs (light-emitting diodes) with high light conversion efficiency and a light-reflecting mirror with wavelength-selective reflectivity. This not only efficiently generates the required light but also adjusts the light intensity according to the video signal, thereby achieving higher image quality. Since the amount of light incident on the small image display element is determined by the law of constant beam brightness—that is, the product of the luminous area and divergence angle of a surface-emitting solid-state light source (such as an LED)—new optical components are required to control the luminous area and divergence angle of the LED. This light source optical assembly can collect sufficient light for the small image display element, thereby achieving high-brightness image display. Multiple LCOSs are juxtaposed, each displaying a separate image, and these images are optically synthesized to achieve near-high resolution. By passing the images corresponding to the right eye and the left eye through the LCOS corresponding to the two polarized lights respectively, adjusting the light intensity and performing optical synthesis, three-dimensional display is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a graph of LED light diffusion characteristics; Figure 2 is a graph showing the light diffusion characteristics of an LED controlled by the optical element of the present invention; Figure 3 It is the spectral characteristic diagram of a monochromatic LED; Figure 4 This is a graph showing the luminous efficiency variation of a single-color LED relative to the junction. Figure 5 This is a graph showing the light output variation characteristics of a monochromatic LED relative to input current. Figure 6 This is a structural diagram of a general surface-emitting LED; Figure 7 It is a schematic diagram of the cross-sectional shape of an optical element for controlling the diffusion characteristics of a surface light source LED; Figure 8 2. It is a schematic diagram of the shape of the LF light emission surface of the first embodiment for controlling the diffusion characteristics of the surface light source LED; Figure 9 2. It is a schematic diagram of the shape of the LF light emission surface of the second embodiment for controlling the diffusion characteristics of the surface light source LED; Figure 10 2. It is a schematic diagram of the cross-sectional shape of the LF light emitting surface of the first embodiment of controlling the diffusion characteristics of the surface light source LED; Figure 11 1 is a schematic structural diagram of a first embodiment of an optical component of a projection display device according to the present invention; Figure 12 1 is a schematic structural diagram of a second embodiment of an optical component of a projection display device according to the present invention; Figure 13 1 is a schematic structural diagram of a third embodiment of an optical component of a projection display device of the present invention; Figure 14 is a schematic cross-sectional view of a light source system constituting an optical component of a projection display device of the present invention; Figure 15 It is a schematic cross-sectional view of a reflector which is a part of a light source component of an optical component constituting a projection display device of the present invention; Figure 16 1 is a reflection characteristic diagram of a reflector of a light source component constituting an optical component of a projection display device of the present invention; Figure 17 1 is a reflection characteristic diagram of a reflective film designed on the reflective surface of the PS separation prism shown in the first embodiment of the optical component of the projection display device of the present invention; Figure 18 is a reflection characteristic diagram of a polarization separation filter shown in a second embodiment of an optical component of a projection display device according to the present invention; Figure 19 1 is a reflection characteristic diagram of a reflection film provided on a reflection surface of a prism unit shown in a third embodiment of an optical component of a projection display device of the present invention; Figure 20 is a schematic characteristic diagram of the narrow-angle diffusion characteristics of the LCOS image light obtained from the light source optical component of the embodiment of the present invention; Figure 21 This is a diagram illustrating the law of constant light beam brightness. DETAILED DESCRIPTION

[0019] The following embodiments relate to a projection display device, which includes: an illumination optical assembly equipped with optical elements that control the divergence angle and divergence direction of red, green, and blue monochromatic LED output light as a surface-emitting light source; an image display element that adjusts the light intensity of the received light source light according to an image signal; and a projection lens that magnifies the display screen of the image display element.

[0020] The following embodiments mainly illustrate the illumination optical components when using an LCOS panel as an image display element. However, it goes without saying that the light source optical component can also be efficiently used as a light source for an LCD panel or a DLP panel. In addition, when using LCOS as an image display element, by separating the light source light into S-polarized light and P-polarized light and equipping it with a corresponding LCOS panel, the following new functions can be achieved, providing new added value for the projection display device: ① Using polarized glasses to achieve stereoscopic image viewing. ② The image is divided and displayed on multiple LCOS panels and synthesized through an optical component to achieve an approximately high-resolution display. This optical component enables the realization of a projection display device with new added value.

