Double-LCD projector optical device

Abstract

The invention provides a double-LCD projector optical device, and relates to the technical field of projection display, the double-LCD projector optical device comprises a first light path module and a second light path module, the first light path module and the second light path module have the same structure, and each of the first light path module and the second light path module comprises a light source, a Fresnel lens group for beam shaping, an upper polarizer and an LCD which are sequentially arranged along the light path propagation direction. According to the invention, a double-LCD and double-light-path superposition mode is adopted, so that the brightness of the projector is doubled, and meanwhile, the defect that a single-LCD projector cannot realize a polarization 3D function is overcome.

Description

Technical Field

[0001] This invention relates to the field of projection display technology, and more specifically to an optical device for a dual LCD projector. Background Technology

[0002] With the development of display technology, users have placed higher demands on the brightness and 3D display functions of projectors. Currently, the main ways to improve projector brightness include increasing the power of a single light source or splicing multiple projectors. The former faces bottlenecks in heat dissipation and lifespan, while the latter is complex and costly.

[0003] In 3D display, active shutter technology requires high refresh rate display devices and expensive specialized glasses, and suffers from flickering issues. While some passive polarization 3D technologies (such as interlacing) reduce the cost of glasses, they sacrifice image resolution, resulting in viewing angle problems and "straightening" effects. Dual-LCD 3D display solutions, which use dual LCD projector optics, are limited in application due to their high cost and complex setup.

[0004] Therefore, the market urgently needs a 3D display solution that can efficiently improve brightness within a single system while providing high quality and controllable cost. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to provide a dual LCD projector optical device that can efficiently improve brightness in a single system while providing high-quality and cost-controllable 3D display.

[0006] To address the aforementioned problems, this invention provides an optical device for a dual LCD projector, comprising a first optical path module and a second optical path module. The first and second optical path modules have identical structures, each including a light source, a Fresnel lens group for beam shaping, an upper polarizer, and an LCD, arranged sequentially along the light propagation direction. A reflective polarizer is positioned at the intersection of the output optical paths of the first and second optical path modules. A projection lens is positioned on the output optical path of the reflective polarizer. The polarization direction of the upper polarizer in the first optical path module is orthogonal to the polarization direction of the upper polarizer in the second optical path module. The reflective polarizer is configured to reflect the light emitted from the first optical path module and transmit the light emitted from the second optical path module, causing the two light paths to overlap and superimpose on the incident light side of the projection lens.

[0007] Preferably, the first optical path module and the second optical path module each further include a light source heat sink for dissipating heat from the light source.

[0008] Preferably, the light source is an LED white light source.

[0009] The present invention has at least the following beneficial effects:

[0010] 1. This application uses a dual LCD and dual optical path superposition method, which doubles the brightness of the projector and also solves the defect that a single LCD projector cannot achieve polarized 3D function.

[0011] 2. By setting the polarization directions of the two polarizers to be orthogonal, and utilizing the reflection / transmission characteristics of a reflective polarizer to combine the light, the final projected image inherently carries the orthogonal polarization information of the two paths. This lays the physical foundation for flicker-free, low-cost, full-resolution passive polarized 3D displays.

[0012] 3. By using a single reflective polarizer and projection lens, the synthesis and projection of two beams are completed, making the entire optical engine structure simple, compact and stable, avoiding complex beam splitters or dual-lens systems, and reducing the difficulty and cost of assembly and adjustment. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the planar structure of the present invention.

[0015] The reference numerals in the attached figures are as follows:

[0016] 1. Projection lens; 2. Reflective polarizer; 3. Second Fresnel lens; 4. First LCD; 5. First upper polarizer; 6. First Fresnel lens; 7. First light source; 8. First light source heat sink; 9. Second light source heat sink; 10. Second light source; 11. Third Fresnel lens; 12. Second upper polarizer; 13. Second LCD; 14. Fourth Fresnel lens; 15. Vortex cooling fan. Detailed Implementation

[0017] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0018] Example:

[0019] See also Figure 1As shown in the embodiment of the present invention, a dual LCD projector optical device is provided, comprising a first optical path module and a second optical path module. The first and second optical path modules have the same structure, each including a light source, a Fresnel lens group for beam shaping, an upper polarizer, and an LCD arranged sequentially along the optical path propagation direction; a reflective polarizer 2 is disposed at the intersection of the output optical paths of the first and second optical path modules; a projection lens 1 is disposed on the output optical path of the reflective polarizer 2; wherein, the polarization direction of the upper polarizer in the first optical path module is orthogonal to the polarization direction of the upper polarizer in the second optical path module; the reflective polarizer 2 is configured to reflect the light emitted from the first optical path module and transmit the light emitted from the second optical path module, such that the two light paths overlap and superimpose on the incident light side of the projection lens 1.

