Projection equipment

Abstract

The utility model discloses a projection device, comprising a projection light source used for emitting projection light; the fly-eye lens is located on a light emitting path of the projection light source; the fly-eye lens comprises a plurality of micro lenses with the same shape; the display element is located on a light emitting path of the fly-eye lens; the display element is used for performing brightness modulation on incident light according to image data of an image to be displayed to form a display image; the projection lens is located on a light emitting path of the display element; the projection lens comprises a diaphragm, and the shape of the diaphragm is the same as the shape of a micro lens in the fly-eye lens. The shape of the light spot emitted by the fly's-eye lens is determined by the shape of the micro lens in the fly's-eye lens, the shape of the diaphragm is designed to be the same as the shape of the micro lens, the shape of the light spot imaged by the fly's-eye lens at the diaphragm is the same as the shape of the diaphragm, and the diaphragm can intercept invalid light emitted by the display element through effective light emitted by the display element. And stray light in the projected image is reduced, so that the contrast of the projected image is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of projection display, in particular to a projection device. Background Art

[0002] Projection display technology uses a projection device to image the display image onto a projection screen for people to watch. The projection device includes a projection light source, a display element and a projection lens. The projection light source emits projection light to provide illumination for the display element. The display element modulates the incident light according to the image data of the image to be displayed to form a display image. The projection lens images the display image onto the projection screen.

[0003] Among them, the light emitted by the display element includes effective light and invalid light. Under ideal conditions, the effective light emitted by the display element is used to form a display image and enters the projection lens for imaging, while the invalid light cannot be emitted from the projection lens. However, in actual projection products, the invalid light emitted by the display element may enter the projection lens and eventually be emitted to the projection screen, forming stray light that interferes with the normal projection image, resulting in a decrease in the contrast of the projection image. Utility Model Content

[0004] The utility model provides a projection device, which is used for reducing stray light in the projection device, thereby improving the contrast of the projected image.

[0005] The utility model provides a projection device, which includes:

[0006] A projection light source, used for emitting projection light;

[0007] A fly-eye lens is located on the light path of the projection light source; the fly-eye lens includes a plurality of micro lenses of the same shape;

[0008] A display element is located on the light output path of the fly-eye lens; the display element is used to modulate the brightness of the incident light according to the image data of the image to be displayed to form a display image;

[0009] The projection lens is located on the light-emitting path of the display element; the projection lens includes an aperture, and the shape of the aperture is the same as that of the microlens in the fly-eye lens.

[0010] In some embodiments of the present invention, the microlens and the aperture are rectangular in shape.

[0011] In some embodiments of the present invention, the projection device further comprises a total reflection prism group, wherein the total reflection prism group is located between the display element and the projection lens;

[0012] The total reflection prism group includes a first prism, a second prism, and a third prism that are in contact with each other; the first prism includes a light incident surface, the surface of the first prism adjacent to the second prism and the third prism is a first total reflection interface, and the surface of the second prism adjacent to the third prism is a second total reflection interface;

[0013] The light emitted by the fly-eye lens is incident on the first total reflection interface from the light incident surface of the first prism, and is totally reflected by the first total reflection interface to the display element. The light emitted by the display element includes effective light and invalid light. The effective light is used for projection display. The effective light emitted by the display element is transmitted through the first total reflection interface to the second total reflection interface, is transmitted by the second total reflection interface and is incident on the projection lens. The invalid light emitted by the display element is transmitted through the first total reflection interface to the second total reflection interface and is totally reflected by the second total reflection interface.

[0014] In some embodiments of the present invention, the third prism includes a first light-emitting surface, and the effective light transmitted by the second total reflection interface is incident on the projection lens through the first light-emitting surface; and the light spot formed by the effective light emitted by the display element and projected onto the first light-emitting surface falls within the range of the first light-emitting surface.

[0015] In some embodiments of the present invention, the second prism includes a second light-emitting surface, and the invalid light reflected by the second total reflection interface is emitted through the second light-emitting surface;

[0016] The second light emitting surface and the first light emitting surface are arranged at a set angle, and the light rays emitted from the first light emitting surface and the second light emitting surface do not intersect.

