Illumination system and projection device

Abstract

The invention provides an illumination system and a projection device comprising the illumination system. The lighting system comprises a light source, a first turning prism, a second turning prism and a dodging element. The light source emits a light beam. The first turning prism is arranged on an advancing path of the light beam. The second turning prism is arranged on the advancing path of the light beam from the first turning prism, and the first turning prism and the second turning prism guide the light beam together. The light uniformizing element is arranged between the first turning prism and the second turning prism and is used for carrying out light uniformizing treatment on the light beams. Through the configuration of the first turning prism, the second turning prism and the dodging element, the light path is shortened, and the uniformity of the light beam is ensured. Based on the advantages of the lighting system, the projection device achieves the purpose of reducing the size of the miniature projector.

Description

Technical Field

[0001] The present application relates to the field of optical projection technology, and in particular to an illumination system and a projection device. Background Art

[0002] With the development of solid-state light sources and projection technology, projectors can be seen everywhere in our daily lives. In order to meet the demand for thinner and lighter electronic products, projectors have begun to move towards miniaturization, and the number of micro projectors is increasing.

[0003] Most existing micro-projectors use multiple lenses and reflectors to guide the projection light path. However, because each lens has different optical properties, a specific spacing must be set between adjacent lenses based on their optical properties. A specific spacing must also be set between the reflector and its adjacent lens, and the specific spacing corresponding to each lens varies. This specific spacing between the multiple lenses and reflectors results in a micro-projector that is too large and highly susceptible to assembly errors. Furthermore, the multiple lenses increase the manufacturing cost of the micro-projector.

[0004] The "Prior Art" section is intended only to facilitate understanding of the present invention. Therefore, the information disclosed in this section may contain information that is not generally known to those skilled in the art. The information disclosed in this section does not imply that the information or the problems to be solved by one or more embodiments of the present invention were known or understood by those skilled in the art before the filing of this application. Summary of the Invention

[0005] Based on the foregoing, the present application provides a lighting system and a projection device, which can achieve the purpose of reducing the size of a micro projector and reducing the assembly error of the micro projector.

[0006] Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the present invention.

[0007] To achieve one, some, or all of the above objectives, or other objectives, an illumination system according to one embodiment of the present invention includes a light source, a first turning prism, a second turning prism, and a light homogenizing element. The light source emits a light beam. The first turning prism is disposed in the path of the light beam. The second turning prism is disposed in the path of the light beam from the first turning prism. The first and second turning prisms jointly guide the light beam. The light homogenizing element is disposed between the first and second turning prisms and homogenizes the light beam.

[0008] To achieve one, part, or all of the above-mentioned purposes or other purposes, a projection device according to one embodiment of the present invention includes an illumination system, a total reflection prism, a light valve, and a projection lens. The illumination system includes a light source, a first turning prism, and a second turning prism. The light source emits a light beam. The first turning prism is arranged on the path of the light beam. The second turning prism is arranged on the path of the light beam from the first turning prism, and the first turning prism and the second turning prism jointly guide the light beam. The light homogenizing element is arranged between the first turning prism and the second turning prism, and performs light homogenization processing on the light beam. The total reflection prism is arranged on the path of the light beam from the second turning prism, and forms an illumination light beam. The light valve is arranged on the path of the illumination light beam, and converts the illumination light beam into an image light beam. The projection lens is arranged on the path of the image light beam.

[0009] In summary, the lighting system of the present application utilizes two turning prisms to guide the light beam and is equipped with a light homogenizing element to homogenize the light beam, thereby shortening the optical path and ensuring the uniformity of the light beam.

[0010] In summary, the projection device of the present application achieves the goal of reducing the size of the micro-projector through the configuration of the aforementioned illumination system. Furthermore, since two deflection prisms replace the combination of multiple lenses and reflectors, the number of lenses used can be reduced, thereby achieving the goal of reducing the manufacturing cost and assembly error of the micro-projector. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 FIG. 1 is a configuration diagram of a lighting system according to an embodiment of the present application.

[0012] Figure 2 FIG1 is a configuration diagram of a projection device according to an embodiment of the present application.

[0013] Figure 3 FIG. 4 is a configuration diagram of a projection device according to another embodiment of the present application.

