Projection device

Abstract

The application protects a projection system, comprising: a light source module comprising a plurality of light source modules, for emitting a first light beam, a second light beam and a third light beam; a liquid crystal modulation module comprising a plurality of liquid crystal modulation modules, arranged on the light path of the light source module, for modulating the first light beam, the second light beam and the third light beam into a first image light, a second image light and a third image light; a light combination module arranged on the light path of the plurality of liquid crystal modulation modules, for combining the first image light, the second image light and the third image light to generate a color image light; a light beam convergence assembly arranged between the light source module and the light combination module, for converging or partially converging the light beam to achieve non-telecentric illumination; and a projection lens arranged on the light path of the light combination module, for imaging the image light to display an image; wherein the plurality of liquid crystal modulation modules and the light combination module adopt short-side light combination to reduce the back aperture of the lens, thereby reducing the volume of the projection system.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a projection device. Background Technology

[0002] With the advancement of information technology, people's demands for visual enjoyment are increasing. "Visual impact" has become a standard for judging display performance. Visual impact comes not only from clear images but also from ultra-large screen sizes. To meet this demand, large-screen displays have emerged. Taking the living room as an example, recent market sales show that LCD TV sizes are gradually increasing. However, the advent of the information age has led to fragmented time, and the living room is no longer the only place for video entertainment. Moreover, due to the large size and weight of LCD TVs, they cannot be used anytime, anywhere. On the other hand, although mobile phone screens have made significant progress in size, and even larger smart tablets designed specifically for entertainment have appeared, their display methods limit the achievement of truly large-screen displays. Therefore, to achieve flexible large-screen displays, the only current technological route is projection.

[0003] A projection display system mainly consists of an illumination system, an optomechanical system, and a projection lens. The spatial light modulator, also known as a "light valve," is a crucial component in the optomechanical system. A light valve is typically a pixelated planar device, where each pixel can independently control the incident illumination light through transmission or reflection, thereby controlling the luminous flux of each pixel to form the displayed image. Based on the type of spatial light modulator, projection display systems can be broadly classified into reflective DMD (Digital Micro-Mirror Device) projection, transmissive LCD (Liquid Crystal Display) projection, and reflective LCoS (Liquid Crystal on Silicon) projection. Based on the number of spatial light modulators, they can be further classified into single-panel projection, dual-panel projection, and triple-panel projection.

[0004] As is well known, the core principle of display is based on the red, green, and blue three-primary-color display principle. This means that red, green, and blue image information are displayed separately through light valves, and then the three monochrome images are combined through time integration (usually in single-panel projection) or spatial integration (usually in three-panel projection) to allow the human eye to perceive a single color image. However, the time integration method is easily limited by the "rainbow effect," therefore, this method is not the optimal solution for large-screen displays.

[0005] Three-panel projection can fundamentally solve the rainbow effect problem. However, the three-panel projection solution has problems such as complex optical path system, high hardware cost, and large system size. Therefore, how to fundamentally solve the disadvantages of three-panel projection such as complex optical path, high cost and large size is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] To address the aforementioned deficiencies of the prior art, this application provides a projection device with a simple optical path, low cost, and small size, comprising a light source module including multiple light source modules for emitting a first beam, a second beam, and a third beam; a liquid crystal modulation module including multiple liquid crystal modulation modules disposed in the output light path of the light source module, the multiple liquid crystal modulation modules being used to modulate the first beam, the second beam, and the third beam emitted by the multiple light source modules into a first image light, a second image light, and a third image light, respectively; a beam combining module disposed in the output light path of the multiple liquid crystal modulation modules, for combining the first image light, the second image light, and the third image light to generate colored image light; a beam converging component disposed between the light source module and the beam combining module, for converging or partially converging the beams to achieve non-telecentric illumination; and a projection lens disposed in the output light path of the beam combining module, for imaging the image light onto a preset projection plane or screen to display an image; wherein, the multiple liquid crystal modulation modules and the beam combining module employ short-side beam combining to reduce the back focal length of the lens.

[0007] In some embodiments, the light source module includes a first light source module, a second light source module, and a third light source module; the liquid crystal modulation module includes a first liquid crystal modulation module, a second liquid crystal modulation module, and a third liquid crystal modulation module, wherein the second liquid crystal modulation module is disposed along a first direction in the output light path of the second light source module, the first liquid crystal modulation module is disposed along a second direction perpendicular to the first direction in the output light path of the first light source module, and the third liquid crystal modulation module is disposed along the opposite direction of the second direction in the output light path of the third light source module; the light combining module is disposed along the first direction in the output light path of the second liquid crystal modulation module of the liquid crystal modulation module.

[0008] In some embodiments, the liquid crystal modulation module includes a polarizer, a modulation panel, and an analyzer. The polarizer is used to polarize the light beam emitted by the light source module so that the polarization state of the light beam is parallel to the liquid crystal direction of the modulation panel. The analyzer is used to analyze the polarization of the light beam modulated by the modulation panel so that it can be recognized by the human eye.

[0009] In some embodiments, the modulation panel is an LTP-LCD.

[0010] In some embodiments, the first liquid crystal modulation module, the second liquid crystal modulation module, and the third liquid crystal modulation module respectively include a first modulation panel, a second modulation panel, and a third modulation panel. The long side direction of the second modulation panel is perpendicular to the first direction, parallel to the long side direction of the first modulation panel and the third modulation panel, and perpendicular to the short side direction of the light combining module.

[0011] In some embodiments, the first light source module, the second light source module, and the third light source module of the light source module each include a light-emitting unit, a light-collecting unit, and a collimating lens. The light-emitting unit is used to emit a light beam, the light-collecting unit is used to collect the light beam emitted by the light-emitting unit, and the collimating lens is used to collimate the light beam emitted by the light-collecting unit.