[0017] In some embodiments of the present invention, the second light emitting surface is in contact with the first total reflection interface, and a position where the second light emitting surface is in contact with the first total reflection interface is spaced from an edge of the first total reflection interface;

[0018] The projection device further includes a light receiver, which is located on the light-emitting side of the second light-emitting surface.

[0019] In some embodiments of the present invention, the first light-emitting surface is connected to the first total reflection interface and the second total reflection interface respectively, the position where the first light-emitting surface is connected to the first total reflection interface coincides with the edge of the first total reflection interface, and the position where the first light-emitting surface is connected to the second total reflection interface coincides with the edge of the second total reflection interface.

[0020] In some embodiments of the present invention, the projection device further includes a total reflection prism group, the total reflection prism group including a first prism and a second prism; a surface of the first prism adjacent to the second prism is a first total reflection interface;

[0021] The light emitted from the fly-eye lens is incident on the first total reflection interface, is totally reflected by the first total reflection interface to the display element, is then reflected by the display element to the first total reflection interface, is transmitted through the first total reflection interface and is incident on the projection lens.

[0022] In some embodiments of the present invention, the fly-eye lens includes a substrate, a first fly-eye lens layer and a second fly-eye lens layer, wherein the first fly-eye lens layer and the second fly-eye lens layer are respectively located on the light incident side and the light exiting side surfaces of the substrate.

[0023] In some embodiments of the present invention, the projection device further includes an illumination lens group, and the illumination lens group is located on the optical path between the fly-eye lens and the display element.

[0024] The beneficial effects of the utility model are as follows:

[0025] The projection device provided by the utility model includes: a projection light source for emitting projection light; a compound eye lens located on the light output path of the projection light source; the compound eye lens including a plurality of micro lenses of the same shape; a display element located on the light output path of the compound eye lens; the display element for modulating the brightness of incident light according to image data of an image to be displayed to form a display image; a projection lens located on the light output path of the display element; the projection lens including an aperture, the shape of the aperture being the same as the shape of the micro lenses in the compound eye lens. The shape of the light spot emitted by the compound eye lens is determined by the shape of the micro lenses in the compound eye lens. If the aperture shape is designed to be the same as the shape of the micro lenses, the shape of the light spot imaged by the compound eye lens at the aperture is the same as the shape of the aperture. The aperture can intercept the ineffective light emitted by the display element while allowing the effective light emitted by the display element to pass through, thereby reducing stray light in the projected image and improving the contrast of the projected image. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings introduced below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 A schematic structural diagram of a projection device provided in an embodiment of the present utility model;

[0028] Figure 2 A schematic diagram of an imaging spot at an aperture provided by an embodiment of the present utility model;

[0029] Figure 3 A schematic diagram of a planar structure of a projection light source provided by an embodiment of the utility model;

[0030] Figure 4 A schematic diagram of a combined light spot at a fly-eye lens provided in an embodiment of the present utility model;

[0031] Figure 5 A schematic structural diagram of a compound eye lens provided in an embodiment of the present utility model;

[0032] Figure 6 A schematic structural diagram of a total reflection prism assembly provided by an embodiment of the present utility model;

[0033] Figure 7 A schematic diagram of the optical path of effective light provided by an embodiment of the utility model;

[0034] Figure 8 A schematic diagram of the optical path of invalid light provided in an embodiment of the utility model;

[0035] Figure 9 A schematic structural diagram of another projection device provided by an embodiment of the present utility model;

[0036] Figure 10 A schematic structural diagram of another projection device provided by an embodiment of the present utility model;

[0037] Description of reference numerals:

