DLP (Digital Light Processing) projection module with gun-shaped framework

Abstract

The invention relates to the technical field of projection modules, and particularly discloses a DLP projection module with a gun-shaped framework, which comprises a light source module, the light source module is provided with a light source optical axis, a fly's-eye lens is arranged on the light emitting side of the light source module, a sub-lens protrudes from the surface of the fly's-eye lens, and a first included angle is formed between the sub-lens and the light source optical axis. The relay lens module is arranged on the light-emitting side of the fly-eye lens, the relay lens module is provided with two light-emitting sides, the DMD chip is arranged on one light-emitting side of the relay lens module, the projection lens is arranged on the other light-emitting side of the relay lens module, the projection lens is provided with a projection optical axis, and the DMD chip is arranged on the other light-emitting side of the relay lens module. The included angle between the projection optical axis and the light source optical axis on the same plane is a second included angle; and the projection lens is used for receiving the image light turned by the relay lens module. Wherein the value of the first included angle is the same as that of the second included angle, and the value of the first included angle and the value of the second included angle are both 40-80 degrees, so that the DLP projection module of the gun-shaped structure is ensured to meet the miniaturization design requirement.

Description

Technical Field

[0001] This invention relates to the field of projection module technology, and specifically to a gun-shaped DLP projection module. Background Technology

[0002] As projection systems are applied in increasingly wider fields, the requirements for projection generation units (PGUs) are also becoming more stringent. DLP technology is widely used, offering significant advantages over traditional LCD projection technology in terms of light efficiency, clarity, brightness, and contrast.

[0003] However, existing DLP projection modules are either too long or too wide due to the arrangement of their internal structures and the design of their optical components, which does not meet the requirements for miniaturization. Summary of the Invention

[0004] This invention discloses a gun-shaped DLP projection module, the purpose of which is to solve at least one of the technical problems existing in the prior art.

[0005] This invention provides a gun-shaped DLP projection module, comprising: a light source module having a light source optical axis for emitting light rays propagating along the light source optical axis; a compound eye lens disposed on the light-emitting side of the light source module, the compound eye lens being rectangular in shape, having a plurality of sub-lenses disposed on its surface, the sub-lenses being arranged in an array, and the line connecting the center points of the sub-lenses forming a first angle with the bottom edge of the compound eye lens; and a relay lens module disposed on the light-emitting side of the compound eye lens for receiving light rays from the compound eye lens and redirecting the light rays, wherein the relay lens module has two light-emitting sides. A DMD chip is disposed on one of the light-emitting sides of the relay lens module, used to receive light from the relay lens module and convert the light into image light and project it back to the relay lens module; a projection lens is disposed on the other light-emitting side of the relay lens module, the projection lens has a projection optical axis, the projection optical axis is parallel to the light source optical axis, and the angle between the projection optical axis and the light source optical axis on the same plane is a second angle, the projection lens is used to receive image light redirected by the relay lens module; wherein, the first angle and the second angle have the same value, and the value range of the first angle and the second angle is 40° to 80°.

[0006] In some embodiments of the present invention, the light source module includes three corresponding light sources, three collimating lens assemblies, and three reflectors. The light emitted by the light source is directed to the reflector through the collimating lens assembly and, after being reflected by the reflector, propagates along the optical axis of the light source. The three light sources are arranged in sequence as a blue light source, a green light source, and a red light source along the optical axis of the light source and toward the compound eye lens, and the three reflectors are arranged in sequence as a blue reflector, a green dichroic mirror, and a red dichroic mirror.

[0007] In some embodiments of the present invention, the collimating lens assembly includes a first collimating lens and a second collimating lens, the first collimating lens being close to the light source, and the combined focal length of the first collimating lens and the second collimating lens being 6.56 mm to 7.06 mm.

[0008] In some embodiments of the present invention, the green dichroic mirror and the red dichroic mirror are both placed at a 45° angle to the optical axis of the light source, and a collimation compensation lens is provided between the green dichroic mirror and the red dichroic mirror, the focal length of the collimation compensation lens being 75mm to 105mm.