[0014] Description of reference numerals:

[0015] 1A, 1B: Lighting system

[0016] 10: Light Source

[0017] 20: First Turn Prism

[0018] 30: Light homogenization element

[0019] 40: Second Turning Prism

[0020] 50: Light valve

[0021] 60: Total reflection prism

[0022] 61: First auxiliary prism

[0023] 62: Second auxiliary prism

[0024] 63: Adhesive layer

[0025] 70: Projection lens

[0026] A1: Prism glue

[0027] IF1: First light incident surface

[0028] IF2: Second light incident surface,

[0029] L1: Beam

[0030] OF1: First light-emitting surface

[0031] OF2: Second light-emitting surface

[0032] RF1: First reflecting surface

[0033] RF2: Second reflective surface

[0034] WF1: First working surface

[0035] WF2: Second working surface

[0036] WF3: Third working surface

[0037] WF4: fourth working surface

[0038] WF5: Fifth working surface DETAILED DESCRIPTION

[0039] The aforementioned technical contents, features, and functions of the present invention will be more clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. Directional terms such as "up," "down," "left," "right," "front," and "rear" mentioned in the following embodiments are merely references to the directions in the accompanying drawings. Therefore, the directional terms used are for illustrative purposes only and are not intended to limit the present application.

[0040] See also Figure 1 , which is a configuration diagram of a lighting system according to an embodiment of the present application. Figure 1 As shown, an illumination system 1A includes a light source 10, a first turning prism 20, a second turning prism 40, and a light homogenizing element 30. The light source 10 emits a light beam L1. The first turning prism 20 is positioned in the path of light beam L1. The second turning prism 40 is positioned in the path of light beam L1 from the first turning prism 20. The first and second turning prisms 20 and 40 jointly guide light beam L1. The light homogenizing element 30 is positioned between the first and second turning prisms 20 and 40 to homogenize light beam L1.

[0041] The light source 10 is a solid-state light source. For example, the light source 10 can be a light emitting diode (LED) or a laser diode. In this embodiment, the light source 10 can emit multiple light beams of different colors, that is, the light beam comprises multiple light beams of different colors. Specifically, the light source 10 includes a first light-emitting unit, a second light-emitting unit, and a third light-emitting unit. The light colors emitted by the first light-emitting unit, the second light-emitting unit, and the third light-emitting unit are different. For example, the first light-emitting unit is a red light-emitting diode (LED), the second light-emitting unit is a green light-emitting diode (LED), and the third light-emitting unit is a blue light-emitting diode (LED). The first light-emitting unit emits a first light beam at a first clock frequency, the second light-emitting unit emits a second light beam at a second clock frequency, and the third light-emitting unit emits a third light beam at a third clock frequency. The first, second, and third clock frequencies are different from each other. Therefore, the emission times of the first light beam, the second light beam, and the third light beam are different from each other. The first, second, and third light beams are emitted in sequence and at intervals to form the light beam L1. In other words, the first light-emitting unit, the second light beam, and the third light beam emit light at intervals according to their corresponding clock frequencies to form the light beam.

[0042] The first turning prism 20 is disposed between the light source 10 and the light homogenizing element 30, and is spaced apart from the light source 10 and the light homogenizing element 30, respectively. The material of the first turning prism 20 may include N-BK7 or fused quartz. Furthermore, the first turning prism 20 includes a first light incident surface IF1, a first light exiting surface OF1, and a first reflecting surface RF1; the first reflecting surface RF1 and the first light exiting surface OF1 are located on the side of the first light incident surface IF1 facing away from the light source 10. The first light incident surface IF1 faces the light source 10, and the first light incident surface IF1 is perpendicular to the direction of travel of the light beam L1. The first light incident surface IF1 is a plane. In another embodiment, the first light incident surface IF1 is a spherical surface or a free-form surface. The first reflecting surface RF1 is a spherical reflector having a metal layer. In another embodiment, the first reflecting surface RF1 is a curved surface or a free-form surface having a metal layer. The material of the metal layer may, for example, include aluminum (Al), silver (Ag), or gold (Au). The first light emitting surface OF1 faces the light homogenizing element 30 and is a plane. In another embodiment, the first light emitting surface OF1 may also be a spherical surface or a free-form surface.

[0043] The path of the light beam L1 in the first turning prism 20 is as follows: the light beam L1 is incident from the first light incident surface IF1 to the first light output surface OF1, the first light output surface OF1 reflects the light beam L1 and guides the light beam L1 to the first reflection surface RF1, the first reflection surface RF1 reflects the light beam L1 and guides the light beam L1 to pass through the first light output surface OF1 and be incident on the light homogenizing element 30.