[0038] 1-projection light source, 2-fly-eye lens, 3-display element, 4-projection lens, A-aperture, P-light spot, 5-light combining mirror group, 6-light uniformity component, 7-illumination lens group, 8-total reflection prism group, 9-projection screen, R-red laser chip, G-green laser chip, B-blue laser chip, 51-first light combining mirror, 52-second light combining mirror, 53-third light combining mirror, 61-first diffuser, 62-second diffuser, 21-substrate, 22-first fly-eye lens layer, 23-second fly-eye lens layer, 220-first microlens, 230-second microlens, 81-first prism, 82-second prism, 83-third prism, S1-light incident surface, S2-first total reflection interface, S3-second total reflection interface, S4-first light exit surface, S5-second light exit surface, 10-light receiver DETAILED DESCRIPTION

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention will be further described below with reference to the accompanying drawings and examples. However, the example embodiments can be implemented in various forms and should not be understood as being limited to the embodiments described herein; on the contrary, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concepts of the example embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and their repeated descriptions will be omitted. The words expressing position and direction described in the present invention are all explained with reference to the accompanying drawings as examples, but changes can be made as needed, and all changes are included in the scope of protection of the present invention. The drawings of the present invention are only used to illustrate the relative position relationship and do not represent the true proportion.

[0040] Figure 1 The present invention provides a schematic structural diagram of a projection device according to an embodiment of the present invention.

[0041] like Figure 1 As shown, the projection device includes: a projection light source 1, a fly-eye lens 2, a display element 3, and a projection lens 4. The projection light source 1 is used to emit projection light; the fly-eye lens 2 is located on the light output path of the projection light source 1, the display element 3 is located on the light output path of the fly-eye lens 2, and the projection lens 4 is located on the light output path of the display element 3.

[0042] The working principle of the fly-eye lens 2 is as follows: the fly-eye lens 2 includes two fly-eye lens layers, each of which includes multiple microlenses of the same shape, and the microlenses in the two fly-eye lens layers are arranged in a one-to-one correspondence. The incident light beam is split into multiple sub-beams by the fly-eye lens on the light-entering side. Since the microlenses on the light-exiting side are arranged on the focal plane of the corresponding microlenses on the light-entering side, the sub-beams can be collimated into parallel light at the corresponding microlenses on the light-exiting side, and the shape of the sub-spot imaged by the sub-beam is the same as the shape of the microlens. The superposition of multiple sub-spots can form a more uniform imaging spot, and the shape of the imaging spot is the same as the shape of each sub-spot. It can be seen that the shape of the microlenses in the fly-eye lens 2 determines the shape of its imaging spot, and the shape of the microlenses in the fly-eye lens 2 is the same as the shape of the spot imaged by the light beam emitted by the fly-eye lens 2.

[0043] Display element 3 is used to modulate the brightness of incident light based on the image data of the image to be displayed, forming a displayed image. Display element 3 does not change the shape of the incident light spot. Projection lens 4 projects the image formed by the display element at a certain distance to form a projected image. Ideally, the light emitted by projection lens 4 should be the light emitted by display element 3 for projection display, referred to as effective light. Light not used for projection display, referred to as ineffective light, should be prevented from exiting projection lens 4. To intercept ineffective light emitted by display element 3, projection lens 4 is provided with an aperture A.

[0044] The projection device in the embodiment of the present invention is designed based on the Kohler illumination principle, and the light beam emitted by the fly-eye lens 2 is imaged at the aperture A. Figure 2 A schematic diagram of an imaging spot at an aperture provided by an embodiment of the present invention, which exemplarily shows the shape of the aperture A and the imaging spot P at the aperture A when the shape of the microlens in the fly-eye lens 2 is rectangular.

[0045] In the embodiment of the present invention, the shape of the aperture A is designed to be the same as the shape of the microlens in the fly-eye lens 2, such as Figure 2 As shown, when the shape of the microlens in the fly-eye lens 2 is rectangular, the shape of the imaging spot P at the aperture A is also rectangular. If the shape of the aperture A is designed to be rectangular, the shape of the aperture A is the same as the shape of the imaging spot P at the aperture A.

