CN113960862A

CN113960862A - Projection device

Info

Publication number: CN113960862A
Application number: CN202010703587.8A
Authority: CN
Inventors: 李巍; 颜珂; 田有良
Original assignee: Qingdao Hisense Laser Display Co Ltd
Current assignee: Qingdao Hisense Laser Display Co Ltd
Priority date: 2020-07-21
Filing date: 2020-07-21
Publication date: 2022-01-21

Abstract

The application discloses projection equipment belongs to the photoelectric technology field. The projection equipment comprises a light source, a light valve, a lens, a first convex lens, a first diffusion sheet, a second convex lens and a light homogenizing part, wherein the first convex lens, the first diffusion sheet, the second convex lens and the light homogenizing part are positioned in a light path between the light source and the light valve; the focal points of the first convex lens and the second convex lens are superposed, and the superposed focal point is positioned between the first convex lens and the second convex lens; the first diffusion sheet is positioned at the focus; the first convex lens is used for converging light rays emitted by the light source to the first diffusion sheet, the first diffusion sheet is used for emitting the incident light rays to the second convex lens after expanding the divergence angle of the incident light rays, the second convex lens is used for emitting the incident light rays to the light homogenizing part, the light homogenizing part is used for homogenizing the incident light rays and then emitting the homogenized light rays to the light valve, and the light spot area on the first convex lens is larger than that on the second convex lens. The application solves the problem that the display effect of the projection picture of the projection equipment is poor. The application is used for projection.

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 requirement for the display effect of the projection picture of the projection device is higher and higher.

Fig. 1 is a schematic structural diagram of a projection apparatus provided in the related art. As shown in fig. 1, the projection apparatus 00 includes: light source 001, light guide tube 0021, lighting mirror group 0022, light valve 0024, lens 003. The light pipe 0021 is in the shape of a strip, and the light inlet D1 and the light outlet D2 of the light pipe 0021 are located at two ends of the light pipe in the length direction (e.g., x direction in fig. 1). The light source 001 emits light into the light inlet D1 of the light pipe 0021, the light pipe 0021 homogenizes the light transmitted therein, and the light is emitted from the light outlet D2 of the light pipe 0021 to the illumination mirror group 0022. The illuminating mirror group 0022 can adjust the transmission direction of the incident light and then emit the light to the light valve 0024, the light valve 0024 can modulate the incident light so as to emit the light required for imaging in the incident light to the lens 003, and then the lens 003 projects the light to form a projection picture.

In the above-mentioned structure of the projection device, on one hand, in order to pursue better uniformity of the light spots and further ensure better uniformity of the projection image, it is desirable that the light-equalizing effect of the light guide is good, and the light-equalizing effect of the light guide is substantially proportional to the length of the light guide, so the length of the light-equalizing optical path using the light guide is usually longer, which is not favorable for miniaturization of the light path structure. The light inlet of the light guide tube has a limited light inlet angle range, and light beams beyond the angle range can be regarded as stray light which cannot enter the light guide tube and further cannot be utilized by the rear-end light valve, so that the optical utilization rate is low.

Moreover, when a laser light source is used, especially when emitting multi-color laser, in order to ensure the quality of the projected picture, it is necessary to provide a speckle-dispersing component in the light path, such as a rotating diffusion sheet in the light path before the light-entering port of the light guide, to improve the coherence of the laser beam, but this will further increase the length and volume of the light path. Adding a new speckle reduction component to an existing optical circuit structure usually results in a change in the arrangement of the optical circuit, and the optical circuit structure becomes large and complex.

Disclosure of Invention

The application provides a projection device, which can solve the problems that the display effect of a projection picture of the projection device is poor and the volume of the projection device is large. The projection apparatus includes: the light source is used for emitting light to the light valve, the light valve is used for modulating the incident light and then irradiating the modulated light to the lens, and the lens is used for projecting the incident light;

the projection device further includes: the first convex lens, the first diffusion sheet, the second convex lens and the light homogenizing part are positioned in a light path between the light source and the light valve; the focal points of the first convex lens and the second convex lens are superposed, and the superposed focal point is positioned between the first convex lens and the second convex lens; the first diffusion sheet is positioned at the focus;

the first convex lens is used for converging light rays emitted by the light source to the first diffusion sheet, the first diffusion sheet is used for expanding the divergence angle of the incident light rays and then irradiating the light rays to the second convex lens, the second convex lens is used for irradiating the incident light rays to the light homogenizing part, the light homogenizing part is used for homogenizing the incident light rays and then irradiating the light rays to the light valve, and the light spot area on the first convex lens is larger than that on the second convex lens.