[0009] In some embodiments of the present invention, the collimation compensation lens is a plano-convex cylindrical lens, the collimation compensation lens includes two parallel cut surfaces, and the angle between the cut surfaces and the bottom edge of the compound eye lens is 50°±15°.

[0010] In some embodiments of the present invention, the compound eye lens includes a first surface facing the light source module and a second surface facing away from the first surface, the sub-lens is disposed on the second surface, the distance between the first surface and the second surface on the optical axis of the light source is 8mm to 13mm, and the sagitta of the sub-lens on the compound eye lens is 0.1mm to 0.2mm.

[0011] In some embodiments of the present invention, the relay lens module includes a first relay lens, a first reflector, a second relay lens, and a right-angle prism arranged sequentially. The first relay lens is disposed along the optical axis of the light source on the light-emitting side of the compound eye lens. The first reflector is disposed on the light-emitting side of the first relay lens, and the first reflector has a reflective surface, which is arranged at a 45° angle to the optical axis of the light source. The second relay lens is disposed facing the reflective surface and receives the light reflected from the reflective surface. The right-angle prism is disposed on the light-emitting side of the second relay lens. The right-angle prism is made of glass, and its refractive index Nd is 1.60–1.65, and its dispersion coefficient Vd is greater than 30.

[0012] In some embodiments of the present invention, the right-angle prism includes a first light-incident surface, a first light-exiting surface, and a second light-exiting surface. The first light-incident surface forms an angle with the first light-exiting surface and the second light-exiting surface, and the first light-exiting surface and the second light-exiting surface are arranged perpendicularly. The first light-incident surface is located on the light-exiting side of the second relay lens. The DMD chip faces the first light-exiting surface, and the projection lens faces the second light-exiting surface.

[0013] In some embodiments of the present invention, the focal length of the first relay lens is 61mm to 66mm, the focal length of the second relay lens is 33mm to 38mm, and the angle between the optical axis of the second relay lens and the optical axis of the light source is 40° to 50°. The distance between the center point of the compound eye lens and the center point of the first relay lens on the optical axis of the light source is greater than 1.5mm, and the distance between the center point of the first relay lens and the center point of the first reflector on the optical axis of the light source is greater than 12.5mm.

[0014] In some embodiments of the present invention, the total length of the projection lens is 53mm to 57mm, and the effective focal length of the projection lens is 18mm to 21mm. Attached Figure Description

[0015] Figure 1 A schematic diagram of the gun-shaped DLP projection module provided by the present invention;

[0016] Figure 2 for Figure 1 A bottom view of the DLP projection module with a gun-shaped architecture in the middle;

[0017] Figure 3 This is a view of the compound eye lens provided by the present invention along the optical axis of the light source. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] The gun-shaped DLP projection module provided in the embodiments of this application will be further described in detail below with reference to the accompanying drawings.

[0022] In this embodiment, as Figures 1 to 3 As shown, a gun-shaped DLP projection module is proposed. Along the light transmission path, a light source module 1, a compound eye lens 2, a relay lens module 3, a DMD chip 4, and a projection lens 5 are arranged sequentially. The light source module 1 has a light source optical axis X and is used to emit light rays that travel along the light source optical axis X. The compound eye lens 2 is used to receive the light rays from the light source module 1 and homogenize them. The relay lens module 3 is used to receive the light rays from the compound eye lens 2, homogenize them, and adjust their transmission direction. The DMD chip 4 is used to receive the light rays from the relay lens module 3, convert them into image light carrying image information, and project it back to the relay lens module 3. The relay lens module 3 then transmits the image light to the projection lens 5, which finally shapes the image light and projects it out, thus completing the entire projection process of the gun-shaped DLP projection module.

