CN115236928A

CN115236928A - Projection device

Info

Publication number: CN115236928A
Application number: CN202211015218.5A
Authority: CN
Inventors: 李巍; 田有良; 顾晓强
Original assignee: Qingdao Hisense Laser Display Co Ltd
Current assignee: Qingdao Hisense Laser Display Co Ltd
Priority date: 2022-08-23
Filing date: 2022-08-23
Publication date: 2022-10-25
Anticipated expiration: 2042-08-23
Also published as: CN115236928B

Abstract

The application discloses projection equipment belongs to the photoelectric technology field. The first laser and the second laser which are emitted by the laser in the projection equipment and have different colors and polarization directions are emitted to the polarization beam splitting component; the polarization beam splitting component emits the first laser and the second laser along two directions respectively; the first laser and the second laser both penetrate through the light adjusting sheet to be emitted to the light valve, and the first laser and the second laser penetrate through the light adjusting sheet to be emitted to the polarization beam splitting component after being subjected to polarization direction change by the light valve; the light adjusting sheet adjusts the polarization direction of the laser except the target laser to counteract the change of the polarization direction of the light valve to the laser, and the target laser is the laser emitted to the light adjusting sheet from the first laser and the second laser; the polarization beam splitting component also emits the first laser and the second laser which are received from the light modulator to the lens, and emits the lasers except the first laser and the second laser to the outside of the lens; the lens projects the laser. The application solves the problem that the picture display effect of the projection equipment is poor. The application is used for projection display.

Description

Projection device

Technical Field

The application relates to the field of photoelectric technology, in particular to a projection device.

Background

With the development of the electro-optical technology, the requirements for the image display effect of the projection device are higher and higher. Laser light is increasingly used in light sources of projection apparatuses due to its advantages of better monochromaticity and higher brightness.

In the related art, a projection apparatus includes a laser light source, a plurality of light valves, and a lens. The laser light source can emit laser light with various colors, and the laser light with various colors respectively irradiates to the light valves; each light valve modulates the received laser based on the corresponding color component in the picture to be displayed and emits the modulated laser to the lens; and the lens projects the received modulated laser to form a projection picture.

However, characteristics of the laser light emitted by the laser light source may change in the process of transmitting the laser light to the light valve, so that a part of the laser light, which is incident into the laser light of the corresponding color and has one color, is mixed into the laser light of another color, and is further modulated by the light valve corresponding to the laser light of the another color and then is emitted out of the lens. Therefore, the proportion of each color component in a projection picture formed by the projection equipment can be deviated, so that the problem of color cast of the projection picture is caused, and the picture display effect of the projection equipment is poor.

Disclosure of Invention

The embodiment of the application provides a projection device, which can solve the problem that the picture display effect of the projection device in the prior art is poor. The projection apparatus includes: the device comprises a laser, a polarization beam splitting component, two dimming plates, two light valves and a lens;

the laser is used for emitting first laser and second laser with different colors and polarization directions, and the first laser and the second laser irradiate the polarization light splitting component;

the polarization light splitting component is used for emitting the received first laser and the second laser along two directions respectively, and a light adjusting sheet and a light valve are arranged in each direction of the two directions; the first laser and the second laser respectively penetrate through the dimming sheet in the emergent direction to emit to the light valve, are emitted back to the dimming sheet by the light valve, and penetrate through the dimming sheet to emit to the polarization beam splitting component;

for a light modulator and light valve in either of the two directions: the light valve is used for emitting the received laser after the polarization direction is changed; the light adjusting sheet is used for adjusting the polarization direction of the received laser except for the target laser to offset the change of the polarization direction of the light valve to the laser except for the target laser, and the target laser is the laser which is emitted out of the polarization splitting component along any direction in the first laser and the second laser;

the polarization beam splitting component is also used for emitting the first laser and the second laser received from the light modulator to the lens and emitting the laser except the first laser and the second laser received from the light modulator to the outside of the lens; the lens is used for projecting the incident laser to form a projection picture.

The beneficial effect that technical scheme that this application provided brought includes at least:

in the projection equipment of this application, the first laser and the second laser that the colour that the laser instrument sent and the equal difference of polarization direction can pass the light modulation piece directive light valve along different directions respectively through polarization beam splitting part, and these two kinds of laser are reemitted corresponding light modulation piece after modulating respectively by these two light valves to pass the light modulation piece directive polarization beam splitting part. Each light valve can change the polarization direction of the incident laser and emit the laser, and the light adjusting sheet can adjust the polarization direction of the laser except the received target laser to counteract the change of the polarization direction of the light valve to the laser, wherein the target laser is the laser emitted to the light adjusting sheet from the first laser and the second laser. Therefore, the polarization directions of the first laser and the second laser which are emitted to the polarization beam splitting component after passing through the light modulator and the light valve are changed, the first laser and the second laser can be transmitted in the direction different from the original transmission direction after being emitted to the polarization beam splitting component, and then are emitted to the lens by the polarization beam splitting component. The polarization direction of the laser except the first laser and the second laser after passing through the light modulator and the light valve is not changed, and the laser can return according to the original transmission direction after being shot to the polarization beam splitting component, so that the laser cannot be shot to the lens. Therefore, the laser mixed in the first laser and the second laser is prevented from being injected into the lens together with the first laser and the second laser, the filtering of other laser mixed in the first laser and the second laser is realized, the purity of the first laser and the second laser emitted by the lens can be improved, the proportion deviation of each color component in a projection picture is reduced, and the picture display effect of the projection equipment can be improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a projection apparatus provided in the related art;

FIG. 2 is a schematic structural diagram of a projection apparatus provided in an embodiment of the present application;

FIG. 3 is a schematic structural diagram of another projection apparatus provided in an embodiment of the present application;

fig. 4 is a schematic structural diagram of a laser provided in an embodiment of the present application;

FIG. 5 is a schematic structural diagram of another projection apparatus provided in an embodiment of the present application;