[0020] In this embodiment, the first optical path module specifically includes a first light source 7, a first upper polarizer 5, a first LCD 4, and a Fresnel lens group (including a first Fresnel lens 6 and a second Fresnel lens 3); the second optical path module specifically includes a second light source 10, a second upper polarizer 12, a second LCD 13, and a Fresnel lens group (including a third Fresnel lens 11 and a fourth Fresnel lens 14).

[0021] Based on the above, in the first optical path module, the light emitted by the first light source 7 is straightened into a parallel beam by the Fresnel lens group and then becomes linearly polarized light (assuming it is P-polarized light) through the first upper polarizer 5. This P-polarized light illuminates the first LCD 4, and the first LCD 4 modulates the light according to the input first image signal to form P-polarized light carrying image information.

[0022] In the second optical path module, the light emitted by the second light source 10, after being straightened by the Fresnel lens group, becomes S-polarized light orthogonal to the P-polarized light after passing through the upper second polarizer 12. The S-polarized light is then modulated by the second LCD 13 to form S-polarized light carrying the second image signal.

[0023] Both polarized light beams are directed towards the reflective polarizer 2. The reflective polarizer 2 is configured such that its reflection axis is parallel to the P-ray direction and its transmission axis is parallel to the S-ray direction. Therefore, the P-polarized light from the first optical path is reflected by the reflective polarizer 2, deflected 90 degrees, and then directed towards the projection lens 1; while the S-polarized light from the second optical path passes directly through the reflective polarizer 2 and also reaches the projection lens 1. The two beams perfectly overlap at the entrance of the lens 1, superimposing to form a composite image with higher brightness and containing two orthogonal polarization components, which is ultimately projected onto the screen.

[0024] In 3D mode, the first LCD 4 and the second LCD 13 input parallax images corresponding to the left and right eyes, respectively. Users can view stereoscopic images by wearing polarized 3D glasses (the left lens transmits P-light, and the right lens transmits S-light).

[0025] This invention has a simple structure and significantly increases brightness. Furthermore, because the two light paths are polarized at 90-degree angles to each other, it achieves a polarized 3D effect when used with polarized 3D glasses.

[0026] Specifically, the first optical path module and the second optical path module each further include a light source heat sink for dissipating heat from the light source.

[0027] In this embodiment, refer to Figure 1 As shown, the first light source heat sink 8 and the second light source heat sink 9 respectively dissipate heat for the first and second optical path modules. It also includes a vortex cooling fan 15 installed below the reflective polarizer 2. The installation method and heat dissipation principle are well known to those skilled in the art and will not be described in detail. In a dual-optical-path system, this means double the heat source. The light source heat sink directly solves the problem of light source lifespan degradation and brightness reduction (light decay) caused by heat accumulation.

[0028] Specifically, the light source is an LED white light source.

[0029] In this embodiment, the LED white light source has advantages such as high brightness, long life, wide color gamut, and instant switching, making it very suitable for combination with a dual-light-path structure to maximize brightness advantages and 3D display effects.

[0030] It will be readily understood by those skilled in the art that the aforementioned advantageous methods can be freely combined and superimposed without conflict.

[0031] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above are merely preferred embodiments of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. An optical device for a dual LCD projector, characterized in that, It includes a first optical path module and a second optical path module. The first optical path module and the second optical path module have the same structure, both including a light source, a Fresnel lens group for beam shaping, an upper polarizer and an LCD arranged sequentially along the optical path propagation direction; A reflective polarizer is disposed at the intersection of the output optical paths of the first optical path module and the second optical path module; A projection lens is positioned on the output optical path of the reflective polarizer; The polarization direction of the upper polarizer in the first optical path module is orthogonal to the polarization direction of the upper polarizer in the second optical path module. The reflective polarizer is configured to reflect the light emitted from the first optical path module and transmit the light emitted from the second optical path module, so that the two light paths overlap and superimpose on the incident light side of the projection lens.

2. The optical device for a dual LCD projector according to claim 1, characterized in that: The first optical path module and the second optical path module each further include a light source heat sink for dissipating heat from the light source.

3. The optical device for a dual LCD projector according to claim 2, characterized in that: The light source is an LED white light source.

Images