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

in the projection equipment that this application provided, first convex lens, first diffusion piece, second convex lens and even light part have arranged in proper order in the light-emitting direction of light source. The focus coincidence of first convex lens and second convex lens, and the facula area on the first convex lens is greater than the facula area on the second convex lens, and first convex lens and second convex lens can carry out the beam contracting to the light that the light source sent, guarantee that light shines more even light part in order to be used for forming the projection picture, guarantee that the utilization ratio of light is higher. And because the first diffusion sheet is positioned at the coincident focus, on one hand, according to the principle of light beam convergence imaging, light rays at the focus (the convergence imaging position) can emit to the lens at any light beam angle emitted by the point light source and can be collimated into parallel light beams by the lens, therefore, the first diffusion sheet can be set to be at a larger divergence angle to diffuse the incident laser light beams to a larger degree, so that the homogenization effect of the laser light beams is good, and the laser light beams after being diffused by the large angle can still be converged into a collimation state by the second convex lens after being shot to the second convex lens.

On the other hand, the size of the light spot of the laser beam collimated by the second convex lens is reduced, the beam shrinking of the laser beam is realized, and the utilization of the rear optical lens is facilitated. In the technical scheme, a special light path position is not additionally arranged for the first diffusion sheet, but the first diffusion sheet is positioned between the two original lenses, so that the dual functions of beam shrinkage and spot dissipation can be achieved, and the length of a light path cannot be increased.

Therefore, the projection equipment can enlarge the divergence angle of the light emitted by the light source to reduce the coherence of the light without influencing the light beam contraction and ensuring that the light utilization rate and the light path length are not increased, thereby weakening the speckle effect of the projection equipment and improving the display effect of the projection picture of the projection equipment.

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 partial structural diagram of a projection apparatus 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 another projection apparatus provided in an 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 electro-optical technology, the demand for miniaturization of projection devices is increasing. Fig. 1 is a schematic structural diagram of a projection apparatus provided in the related art. As shown in fig. 1, the projection apparatus 00 may include: a light source 001, an optical engine (not shown in fig. 1), and a lens 003. The light source 001 may include a laser 0011, a light combining lens 0012 and a converging lens 0013. This laser 0011 can send light (for example red green blue three-colour laser) to the light combination mirror group 0012, and this light combination mirror group 0012 can mix the light that this laser 0011 sent, and the light directive that will mix is convergent lens 0013, and convergent lens 0013 converges the light that shines into and the directive ray machine. The light engine may include: a diffusion sheet 0020, a light pipe 0021, an illuminating mirror group 0023 and a light valve 0024. The light pipe 0021 is in the shape of a strip, and the light inlet D1 and the light outlet D2 of the light pipe 0021 are located at two ends of the light pipe in the length direction (e.g., x direction in fig. 1). The light source 001 emits light to the diffusion sheet 0020, the light is diffused on the diffusion sheet 0020 and then enters the light inlet D1 of the light guide 0021, the light guide 0021 homogenizes the light transmitted therein, and the light is emitted from the light outlet D2 of the light guide 0021 to the illumination lens group 0023. The illumination lens assembly 0023 includes a light collecting lens assembly composed of two lenses, a reflector F, a lens T4, and a total internal reflection prism L. As shown in fig. 1, the light collecting lens group includes a lens T1 and a lens T2. The light can first enter the lens T1, be diffused in the lens T1 and collimated when exiting the lens T1 and then emitted to the lens T2, the lens T2 can further collimate the emitted light and then emit to the reflector F, which reflects the light to the lens T4, and then the lens T4 converges the light to the tir prism L. The tir prism L may adjust the direction of travel of the light to direct the light to the light valve 0024. The light valve 0024 includes a plurality of pixels, and the light valve 0024 may make the pixels to be displayed in a bright state emit the incident light to the lens according to the image to be displayed, so as to modulate the light. The lens 003 is located at a side of the tir prism L far away from the light valve 0024, and the lens 003 may include a plurality of lenses (not shown in fig. 1), and for the arrangement of the structures in the optical engine 00 shown in fig. 1, the lenses in the lens 003 should be arranged in sequence in a direction perpendicular to the paper surface. The light emitted from the light valve 0024 can sequentially pass through a plurality of lenses in the lens 003 to be reflected to the screen, so that the lens 003 can project the light, and the display of a projection picture is realized.

It should be noted that a speckle effect is usually generated when a laser is used as a light source of a projection device for projection display. The speckle effect refers to an effect that after two laser beams emitted by a coherent light source are scattered when irradiating a rough object (such as a screen of a projection device), the two laser beams interfere in space, and finally granular light and dark spots appear on the screen. Two adjacent light emitting chips emitting laser with the same wavelength and constant phase in the laser are coherent light sources. The speckle effect makes the display effect of the projection image worse, and the spots which are not focused and have alternate light and shade are in a twinkling state when being seen by human eyes, so that the user is easy to feel dizzy when watching for a long time, and the watching experience of the user is worse. The diffuser 0020 in the optical engine can diffuse the light emitted from the light source 001 to reduce the coherence of the light. However, the light diffused by the diffusion sheet 0020 has a large diffusion angle, so that more light cannot enter the light guide tube, the utilization rate of the light is low, and further, the brightness angle of the projection image of the projection equipment and the display effect of the projection image are poor.

In addition, since the light guide tube is used as a light-homogenizing part in the optical engine in the related art, and the length of the light guide tube is positively correlated with the light-homogenizing effect of the light guide tube, the length of the light guide tube needs to be designed to be longer so as to ensure that the uniformity of the light emitted by the optical engine is higher. Therefore, the light guide tube needs to occupy more space, the size of the optical machine is larger, and the miniaturization of the projection equipment is difficult to realize.

