A projection optical machine and a projector

Abstract

The present invention provides a projection optical machine and a projector, including a receiving space inside a housing. The receiving space has a bottom wall, a first side wall, and a second side wall. The prism assembly includes a first right-angle prism and a second right-angle prism. The first right-angle prism has a first right-angle side with a length of L and a second right-angle side with a length of A. A first positioning point, a second positioning point, and a third positioning point are provided on the first side wall. The distances from the first positioning point and the second positioning point to the right-angle vertex of the first right-angle prism are 3 / 4L - 9 / 10L. The distance from the third positioning point to the right-angle vertex of the first right-angle prism is 1 / 4L - 3 / 5L. The distances from the fourth positioning point and the fifth positioning point provided on the second side wall to the right-angle vertex of the first right-angle prism are 1 / 10A - 1 / 5A. A metal block and a first metal elastic member are accommodated in the receiving space. The first metal elastic member abuts the first right-angle prism against the positioning points. The first projection optical machine provided by the present invention reduces the frictional force required to overcome the movement of the prism assembly, facilitating the free movement of the prism assembly due to thermal expansion and contraction.

Description

Technical Field

[0001] The present invention relates to the field of projection devices, and particularly to a projection optical engine and a projector. Background Art

[0002] The core component of a projector is a projection optical engine, and a prism is one of the important core components in the projection optical engine.

[0003] During the operation of the projection optical engine, the light emitted by the light source enters the prism through the initial incident surface of the prism, is reflected by the prism and processed by the DMD, then the light is transmitted to the prism again, and is transmitted from the exit surface of the prism to the lens.

[0004] In the above process, more heat is generated during the light propagation in the prism, causing the temperature of the prism to rise. Due to thermal expansion and contraction, the prism will move. However, currently, when fixing the prism, silicone columns are used to press tightly between the prism and the optical engine housing. However, due to the large friction force between the prism and the inner side wall of the optical engine housing, and the aging of the silicone columns after long-term use, the movement of the prism caused by thermal expansion and contraction is uncontrollable (poor consistency), resulting in poor imaging consistency of the projection optical engine during use. Summary of the Invention

[0005] Based on the above situation, in order to solve the problems that the friction force between the prism and the inner side wall of the optical engine housing is large, and the aging of the silicone columns after long-term use makes the movement of the prism caused by thermal expansion and contraction uncontrollable, resulting in poor imaging consistency of the projection optical engine, the main object of the present invention is to provide a projection optical engine and a projector in which the movement of the prism is controllable, the friction force is small, and the imaging consistency of the projection optical engine is good.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A projection optical engine includes a housing, a prism assembly, a digital micromirror device, and a lens. The interior of the housing includes a receiving space for accommodating the prism assembly. The receiving space has a bottom wall, a first side wall, and a second side wall. The digital micromirror device and the lens are fixed to the housing and their positions correspond to the first side wall and the second side wall respectively. The prism assembly includes a first right-angle prism and a second right-angle prism. The surface where the hypotenuse of the first right-angle prism is located is fixed to the surface where the hypotenuse of the second right-angle prism is located.

[0008] The first right-angle prism has a first right-angle side parallel to the first side wall with a side length of L, and a second right-angle side parallel to the second side wall with a side length of A.

[0009] The first side wall and the second side wall are perpendicular, and an arc-shaped groove is provided at the junction of the two.

[0010] The three positioning points provided on one side wall are respectively a first positioning point, a second positioning point, and a third positioning point. The first positioning point is located above the second positioning point, and their vertical projections on the bottom wall coincide, and the distance from the right-angle vertex of the first right-angle prism is 3 / 4L - 9 / 10L; the third positioning point has the same distance from the bottom wall as the second positioning point, and the distance from the right-angle vertex of the first right-angle prism is 1 / 4L - 3 / 5L;

[0011] The two positioning points provided on the second side wall are a fourth positioning point and a fifth positioning point. The projections of the fourth positioning point and the fifth positioning point on the bottom wall coincide, and the distance from the right-angle vertex of the first right-angle prism is 1 / 10A - 1 / 5A;

[0012] The receiving space houses a metal block and a first metal elastic member at least partially located in the receiving space. One end of the first metal elastic member is fixed to the housing, and the other end presses the metal block against the right angle of the second right-angle prism, thereby pressing the first right-angle prism against the positioning points on the first side wall and the second side wall; the extension line of the end of the first metal elastic member pressing against the metal block is located between the third positioning point and the fifth positioning point;

[0013] Each of the positioning points is integrally formed with the housing.