[0021] The characteristics of the light source optical assembly, the illumination optical assembly and the optical components equipped therewith, used to implement the projection display device in the embodiment of the present invention will be described below.

[0022] Light source optical system: The light source of the present invention uses red, green and blue monochromatic LEDs as surface emitting light sources. The diffusion characteristics of these light sources are as follows: Figure 1 As shown, the LED exhibits a completely diffuse distribution. Therefore, to efficiently capture and utilize all the light from the wide-divergence light source, a plano-convex lens with a large-aperture light-receiving surface must be placed near the LED's emitting surface. Furthermore, in lighting system design, due to the constant brightness law between the emitting surface area and the divergence angle, traditional light source optical components cannot effectively utilize the LED's divergent beam. However, the following technical solutions have been employed to address this issue.

[0023] The divergence angle of the light source of the present invention has Figure 2 The narrow-angle divergence characteristics shown in the figure can increase the light energy density by controlling the divergence angle of the light beam to a narrow angle, compared with the complete diffusion characteristics of the conventional surface-emitting LED shown in the figure, thereby improving the light utilization efficiency of the subsequent lighting optical components. Figure 7 Optical elements 2 and 3 are used to narrow the angle of the diverging light beam and control its directionality. By narrowing the angle and controlling the directionality of the diverging light, the light from the surface-emitting LED can be controlled to resemble a laser (laser, amplification of light by stimulated emission of radiation) beam.

[0024] As an embodiment of the present invention, Figure 6 As shown, the surface-emitting LED is divided into six parts, and a light source optical assembly is formed for the divided light-emitting surface. By dividing according to the aspect ratio of the image display element, the light utilization efficiency of the subsequent lighting optical assembly can be improved. Figure 6The schematic diagram of the surface light source LED used in this embodiment is shown. The light-emitting surface of a compact, high-brightness surface-emitting LED is typically a square with equal horizontal dimension W1 and depth dimension D1. However, image display elements (LCOS) often have a widescreen aspect ratio of 16:9. Therefore, in the embodiments of the present invention, the light-emitting surface is divided into three sections in the depth direction and two sections in the horizontal direction. This segmented structure is described below.

[0025] Based on this light source, Figure 7 In the longitudinal cross-sectional shape of the light source optical assembly shown, the light emitting surface of the surface-emitting LED 1 is divided into 6 parts by the action of the optical element 2, thereby miniaturizing the light emitting surface of the surface-emitting LED 1 ( Figure 7 (The figure shows an embodiment divided into three sections in cross-section.) The light incident surface of optical element 2 is located close to the surface-emitting LED, while the light exit surface faces the light guide 3 (light funnel). The light exit surface is designed to be large, and the side surfaces connecting the two surfaces cause total reflection of the diverging light, thereby approximately reducing the divergence angle. As a result, the light-emitting surface area of ​​this surface light source is reduced, and the divergence angle is also reduced, similar to a surface light source composed of multiple point light sources (such as laser sources).

[0026] Secondly, the incident surface of the optical element 2 is arranged close to the surface-emitting LED 1, which can improve the capture rate of divergent light. Therefore, it is designed to be flat and arranged at small intervals. Since 60% of the input power of the monochromatic LED will be converted into heat and cause high temperature, the optical element 2 is made of heat-resistant glass with a refractive index greater than 1.5. Even if the light incident surface is flat, due to the existence of the air interface, the light from the light source can still be focused by refraction, so the divergence angle can also be reduced on the incident surface. In addition, the light beam of the light source is totally reflected at the side to reduce the divergence angle. Since the critical angle of the light beam increases with the increase of the refractive index, the higher the refractive index of the optical element 2, the more conducive it is to reducing the divergence angle.

[0027] The light exit surface of optical element 2 is divided, creating a secondary light source with a small area and narrow divergence angle. This light is further subdivided at the incident surface of light guide (LF) 3. The light is then projected onto the image display surface of the LCOS panel through the lens shape of the exit surface, passing through the illumination optical assembly, and then superimposed. This enables a high-brightness and uniform brightness display device.