[0046] In order to make the effect of the embodiment of the utility model more intuitive and visible, Figure 2 A circular aperture A' is also shown in dashed lines for comparison. Figure 2 As shown, when the shape of the aperture A' is different from the shape of the microlenses in the fly-eye lens 2, in order for the effective light emitted by the display element 3 to pass completely through the aperture A' and be utilized, the circular aperture A' should at least be circumscribed to the rectangular imaging spot P. As a result, there will inevitably be a gap between the edge of the aperture A' and the edge of the imaging spot P. In this case, ineffective light emitted by the display element 3 may pass through the aperture A' through this gap, be imaged by the projection lens 4, and affect the contrast of the projected image. The same applies to apertures A' of other shapes.

[0047] It can be seen that the embodiment of the present invention designs the aperture A and the microlenses in the fly-eye lens 2 to have the same shape, which facilitates matching the size of the aperture A with the size of the imaging spot P and eliminates the gap between the edge of the aperture A' and the edge of the imaging spot P. As a result, the aperture A can pass the effective light emitted by the display element 3 while intercepting the invalid light emitted by the display element 3, preventing the invalid light from mixing with the effective light and being emitted by the projection lens 4 to form stray light, which is beneficial to improving the contrast of the projected image.

[0048] In practical applications, the microlenses in the fly-eye lens 2 and the aperture A may also adopt other shapes, such as hexagonal, octagonal or circular, etc., and the imaging spot P at the aperture A can also be matched with the shape and size of the aperture A, thereby allowing effective light to pass while intercepting invalid light, thereby improving the contrast of the projected image.

[0049] Based on the above concept, the specific structure of the projection device is described below. Figure 1 As shown, the projection device includes a projection light source 1, a light combining lens group 5, a light homogenizing component 6, a fly-eye lens 2, an illumination lens group 7, a total reflection prism group 8, a display element 3 and a projection lens 4 arranged in sequence along the propagation direction of the light path.

[0050] Among them, the projection light source 1 can adopt a laser light source to meet the demand for high brightness. For example, a small laser (Multi Chip Laser, abbreviated as MCL) can be adopted, but it is not limited to this. MCL has the advantages of long life, high brightness, high power, etc., and MCL occupies a small space, which is in line with the development trend and design requirements of miniaturization of projection equipment.

[0051] In the embodiment of the present invention, the projection light source 1 adopts a three-color MCL laser, and the red laser chip R, the green laser chip G and the blue laser chip B are arrayed in the MCL laser, which are used to emit red laser, green laser and blue laser respectively.

[0052] Figure 3 A schematic diagram of a planar structure of a projection light source provided by an embodiment of the utility model.

[0053] like Figure 3 As shown, the projection light source 1 in this embodiment of the present invention has four rows and seven columns of laser chips, including two rows and seven columns of red laser chips R, one row and seven columns of green laser chips G, and one row and seven columns of blue laser chips B. Each laser chip emits an elliptical light spot. In actual applications, the projection light source 1 may also use other numbers of laser chips arranged in other arrangements. This embodiment of the present invention is for illustrative purposes only and does not limit the specific number or arrangement of laser chips.

[0054] like Figure 1 As shown, a light-combining mirror group 5 is provided on the light-emitting side of the projection light source 1. The light-combining mirror group 5 is used to combine the red laser, the green laser, and the blue laser. The light-combining mirror group 5 can be composed of a reflector and a dichroic mirror. In the embodiment of the present invention, the light-combining mirror group 5 includes a first light-combining mirror 51, a second light-combining mirror 52, and a third light-combining mirror 53.

[0055] The first light combining mirror 51 is located on the light-emitting side of the green laser chip G. The first light combining mirror 51 can be a reflective mirror for reflecting the green laser light emitted by the green laser chip G toward the second light combining mirror 52 .

[0056] The second light-combining mirror 52 is located at the intersection of the reflected light path of the first light-combining mirror 51 and the light path of the blue laser chip B. The second light-combining mirror 52 can be a dichroic mirror, which is used to transmit the green laser reflected by the first light-combining mirror 51 and reflect the blue laser emitted by the blue laser chip B, thereby combining the blue and green laser beams.