The following embodiments of the present application provide a projection apparatus, and a display effect of a projection picture of the projection apparatus may be better. In addition, the projection device can be miniaturized easily.

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 00 includes: the light source 20 is used for emitting light to the light valve 103, the light valve 103 is used for modulating the incident light and then emitting the modulated light to the lens 30, and the lens 30 is used for projecting the incident light.

Projection device 00 further comprises: a first convex lens 1041, a first diffusion sheet 105, a second convex lens 1042, and a light uniformalizing member 101, which are positioned in the optical path between the light source 20 and the light valve 103. For example, the first convex lens 1041, the first diffusion sheet 105, the second convex lens 1042 and the light uniformizing part 101 may be sequentially arranged along a light outgoing direction (e.g., x direction in fig. 2) of the light source 20. The focal points of the first convex lens 1041 and the second convex lens 1042 are overlapped, and the overlapped focal point is located between the first convex lens 1041 and the second convex lens 1042. The first diffuser 105 is located at the focal point. Alternatively, the optical axes of the first convex lens 1041 and the second convex lens 1042 may be collinear.

The first convex lens 1041 can converge the light emitted from the light source 20 to a focal point thereof, so that the first convex lens 1041 can converge the light emitted from the light source 20 to the first diffusion sheet 105, the first diffusion sheet 105 is configured to expand a divergence angle of the incident light and emit the expanded light to the second convex lens 1042, the second convex lens 1042 is configured to emit the incident light to the light homogenizing member 101, and the light homogenizing member 101 is configured to homogenize the incident light and emit the homogenized light to the pipe valve 103. The first convex lens 1041 and the second convex lens 1042 may form a beam shrinking component to shrink the beam of light entering the first convex lens, so the light spot area on the first convex lens 1041 is larger than the light spot area on the second convex lens 1042. That is, the area of the light spot formed by the light emitted from the light source on the first convex lens 1041 is larger than the area of the light spot formed by the light emitted from the first diffusion sheet 105 on the second convex lens 1042.

In this embodiment, the light source 20 and the lens 30 may refer to descriptions of the light source 001 and the lens 003 in fig. 1, and the light valve 103 may refer to a description related to the light valve 0024 in fig. 1, which is not described again in this embodiment.

Alternatively, the light rays emitted from the light source to the first convex lens 1041 may be parallel to the optical axis of the first convex lens 1041, or substantially parallel to the optical axis (i.e. the included angle between the light rays and the optical axis is smaller than a certain angle threshold). The convex lens can converge the light parallel to the optical axis at the focal point, and the convex lens can change the light entering from the focal point into the light parallel to the optical axis. Therefore, the light emitted from the light source can be converged at the focal point after passing through the first convex lens 1041, and the light can be emitted to the second convex lens 1042 again and becomes parallel light through the second convex lens 1042. In this case, the light source 20 may not include a converging lens, or the converging lens may be replaced by a collimating lens to ensure that the light emitted from the light source to the light engine is parallel or approximately parallel.

In this embodiment, since the light rays are converged at the focus and then continuously transmitted to the second convex lens 1042, the light spot area on the first convex lens 1041 is larger than the light spot area on the second convex lens 1042. That is, the lens group consisting of the first convex lens 1041 and the second convex lens 1042 can narrow the input light beam, ensure that more light rays are emitted to the dodging component to form a projection picture, and ensure that the utilization rate of the light rays is higher.

In the embodiment of the application, the first diffusion sheet is positioned at the focus of the second convex lens, so that even if the diffusion angle of the first diffusion sheet is larger, the light emitted from the first diffusion sheet can be ensured to emit to the second convex lens in a larger diffusion angle range, and can still be collimated to be emitted approximately in parallel. Therefore, the projection equipment can enlarge the divergence angle of the light emitted by the light source to reduce the coherence of the light on the basis of ensuring the light utilization rate without influencing the light beam contraction, further weaken the speckle effect of the projection equipment and improve the display effect of the projection picture of the projection equipment. And because the loss of the light rays emitted to the dodging component is less, the high optical collection efficiency of the dodging component to the light rays can be ensured. The larger the diffusion angle of the diffusion sheet, the smaller the coherence of the light passing through the diffusion sheet. In the embodiment of the application, the first diffusion sheet is located at the focus of the first convex lens and the focus of the second convex lens, and even if the diffusion angle of the first diffusion sheet is large, the beam shrinkage of the first convex lens and the second convex lens on light rays cannot be influenced, so that the diffusion angle of the first diffusion sheet can be large, the homogenization degree of the diffusion sheet on laser beams is high, and the elimination effect on the speckle effect is good.

In the embodiment of the application, the first diffusion sheet is arranged between the first convex lens and the second convex lens, so that the position for arranging the first diffusion sheet is not required to be independently arranged, and the arrangement of components in the optical machine is compact, so that the speckle effect can be weakened while the volume of the optical machine is ensured to be small.