[0028] On the incident surface of the light guide 3, a micro concave-convex surface with a small refractive surface inclination angle is formed to mix the light in the light path before the light exits the exit surface. Figure 9 As shown, on the output surface of LF3, multiple lenses with shapes corresponding to the aspect ratio of the LCOS panel are arranged ( Figure 9 The cross-sectional shapes of these lenses are shown as follows. Figure 10 . The lens surfaces are arranged in a convex shape, the connecting parts of adjacent lenses are gently inclined, and slightly flat parts are provided to improve the molding efficiency of LF. In order not to reduce the light utilization efficiency, these flat parts should be controlled to be less than 1 / 10 of the lens spacing LH, so as to achieve a light source with uniform brightness. The shape of the LF's exit surface is a convex surface facing the lighting optical component. By eccentrically configuring each lens surface, the magnified images of each lens overlap on the LCOS panel after passing through the subsequent lighting system, thereby obtaining a uniform light source beam.

[0029] As another embodiment, a fine lens shape is designed for the output surface of LF3, forming a small concave-convex surface with a small refractive surface inclination angle similar to the incident surface. The connecting surface between adjacent convex surfaces adopts a concave surface with a large curvature radius to obtain a uniform light source beam on the LCOS panel, such as Figure 8 Furthermore, if the LF3 has sufficient length and the exit surface has an area comparable to that of the LCOS panel, a uniform beam can be delivered from the exit surface to the illumination optics and directed toward the LCOS panel.

[0030] Means to improve the color purity of monochrome LEDs: The characteristics of general monochrome LEDs are as follows: Figure 3 As shown. The central wavelength of the blue LED is 455nm, and the wavelength range of 10% brightness is 50nm. The central wavelength of the green LED is 520nm, and the wavelength range of 10% brightness is 70nm. The central wavelength of the red LED is 625nm, and the wavelength range of 10% brightness is 25nm. Figure 11 、 Figure 12 and Figure 13 The reflective properties of the reflector in the light source optical assembly of an image display device are designed to prevent unwanted wavelengths of light from propagating to the subsequent illumination optical assembly, thereby improving color purity. In particular, for green LEDs, if there is a side band around 420nm, the reflective properties of the reflector need to be considered, as this may affect the reliability of the LCOS panel.

[0031] Issues with Single-Color LED Shape and Driver Circuit Mounting Shape like Figure 6 As shown, the light-emitting area is approximately 1 mm², embedded within the outer frame 1b, with electrodes on the bottom and directly soldered to the driver circuit board. The light source optical assembly requires a light-emitting point height H0 accuracy of approximately ±50 μm. While relatively small, this accuracy is sufficient given the unevenness of semiconductor manufacturing. Furthermore, aluminum substrates are primarily used for the driver circuit board due to their ability to dissipate heat generated by the single-color LEDs. Substrate flatness is crucial, and to avoid significant deformation at both ends after reflow, the LED components should be mounted symmetrically across the board, both vertically and horizontally.

[0032] Temperature Characteristics of Monochrome LED Luminous Efficiency The luminous efficiency temperature characteristics of the single-color LED used in this embodiment are as follows: Figure 4 As shown in the figure, the relative light output values ​​of blue and green LEDs do not change significantly when the junction temperature changes. However, the light output efficiency of red LEDs decreases by 40% when the base temperature (25°C) rises by 50°C. Therefore, in order to improve the heat dissipation efficiency of red LEDs, it is necessary to increase the distribution of heat dissipation die casting to make the temperature gradient of input current almost equal. Figure 5 The figure shows how the light output of three single-color LEDs (red, blue, and green) varies with input current. While the light output of green and red LEDs has similar characteristics in response to input current, the blue LED has a higher luminous efficiency. Therefore, the color temperature of white, the composite of the three colors, shifts toward higher temperatures due to the reduced light output efficiency of the red LED. Therefore, the color temperature of white can be maintained within the desired range by monitoring the junction temperature of the red LED and adjusting the input current of the blue and green LEDs.