[0057] The third beam combiner 53 is located at the intersection of the light output path of the second beam combiner 52 and the light output path of the red laser chip R. The third beam combiner 53 can be a dichroic mirror, which is used to transmit the blue laser and green laser light emitted by the second beam combiner 52 and reflect the red laser light emitted by the red laser chip R, thereby combining the blue laser light, the green laser light, and the red laser light.

[0058] A light homogenizing component 6 can also be provided in the light-combining optical path of the light-combining lens assembly 5 to homogenize the combined light beam and reduce laser speckle. The light homogenizing component 6 can be, for example, a static diffuser, a vibrating diffuser, or a rotating diffuser, among others, to change the phase of the incident laser light, thereby disrupting the laser's coherence and reducing the speckle effect. In practical applications, the number, type, and arrangement of the light homogenizing components 6 in the projection device can be designed based on actual needs. The embodiments of the present utility model are merely illustrative and do not limit the specific design of the light homogenizing component 6.

[0059] like Figure 1 As shown, in the embodiment of the present invention, a first diffuser 61 and a second diffuser 62 are provided on the light-emitting side of the light-combining lens group 5 as light-uniform components. The first diffuser 61 is a static diffuser, and the second diffuser 62 is a vibrating diffuser. The combined light beam emitted by the light-combining lens group 5 is projected onto the fly-eye lens 2 after passing through the first diffuser 61 and the second diffuser 62, so that the combined light spot projected onto the fly-eye lens 2 has better uniformity.

[0060] Figure 4 A schematic diagram of a light-combining spot at a compound eye lens provided in an embodiment of the present utility model.

[0061] like Figure 4 As shown, the red laser spot, green laser spot and blue laser spot projected onto the fly-eye lens 2 are all circular spots. There is overlap between the laser spots of different colors, and the overall shape of the combined light spot is approximately rectangular.

[0062] Figure 5 This is a schematic structural diagram of a compound eye lens provided in an embodiment of the present utility model.

[0063] like Figure 5 As shown, in this embodiment of the present invention, the fly-eye lens 2 includes a substrate 21, a first fly-eye lens layer 22, and a second fly-eye lens layer 23. The first fly-eye lens layer 22 and the second fly-eye lens layer 23 are respectively located on the light-incident and light-exiting surfaces of the substrate 21. The integration of the two fly-eye lens layers helps reduce the size of the projection device and also reduces errors during assembly.

[0064] Reference Figure 4 and Figure 5 The first fly-eye lens layer 22 and the second fly-eye lens layer 23 each include a plurality of microlenses. For ease of description, the microlenses in the first fly-eye lens layer 22 are referred to as first microlenses 220, and the microlenses in the second fly-eye lens layer 23 are referred to as second microlenses 230. The first microlenses 220 and the second microlenses 230 are arranged in a one-to-one correspondence, and the second microlenses 230 are located on the focal plane of the corresponding first microlenses 220.

[0065] The light beam incident on the fly-eye lens 2 can be split into multiple sub-beams by the multiple first microlenses 220 in the first fly-eye lens layer 22. The uniformity of each sub-beam is better than that of the entire beam. The sub-beams are converged by the first microlenses 220 to the center of the corresponding second microlenses 230. They can be collimated into parallel light through the second microlenses 230 and emitted. The shape of the sub-spot formed by the sub-beams is the same as that of the second microlenses 230. The light beam emitted by the second fly-eye lens layer 23 is formed by the superposition of the collimated sub-beams emitted by each second microlens 230. The light spot formed by this light beam is formed by the superposition of multiple sub-spots, which can have better uniformity, and the shape of the imaged light spot is the same as that of each sub-spot.