[0044] The light homogenizing element 30 is located in the path of the light beam L1 from the first turning prism 20. One side of the light homogenizing element 30 faces the first turning prism 20, and the other side of the light homogenizing element 30, facing away from the first turning prism 20, faces the second turning prism 40. For example, the light homogenizing element 30 can be an integrating rod or a lens array. The light homogenizing element 30 is arranged parallel to the first light output surface OF1. The light homogenizing element 30 receives the light beam L1 from the first turning prism 20 and homogenizes the light beam L1 to achieve a uniform light intensity distribution. The light homogenizing element 30 then directs the homogenized light beam to the second turning prism 40.

[0045] The second turning prism 40 is located in the path of the light beam L1 from the light homogenizing element 30. The second turning prism 40 is spaced apart from the light homogenizing element 30 and may be made of N-BK7 or fused silica. Specifically, the second turning prism 40 includes a second light incident surface IF2, a second light exit surface OF2, and a second reflective surface RF2. The second reflective surface RF2 and the second light exit surface OF2 are located on the side of the second light incident surface IF2 facing away from the light homogenizing element 30. The second light incident surface IF2 faces the light homogenizing element 30 and is arranged parallel to the light homogenizing element 30. In this embodiment, the second light incident surface IF2 is a plane; in another embodiment, the second light incident surface IF2 is a spherical surface or a free-form surface. The second reflective surface RF2 is a spherical reflector with a metal layer; in another embodiment, the second reflective surface RF2 is a curved surface or a free-form surface with a metal layer. The second light exit surface OF2 is a plane; in another embodiment, the second light exit surface OF2 is a spherical surface or a free-form surface.

[0046] The path of the light beam L1 in the second turning prism 40 is as follows: the light beam L1 from the light homogenizing element 30 is incident on the second light-emitting surface OF2 from the second light-incident surface IF2, the second light-emitting surface OF2 reflects the light beam L1 from the light homogenizing element 30 and guides the light beam L1 from the light homogenizing element 30 to the second reflecting surface RF2, and the second reflecting surface RF2 reflects the light beam L1 from the light homogenizing element 30 and guides the light beam L1 from the light homogenizing element 30 to pass through the second light-emitting surface OF2.

[0047] The paths of the integrated light beam L1 through the first turning prism 20 and the second turning prism 40 are further described, and the optical path of the light beam L1 through the illumination system 1A is further described as follows: Light beam L1 is perpendicularly incident from the first light-incident surface IF1 into the interior of the first turning prism 20 and travels to the first light-exiting surface OF1. The incident angle of light beam L1 on the first light-exiting surface OF1 satisfies the critical angle condition for total internal reflection of the first turning prism 20, and total internal reflection occurs at the first light-exiting surface OF1, forming first incident light. The first incident light then enters the first reflecting surface RF. Due to the metal layer on the first reflecting surface RF1, the first incident light is reflected from the first reflecting surface RF1 to form first reflected light, which then enters the light homogenizing element 30. The light homogenizing element 30 performs light homogenization processing on the first reflected light to form first uniform light.

[0048] Next, the first uniform light beam perpendicularly enters the interior of the second turning prism 40 from the second light-incident surface IF2 and travels to the second light-exiting surface OF2. The incident angle of the first uniform light beam on the second light-exiting surface OF2 satisfies the critical angle condition for total internal reflection of the second turning prism 40, and is totally reflected from the second light-exiting surface OF2 to form second incident light beams. The second incident light beams then enter the second reflective surface RF2. Due to the metal layer on the second reflective surface RF2, the second incident light beams are reflected from the second reflective surface RF2 to form second reflected light beams, which then travel through the second light-exiting surface OF2.

[0049] In this embodiment, the illumination system utilizes two deflection prisms for light beam guidance. Because the optical properties of these two deflection prisms differ from those of lenses, the illumination system does not need to consider the focal length, imaging distance, or specific spacing between adjacent lenses. This shortens the optical path and simplifies the configuration of the illumination system. Furthermore, this embodiment can be applied to micro-projectors, further reducing their size.