[0033] Color Synthesis in Light Source Optics In an embodiment of the present invention, the optical assembly of a projection-type image display device comprises a light source optical assembly, an illumination optical assembly, and a projection lens. The light source optical assembly provides the required divergence angle and directional characteristics, while simultaneously achieving the desired color through the characteristics of the reflective film provided on the optical path return mirror, including the aforementioned red, green, and blue LED light beams. In an embodiment of the present invention, Figure 11 、 Figure 12 、 Figure 13 The three embodiments shown have different illumination optical components but the same light source optical components. Figure 14 This is a schematic cross-sectional diagram of the structure of the light source optical component. The reasons for placing the red LED at the position farthest from the illumination optical component are: ① As mentioned above, the luminous efficiency of the red LED will drop significantly as the junction temperature increases. Therefore, the red LED is placed at the end of the LED driver substrate away from the illumination optical component to increase its heat dissipation efficiency, and a larger heat sink is configured compared to the other two colors of LEDs. ② The refractive index of the optical element is smaller for long-wavelength light, so in order to obtain a uniform illumination beam on the LCOS panel through the subsequent illumination optical component, it is best to place the LED at the position farthest from the LCOS panel. ③ In the construction of the light source optical component, the reflective characteristic design of the light path return mirror is easier to achieve, which is a structural advantage.

[0034] Figure 14 and Figure 15The optical path returning mirrors 15, 14, and 13 shown split the divergent light from each monochromatic LED into secondary light sources with angular divergence characteristics, and further clamp the divergence angles together in LF3. At the same time, the split light beams are amplified through their exit surfaces, and through the action of the lens set on the exit surface, a uniform illumination beam is projected onto the LCOS panel.

[0035] The emission spectrum of red LED is as follows Figure 3 As shown in Figure 1, it has a narrow bandwidth, so a red image with high color purity can be obtained. Therefore, the reflection characteristics of the optical path return mirror for light incident at 45 degrees are as follows: Figure 16 As shown, the broadband high reflectivity characteristic allows for a reduced thickness of the reflective film layer, making design easier and reducing costs. On the other hand, the green and blue reflectors need to have narrow bandpass filter properties to match the emission spectrum of each LED. In particular, for green LEDs, in addition to the main green wavelength, the sidebands must also be considered. Light passing through the sidebands improves the color purity of the green image and blocks the blue component, thereby enhancing the reliability of the LCOS panel. For the optical path return mirror corresponding to the blue LED, long-wavelength light above 490nm needs to be transmitted to improve the color purity of the blue image.

[0036] The light path return mirror of the red LED is equipped with a reflector on one side of the LED. Figure 15 As shown, on the light path deflecting mirrors 15 and 14 for the green and blue LEDs, reflective films 15a and 14a with the aforementioned reflective properties are applied on the surfaces opposite the surfaces facing the LEDs. The light is refracted by the substrate of the light path deflecting mirrors before entering the reflective surfaces. This minimizes variations in the reflection position and the angle at which the incident light beam reaches the reflective films, making it easier to achieve an optimized design.

[0037] Embodiment 1 of the first illumination optical component of the optical component of the projection display device: The first embodiment of the optical assembly of the projection type image display device of the present invention is to generate a light beam with a narrow divergence angle and uniform beam density through the light source optical assembly. Figure 17PS separation is performed by the PS separation prism 16, which has the reflective characteristics shown (reflectivity for incident light at 45 degrees). The S-polarized light is reflected by the PS separation film and enters the LCOS panel 12. There, it undergoes polarization conversion based on the image signal and transmits through the PS separation prism 16 as P-polarized image light, producing a first magnified projected image through the projection lens 10. Similarly, the light beam generated by the light source optical assembly passes through the PS separation film through the PS separation prism 16 and enters the LCOS panel 11. There, it undergoes polarization conversion based on the image signal and is converted into S-polarized image light. It then reflects from the PS separation prism 16 and produces a second magnified projected image through the projection lens 10. The first P-polarized image and the second S-polarized image are superimposed on the screen, and then polarized glasses are used to separate the images for the right and left eyes, thereby realizing a projection-type image display device capable of viewing stereoscopic images.

[0038] The polarization performance of the PS separation prism is represented by the ratio Rs / Tp of the reflectivity Rs of S-polarized light and the transmittance Tp of P-polarized light. The larger this value, the higher the image contrast performance produced by the LCOS panel. The higher the refractive index of the PS separation prism, the smaller the divergence angle of the light beam incident on the separation membrane, thereby improving the PS separation capability. In addition, when the PS separation membrane is arranged on the inclined surface of the prism sheet on the light source optical component side of the PS separation prism, good reflection separation characteristics can be obtained with fewer film layers. In this case, the higher the refractive index of the prism substrate, the smaller the divergence angle of the light beam, thereby achieving good separation characteristics.