FIG. 6 is a schematic structural diagram of a projection apparatus according to another embodiment of the present application;

fig. 7 is a schematic structural diagram of another projection apparatus according to another embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

With the development of the optoelectronic technology, the laser is widely used in the projection device as a light source, and the requirement for the image display effect of the projection device is higher and higher. Fig. 1 is a schematic diagram of a partial structure of a projection apparatus provided in the related art. As shown in fig. 1, the projection apparatus may include a laser (not shown in fig. 1), a polarization splitting prism 001, a first light valve 002, a second light valve 003, and a lens 004. The laser light of a plurality of colors emitted from the laser in the projection apparatus is directed to the polarization splitting prism 001. For example, the laser may emit red laser light and green laser light, and the polarization direction of the red laser light is different from that of the green laser light. The laser light of different polarization directions is illustrated in fig. 1 by different patterns of dashed lines. The polarization beam splitter 001 has different transmittance and reflectance characteristics for the laser beams with different polarization directions, and as shown in fig. 1, the polarization beam splitter can transmit the laser beams with one polarization direction to the first light valve 002 and reflect the laser beams with the other polarization direction to the second light valve 003. The light valve can switch the polarization direction of the received laser light between the two polarization directions, so that the laser light emitted from the first light valve 002 can be reflected by the polarization beam splitter prism 001 to be incident on the lens, and the laser light emitted from the second light valve 003 can be transmitted by the polarization beam splitter prism 001 to be incident on the lens.

In an expected situation, because the polarization directions of the red laser light and the green laser light emitted by the laser devices are different, the red laser light and the green laser light can be split by the polarization splitting prism 001 to be respectively emitted into the first light valve 002 and the second light valve 003, for example, the red laser light is emitted to the first light valve 002, the green laser light is emitted to the second light valve 003, and then the laser light of the two colors is respectively modulated by the two light valves and then is projected through the lens 004. However, in practical situations, there is a problem that the laser light is depolarized during the transmission from the laser to the polarization splitting prism 001, that is, the polarization direction of part of the laser light is changed during the transmission. This causes the polarization directions of the red laser beams emitted to the polarization beam splitter prism 001 to be not completely matched, the polarization states of the green laser beams to be not completely matched, the polarization direction of a part of the red laser beams to be changed to be close to the polarization direction of the green laser beams, and the polarization direction of a part of the green laser beams to be changed to be close to the polarization state of the red laser beams. When the polarization splitting prism 001 splits the incident laser light based on the polarization direction, the portion of the green laser light whose polarization direction is changed is mixed into the red laser light and modulated by the first light valve 002 and projected through the lens 004, and the portion of the red laser light whose polarization direction is changed is mixed into the green laser light and modulated by the second light valve 003 and projected through the lens 004. Therefore, the proportion of each color laser emitted by the lens is deviated from the required proportion, and further the proportion of each color component in a projection picture formed by the projection equipment is deviated, so that the problem of color cast of the projection picture is caused, and the picture display effect of the projection equipment is poor.

The following embodiments of the present application provide a projection apparatus, which can achieve a high picture display effect.

Fig. 2 is a schematic structural diagram of a projection apparatus according to an embodiment of the present application. As shown in fig. 2, the projection apparatus 10 may include a laser 101, a polarization splitting component 105, two light adjusting sheets (e.g., a first light adjusting sheet 1031 and a second light adjusting sheet 1032), two light valves (e.g., a first light valve 1021 and a second light valve 1022), and a lens 104. For example, the polarization splitting part 105, the first dimming sheet 1031 and the first light valve 1021 may be sequentially arranged in a first direction (e.g., x-direction), and the polarization splitting part 105, the second dimming sheet 1032 and the second light valve 1022 may be sequentially arranged in a second direction (e.g., y-direction).

The laser 101 is a multicolor laser, the laser 101 can emit laser of multiple colors, for example, the laser 101 can emit a first laser and a second laser with different colors, and polarization directions of the first laser and the second laser are different, for example, the polarization direction of the first laser is a first polarization direction, and the polarization direction of the second laser is a second polarization direction. The first laser light and the second laser light may both be directed to the polarization splitting part 105. The polarization splitting member 105 has different transmission characteristics for the laser beams having different polarization directions, and the polarization splitting member 105 can emit the laser beams having different polarization directions in different directions. In the embodiment of the present application, the polarization splitting component 105 is configured to emit the received first laser light and the second laser light in two directions, for example, the first laser light is emitted in the first direction, and the second laser light is emitted in the second direction, so as to separate the first laser light and the second laser light.

The first laser and the second laser can respectively penetrate through the dimming sheets in the corresponding emergent directions to emit to the light valve, are modulated by the light valve to emit back the dimming sheets and penetrate through the dimming sheets to emit to the polarization light splitting component. As shown in fig. 2, the first dimming sheet 1031 and the first light valve 1021 are arranged in the first direction, and the second dimming sheet 1032 and the second light valve 1022 are arranged in the second direction. The first laser light passes through the first light adjusting plate 1031 to emit to the first light valve 1021, is emitted back to the first light adjusting plate 1031 by the first light valve 1021, and then passes through the first light adjusting plate 1031 to emit to the polarization beam splitting part 105. The second laser light passes through the second light modulating sheet 1032 toward the second light valve 1022, is emitted by the second light valve 1022 back to the second light modulating sheet 1032, and then passes through the second light modulating sheet 1032 toward the polarization splitting member 105.

For the dimming sheet and light valve in either of the two directions: the light valve is used for emitting the received laser after the polarization direction is changed; the light adjusting sheet is configured to adjust a polarization direction of the received laser light other than the target laser light to cancel a change in the polarization direction of the light valve to the laser light other than the target laser light, where the target laser light is the laser light that exits the polarization splitting component 105 in the first laser light and the second laser light along the any direction. The laser light other than the target laser light is separated by the polarization splitting unit 105 and transmitted along the same path as the target laser light but has a different color from the target laser light. The polarization beam splitting part 105 is also used for emitting the first laser light and the second laser light received from the light modulator to the lens 104, and for emitting the laser light other than the first laser light and the second laser light received from the light modulator to the outside of the lens 104. The lens 104 is used for projecting the incident laser light to form a projection screen.

