An LCD projector optical system

Abstract

The utility model discloses a LCD projector optical system, including setting in proper order according to the light ray advancing direction light source module, LCD screen, fresnel lens, reflector and projection lens, light source module includes light source, is provided with the light circulation subassembly behind the light source, is provided with the first lens before the light source, is provided with the polarizing brightening piece before the first lens, is provided with the second lens before the polarizing brightening piece, the absorption axis of polarizing brightening piece is parallelly matched with the upper polarizing film of LCD screen, is provided with reflector behind the fresnel lens, the reflector is obliquely arranged, is provided with projection lens behind the reflector. The utility model reaches the beneficial effect is: improves the light efficiency utilization through the light circulation subassembly setting.

Description

Technical Field

[0001] This utility model relates to the field of lens device technology, and in particular to an optical system for an LCD projector. Background Technology

[0002] As LEDs are widely used in projection displays, the problems associated with LED light sources are gradually gaining attention. LEDs have a near-Lambertian light distribution curve with an initial divergence angle of 120 degrees. To achieve collimated beam output, the light angle needs to be adjusted through a lens; however, this results in light energy loss at the edges, leading to a relative reduction in system luminous efficiency.

[0003] Therefore, the purpose of this invention is to achieve high effective light utilization in directional lighting applications such as projection lighting through the design of optical lenses. Utility Model Content

[0004] The purpose of this invention is to propose an optical system for an LCD projector that can improve light efficiency.

[0005] The purpose of this utility model is to provide an optical system for an LCD projector through the following technical solution, comprising a light source module, an LCD screen, a Fresnel lens, a reflector, and a projection lens arranged sequentially according to the direction of light travel; The light source module includes a light source, a light circulation component is disposed after the light source, a first lens is disposed before the light source, a polarizing brightening film is disposed before the first lens, and a second lens is disposed before the polarizing brightening film. The absorption axis of the polarizing brightening film is parallel and matched with the upper polarizing film of the LCD screen. A reflector is disposed after the Fresnel lens, the reflector is tilted, and a projection lens is disposed after the reflector.

[0006] Furthermore, the optical circulation assembly includes a reflector and a quarter-wave plate arranged sequentially; The light emitted from the light source passes through the first lens, from which natural light is emitted. This natural light then passes through the polarizing brightener, which emits S / P light and reflects P / S light. The reflected P / S light passes through a quarter-wave plate, becoming circularly polarized, and enters a reflector. The reflector reflects the circularly polarized light into a quarter-wave plate, which emits S / P light. In other words, the light changes as follows in the light circulation assembly: polarizing brightener reflects linearly polarized light → quarter-wave plate → circularly polarized light → reflector → circularly polarized light → passes through a quarter-wave plate again → linearly polarized light rotated 90°.

[0007] Furthermore, the reflector is a plane reflector, the optical axis of the Fresnel lens forms a 45° angle with the plane reflector, and the optical axis of the projection lens forms a 45° angle with the plane reflector.

[0008] Furthermore, an optical system for an LCD projector also includes heat-insulating polarizing glass, which is disposed parallel to the front of the LCD screen.

[0009] Furthermore, the light source base includes a base plate and side plates; The base plate of the light source base is provided with multiple grid-like structures for mounting the light source and the first lens. A light circulation assembly is mounted on the surface of the base plate of the light source base. The base plate of the light source base is perpendicularly welded to the side plate. The side plate includes a long fixing plate and a short fixing plate. A strip-shaped groove is provided between the main fixing plate and the secondary fixing plate to fit together. The long fixing plate and the short fixing plate can be slidably fixed and disassembled through the strip-shaped groove, thereby facilitating the replacement of the optical circulation component.

[0010] This utility model has the following advantages: This invention separates the polarized light by using a polarizing filter. The polarized light that is useful to the LCD screen is transmitted, while the polarized light that is not useful is reflected. The reflected light enters the reflector at the bottom of the light source module. The reflector reflects the light back and enters a quarter-wave plate. The polarized light that is reflected back is changed by the quarter-wave plate, so that it passes through the polarizing filter and is used by the LCD screen. Therefore, it significantly improves the lighting efficiency of the projector and saves power consumption. Meanwhile, by designing the light source base as an easily detachable structure, the quarter-wave plate can be replaced when it reaches the end of its service life, thereby extending the actual service life of the optical system of this invention and saving costs. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the optical system of this utility model; Figure 2 This is a schematic diagram of the optical path changes of this utility model; Figure 3 This is a schematic diagram of the light change in the light circulation component of this utility model; Figure 4 This is a schematic diagram of the projector assembly of this utility model; 1—Light source module, 2—LCD screen, 3—Fresnel lens, 4—Reflector, 5—Projection lens, 6—Heat-insulating polarizing glass, 11—Light source, 12—Light circulation assembly, 13—First lens, 14—Polarizing brightener, 15—Second lens, 16—Light source base. Detailed Implementation

[0012] The present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.