[0066] It can be seen that the light beam emitted by the fly-eye lens 2 has better uniformity than the incident light beam. The fly-eye lens 2 has the function of homogenizing the light beam. At the same time, the fly-eye lens 2 can shape the output light spot into the same shape as the microlens in the fly-eye lens 2, so that the shape of the imaging light spot P at the aperture A is the same as the shape of the microlens in the fly-eye lens 2.

[0067] In practical applications, a two-piece fly-eye lens can also be used, including a first fly-eye lens and a second fly-eye lens. The first fly-eye lens includes a plurality of first microlenses 220, and the second fly-eye lens includes a plurality of second microlenses 230. The correspondence and operating principle of the first microlenses 220 and the second microlenses 230 can be referred to the above description and will not be repeated here. The first fly-eye lens and the second fly-eye lens can be provided separately, that is, other optical components can be provided between them. For example, a light homogenization component 6 and a lens can be provided between the first fly-eye lens 2 and the second fly-eye lens 2.

[0068] The projection device may also include an illumination lens assembly 7, located in the optical path between the fly-eye lens 2 and the display element 3. The illumination lens assembly 7 is configured to converge or diverge the light beam emitted by the fly-eye lens 2 so that the size of the light spot formed when the light beam is projected onto the display element 3 matches the size of the effective area of the display element 3, thereby fully utilizing the light. The number and spacing of the illumination lenses in the illumination lens assembly 7, as well as the surface parameters of each illumination lens, such as the radius of curvature, optical power, and thickness, can be optically designed based on product requirements and are not limited in this regard by the present invention.

[0069] Depending on the projection technology used, different types of display elements 3 can be used in the projection device, such as a liquid crystal display (LCD) or a digital micromirror device (DMD). Embodiments of the present invention can utilize digital light processing (DLP) technology and use a DMD as the display element 3, which has the advantages of high optical efficiency and small size.

[0070] Thousands of reflective micromirrors are arrayed within the active area of the DMD. These micromirrors, driven by a rotating mechanism beneath them under control signals, rapidly adjust their angle and direction, turning them on or off. By controlling the deflection state and timing of each micromirror in the DMD, the brightness and contrast of the displayed image can be modulated. The micromirrors, when in the on and off states, reflect incident light in different directions. Light reflected by micromirrors in the on state is used to form the displayed image and is considered effective light, destined to enter the projection lens 4. Light reflected by micromirrors in the off state is considered ineffective light and must be prevented from entering the projection lens 4.

[0071] like Figure 1 As shown, the projection device further includes a total reflection prism assembly 8, which is located between the display element 3 and the projection lens 4. Light can be totally reflected within the total reflection prism assembly 8, thereby folding the internal optical path thereof, achieving a longer optical path within a smaller spatial volume, which helps to reduce the overall size of the projection device and meets the design requirements of miniaturization.

[0072] Figure 6 This is a schematic structural diagram of a total reflection prism assembly provided in an embodiment of the present utility model.

[0073] The total reflection prism group 8 includes a first prism 81, a second prism 82 and a third prism 83 that are in contact with each other, wherein the first prism 81 includes a light incident surface S1, the surface of the first prism 81 adjacent to the second prism 82 and the third prism 83 is a first total reflection interface S2, and the surface of the second prism 82 adjacent to the third prism 83 is a second total reflection interface S3.

[0074] Figure 7 A schematic diagram of the optical path of effective light provided by an embodiment of the utility model; Figure 8 A schematic diagram of the optical path of the invalid light provided in an embodiment of the present utility model.

[0075] Reference Figures 6 to 8 The light emitted from the fly-eye lens 2 is first incident on the first total reflection interface S2 by the light incident surface S1 of the first prism 81. Its incident angle meets the total reflection condition and can be totally reflected by the first total reflection interface S2 to the display element 3. The light reflected back by the display element 3 will be incident on the first total reflection interface S2 again, but at this time the incident angle of the light no longer meets the total reflection condition, so it will be transmitted by the first total reflection interface S2 to the second total reflection interface S3.