[0023] Specifically, the compound eye lens 2 is located on the light-emitting side of the light source module 1. The compound eye lens 2 has a rectangular shape, and multiple sub-lenses 21 are disposed on the surface of the compound eye lens 2. The sub-lenses 21 are arranged in an array on the surface of the compound eye lens 2, wherein the line o connecting the center points of the sub-lenses 21 forms a first angle α with the bottom edge 22 of the compound eye lens 2. For ease of understanding, Figure 3The view of the compound eye lens 2 given is observed along the X-axis of the light source. The bottom edge 22 of the compound eye lens 2 refers to the lowest edge of the compound eye lens 2 as observed along the X-axis. It should be noted that a conventional compound eye lens 2 is rectangular in shape, and the sub-lenses 21 on its surface are also arranged in an array. However, the existing array arrangement of the sub-lenses 21 is horizontal and vertical, meaning the array arrangement of the sub-lenses 21 is parallel to the side length of the compound eye lens 2. Traditionally, the line connecting the center points of the sub-lenses is parallel to the side length of the compound eye lens. In this design, the array arrangement of sub-lenses 21 on the surface of the compound eye lens 2 is changed to an inclined arrangement. Specifically, the line connecting the sub-lenses 21 is designed to have a first angle α with the bottom edge 22 of the compound eye lens 2. This causes the light spot formed by the convergence of light passing through the compound eye lens 2 to rotate, and the light spot relative to the optical axis X of the light source rotates to adapt to the DMD chip 4 and the projection lens 5. This ensures that the light spot formed by the light passing through the compound eye lens 2 can be captured by the DMD chip 4, that is, the shape of the light spot is adapted to the setting position and orientation of the DMD chip 4. It can be understood that the array arrangement of the sub-lenses 21 in this design can be understood as rotating the traditional array arrangement of sub-lenses 21 relative to the optical axis X of the light source by a first angle α, thereby causing the compound eye lens 2 to rotate the light passing through it, and the light converges to form a light spot. This ensures that the rotated light spot can perfectly adapt to the DMD chip 4 placed behind it. The setting orientation of the DMD chip 4 is to ensure that the projection lens 5 can obtain sufficient light for projection. Among them, the line o connecting the center points of the sub-lens 21 refers to the line connecting the center points of a certain row and column of sub-lens 21, that is, the line connecting the center points of a group of sub-lenses 21 arranged in an array.

[0024] For further information, please refer to [the website / platform / etc.] again. Figure 1 and Figure 2 The relay lens module 3 is located on the light-emitting side of the compound eye lens 2, used to receive light from the compound eye lens 2 and redirect the light. The relay lens module 3 has two light-emitting sides. The DMD chip 4 is located on one of the light-emitting sides of the relay lens module 3, used to receive light from the relay lens module 3 and convert the light into image light, which is then projected back to the relay lens module 3. The projection lens 5 is located on the other light-emitting side of the relay lens module 3. The projection lens 5 has a projection optical axis Y, which is parallel to the light source optical axis X. The projection optical axis Y and the light source optical axis X have a second angle b. The projection lens 5 is used to receive the image light redirected by the relay lens module 3. It should be noted that the relay lens module 3 places the light source module 1 and the projection lens 5 on different horizontal planes; that is, the projection optical axis Y and the light source optical axis X are also on different horizontal planes. The second angle b between the projection optical axis Y and the light source optical axis X refers to the angle between the projection optical axis Y and the light source optical axis X on the same plane. For example, as... Figure 2As shown, a plane parallel to the light source optical axis X is drawn based on the projection optical axis Y. The light source optical axis X is projected onto this plane. At this time, the angle between the projection line of the light source optical axis X and the projection optical axis Y is the second angle b.

[0025] In this design, the first included angle 'a' and the second included angle 'b' have the same value, and their values ​​range from 40° to 80°. By setting the light source optical axis X and the projection optical axis Y at the second included angle 'b', that is, arranging the light source module 1 and the projection lens 5 at the second included angle 'b', the DLP projection module adopts a gun-shaped architecture. This significantly shortens the length of the DLP projection module and controls its width, ensuring that the gun-shaped architecture meets the miniaturization design requirements. Simultaneously, the rational arrangement of the internal components of the DLP projection module, i.e., setting the light source module 1 and the projection lens 5 at an angle, facilitates better centralized installation of the DLP projection module's heat dissipation structure, preventing the projection lens 5 from interfering with the installation of the heat dissipation structure of the light source module 1.