[0012] In some embodiments, the light source module further includes a supplementary second light source module, which is arranged along a second direction and includes a supplementary second light-emitting unit along the second direction; wherein, the first light source module is arranged along the second direction, the second light source module is arranged along a first direction, and the third light source module is arranged along a direction opposite to the second direction, and the supplementary light emitted from the supplementary second light source module is combined with the second light beam emitted from the second light source module and then irradiates the second liquid crystal modulation module.

[0013] In some embodiments, a supplementary light-combining unit is provided on the common emission path of the second light-emitting unit and the supplementary second light-emitting unit of the second light source module. The supplementary light-combining unit is used to reflect the supplementary light beam emitted by the supplementary second light-emitting unit to the second light-emitting unit and transmit the second light beam emitted by the second light-emitting unit.

[0014] In some embodiments, the reflective surface of the second light-emitting unit is coated with phosphor that is excited to emit the second light beam, and the supplementary light beam is a blue laser.

[0015] In some embodiments, the first light source module is arranged along a first direction, the second light source module is arranged along a first direction, and the third light source module is also arranged along a first direction. The first light beam emitted from the first light source module is deflected by the first deflection component and then incident on the first liquid crystal modulation module along a second direction. The light beam emitted from the third light source module is deflected by the third deflection component and then incident on the third liquid crystal modulation module in the opposite direction to the second direction.

[0016] In some embodiments, the first deflection assembly includes a first light recovery assembly, a first light transmission device, and a first deflection element, for adjusting the transmission direction of the first light beam from a first direction to a second direction; the third deflection assembly includes a third light recovery assembly, a third light transmission device, and a third deflection element, for adjusting the transmission direction of the third light beam from the first direction to the opposite direction of the second direction.

[0017] In some embodiments, the first folding element and the third folding element are hollow structures or solid right-angle prisms.

[0018] In some embodiments, the light collecting unit is a cone reflector used to collect the light beam emitted by the light emitting unit in a non-imaging manner.

[0019] In some embodiments, the light collecting unit is a second lens, used to collect the light emitted from the second light-emitting component and emit a collimated first beam under the collimation of the collimating lens.

[0020] In some embodiments, the second lens is a collecting lens; the polarizer is used to achieve spot shaping and light recovery, including a circular spot distribution, a first region, and a second region, wherein the circular spot distribution is the spot shape when the light beam is transmitted to the modulation panel, the first region is a rectangular region adapted to the shape of the modulation panel and inscribed within the circular spot distribution, and the first region is configured as a light circulation film layer for polarizing the spot in the rectangular region; and the second region is disposed on the edge portion of the circular spot distribution other than the first region, and the second region is configured as a specular reflection film layer for recovering the edge spot.

[0021] In some embodiments, the second lens is a freeform lens, used to make the beam surface distribution a circular rectangle larger than the illumination area of ​​the modulation panel; the collimating lens is a Fresnel lens; the polarizer is used to achieve beam spot shaping and light recovery, including a circular rectangular beam spot distribution, a first region and a second region, wherein the circular rectangular beam spot distribution is the beam spot shape when the beam is transmitted to the modulation panel; the first region is a rectangular region adapted to the shape of the modulation panel and inscribed within the circular rectangular beam spot distribution; and the first region is configured as a light circulation film layer for polarizing the beam spot in the rectangular region; and the second region is disposed on the edge portion of the circular rectangular beam spot distribution other than the first region; the second region is configured as a specular reflection film layer for recovering the edge beam spot.

[0022] In some embodiments, the projection lens is a non-telecentric ultra-short-throw lens, including a reflector and a reflector cup, used to deflect the illumination light emitted from the light combining module.

[0023] Compared with existing technologies, the light combining scheme using short-side light combining can make full use of the light combining structure of the light combining module itself, and greatly reduce the back cutoff distance from the liquid crystal modulation module to the projection lens, thus reducing the volume of the entire projection device. Because a beam converging component is added in front of the light combining module, the illumination light is shaped into a non-telecentric beam that contracts and converges or partially converges along the principal optical axis when it enters the light combining module. This greatly reduces the effective illumination area when the illumination light reaches the lens, thereby reducing the lens diameter and significantly reducing the volume of the entire illumination system. Attached Figure Description

[0024] Figure 1 A schematic diagram of the basic optical architecture of a projection device;

[0025] Figure 2 This is a schematic diagram of the structure of a first embodiment of the projection device of this application;

[0026] Figure 3 This is a schematic diagram of the long-side light combining structure and the short-side light combining structure of this application;

[0027] Figure 4 This is a schematic diagram of the projection device 110 according to Embodiment 2 of this application;

[0028] Figure 5 This is a schematic diagram of the projection device 120 according to Embodiment 3 of this application;

[0029] Figure 6 This is a schematic diagram of the projection device 130 according to Embodiment 4 of this application;

[0030] Figure 7 This is a schematic diagram of the projection device 140 according to Embodiment 5 of this application;

[0031] Figure 8 This is a schematic diagram of the structure of the polarizer 241g in Embodiment 5 of this application;

[0032] Figure 9 This is a schematic diagram of the projection device 150 according to Embodiment Six of this application;

[0033] Figure 10 This is a schematic diagram of the structure of the polarizer 251g in Embodiment Six of this application;

[0034] Figure 11 This is a schematic diagram of the projection device 160 according to Embodiment 7 of this application;

[0035] Figure 12 This is a schematic diagram of the projection device 170 according to Embodiment 8 of this application; Detailed Implementation

[0036] In the display field, DMD and LCOS have complex manufacturing processes and high costs. Since both are reflective devices, their application in three-panel projection would make the optical path more complex and make it difficult to further reduce the size. Therefore, the projection architecture of three-panel LCD has always been a commonly used projection solution in three-panel systems. However, the traditional projection architecture of three-panel LCD still has the problems of high cost and large size.