[0076] Reference Figure 6 and Figure 7 The effective light emitted by the display element 3 is transmitted through the first total reflection interface S2 to the second total reflection interface S3. The incident angle at the second total reflection interface S3 does not meet the total reflection condition, so the effective light can be transmitted by the second total reflection interface S3 and enter the projection lens 4, and is imaged by the projection lens 4 on the projection screen 9.

[0077] Specifically, the third prism 83 includes a first light-emitting surface S4. The effective light transmitted by the second total reflection interface S3 enters the third prism 83 and is incident on the projection lens 4 through the first light-emitting surface S4. The light spot formed by the effective light emitted by the display element 3 and projected onto the first light-emitting surface S4 should fall within the range of the first light-emitting surface S4 to ensure that all the effective light can pass through the first light-incident surface S1 and enter the projection lens 4 to be utilized, thereby avoiding the loss of effective light.

[0078] Reference Figure 6 and Figure 8 Ineffective light emitted by display element 3 is transmitted through first total reflection interface S2 to second total reflection interface S3. The incident angle at second total reflection interface S3 satisfies the total reflection condition, so the ineffective light is totally reflected by second total reflection interface S3. This separates the effective light from the ineffective light at second total reflection interface S3, preventing the ineffective light from affecting the image quality of the projected image.

[0079] Specifically, the second prism 82 includes a second light-emitting surface S5, through which the ineffective light reflected by the second total reflection interface S3 is emitted. The second light-emitting surface S5 is arranged at a predetermined angle to the first light-emitting surface S4, so that the light rays emitted from the first light-emitting surface S4 and the second light-emitting surface S5 do not intersect, thereby preventing the ineffective light rays from mixing with the effective light rays.

[0080] Figure 9 This is a structural schematic diagram of another projection device provided by an embodiment of the present utility model.

[0081] like Figure 9 As shown, in an embodiment of the present invention, the projection device may further include a light receiver 10, which is located on the light-emitting side of the second light-emitting surface S5. The light receiver 10 can receive invalid light totally reflected by the second total reflection interface S3, thereby preventing the invalid light from propagating inside the projection device and interfering with the light propagation in other optical components.

[0082] Reference Figure 8 and Figure 9 In the total reflection prism group 8, the second light-emitting surface S5 is connected to the first total reflection interface S2. Under the premise of ensuring that the areas of the first total reflection interface S2 and the second total reflection interface S3 are large enough, the size of the second prism 82 can be appropriately reduced so that the position where the second light-emitting surface S5 is connected to the first total reflection interface S2 is spaced from the edge of the first total reflection interface S2, thereby providing an accommodation space for the arrangement of the light receiver 10, improving the utilization rate of the internal space of the projection device, and being conducive to improving the integration of the projection device and further realizing miniaturization.

[0083] Reference Figure 6 The first light-emitting surface S4 is connected to the first total-reflection interface S2 and the second total-reflection interface S3 respectively. To ensure that the areas of the first total-reflection interface S2 and the second total-reflection interface S3 are large enough to avoid light loss, the position where the first light-emitting surface S4 is connected to the first total-reflection interface S2 can coincide with the edge of the first total-reflection interface S2, and the position where the first light-emitting surface S4 is connected to the second total-reflection interface S3 can coincide with the edge of the second total-reflection interface S3.

[0084] Figure 10 This is a structural schematic diagram of another projection device provided by an embodiment of the present utility model.

[0085] like Figure 10As shown, in an embodiment of the present invention, the total reflection prism group 8 may include a first prism 81 and a second prism 82, and the surface of the first prism 81 adjacent to the second prism 82 is a first total reflection interface S2; the light emitted by the compound eye lens 2 is incident on the first total reflection interface S2, is totally reflected by the first total reflection interface S2 to the display element 3, and is then reflected by the display element 3 to the first total reflection interface S2, is transmitted through the first total reflection interface S2 and is incident on the projection lens 4, and is then imaged by the projection lens 4 on the projection screen 9.