[0039] Embodiment of the second illumination optical component of the optical component of the projection display device: A second embodiment of the optical assembly of a projection image display device according to the present invention is described below. Figure 12 A second embodiment of an illumination optical assembly for a projection image display device is shown, which can obtain a projection image with twice the resolution of an LCOS panel. The light source optical assembly generates a light beam with a divergence angle of an included angle and a uniform beam density, having Figure 18The PS separation filter 18, which has the reflective characteristics shown (reflectivity for incident light at 45 degrees), features a reflective polarizer placed on the side of the metal mesh facing the light source optical assembly. Compared to PS separation films made from multilayer films, the polarization degree of a reflective polarizer is less dependent on the angle of incidence, resulting in excellent polarization. The reflective polarizer 18 separates P-polarized light from S-polarized light. The S-polarized light is reflected and incident on the LCOS panel 12. After polarization conversion based on the image signal, it becomes P-polarized image light. This light passes through the reflective polarizer 18, resulting in a first magnified projection image from the projection lens 10. Similarly, the light beam emitted from the light source optical assembly passes through the reflective polarizer 18, through the PS separation film, and incident on the LCOS panel 11. After polarization conversion based on the image signal, it becomes S-polarized image light. This light is reflected by the reflective polarizer 18, resulting in a second magnified projection image from the projection lens 10. By superimposing the first P-polarized image and the second S-polarized image on the screen, the resolution of each LCOS panel can be doubled.

[0040] By inputting an image signal with double the resolution as an original signal to each LCOS panel, a projection image display device with double the resolution can be realized.

[0041] Embodiment 3 of the third illumination optical component of the optical component of the projection display device: A third embodiment of the optical assembly of a projection image display device according to the present invention is described below. Figure 13 This is a third embodiment of an optical component of a projection image display device, and has a structure that can achieve high contrast. The divergence angle generated by the light source optical component is narrow and has Figure 17 The PS separation prism 16, which has the reflective characteristics shown (reflectivity for incident light at 45 degrees), separates P-polarized light and S-polarized light. The S-polarized light is reflected by the PS separation film and then passes through the glass block 17 to be incident on the LCOS panel 12. After being polarized according to the image signal, it is converted into P-polarized light and passes through the glass block 17 again. It then passes through the PS separation filter 18, which is composed of a reflective polarizer, to obtain a first magnified projection image through the projection lens 10.

[0042] Similarly, the light beam from the light source optical component passes through the PS separation film through the PS separation prism 16, and then passes through the PS separation film through the PS separation prism 20, and is incident on the LCOS panel 11. After polarization conversion according to the image signal, it becomes S-polarized light, and then is reflected by the PS separation prism 20, reflected according to the characteristics of the reflective film set on the inclined surface of the mirror block 19, and then reflected by the PS separation filter 18, and the image beam is projected into the projection lens 10 to obtain a second magnified projection image.

[0043] The aforementioned projection display device includes an illumination optical assembly. In this system, the first type of P-polarized image light passes through a PS separation prism twice and is reflected once by a PS separation filter, thereby achieving a high degree of polarization and producing a high-contrast image. Meanwhile, the second type of S-polarized image light is reflected once by the PS separation prism and undergoes polarization conversion based on the image signal on the LCOS panel. After reflection from the LCOS, it becomes P-polarized and then passes through the PS separation prism and the PS separation filter, achieving a high degree of polarization. Therefore, a high-contrast image is achieved. In this process, it is crucial to design the optical path lengths of the S-polarized image light and the P-polarized image light to be equal, ensuring that the magnified images are of the same size. A projection display device equipped with this third optical assembly of the illumination optical assembly not only displays stereoscopic images but also produces projected images with a resolution twice that of the LCOS.

[0044] In the above three embodiments, the light beam obtained by the light source optical component and the illumination optical component undergoes polarization conversion and reflection of the image signal through the LCOS, and the divergence characteristics of the image beam obtained are as follows: Figure 20 As shown in Figure 2, the divergence angle of Characteristic O is almost halved compared to Characteristic A, resulting in approximately four times the absolute brightness. By controlling the divergence angle of image light and steering the directional characteristics toward the entrance pupil of the projection lens, a similar effect can be achieved in the Y-axis direction, thereby realizing a projection-type image display device with high light utilization efficiency.