In the embodiment of the present application, the first laser refers to the laser that passes through the first light valve 1021 and exits the lens 104 from the laser emitted by the laser 101; the second laser beam is the laser beam emitted by the laser 101, which passes through the second light valve 1022 and exits the lens 104. The laser 101 may also emit laser light other than the first laser light and the second laser light. If there is a part of the laser light emitted by the laser 101 that is not emitted to the first light valve 1021 or the second light valve 1022, or passes through the light valve but does not emit out of the lens 104, the part of the laser light does not belong to the first laser light and the second laser light. The color of the laser light other than the first laser light and the second laser light emitted by the laser 101 may be the same as the color of the first laser light or the second laser light.

Alternatively, the first light valve 1021 may correspond to a first color, and the first light valve 1021 is designed to transmit the laser light of the first color, and the first laser light may be the laser light of the first color. The second light valve 1022 may correspond to a second color, and the second light valve 1022 is designed to transmit the laser light of the second color. However, in practical applications, a portion of the laser light of the first color emitted by the laser 101 may be mixed with the second laser light and emitted to the second light valve 1022, and the portion of the laser light of the first color does not belong to the first laser light and does not belong to the second laser light. If a portion of the laser light of the second color emitted by the laser 101 may be mixed with the first laser light and emitted to the first light valve 1021, the portion of the laser light of the second color does not belong to the first laser light and does not belong to the second laser light. In the embodiment of the present application, it may also be considered that the laser light of the first color emitted by the laser 101 and incident on the first light valve 1021 is classified as the first laser light, and the laser light of the second color incident on the second light valve 1022 is classified as the second laser light; the light that enters the first light valve 1021 but is not of the first color and the light that enters the second light valve 1022 but is not of the second color are neither the first laser light nor the second laser light.

Optionally, in this embodiment, the first color includes red, and the second color includes blue and green, so that the first laser includes red laser and the second laser includes blue laser and green laser. Alternatively, the second color may include only either one of the blue laser light and the green laser light. Alternatively, the first color may include blue and green, and the second color may include red, so that the first laser includes blue and green lasers and the second laser includes red laser. Alternatively, the first color may include only either one of the blue laser light and the green laser light.

As in fig. 2, for the dimming sheet in the first direction (i.e., the first dimming sheet 1031), the target laser light is the first laser light. The first light valve 1021 may change the polarization direction of the received laser light (including the first laser light), such as changing the polarization direction of the first laser light from the first polarization direction to the second polarization direction. The first light adjustment sheet 1031 is used for adjusting the polarization direction of the received laser light (e.g., the laser light of the second color mixed in the first laser light) other than the first laser light, so as to counteract the change of the polarization direction of the laser light by the first light valve 1021. In this way, the polarization direction of the first laser light when re-emitted back to the polarization splitting part 105 is changed from the polarization direction when first emitted to the polarization splitting part 105; the polarization direction when the laser light other than the first laser light is re-emitted to the polarization splitting member 105 is not changed from the polarization direction when the laser light is emitted to the polarization splitting member 105 in the first direction.

For the dimming sheet in the second direction (i.e., the second dimming sheet 1032), the target laser is the second laser. The second light valve 1022 may change the polarization direction of the received laser light (including the second laser light), such as changing the polarization direction of the second laser light from the second polarization direction to the first polarization direction. The second light adjusting plate 1032 is used for adjusting the polarization direction of the received laser light other than the second laser light (e.g., the laser light of the first color mixed in the second laser light) to counteract the change of the polarization direction of the laser light by the second light valve 1022. In this way, the polarization direction of the second laser light when it is re-emitted to the polarization splitting unit 105 is changed from the polarization direction when it is first emitted to the polarization splitting unit 105; the polarization direction when the laser light other than the second laser light is re-emitted to the polarization splitting member 105 is not changed from the polarization direction when the laser light is emitted to the polarization splitting member 105 in the second direction.

Thus, when the first laser light and the second laser light pass through the light modulator and the light valve and are then emitted back to the polarization splitting unit 105, the first laser light and the second laser light can be transmitted along a path different from the original transmission path, and both the first laser light and the second laser light can be emitted to the lens 104 in the direction opposite to the second direction. When the laser light other than the first laser light and the laser light other than the second laser light after passing through the light modulator and the light valve are reflected back to the polarization beam splitting component 105, the laser light is required to return to the side of the laser 101 according to the original path, and the laser light is emitted to the lens 104 together with the first laser light and the second laser light. Therefore, the filtering of other laser beams mixed in the first laser beam and the second laser beam is realized, the purity of the first laser beam and the purity of the second laser beam emitted by the lens can be improved, the proportion deviation of each color component in a formed projection picture is reduced, and the picture display effect of the projection equipment can be further improved.

The modulation of the received laser light by the first and second

light valves

1021, 1022 may each include: the laser light is subjected to polarization direction change. For example, the modulation of the first laser light by the first light valve 1021 includes switching the polarization direction of the first laser light from the first polarization direction to the second polarization direction, and the modulation of the second laser light by the second light valve 1022 includes switching the polarization direction of the second laser light from the second polarization direction to the first polarization direction. The modulation of the laser light by the light valve may include other processes besides polarization direction switching, for example, the modulation may also include adjusting the amount of light emitted from each position in the light valve. In the embodiments of the present application, a device is used to implement a function, which means that the device is designed to precisely implement the function, and the result obtained in actual operation has a certain error from an expected standard result. For example, the light valve is designed to rotate the polarization direction of the laser light by 90 degrees, which means that the polarization direction of the laser light is originally designed to be rotated by 90 degrees in a standard manner, but the light valve is also designed to rotate the polarization direction of the laser light by 90 degrees if the light valve can only rotate the polarization direction of the laser light by 89 degrees or by another angle having a certain deviation from 90 degrees due to manufacturing process errors or other reasons during actual implementation.