In summary, in the projection apparatus provided in the embodiment of the present application, the first convex lens, the first diffusion sheet, the second convex lens, and the light uniformizing member are sequentially arranged on the light path between the light source and the light valve. The focus of first convex lens and the coincidence of the focus of second convex lens, and the facula area on the first convex lens is greater than the facula area on the second convex lens, and first convex lens and second convex lens constitute beam contracting system, can carry out beam contracting to the light that the light source sent, guarantee that light shoots even light part more in order to be used for forming the projection picture, guarantee that the utilization ratio of light is higher. And because the first diffusion sheet is positioned at the coincident focus, on one hand, according to the principle of light beam convergence imaging, light rays at the focus (the convergence imaging position) can emit to the lens at any light beam angle emitted by the point light source and can be collimated into parallel light beams by the lens, therefore, the first diffusion sheet can be set to be at a larger divergence angle and can diffuse the incident laser light beams to a larger degree, so that the homogenization effect of the laser light beams is good, and the laser light beams after being diffused by the large angle can still be collimated into the parallel light beams or approximately parallel light beams by the second convex lens after being shot to the second convex lens.

In an alternative implementation manner, in the embodiment of the present application, the focal length of the first convex lens 1041 is greater than the focal length of the second convex lens 1042. Therefore, the distance between the first convex lens 1041 and the coincident focal point of the first diffusion sheet 105 is greater than the distance between the second convex lens 1042 and the coincident focal point, the optical path of the light from the coincident focal point to the second convex lens 1042 is short, the divergence angle of the light when the light is emitted to the second convex lens is small, and the light spot formed by the light on the second convex lens 1042 is small. This ensures that the light spot area on the first convex lens 1041 is larger than the light spot area on the second convex lens 1042.

Optionally, the ratio of the area of the light spot on the first convex lens 1041 to the area of the light spot on the second convex lens 1042 may be in a range of 1.5 to 3. That is, the beam-shrinking magnification range of the beam-shrinking component composed of the first convex lens 1041 and the second convex lens 1042 is 1.5-3 times. Alternatively, the beam-reducing magnification of the beam-reducing component for the light can be designed correspondingly according to the specific structure of the light source 20. If the light source 20 includes two lasers, the beam-shrinking magnification range of the beam-shrinking component to the light can be 1.5-2 times; if the light source comprises three lasers, the beam-shrinking magnification range of the beam-shrinking component to the light rays can be 2-3 times.

Optionally, an area of an orthographic projection of the first convex lens 1041 on a plane perpendicular to an optical axis thereof is larger than an area of an orthographic projection of the second convex lens 1042 on the plane, that is, a size of the first convex lens 1041 is larger than a size of the second convex lens 1042, and an aperture of the first convex lens 1041 is larger than an aperture of the second convex lens 1042. The light spot formed by the light on the second convex lens 1042 can be smaller than the light spot formed by the light on the first convex lens 1041, so the size of the first convex lens 1041 can be larger than the size of the second convex lens 1042, and the waste of the convex lens caused by the arrangement of the larger second convex lens 1042 is avoided.

Alternatively, the center of the first diffusion sheet 105 may coincide with the focal points of the first convex lens 1041 and the second convex lens 1042. The first diffusion sheet 105 may be perpendicular to the arrangement direction (i.e., x direction in fig. 2) of the first convex lens 1041 and the second convex lens 1042, that is, the first diffusion sheet 105 is located at a focal plane where the first convex lens 1041 and the second convex lens 1042 coincide. Alternatively, the diffusion angle of the first diffusion sheet 105 ranges from 8 degrees to 16 degrees.

The first diffusion sheet 105 may have a plate-shaped structure, and the first diffusion sheet 105 may include two larger surfaces, which are parallel, and a plurality of smaller sides connecting the two larger surfaces. The first diffuser 105 is perpendicular to the x-direction, i.e., the two larger surfaces of the first diffuser 105 are perpendicular to the x-direction. Since the thickness of the first diffuser 105 is very thin, which is the distance between the two larger surfaces, it can also be directly considered as the first diffuser 105 perpendicular to the x-direction.

The light source 20 of the embodiment of the present application may emit laser light of at least two colors. When the light emitted by the light source is laser, the projection equipment can generate a speckle effect, so that the speckle effect is reduced by arranging a diffusion sheet. Optionally, the at least two colors of laser light may include: the laser light of a first divergence angle and the laser light of a second divergence angle, the first divergence angle is greater than the second divergence angle. Illustratively, the at least two colors of laser light may include: the red laser is laser with a first divergence angle, and the green laser and the blue laser are laser with a second divergence angle.

Based on the light source 20, the first diffusion sheet 105 in the embodiment of the present application may include a first diffusion region and a second diffusion region, and the diffusion angle of the first diffusion region is smaller than that of the second diffusion region. The laser light of the first divergence angle may be directed to the first diffusion region, and the laser light of the second divergence angle may be directed to the second diffusion region. The divergence angle of the laser emitted to the first diffusion region is larger than that of the laser emitted to the second diffusion region, and the divergence angle of the first diffusion region is smaller than that of the second diffusion region. Therefore, the angle difference of the laser with different colors and different divergence angles emitted from the first diffusion sheet after divergence can be smaller, the uniformity of the laser for projection is ensured, and the display effect of a projection picture is further improved.