[0037] Currently, LCD panels are classified into two types based on two processes: Low Temperature Poly-Silicon (LTPS) and High Temperature Poly-Silicon (HTPS). HTPS technology offers higher precision, and the core HTPS technology is largely controlled by foreign companies. The pixel size of the liquid crystal can reach below 10µm, achieving a high aperture ratio and resolution, which can meet the size requirements of projectors for light valves. However, HTPS has extremely high requirements for the manufacturing process, resulting in higher costs. At the same time, this panel requires a sufficiently small light source extension, generally using lamps or lasers as the light source, leading to a larger optical engine size.

[0038] LTP-LCD panels, also known as color modulation panels, are manufactured using LTPS. Due to their simple manufacturing process and low cost, they have high production capacity in China. However, precisely because of this simple process, their precision is lower, with pixel sizes typically exceeding 25µm. This results in larger panels; for a given resolution, the entire LTP-LCD panel is large, leading to a larger lens and ultimately a larger overall projection device. Therefore, LTP-LCDs are generally used in single-panel projectors and have never been used in three-panel projectors.

[0039] Therefore, this application proposes a novel projection architecture that employs a non-imaging method to illuminate three LTP-LCD panels and a short-side light-combining scheme. This reduces the requirement for a relatively small optical expansion of the incident light source, technically solving the technical defects of three-panel projection architectures caused by the large size of LTP-LCD panels. It overcomes the technical prejudice that large LTP-LCD panels are not used in three-panel projection architectures, and addresses the problems of high cost, difficulty in mass production, and large size inherent in traditional three-panel HLTP-LCD architectures, making them unsuitable for commercial, educational, and home projection applications. It also truly applies mass-producible large-panel LTP-LCDs to three-panel projection architectures, accelerating the rapid industrialization of low-to-mid-range projection products in the projection display industry. Understandably, the projection device of this application, in addition to being used in traditional business and educational projectors, is also better suited for miniature projectors and mobile phone integrated projectors due to its simple architecture and powerful functionality, possessing a very broad application prospect.

[0040] Please see Figure 1 The diagram below shows the basic optical architecture of the projection device of this application. The projection device includes a light source module 10, a liquid crystal modulation module 20, a light combining module 30, and a projection lens 40. The light source module 10 includes multiple light source modules, each capable of emitting a first beam, a second beam, and a third beam, which are red, green, or blue light, respectively. The liquid crystal modulation module 20 includes multiple liquid crystal modulation modules and is disposed in the output light path of the light source module 10. It is used to modulate the first beam, the second beam, and the third beam into a first image light, a second image light, and a third image light, respectively. The first beam, the second beam, and the third beam are emitted from the light source module 10 and then incident on the multiple liquid crystal modulation modules of the liquid crystal modulation module 20 in a non-imaging manner, which greatly reduces the number of components and the distance between the light source module 10 and the display module 20, and can effectively reduce the size of the lighting system. The light combining module is disposed in the output light path of the multiple liquid crystal modulation modules and is used to combine the first image light, the second image light, and the third image light modulated by the multiple liquid crystal modulation modules to produce colored image light. The projection lens 40 is disposed in the output light path of the light combining module and is used to image the image light onto a preset projection plane or screen to display an image. Taking the direction of image light incident on the projection lens as the first direction as an example, the multiple liquid crystal modulation modules of the liquid crystal modulation module 20 and the light combining module combine light in a short-side light combining manner (the meaning of short-side light combining will be explained in detail later). This method can reduce the volume of the light combining module 30 in the first direction and also effectively reduce the back cutoff of the projection lens 40, thereby greatly reducing the volume of the entire projection device.

[0041] The embodiments of this application will now be described in detail with reference to the accompanying drawings and implementation details.

[0042] Please see Figure 2This is a schematic diagram of the structure of an embodiment of the projection device of this application. The projection device 100 includes a light source module 10, a liquid crystal modulation module 20, a light combining module 30, and a projection lens 40. The light source module 10 includes a first light source module 10r, a second light source module 10g, and a third light source module 10b, which are respectively used to emit a first light beam, a second light beam, and a third light beam. In some embodiments, the first light beam is red light, the second light beam is green light, and the third light beam is blue light. The light source module 10 can be a laser or an LED, or it can use a laser fluorescence scheme. This application does not limit the specific type of the light source module 10. The liquid crystal modulation module 20 includes a first liquid crystal modulation module 20r, a second liquid crystal modulation module 20g, and a third liquid crystal modulation module 20b, which are respectively used to provide non-imaging illumination to the liquid crystal modulation module 20. The first beam, the second beam, and the third beam are modulated. In some embodiments, the first liquid crystal modulation module 20r, the second liquid crystal modulation module 20g, and the third liquid crystal modulation module 20b are all LTP-LCD modules, which can provide a larger modulation area and reduce the requirement for the expansion of the beam incident on the liquid crystal modulation module 20. The first beam, the second beam, and the third beam after being modulated by the first liquid crystal modulation module 20r, the second liquid crystal modulation module 20g, and the third liquid crystal modulation module 20b are respectively represented as the first image light, the second image light, and the third image light. The first image light, the second image light, and the third image light are respectively incident on the light combining module 30 and combined into a color image light, and then imaged onto a preset projection plane by the projection lens 40.

[0043] The first light source module 10r, the second light source module 10g, and the third light source module 10b are used to emit a first beam, a second beam, and a third beam, respectively. The first light source module 10r is incident on the light combining module 30 along a second direction perpendicular to the first direction; the second light source module 10g is incident on the light combining module 30 along the first direction; and the third light source module 10b is incident on the light combining module 30 along a direction opposite to the second direction. In this embodiment, since the components of the first light source module 10r, the second light source module 10g, and the third light source module 10b are identical, differing only in their relative positions to the light combining module 30, the second light source module 10g is used as an example. The second light source module 10g includes a second light-emitting unit 101g, a light-collecting unit, and a collimating lens 103g arranged sequentially along the first direction. In this embodiment, the second light-emitting unit 101g is a green laser used to emit green light.