Optionally, in this embodiment of the application, the time when the laser 101 emits the first laser light and the time when the laser 101 emits the second laser light may coincide, and the first light valve 1021 and the second light valve 1022 may modulate the incident laser light simultaneously based on one frame of image to be displayed, so that the modulation efficiency of the light valves on the laser light may be improved. Alternatively, each of the first and second

light valves

1021 and 1022 may modulate all of the laser light incident thereto.

To sum up, in the projection apparatus provided in the embodiment of the present application, the first laser and the second laser that are different in color and polarization direction and emitted by the laser device may respectively pass through the light modulation sheet to the light valves along different directions through the polarization splitting component, and the two light valves respectively modulate the two lasers and then emit the two lasers back to the corresponding light modulation sheet so as to pass through the light modulation sheet to emit the two lasers to the polarization splitting component. Each light valve can change the polarization direction of the incident laser and emit the laser, and the light adjusting sheet can adjust the polarization direction of the laser except the received target laser to counteract the change of the polarization direction of the light valve to the laser, wherein the target laser is the laser emitted to the light adjusting sheet from the first laser and the second laser. Therefore, the polarization directions of the first laser and the second laser which are emitted to the polarization beam splitting component after passing through the light modulator and the light valve are changed, the first laser and the second laser can be transmitted in the direction different from the original transmission direction after being emitted to the polarization beam splitting component, and then are emitted to the lens by the polarization beam splitting component. The polarization direction of the laser except the first laser and the second laser after passing through the light modulator and the light valve is not changed, and the laser can return according to the original transmission direction after being emitted to the polarization light splitting component, so that the laser cannot be emitted to the lens. Therefore, the laser mixed in the first laser and the second laser is prevented from being injected into the lens together with the first laser and the second laser, the filtering of other laser mixed in the first laser and the second laser is realized, the purity of the first laser and the second laser emitted by the lens can be improved, the proportion deviation of each color component in a projection picture is reduced, and the picture display effect of the projection equipment can be improved.

As shown in fig. 2, the polarization splitting member 105 may have a cubic shape, and the polarization splitting member 105 may be a Polarization Beam Splitter (PBS). The polarization splitting prism can comprise two right-angle prisms with opposite inclined surfaces, and a polarization splitting dielectric film is arranged between the inclined surfaces of the two right-angle prisms. For example, the inclined surfaces of the two right-angle prisms can be glued, and the inclined surface of one of the right-angle prisms is coated with a polarization splitting medium film. Optionally, fig. 3 is a schematic structural diagram of another projection apparatus provided in this embodiment of the present application. As shown in FIG. 3, the Polarization splitting member 105 may be a sheet, for example, the Polarization splitting member 105 may be a Wire-grid Polarization Beam splitter (Wire-grid PBS).

For example, the polarization splitting part 105 may transmit light of a first polarization direction and reflect light of a second polarization direction. The first laser beam emitted by the laser 101 may transmit through the polarization splitting part 105, and the second laser beam may be reflected on the polarization splitting part 105, so that the first laser beam and the second laser beam emitted by the laser 101 may be separated. As shown in fig. 2 and 3, the first laser light and the second laser light emitted from the laser 101 both emit to the polarization beam splitting component 105, and the first laser light is transmitted by the polarization beam splitting component 105 and then emitted to the first light adjusting plate 1031 and the first light valve 1021. The second laser light is reflected by the polarization splitting element 105 and directed to the second dimming sheet 1032 and the second light valve 1022.

With continued reference to fig. 2 and fig. 3, the first light valve 1021 and the second light valve 1022 may be respectively located at two adjacent sides of the polarization splitting component 105. The side of the polarization beam splitting part 105 receiving the laser light emitted from the laser 101 is opposite to the side of the first light valve 1021. The side on which the lens 104 is located is opposite to the side on which the second light valve 1022 is located. The first light valve 1021 and the first light adjusting plate 1031 can emit the modulated first laser light back to the polarization splitting member 105, and the polarization direction of the modulated first laser light is the second polarization direction, so that the polarization splitting member 105 can reflect the modulated first laser light to direct the first laser light to the lens 104. The second light valve 1022 and the second light adjusting plate 1032 may emit the modulated second laser light back to the polarization splitting part 105, and the polarization direction of the modulated second laser light is the first polarization direction, so the polarization splitting part 105 may transmit the modulated second laser light so that the second laser light is emitted to the lens 104.

Alternatively, the first polarization direction may be perpendicular to the second polarization direction, for example, the laser light with the first polarization direction may be P-polarized light, and the laser light with the second polarization direction may be S-polarized light. Illustratively, the first light valve 1021 and the second light valve 1022 in the projection apparatus 10 are each configured to rotate the polarization direction of the received laser light by 90 degrees, so as to switch the corresponding target laser light between P-polarized light and S-polarized light. The first and

second dimming sheets

1031 and 1032 are each configured to rotate the polarization direction of the received laser light other than the target laser light by 90 degrees. Therefore, after passing through the light valve and the light adjusting plate, the polarization direction of the laser rotates by 180 degrees and is changed back to the original polarization direction, namely the polarization direction is unchanged.

Illustratively, the first light valve 1021 and the second light valve 1022 may each include liquid crystal on silicon LCOS. The LCOS can change the polarization direction of the incident laser light under the control of the driving circuit. For example, the LCOS may be used to rotate the polarization direction of incident laser light by 90 degrees, and the LCOS may adjust incident P-polarized light to S-polarized light or may adjust incident S-polarized light to P-polarized light. The LCOS in the first light valve 1021 is used to change the polarization direction of the incident first laser light from the first polarization direction to the second polarization direction, and the LCOS in the second light valve 1022 is used to change the polarization direction of the incident second laser light from the second polarization direction to the first polarization direction.