[0014] Preferably, the area of the positioning point is 1 - 4 square centimeters; the height of the positioning point is 0.3 - 1 cm.

[0015] Preferably, the projection optical machine further includes a second metal elastic member. The receiving space has a top wall. One end of the second metal elastic member presses against the prism assembly, and the other end is fixed to the top wall;

[0016] A sixth positioning point is provided on the bottom wall. The projection of the second metal elastic member on the bottom wall coincides with the position of the sixth positioning point.

[0017] Preferably, the positioning points on the first side wall and the second side wall are square, the positioning point on the bottom wall is circular, and the area of the square positioning point is more than 1.2 times the area of the circular positioning point.

[0018] Preferably, the sixth positioning point is integrally formed with the optical machine housing.

[0019] Preferably, the sixth positioning point presses against the bottom surface of the first right-angle prism and is located on the vertical bisector of its bottom surface. The vertical bisector passes through the right-angle vertex of the first right-angle prism.

[0020] Preferably, the opening of the arc-shaped groove faces the fourth positioning point and the fifth positioning point.

[0021] Preferably, the right angle of the first right-angled prism is located within the arc-shaped groove and does not contact the inner wall of the arc-shaped groove.

[0022] Preferably, the housing is provided with a mounting hole penetrating the housing. The first metal elastic member passes through the mounting hole and is fixedly connected to the housing, and one end extending into the receiving space abuts against the metal block.

[0023] Preferably, the housing is provided with a light inlet. The metal block includes a first contact portion and a second contact portion, and the first contact portion is closer to the light inlet than the second contact portion.

[0024] The first contact portion and the second contact portion are respectively in contact with the first side surface and the second side surface at the right angle of the second right-angled prism.

[0025] The first contact portion includes two rod-shaped bodies spaced apart in the vertical direction, and the rod-shaped bodies are in contact with the edge of the first side surface.

[0026] The second contact portion is a plate-shaped body, and the plate-shaped body at least covers the middle position of the second side surface.

[0027] Preferably, the surface of the plate-shaped body facing the second side surface is provided with a groove, and the plate-shaped body is adhesively fixed to the second side surface.

[0028] Preferably, the metal block further includes an abutting portion, the abutting portion is fixedly connected to the end of the second contact portion close to the first contact portion, the abutting portion and the second contact portion are arranged at an angle, and there is a notch between the two.

[0029] In order to further solve the above technical problems, the present invention provides a projector, including a housing, and the above-mentioned projection optical machine is accommodated in the housing.

[0030] The beneficial effects of the present invention are as follows: the projection optical machine provided by the present invention has a first positioning point, a second positioning point, a third positioning point, a fourth positioning point and a fifth positioning point integrally formed in the receiving space of the optical machine housing, wherein the first positioning point, the second positioning point and the third positioning point are distributed on the first side wall of the receiving space, the first positioning point is above the second positioning point, the projections of the two on the bottom wall of the receiving space overlap, and the distance from the right-angle vertex of the first right-angle prism is 3 / 4L-9 / 10L, and the third positioning point and the second positioning point have the same distance from the bottom wall. , and the distance between the third positioning point and the right-angle vertex of the first right-angle prism is 1 / 4L-3 / 5L; the fourth positioning point and the fifth positioning point are distributed on the second side wall, the projections of the fourth positioning point and the fifth positioning point on the bottom wall coincide with each other, and the distance between the third positioning point and the right-angle vertex of the first right-angle prism is 1 / 10A-1 / 5A; by setting the positioning points at the above distribution positions, the contact area between the prism assembly and the first side wall and the second side wall can be reduced, so as to reduce the friction force that needs to be overcome when the prism assembly moves, and facilitate the free movement of the prism assembly due to thermal expansion and contraction. A first metal elastic part and a metal block are used to hold the prism assembly against the metal block. The extension line of one end of the first metal elastic part that rests on the metal block is located between the third positioning point and the fifth positioning point. The prism assembly is positioned in conjunction with the above-mentioned positioning points. The first metal elastic part and the metal block, as well as the metal block and the prism assembly are in hard contact. The first metal elastic part and the metal block are not prone to aging, which can ensure that the prism assembly can move freely when heated, while also making the thermal expansion and contraction of the prism assembly controllable and consistent, thereby improving the imaging consistency of the projection optical machine.