[0050] See also Figure 2 , which is a configuration diagram of a projection device according to an embodiment of the present application. Figure 2 As shown, the projection device includes an illumination system 1A, a total reflection prism 60, a light valve 50 and a projection lens 70. The illumination system 1A includes a light source 10, a first turning prism 20, a second turning prism 40 and a light homogenizing element 30. The configuration of the light source 10, the first turning prism 20, the second turning prism 40 and the light homogenizing element 30 is similar to that of the projection device 1A. Figure 1 The configuration shown is similar and will not be repeated here.

[0051] The total reflection prism 60 is positioned in the path of the light beam L1 from the second turning prism 40 and forms an illumination beam. Specifically, the total reflection prism 60 is positioned between the light valve 50 and the projection lens 70, while the second turning prism 40 is positioned between the total reflection prism 60 and the light homogenizing element 30. The total reflection prism 60 receives the light beam L1 from the second turning prism 40 and forms and guides the illumination beam toward the light valve 50. Furthermore, the total reflection prism 60 includes a first auxiliary prism 61, a second auxiliary prism 62, and an adhesive layer 63. The first auxiliary prism 61 is bonded to the second auxiliary prism 62 via the adhesive layer 63. The adhesive layer 63 can be made of Canada rubber, prism adhesive, or UV adhesive.

[0052] The first auxiliary prism 61 has a first working surface WF1, a second working surface WF2, and a third working surface WF3. The second working surface WF2 and the third working surface WF3 are arranged on the side of the first working surface WF1 facing away from the second turning prism 40. The first working surface WF1 faces the second light-emitting surface OF2 of the second turning prism 40 and is arranged parallel to the second light-emitting surface OF2. The second working surface WF2 is the bonding surface in contact with the adhesive layer 63. That is, the second working surface WF2 partially overlaps with the adhesive layer 63, and the portion of the second working surface WF2 not overlapping with the adhesive layer 63 is exposed to the air. The third working surface WF3 faces the light valve 50 and is arranged parallel to the light valve 50. The first working surface WF1, the second working surface WF2, and the third working surface WF3 are all planar.

[0053] The second auxiliary prism 62 has a fourth working surface WF4 and a fifth working surface WF5. The fourth working surface WF4 is located on the side of the fifth working surface WF5 facing away from the projection lens 70. The fourth working surface WF4 is the bonding surface in contact with the adhesive layer 63. Specifically, the fourth working surface WF4 partially overlaps with the second working surface WF2, and the portion of the fourth working surface WF4 not overlapping with the adhesive layer 63 is exposed to air. The fifth working surface WF5 faces the projection lens 70 and is disposed parallel to the projection lens 70. Both the fourth working surface WF4 and the fifth working surface WF5 are planar.

[0054] The path of the light beam L1 in the total reflection prism 60 is as follows: the light beam L1 from the second turning prism is incident from the first working surface WF1 to the second working surface WF2, the second working surface WF2 reflects the light beam L1 to form an illumination beam, and the illumination beam passes through the third working surface WF3 and is incident on the light valve 50.

[0055] The light valve 50 is positioned in the path of the illumination beam and converts it into an image beam. The image beam then passes through a total reflection prism 60 and enters the projection lens 70. For example, the light valve 50 is a digital micromirror device (DMD). Specifically, the light valve 50 receives the illumination beam from the second working surface WF2 and converts it into an image beam using multiple micro-mirrors on the DMD. The projection lens 70 is positioned in the path of the image beam and receives the image beam from the total reflection prism 60. It then appropriately adjusts the image beam and projects it onto the screen.

[0056] See again Figure 1 , according to the corresponding Figure 1 The light beam L1 derived from the second light-emitting surface OF2 of the second turning prism 40 is the second reflected light. Figure 2 The light transmission path between the total reflection prism 60, the light valve 50, and the projection lens 70 is described as follows: The second reflected light is incident from the first working surface WF1 onto the second working surface WF2. The incident angle of the second reflected light on the second working surface WF2 meets the critical angle condition for total reflection of the first auxiliary prism 61. The second reflected light is totally reflected at the second working surface WF2 to form an illumination beam. The illumination beam passes through the third working surface WF3 and enters the light valve 50. The light valve 50 generates an image beam based on the illumination beam. The image beam is perpendicularly incident from the third working surface WF3 into the interior of the first auxiliary prism 61, passes through the second working surface WF2, the adhesive layer 63, and the fourth working surface WF4. The image beam is then incident on the second auxiliary prism 62 and passes through the fifth working surface WF5 to reach the projection lens 70.