Each of the first and

second dimming plates

1031 and 1032 may include a half-wave plate, and the half-wave plate may deflect the polarization direction of light of the corresponding wavelength passing therethrough by 90 degrees. The half-wave plate may be a half-wave plate only for the laser light other than the target laser light, that is, only the laser light other than the target laser light is used for polarization direction adjustment, and the half-wave plate may not be used for the target laser light.

For example, the first light adjustment plate 1031 includes a half-wave plate for light of a different color than the first laser light, such as a half-wave plate for light of a color other than the first color; the second dimming plate 1032 comprises a half-wave plate for light of a different color than the second laser light, such as a half-wave plate for light of a color other than the second color. In the embodiment of the present application, the laser 101 may emit only the laser light of the first color and the laser light of the second color, and only the laser light of the second color may be mixed into the first laser light, and only the laser light of the first color may be mixed into the second laser light. The first light adjustment plate 1031 may include a half-wave plate for the same light as the second laser light color (i.e., light of the second color), and the second light adjustment plate 1031 includes a half-wave plate for the same light as the first laser light color (i.e., light of the first color). The adjustment of the polarization direction of light by the wave plate can be realized based on the relation between the thickness of the wave plate and the wavelength of the light. The thickness of the half-wave plate may differ by one-half of the wavelength from an integer multiple of the wavelength of the light it is used to tune.

In an alternative implementation, the light modulation sheet is a half-wave plate, the light modulation sheet acts on the incident light by using all the structures of the light modulation sheet, and the overall thickness of the light modulation sheet and the wavelength of the light satisfy the relationship. For example, the thickness of the first dimming sheet 1031 is (m + 1/2) times the center wavelength of the second laser light, the thickness of the second dimming sheet 1032 is (n + 1/2) times the center wavelength of the first laser light, and m and n are both natural numbers. Optionally, the thickness of the dimming sheet may also deviate from this multiple, for example, the deviation may be less than or equal to 15%. The thickness of the first light adjustment sheet 1031 is between (m + 1/2) × (1-a) times and (m + 1/2) × (1+a) times the center wavelength of the second laser light, m is a natural number, and a =0.15; the thickness of the second dimming sheet 1032 is between (n + 1/2) × (1-a) times and (m + 1/2) × (1+a) times the center wavelength of the first laser light, n being a natural number. For example, the thickness of the first dimming sheet 1031 may be 15% thicker or 15% thinner than (m + 1/2) times the center wavelength of the second laser light; the thickness of the second dimming sheet 1032 may be 15% thicker or 15% thinner than (n + 1/2) times the center wavelength of the first laser light.

In another alternative implementation, the light modulation plate further comprises a light-transmitting carrier plate for carrying the half-wave plate, in addition to the half-wave plate, the half-wave plate is a light modulation film on the light-transmitting carrier plate, and the thickness of the light modulation film and the wavelength of light satisfy the above relationship. For example, the first dimming sheet 1031 includes a light-transmissive carrier sheet and a first dimming film, the thickness of the first dimming film is (m + 1/2) times of the central wavelength of the second laser, the second dimming sheet 1032 includes a light-transmissive carrier sheet and a second dimming film, the thickness of the second dimming film is (n + 1/2) times of the central wavelength of the first laser, and m and n are both natural numbers. Optionally, the thickness of the light-adjusting film may have a certain deviation from the multiple, for example, the deviation may be less than or equal to 15%. The thickness of the first light modulation film is between (m + 1/2) × (1-a) times and (m + 1/2) × (1+a) times of the central wavelength of the second laser, m is a natural number, and a =0.15; the thickness of the second light modulation film is between (n + 1/2) × (1-a) times and (m + 1/2) × (1+a) times of the central wavelength of the first laser, and n is a natural number. For example, the thickness of the first light modulation film may be 15% thicker or 15% thinner than (m + 1/2) times the center wavelength of the second laser light; the thickness of the second light modulation film may be 15% thicker or 15% thinner than (n + 1/2) times the central wavelength of the first laser light.

Alternatively, the first and

second dimming sheets

1031 and 1032 may also be rotated around the central axis, and the rotation angle may range from 0 to 15 degrees.

It should be noted that the first dimming sheet 1031 and the second dimming sheet 1032 may both adopt the same implementation manner of the two optional implementation manners, or may also respectively adopt the two optional implementation manners, and the embodiment of the present application is not limited.

Alternatively, the first laser light emitted by the laser 101 is red laser light, and the second laser light includes blue laser light and green laser light, the red laser light is P-polarized light, and the blue laser light and the green laser light are S-polarized light. Due to the depolarization problem, there may be a portion of the red laser light that is directed to the polarization splitting section 105 whose polarization state is closer to S-polarized light and a portion of the blue laser light and the green laser light whose polarization state is closer to P-polarized light. After passing through the polarization splitting unit 105, a part of the blue laser beam and a part of the green laser beam mixed with the red laser beam are emitted to the first light valve 1021, and a part of the red laser beam mixed with the blue laser beam and the green laser beam are emitted to the second light valve 1022. In the embodiment of the present application, the polarization direction of the first light adjusting plate 1031 is adjusted, so that the blue laser and the green laser mixed in the red laser still are P-polarized light when passing through the first light valve 1021 and the first light adjusting plate 1031 and being emitted back to the polarization splitting component 105, and then are emitted out of the lens 104 by the polarization splitting component 105, thereby playing a role in filtering the blue laser and the green laser mixed in the red laser. Similarly, the red laser light mixed into the blue laser light and the green laser light can be filtered by adjusting the polarization direction of the second light adjusting plate 1032.