[0044] In this embodiment, the light collecting unit is a conical reflector 102g. The smaller end of the conical reflector 102g is the incident surface, and the larger end is the exit surface. This allows the green light emitted by the second light-emitting unit 101g to enter the conical reflector through the incident surface, be reflected by the sidewalls of the conical reflector, and then exit through the exit surface or directly. This results in the exit spot area being larger than the incident spot area, thereby reducing the beam divergence angle and illuminating the second liquid crystal modulation module in a non-imaging manner. In this embodiment, the conical reflector 102g is a solid conical light guide rod, where the beam is reflected by total internal reflection from the side of the conical reflector 102g. In other embodiments of this application, the conical reflector 102g can also be a hollow conical reflector composed of a reflective plate / reflective surface, which will not be elaborated here.

[0045] In this embodiment, the emitted light from the conical reflector 102g illuminates the collimating lens 103g, thereby collimating the second beam and allowing it to smoothly enter the downstream optical element in the optical path. It is understood that in other embodiments of this application, a collimating lens may not be provided, for example, when the second beam from the upstream optical path satisfies a small divergence angle.

[0046] In some embodiments, a light recovery component (not shown) may be provided between or after the aforementioned conical reflector 102g and collimating lens 103g. In this case, taking the area between the conical reflector 102g and collimating lens 103g as an example, if the light emitted by the second light-emitting unit 102g is unpolarized green light, then part of the light will continue to be emitted in a single polarization state after passing through the light recovery component, and part of the light will be reflected back into the conical reflector 102g after being reflected back and forth within the conical reflector 102g, and then emitted again through the emission surface of the conical reflector 102g to reach the light recovery component. That is, the light recovery component is used to selectively transmit a single polarization state of the light emitted by the second light-emitting unit, and recover the light of another polarization state, thereby improving the utilization rate of the first beam. It is understood that if the second light-emitting unit 102g uses an LED or laser phosphor, the above structure can re-disperse the polarized light returning from the light recovery component into natural light, which can then continue to participate in the light cycle. In some embodiments, in order to reduce the number of times the recovered first beam is recovered, a structure such as a quarter-wave plate (not shown) can be provided in the conical reflector to change the polarization state of the beam. In this application, the light recovery component can be, for example, a wire grid polarizer. Similarly, the first light source module 10r includes a first light-emitting unit 101r, a conical reflector 102r, and a collimating lens 103a arranged sequentially along the second direction, wherein the first light-emitting unit 101a is a red laser; the third light source module 10b includes a third light-emitting unit 101a, a conical reflector 102b, and a collimating lens 103b arranged sequentially in opposite directions along the second direction, wherein the third light-emitting unit 101b is a red laser. The specific principle is similar to that of the second light source device 10g, and will not be described again here.

[0047] See also Figure 2Taking the second light source module 10g as an example, the first light beam from the second light source module 10g is incident on the second liquid crystal modulation module 20g. The second liquid crystal modulation module 20g includes a polarizer 201g and a second modulation panel 202g. The polarizer 201g is used to control the polarization state of the second light beam so that the polarization state of the second light beam is parallel to the liquid crystal direction of the second modulation panel 202g, thereby enabling the second modulation panel 202g to modulate the second light beam and generate second illumination light. In this embodiment, the second modulation panel 202g includes an analyzer (not shown) disposed on its rear surface. The analyzer is used to analyze the polarization of the second illumination light modulated by the second modulation panel 202g, so that it can be recognized by the human eye. It can be understood that in some embodiments, the analyzer can also be disposed separately from the second modulation panel 202g to avoid direct thermal contact between the two, thereby avoiding the heat generated by the second modulation panel 202g from causing aging and damage to the analyzer. The second illumination light generated by the second modulation panel 202g illuminates the light combining module 30 along the first direction. Similarly, the first illumination light generated by the first modulation panel 202a illuminates the light combining module 30 along the second direction, and the third illumination light generated by the third modulation panel 202b illuminates the light combining module 30 in the opposite direction to the second direction. The relative positions of the first modulation panel 202a, the second modulation panel 202g, the third modulation panel 202b, and the light combining module 30 will be described below.

[0048] Please see also Figure 3 This is a schematic diagram of the long-side light combining and the short-side light combining structure of this application. It can be understood that, to achieve better display effects, the standard aspect ratio of LTP-LCD panels is generally 16:9, 16:10, or 4:3. Therefore, LTP-LCD panels are not square, but have long and short sides. Furthermore, in a three-panel projection, apart from the different color modulations, the specifications of the three panels should be identical. For example... Figure 3 In the long-side light combining method shown in (r), the long side direction of the green light panel is parallel to the first direction and perpendicular to the long side directions of the red light panel and the blue light panel, respectively. In this case, the distance from the green light panel to the projection lens 40, that is, the back clip of the projection lens 40, is at least equal to the length of the long sides of the red light panel and the blue light panel. And as... Figure 3 In the short-side light combining scheme shown in (g), the long side direction of the second modulation panel 202g is perpendicular to the first direction and parallel to the long side direction of the first modulation panel 202a and the third modulation panel 202b, such that the back cutoff distance from the first modulation panel 202a to the projection lens 40 is at least equal to the short side length of the first modulation panel 202a and the third modulation panel 202b. Since the short side of the LTP-LCD panel is always smaller than the long side, the short-side light combining scheme of this application can effectively reduce the back cutoff distance of the traditional long-side light combining scheme, thereby reducing the volume of the projection device.