Alternatively, the first diffusion sheet 105 may be a moving diffusion sheet. The light source 20 may sequentially emit light of at least two colors according to a time sequence with which the first diffusion sheet 105 is moved. The moving mode (such as moving speed and moving direction) of the first diffusion sheet can be adjusted appropriately to ensure that when the light source 20 emits the laser light with the first divergence angle, the first diffusion area in the first diffusion sheet 105 is located in the irradiation area of the laser light; and when the light source 20 emits the laser light of the second divergence angle, the second diffusion area in the first diffusion sheet 105 is located in the irradiation area of the laser light.

In the embodiment of the present application, the light unifying part 101 may include a fly-eye lens. The fly-eye lens has a good light homogenizing effect, and the light homogenizing effect of the fly-eye lens is irrelevant to the thickness of the fly-eye lens, so that the good light homogenizing effect can be ensured by adopting the thin fly-eye lens, and the miniaturization of the projection equipment is further ensured.

Alternatively, the fly-eye lens has a good effect of homogenizing parallel light, and the light rays emitted to the fly-eye lens can be parallel light or approximately parallel light. Alternatively, the optical axes of the first convex lens 1041, the second convex lens 1042, and the fly-eye lens may be collinear. It should be noted that, in the embodiments of the present application, the beam reduction component is disposed between the light source and the fly-eye lens to reduce the light spot emitted to the fly-eye lens, so that the size of the fly-eye lens can be smaller. The cost of the fly-eye lens is high, so that the cost of the fly-eye lens can be saved, and the manufacturing cost of the projection equipment can be further saved.

With continued reference to fig. 2, the fly-eye lens may include a plurality of lens units Y. Such as the plurality of lens units Y may be arranged in an array. The fly-eye lens may satisfy at least one of:

the forward projection area range of the fly-eye lens on a plane vertical to the optical axis of the fly-eye lens is 144-265 square millimeters;

the orthographic projection of the fly-eye lens on a plane perpendicular to the optical axis of the fly-eye lens is rectangular, and the length-width ratio range of the rectangle is 1.6-2;

the maximum distance range of both ends of the lens unit Y in the direction perpendicular to the optical axis is 0.5 mm to 1.5 mm;

and the light transmittance of the fly-eye lens ranges from 98% to 99%.

Fig. 2 shows only six lens units Y in the fly-eye lens. Alternatively, the number of the lens units Y in the fly-eye lens may be set according to the shape and size of the lens units Y, and the size of the fly-eye lens. For example, the number of the lens units Y in the fly-eye lens may be 10, 20, 50 or more, and the embodiment of the present application is not limited thereto.

For example, the orthographic projection of the fly-eye lens on a plane perpendicular to the optical axis of the fly-eye lens (i.e. a plane perpendicular to the x direction) may be a quadrangle, and if the quadrangle is a square, the side length of the square may be in a range of 12 mm to 25 mm. Optionally, the orthographic projection of the fly-eye lens on the plane may also be in other shapes, such as a rectangle, a circle, an ellipse, or the like, and the embodiment of the present application is not limited.

As another example, the orthographic projection of the lens unit Y on a plane perpendicular to the optical axis of the fly-eye lens may be circular, elliptical, quadrangular, hexagonal, or other shape. If the orthographic projection of the lens unit Y going upward on the plane is circular, the distances between the two ends of the lens unit Y in the direction perpendicular to the optical axis are both the diameter of the circle. If the orthographic projection of the lens unit Y on the plane is an ellipse, the maximum distance between the two ends of the lens unit Y in the direction perpendicular to the optical axis is the major axis of the ellipse. If the orthographic projection of the lens unit Y on the plane is rectangular, the maximum distance between the two ends of the lens unit Y in the direction perpendicular to the optical axis is the length of the rectangle. If the orthographic projection of the lens unit Y on the plane is hexagonal, the maximum distance between two ends of the lens unit Y in the direction perpendicular to the optical axis is the length of the longest diagonal line of the rectangle.

Because the light spot on the fly-eye lens and the light spot on the light valve 103 are in an object-image relationship, and the length-width ratio of the light spot on the fly-eye lens is the same as the length-width ratio of the light spot at the light valve 103, the fly-eye lens can be designed according to the light valve 103. For example, the fly-eye lens is designed to have the same length-width ratio of the orthographic projection on the plane perpendicular to the optical axis as that of the light valve 103, for example, the length-width ratio is in the range of 1.6-2.