[0031] Other beneficial effects of the present invention will be explained in the specific implementation manner through the introduction of specific technical features and technical solutions. Through the introduction of these technical features and technical solutions, those skilled in the art should be able to understand the beneficial technical effects brought about by the technical features and technical solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] A preferred embodiment of a projection optical engine according to the present invention will be described below with reference to the accompanying drawings.

[0033] In the figure:

[0034] Figure 1 A schematic diagram of the three-dimensional structure of a projection optical machine provided by the present invention.

[0035] Figure 2 A projection optical machine provided by the present invention is an exploded schematic diagram showing a DMD.

[0036] Figure 3 A partial structural schematic diagram of a projection optical machine provided by the present invention shows a housing cavity.

[0037] Figure 4The figure is a schematic cross-sectional view showing the top wall of a projection optical machine provided by the present invention.

[0038] Figure 5 The figure is a partial structural schematic view showing the positions of an arc-shaped groove and a first right-angle prism of a projection optical machine provided by the present invention.

[0039] Figure 6 The figure is a structural schematic view of a prism assembly of a projection optical machine provided by the present invention.

[0040] Figure 7 The figure is a structural schematic view of a metal block of a projection optical machine provided by the present invention.

[0041] Description of the drawings: 1. Housing; 11. Accommodating space; 111. Light inlet; 112. Light outlet; 113. Light passing opening; 114. Mounting hole; 115. Arc-shaped groove; 12. Side wall one; 121. First positioning point; 122. Second positioning point; 123. Third positioning point; 13. Side wall two; 131. Fourth positioning point; 132. Fifth positioning point; 14. Top wall; 141. Second metal elastic member; 15. Bottom wall; 151. Sixth positioning point; 2. Digital micromirror device; 3. Lens; 4. Prism assembly; 41. First right-angle prism; 411. First right-angle side; 412. Second right-angle side; 42. Second right-angle prism; 421. First side; 422. Second side; 5. Metal block; 51. First contact portion; 511. Rod-shaped body; 52. Second contact portion; 521. Plate-shaped body; 522. Groove; 53. Abutting portion; 54. Notch; 6. First metal elastic member. Detailed implementation manners

[0042] The following describes the present invention based on embodiments, but the present invention is not limited to these embodiments. In the following detailed description of the present invention, some specific details are described in detail. To avoid obscuring the essence of the present invention, well-known methods, processes, procedures, and components are not described in detail.

[0043] In addition, those of ordinary skill in the art should understand that the drawings provided herein are for illustrative purposes only, and the drawings are not necessarily drawn to scale.

[0044] Unless the context clearly requires otherwise, the words such as "including" and "comprising" in the whole specification and claims should be interpreted as the meaning of including rather than exclusive or exhaustive; that is, the meaning of "including but not limited to".

[0045] In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0046] A projection optical machine, comprising a housing, a prism assembly, a digital micromirror device and a lens. The interior of the housing includes a receiving space for accommodating the prism assembly. The receiving space has a bottom wall, a first side wall and a second side wall. The digital micromirror device and the lens are fixed to the housing and their positions correspond to the first side wall and the second side wall respectively. The prism assembly includes a first right-angle prism and a second right-angle prism, and the plane where the hypotenuse of the first right-angle prism is located is fixed to the plane where the hypotenuse of the second right-angle prism is located.

[0047] The first right-angle prism has a first right-angle side parallel to the first side wall and with a side length of L, and a second right-angle side parallel to the second side wall and with a side length of A.

[0048] The first side wall and the second side wall are perpendicular, and an arc-shaped groove is provided at the junction of the two.

[0049] The three positioning points provided on the first side wall are a first positioning point, a second positioning point and a third positioning point respectively. The first positioning point is above the second positioning point, and their vertical projections on the bottom wall coincide, and the distance from the right-angle vertex of the first right-angle prism is 3 / 4L - 9 / 10L. The third positioning point and the second positioning point are at the same distance from the bottom wall, and the distance from the right-angle vertex of the first right-angle prism to the third positioning point is 1 / 4L - 3 / 5L.

[0050] The two positioning points provided on the second side wall are a fourth positioning point and a fifth positioning point. The projections of the fourth positioning point and the fifth positioning point on the bottom wall coincide, and the distance from the right-angle vertex of the first right-angle prism is 1 / 10A - 1 / 5A.

[0051] A metal block and a first metal elastic member at least partially located in the receiving space are accommodated in the receiving space. One end of the first metal elastic member is fixed to the housing, and the other end presses the metal block against the right angle of the second right-angle prism, and further presses the first right-angle prism against the positioning points on the first side wall and the second side wall. The extension line of the end of the first metal elastic member pressing against the metal block is located between the third positioning point and the fifth positioning point.