[0026] It is understandable that by designing the line o connecting the center points of the sub-lenses of the compound eye lens 2 and the bottom edge 22 of the compound eye lens 2 to have a first included angle α, the compound eye lens 2 can redirect and adjust the light passing through it. In order to ensure that the DMD chip 4 and the projection lens 5 can match and receive the light redirected by the compound eye lens 2, the light source optical axis X and the projection optical axis Y are also designed to have a second included angle β, where the first included angle α and the second included angle β have the same value. In this design, the compound eye lens 2, together with the relay lens module 3, allows the light to be transmitted along the light source optical axis X while rotating around the light source optical axis X. The light source optical axis X and the projection optical axis Y have a second included angle β, so that the entire architecture of the DLP projection module presents a gun-shaped arrangement. The gun-shaped architecture of the DLP projection module makes full use of space, making the light source module 1, the relay lens module 3 and the projection lens 5 compactly arranged to meet the requirements of miniaturization design. The rotation during light transmission is achieved by the tilted arrangement of sub-lenses 21 on the surface of the compound eye lens 2. Combined with the DMD chip 4 and projection lens 5, which are angled to the light source's optical axis X, this ensures that the gun-type DLP projection module does not excessively lose light, maximizing optical utilization while reducing the overall cost of the projection module. Preferably, both the first angle α and the second angle β are 50°, ensuring a reasonable arrangement of the light source module 1 and the projection lens 5. This allows for significant control over the extension length of the projection lens 5 along the light source's optical axis X and its width in the direction perpendicular to the X, satisfying the requirements of miniaturization while maintaining high light utilization.

[0027] Multiple sub-lenses 21, which are microlens arrays of the compound eye lens 2, are disposed on the surface of the compound eye lens 2. The projection shape of the sub-lenses 21 on the surface of the compound eye lens 2 is rectangular, but the optical surface of the sub-lenses 21 can be spherical. The compound eye lens 2 mainly segments the received light, that is, it segments the light spot formed by the light, which is equivalent to dividing a large-aperture light spot into several small-aperture light spots. Each small-aperture light spot is compressed at an angle by the sub-lenses 21 and then unfolded by the relay lens module 3 and transmitted to the DMD chip 4. The light spot on the DMD chip 4 is the result of several small-aperture light spots unfolded and then superimposed. The uniformity of the light spot entering the surface of the DMD chip 4 depends on each small-aperture light spot, and the uniformity of the small-aperture light spot is much better than the uniformity of the large-aperture light spot before it is segmented. That is, the compound eye lens 2 mainly homogenizes the passing light, thereby ensuring the projection quality of the DLP projection module with the gun-shaped architecture.

[0028] In one embodiment, the light source module 1 includes three corresponding light sources 11, three collimating lens assemblies 12, and three reflectors 13, that is, each light source 11 corresponds to one collimating lens assembly 12 and one reflector 13. The light emitted by the light source 11 is directed to the reflector 13 through the collimating lens assembly 12, and after being reflected by the reflector 13, it propagates along the X direction of the light source optical axis. Along the optical axis X of the light source and towards the compound eye lens 2, three light sources 11 are arranged sequentially as a blue light source 111, a green light source 112, and a red light source 113. Correspondingly, three reflectors 13 are arranged sequentially as a blue reflector 131, a green dichroic mirror 132, and a red dichroic mirror 133. That is, the reflector 13 corresponding to the blue light source 111 is a blue reflector 131, the reflector 13 corresponding to the green light source 112 is a green dichroic mirror 132, and the reflector 13 corresponding to the red light source 113 is a red dichroic mirror 133. The red light source 113 is closest to the compound eye lens 2 along the optical axis X. The blue reflector 131, the green dichroic mirror 132, and the red dichroic mirror 133 work together to redirect and converge the blue, green, and red light rays. Specifically, the direction in which the light source shines onto the collimating lens assembly 12 is perpendicular to the light source's optical axis X. The reflector 13 is located on the light-emitting side of the collimating lens assembly 12 and is positioned on the light source's optical axis X. The light source module 1 is designed to consist of a blue light source 111, a green light source 112, and a red light source 113, enabling the light source module 1 to project light of more colors and improve the color saturation of the DLP projection module. Preferably, the light source 11, the collimating lens assembly 12, and the reflector 13 are arranged along a first direction, which is perpendicular to both the light source's optical axis X and the projection optical axis Y.

