Projector polarization intensifying system based on attaching 1 / 2 wave plate to bottom of PBS (Phosphate Buffer Solution) beam splitter prism

Abstract

The invention discloses a projector polarization intensifying system based on a PBS beam splitter prism with a 1 / 2 wave plate attached to the bottom, the projector polarization intensifying system comprises the PBS beam splitter prism and the 1 / 2 wave plate, a layer of high-precision 1 / 2 wave plate is attached to the bottom of the PBS beam splitter prism, and the thickness of the 1 / 2 wave plate enables the optical path difference between o light and e light to be just half wavelength lambda / 2. By optimizing the light path design, efficient conversion of polarized light is achieved, and the polarization purity and the output power of the projector are improved.

Description

Technical Field

[0001] The invention relates to the technical field of projection optical polarization, and in particular to a projector polarization light enhancement system based on a PBS beam splitter prism with a 1 / 2 wave plate attached to the bottom. Background Art

[0002] At present, among many projector products, low light efficiency conversion rate has always been an industry pain point, especially for projector LCD screens, which are widely used. However, the inherent spectral properties of the polarizer of the LCD screen prevent its optical efficiency from being fully utilized.

[0003] As an important optical component, polarization beam splitter (PBS) can split incident non-polarized light into two linearly polarized lights with mutually perpendicular polarization states. Half-wave plate can change the polarization direction of a light beam without changing its intensity and is widely used in optical adjustment and polarization control. Combining PBS with half-wave plate can significantly improve the performance of the optical system without increasing the complexity of the system. Summary of the invention

[0004] Purpose of the invention: The present invention provides a projector polarization light enhancement system based on a PBS beam splitter prism with a 1 / 2 wave plate attached to the bottom. By optimizing the optical path design, efficient conversion of polarized light is achieved, thereby improving the polarization purity and output power of the projector.

[0005] Technical solution: The present invention discloses a polarization light enhancement system for a projector based on a PBS beam splitter prism with a 1 / 2 wave plate attached to the bottom, comprising a PBS beam splitter prism and a 1 / 2 wave plate. A high-precision 1 / 2 wave plate is attached to the bottom of the PBS beam splitter prism, and the thickness of the 1 / 2 wave plate ensures that the optical path difference between the o-light and the e-light is exactly half a wavelength λ / 2.

[0006] Furthermore, it also includes an LED light source, a light bucket structure, a front Fresnel lens, a PBS beam splitter prism, a rear Fresnel lens, a PBS beam splitter film, P light, S light and a wave plate fast axis; when the light emitted by the LED light source is collimated by the light bucket structure and the front Fresnel lens and incident on the PBS beam splitter film through the PBS beam splitter prism, the P light is directly transmitted and the S light is reflected at an angle of 45 degrees. After the transmitted P light passes through the 1 / 2 wave plate attached to the bottom, the fast axis direction of the wave plate forms an angle of 45 degrees with the incident direction, and its polarization direction rotates 90 degrees. At this time, the polarization state of the P light is the same as that of the S light; subsequently, the two beams of S light with the same polarization state pass through the polarization device of the LCD screen to form a beam of light with consistent polarization state and enhanced intensity, which passes through the liquid crystal module, is focused by the rear Fresnel lens, and then is reflected by the reflector into the projection lens to form an image on the screen.

[0007] Furthermore, the 1 / 2 wave plate is made of a birefringent material.

[0008] Furthermore, the PBS beam splitter prism is composed of two precisely processed right-angle prisms, and a polarization beam splitting film is coated on the inclined surface of one of the prisms.

[0009] Furthermore, the size of the LED light source matches the diameter of the bottom port of the light bucket to ensure that the light completely enters the system.

[0010] Furthermore, the inner wall of the light bucket is an aluminum reflector, and the size of the front opening is consistent with the size of the front Fresnel lens and the size of the front surface of the PBS beam splitter prism.

[0011] Furthermore, the light is converted into P light and S light by the PBS spectroscopic film. The P light is transmitted, and the S light is reflected at an angle of 45 degrees to the reflective film on the side of the prism and then reflected at an angle of 45 degrees out of the bottom surface of the spectroscopic prism.

[0012] Furthermore, the light passing through the PBS beam splitter prism is consistent with the deflection angle of the polarization device on the LCD screen, which can maximize the light efficiency, ensure the consistency of the optical center of the entire system, and maximize the output power of the optical system.

[0013] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: the present invention ensures that the polarization state of the output light beam is highly consistent through the combination of PBS and 1 / 2 wave plate, thereby improving the polarization purity of the light beam; after the two beams of light with the same polarization state are combined, the intensity of the light beam is significantly enhanced, thereby improving the output power of the optical system; through simple structural design and optical path optimization, efficient conversion and combination of polarized light are achieved, thereby reducing the complexity of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of a part of the optical path structure of the present invention.

[0015] Figure 2 This is a schematic diagram of the structure of a PBS beam splitter prism with a 1 / 2 wave plate attached to the bottom of the PBS beam splitter prism of the present invention.