[0052] Each of the positioning points is integrally formed with the housing.

[0053] Refer to Figure 1 and Figure 2, the present invention provides a projection optical machine, comprising a housing 1, a digital micromirror device 2, a lens 3, a prism assembly 4, a metal block 5, and a first metal elastic member 6. The digital micromirror device 2 and the lens 3 are fixed to the side surface of the housing 1. The prism assembly 4 is disposed inside the housing 1. The metal block 5 is disposed inside the housing 1 and contacts the prism assembly 4. One end of the first metal elastic member 6 is fixed to the housing 1, and the other end penetrates through the housing 1 and abuts against the metal block 5 to press the prism assembly 4. The housing 1 can carry the digital micromirror device 2 and the lens 3 and protect the prism assembly 4 from being easily damaged. The metal block 5 and the first metal elastic member 6 can position the prism assembly 4 inside the housing 1 and satisfy the free movement of the prism assembly 4 under thermal expansion and contraction, and the movement consistency of the prism assembly 4 under thermal expansion and contraction is relatively good.

[0054] Referring to Figure 3 , the interior of the housing 1 includes a receiving space 11. The prism assembly 4 is received in the receiving space 11. The inner wall of the receiving space 11 includes a first side wall 12, a second side wall 13, a bottom wall 15, and a top wall 14 (the reference numerals are shown in Figure 4 ), wherein the first side wall 12 and the second side wall 13 are perpendicularly arranged. An incident light port 111, an exit light port 112, and a light passing port 113 are formed on the side wall of the receiving space 11. The light passing port 113 and the exit light port 112 are respectively disposed on the first side wall 12 and the second side wall 13. The digital micromirror device 2 is fixed to the first side wall 12 corresponding to the light passing port 113. The lens 3 corresponds to the position of the second side wall 13 corresponding to the exit light port 112. After the light emitted by the light source enters the position of the prism assembly 4 from the incident light port 111, it is transmitted to the digital micromirror device 2 through the light passing port 113 for processing, and then enters the lens 3 through the prism assembly 4 and the exit light port 112.

[0055] Please refer to again Figure 2 , the prism assembly 4 includes a first right-angle prism 41 and a second right-angle prism 42. The surfaces where the hypotenuses of the first right-angle prism 41 are located are fixed to the surfaces where the hypotenuses of the second right-angle prism 42 are located. The first right-angle prism 41 is disposed away from the metal block 5 relative to the second right-angle prism 42. The first metal elastic member 6 applies an elastic force to the metal block 5, and the metal block 5 abuts against the right-angle position of the second right-angle prism 42 to position the entire prism assembly 4 in this way.

[0056] As an embodiment, the housing 1 is further provided with a mounting hole 114 penetrating through the housing 1. The first metal elastic member 6 passes through the mounting hole 114 and is fixedly connected to the housing 1. One end of the first metal elastic member 6 extending into the receiving space 11 abuts against the metal block 5, and the metal block 5 presses the prism assembly 4 to position the prism assembly 4. Specifically, the metal block 5 applies a force to the prism assembly 4, such that the first right-angle prism 41 abuts against the first side wall 12 and the second side wall 13. It can be understood that the housing 1 does not necessarily need to be provided with the mounting hole 114 for the first metal elastic member 6 to pass through, and the structure of the first metal elastic member 6 penetrating into the housing 1 can be changed according to the different shapes of the first metal elastic member 6.

[0057] As an embodiment, the end of the first metal elastic member 6 away from the metal block 5 does not necessarily need to penetrate through the housing 1. It can directly abut against the inner wall of the housing 1 or in a counterbore provided in the inner wall of the housing 1, as long as the position of this end of the first metal elastic member 6 is fixed with respect to the housing 1.

[0058] A plurality of positioning points are provided in the receiving space 11, and the prism assembly 4 contacts the receiving space 11 through the positioning points. The contact area between the prism assembly 4 and the receiving space 11 is reduced, the frictional force received during the movement of the prism assembly 4 is reduced, the smoothness of the movement of the prism assembly 4 is improved, and the adverse effects of other components on imaging during thermal expansion and contraction are also greatly reduced (for example, if the housing 1 is made of plastic, during use, the movement consistency during thermal expansion and contraction at different times is very poor, and the movement consistency of the prism assembly 4 is greatly affected by it, while reducing the contact area can weaken this effect to a certain extent), which is beneficial to improving the movement consistency.