[0029] It should be noted that the blue light reflector 131 reflects blue light rays incident on its front side. The green light dichroic mirror 132 reflects green light rays incident on its front side and allows blue light rays incident on its back side to pass through, thus converging the blue and green light rays. The red light dichroic mirror 133 reflects red light rays incident on its front side and allows blue and green light rays incident on its back side to pass through, thus converging and integrating the blue, green, and red light rays. That is, the blue light reflector 131 is a total internal reflection reflector, while the green light dichroic mirror 132 and the red light dichroic mirror 133 are selective reflection reflectors.

[0030] In some embodiments, the collimating lens assembly 12 includes a first collimating lens 121 and a second collimating lens 122. The first collimating lens 121 is located near the light source 11, and the combined focal length of the first collimating lens 121 and the second collimating lens 122 is 6.56 mm to 7.06 mm. Preferably, the first collimating lens 121 is a glass spherical lens with a refractive index Nd between 1.75 and 1.85, a dispersion coefficient Vd greater than 40, and a focal length of 9.97 mm to 10.97 mm, ensuring that the first collimating lens 121 has high light-gathering ability and can gather more light from the light source. The second collimating lens 122 is a plastic aspherical lens with a refractive index Nd between 1.5 and 1.6, a dispersion coefficient Vd greater than 50, and a focal length of 11.4 mm to 12.4 mm. Furthermore, the ratio of the center thickness to the edge thickness of the second collimating lens 122 is less than 3, ensuring that the second collimating lens 122 has strong light-gathering ability while reducing costs and manufacturing difficulty. Furthermore, the combined focal length limitation of the first collimating lens 121 and the second collimating lens 122 ensures that the light emitted by the light source 11 can completely illuminate the front of the reflector 13 after passing through the collimating lens assembly 12, thereby improving the utilization rate of light.

[0031] In some embodiments, the blue reflector 131, the green dichroic mirror 132, and the red dichroic mirror 133 are all placed at a 45° angle to the optical axis X of the light source. This ensures that the green and red dichroic mirrors 132 and 133 can reflect the light from the collimating lens assembly 12 and transmit it along the optical axis X of the light source while avoiding light loss. A collimation compensation lens 14 is disposed between the green and red dichroic mirrors 132 and 133. The focal length of the collimation compensation lens 14 is 75mm to 105mm. The collimation compensation lens 14 mainly collimates and corrects the blue and green light rays to ensure the collimation of the light emitted from the light source module 1. It is understood that the collimation compensation lens 14 is disposed between the green and red dichroic mirrors 132 and on the optical axis X of the light source.

[0032] In some embodiments, the collimation compensation lens 14 is a plano-convex cylindrical lens, comprising two parallel cut surfaces, wherein the angle between the cut surfaces and the bottom edge of the compound eye lens 2 is 50°±15°. It should be noted that a cylindrical lens is formed by removing the two sides of a cylindrical lens along one diameter, resulting in two parallel cut surfaces. Cylindrical lenses exhibit strong directional optical characteristics. The angle between the cut surfaces of the collimation compensation lens 14 and the bottom edge of the compound eye lens 2 is 50°±15°, meaning the cut surfaces of the cylindrical lens are rotated 50° around the optical axis X of the light source, allowing for an error range of ±15°, i.e., an actual adjustable range of 35°. ～ 65°. By rotating and adjusting the optical direction of the collimation compensation lens 14, it can be adapted to the tilted sub-lens 21 on the surface of the compound eye lens 2, thus ensuring that the light from the light source module 1 can be adapted to the compound eye lens 2.

