WO2020088163A1

WO2020088163A1 - Projection system and projection control method

Info

Publication number: WO2020088163A1
Application number: PCT/CN2019/108000
Authority: WO
Inventors: 胡飞; 陈晨; 郭祖强; 李屹
Original assignee: 深圳光峰科技股份有限公司
Priority date: 2018-11-02
Filing date: 2019-09-26
Publication date: 2020-05-07
Also published as: CN111147831A

Abstract

The present invention relates to a projection system and a projection control method, relating to the technical field of projection display. The projection system comprises: an illumination light modulator, used for modulating a received incident light beam on the basis of brightness distribution information of an image to be projected in order to obtain an illumination light beam, the brightness of at least one area of the illumination light beam being less than the brightness of the area corresponding to the incident light beam; and a silicon-based liquid crystal spatial light modulator, used for modulating the illumination light beam on the basis of image information of the image to be projected in order to obtain image light to be projected. Using the present invention can extend the service life of the projection system.

Description

Projection system and projection control method

Technical field

The invention relates to the technical field of projection display, in particular to a projection system and a projection control method.

Background technique

Liquid crystal on silicon (LCoS) chip display technology is a micro-display technology that combines semiconductor technology and liquid crystal display (LCD) technology.

However, since the silicon-based liquid crystal spatial light modulator under strong light conditions, free radicals may be generated in the liquid crystal and polyimide (PI) alignment layer in the chip, and the interaction of these free radicals changes the surface of the polyimide It can also cause the liquid crystal alignment to no longer meet the pre-designed conditions of the device, resulting in the loss of the spatial light modulation function of the silicon-based liquid crystal spatial light modulator, resulting in a shortened life of the silicon-based liquid crystal spatial light modulator, which in turn reduces the life of the entire projection system.

Summary of the invention

In order to solve the problem that the existing projection system based on the silicon-based liquid crystal spatial light modulator technology has a short service life of the silicon-based liquid crystal spatial light modulator, the present invention provides a projection system and a projection control method to extend the silicon-based liquid crystal spatial light modulation The service life of the device is short.

A first aspect of the present invention provides a projection system, including a light source device for forming an incident light beam, the projection system further includes: an illumination light modulator for receiving the incident light according to the brightness distribution information of the image to be projected The beam is modulated to obtain an illumination beam, and the brightness of at least one area of the illumination beam is less than the brightness of the corresponding area of the incident beam;

The silicon-based liquid crystal spatial light modulator is used to modulate the illumination beam according to the image information of the image to be projected to obtain image light to be projected.

A second aspect of the present invention provides a projection control method, which is applied to a projection system. The projection system includes a light source device for forming an incident light beam. The method includes:

Controlling the illumination light modulator to modulate the received incident beam according to the brightness distribution information of the image to be projected to obtain an illumination beam, and the brightness of at least one area of the illumination beam is less than the brightness of the corresponding area of the incident beam;

The silicon-based liquid crystal spatial light modulator is controlled to modulate the illumination beam according to the image information of the image to be projected to obtain image light to be projected.

Compared with the prior art, in the projection system of the present invention, the illumination light modulator provided is modulated according to the brightness distribution information of the image to be projected to obtain an illumination beam, and the brightness of at least one area of the illumination beam is less than the incident The brightness of the area corresponding to the light beam is used to reduce the intensity of the incident light beam, thereby completing the first-stage modulation. Thereafter, the provided silicon-based liquid crystal spatial light modulator modulates the illumination beam according to the image information of the image to be projected to obtain image light to be projected, and completes the second-level modulation. Since the illumination beam is illumination light that relatively reduces the light intensity of the incident beam, the intensity of light received by the silicon-based liquid crystal spatial light modulator can be reduced, thereby facilitating the extension of the silicon-based liquid crystal spatial light modulator Service life.

Further, since the illumination light beam emitted by the illumination light modulator can be dynamically adjusted, imaging of high dynamic range images can be achieved.

BRIEF DESCRIPTION

FIG. 1 is a flowchart of a projection control method according to an embodiment of the present invention.

2 is a schematic diagram of a projection system according to an embodiment of the invention.

3 is a schematic diagram of a projection system according to a specific embodiment of the present invention.

4-6 are schematic diagrams of the color wheel structure under various specific application examples provided by the present invention.

7 is a schematic diagram of an image to be projected provided by the present invention.

FIG. 8 is a pattern of illumination light obtained by modulating the image to be projected in FIG. 7 by the illumination light modulator.

FIG. 9 is an effect diagram of image light to be projected obtained by compensating and modulating the illumination light beam corresponding to the illumination light modulation pattern in FIG. 8.

10 is a schematic diagram of a projection system according to another embodiment of the present invention.

