Liquid crystal projector and optical system thereof

Abstract

The utility model discloses a liquid crystal projector and an optical system thereof, the optical system of the liquid crystal projector comprises a light source, a liquid crystal panel and a liquid crystal light valve located between the light source and the liquid crystal panel, and the liquid crystal light valve is stacked on the liquid crystal panel; the liquid crystal panel comprises a plurality of display units which are uniformly arranged; the liquid crystal light valve comprises a plurality of light valve units which are in one-to-one correspondence with the display units; the light valve unit is configured to transmit or cut off light emitted from the light source to the corresponding display unit; according to the projector, the problem that the contrast ratio cannot be improved by partition dimming when an LED light source is matched with an LCD display screen in an existing projector can be solved.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, specifically to a liquid crystal projector and its optical system. Background Technology

[0002] Current single-LCD (Liquid Crystal Display) projectors primarily utilize high-power LED backlights. Light is focused through a condenser lens and then rectified by Fresnel lenses before being fed to the LCD as the image source. The image is then projected and magnified by a lens. However, LED light sources cannot be used with local dimming for LCD content display, thus limiting contrast. Utility Model Content

[0003] This application provides a liquid crystal projector and its optical system, which can alleviate the problem that current projectors using LED light sources and LCD displays cannot achieve local dimming to improve contrast.

[0004] This application provides an optical system for a liquid crystal projector. The optical system includes a light source, a liquid crystal panel, and a liquid crystal light valve located between the light source and the liquid crystal panel. The liquid crystal light valve is stacked on the liquid crystal panel.

[0005] The liquid crystal panel includes multiple display units arranged in a uniform manner, and the liquid crystal light valve includes multiple light valve units that correspond one-to-one with the display units; the light valve units are configured to transmit or block the light emitted from the light source to the corresponding display unit.

[0006] In some embodiments of the optical system of a liquid crystal projector, the light valve unit includes an upper polarizer, an upper electrode substrate, a liquid crystal layer, a lower electrode substrate, and a lower polarizer arranged sequentially, with the upper polarizer located near the light source side.

[0007] In some embodiments of the optical system of a liquid crystal projector, the light source includes a plurality of sub-light sources corresponding one-to-one with the display unit.

[0008] In some embodiments of the optical system of a liquid crystal projector, each display unit includes at least a first sub-pixel, a second sub-pixel, and a third sub-pixel.

[0009] In some embodiments of the optical system of the liquid crystal projector, the optical system further includes a first lens structure and a second lens structure, the first lens structure being located between the liquid crystal light valve and the light source, and the liquid crystal panel being located between the second lens structure and the liquid crystal light valve.

[0010] In some embodiments of the optical system of a liquid crystal projector, both the first lens structure and the second lens structure are Fresnel lenses.

[0011] In some embodiments of the optical system of the liquid crystal projector, the optical system further includes a projection lens located near the second lens structure; the projection lens is used to magnify and project the image displayed on the liquid crystal panel.

[0012] This application embodiment also provides a liquid crystal projector, which includes:

[0013] The optical system includes a light source and a liquid crystal panel.

[0014] A liquid crystal light valve is located between a light source and a liquid crystal panel, and is stacked on the liquid crystal panel. The liquid crystal panel includes multiple display units arranged in a uniform manner, and the liquid crystal light valve includes multiple light valve units that correspond one-to-one with the display units. The light valve units are configured to transmit or block the light emitted from the light source to the corresponding display unit.

[0015] In some embodiments of the liquid crystal projector, the light valve unit includes an upper polarizer, an upper electrode substrate, a liquid crystal layer, a lower electrode substrate, and a lower polarizer arranged sequentially, with the upper polarizer located near the light source side.

[0016] In some embodiments of the liquid crystal projector, the light source includes a plurality of sub-light sources corresponding one-to-one with the display unit.

[0017] This application provides a liquid crystal projector and its optical system. The optical system of the liquid crystal projector utilizes liquid crystal light valves laid on the liquid crystal panel. When the liquid crystal light valves are open, light emitted from the light source is transmitted through the liquid crystal light valves to the corresponding display units, illuminating the display units. When the liquid crystal light valves are closed, the light emitted from the light source is blocked by the liquid crystal light valves, thus preventing the display units blocked by the liquid crystal light valves from being illuminated. This achieves local dimming of the liquid crystal panel, thereby improving contrast. Attached Figure Description

[0018] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0019] Figure 1 This is a schematic diagram of the optical system of the liquid crystal projector provided in an embodiment of this application.

[0020] Figure 2 This is a schematic diagram of the structure of the light valve unit in the optical system of the liquid crystal projector provided in the embodiments of this application.

[0021] Figure 3 A schematic diagram of the switching state of the liquid crystal light valve in the optical system of the liquid crystal projector provided in the embodiments of this application.

[0022] Figure 4This is a structural block diagram of the liquid crystal light valve and liquid crystal panel in the optical system of the liquid crystal projector provided in the embodiments of this application.