[0057] The projection device of this embodiment has the advantages of an illumination system while achieving the goal of reducing the size of a micro-projector. Furthermore, since two deflection prisms replace multiple lens and reflector combinations, the number of lenses and reflectors can be reduced, thereby reducing the manufacturing cost and assembly error of the micro-projector.

[0058] See also Figure 3 , which is a configuration diagram of a projection device according to another embodiment of the present application. Figure 3 As shown, the projection device includes an illumination system 1B, a total reflection prism 60, a light valve 50 and a projection lens 70. The illumination system 1B includes a light source 10, a first turning prism 20, a second turning prism 40 and a light homogenizing element 30. The light source 10, the first turning prism 20, the second turning prism 40 and the light homogenizing element 30 are connected to the projection lens 70. Figure 1The configuration shown is similar, and the similarities between the illumination system 1B and the illumination system 1A will not be repeated. However, the differences between the illumination system 1B and the illumination system 1A are as follows: the first light incident surface IF1 is a spherical surface, the first light exit surface OF1 is a free-form surface, and the second turning prism 40 is bonded to the total reflection prism 60. In addition, the configuration of the total reflection prism 60, the light valve 50, and the projection lens 70 has been described in the corresponding FIG. Figure 2 The description is in the paragraph and will not be repeated here.

[0059] The first light-incident surface IF1, which is a spherical surface, facilitates focusing of the light beam L1 on the first light-outgoing surface OF1. The first light-outgoing surface OF1, which is a free-form surface, improves optical aberrations (such as spherical aberration or optical distortion). The second light-outgoing surface OF2 of the second turning prism 40 and the first working surface WF1 of the first auxiliary prism 61 of the total reflection prism 60 are bonded to each other through prism glue A1. The second light-outgoing surface OF2 and the first working surface WF1 are both planes, making the bonding between the second turning prism 40 and the first auxiliary prism 61 smoother. Due to the bonding between the second turning prism 40 and the first auxiliary prism 61, the light beam L1 derived from the second light-outgoing surface OF2 directly passes through the prism glue and enters the interior of the total reflection prism 60 without passing through air, thereby further shortening the light transmission path between the second turning prism 40 and the total reflection prism 60.

[0060] In the projection device of this embodiment, the second turning prism is bonded to the total internal reflection prism. Both the second turning prism and the total internal reflection prism guide the light beam through total internal reflection, effectively shortening the optical path of the light beam in air and significantly reducing the size of the projection device. If improvements are made to the structure and heat dissipation module of the projection device of this embodiment, the size of the projection device can be further reduced, thereby achieving the goal of optimizing the size of a micro projector.

[0061] In summary, the lighting system of the present application utilizes two turning prisms to guide the light beam and is equipped with a light homogenizing element to homogenize the light beam, thereby shortening the optical path and ensuring the uniformity of the light beam.

[0062] In summary, the projection device of the present application achieves the goal of reducing the size of the micro-projector through the configuration of the aforementioned illumination system. Furthermore, since two turning prisms replace multiple lenses and reflectors, the number of lenses used can be reduced, thereby achieving the goal of reducing the manufacturing cost and assembly error of the micro-projector.

[0063] However, what is described above is only a preferred embodiment of the present invention, and it should not be used to limit the scope of implementation of the present invention. That is, simple equivalent changes and modifications made according to the scope of the present invention and the content of the invention description are still within the scope of the present invention. In addition, any embodiment or patent application of the present invention does not need to achieve all the purposes, advantages or features disclosed by the present invention. In addition, the abstract and title are only used to assist in searching patent documents, and are not used to limit the scope of rights of the present invention. In addition, the terms "first", "second", etc. mentioned in this specification or patent application are only used to name the name of the element or to distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements.

Claims

1. A lighting system, characterized in that: include: a light source, emitting a light beam; a first turning prism, disposed on the path of the light beam; a second turning prism disposed on a path of the light beam from the first turning prism, the first turning prism and the second turning prism jointly guiding the light beam; and The light homogenizing element is disposed between the first turning prism and the second turning prism and performs light homogenization processing on the light beam.

2. The lighting system according to claim 1, wherein The first turning prism includes a first light incident surface, a first light emitting surface and a first reflecting surface. The first reflecting surface and the first light emitting surface are located on the side of the first light incident surface facing away from the light source. The first light incident surface faces the light source and is a spherical surface. The first light emitting surface faces the light homogenizing element and is a plane, a spherical surface or a free-form surface.