Symbol description of main components

Projection system

100, 200, 300

Illuminating light modulator 11

Silicon-based liquid crystal

spatial light modulators

12, 209, 309

Through yellow and

blue mirror

201, 301

Fluorescent

pink wheels

202, 302

Thin film transistor liquid crystal chip 203

The

first reflector

204, 306

Polarizers 205, 305

The second reflector 206

Light combiner 207, 307

Lens relay lens

210, 310

Polarizing beam splitter prism 208

First polarization beam splitter prism 303

Second polarization beam splitter prism308

Low-resolution silicon-based liquid crystal spatial light modulator 304

The following specific embodiments will further illustrate the present invention with reference to the above drawings.

detailed description

Referring to FIG. 1, FIG. 1 is a flowchart of a projection control method according to a preferred embodiment of the present invention, which can be applied to a projection system or a device including the projection system, such as a silicon-based liquid crystal micro laser projection, a silicon-based liquid crystal laser TV Wait. It should be noted that the projection control method according to the embodiment of the present invention is not limited to the steps and sequence in the flowchart shown in FIG. 1. According to different requirements, the steps in the flowchart shown can be added, removed, or changed in order.

As shown in FIG. 1, the projection control method of this embodiment may include the following steps:

Step 101: Control the illumination light modulator to modulate the received incident light beam according to the brightness distribution information of the image to be projected to obtain an illumination light beam. The brightness of at least one area of the illumination light beam is less than the brightness of the corresponding area of the incident light beam.

In this embodiment, the incident light beam is formed by the light source device of the projection device. The illumination light modulator determines modulation data according to the image information of the image to be projected, and the modulation data may include an illumination light modulation pattern. The illumination light modulation pattern may be a pattern in which brightness distribution information of an image to be projected is loaded on a preset pattern. The preset pattern may include a dark area and a non-dark area, and each image area obtained by the image to be projected according to a preset division method corresponds to each non-dark area in the preset pattern, if the image to be projected The brightness value of the image area in is lower than a preset brightness value, then the non-dark area corresponding to the image area is converted into the dark area to obtain the illumination light modulation pattern.

It can be understood that the effect of transforming the non-dark area corresponding to the image area into a dark area is that the brightness of at least one area of the illumination beam is less than the brightness of the corresponding area of the incident beam, and The number of converted areas coincides with the number of areas that are less than the brightness of the incident beam area.

In this embodiment, the brightness distribution information of the image to be projected may be information obtained based on each image area obtained by dividing the image to be projected in a preset division manner, and then performing brightness statistics on each image area, wherein, the The brightness statistical method may include taking the average value of brightness in each image area, or taking the maximum brightness value in each image area, or taking the minimum brightness value in each image area.

In this embodiment, the preset division method may include: 1), the image to be projected is at a preset resolution, one pixel is an image area; 2), the image to be projected is at a preset resolution Next, it is divided by the position of the pixel, and an image block composed of a plurality of adjacent pixels is an image area.

Corresponding to the preset division mode 1), one non-dark area of the preset pattern corresponds to one pixel; corresponding to the preset division mode 2), one non-dark area of the preset pattern corresponds to one image block. Therefore, when the brightness value of the pixel point or image block is lower than the preset brightness value, the non-dark area corresponding to the pixel point or image block can be converted into a dark area, and the local dimming effect is realized, thereby Making the preset pattern obtain the illumination light modulation pattern by loading the brightness information of the image to be projected, that is, removing the image information described by the pixels / image blocks corresponding to the non-dark area, and correspondingly, eliminating The light emitted corresponding to this part is reduced, thereby reducing the light intensity of the illumination beam irradiated to the liquid crystal on silicon-based spatial light modulator, which is beneficial to improving the service life of the subsequent liquid crystal on silicon-based spatial light modulator.

In this embodiment, the illumination light modulator may be any one of the following:

Thin film transistor liquid crystal chip (Thin Film Transistor-Liquid Crystal) (FTF-LCD), high temperature polycrystalline silicon liquid crystal chip (High Temperature Temperature Poly-Silicon Liquid Crystal Display (HTPS LCD), reflective low-resolution silicon-based liquid crystal spatial light modulator Crystal (Silicon, LCoS) and reflective digital micromirror modulator (Digital Micromirror Device, DMD). Wherein, the thin film transistor liquid crystal chip and the high-temperature polysilicon liquid crystal display chip are both transmissive light modulators.

Step 102: Control the silicon-based liquid crystal spatial light modulator to modulate the illumination beam according to the image information of the image to be projected to obtain image light to be projected.

In this embodiment, the image information of the image to be projected reflects the specific information description of the image. Therefore, the silicon-based liquid crystal spatial light modulator can modulate the received illumination light of the corresponding color into an image of the corresponding color according to the information Light, specifically, a modulation signal adapted to a silicon-based liquid crystal spatial light modulator can be obtained according to image information of an image to be projected, and the liquid crystal orientation in the silicon-based liquid crystal spatial light modulator is controlled according to the modulation signal, thereby controlling the illumination beam The polarized form of the light beam irradiated on the reflective layer of the liquid crystal on silicon liquid crystal modulator and reflected, thereby generating pixelated image light.

It can be understood that, the image light to be projected is a projection screen that can be presented on the corresponding light receiving surface because the image content of the image to be projected is consistent on the corresponding light receiving surface.