[0045] Regarding the law of constant light beam brightness that determines the brightness of an optical component: Finally, the beam brightness of the rotationally symmetric plane opening used in the lighting system is marked as Figure 21 As shown, when the refractive index is equal, it is expressed by the following relationship: Din / SINin=Dout / SINout This shows that there is a trade-off between angle and area. In other words, reducing the angular distribution to form a collimated light beam will lead to an expansion of the space, and conversely, focusing will lead to an increase in the angular distribution, but the space will shrink, which is an invariant. Therefore, the image display area S1 of the LCOS panel is determined, and after the luminous area of ​​the surface light source is determined, the only acceptable divergence angle can be determined. Therefore, the present invention realizes a virtual smaller area and a narrower divergence angle by arranging an optical element 2 in the light source optical component, dividing the light source of the surface-emitting LED, and totally reflecting a part of the divergent light through the side of the optical element 2. In addition, in LF3, a narrow divergence angle is also achieved through total side reflection, thereby realizing an optical component that is not subject to the law of constant beam brightness.

[0046] While various embodiments have been described in detail above, the present invention is not limited to these embodiments and includes various variations. For example, the above embodiments provide a detailed description of the entire system to facilitate understanding of the present invention and do not necessarily include all described configurations. Furthermore, configurations of one embodiment may be partially replaced with configurations of another embodiment, or configurations of another embodiment may be added to the configurations of another embodiment. Furthermore, configurations of other embodiments may be added, deleted, or replaced with configurations of each embodiment.

Claims

1. A projection image display device, characterized in that: The optical system consists of a light source optical component with a surface-emitting light source, two LCOS panels, an illumination optical component with a polarization separator, and a projection lens. The optical distance from the LCOS panel on one side to the projection lens is equal to the optical distance from the LCOS panel on the other side to the projection lens. The light source optical assembly is close to the surface-emitting light source, the incident surface is divided into multiple planes, the area of ​​the exit surface is larger than the area of ​​the incident surface and the side surface is an inclined surface of the first optical element, and the incident surface is slightly flat and the area of ​​the exit surface opposite to the incident surface is larger than the area of ​​the incident surface, and the connecting side surface between the incident surface and the exit surface is an inclined surface. The second optical element constitutes part of the light source optical assembly and is respectively arranged on the red, green and blue monochromatic surface-emitting LEDs, each monochromatic surface-emitting LED is arranged at a position close to the first optical element, and the exit light of the second optical element is overlapped on the same optical path through the corresponding optical path return mirror and enters the illumination optical assembly; The light beam emitted from the light source optical component passes through the polarization separation device that constitutes the illumination optical component, where the S-polarized light beam is reflected and the P-polarized light beam is transmitted for separation. On one side of the LCOS panel, the S-polarized light beam is modulated to a light intensity and polarization direction that matches the image signal, and is reflected on the reflective surface of the panel. It is then projected through a polarization separation device to form a first magnified projected image. The LCOS panel on the other side transmits a beam of P-polarized light through a polarization separation device, modulates it to a light intensity and polarization direction that matches the image signal, reflects it into an image beam of S-polarized light, and amplifies it through a projection lens to form a second magnified projection image. Finally, the two are superimposed and displayed on the screen.

2. The projection image display device according to claim 1, wherein: In the illumination optical assembly, the optical distance from the LCOS panel on one side to the projection lens is equal to the optical distance from the LCOS panel on the other side to the projection lens.

3. The projection image display device according to claim 1, wherein: The polarization separation device constituting the illumination optical system adopts a reflective polarizing plate as a PS separation filter, and the polarizing plate aligns the metal grid surface with the light source optical component.

4. The projection image display device according to claim 1, wherein: The polarization separation device constituting the illumination optical system is a PS separation prism, wherein the PS separation reflection film is arranged on the inclined surface of the illumination side prism sheet of the PS separation prism, and the prism base material is made of glass material with a refractive index higher than 1.

52.