[0023] Figure 5 This is a structural block diagram of the light source, liquid crystal light valve, and liquid crystal panel in the optical system of the liquid crystal projector provided in the embodiments of this application. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Features thus defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] Please see Figure 1 This embodiment provides an optical system for a liquid crystal projector. The optical system includes a light source 11, a liquid crystal panel 12, and a liquid crystal light valve 13 located between the light source 11 and the liquid crystal panel 12. The liquid crystal light valve 13 is stacked on the liquid crystal panel 12. The liquid crystal panel 12 includes a plurality of uniformly arranged display units 121, and the liquid crystal light valve 13 includes a plurality of light valve units 130 corresponding one-to-one with the display units 121. The light valve units 130 are configured to transmit or block the light emitted from the light source 11 to the corresponding display unit 121.

[0027] In this embodiment, a liquid crystal light valve 13 is installed on the liquid crystal panel 12 of the projector for each display unit 121. When the liquid crystal light valve 13 is open, the light emitted from the light source 11 is transmitted through the liquid crystal light valve 13 to the corresponding display unit 121, illuminating the display unit 121. When the liquid crystal light valve 13 is closed, the light emitted from the light source 11 is blocked by the liquid crystal light valve 13, so the area blocked by the liquid crystal light valve 13 cannot be illuminated. This achieves local dimming of the liquid crystal panel 12, thereby improving the contrast ratio.

[0028] Please refer to the following: Figure 2 and Figure 3In some embodiments, the light valve unit 130 includes an upper polarizer 131, an upper electrode substrate 132, a liquid crystal layer 133, a lower electrode substrate 134, and a lower polarizer 135 arranged sequentially, with the lower polarizer 135 located near the light source 11. In this embodiment, liquid crystal is encapsulated between the upper electrode substrate 132 and the lower electrode substrate 134 to form the liquid crystal layer 133, and a switch is encapsulated inside the substrate. When the switch is in the ON state, the light valve unit 130 is in the open state, and the light emitted by the light source 11 can illuminate the corresponding display unit 121 through the light valve unit 130, such as... Figure 2 As shown at point A, the corresponding display unit 121 is illuminated; when the switch is in the OFF state, the light valve unit 130 is in the closed state, and the light is cut off. Figure 2 As shown at point B, the display area corresponding to the light valve unit 130 cannot be illuminated, thereby achieving the purpose of dimming the LCD panel 12 zones and improving the display contrast.

[0029] Please refer to the following: Figure 4 Specifically, the image processing module 30 in the projector acquires the image signal. According to the signal requirements of the display image, when the image signal is not a black screen, it controls the light valve unit 130 to open, illuminating the corresponding display unit 121 in the LCD panel 12; when the image signal is a black screen signal, it controls the light valve unit 130 to close, and the light of the corresponding display unit 121 is completely blocked, thereby achieving the purpose of improving the display contrast.

[0030] Please refer to the following: Figure 5 In some embodiments, the light source 11 includes multiple sub-light sources 111, each corresponding to a display unit 121. That is, in this embodiment, the light source 11 is also partitioned, meaning each sub-light source 111 corresponds to one display unit 121, and each display unit 121 corresponds to one light valve unit 130. This allows for synchronized light control with the liquid crystal light valve 130 by controlling each sub-light source 111. For example, if the image processing module 30 in the projector calculates that there are many black areas in the image, the brightness of the light source 11 can be reduced synchronously, or the brightness of the sub-light sources 111 can be controlled according to the partitioning of the image area to save power.

[0031] In this embodiment, each display unit 121 includes at least a first sub-pixel, a second sub-pixel, and a third sub-pixel, which correspond to a red sub-pixel, a green sub-pixel, and a blue sub-pixel, respectively. Of course, in this embodiment, each display unit 121 may also include multiple sets of red, green, and blue sub-pixels, and this application does not limit this.

[0032] Please continue reading. Figure 1In some embodiments, the optical system further includes a first lens structure and a second lens structure. The first lens structure is located between the liquid crystal light valve 13 and the light source 11, and the liquid crystal panel 12 is located between the second lens structure and the liquid crystal light valve 13. In this embodiment, the first lens structure and the second lens structure are corresponding Fresnel lenses.

[0033] In some embodiments, the optical system further includes a projection lens located near the second lens structure. The projection lens is used to magnify and project the image displayed on the liquid crystal panel 12 onto a screen to achieve the projection function.

[0034] In this embodiment, a liquid crystal light valve 13 is added to the optical system of the projector. When the liquid crystal light valve 13 is open, the light emitted from the light source 11 is transmitted through the liquid crystal light valve 13 to the corresponding display unit 121, which is then illuminated. When the liquid crystal light valve 13 is closed, the light emitted from the light source 11 is blocked by the liquid crystal light valve 13, and the area blocked by the liquid crystal light valve 13 cannot be illuminated. This achieves local dimming of the liquid crystal panel 12, thereby improving the contrast ratio.