In the related art, the light guide tube is used as a light uniformizing part, so that the loss of light in the transmission process of the light guide tube is high, and the light transmittance of the light guide tube is low. The light pipe is strip-shaped, the size of the light inlet of the light pipe is small, and the light incident angle of the light pipe is small. For example, the center of the light entrance of the light guide tube may be located on the optical axis of the converging lens, and when the included angle between the light emitted from the converging lens and the optical axis of the converging lens is within the light entrance angle range of the light guide tube, the light may enter the light guide tube. Generally, the incident angle of the light guide is smaller than 23 degrees, and the light emitted from the converging lens has more light included angles with the optical axis larger than 23 degrees, which are wasted, so that more light emitted from the light source is wasted, and the utilization rate of the light emitted from the light source is low.

In the embodiment of the application, the light transmittance of the fly-eye lens can reach 98% -99%, and the light transmittance of the fly-eye lens is greater than that of the light guide pipe, so that the loss of light in the light homogenizing process can be reduced. The size of the fly-eye lens can be larger than that of the light inlet of the light guide pipe, light emitted by the light source can be emitted to the fly-eye lens more, and then the light is emitted after being homogenized by the fly-eye lens, so that the utilization rate of the light emitted by the light source is high, the light loss is less, and the light efficiency of the optical machine is higher.

Fig. 3 is a schematic structural diagram of another projection apparatus provided in an embodiment of the present application. As shown in fig. 3, the projection apparatus 00 may further include: and a second diffusion sheet 106, wherein the second diffusion sheet 106 is positioned between the second convex lens 1042 and the light homogenizing member 101. Alternatively, the diffusion angle of the second diffusion sheet 106 may be smaller than that of the first diffusion sheet 105. For example, the diffusion angle of the second diffusion sheet 106 ranges from 1 degree to 6 degrees. Alternatively, the second diffusion sheet 106 may be fixedly disposed. Optionally, the second diffusion plate 106 may also be located in the optical path before the light emitted from the light source 20 enters the first convex lens 1041, for example, the second diffusion plate 106 may also be located between the light source 20 and the first convex lens 1041, which is not illustrated in this embodiment of the application.

In the embodiment of the application, on the basis of the first diffusion sheet 105, the second diffusion sheet 106 may be further disposed to further assist the first diffusion sheet 105 to diffuse and homogenize light, so as to further reduce the speckle effect of the projection apparatus. In addition, since the second diffusion sheet 106 is close to the light uniformizing member 101, and the light passing through the second diffusion sheet 106 is transmitted according to the exit angle thereof, the diffusion angle of the second diffusion sheet 106 is made smaller, thereby preventing the light passing through the second diffusion sheet 106 from being emitted to the outside of the light uniformizing member 101 due to the larger diffusion angle, which causes light waste. In addition, because the lens group 104 narrows the light, the light spot emitted to the second diffusion sheet 106 is small, and the area of the second diffusion sheet 106 can also be small, thereby further reducing the manufacturing cost of the optical machine.

Optionally, with continued reference to fig. 3, the projection device 00 may further include: the first drive structure 107, and/or the second drive structure 108. Fig. 3 illustrates an example in which the projection device comprises both the first driving structure 107 and the second driving structure 108. The first driving structure 107 is used for driving the diffusion sheets (such as the first diffusion sheet 105 and the second diffusion sheet 106) between the light source and the light uniformizing part 101 to move along a target direction, wherein the target direction intersects with the arrangement direction (i.e. the x direction) of the light source and the light uniformizing part 101. For example, the target direction is perpendicular to the x-direction, such as the y-direction, or the target direction is perpendicular to both the x-direction and the y-direction (i.e., perpendicular to the plane of the paper). The second driving structure 108 is used for driving the diffusion sheet to rotate around the axial direction parallel to the arrangement direction (i.e. the x direction) of the light sources and the light uniformizing part 101.

The diffusion sheet includes microstructures with different diffusion angles arranged according to a certain rule, for example, the microstructures may be similar to micro convex lenses. The diffusion piece can guarantee that light shines to the different positions of diffusion piece at different moments when moving, and the angle of divergence of light at different moments is different like this, and projection equipment carries out the speckle of the different shape positions that the projection formed according to this light and can scatter the stack, and then the user can't see obvious speckle, has played the effect of better elimination speckle.

It should be noted that, only one of the first diffusion plate 105 and the second diffusion plate 106 may be driven by the at least one driving structure to move, or both of the two diffusion plates may be driven by the at least one driving structure to move, and the moving manners of the two diffusion plates may be the same or different, and the embodiment of the present invention is not limited thereto. For example, fig. 3 illustrates the first diffusion plate 105 moving under the driving of the first driving structure 107, and the second diffusion plate 106 moving under the driving of the second driving structure 108.

Optionally, with continuing reference to fig. 2 and 3, the projection device 00 may further include: an illumination mirror group 102 is disposed between the light uniformizing section 101 and the light valve 103. The illumination lens assembly 102 may include: a third convex lens T3, a reflective sheet F, a fourth convex lens T4, and a total internal reflection prism L. The light emitted from the light unifying unit 101 may be emitted to the reflective sheet F through the third convex lens T3, the reflective sheet F may reflect the emitted light to the fourth convex lens T4, the fourth convex lens T4 may converge the emitted light to the tir prism L, and the tir prism L reflects the emitted light to the light valve 103. It should be noted that, for the description of the illumination mirror group 102, reference may be made to the related description of the illumination mirror group 0023 in fig. 1.