[0086] In the embodiment of the present invention, even if some invalid light may be mixed with the effective light and enter the projection lens 4, the aperture A in the projection lens 4 can also block the invalid light, so that it cannot exit the projection lens 4 and affect the quality of the projected image. The design of the aperture A can refer to Figure 1 and Figure 2 The total reflection prism group 8 in the embodiment of the present invention has a relatively simple structure, low design difficulty and low process difficulty, and can be applied to products requiring low cost.

[0087] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0088] Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations.

Claims

1. A projection device, characterized in that: The projection device comprises: A projection light source, used for emitting projection light; A fly-eye lens is located on the light path of the projection light source; the fly-eye lens includes a plurality of micro lenses of the same shape; A display element is located on the light output path of the fly-eye lens; the display element is used to modulate the brightness of the incident light according to the image data of the image to be displayed to form a display image; The projection lens is located on the light-emitting path of the display element; the projection lens includes an aperture, and the shape of the aperture is the same as that of the microlens in the fly-eye lens.

2. The projection device according to claim 1, wherein: The microlens and the aperture are rectangular in shape.

3. The projection device according to claim 1, wherein: The projection device further includes a total reflection prism group, wherein the total reflection prism group is located between the display element and the projection lens; The total reflection prism group includes a first prism, a second prism, and a third prism that are in contact with each other; the first prism includes a light incident surface, the surface of the first prism adjacent to the second prism and the third prism is a first total reflection interface, and the surface of the second prism adjacent to the third prism is a second total reflection interface; The light emitted by the fly-eye lens is incident on the first total reflection interface from the light incident surface of the first prism, and is totally reflected by the first total reflection interface to the display element. The light emitted by the display element includes effective light and invalid light. The effective light is used for projection display. The effective light emitted by the display element is transmitted through the first total reflection interface to the second total reflection interface, is transmitted by the second total reflection interface and is incident on the projection lens. The invalid light emitted by the display element is transmitted through the first total reflection interface to the second total reflection interface and is totally reflected by the second total reflection interface.

4. The projection device according to claim 3, wherein: The third prism includes a first light-emitting surface, and the effective light transmitted by the second total reflection interface is incident on the projection lens through the first light-emitting surface; and the light spot formed by the effective light emitted by the display element projected onto the first light-emitting surface falls within the range of the first light-emitting surface.

5. The projection device according to claim 4, wherein: The second prism includes a second light-emitting surface, and the invalid light reflected by the second total reflection interface is emitted through the second light-emitting surface; The second light emitting surface and the first light emitting surface are arranged at a set angle, and the light rays emitted from the first light emitting surface and the second light emitting surface do not intersect.

6. The projection device according to claim 5, wherein: The second light emitting surface is in contact with the first total reflection interface, and a position where the second light emitting surface is in contact with the first total reflection interface is spaced from an edge of the first total reflection interface; The projection device further includes a light receiver, which is located on the light-emitting side of the second light-emitting surface.

7. The projection device according to any one of claims 4 to 6, characterized in that: The first light emitting surface is connected to the first total reflection interface and the second total reflection interface respectively, the position where the first light emitting surface is connected to the first total reflection interface coincides with the edge of the first total reflection interface, and the position where the first light emitting surface is connected to the second total reflection interface coincides with the edge of the second total reflection interface.

8. The projection device according to claim 1, wherein: The projection device further includes a total reflection prism group, the total reflection prism group includes a first prism and a second prism; the surface of the first prism adjacent to the second prism is a first total reflection interface; The light emitted from the fly-eye lens is incident on the first total reflection interface, is totally reflected by the first total reflection interface to the display element, is then reflected by the display element to the first total reflection interface, is transmitted through the first total reflection interface and is incident on the projection lens.

9. The projection device according to claim 1, wherein: The fly-eye lens includes a substrate, a first fly-eye lens layer and a second fly-eye lens layer. The first fly-eye lens layer and the second fly-eye lens layer are respectively located on the light incident side and the light exit side of the substrate.

10. The projection device according to claim 1, wherein: The projection device further includes an illumination lens group located on an optical path between the fly-eye lens and the display element.

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