[0033] In some embodiments, the compound eye lens 2 includes a first surface 23 facing the light source module 1 and a second surface 24 facing away from the first surface 23. A sub-lens 21 is disposed on the second surface 24. The distance between the first surface 23 and the second surface 24 on the optical axis X of the light source is 8mm to 13mm, and the sagitta of the sub-lens 21 is 0.1mm to 0.2mm, ensuring that the compound eye lens 2 meets the requirements of miniaturization while having excellent optical performance. It should be noted that the distance between the first surface 23 and the second surface 24 is also the thickness of the first surface 23 and the second surface 24 in the direction of the optical axis X of the light source.

[0034] In some embodiments, the relay lens module 3 includes a first relay lens 31, a first reflector 32, a second relay lens 33, and a right-angle prism 34 arranged sequentially. The first relay lens 31 is disposed along the optical axis X of the light source on the light-emitting side of the compound eye lens 2, and is used to receive light from the compound eye lens 2. The first reflector 32 is disposed on the light-emitting side of the first relay lens 31, and the first reflector 32 has a reflective surface 321, which is arranged at a 45° angle to the optical axis X of the light source. The reflective surface 321 is used to redirect the light from the first relay lens 31, that is, the reflective surface 321 redirects the light propagating along the optical axis X of the light source to propagate in a direction perpendicular to the optical axis X of the light source. The second relay lens 33 is disposed towards the reflective surface 321 and receives the light reflected by the reflective surface 321. The right-angle prism 34 is disposed on the light-emitting side of the second relay lens 33 and receives the light from the second relay lens 33. The first relay lens 31 and the second relay lens 33 are located on different planes, but both the first relay lens 31 and the second relay lens 33 face the reflective surface 321 of the first reflector 32.

[0035] In some embodiments, the right-angle prism 34 is made of glass, and the refractive index Nd of the right-angle prism 34 is 1.60 to 1.65, and its dispersion coefficient Vd is greater than 30, ensuring that light enters the right-angle prism 34 and undergoes total internal reflection on its inclined surface, thereby improving the light reflection efficiency and reducing stray light.

[0036] In some embodiments, such as Figure 1 As shown, the right-angle prism 34 includes a first light-incident surface 341, a first light-exiting surface 342, and a second light-exiting surface 343. The first light-incident surface 341 forms an angle with the first light-exiting surface 342 and the second light-exiting surface 343, and the first light-exiting surface 342 and the second light-exiting surface 343 are arranged perpendicularly. That is, the first light-exiting surface 342 and the second light-exiting surface 343 are the two right-angled surfaces of the right-angle prism 34, and the first light-incident surface 341 is the inclined surface of the right-angle prism 34. The first light-incident surface 341 is located on the light-exiting side of the second relay lens 33, the DMD chip 4 faces the first light-exiting surface 342, and the projection lens 5 faces the second light-exiting surface 343. The light emitted from the second relay lens 33 enters the right-angle prism 34 through the first light-incident surface 341, exits the right-angle prism 34 through the first light-outcanceling surface 342, and enters the DMD chip 4. The DMD chip 4 converts the light into image light with image information and reflects the image light back to the first light-outcanceling surface 342. The image light re-enters the right-angle prism 34 through the first light-outcanceling surface 342, exits the right-angle prism 34 through the second light-outcanceling surface 343, and finally reaches the projection lens 5. It should be noted that the first light-emitting surface 342 and the second light-emitting surface 343 of the right-angle prism 34 are perpendicular, and the DMD chip 4 faces the first light-emitting surface 342, while the projection lens 5 faces the second light-emitting surface 343. That is to say, the DMD chip 4 and the projection lens 5 are spaced apart along the projection optical axis Y and are located in the same projection optical axis Y. The projection optical axis Y of the projection lens 5 has a second angle b with the light source optical axis X, and the line o connecting the center points of the sub-lenses 21 of the compound eye lens 2 has a first angle a with the bottom edge 22 of the compound eye lens 2. The first angle a is equal to the second angle b. This ensures that the light spot that rotates after passing through the compound eye lens 2 can be adapted to the surface of the DMD chip 4, avoiding the light projected onto the surface of the DMD chip 4 from exceeding the surface of the DMD chip 4 and causing light waste. That is, the design of the first angle a and the second angle b is to ensure that the projection lens 5 and the light source module 1 are angled to meet the requirements of miniaturization and improve the light utilization efficiency.