[0059] Referring to Figure 3 and Figure 4 , the three positioning points provided on the first side wall 12 are respectively a first positioning point 121, a second positioning point 122, and a third positioning point 123, and the three positioning points are arranged around the light passing port 113. The first positioning point 121 is located above the second positioning point 122 (the above here refers to the position relatively close to the top wall 14), and their vertical projections on the bottom wall 15 coincide. The third positioning point 123 and the second positioning point 122 are at the same distance from the bottom wall 15. The two positioning points provided on the second side wall 13 are a fourth positioning point 131 and a fifth positioning point 132, and the two positioning points are arranged around the light output port 112. The projections of the fourth positioning point 131 and the fifth positioning point 132 on the bottom wall 15 coincide. Through the above positioning points, in cooperation with the first metal elastic member 6 and the metal block 5, the prism assembly 4 can be accurately positioned, and the positioning points can reduce the frictional force when the prism assembly 4 moves, facilitate the free movement of the prism assembly 4 during thermal expansion and contraction, and the movement has consistency.

[0060] As an embodiment, the extension line of one end of the first metal elastic member 6 abutting against the metal block 5 is located between the third positioning point 123 and the fifth positioning point 132, defining the position of one end of the first metal elastic member 6 abutting against the metal block 5. This can enable the first metal elastic member 6 to transmit force to the prism assembly 4 more evenly. By making the first metal elastic member 6, the metal block 5, and each positioning point cooperate, the prism assembly 4 can be positioned more accurately. Moreover, it can also reduce the frictional force suffered by the prism assembly 4 during thermal expansion and contraction movement, and maintain the free movement of the prism assembly 4 due to thermal expansion and contraction.

[0061] As an embodiment, the first positioning point 121, the second positioning point 122, the third positioning point 123, the fourth positioning point 131, and the fifth positioning point 132 are integrally formed on the housing 1 to improve the position accuracy of the above positioning points. An arc-shaped groove 115 is provided at the junction of the first side wall 12 and the second side wall 13 (refer to Figure 3 ). Since higher dimensional accuracy is required for the positioning points, the commonly used integral forming process cannot meet the dimensional accuracy requirements of the positioning points. Therefore, the housing 1 needs to be machined with a precision machine tool. Due to the limited minimum size of the cutting tool, especially the distance between the fourth positioning point 131 and the fifth positioning point 132 from the junction of the mutually perpendicular first side wall 12 and the second side wall 12 is very small (specific distance parameters will be introduced later). Therefore, an arc-shaped groove 115 is left at the junction of the first side wall and the second side wall to facilitate machining. And the arc-shaped groove 115 makes the right angle of the first right-angle prism 41 not abut against the inner wall at this position, that is, the right angle of the first right-angle prism 41 is located within the arc-shaped groove 115, but it does not contact the inner wall of the arc-shaped groove 115 (refer to Figure 5 ).

[0062] As an embodiment, the opening of the arc-shaped groove 115 faces the fourth positioning point 131 and the fifth positioning point 132, which is beneficial to the machining of the fourth positioning point 131 and the fifth positioning point 132. It can be understood that the opening of the arc-shaped groove 115 does not necessarily face the fourth positioning point 131 and the fifth positioning point 132, and may change according to the specific structure of the housing 1.

[0063] The projection optical machine further includes a second metal elastic member 141. One end of the second metal elastic member 141 abuts against the prism assembly 4, and the other end is fixed to the top wall 14. And a sixth positioning point 151 is integrally provided on the bottom wall 15. The projection of the second metal elastic member 141 on the bottom wall 15 coincides with the sixth positioning point 151. By providing the second metal elastic member 141 and the sixth positioning point 151, the frictional force between the top wall 14 and the bottom wall 15 and the prism assembly 4 can be further reduced. And the projection of the second elastic member on the bottom wall 15 coincides with the sixth positioning point 151, which can evenly arrange the two on both sides of the prism assembly 4 to position the prism assembly 4. It can be understood that the second metal elastic member 141 and the sixth positioning point 151 are not necessarily provided. The consistency of the free movement of the prism assembly 4 can be improved by the multiple positioning points on the side wall one 12 and the side wall two 13.

[0064] As an embodiment, the distribution of the second metal elastic member 141 and the sixth positioning point 151 is not necessarily the above positions and can be changed according to the specific structure of the housing 1. For example, the second metal elastic member 141 can be provided on the bottom wall 15, and the sixth positioning point 151 can be provided on the top wall 14, and their projections on the bottom wall 15 coincide.