[0049] Please continue reading Figure 3 The light combining module 30 is used to combine the first illumination light, the second illumination light, and the third illumination light. It can be understood that when the above-mentioned short-side light combining scheme is adopted, the light combining module 30 can adopt an X-cube light combining prism. The light combining prism includes a first coating surface (not shown) and a second coating surface perpendicular to it. The first coating surface and the second coating surface are divided into a first coating segment 311, a second coating segment 312, a third coating segment 313, and a fourth coating segment 314 in a clockwise direction. The first coating segment 311 is a green-transparent and red-reflecting film, the second coating segment 312 is a red-green-transparent and blue-reflecting film, the third coating segment 313 is a blue-green-reflecting and red-reflecting film, and the fourth coating segment 314 is a green-transparent and blue-reflecting film.

[0050] Simultaneously, the long side of the light-combining prism is parallel to the long side of the second modulation panel 202g, and the length of the long side of the light-combining prism is greater than or equal to the length of the long side of the second modulation panel 202g. The short side of the light-combining prism is parallel to the short side of the second modulation panel 202g, and the length of the short side of the light-combining prism is greater than or equal to the length of the short side of the second modulation panel 202g. When projected along a direction perpendicular to both the first and second directions, the light-combining module 30 forms an "X" shape, where the "X" shape represents the projection lines of the first and second coating surfaces. With this configuration, the first and third illumination lights can be reflected to the first direction and combined with the second illumination light to produce colored illumination light.

[0051] The projection lens 40 is positioned in the output light path of the light combining module 30 to project a color image to a predetermined position, forming an image that can be viewed by the audience. In this embodiment, the projection lens 40 consists of multiple lenses. It is understood that those skilled in the art can design the product lens according to the requirements of the projection scenario, and the projection lens may also include optical structures such as reflective curved surfaces, which will not be elaborated here.

[0052] In some embodiments, a pixel expansion module 50 may be disposed between the light combining module 30 and the projection lens 40. The pixel expansion module 50 is used to translate the light beam of the color image along a direction perpendicular to the optical axis, so that the color images at different translation positions are superimposed in sequence to improve the display resolution of the final projection. The pixel expansion module 50 may be a transparent flat plate optical device (XPR: Expanded Pixel Resolution) whose rotation angle is controlled by current or voltage. When the transparent plate of the pixel expansion module 50 rotates at a certain angle, the light passing through the transparent plate is translated as a whole after two refractions. The transparent plate stays at the rotation position for a predetermined time and then rotates to other positions. In one image frame cycle, the pixel expansion module 50 may include 2 stable states or 4 stable states. The image is correspondingly split into 2 subframes or 4 subframes. The human eye superimposes the captured 2 or 4 images through time integration to form a high-resolution image in the brain, thereby realizing a high-resolution projection display of 4K or 1080P. It is understood that the pixel offset device can also include more steady states to achieve higher resolution, and this application does not limit the number of pixel multiplications.

[0053] In other embodiments, the pixel shifting device can also be a liquid crystal birefringence device, which controls the deflection angle of liquid crystal molecules by voltage, thereby shifting the light passing through the liquid crystal birefringence (E-shift) device to achieve the effect of overall pixel shifting, which is similar to the mechanically rotating pixel shifting device described above, and will not be described in detail here.

[0054] It is understandable that in the above scheme, since the light source module 10 uses a non-imaging method to illuminate the liquid crystal modulation module 20, the distance between the light source module 10 and the liquid crystal modulation module 20 is small, effectively reducing the size of the illumination system. Simultaneously, due to the use of a short-side light-combining scheme, the light-combining structure of the light-combining module 30 itself can be fully utilized, and the back cutoff distance from the first modulation panel 202a to the projection lens 40 is greatly reduced, thus reducing the overall volume of the projection device. However, since the colored illumination light emitted from the light-combining module 30 is still telecentric illumination light illuminating the lens, and since lenses typically have an offset of over 100%, the lens diameter d needs to meet certain requirements for telecentric illumination systems. Where L is the length of the effective illumination area of ​​the panel and W is the width of the effective illumination area of ​​the panel, this means that the lens size is still not small enough and the cost is high, thus limiting the further miniaturization of the entire projection device. To this end, this application also proposes a better solution that further reduces the size.

[0055] For details, please see Figure 4 The schematic diagram shown is of the projection device 110 according to Embodiment 2 of this application. Figure 4 What is shown is actually Figure 2The illustrated embodiment is a modified embodiment of Example 1; therefore, the components and numbers are the same as those in Example 1.

[0056] For the same parts, please refer to the description in Embodiment 1. The difference between this embodiment and Embodiment 1 is that a beam converging component is added to the projection device in this embodiment. The beam converging component can be located at any position between the collimating lens of the light source module and the beam combining module, and is used to converge or partially converge the illumination beam. In this embodiment, the beam converging component is located between the polarizer and the modulation panel of the liquid crystal modulation module. Please continue to refer to... Figure 4 Taking the optical path configuration between the second light source module 11g and the light combining module 30 as an example, the second beam converging component 213g is disposed between the polarizer 211g and the second modulation panel 212g of the second liquid crystal modulation module 21g. This shapes the collimated green parallel light emitted from the second light source module 11g into a beam that converges or partially converges along the main optical axis of the first direction and illuminates the light combining module. In other words, it achieves non-telecentric illumination of the panel and the light combining module. Preferably, the second beam converging component 213g can be attached to the polarizer 211g and the second modulation panel 212g. Similarly, the first light source module 10a and the third light source module 10b are also configured in the same way, that is, the first beam converging component 213r and the third beam converging component 213b are respectively disposed at corresponding positions, thereby achieving non-telecentric illumination of the light combining module 30. This further reduces the distance from the light source module to the light combining module along the first direction, the second direction, and the opposite direction of the second direction, and reduces the volume of the entire lighting system.

[0057] In some embodiments, the beam converging component may be a field lens, a Fresnel lens, or a freeform lens. Of course, it is not limited to these; any optical element that can converge or partially converge the first beam may be used.