[0037] In some embodiments, the focal length of the first relay lens 31 is 61mm to 66mm, the focal length of the second relay lens 33 is 33mm to 38mm, and the angle between the optical axis of the second relay lens 33 and the optical axis X of the light source is 40° to 50°. This ensures that the relay lens module 3 can relay and homogenize light, better receive light from the compound eye lens 2, and shorten the distance between the first relay lens 31 and the second relay lens 33, meeting the requirements of miniaturization design. It should be noted that the angle between the optical axis of the second relay lens 33 and the optical axis X of the light source is 40° to 50°, ensuring that the second relay lens 33 can better match the first light-incident surface 341 of the right-angle prism 34, that is, ensuring that the light-out surface of the second relay lens 33 is similarly parallel to the first light-incident surface 341, improving the light transmission efficiency. Furthermore, the distance between the center point of the compound eye lens 2 and the center point of the first relay lens 31 on the optical axis X of the light source is greater than 1.5 mm, and the distance between the center point of the first relay lens 31 and the center point of the first reflector 32 on the optical axis X of the light source is greater than 12.5 mm. This ensures that the first relay lens 31 can better receive light from the compound eye lens 2, and the second relay lens 33 can better receive light from the first relay lens 31, thereby improving the light transmission efficiency of the relay lens module 3.

[0038] In some embodiments, the total length of the projection lens 5 is 53mm to 57mm, and the effective focal length of the projection lens 5 is 18mm to 21mm, which meets the requirements of miniaturization design and ensures the quality of the projected image.

[0039] Preferably, the projection lens 5 consists of six spherical glass lenses, with the diameter of the first lens less than 23mm, the diameter of the sixth lens less than 19mm, and the entrance diameter of the projection lens 5 being 7.5mm to 8.1mm, meeting the requirements of miniaturization design. Furthermore, the aperture value of the projection lens 5 is F-value 2.0 to 2.6, ensuring clear imaging. The ratio of the projection distance of the projection lens 5 to the long side of the projected image is 1.62:1, and the ratio of the long side to the short side of the projected image is 2:1, ensuring that the image projected by the projection lens 5 is clearly visible.

[0040] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concept, should be covered within the scope of protection of the present invention.

Claims

1. A gun-shaped DLP projection module, characterized in that, include: A light source module, wherein the light source module has a light source optical axis, and the light source module is used to emit light rays that travel along the light source optical axis; A compound eye lens is disposed on the light-emitting side of the light source module. The compound eye lens has a rectangular shape and a plurality of sub-lenses are disposed on the surface of the compound eye lens. The sub-lenses are arranged in an array and the line connecting the center points of the sub-lenses forms a first angle with the bottom edge of the compound eye lens. A relay lens module is disposed on the light-emitting side of the compound eye lens for receiving light from the compound eye lens and redirecting the light, wherein the relay lens module has two light-emitting sides; A DMD chip is disposed on one of the light-emitting sides of the relay lens module, for receiving light from the relay lens module and converting the light into image light and sending it back to the relay lens module; A projection lens is disposed on another light-emitting side of the relay lens module. The projection lens has a projection optical axis that is parallel to the light source optical axis. The angle between the projection optical axis and the light source optical axis on the same plane is a second angle. The projection lens is used to receive image light that has been deflected by the relay lens module. Wherein, the first included angle and the second included angle have the same value, and the range of the first included angle and the second included angle is 40° to 80°.