In a possible case, there may be a certain error in the change of the polarization direction of the light by the light valve, so that the polarization direction of the target laser light cannot be accurately switched between the first polarization direction and the second polarization direction. The LCOS may have a certain pretilt angle, which results in that the adjustment angle of the LCOS to the polarization direction of the laser is not precise 90 degrees; for example, there may be a small included angle between the polarization direction of the first laser light emitted after passing through the first light valve 1021 and the second polarization direction. In this embodiment, the polarization direction compensation may be performed on the received laser light through the light adjusting sheet, so as to ensure that the polarization direction is changed to the second polarization direction when the first laser light emitted from the polarization splitting component 105 is re-emitted back to the polarization splitting component 105, and the polarization direction is changed to the first polarization direction when the second laser light is re-emitted back to the polarization splitting component 105. The light adjusting sheet in the embodiment of the present application may also be referred to as a wavelength compensation sheet.

In the embodiment of the present application, the working principle and the effect of the two light valves on the laser are the same, and the effect of the two light adjusting sheets on the laser is also the same, and only the first light valve 1021 and the first light adjusting sheet 1031 are taken as an example for description, and the related manners of the second light valve 1022 and the second light adjusting sheet 1032 can be compared. Illustratively, the first light valve 1021 is an LCOS, and the LCOS 1021 is used instead of the first light valve 1021. The first laser light emitted from the LCOS 1021 is not pure S-polarized light. The first light adjusting sheet 1031 can compensate the polarization direction of the first laser light emitted by the LCOS 1021 to a certain extent, so that the purity of the S-polarized light passing through the first light adjusting sheet 1031 is high, and the contrast of the first laser light can be further improved. Optionally, there may be some slight differences in the polarization angles of the first laser light emitted from different positions of the LCOS 1021, and the first dimming sheet 1031 may compensate for the most polarization angle of the emitted first laser light. For example, the first light adjusting sheet 1031 may rotate around its central axis within a certain angle range, and when the rotation angles of the first light adjusting sheet 1031 are different, the distances traveled by the first laser light in the first light adjusting sheet 1031 may be different, and further, the polarization direction of the first laser light may be adjusted.

Alternatively, the first dimming sheet 1031 may perform different processing for different wavelengths of light. The first light adjusting plate 1031 as in the first light valve 1021 may be used to perform polarization direction compensation on the received light of the first color (i.e. the light having the same color as the first laser light), and may not perform polarization direction compensation on the light of other colors than the first color.

It should be noted that, in a related art, red, green and blue lasers are sequentially modulated by a light valve, and the laser of each color is modulated, and a corresponding voltage is applied to the LCOS to deflect the liquid crystal therein to an angle corresponding to the laser of the color. When the wavelength difference of the laser is larger, the corresponding liquid crystal deflection angle is larger, and the deflection time consumption of the liquid crystal is longer. When the light valve is changed from modulating blue laser to modulating red laser, the liquid crystal needs to spend more time for changing the deflection angle in the process because the wavelength difference between the blue laser and the red laser is larger, so that the light emitting duration is shortened more, the laser modulation efficiency is poorer, and the display brightness of a projection picture is lower.

In the embodiment of the application, the red laser is modulated by one light valve, and the blue laser and the green laser are modulated by the other light valve, so that the modulation switching from the blue laser to the red laser can be avoided, and the time consumed by liquid crystal deflection is reduced. And since the wavelengths of the blue laser light and the green laser light are close to each other, even if the blue laser light modulation and the green laser light modulation are switched by the same light valve, the time taken for the liquid crystal deflection in the light valve is small. Moreover, the two light valves can work simultaneously, so that the laser modulation efficiency can be further improved, the light output quantity is improved, and the brightness of a projection picture is improved. For example, the laser 101 may emit the blue laser light and the green laser light in a time-sharing manner, and may emit the red laser light simultaneously when emitting the blue laser light and the green laser light.

In this embodiment, the first light valve 1021 and the second light valve 1022 respectively modulate two different laser beams, and each light valve can adjust the light emitting rate of the incident laser beam by adjusting the deflection angle of the liquid crystal therein. The absolute value of the difference between the reflectances of the two light valves to the incident laser light may be smaller than a probability threshold, for example, the probability threshold is 5% or 3%, and the embodiment of the present application is not limited. If the difference between the reflectivities is the difference between the reflectivity of the first light valve 1021 for the received laser light (e.g., the first laser light) and the reflectivity of the second light valve 1022 for the received laser light (e.g., the second laser light). Therefore, the reflectivity of the first laser light on the first light valve 1021 and the reflectivity of the second laser light on the second light valve 1022 can be kept substantially consistent, so that the problem that a projection picture formed after laser lights of various colors are modulated by the light valves possibly has uneven color matching due to the difference of the reflectivity of the laser lights of different polarization directions on the same light valve can be reduced, and the picture display effect of the projection equipment is improved.

In the embodiment of the present application, the laser 101 may emit red laser light, green laser light, and blue laser light. Fig. 4 is a schematic structural diagram of a laser provided in an embodiment of the present application, and fig. 4 illustrates an alternative arrangement of light emitting chips in the laser 101. As shown in fig. 4, the laser 101 includes two rows of light emitting chips 1011 attached to a base plate (not shown). Of the two rows of light emitting chips 1011, one row of light emitting chips 1011 is used to emit red laser light. The other row of light emitting chips 1011 includes: the light emitting diode comprises two first light emitting chip groups and a second light emitting chip group positioned between the two first light emitting chip groups, wherein light emitting chips 1011 in the first light emitting chip groups are used for emitting green laser, and light emitting chips 1011 in the second light emitting chip groups are used for emitting blue laser. The second row of light-emitting chips 1011 as seen from top to bottom in fig. 4 are all red light-emitting chips for emitting red laser light. The first light emitting chip group in the first row of light emitting chips 1011 includes two light emitting chips 1011 located at respective edges, such as the first two light emitting chips 1011 and the second two light emitting chips 1011 counted from left to right, and the four light emitting chips 1011 are used for emitting green laser. The second light emitting chip group includes three light emitting chips 1011 located at the middle region, and the three light emitting chips 1011 are used to emit blue laser light.