3. The lighting system according to claim 2, wherein The light beam is incident from the first light incident surface to the first light emitting surface. The first light emitting surface guides the light beam to the first reflecting surface. The first reflecting surface guides the light beam to pass through the first light emitting surface and be incident on the light homogenizing element.

4. The lighting system according to claim 1, wherein The second turning prism includes a second light incident surface, a second light emitting surface and a second reflecting surface. The second reflecting surface and the second light emitting surface are located on the side of the second light incident surface facing away from the light homogenizing element. The second light incident surface faces the light homogenizing element and is a free-form surface.

5. The lighting system according to claim 4, wherein The light beam from the light homogenizing element is incident from the second light incident surface to the second light emitting surface, the second light emitting surface guides the light beam from the light homogenizing element to the second reflecting surface, and the second reflecting surface guides the light beam from the light homogenizing element to pass through the second light emitting surface.

6. The lighting system according to claim 1, wherein The light source includes a first light emitting unit, a second light emitting unit, and a third light emitting unit. The first light emitting unit, the second light emitting unit, and the third light emitting unit respectively emit light at intervals according to corresponding clock frequencies to form the light beam.

7. The lighting system according to claim 1, wherein The light homogenizing element is an integrating rod or a lens array.

8. A projection device, characterized in that: include: Lighting system, including: a light source, emitting a light beam; a first turning prism, disposed on the path of the light beam; a second turning prism disposed on a path of the light beam from the first turning prism, the first turning prism and the second turning prism jointly guiding the light beam; and a light homogenizing element, disposed between the first turning prism and the second turning prism, and performing light homogenization processing on the light beam; a total reflection prism disposed on the path of the light beam from the second turning prism and forming an illumination light beam; a light valve disposed on the path of the illumination light beam and converting the illumination light beam into an image light beam; and The projection lens is arranged on the traveling path of the image light beam.

9. The projection device according to claim 8, wherein: The first turning prism includes a first light incident surface, a first light emitting surface, and a first reflecting surface. The first reflecting surface and the first light emitting surface are located on the side of the first light incident surface facing away from the light source. The first light incident surface faces the light source and is a spherical surface. The first light emitting surface faces the light homogenizing element and is a plane, a spherical surface, or a free-form surface.

10. The projection device according to claim 9, wherein: The light beam is incident from the first light incident surface to the first light emitting surface. The first light emitting surface guides the light beam to the first reflecting surface. The first reflecting surface guides the light beam to pass through the first light emitting surface and be incident on the light homogenizing element.

11. The projection device according to claim 8, wherein: The second turning prism includes a second light incident surface, a second light emitting surface and a second reflecting surface. The second reflecting surface and the second light emitting surface are located on the side of the second light incident surface facing away from the light homogenizing element. The second light incident surface faces the light homogenizing element and is a free-form surface. The second light emitting surface faces the total reflection prism.

12. The projection device according to claim 11, wherein: The light beam from the light homogenizing element is incident from the second light incident surface to the second light emitting surface, the second light emitting surface guides the light beam from the light homogenizing element to the second reflecting surface, and the second reflecting surface guides the light beam from the light homogenizing element to pass through the second light emitting surface.

13. The projection device according to claim 8, wherein: The light source includes a first light emitting unit, a second light emitting unit, and a third light emitting unit. The first light emitting unit, the second light emitting unit, and the third light emitting unit emit light at intervals according to their respective corresponding clock frequencies to form the light beam.

14. The projection device according to claim 8, wherein: The light homogenizing element is an integrating rod or a lens array.

15. The projection device according to claim 8, wherein: The second turning prism is bonded to the total reflection prism.

16. The projection device according to claim 8, wherein: The total reflection prism includes a first working surface, a second working surface and a third working surface. The second working surface and the third working surface are arranged on the side of the first working surface facing away from the second turning prism. The first working surface faces the second turning prism, and the third working surface faces the light valve.

17. The projection device according to claim 16, wherein: The light beam from the second turning prism is incident from the first working surface to the second working surface to form the illumination beam, and the illumination beam passes through the third working surface and is incident on the light valve. The light valve converts the illumination beam into the image beam, and the image beam passes through the total reflection prism and is incident on the projection lens.

Images