5. A projection image display device, characterized in that: The invention relates to an illumination optical assembly comprising a light source optical assembly having a surface-emitting light source, two LCOS panels, a polarization separation device, and a projection lens; wherein the optical distance from the LCOS panel on one side to the projection lens is equal to the optical distance from the LCOS panel on the other side to the projection lens; The light source optical assembly is close to the surface emitting light source, and includes a first optical element whose incident surface is divided into multiple planes, whose exit surface is larger than the incident surface and whose side surface is an inclined surface, and a second optical element whose side surface connecting the incident surface and the exit surface is an inclined surface, which constitutes part of the light source optical assembly and is respectively combined with the red, green and blue surface emitting LEDs; Each monochromatic surface-emitting LED is close to the first optical element, and the output light of the second optical element is overlapped on the same optical path through the corresponding optical path returning mirror and enters the lighting optical component. The light beam of the light source optical component is separated into an S-polarized light beam and a P-polarized light beam by the first polarization separation device constituting the lighting component, wherein the S-polarized light beam passes through the glass block for adjusting the optical path length, and then is modulated by the LCOS panel on one side and passes through the first polarization separation device, and is further expanded by the projection lens to form a first expanded projection image, while the P-polarized light beam is separated by the first polarization separation device, passes through the third polarization separation device, and then is modulated by the LCOS panel on the other side, and is then reflected by the third polarization separation device to be an S-polarized light beam, and then is reflected by the oblique surface of the optical path length adjustment glass block, reflected by the second polarization separation device and expanded by the projection lens to form a second expanded projection image, and these two expanded projection images are superimposed on the screen.

6. The projection type image display device according to claim 5, wherein: The projection-type image display device comprises a light source optical assembly having a surface-emitting light source, two LCOS panels, a polarization separation device, and a projection lens, wherein the optical distance from the LCOS panel on one side to the projection lens is equal to the optical distance from the LCOS panel on the other side to the projection lens; The light source optical assembly has an optical element for converting divergent light emitted by a surface-emitting light source. The light beam emitted from the light source optical assembly is separated by a PS separation device of the lighting assembly, wherein the S-polarized light beam is reflected and the P-polarized light beam is transmitted; On one side of the LCOS panel, the S-polarized light beam is modulated in terms of light intensity and polarization direction according to the image signal, then reflected on the reflective surface of the panel and passed through the PS separation means. The LCOS panel on the other side separates the P-polarized light beam through the PS separation means, modulates the light intensity and polarization direction according to the image signal, then reflects on the reflective surface of the panel and is reflected as an S-polarized light beam through the PS separation means.

7. The projection image display device according to claim 5, wherein: The optical distance from one LCOS panel of the illumination optical assembly to the projection lens is equal to the optical distance from the other LCOS panel to the projection lens.

8. The projection image display device according to claim 5, wherein: The PS separation device of the illumination optical assembly adopts a reflective polarizing plate with the metal mesh surface facing the light source optical assembly as a PS separation filter.

9. The projection type image display device according to claim 5, wherein: The PS separation device of the illumination optical system is a PS separation prism. The PS separation reflective film is arranged on the inclined surface of the prism sheet on one side of the illumination component of the PS separation prism. The prism substrate is made of glass material with a refractive index of 1.52 or more.

10. The projection type image display device according to claim 5, wherein: The projection type image display device is composed of a light source optical system with a surface emitting light source, an illumination optical assembly consisting of two LCOS panels and a polarization separation device, and a projection lens; In the illumination optical assembly, the optical distance from one LCOS panel to the projection lens is equal to the optical distance from another LCOS panel to the projection lens; the light source optical assembly includes an optical element that converts divergent light from a surface-emitting light source into a smaller divergent light beam; The first polarization separation device in the illumination optical assembly separates the light source beam by reflecting an S-polarized beam and transmitting a P-polarized beam. The separated S-polarized beam passes through a glass block for adjusting the optical path length and reaches an LCOS panel. On the LCOS panel, the S-polarized beam is modulated in intensity and polarization direction according to the image signal. The S-polarized beam is then reflected by the reflective surface of the panel, passes through the first polarization separation device, passes through the second polarization separation device, and is magnified by the projection lens to form a first magnified projection image. The first PS separation device separates the P light through the P-polarized beam in the light source beam. The third polarization separation device transmits the P-polarized beam. On another LCOS panel, the P-polarized beam modulates the light intensity and polarization direction according to the image signal, and is reflected on the reflective surface of the panel. After being reflected by the third PS separation device as an S-polarized image beam, it is reflected on the inclined surface of the optical path length adjustment glass block. After being reflected by the second polarization separation device, it is magnified by the projection lens to form a second magnified projection image, which is superimposed and displayed on the screen.

Images