It should be noted that the light emitted from the light guide tube in the related art needs to pass through at least two lenses to be emitted to the reflective sheet. In the embodiment of the present application, the beam shrinking component formed by the first convex lens and the second convex lens can emit parallel light, and the collimation of the light emitted by the fly eye lens is high, so that the light meeting the modulation requirement of the light valve can be obtained only by reducing the divergence angle of the light through one light receiving convex lens (i.e., the third convex lens), and then the light is sequentially emitted to the reflector plate, the fourth convex lens and the light valve. Because the number of the light receiving lenses between the light homogenizing component and the reflector plate is reduced in the embodiment of the application, the volume of the projection equipment can be further ensured to be smaller, and the miniaturization of the projection equipment is facilitated.

Fig. 4 is a schematic partial structural diagram of a projection apparatus provided in an embodiment of the present application, and only a partial structure of an illumination mirror group and a light valve are illustrated. The illumination mirror group 102 and the light valve 103 shown in fig. 4 may be a left view of the illumination mirror group 102 and the light valve 103 shown in fig. 2 or fig. 3, and the illumination mirror group 102 and the light valve 103 shown in fig. 2 or fig. 3 may be a view rotated 90 degrees clockwise from a top view of the illumination mirror group 102 and the light valve 103 shown in fig. 4. As shown in fig. 4, the tir prism L in the illumination mirror group 102 may include two triangular prisms (a first prism L1 and a second prism L2), and the second prism L2 may be located on a side of the first prism L1 away from the light valve 103. An air gap can exist between two surfaces which are close to each other in the first prism L1 and the second prism L2, and then the two prisms can form a total internal reflection prism, so that the light rays entering the first prism L1 can be totally reflected on the side surface which is close to the second prism L2, and then the light rays exit the first prism L1 and shoot to the light valve 103. The light valve 103 can reflect the light beam, so that the light beam sequentially passes through the first prism L1 and the second prism L2 to be emitted to the lens. Alternatively, the light path of the light in the illumination mirror group 102 may also be referred to as an illumination light path.

Optionally, the light valve in the embodiment of the present application may be modified adaptively according to the projection architecture of the projection apparatus. Illustratively, the light valve may be a Liquid Crystal On Silicon (LCOS), a Liquid Crystal Display (LCD), or a Digital Micromirror Device (DMD). The embodiment of the present application takes a projection device adopting a Digital Light Processing (DLP) architecture, and the Light valve is a DMD as an example for explanation. Illustratively, the DMD includes a plurality of tiny reflective sheets (not shown), each of which can be regarded as a pixel, and the light reflected by each of the reflective sheets can be used to display a pixel point in a projected picture. The reflector plate can be in two states, the reflector plate can reflect the incident light to the lens in the first state, and the reflector plate can reflect the incident light to the outside of the lens in the second state, so that bright and dark display of the pixels is realized. For example, the reflective sheet may be in the first state when rotated by plus 17 degrees or plus 12 degrees from the initial state, and the reflective sheet may be in the second state when rotated by minus 17 degrees or minus 12 degrees from the initial state. For example, if the light valve shown in fig. 3 represents a reflective sheet, the reflective sheet may be in the first state at this time, and the initial state of the reflective sheet may be a state in which the reflective sheet is parallel to the side of the first prism L1 adjacent thereto. If the angle of clockwise rotation of the reflection sheet from the initial state is positive, the angle of counterclockwise rotation from the initial state is negative. Therefore, the projection equipment can project a corresponding projection picture by adjusting the state of each reflecting sheet in the DMD.

In summary, in the projection apparatus provided in the embodiment of the present application, the first convex lens, the first diffusion sheet, the second convex lens, and the light uniformizing member are sequentially arranged on the light path between the light source and the light valve. The focus coincidence of first convex lens and second convex lens, and the facula area on the first convex lens is greater than the facula area on the second convex lens, and first convex lens and second convex lens can constitute beam contracting system and carry out the beam contracting to the light that the light source sent, guarantee that light shines more even light part in order to be used for forming the projection picture, guarantee that the utilization ratio of light is higher. And because the first diffusion sheet is positioned at the coincident focus, on one hand, according to the principle of light beam convergence imaging, light rays at the focus (the convergence imaging position) can emit to the lens at any light beam angle emitted by the point light source and can be collimated into parallel light beams by the lens, therefore, the first diffusion sheet can be set to be at a larger divergence angle to diffuse the incident laser light beams to a larger degree, so that the homogenization effect of the laser light beams is good, and the laser light beams after being diffused by the large angle can still be converged into a collimation state by the second convex lens after being shot to the second convex lens.