[0016] Figure 3 It is a schematic diagram of the structure of the projector of the present invention. DETAILED DESCRIPTION

[0017] like Figure 1 , Figure 2 and Figure 3 As shown, a projector polarization light enhancement system based on a PBS beam splitter prism with a 1 / 2 wave plate attached to the bottom thereof comprises: a PBS beam splitter prism 4 and a 1 / 2 wave plate 5. A layer of high-precision 1 / 2 wave plate 5 is attached to the bottom of the PBS beam splitter prism 4. The thickness of the 1 / 2 wave plate 5 makes the optical path difference between the o-light and the e-light just half a wavelength λ / 2. The PBS beam splitter prism 4 is used to decompose the incident light into two linearly polarized lights (P light and S light) with perpendicular polarization states.

[0018] When the light emitted by the LED light source 1 passes through the light bucket 2 structure, is collimated by the front Fresnel lens 3, and is incident on the PBS beam splitter film 8 through the PBS beam splitter prism 4, the P light 9 is directly transmitted, and the S light 10 is reflected at an angle of 45 degrees. After the transmitted P light passes through the 1 / 2 wave plate 5 attached to the bottom, the direction of the wave plate fast axis 11 forms an angle of 45 degrees with the incident direction, and its polarization direction is rotated 90 degrees. At this time, the polarization state of the P light 9 is the same as that of the S light 10; subsequently, the two beams of S light with the same polarization state pass through the polarization device of the LCD screen to form a beam of light with consistent polarization state and enhanced intensity, which passes through the liquid crystal module, is focused by the rear Fresnel lens 7, and is reflected by the reflector 12 into the projection lens 13 to form an image on the screen.

[0019] The present invention ensures that the polarization states of the output light beams are highly consistent through the combination of PBS and 1 / 2 wave plate, thereby improving the polarization purity of the light beams. After the two beams of light with the same polarization state are combined, the intensity of the light beams is significantly enhanced, thereby improving the output power of the optical system. Through simple structural design and optical path optimization, efficient conversion and combination of polarized light are achieved, thereby reducing the complexity of the system.

Claims

1. A projector polarization light enhancement system based on a PBS beam splitter prism with a 1 / 2 wave plate attached to the bottom, characterized in that: include: PBS beam splitter prism and 1 / 2 wave plate. A high-precision 1 / 2 wave plate is attached to the bottom of the PBS beam splitter prism. The thickness of the 1 / 2 wave plate makes the optical path difference between the o-light and the e-light just half a wavelength λ / 2.

2. The projector polarization light enhancement system based on the PBS beam splitter prism with a 1 / 2 wave plate attached to the bottom as claimed in claim 1, characterized in that: It also includes an LED light source, a light bucket structure, a front Fresnel lens, a PBS beam splitter prism, a rear Fresnel lens, a PBS beam splitter film, P light, S light and a wave plate fast axis; when the light emitted by the LED light source is collimated by the light bucket structure and the front Fresnel lens and incident on the PBS beam splitter film through the PBS beam splitter prism, the P light is directly transmitted and the S light is reflected at an angle of 45 degrees. After the transmitted P light passes through the 1 / 2 wave plate attached to the bottom, the fast axis direction of the wave plate forms an angle of 45 degrees with the incident direction, and its polarization direction rotates 90 degrees. At this time, the polarization state of the P light is the same as that of the S light; subsequently, the two beams of S light with the same polarization state pass through the polarization device of the LCD screen to form a beam of light with consistent polarization state and enhanced intensity, which passes through the liquid crystal module, is focused by the rear Fresnel lens, and then is reflected by the reflector into the projection lens to form an image on the screen.

3. The projector polarization light enhancement system based on the PBS beam splitter prism with a 1 / 2 wave plate attached to the bottom as claimed in claim 1, characterized in that: The 1 / 2 wave plate is made of birefringent material.

4. The projector polarization light enhancement system based on the PBS beam splitter prism with a 1 / 2 wave plate attached to the bottom as claimed in claim 2, characterized in that: The PBS beam splitter prism consists of two precisely machined right-angle prisms, one of which has a polarizing beam splitter coating on its inclined surface.

5. The projector polarization light enhancement system based on the PBS beam splitter prism with a 1 / 2 wave plate attached to the bottom as claimed in claim 2, characterized in that: The size of the LED light source matches the diameter of the bottom port of the light bucket.

6. The projector polarization light enhancement system based on the PBS beam splitter prism with a 1 / 2 wave plate attached to the bottom as claimed in claim 2, characterized in that: The inner wall of the light box is made of aluminum reflectors, and the size of the front opening is consistent with the size of the front Fresnel lens and the front surface size of the PBS beam splitter prism.

7. The projector polarization light enhancement system based on the PBS beam splitter prism with a half wave plate attached to the bottom as claimed in claim 2, characterized in that: The light is converted into P light and S light by the PBS spectroscopic film. The P light is transmitted, and the S light is reflected at a 45-degree angle onto the reflective film on the side of the prism and then reflected at a 45-degree angle out of the bottom surface of the spectroscopic prism.

8. The projector polarization light enhancement system based on the PBS beam splitter prism with a 1 / 2 wave plate attached to the bottom as claimed in claim 2, characterized in that: The light passing through the PBS beam splitter is consistent with the deflection angle of the polarization device on the LCD screen.

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