In this embodiment, the illumination light modulator is modulated according to the brightness distribution information of the image to be projected to obtain an illumination beam, and the brightness of at least one area of the illumination beam is less than the brightness of the corresponding area of the incident beam, in this way The light intensity of the incident light beam is reduced to complete the first-stage modulation. After that, the silicon-based liquid crystal spatial light modulator is controlled to modulate the illumination beam according to the image information of the image to be projected to obtain the image light to be projected, and the second-level modulation is completed. Since the illumination beam is illumination light that relatively reduces the light intensity of the incident beam, the intensity of light received by the silicon-based liquid crystal spatial light modulator can be reduced, thereby facilitating the extension of the silicon-based liquid crystal spatial light modulator Service life.

Further, since the illumination light beam emitted by the illumination light modulator can be dynamically adjusted, imaging display of high dynamic range images can be supported.

In this embodiment, in order to enable the image light to be projected after secondary modulation to be restored to a certain extent in brightness, the liquid crystal on silicon liquid crystal can also be determined according to the modulation data of the illumination light modulator Compensation modulation pattern of the modulator, and the liquid crystal on silicon spatial light modulator performs compensation modulation on the illumination beam according to the compensation modulation pattern so that the light amount of the image light to be projected and the light amount of the incident light beam are equal.

In this embodiment, the compensation modulation data includes modulating the light quantity of the image light to be projected by changing the turn-on time of the silicon-based liquid crystal spatial light modulator.

Referring to FIG. 2, FIG. 2 is a schematic diagram of a projection system according to an embodiment of the present invention. As shown in FIG. 2, the projection system 100 includes an illumination light modulator 11 and a silicon-based liquid crystal spatial light modulator 12. After receiving the incident light beam, the illumination light modulator 11 responds to the incident light according to the brightness distribution information of the image to be projected. The beam is modulated to obtain a corresponding illumination beam, and the brightness of at least one area of the illumination beam is less than the brightness of the corresponding area of the incident beam.

Wherein, the brightness distribution information of the image to be projected is information obtained by performing brightness statistics on each image area obtained by presetting the image to be projected. Specifically, the preset partitioning method and brightness statistical method can be used to Obtain the corresponding information, and will not repeat them here.

It can be understood that the illumination light modulator 11 determines modulation data according to the image information of the image to be projected, and the modulation data may include an illumination light modulation pattern. The illumination light modulation pattern may be a pattern in which brightness distribution information of an image to be projected is loaded on a preset pattern. The preset pattern may include a dark area and a non-dark area, and each image area obtained by the image to be projected according to a preset division method corresponds to each non-dark area in the preset pattern, if the image to be projected The brightness value of the image area in is lower than a preset brightness value, then the non-dark area corresponding to the image area is converted into the dark area to obtain the illumination light modulation pattern. Where no information is loaded, each non-dark area in the preset pattern corresponds to each image area in the image to be projected. Therefore, when the brightness information of the image to be projected is loaded: if the brightness value in the image area is lower than the preset brightness value, the non-dark area in the preset pattern corresponding to the image area is transformed into a dark area. It should be understood that during specific modulation, the above processing may be performed on multiple image regions simultaneously, and the processing speed should be greater than the frame rate of the image to be projected. Here, the preset brightness value may be adjusted according to circumstances and needs to be adjusted.

It can be understood that the incident light beam is preferably a three-primary-color light beam, which may be any one of the three-primary-color light beams, and may be a laser beam directly generated by a laser, or may be a phosphor layer that is emitted after being excited The fluorescent beam can also be a beam emitted by a light emitting diode. Corresponding to the three primary color beams, the projection system in this embodiment may include two illumination light modulators or three illumination light modulators, and each illumination light modulator may modulate one primary color beam or two primary color beams to generate corresponding Color lighting beam.

In this embodiment, the illumination light beam emitted by the illumination light modulator 11 is received by the liquid crystal on silicon liquid crystal spatial light modulator 12, and then the liquid crystal on silicon liquid crystal spatial light modulator 12 is used according to the image information of the image to be projected. The illumination beam is modulated to obtain image light to be projected.

It can be understood that the projection system 100 of this embodiment may include a single-chip silicon-based liquid crystal spatial light modulator or a multi-chip silicon-based liquid crystal spatial light modulator. In the case of a single-chip silicon-based liquid crystal spatial light modulator, and the silicon-based liquid crystal spatial light modulator modulates the illumination beams of the three primary colors, the illumination beams of each color can be modulated in time sequence to obtain the corresponding colors output in time sequence Of the image light to be projected, and after projection, the visual persistence effect of the human eye can be used to synthesize color images on the senses. Of course, the silicon-based liquid crystal spatial light modulator 12 can modulate only one primary color illumination beam, so the projection system can be provided with three silicon-based liquid crystal spatial light modulators to modulate the corresponding illumination beam, such as a silicon-based liquid crystal The spatial light modulator modulates the blue light illumination light, and the other two silicon-based liquid crystal spatial light modulators modulate the red light illumination and the green light illumination light, that is, the illumination beam of one color is composed of a silicon-based liquid crystal spatial light modulator To be modulated.

In an extended application example of this embodiment, the incident light beam is the first color light beam among the three primary color light beams, and accordingly, the illumination light modulator 11 modulates the received first color light beam to obtain The first illumination beam. It can be understood that the color of the first illumination beam at this time is still the first color.