[0058] In this embodiment, the addition of a beam converging component in front of the beam combining module causes the illumination light to be shaped into a non-telecentric beam that contracts and converges or partially converges along the principal optical axis when it enters the beam combining module 30. This greatly reduces the effective illumination area when the illumination light reaches the lens, thereby reducing the lens diameter and significantly reducing the volume of the entire illumination system.

[0059] In the second embodiment, the first light source module 11r, the second light source module 11g, and the third light source module 11b emit the first beam, the second beam, and the third beam, respectively. After being converged by the first beam converging component 213r, the first beam converging component 213g, and the third beam converging component 213b, the beams are combined by the light combining module and projected through the lens. However, in this device, when LEDs are used as the light-emitting components, the second light-emitting component 111g has a low conversion efficiency. Therefore, under the same conditions, the second beam emitted by the second light source module is significantly weaker than that of the first and third light source modules. To address this issue, this application further improves the optical path configuration of the second light source module.

[0060] For details, please see Figure 5 The schematic diagram shown is of the projection device 120 according to Embodiment 3 of this application. This embodiment is similar to... Figure 4 The embodiments shown are similar, except that the light source module in this embodiment also includes a supplementary second light source module 12b1. The supplementary second light source module 12b1 is arranged along the second direction, and its structure is basically the same as that of the second light source module 12g (the second light-emitting unit 121g, the light-collecting unit 122g and the collimating lens 123g arranged sequentially along the first direction). It includes a supplementary second light-emitting unit (not shown in the figure), a light-collecting unit (not shown in the figure) and a collimating lens (not shown in the figure). The only difference is that the supplementary second light-emitting unit of the supplementary second light source module emits blue laser light, and the outer surface of the second light-emitting unit 121g is a reflective surface and is coated with a green light-emitting material, such as green phosphor. Furthermore, a supplementary light-combining unit 320g is provided on the common emission path of the second light source module 12g and the supplementary second light source module 12b1. The supplementary light-combining unit 320g is provided with a film layer for reflecting blue laser and transmitting red and green fluorescence. It is used to reflect the blue laser emitted by the supplementary second light source module 12b1 onto the green phosphor of the second light-emitting component 121g, exciting green fluorescence, thereby emitting a high-brightness green light together with the second light-emitting component. That is, by additionally providing the supplementary second light source module 12b1, the green phosphor on the second light-emitting component 121g can be excited from both sides, which helps to improve the excitation efficiency of the laser and thus improve the light efficiency. Optionally, a corresponding supplementary light source module can also be provided at the corresponding position of the third light source module. It is only necessary to set the third light-emitting unit in the third light source module to be a light-emitting unit coated with red phosphor, and the supplementary light-combining unit to be blue-reflecting and red-transmitting. Its principle is the same as the principle of supplementing green light by the second light source module, and will not be described in detail here.

[0061] Optionally, the supplementary light combining unit 320g can also be configured as a regional film (not shown), including a central region and an edge region. The central region is used to reflect the blue laser with a smaller optical spread emitted by the supplementary second light source module onto the second light-emitting component, while the edge region is used to transmit the green light emitted from the second light-emitting component and the green fluorescence generated by the green phosphor on the second light-emitting component excited by the blue laser. In this way, the conversion and utilization efficiency of green light excited from both sides can be further improved.

[0062] Furthermore, to further reduce the size of the optical path structure diagram of Embodiment 2, this application also proposes Embodiment 4, please refer to [link to Embodiment 4]. Figure 6 The schematic diagram shown below illustrates the structure of the projection device 130 in Embodiment 4 of this application. This embodiment is similar to... Figure 4 The embodiments shown are similar, except that: in this embodiment, the first light source module and the third light source module are both arranged along the first direction, but the first liquid crystal modulation module 23r (including polarizer 231r and first modulation panel 232r) and the first beam converging component 233r are still arranged along the second direction, and the third liquid crystal modulation module 23b (including polarizer 231b and third modulation panel 232b) and the third beam converging component 233b are still arranged in the opposite direction to the second direction. Between the first light source module and the first liquid crystal modulation module 23r, a first deflection component is also provided. The first deflection component includes a first light recovery component 631r, a first light transmission device 632r and a first deflection element 633r, which is used to adjust the transmission direction of the first beam from the first direction to the second direction. By such a setting, the length of the device along the second direction can be compressed because the transmission direction of the first beam has been changed.

[0063] Specifically, the first light recovery component 631 is used to transmit light of the first polarization state of the first beam emitted by the first light source module and reflect light of the second polarization state perpendicular to the first polarization state, thereby further realizing light recovery and utilization. Optionally, the first light recovery component 631 can be a reflective polarization antireflection film (DBEF). A first light transmission device 632r is provided in the emission direction of the first light recovery component 631 to transmit the first beam to the first deflection element 633r without loss. In some embodiments, the first light transmission device can be a hollow light guide device, a square rod, or a conical rod, etc. The first deflection element 633r can be a solid right-angle prism to deflect the transmission direction of the first beam transmitted along the first direction to transmission along the second direction, thereby compressing the volume of the projection device along the second direction.

[0064] Furthermore, when the first folding element 633r adopts a hollow structure, it includes an incident surface, a reflecting surface, and an exiting surface. The incident surface and the exiting surface can be made of coated glass, quartz, or plastic, and their shapes can be straight planes, curved surfaces, or sawtooth surfaces composed of multiple straight planes. The two can be placed perpendicular to each other to meet the requirements for transmission and reflection of different light rays.

[0065] The angle between the reflecting surface of the first deflecting element 633r and the first direction can be any angle between -90° and 0°, so as to realize the deflection of light in any direction. Preferably, when the angle between the reflecting surface and the first direction is -45°, the light is deflected by 90°, thereby deflecting the direction of the first beam into the second direction. With this setting, the function of a right-angle prism can be realized.