It should be noted that the arrangement position of each light emitting chip in the laser may be related to the heat dissipation performance of the light emitting chip itself. For example, the heat dissipation performance of the light emitting chip is related to the wavelength of the laser light emitted by the light emitting chip, and the light emitting chip emitting the laser light with a shorter wavelength may have better heat dissipation performance, so that the heat dissipation performance of the blue light emitting chip is better than that of the green light emitting chip. Because the middle area of the bottom plate has poor heat dissipation effect relative to the edge area, the light-emitting chips with good heat dissipation performance can be arranged close to the middle area of the bottom plate, for example, the blue light-emitting chips are arranged among the green light-emitting chips, so that the heat dissipation effect of the bottom plate is compensated to a certain extent through the heat dissipation performance of the light-emitting chips; therefore, the radiating effect of various light-emitting chips during working can be ensured to be more balanced, and the reliability of the laser is ensured to be higher.

Optionally, the laser 101 may also include a plurality of heat sinks 1012 and a plurality of reflecting prisms 1013. Each light emitting chip 1011 in the laser may correspond to one heat sink 1012 and one reflecting prism 1013. The heat sink 1012 may be fixed on the base plate, the light emitting chips 1011 are fixed on the heat sink 1012 to be fixed on the base plate, and the reflecting prisms 1013 are located at light emitting sides of the corresponding light emitting chips 1011. The light emitting chip 1011 can emit laser light to the corresponding reflection prism 103, and the reflection prism 1013 can emit the incident laser light in a direction away from the base plate, thereby realizing light emission of the laser 101.

Fig. 5 is a schematic structural diagram of another projection apparatus provided in an embodiment of the present application. As shown in fig. 5, the projection apparatus 10 in the embodiment of the present application may further include a light combining lens 108, where the light combining lens 108 may be located on the light emitting side of the laser 101. The laser light (including the first laser light) of the first color and the laser light (including the second laser light) of the second color emitted by the laser 101 may be emitted to the light combining lens 108, and the light combining lens 108 may mix the first laser light and the second laser light and emit the mixed laser light, so that the mixed laser light is emitted to the polarization beam splitting component 105. Illustratively, the light combining lens set 108 may include two light combining lenses. The first laser light and the second laser light may be respectively emitted to the two light combining lenses, and one light combining lens reflects the laser light (for example, the second laser light) emitted thereto to the other light combining lens, which may be a dichroic mirror. The other light combining lens can reflect the laser light (such as the first laser light) received from the laser 101 and transmit the laser light (such as the second laser light) received from the light combining lens, so that the first laser light and the second laser light are mixed and emitted.

Fig. 6 is a schematic structural diagram of a projection apparatus according to another embodiment of the present application, and fig. 7 is a schematic structural diagram of another projection apparatus according to another embodiment of the present application. As shown in fig. 6 and 7, in the above projection apparatus, as in fig. 5, the projection apparatus 10 may further include a beam scaling system 109, a light unifying part 110 and a focusing part 111 between the light combining mirror group 108 and the polarization splitting part 105. The light combining lens group 108 is configured to mix the first laser light and the second laser light and emit the mixed laser light to the light beam zooming system 109, the light beam zooming system 109 is configured to condense or expand the laser light emitted from the light combining lens group 108 and emit the expanded laser light to the light homogenizing part 110, the light homogenizing part 110 is configured to homogenize the laser light emitted from the light beam zooming system 109 and emit the homogenized laser light to the focusing part 111, and the focusing part 111 is configured to focus the laser light emitted from the light homogenizing part 110 to the polarization splitting part 105.

The beam scaling system 109 may include two lenses, which may include a convex lens and a concave lens. The distance between the two lenses is adjustable, the two lenses can expand the emitted laser at a certain distance, and the emitted laser can be contracted at another distance. As shown in fig. 6, the light unifying part 110 may include a fly-eye lens. Alternatively, as shown in FIG. 7, the light unifying member 110 may also include a light pipe. The focusing component 111 may include one convex lens, or may also include two convex lenses, and this embodiment of the application is illustrated by way of example that the focusing component 111 includes two convex lenses.

Alternatively, it is assumed that the first laser light emitted by the laser 101 in the projection apparatus of fig. 2 to 7 includes red laser light, and the red laser light is P-polarized light; the second laser includes blue laser light and green laser light, and the blue laser light and the green laser light are S polarized light. In this embodiment of the application, only the placement direction of the laser 101 may be adjusted, for example, the laser 101 in the projection apparatus of fig. 2 to 7 is rotated 90 degrees out of the paper or into the paper, so that the first laser includes red laser light, and the second laser includes blue laser light and green laser light. In this case, the arrangement of the light combining lens 108 on the light emitting side of the laser 101 needs to be adjusted accordingly.

To sum up, in the projection apparatus provided in the embodiment of the present application, the first laser and the second laser that are emitted by the laser device and have different colors and polarization directions may respectively pass through the light modulation sheet to emit to the light valves along different directions through the polarization beam splitting component, and the two light valves respectively modulate the two lasers and then emit back to the corresponding light modulation sheet so as to pass through the light modulation sheet to emit to the polarization beam splitting component. Each light valve can change the polarization direction of the incident laser and emit the laser, and the light adjusting sheet can adjust the polarization direction of the laser except the received target laser to counteract the change of the polarization direction of the light valve to the laser, wherein the target laser is the laser emitted to the light adjusting sheet from the first laser and the second laser. Therefore, the polarization directions of the first laser and the second laser which are emitted to the polarization light splitting component after passing through the light modulator and the light valve are changed, the first laser and the second laser can be transmitted in the direction different from the original transmission direction after being emitted to the polarization light splitting component, and then are emitted to the lens by the polarization light splitting component. The polarization direction of the laser except the first laser and the second laser after passing through the light modulator and the light valve is not changed, and the laser can return according to the original transmission direction after being shot to the polarization beam splitting component, so that the laser cannot be shot to the lens. Therefore, the laser mixed in the first laser and the second laser is prevented from being injected into the lens together with the first laser and the second laser, the filtering of other laser mixed in the first laser and the second laser is realized, the purity of the first laser and the second laser emitted by the lens can be improved, the proportion deviation of each color component in a projection picture is reduced, and the picture display effect of the projection equipment can be improved.