[0035] This application also provides a liquid crystal projector, which includes the aforementioned optical system and liquid crystal light valve. Specifically, the optical system includes a light source and a liquid crystal panel; the liquid crystal light valve is located between the light source and the liquid crystal panel, and is stacked on the liquid crystal panel; the liquid crystal panel includes a plurality of uniformly arranged display units, and the liquid crystal light valve includes a plurality of light valve units corresponding one-to-one with the display units; the light valve units are configured to transmit or block the light emitted from the light source to the corresponding display unit. In this application, by setting a liquid crystal light valve in the liquid crystal panel of the liquid crystal projector, when the liquid crystal light valve is open, the light emitted from the light source is transmitted through the liquid crystal light valve to the corresponding display unit, and the display unit is illuminated; when the liquid crystal light valve is closed, the light emitted from the light source is blocked by the liquid crystal light valve, so the area blocked by the liquid crystal light valve cannot be illuminated, thereby realizing the local dimming of the liquid crystal panel, thereby achieving the purpose of improving the display contrast of the projector.

[0036] In some embodiments, the light valve unit in the liquid crystal projector includes an upper polarizer, an upper electrode substrate, a liquid crystal layer, a lower electrode substrate, and a lower polarizer arranged sequentially, with the lower polarizer located near the light source. In this embodiment, liquid crystal is encapsulated between the upper and lower electrode substrates to form a liquid crystal layer, and a switch is encapsulated inside the substrate. When the switch is in the ON state, the light valve unit is open, and light emitted from the light source can pass through the light valve unit to illuminate the corresponding display unit, thus illuminating the corresponding display unit. When the switch is in the OFF state, the light valve unit is closed, and light is cut off, preventing the display area corresponding to the light valve unit from being illuminated. This achieves the purpose of local dimming of the liquid crystal panel, improving display contrast.

[0037] In some embodiments, the light source in the liquid crystal projector includes multiple sub-light sources, each corresponding to a display unit. That is, in this embodiment, the light source is also partitioned, meaning each sub-light source corresponds to one display unit, and each display unit corresponds to one light valve unit. This allows for synchronized light control with the liquid crystal light valve by controlling each sub-light source. For example, if the image processing module in the projector calculates that there are many black areas in the image, the brightness of the light source can be reduced synchronously, or the brightness of the sub-light sources can be controlled according to the partitioning of the image area to save power.

[0038] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0039] The liquid crystal projector provided in the embodiments of this application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An optical system for a liquid crystal projector, characterized in that, The optical system includes a light source, a liquid crystal panel, and a liquid crystal light valve located between the light source and the liquid crystal panel, wherein the liquid crystal light valve is stacked on the liquid crystal panel. The liquid crystal panel includes a plurality of uniformly arranged display units, and the liquid crystal light valve includes a plurality of light valve units corresponding one-to-one with the display units; the light valve unit is configured to transmit or block the light emitted by the light source to the corresponding display unit.

2. The optical system of the liquid crystal projector according to claim 1, characterized in that, The light valve unit includes an upper polarizer, an upper electrode substrate, a liquid crystal layer, a lower electrode substrate, and a lower polarizer arranged in sequence, with the lower polarizer located near the light source.

3. The optical system of the liquid crystal projector according to claim 1 or 2, characterized in that, The light source includes multiple sub-light sources that correspond one-to-one with the display unit.

4. The optical system of the liquid crystal projector according to claim 3, characterized in that, Each of the display units includes at least a first sub-pixel, a second sub-pixel, and a third sub-pixel.

5. The optical system of the liquid crystal projector according to claim 3, characterized in that, The optical system further includes a first lens structure and a second lens structure, wherein the first lens structure is located between the liquid crystal light valve and the light source, and the liquid crystal panel is located between the second lens structure and the liquid crystal light valve.

6. The optical system of the liquid crystal projector according to claim 5, characterized in that, Both the first lens structure and the second lens structure are Fresnel lenses.

7. The optical system of the liquid crystal projector according to claim 5, characterized in that, The optical system also includes a projection lens located near the second lens structure; the projection lens is used to magnify and project the image displayed on the liquid crystal panel.

8. A liquid crystal projector, characterized in that, The liquid crystal projector includes: An optical system, comprising a light source and a liquid crystal panel; A liquid crystal light valve is located between the light source and the liquid crystal panel, and the liquid crystal light valve is stacked on the liquid crystal panel; the liquid crystal panel includes a plurality of uniformly arranged display units, and the liquid crystal light valve includes a plurality of light valve units corresponding one-to-one with the display units; the light valve unit is configured to transmit or block the light emitted by the light source to the corresponding display unit.

9. The liquid crystal projector according to claim 8, characterized in that, The light valve unit includes an upper polarizer, an upper electrode substrate, a liquid crystal layer, a lower electrode substrate, and a lower polarizer arranged in sequence, with the upper polarizer located near the light source.

10. The liquid crystal projector according to claim 8 or 9, characterized in that, The light source includes multiple sub-light sources that correspond one-to-one with the display unit.

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