[0066] Similarly, a third folding assembly is also provided between the third light source module and the third liquid crystal modulation module 23b. This assembly includes a third light recovery assembly 631b, a third light transmission device 632b, and a third folding element 633b. It is used to adjust the transmission direction of the third beam from the first direction to the opposite direction of the second direction. This arrangement, by changing the transmission direction of the first beam, compresses the length of the device along the opposite direction of the second direction. Simultaneously, the angle between the reflective surface of the third folding element 633b and the first direction can be any angle between 0° and 90°. The remaining arrangements are basically the same as those between the first light source module and the light combining module, and will not be described further here.

[0067] By reversing the transmission direction of the first beam transmitted along the first direction to the second direction and adjusting the transmission direction of the third beam from the first direction to the opposite direction of the second direction, the space along the first direction from the second light source module to the light combining device can be fully utilized, reducing the problem of excessive volume along the second direction caused by the arrangement of the first and third light source modules. At the same time, since the reversing component includes a light recovery component, a light transmission device, and a reversing element, the first beam can be transmitted to the liquid crystal modulation module efficiently and without loss, effectively improving the light utilization efficiency while reducing the size of the device.

[0068] Please see Figure 7 The schematic diagram shown is of the projection device 140 according to Embodiment 5 of this application. This embodiment is similar to... Figure 4The illustrated embodiment is similar, except that the light collection unit in this embodiment uses a second lens 142g. The second lens 142g is a collection lens used to collect the light emitted from the second light-emitting component and emit a collimated first beam under the collimation of the collimating lens. Since the surface distribution of the first beam emitted by the second lens 142g and the collimating lens is circular, while the part of the modulation panel that needs illumination is rectangular, it is necessary to cut a rectangle from the circular light spot. This application achieves light spot shaping and light recovery by setting a polarizer 241g with a special shape. Figure 8 As shown, the polarizer 241g includes a circular light spot distribution 2411g, a first region 2412g, and a second region 2413g. Preferably, the circular light spot distribution 2411g is the shape of the light spot when the first beam is transmitted to the modulation panel. The first region 2412g is a rectangular region adapted to the shape of the modulation panel and inscribed within the circular light spot. 2412g is configured as a light circulation film layer to perform polarization light circulation on the rectangular region of the first beam, for example, using the aforementioned DBEF, thereby maximizing system efficiency. The second region 2413g is located at the edge of the circular light spot distribution 2412g of the polarizer 241g, excluding the first region. The second region 2413g can employ a specular reflection film layer, so that the edge portion of the circular light spot that does not participate in illumination is reflected back to the second lens 142g for reuse, further improving light utilization efficiency.

[0069] With this setup, the first beam can be divided into a rectangular spot for illuminating the modulation panel and an edge spot for reflection and recovery. This allows for the recovery and reuse of light from different regions and with different polarization characteristics, both spatially and in terms of polarization, maximizing the light utilization efficiency of the light emitted from the light source module.

[0070] Please see Figure 9 The schematic diagram shown is of the projection device 150 according to Embodiment Six of this application. This embodiment is similar to... Figure 7 The illustrated embodiment is similar, except that in this embodiment, the second lens is a freeform lens, preferably an XY polynomial lens, and the collimating lens 153g is a Fresnel lens. Using a freeform lens as the second lens allows the emitted light to be distributed in a rectangular shape slightly larger than the illumination area of ​​the modulation panel, thus matching the required illumination portion of the panel. Therefore, the polarizer 251g is configured as follows: Figure 10The structure shown includes a circular rectangular light spot distribution 2511g, a first region 2512g, and a second region 2513g. Preferably, the circular rectangular light spot distribution 2511g is the shape of the light spot when the first beam is transmitted to the modulation panel. The first region 2512g is a rectangular region adapted to the shape of the modulation panel and inscribed within the circular rectangular light spot. 2512g is configured as a light circulation film layer to perform polarization light circulation on the rectangular region of the first beam, for example, using the aforementioned DBEF, thereby maximizing system efficiency. The second region 2513g is located at the edge of the circular rectangular light spot distribution 2512g of the polarizer 251g, excluding the first region. The second region 2513g can employ a specular reflection film layer, so that the edge portion of the circular light spot that does not participate in illumination is reflected back to the second lens for reuse, further improving light utilization efficiency. By employing a combination of freeform surface lenses and Fresnel lenses, the circular light spot can be shaped into a rectangular light spot, thereby reducing the area of ​​the edge region. Compared with Embodiment 5, this reduces the light loss efficiency of reflected light at the edge region, thus achieving higher light utilization efficiency.

[0071] Please see Figure 11 The schematic diagram shown is of the projection device 160 according to Embodiment 7 of this application. This embodiment is similar to... Figure 4 The embodiments shown are similar, except that: this embodiment also... Figure 4 Based on the illustrated embodiment two, an ultra-short-throw lens is incorporated, including a reflector 462 and a reflector cup 461, to deflect the illumination beam, thereby preventing the lens from becoming too long and increasing the system size. This projection device, by folding the light, increases space utilization and reduces the size of the projection device, effectively solving the problems of large size and high cost associated with lighting systems using direct-projection lenses. Furthermore, using an ultra-short-throw lens allows for a shorter distance from the projection device to the projection surface compared to the optical engine using a direct-projection lens, while maintaining the same transmittance. This reduces the space occupied by the projection device during user operation and improves the user experience.

[0072] Please see Figure 12 The schematic diagram shown is of the projection device 170 of Embodiment 8 of this application. This embodiment is similar to... Figure 9 as well as Figure 11 The embodiments shown are similar, except that: this embodiment also... Figure 9 Based on the fourth embodiment shown, ultra-short-throw lenses 472 and 471 are provided. Compared with the seventh embodiment, the structural layout of this embodiment can further utilize the space from the second light source module along the first direction to the lens, and further reduce the size of the projection device.