The term "at least one of a and B" in the present application is only one kind of association relationship describing an associated object, and means that three kinds of relationships may exist, for example, at least one of a and B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "at least one" refers to one or more, and the term "plurality" refers to two or more, unless expressly defined otherwise.

As used in this specification and the appended claims, certain terms are used to refer to particular components, and it will be appreciated by those skilled in the art that a manufacturer may refer to a component by different names. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, within which a person skilled in the art can solve the technical problem to substantially achieve the technical result.

The above description is only exemplary of the present application and should not be taken as limiting, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A projection device, characterized in that the projection device comprises: the device comprises a laser, a polarization beam splitting component, two dimming sheets, two light valves and a lens;

for the dimming sheet and light valve in either of the two directions: the light valve is used for emitting the received laser after the polarization direction is changed; the light adjusting sheet is used for adjusting the polarization direction of the received laser except for the target laser to offset the change of the polarization direction of the light valve to the laser except for the target laser, and the target laser is the laser which is emitted out of the polarization splitting component along any direction in the first laser and the second laser;

2. A projection apparatus according to claim 1 wherein said first laser light is polarized in a first polarization direction and said second laser light is polarized in a second polarization direction during the light emitted from said laser device to said polarization splitting means, said first polarization direction being perpendicular to said second polarization direction;

for the light adjusting sheet and the light valve in any direction, the light valve is used for rotating the polarization direction of the received laser light by 90 degrees so as to switch the polarization direction of the target laser light between the first polarization direction and the second polarization direction; the light adjusting sheet is used for rotating the polarization direction of the received laser except the target laser by 90 degrees.

3. The projection device of claim 2, wherein the two light modulators include a first light modulator and a second light modulator, and wherein the two light valves include a first light valve and a second light valve; the polarization beam splitting component is used for emitting the received first laser to the first light modulation sheet and emitting the received second laser to the second light modulation sheet; the first laser penetrates through the first dimming sheet and is emitted to the first light valve, and the second laser penetrates through the second dimming sheet and is emitted to the second light valve;

the first dimming sheet includes a half-wave plate for light of a color different from the first laser light, and the second dimming sheet includes a half-wave plate for light of a color different from the second laser light.

4. The projection device of claim 3, wherein the first light modulator tile comprises a half-wave plate for light of the same color as the second laser light and the second light modulator tile comprises a half-wave plate for light of the same color as the first laser light.

5. The projection device of claim 4, wherein the first light modulator has a thickness between (m + 1/2) × (1-a) times and (m + 1/2) × (1+a) times the center wavelength of the second laser light, m being a natural number, a =0.15; or the first dimming sheet comprises a light-transmitting bearing sheet and a first dimming film, and the thickness of the first dimming film is between (m + 1/2) × (1-a) times and (m + 1/2) × (1+a) times of the central wavelength of the second laser;

the thickness of the second dimming sheet is between (n + 1/2) × (1-a) times and (m + 1/2) × (1+a) times of the central wavelength of the first laser, and n is a natural number; or the second dimming sheet comprises a light-transmitting carrier sheet and a second dimming film, and the thickness of the second dimming film is between (n + 1/2) × (1-a) times and (m + 1/2) × (1+a) times of the central wavelength of the first laser.

6. The projection device of any of claims 2 to 5, wherein the light modulator sheet is further configured to rotate around the central axis by an angle in a range of 0 degrees to 15 degrees.

7. A projection apparatus according to any one of claims 1 to 5 wherein the polarization direction of said first laser light is a first polarization direction and the polarization direction of said second laser light is a second polarization direction in the process of being directed from said laser to said polarization splitting means;

for the light adjusting sheet in any direction, the light adjusting sheet is further used for carrying out polarization direction compensation on the received target laser;

after the polarization direction of the light valve is changed and the polarization direction of the light modulator is compensated, the polarization direction of the first laser is changed from the first polarization direction to the second polarization direction, and the polarization direction of the second laser is changed from the second polarization direction to the first polarization direction.

8. The projection device of claim 7, wherein for the light adjusting sheet in either direction, the light adjusting sheet is used for performing the polarization direction compensation on the received light with the same color as the target laser light.

9. The projection device of any of claims 1 to 5, wherein the projection device satisfies at least one of the following conditions:

the absolute value of the difference of the reflectivity of the two light valves to the incident laser is smaller than a probability threshold value;

the light valve comprises a Liquid Crystal On Silicon (LCOS);

and the first laser comprises red laser, and the second laser comprises at least one of blue laser and green laser; alternatively, the first laser includes at least one of blue laser and green laser, and the second laser includes red laser.

10. The projection apparatus of any of claims 1 to 5, wherein the projection apparatus further comprises a light combining mirror, a beam scaling system, a light unifying component, and a focusing component;

the first laser and the second laser irradiate to the light combining lens group, the light combining lens group is used for mixing the first laser and the second laser and irradiating the mixture to the light beam zooming system, the light beam zooming system is used for condensing or expanding the laser emitted by the light combining lens group and irradiating the laser to the light homogenizing component, the light homogenizing component is used for homogenizing the laser emitted by the light beam zooming system and irradiating the laser to the focusing component, and the focusing component is used for focusing the laser emitted by the light homogenizing component to the polarization light splitting component.