[0013] It should be noted that the orientation or positional relationship indicated by terms such as "left" and "right" is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this utility model is usually placed in during use, or the orientation or positional relationship that is commonly understood by those skilled in the art. Such terms are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0014] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other. Example

[0015] See Figure 1 This utility model provides an optical system for an LCD projector, including a light source module 1, an LCD screen 2, a Fresnel lens 3, a reflector 4, and a projection lens 5 arranged sequentially according to the direction of light travel; The light source module includes a light source 11, a light circulation component 12 is provided on the light source base 16 after the light source 11, a first lens 13 is provided in front of the light source 11, a polarizing brightening film 14 is provided in front of the first lens 13, and a second lens 15 is provided in front of the polarizing brightening film 14. The absorption axis of the polarizing brightening film 14 is parallel and matched with the upper polarizing film of the LCD screen 2. A reflector 4 is disposed after the Fresnel lens 3, the reflector 4 is tilted, and a projection lens 5 is disposed after the reflector 4.

[0016] Furthermore, the optical circulation assembly 12 includes a reflector 121 and a quarter-wave plate 122 arranged sequentially; The light emitted from the light source passes through the first lens 13, from which natural light is emitted. This natural light then passes through the polarizing brightener 14, which emits S / P light and reflects P / S light. The reflected P / S light passes through a quarter-wave plate 122, becoming circularly polarized, and enters a reflector 121. The reflector 121 reflects the circularly polarized light into a quarter-wave plate 122, which emits P / S light. The quarter-wave plate 122 then emits S / P light. In other words, the light changes in the light circulation assembly 12 as follows: polarizing brightener 14 reflects back linearly polarized light → quarter-wave plate 122 → circularly polarized light → reflector 121 → circularly polarized light → passes through the quarter-wave plate 122 again → linearly polarized light rotated by 90°.

[0017] Furthermore, the reflector 4 is a plane reflector, the optical axis of the Fresnel lens 3 forms a 45° angle with the plane reflector, and the optical axis of the projection lens 5 forms a 45° angle with the plane reflector.

[0018] Furthermore, an optical system for an LCD projector also includes a heat-insulating polarizing glass 6, which is disposed parallel to the front of the LCD screen.

[0019] This invention utilizes a combination of reflector 121 and quarter-wave plate 122 to form a light circulation assembly 12, which reuses the light reflected back from the polarizer. After passing through the polarizer, the S-ray emitted by the light source illuminates the LCD screen, while most of the P-ray is reflected back to the first lens 13 and the light circulation assembly 12 by the polarizer 14. The reflected P-ray then passes through the quarter-wave plate 122, enters the reflector 121, is reflected again, and then enters the quarter-wave plate 122, thus depolarizing the P-ray into linearly polarized light (P-ray + S-ray) before re-emission to the polarizer 14 for recycling. This significantly improves the light efficiency of the LCD projector.

[0020] like Figure 4 As shown, the light source base 16 includes a base plate and side plates; The base plate of the light source base 16 is provided with multiple grid-like structures for mounting the light source and the first lens. A light circulation assembly is mounted on the surface of the base plate of the light source base 16. The base plate of the light source base 16 is perpendicularly welded to the side plate. The side plate includes a long fixing plate and a short fixing plate. A strip-shaped groove is provided between the main fixing plate and the secondary fixing plate to fit together. The long fixing plate and the short fixing plate can be slidably fixed and disassembled through the strip-shaped groove, thereby facilitating the replacement of the optical circulation component 12.

[0021] The above embodiments only illustrate preferred implementation methods, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from this utility model, and these all fall within the protection scope of this utility model.

Claims

1. An optical system for an LCD projector, characterized by: The light source module, the LCD screen, the Fresnel lens, the reflector and the projection lens are sequentially arranged according to the light travel direction. The light source module comprises a light source, a light recycling assembly arranged on the light source base behind the light source, a first lens arranged in front of the light source, a polarized brightness enhancement film arranged in front of the first lens, and a second lens arranged in front of the polarized brightness enhancement film. The absorption axis of the polarized brightness enhancement film is parallel to the upper polarizing film of the LCD screen. The Fresnel lens is provided with a reflector, the reflector is arranged obliquely, and the reflector is provided with a projection lens.

2. An optical system for an LCD projector according to claim 1, wherein The light recycling assembly is detachably mounted on the light source base, and the light recycling assembly comprises a reflector and a quarter-wave plate arranged in sequence. The light emitted by the light source passes through the first lens, and the first lens emits natural light. The natural light passes through the polarized brightness enhancement film, the polarized brightness enhancement film emits S light / P light, and the reflected P light / S light passes through the quarter-wave plate to become circularly polarized light entering the reflector, the reflector reflects the circularly polarized light into the quarter-wave plate, and the quarter-wave plate emits S light / P light.

3. An optical system for an LCD projector according to claim 2, wherein The reflector is a plane reflector, the optical axis of the Fresnel lens forms a 45° angle with the plane reflector, and the optical axis of the projection lens forms a 45° angle with the plane reflector.

4. An optical system for an LCD projector according to claim 2, wherein Further comprising heat-insulating polarized glass, the heat-insulating polarized glass is arranged in parallel in front of the LCD screen.

5. An optical system for an LCD projector according to claim 2, wherein The base material of the quarter-wave plate is made of organic material.

6. An optical system for an LCD projector according to claim 1, wherein The light source base comprises a bottom plate and a side plate. The bottom plate of the light source base is provided with a plurality of grid-shaped mounting holes for mounting the light source and the first lens, and the light recycling assembly is mounted on the surface of the bottom plate of the light source base. The bottom plate and the side plate of the light source base are vertically welded. The side plate comprises a long fixed plate and a short fixed plate, a strip-shaped groove is arranged between the main fixed plate and the auxiliary fixed plate, and the long fixed plate and the short fixed plate can be slidably fixed and detached through the strip-shaped groove.

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