In this extended application example, the projection system 100 includes the illumination light modulator 11 and the silicon-on-liquid crystal spatial light modulator 12 as well as a second illumination beam and a third illumination beam for conducting three primary colors of light. The first optical path component of the illumination light beam, and the first illumination light beam, the second illumination light beam, and the third illumination light beam are respectively three primary color illumination light beams of different colors, thereby supporting the realization of color image projection.

Further, in this extended application example, the projection system 100 may further include a laser light source and a color wheel, the color wheel is used to process the laser beam emitted by the laser light source to obtain the first color beam and The second-color beam and the third-color beam, of course, the first-color beam, the second-color beam and the third-color beam here are respectively three primary colors of different colors. Wherein, the color wheel may include three areas, namely a first area, a second area and a third area, the first area, the second area and the third area are periodically arranged in the beam of the laser On the propagation path, the first color light beam, the second color light beam and the third color light beam are generated in time sequence. Correspondingly, the second color beam and the third color beam can be processed to obtain the corresponding second beam and third beam, for example, a polarizer can be used to convert the second color beam to polarized light. In the same way, the second light beam uses a polarizer to perform polarization conversion on the third color light beam to obtain a third light beam. Here, the first color light beam may be a blue light beam, the second color light beam may be a red light beam, and the third color light beam may be a green light beam. After corresponding processing, the blue light beam is modulated into a lower-brightness blue illumination light beam, that is, the first illumination light beam; the red light beam is converted into a linearly polarized red light beam, that is, the second light beam ; The green light beam is converted into a green light beam with linear polarization, that is, the third light beam.

Specifically, the first area may be a reflection area that reflects the first color light beam or a transmission area that transmits the first color light beam, and the second area may be the second color light beam The third area may be the light conversion area of the third color light beam.

It can be understood that the purpose of defining the three primary colors here is to meet the color vision requirements in most situations. Therefore, in actual application, any one, multiple, or other synthetic colors other than the three primary colors can be selected. Above, using the illumination light modulator 11 and the silicon-based liquid crystal spatial light modulator 12 can obtain a projection image of a specific color, and since the illumination beam generated by the illumination light modulator 11 is a beam with a relatively lower average brightness, Therefore, the service life of the liquid crystal on silicon-based spatial light modulator 12 can also be prolonged.

In another extended application example of this embodiment, the incident light beam may also include a first color light beam, and the illumination light modulator 11 may be used to modulate the received first color light beam to obtain an illumination pattern. The first illumination beam. The difference from the previous extended application example is that the projection system 100 in this extended application example may include two silicon-based liquid crystal spatial light modulators, and the projection system may further include a light combiner and three primary colors for conducting light In the second optical path assembly of the second light beam and the third light beam, the first illumination light beam, the second light beam, and the third light beam are respectively three primary color light beams with different colors.

One silicon-based liquid crystal spatial light modulator is used to modulate the first illumination beam according to the image information of the image to be projected to obtain a first color monochromatic image light to be projected, while another silicon-based liquid crystal spatial light modulator is used The second light beam and the third light beam are modulated according to the image information of the image to be projected to obtain the second color monochrome image light to be projected and the third color monochrome image light to be projected in time sequence.

In another extended application example of this embodiment, the incident light beam may also include a first color light beam, and the illumination light modulator 11 is used to modulate the received first color light beam to obtain first illumination beam. The difference from the aforementioned extended application example is that: the projection system in this extended application example includes three silicon-based liquid crystal spatial light modulators, and the projection system may further include a light combiner and three primary colors for conducting light In the third optical path assembly of the second light beam and the third light beam, the first illumination light beam, the second light beam, and the third light beam are respectively three primary color light beams with different colors.

The at least one silicon-based liquid crystal spatial light modulator includes three pieces of silicon-based liquid crystal spatial light modulators, and each piece of silicon-based liquid crystal spatial light modulators is used for respectively corresponding to the first illumination beam, The second light beam and the third light beam are modulated to obtain a first color monochrome image light to be projected, a second color monochrome image light to be projected, and a third color monochrome image light to be projected. It can be understood that, when the monochromatic light of each color modulated by the three pieces of silicon-based liquid crystal spatial light modulators is processed by light combining and projected on the same plane at the same time, the corresponding color projection image can be synthesized.

In this embodiment, combined with the above-mentioned extended application example, it can be understood that, for single-liquid crystal liquid crystal spatial light modulators and multi-silicon liquid crystal spatial light modulators, it is beneficial to extend the service life and The number of illuminating light modulators can be related, that is: when the projection system includes an illuminating light modulator and a single-silicon liquid crystal spatial light modulator, the light intensity of the illuminating light beam modulated by the illuminating light modulator can be relative Reduce, which is conducive to extending the service life of the single silicon-based liquid crystal spatial light modulator; when the projection system includes two or more illumination light modulators, if there is a silicon-based liquid crystal space corresponding to the number of illumination light modulators Light modulator, and each illumination light modulator and each silicon-based liquid crystal spatial light modulator is only responsible for the modulation of the corresponding three primary color beams, then the light intensity of the illumination beam modulated by each illumination light modulator can be relatively reduced, so It is beneficial to prolong the service life of the corresponding silicon-based liquid crystal spatial light modulator.