2. The DLP projection module with a gun-shaped architecture according to claim 1, characterized in that, The light source module includes three corresponding light sources, three collimating lens assemblies, and three reflectors. The light emitted by the light source is directed to the reflector through the collimating lens assembly and then reflected by the reflector before propagating along the optical axis of the light source. Along the optical axis of the light source and in the direction of the compound eye lens, the three light sources are arranged in sequence as a blue light source, a green light source and a red light source, and the three corresponding reflectors are arranged in sequence as a blue reflector, a green dichroic mirror and a red dichroic mirror.

3. The DLP projection module with a gun-shaped architecture according to claim 2, characterized in that, The collimating lens assembly includes a first collimating lens and a second collimating lens. The first collimating lens is close to the light source, and the combined focal length of the first collimating lens and the second collimating lens is 6.56mm to 7.06mm.

4. The DLP projection module with a gun-shaped architecture according to claim 3, characterized in that, The blue light reflector, the green light dichroic mirror, and the red light dichroic mirror are all placed at a 45° angle to the optical axis of the light source, and a collimation compensation lens is provided between the green light dichroic mirror and the red light dichroic mirror. The focal length of the collimation compensation lens is 75mm to 105mm.

5. The DLP projection module with a gun-shaped architecture according to claim 4, characterized in that, The collimation compensation lens is a plano-convex cylindrical lens, and the collimation compensation lens includes two parallel cut surfaces, the angle between the cut surfaces and the bottom edge of the compound eye lens is 50°±15°.

6. The DLP projection module with a gun-shaped architecture according to claim 1, characterized in that, The compound eye lens includes a first surface facing the light source module and a second surface facing away from the first surface. The sub-lens is disposed on the second surface. The distance between the first surface and the second surface on the optical axis of the light source is 8mm to 13mm, and the sagitta of the sub-lens is 0.1mm to 0.2mm.

7. The DLP projection module with a gun-shaped architecture according to claim 1, characterized in that, The relay lens module includes a first relay lens, a first reflector, a second relay lens, and a right-angle prism arranged sequentially. The first relay lens is arranged along the optical axis of the light source on the light-emitting side of the compound eye lens. The first reflector is arranged on the light-emitting side of the first relay lens. The first reflector has a reflective surface, and the reflective surface is arranged at a 45° angle to the optical axis of the light source. The second relay lens is arranged facing the reflective surface. The right-angle prism is arranged on the light-emitting side of the second relay lens. The right-angle prism is made of glass, and its refractive index Nd is 1.60 to 1.65, and its dispersion coefficient Vd is greater than 30.

8. The DLP projection module with a gun-shaped architecture according to claim 7, characterized in that, The right-angle prism includes a first light-incident surface, a first light-exiting surface, and a second light-exiting surface. The first light-incident surface forms an angle with the first light-exiting surface and the second light-exiting surface, and the first light-exiting surface and the second light-exiting surface are arranged perpendicularly. The first light-incident surface is located on the light-exiting side of the second relay lens. The DMD chip faces the first light-exiting surface, and the projection lens faces the second light-exiting surface.

9. The DLP projection module with a gun-shaped architecture according to claim 8, characterized in that, The focal length of the first relay lens is 61mm to 66mm, the focal length of the second relay lens is 33mm to 38mm, and the angle between the optical axis of the second relay lens and the optical axis of the light source is 40° to 50°. The distance between the center point of the compound eye lens and the center point of the first relay lens on the optical axis of the light source is greater than 1.5 mm, and the distance between the center point of the first relay lens and the center point of the first reflector on the optical axis of the light source is greater than 12.5 mm.

10. The DLP projection module with a gun-shaped architecture according to claim 1, characterized in that, The total length of the projection lens is 53mm to 57mm, and the effective focal length of the projection lens is 18mm to 21mm.

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