The foregoing embodiments of the present application are illustrated in the case of a projection apparatus including a beam reduction member composed of a first convex lens 1041 and a second convex lens 1042, a first diffusion sheet 105, and a second diffusion sheet 106. In an alternative implementation manner of the projection device, the projection device may also include only any one or any two of the three structures, and the embodiment of the present application is not limited. For example, the projection apparatus may include the beam-reducing member without including the first diffusion sheet 105 and the second diffusion sheet 106; alternatively, the projection apparatus may include the beam-reducing member and the first diffusion sheet 105 without the second diffusion sheet 106; alternatively, the projection apparatus may include the beam-reducing member and the second diffusion sheet 106 instead of the first diffusion sheet 105; alternatively, the projection apparatus may include the second diffusion sheet 106 instead of the beam reduction member and the first diffusion sheet 105.

Fig. 5 is a schematic structural diagram of another projection apparatus provided in an embodiment of the present application. As shown in fig. 5, a lens assembly composed of a convex lens 1043 and a concave lens 1044 may be adopted to replace the structure composed of the first convex lens 1041, the second convex lens 1042 and the first diffusion plate 105 in fig. 2 or fig. 3, so as to obtain an alternative structure of the projection apparatus. The convex lens 1043 and the concave lens 1044 are arranged along the arrangement direction (x direction in fig. 5) of the light source 20 and the light uniforming member 101. The lens assembly composed of the convex lens 1043 and the concave lens 1044 is a common telescope assembly, and the lens assembly has the same function as the first convex lens 1041 and the second convex lens 1042, and is also used for contracting light beams. The light unifying part 101 in the projection apparatus shown in fig. 5 includes a fly-eye lens, and thus miniaturization of the projection apparatus can be ensured. Alternatively, the optical axes of the convex lens 1043 and the concave lens 1044 and the fly-eye lens may be collinear. It should be noted that, for the structures other than the convex lens 1043 and the concave lens 1044 in fig. 5, reference may be made to the related descriptions of the structures other than the first convex lens 1041, the second convex lens 1042 and the first diffusion sheet 105 in fig. 2 or fig. 4, and the description of the embodiments of the present application is not repeated.

Fig. 6 is a schematic structural diagram of another projection apparatus provided in an embodiment of the present application. Fig. 6 shows an overall appearance of an optical engine of a projection device, which may be an overall appearance of an optical engine of a projection device with any optional structure in the above embodiments. As shown in fig. 6, the projection apparatus includes: an optical engine 10, a light source 20 and a lens 30. The light source is used for emitting light to the optical machine 10, the optical machine 10 is used for modulating the incident light and then emitting the modulated light to the lens 30, and the lens 30 is used for projecting the incident light. For example, the optical engine 10 may include the first convex lens, the second convex lens, the first diffusion sheet, the second diffusion sheet, the light uniformizing element, the illumination lens group and the light valve in the projection apparatus.

The term "and/or" in this application is only one kind of association relationship describing the associated object, and means that there may be three kinds of relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship. The term "A, B and at least one of C" in this application means that there may be seven relationships that may mean: seven cases of A alone, B alone, C alone, A and B together, A and C together, C and B together, and A, B and C together exist. 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 "plurality" means two or more unless expressly limited otherwise.

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 light source is used for emitting light to the light valve, the light valve is used for modulating the incident light and then irradiating the modulated light to the lens, and the lens is used for projecting the incident light;

2. The projection device of claim 1, wherein a focal length of the first convex lens is greater than a focal length of the second convex lens.

3. The projection device of claim 1 or 2, wherein the ratio of the area of the light spot on the first convex lens to the area of the light spot on the second convex lens is in a range of 1.5-3.

4. The projection device of claim 1, wherein the light source is configured to emit laser light of at least two colors.

5. The projection apparatus according to claim 1 or 4, wherein a diffusion angle of the first diffusion sheet ranges from 8 degrees to 16 degrees.

6. The projection device of claim 1, wherein the light engine further comprises: the second diffusion sheet is positioned between the second convex lens and the light homogenizing part;

or the second diffusion sheet is positioned in the light path before the light rays emitted by the light source enter the first convex lens.

7. The projection apparatus of claim 6, wherein a diffusion angle of the second diffuser is smaller than a diffusion angle of the first diffuser.

8. The projection apparatus of claim 7, wherein a diffusion angle of the second diffusion sheet ranges from 1 degree to 6 degrees.

9. A projection device as claimed in any one of claims 6 to 8, characterized in that the first diffuser is a moving diffuser and the second diffuser is fixedly arranged.

10. The projection device of claim 1, wherein the light homogenizing component comprises a fly-eye lens.

11. The projection apparatus of claim 10, wherein the fly-eye lens comprises a plurality of lens units;

the fly-eye lens satisfies at least one of the following:

and the maximum distance range of both ends of the lens unit in the direction perpendicular to the optical axis is 0.5 mm to 1.5 mm.

12. The projection device of claim 1, wherein the projection device further comprises: the illuminating mirror group is positioned in a light path between the light homogenizing component and the light valve;

the illuminating mirror group comprises a third convex lens, a reflector plate, a fourth convex lens and a total internal reflection prism, light emitted by the light homogenizing component is emitted to the reflector plate through the third convex lens, the reflector plate is used for reflecting the emitted light to the fourth convex lens, the fourth convex lens is used for converging the emitted light to the total internal reflection prism, and the total internal reflection prism is used for reflecting the emitted light to the light valve.