It can be understood that, when the illumination light modulator 11 modulates the received light beam, if the preset brightness value set is larger, the light of the illumination beam obtained after loading the brightness distribution information of the image to be projected The larger the intensity can be reduced, the further it is beneficial to extend the service life of the liquid crystal on silicon liquid crystal spatial light modulator.

In this embodiment, the resolution of the illumination light modulator 11 is smaller than the resolution of the silicon-based liquid crystal spatial light modulator 12, so as to save costs.

In this embodiment, the time response of the illumination light modulator 11 is not lower than the frame rate of the image to be projected.

In this embodiment, the provided illumination light modulator modulates the brightness distribution information of the image to be projected to obtain an illumination beam, and the brightness of at least one area of the illumination beam is less than the brightness of the corresponding area of the incident beam. The light intensity of the incident light beam is reduced to complete the first-stage modulation. Thereafter, the provided silicon-based liquid crystal spatial light modulator modulates the illumination beam according to the image information of the image to be projected to obtain image light to be projected, and completes the second-level modulation. Since the illumination beam is illumination light that relatively reduces the light intensity of the incident beam, the intensity of light received by the silicon-based liquid crystal spatial light modulator can be reduced, thereby facilitating the extension of the silicon-based liquid crystal spatial light modulator Service life.

Refer to FIG. 3, which is a schematic diagram of a projection system according to a specific embodiment of the present invention. The illumination light modulator of this embodiment is a thin film transistor liquid crystal chip 203. Specifically, the light source device of the projection system 200 of this embodiment may include a yellow through blue mirror 201, a fluorescent pink wheel 202, a thin film transistor liquid crystal chip 203, and a polarizer器 205 Optical device. It should be understood that the yellow translucent mirror 201 can be equivalently replaced with other light guide devices after properly adjusting the optical path, such as the blue translucent mirror.

The light source of the light source device is a blue laser light source that emits a blue laser beam. After the blue laser beam is reflected by the yellow through blue mirror 201, the blue laser beam is reflected onto the fluorescent pink wheel 202. The fluorescent pink wheel 202 may include a first region, a second region, and a third region. The fluorescent pink wheel 202 is used to generate a red light beam, a green light beam, and a blue light beam in time sequence under the excitation of a blue laser beam.

4 to 6 are schematic diagrams of specific actual structures of fluorescent pink wheels in this embodiment. As shown in FIG. 4, the area A in the fluorescent pink wheel is the first area, and the areas provided on both sides of the area A are the red light conversion area and the green light conversion area. Here, the red light conversion area It is the second area, and the green light conversion area is the third area.

When the blue laser beam is irradiated on the area A, the area A will convert the received blue laser beam into a blue light beam; when the blue laser beam is irradiated on the red light conversion area, the red light conversion area will receive The blue laser beam is converted into a red light beam; when the blue laser is irradiated on the green light conversion area, the green light conversion area converts the received blue laser beam into a green light beam.

It can be understood that, since the converted blue light beam does not have linear polarization, the subsequent processing needs to set a corresponding polarizer to convert the polarized light.

In this embodiment, the area A may also be a scattering area for performing light scattering on the received blue laser beam, and in the process of performing light scattering, the polarization characteristics of light may not be changed.

As shown in FIG. 5, the area A in the fluorescent pink wheel is also the first area, and the areas provided on both sides of the area A are the red light conversion area and the green light conversion area, and the fluorescence in FIG. 4 The difference of the pink wheel structure is that the area A here is a transmission area for the blue laser beam irradiated onto the color wheel to directly pass through to obtain a blue light beam.

As shown in FIG. 6, the area A in the fluorescent pink wheel is the first area, and the areas provided on both sides of the area A are the red light conversion area and the green light conversion area, as shown in FIGS. 4 and 5. The difference in the structure of the fluorescent pink wheel in is that the area A here is a reflection area for reflecting the blue laser beam irradiated onto the fluorescent color wheel to obtain the blue light beam. It can be understood that the reflection angle of the blue laser beam irradiated onto the fluorescent pink wheel can be controlled by the angle of the reflecting surface on the fluorescent pink wheel, thus, the fluorescent pink wheel and other optical The installation position of the component and the light path setting are more flexible.

3, the first area of the fluorescent pink wheel 202 in FIG. 3 is a reflective area, so the blue laser beam can be emitted to the thin film transistor liquid crystal chip 203 under the reflection of the fluorescent pink wheel 202, the thin film transistor liquid crystal chip 203 The blue laser beam is modulated according to the brightness distribution information of the image to be projected to obtain a blue illumination beam. The generated blue illumination light beam is reflected by the first mirror 204. Here, a microstructure for eliminating laser coherence can also be provided in the first area to reduce the influence of speckle caused by the blue laser beam on the display. Of course, the thin film transistor liquid crystal chip 203 here can be replaced with a high temperature polysilicon liquid crystal chip or a digital micromirror modulator, and the resolution of the thin film transistor liquid crystal chip, high temperature polysilicon liquid crystal chip or digital micromirror modulator can be preferably Low-resolution devices to reduce the cost of the projection system; the response rate of the thin-film transistor liquid crystal chip, high-temperature polysilicon liquid crystal chip or digital micromirror modulator should be greater than the frame rate of the image to be projected, and the corresponding rate is considering the relative cost It should be as large as possible to reduce the chance of smearing on the projected image.

