Double-LCD projector optical device
By using a dual LCD projector optical device, white LEDs and a PBS beam splitter are used to split light into two beams of linear off-axis light, which solves the problems of low light source utilization and high heat generation in existing LCD projectors, and achieves efficient light utilization and cost reduction.
Patent Information
- Application Number
- CN202420802526.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-17
- Publication Date
- 2025-01-07
- Estimated Expiration
- 2034-04-17
AI Technical Summary
Existing LCD projectors have low light source utilization and are prone to generating heat, while also being relatively expensive.
The optical device employs a dual-LCD projector, using white LEDs as the light source. The circular off-axis light is split into P and S-line off-axis light by a PBS beam splitter. The two LCDs improve light utilization efficiency, reduce heat, and lower costs.
It improves the utilization rate of light sources, reduces heat generation, and lowers costs.
Smart Images
Figure CN222319276U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of projection equipment, in particular to an optical device of a dual LCD projector. Background Art
[0002] In the current market, LCD projectors are divided into single-chip LCD projectors and three-chip LCD projectors. Because LCD can only pass off-axis light, half of the light flux of the light source cannot be used. Therefore, the single-chip LCD projector has a low utilization rate of the light emitted by the light source and is prone to heat generation. The three-chip LCD projector currently in use is relatively expensive.
[0003] Therefore, the utility model adopts a dual LCD projector optical path to solve the problem of low efficiency and high heat of a single LCD, and has a lower cost than a three-LCD projector. Utility Model Content
[0004] The utility model provides a dual LCD projector optical device to solve the problems of low utilization rate of light emitted by a light source, easy generation of heat and high cost in the application process of the existing LCD projector.
[0005] A dual LCD projector optical device includes an LED, a first condenser, a second condenser, a first PBS beam splitter, a first reflector, a first Fresnel lens, a first LCD, a second reflector, a second Fresnel lens, a second LCD, a second PBS beam splitter, a third Fresnel lens and a lens;
[0006] The light emitted by the LED1 is focused by the focusing system, and then the first PBS beam splitter splits the circular off-axis light emitted by the light source into P-line and S-line off-axis light;
[0007] The P-line de-axial light is incident on the second PBS beam splitter after passing through the first reflector, the first Fresnel lens and the first LCD; the S-line de-axial light is incident on the second PBS beam splitter after passing through the second reflector, the second Fresnel lens and the second LCD;
[0008] The second PBS beam splitter combines the P-line deflected light passing through the first LCD and the S-line deflected light passing through the second LCD into a beam of circular deflected light, and the circular deflected light is converged by the third Fresnel lens to project an image onto the screen through the lens.
[0009] Beneficial effects of the utility model:
[0010] The dual LCD projector optical device of the utility model uses white light LED as the light source, which has high light utilization and lower cost than using RGB light source, and does not need a light combining device of RGB light source.
[0011] In the dual LCD projector optical device of the utility model, the PBS can simultaneously utilize the light in the P and S directions of the circular off-axis light emitted by the LED, thereby improving the light utilization efficiency.
[0012] The dual-LCD projector optical device of the utility model adds a PBS beam splitter in the optical path to split the circular off-axis light of the light source into two beams of linear off-axis light, thereby doubling the picture brightness; the first PBS beam splitter is placed behind the second condenser to reduce the volume of the PBS and reduce the cost; the third Fresnel lens is placed behind the second PBS beam splitter, so that the two LCDs can share the same imaging system, which is beneficial to the combined screen effect of the two LCDs. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 This is a light path diagram of a dual LCD projector optical device described in the utility model.