[0073] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0074] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A projection device, characterized in that, include: The light source module includes multiple light source modules, which are used to emit a first light beam, a second light beam, and a third light beam; A liquid crystal modulation module includes multiple liquid crystal modulation modules disposed in the output light path of the light source module. The multiple liquid crystal modulation modules are used to modulate the first light beam, the second light beam, and the third light beam emitted by the multiple light source modules into a first image light, a second image light, and a third image light, respectively. A light combining module is disposed in the outgoing light path of the plurality of liquid crystal modulation modules, and is used to combine the first image light, the second image light and the third image light to generate colored image light; A beam converging component is disposed between the light source module and the beam combining module, and is used to converge or partially converge the beam to achieve non-telecentric illumination. as well as A projection lens, disposed in the output light path of the light combining module, is used to image the image light onto a preset projection plane or screen to display the image; wherein, The plurality of liquid crystal modulation modules and the light combining module employ short-side light combining to reduce the back focal length of the projection lens; A polarizer includes a circular spot distribution, a first region, and a second region. The circular spot distribution is the shape of the light spot when the light beam is transmitted to the modulation panel. The first region is a rectangular region adapted to the shape of the modulation panel and inscribed within the circular spot distribution. The first region is configured as a light circulation film layer for polarizing the light spot in the rectangular region. The second region is disposed on the edge portion of the circular spot distribution excluding the first region. The second region is configured as a specular reflection film layer for recovering the edge light spot.

2. A projection device as described in claim 1, characterized in that, The light source module includes a first light source module, a second light source module, and a third light source module; The liquid crystal modulation module includes a first liquid crystal modulation module, a second liquid crystal modulation module, and a third liquid crystal modulation module. The second liquid crystal modulation module is disposed along a first direction in the output light path of the second light source module. The first liquid crystal modulation module is disposed along a second direction perpendicular to the first direction in the output light path of the first light source module. The third liquid crystal modulation module is disposed along the opposite direction of the second direction in the output light path of the third light source module. The light combining module is disposed along the first direction in the output light path of the second liquid crystal modulation module of the liquid crystal modulation module.

3. A projection device as described in claim 2, characterized in that, The liquid crystal modulation module includes a polarizer, a modulation panel, and an analyzer. The polarizer is used to polarize the light beam emitted by the light source module so that the polarization state of the light beam is parallel to the liquid crystal direction of the modulation panel. The analyzer is used to analyze the polarization of the light beam modulated by the modulation panel so that it can be recognized by the human eye.

4. A projection device as described in claim 3, characterized in that, The modulation panel is an LTP-LCD.

5. A projection device as described in claim 3, characterized in that, The first liquid crystal modulation module, the second liquid crystal modulation module, and the third liquid crystal modulation module each include a first modulation panel, a second modulation panel, and a third modulation panel. The long side of the second modulation panel is perpendicular to the first direction, parallel to the long side of the first and third modulation panels, and perpendicular to the short side of the light combining module.

6. A projection device as described in claim 2, characterized in that, The first, second, and third light source modules of the light source module each include a light-emitting unit, a light-collecting unit, and a collimating lens. The light-emitting unit is used to emit a light beam, the light-collecting unit is used to collect the light beam emitted by the light-emitting unit, and the collimating lens is used to collimate the light beam emitted by the light-collecting unit.

7. A projection device as described in claim 6, characterized in that, The light source module further includes a supplementary second light source module, which is arranged along a second direction and includes a supplementary second light-emitting unit along the second direction; wherein, The first light source module is arranged along the second direction, the second light source module is arranged along the first direction, and the third light source module is arranged along the opposite direction to the second direction. The supplementary light emitted from the supplementary second light source module is combined with the second light beam emitted from the second light source module and then irradiates the second liquid crystal modulation module.

8. A projection device as described in claim 7, characterized in that, A supplementary light-combining unit is provided on the common emission path of the second light-emitting unit and the supplementary second light-emitting unit in the second light source module. The supplementary light-combining unit is used to reflect the supplementary light beam emitted by the supplementary second light-emitting unit to the second light-emitting unit and transmit the second light beam emitted by the second light-emitting unit.

9. A projection device as described in claim 8, characterized in that, The reflective surface of the second light-emitting unit is coated with phosphor that emits the second light beam when excited, and the supplementary light beam is a blue laser.

10. A projection device as claimed in claim 6, characterized in that, The first light source module is arranged along a first direction, the second light source module is arranged along a first direction, and the third light source module is also arranged along a first direction. The first light beam emitted from the first light source module is deflected by the first deflection component and then incident on the first liquid crystal modulation module along a second direction. The light beam emitted from the third light source module is deflected by the third deflection component and then incident on the third liquid crystal modulation module in the opposite direction to the second direction.

11. A projection device as claimed in claim 10, characterized in that, The first deflection assembly includes a first light recovery assembly, a first light transmission device, and a first deflection element, used to adjust the transmission direction of the first light beam from a first direction to a second direction; The third deflection assembly includes a third light recovery assembly, a third light transmission device, and a third deflection element, used to adjust the transmission direction of the third beam from the first direction to the opposite direction of the second direction.

12. A projection device as claimed in claim 11, characterized in that, The first and third folding elements are hollow structures or solid right-angle prisms.

13. A projection device as described in any one of claims 6-12, characterized in that, The light collection unit is a cone-shaped reflector used to collect the light beam emitted by the light-emitting unit in a non-imaging manner.

14. A projection device as claimed in claim 6, characterized in that, The light collecting unit is a second lens, used to collect the light emitted from the second light-emitting component and emit a collimated first beam under the collimation of the collimating lens.

15. A projection device as claimed in claim 1, characterized in that, The projection lens is a non-telecentric ultra-short-throw lens, including a reflector and a reflector cup, used to deflect the illumination light emitted from the light combining module.

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