It can be understood that when the thin film transistor liquid crystal chip 203 is replaced with a digital micromirror modulator here, the reflection characteristics of the digital micromirror modulator can be directly used to modulate and reflect the corresponding light beam, so the first component can be omitted镜镜 204。 Mirror 204.

It can be understood that, after the blue-light illumination beam obtained by the reflection of the fluorescent pink wheel 202, a cylindrical lens can also be used to compensate the blue-light illumination beam to reduce the curvature effect caused by the fluorescent pink wheel 202.

At the same time, the red light beam and the green light beam generated by the fluorescent pink wheel 202 are transmitted through the yellow through blue mirror 201 and then exit to the position of the polarizer 205. The polarizer 205 is used to The green color light beam is subjected to polarization conversion processing to obtain red light beams and green light beams each having linear polarization. It can be understood that the red color beam and the green color beam generated by the fluorescent pink wheel 202 are unpolarized light, and thus the red color beam and the green color beam can be converted into linear polarized light by the polarizer 205 provided. Thereafter, the red light beam and the green light beam are reflected by the second reflecting mirror 206 to reflect the red light beam and the green light beam to the light receiving of the polarization splitting prism 208 (Polarizing Beam Splitter, PBS) Face side. Here, the red light beam, the green light beam after the polarization conversion process and the blue illumination light beam without the polarization conversion process are all beams with the first polarization state.

The polarization beam splitter prism 208 is disposed on the light incident surface side of the liquid crystal on silicon liquid crystal spatial light modulator 209, and is used to reflect the received light beam with the first polarization state to reflect to the liquid crystal on silicon liquid crystal space In the optical modulator 209, the light beam with the second polarization state obtained by the polarization deflection modulation of the liquid crystal on silicon-based spatial light modulator 209 is then transmitted. The first polarization state is the S polarization state, and the second polarization state is the P polarization state; of course, the first polarization state may be the P polarization state, and the second polarization state may be the S polarization state.

In this embodiment, the polarizer 205 may be a linear polarizer or a polarizing conversion system (PCS) composed of a polarization beam splitter prism and a broad-spectrum half-glass plate. For example, when the polarizer 205 is a polarization conversion system, during the deflection light conversion process: after the red color beam enters the polarization beam splitter prism, a part of the red color beam is directly transmitted to the broad-spectrum half-wave plate through an optical path, Another part of the red color light beam is reflected on the broad-spectrum half-wave plate by secondary reflection in another optical path, and the light exit direction that exits to the broad-spectrum half-wave plate through one optical path and exits to the broad-spectrum through another optical path The light exit directions of the half-wave plates are parallel. After that, the incident red light beam is deflected by 90 degrees through the broad-spectrum half-wave plate, and the red light beams of the two parts are kept parallel to obtain a red light beam.

It can be understood that, if it is preferable that the linear polarization of the blue illumination beam matches the incident polarization of the polarization beam splitter prism, it is beneficial to improve the utilization efficiency of the blue illumination beam.

The light combiner 207 receives the red light beam and the green light beam reflected by the second reflecting mirror 206 and the blue light illumination beam reflected by the first reflecting mirror 204 to guide the three primary color light beams to the same optical path for conduction, And it is transmitted to the polarization beam splitter 208 for reflection, so that the liquid crystal on silicon-based spatial light modulator 209 receives the corresponding light beam. The liquid crystal on silicon-based spatial light modulator 209 modulates the red light beam, the green light beam and the blue light illumination beam according to the image information of the image to be projected, so as to obtain the corresponding image light to be projected. The image light to be projected can be relayed through the lens relay lens 210 and finally emitted by the projection lens to obtain a projection image.

It can be understood that through the arrangement of the thin film transistor liquid crystal chip, the illumination beam of the light intensity can be relatively reduced, and thus the illumination intensity of the light beam irradiating the silicon-based liquid crystal spatial light modulator can be indirectly reduced, thereby helping to extend the silicon-based liquid crystal spatial light modulation The service life of the device.

In this embodiment, the liquid crystal on silicon spatial light modulator has different modulation patterns for illumination beams of different colors in the same image frame to be projected. Since the thin-film transistor liquid crystal chip is used to modulate blue light in this embodiment, the modulation pattern corresponding to the blue light beam is a compensation pattern relatively determined according to the illumination pattern of the thin-film transistor liquid crystal chip.

In this embodiment, the response frequency of the silicon-based liquid crystal spatial light modulator is greater than three times the response rate of the aforementioned low-resolution silicon-based liquid crystal spatial light modulator, as in the aforementioned low-resolution silicon-based liquid crystal spatial light modulator. When the response rate is greater than 60 Hz, the response rate of the high-resolution liquid crystal on silicon spatial light modulator here is greater than 180 Hz.