[0014] In the figure: 1. LED, 2. first condenser, 3. second condenser, 4. first PBS beam splitter, 5. first reflector, 6. first Fresnel lens, 7. first LCD, 8. second reflector, 9. second Fresnel lens, 10. second LCD, 11. second PBS beam splitter, 12. third Fresnel lens, 13. lens. DETAILED DESCRIPTION
[0015] Combination Figure 1 To illustrate this embodiment, a dual LCD projector optical device is composed of an LED 1, a first condenser 2, a second condenser 3, a first PBS beam splitter 4, a first reflector 5, a first Fresnel lens 6, a first LCD 7, a second reflector 8, a second Fresnel lens 9, a second LCD 10, a second PBS beam splitter 11, a third Fresnel lens 12 and a lens 13;
[0016] The light emitted by the LED 1 is focused by the focusing system, and then the first PBS beam splitter 4 splits the circular off-axis light emitted by the light source into P-line and S-line off-axis light;
[0017] The P-line off-axis light passes through the first reflector 5, the first Fresnel lens 6 and the first LCD 7 and is incident on the second PBS beam splitter 11;
[0018] The S-line off-axis light passes through the second reflector 8, the second Fresnel lens 9 and the second LCD 10 and is incident on the second PBS beam splitter 11;
[0019] The second PBS beam splitter 11 combines the P-line deflected light passing through the first LCD 7 and the S-line deflected light passing through the second LCD 10 into a circular deflected light beam, which is converged by the third Fresnel lens 12 and then projected onto the screen through the lens 13 .
[0020] In this embodiment, the focusing system is composed of a first condenser 2 and a second condenser 3 ; the light emitted by the LED 1 is focused by the first condenser 2 and the second condenser 3 in sequence and then split by the first PBS beam splitter 4 .
[0021] In this embodiment, the wavelength range of the LED 1 is 380-760nm; the first condenser 2 and the second condenser 3 form a focusing system to focus the light emitted by the LED 1 and reduce the angle of the light emission; the first PBS beam splitter 4 divides the circular off-axis light emitted by the light source into P and S linear polarized light; the first reflector 5 and the second reflector 8 fold the light path to facilitate the subsequent linear polarized light synthesis; the first Fresnel lens 6 and the second Fresnel lens 9 collimate the light emitted by the focusing system; the first LCD 7 and the second LCD 10 have the same pixel size but have mutually perpendicular linear polarization angles; the second PBS beam splitter 11 is used to synthesize the two beams of linear polarized light divided by the first PBS beam splitter 4 into a beam of circular off-axis light; the third Fresnel lens 12 is used as the field lens of the optical system to improve the efficiency of light entering the lens 13; the lens 13 projects the image of the LCD onto the screen.
[0022] In this embodiment, the first reflector 5, the first Fresnel lens 6, the first LCD 7, the second reflector 8, the second Fresnel lens 9, and the second LCD 10 are mirror-arranged relative to the second PBS beam splitter 11; the distance between the LED 1 and the first condenser is 0.2 mm, the distance between the first condenser 2 and the second condenser 3 is 0.5 mm, the distance between the second condenser 3 and the first PBS beam splitter 4 is 15 mm, the distance between the first PBS beam splitter 4 and the first reflector 5 and the second reflector 8 are both 77 mm, the distance between the first reflector 5 and the first Fresnel lens 6, the distance between the second reflector 8 and the second Fresnel lens 9 are both 37 mm, the distance between the first Fresnel lens 6 and the first LCD 7, the distance between the second Fresnel lens 9 and the second LCD 10 are both 10 mm, the distance between the first LCD 7 and the second LCD 10 are both 29 mm from the second PBS beam splitter 11, and the distance between the second PBS beam splitter 11 and the lens 13 is 32-40 mm.
[0023] In this embodiment, the materials of the first condenser 2 and the second condenser 3 in the focusing system are PMMA, silicone or H-K9.
[0024] In this embodiment, the surfaces of the first reflector 5 and the second reflector 8 are plated with a high reflective film.
[0025] In this embodiment, the first PBS beam splitter 4 and the second PBS beam splitter 11 can be formed by spraying or chemical plating, or by pasting and fixing a PBS film on the surface.