In this embodiment, due to the use of the better linear polarization of the laser, it is not necessary to provide a corresponding polarizer for the optical path of the blue light beam, which is beneficial to reduce the cost and the complexity of the projection system.

7 to FIG. 9, wherein FIG. 7 is a schematic diagram of an image to be projected provided by the present invention; FIG. 8 is a light modulation pattern for modulating the image to be projected in FIG. 7 using an illumination light modulator; FIG. 9 is FIG. 8 is an effect diagram of image light to be projected obtained by performing compensation compensation on the illumination beam corresponding to the modulation pattern in FIG. 8.

The modulation pattern in FIG. 8 is generated by performing brightness statistics on the image to be projected in FIG. 7, and after determining the modulation pattern, the liquid crystal on silicon liquid crystal spatial light modulator performs a light beam with a first polarization state according to the modulation pattern Polarization deflection pixel modulation.

It can be understood that the brightness of the image light obtained after the modulation pattern modulation is generally darker than the image to be projected, so the image obtained after the modulation effect can also be compensated and modulated. However, in this embodiment, the The blue light illumination beam is modulated, so only the modulation pattern corresponding to the blue light can be compensated and modulated.

As shown in FIG. 9, it is an effect diagram after compensating and modulating the illumination beam by the liquid crystal spatial light modulator on silicon. The image shown in FIG. 9 is a superposition of the image light after the compensation modulation of the blue light and the image light formed by modulating the red light beam and the green light beam, and the overall visual effect of the image is relatively bright.

It can be understood that the liquid crystal on silicon spatial light modulator may determine the compensation modulation pattern according to the modulation data of the illumination light modulator, that is, after the modulation pattern in FIG. 8 is determined, the compensation modulation pattern is relatively determined. The compensation pattern may make the obtained light quantity of the image light to be projected equal to the light quantity of the incident light beam, that is to say: the brightness of the image light to be projected from the compensation-modulated silicon-based liquid crystal spatial light modulator is not The brightness of the image light to be projected emitted by the silicon-based liquid crystal spatial light modulator modulated and not compensated by the illumination light modulator is consistent, so that the brightness is restored to the brightness of the image to be projected to a certain extent.

In this embodiment, the compensation modulation data includes modulating the light quantity of the image light to be projected by changing the turn-on time of the silicon-based liquid crystal spatial light modulator, that is, increasing the turn-on time to increase the displayed light flux and time Multiplied by, to achieve an increase in the amount of light.

Referring to FIG. 10, FIG. 10 is a schematic diagram of a projection system according to another embodiment of the present invention. The projection system 300 receives the blue laser beam and reflects the blue laser beam onto the fluorescent pink wheel 302 after being reflected by the yellow through blue mirror 301. The structure of the fluorescent pink wheel 302 may be the same as the structure of the fluorescent pink wheel 302 shown in FIG. 3, therefore, no further description will be given here.

In this embodiment, the first area in the fluorescent pink wheel 302 is a reflective area, so the blue laser beam can be emitted onto the first polarizing beam splitter 303 under the reflection of the fluorescent pink wheel 302. The first polarization beam splitting prism 303 reflects the received blue laser beam onto the low-resolution liquid crystal on silicon-based spatial light modulator 304, and the low-resolution liquid crystal on silicon-based spatial light modulator 304 according to the brightness distribution information of the image to be projected The blue laser beam is modulated to obtain a blue illumination beam. Here, a microstructure for eliminating laser coherence can also be provided in the first area to reduce the influence of speckle caused by the blue laser beam on the display.

At the same time, the red light beam and the green light beam generated by the fluorescent pink wheel 302 are transmitted through the yellow-transparent blue mirror 301 and then exit to the position of the polarizer 305. Similarly, the polarizer 305 is used for the red color beam and green The color beams are subjected to polarization conversion processing to obtain corresponding red beams and green beams. The red light beam and the green light beam are reflected by the first reflecting mirror 306 to reflect the red light beam and the green light beam to the optical path of the light combiner 307.

The light combiner 307 receives the red light beam and the green light beam reflected by the first reflecting mirror 306, and the blue illumination light beam emitted by the low-resolution liquid crystal on silicon-based spatial light modulator 304 to guide the three primary color light beams to Conducted on the same optical path and transmitted to the second polarization beam splitter prism 308, and then, through the second polarization beam splitter prism 308, the red light beam, the green light beam and the blue illumination light beam with the first polarization state are reflected to the silicon On the base liquid crystal spatial light modulator 309. The liquid crystal on silicon-based spatial light modulator 309 modulates the red light beam, the green light beam and the blue light beam on the basis of the image information of the image to be projected, so as to obtain the corresponding image to be projected. The received light beam is subjected to polarization deflection modulation, so that the emitted light beam is a light beam with a second polarization state (that is, the image light to be projected), and is transmitted by the second polarization beam splitter prism 308. In this embodiment, the first polarization state is the S polarization state, and the second polarization state is the P polarization state; of course, the first polarization state may be the P polarization state, and the second polarization state may be the S polarization state. Finally, the image light to be projected can be relayed through the lens relay lens 310 and finally emitted by the projection lens to obtain a projection image.

The above are only the embodiments of the present invention, and therefore do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the description and drawings of the present invention, or directly or indirectly used in other related technical fields, The same reason is included in the patent protection scope of the present invention.

Claims

A projection system includes a light source device for forming an incident light beam, characterized in that the projection system further includes:

An illumination light modulator, configured to modulate the received incident light beam according to the brightness distribution information of the image to be projected to obtain an illumination light beam, and the brightness of at least one area of the illumination light beam is less than the brightness of the corresponding area of the incident light beam;

The silicon-based liquid crystal spatial light modulator is used to modulate the illumination beam according to the image information of the image to be projected to obtain image light to be projected.
The projection system according to claim 1, wherein the brightness distribution information of the image to be projected is information obtained by performing brightness statistics on each image area obtained by presetting the image to be projected.
The projection system according to claim 1, wherein the liquid crystal on silicon spatial light modulator determines corresponding compensation modulation data according to the modulation data of the illumination light modulator to use the compensation modulation data to The illumination beam is compensated and modulated.
The projection system according to claim 3, wherein the compensation modulation data comprises modulating the light quantity of the image light to be projected by changing the on-time of the liquid crystal on silicon liquid crystal spatial light modulator.
The projection system of claim 1, wherein the incident light beam comprises a first color light beam, a second color light beam and a third color light beam, the first color light beam, the second color light beam and the The third color beams are three primary colors of different colors;

The illumination light modulator is configured to modulate the received first color light beam according to the brightness distribution information of the image to be projected to obtain a first illumination light beam;

The silicon-based liquid crystal spatial light modulator is used to modulate the first illumination beam, the second color beam and the third color beam respectively according to the image information of the image to be projected to obtain the image to be projected Light.
The projection system according to claim 5, wherein the light source device further comprises a laser light source and a color wheel, the color wheel is used to convert the laser beam emitted by the laser light source to generate the first color Light beam, the second color light beam and / or the third color light beam.
The projection system according to claim 6, wherein the color wheel is used to convert the laser beam emitted from the laser light source to generate the first color beam, the second color beam and the In the case of a third color light beam, the color wheel includes a first area, a second area, and a third area, and the first area, the second area, and the third area are periodically provided in the path of the laser beam propagation Above, the first color light beam, the second color light beam and the third color light beam are generated in time sequence;

Wherein, the first area is a reflection area that reflects the first color light beam or a transmission area that transmits the first color light beam, and the second area is a light conversion area of the second color light beam , The third area is a light conversion area of the third color light beam.
The projection system according to claim 7, wherein the laser beam emitted from the laser light source is a blue laser beam;

The first area reflects the blue laser beam; the second area converts the blue laser beam to obtain a red light beam, and the third area converts the blue laser beam to Get a green light beam.
The projection system according to claim 8, wherein the projection system further comprises a polarizer, and the polarizer is used to perform polarization conversion processing on the red light beam and the green light beam to obtain a uniform A red light beam and a green light beam having a first polarization state, the projection system further includes a polarization beam splitter prism disposed on the light incident surface side of the liquid crystal on silicon liquid crystal modulator, the polarization beam splitter prism is used for receiving The received light beam with the first polarization state is reflected, and the light beam with the second polarization state obtained by the polarization deflection modulation of the liquid crystal on silicon-based spatial light modulator is transmitted, wherein the first polarization state is The polarization direction of the second polarization state is perpendicular, and the liquid crystal on silicon-based spatial light modulator performs polarization deflection modulation on the light beam with the first polarization state reflected by the deflection dichroic prism.
The projection system according to claim 9, wherein the projection system further comprises a yellow-transparent blue mirror and a reflector, the yellow-transparent blue mirror is disposed between the color wheel and the polarizer The yellow transparent blue mirror is used to reflect the blue laser beam onto the color wheel, and to conduct the red light beam and the green light beam generated by the color wheel;

The reflecting mirror is disposed between the polarizer and the silicon-based liquid crystal spatial light modulator, and is used to reflect the red light beam and the green light beam onto the silicon-based liquid crystal spatial light modulator .
The projection system according to any one of claims 1 to 10, wherein the resolution of the illumination light modulator is smaller than the resolution of the silicon-based liquid crystal spatial light modulator.
The projection system according to claim 11, wherein the response rate of the illumination light modulator is not lower than the frame rate of the image to be projected.
A projection control method is applied to a projection system. The projection system includes a light source device for forming an incident light beam. The method is characterized in that the method includes:

Controlling the illumination light modulator to modulate the received incident beam according to the brightness distribution information of the image to be projected to obtain an illumination beam, and the brightness of at least one area of the illumination beam is less than the brightness of the corresponding area of the incident beam;

The silicon-based liquid crystal spatial light modulator is controlled to modulate the illumination beam according to the image information of the image to be projected to obtain image light to be projected.
The projection control method according to claim 13, wherein the brightness distribution information of the image to be projected is information obtained by performing brightness statistics on each image area obtained by presetting the image to be projected.