[0026] In this embodiment, the first PBS beam splitter 4 is used to split the circularly polarized light into two linearly polarized light beams, thereby improving the light path efficiency, reducing the absorbed heat, and doubling the picture brightness. The first PBS beam splitter 4 is placed after the focusing system, which is beneficial to reducing costs.
[0027] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0028] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.
Claims
1. A dual LCD projector optical device, characterized in that: The optical device comprises an LED (1), a focusing system, a first PBS beam splitter (4), a first reflector (5), a first Fresnel lens (6), a first LCD (7), a second reflector (8), a second Fresnel lens (9), a second LCD (10), a second PBS beam splitter (11), a third Fresnel lens (12) and a lens (13); The light emitted by the LED (1) is focused by a focusing system, and then the circular off-axis light emitted by the light source is split into P-line and S-line off-axis light by a first PBS beam splitter (4); The P-line off-axis light passes through a first reflector (5), a first Fresnel lens (6) and a first LCD (7) and then enters a second PBS beam splitter (11); The S-line off-axis light passes through a second reflector (8), a second Fresnel lens (9) and a second LCD (10) and then enters a second PBS beam splitter (11); The second PBS beam splitter (11) combines the P-line deflected light passing through the first LCD (7) and the S-line deflected light passing through the second LCD (10) into a beam of circular deflected light, and the circular deflected light is converged by the third Fresnel lens (12) and then projected onto a screen through the lens (13).
2. The dual LCD projector optical device according to claim 1, characterized in that: The focusing system is composed of a first condenser (2) and a second condenser (3); the light emitted by the LED (1) is focused by the first condenser (2) and the second condenser (3) in sequence and then split by a first PBS beam splitter (4).
3. The dual LCD projector optical device according to claim 1, characterized in that: The first reflector (5) and the second reflector (8) are arranged to fold the light path for combining linearly polarized light.
4. The dual LCD projector optical device according to claim 1, characterized in that: The pixel sizes of the first LCD (7) and the second LCD (10) are the same, and the linear polarization angles of the first LCD (7) and the second LCD (10) are perpendicular to each other.
5. The dual LCD projector optical device according to claim 1, characterized in that: The wavelength range of the LED (1) is 380-760nm.
6. The dual LCD projector optical device according to claim 1, characterized in that: The first reflector (5), the first Fresnel lens (6), the first LCD (7), the second reflector (8), the second Fresnel lens (9), and the second LCD (10) are arranged in a mirror-like manner relative to the second PBS beam splitter (11).
7. The dual LCD projector optical device according to claim 1, characterized in that: The distance between the LED (1) and the first condenser (2) is 0.2 mm, the distance between the first condenser (2) and the second condenser (3) is 0.5 mm, and the distance between the second condenser (3) and the first PBS beam splitter (4) is 15 mm.
8. The dual LCD projector optical device according to claim 1, characterized in that: The distance from the first PBS beam splitter (4) to the first reflector (5) is equal to the distance from the first PBS beam splitter (4) to the second reflector (8); the distance from the first reflector (5) to the first Fresnel lens (6) is equal to the distance from the second reflector (8) to the second Fresnel lens (9); the distance from the first Fresnel lens (6) to the first LCD (7) is equal to the distance from the second Fresnel lens (9) to the second LCD (10); and the distance from the first LCD (7) to the second PBS beam splitter (11) is equal to the distance from the second LCD (10) to the second PBS beam splitter (11).
9. The dual LCD projector optical device according to claim 1, characterized in that: The materials of the first condenser (2) and the second condenser (3) in the focusing system are PMMA, silica gel or H-K9.
10. The dual LCD projector optical device according to claim 1, characterized in that: The surfaces of the first reflector (5) and the second reflector (8) are plated with a high-reflection film; the first PBS beam splitter (4) and the second PBS beam splitter (11) are fixed with the PBS film by spraying, chemical plating or surface bonding.