[0065] As an embodiment, the sixth positioning point 151 is also integrally formed on the housing 1. Integrally forming the sixth positioning point 151 on the housing 1 can improve the accuracy of the position of the sixth positioning point 151 on the housing 1, so as to accurately position the prism assembly 4. It can be understood that the forming method of the sixth positioning point 151 can also be changed according to the specific structure of the projection optical machine. As long as the sixth positioning point 151 can abut against the prism assembly 4 for positioning.

[0066] As an embodiment, the types of elastic members used for the first metal elastic member 6 and the second metal elastic member 141 are not limited. For example, both of them can be elastic plungers. It can be understood that the first metal elastic member 6 and the second metal elastic member 141 can provide the elastic force required for positioning the prism assembly 4 and both are hard materials.

[0067] As an embodiment, the area of the positioning point is 1-4 square centimeters. The area of the positioning point should not be too small, otherwise it is difficult to provide enough contact area for positioning the prism assembly 4; the area of the positioning point should not be too large, otherwise it is difficult to achieve the effect of reducing the frictional force of the movement of the prism assembly 4.

[0068] As an embodiment, the positioning points on the first side wall 12 and the second side wall 13 are square, and the positioning points on the bottom wall 15 are circular. The area of the square positioning points is more than 1.2 times the area of the circular positioning points. It can be understood that the shape of the positioning points is not limited. Triangular or elliptical positioning points can all achieve the positioning of the prism assembly 4. It's just that square positioning points are easier to process on the first side wall 12 and the second side wall 12. The relationship between the area of the square positioning points and the area of the circular positioning points is not necessarily the above relationship. It's just that the square positioning points on the first side wall 12 and the second side wall 13 have a larger area, which can better accurately position the prism assembly 4.

[0069] As an embodiment, the height of the positioning points is 0.3 - 1 cm. If the height of the positioning points is too high, it will press the prism assembly 4 and affect the free movement of the prism assembly 4. If the height of the positioning points is too low, it will be difficult to position the prism assembly 4 accurately. It can be understood that the height of the positioning points is not necessarily within the above range, and the height of the positioning points can be changed according to the distance between the inner wall of the housing 1 and the prism assembly 4.

[0070] Refer to Figure 3 and Figure 6 , the first right-angle prism 41 has a first right-angle side 411 parallel to the first side wall 12, and the side length of the first right-angle side 411 is L; and a second right-angle side 412 parallel to the second side wall 13, and the side length of the second right-angle side 412 is A. The positioning points on the first side wall 12 and the positioning points on the second side wall 13 can abut against the first right-angle prism 41, and the metal block 5 abuts against the second right-angle prism 42, thereby positioning the prism assembly 4.

[0071] As an embodiment, the distances from the first positioning point 121 and the second positioning point 122 to the right-angle vertex of the first right-angle prism 41 are 3 / 4L - 9 / 10L, and the distance from the third positioning point 123 to the right-angle vertex of the first right-angle prism 41 is 1 / 4L - 3 / 5L; the distances from the fourth positioning point 131 and the fifth positioning point 132 to the right-angle vertex of the first right-angle prism 41 are 1 / 10A - 1 / 5A. Light is propagated between the first right-angle prism 41, the digital micromirror device 2, and the lens 3. The positioning of the prism assembly 4 is based on the positioning of the first prism assembly 4. The positioning requirement between the first right-angle prism 41 and the digital micromirror device 2 is the highest, and the positioning accuracy requirement between the first right-angle prism 41 and the lens 3 is the second. When setting the prism assembly 4, it is necessary to accurately position the relative position between the first right-angle prism 41 and the digital micromirror device 2. Therefore, more positioning points are provided on the first side wall 12, and the number on the second side wall 13 is the second. And the multiple positioning points are arranged at the above distribution positions, thereby accurately positioning the first prism assembly 4. While meeting the positioning of the prism assembly 4, the prism assembly 4 can move freely when heated, and the consistency of the movement is relatively good.

[0072] As an embodiment, the sixth positioning point 151 abuts against the bottom surface of the first right-angle prism 41 and is located on the perpendicular bisector of its bottom surface. The perpendicular bisector passes through the right-angle vertex of the first right-angle prism 41, enabling the sixth positioning point 151 to be located at a position relatively centered with respect to the prism assembly 4 to position the prism assembly 4. By setting the sixth positioning point 151 on the perpendicular bisector of the bottom surface of the first right-angle prism 41 and cooperating with other positioning points, the positioning effect of the prism assembly 4 is improved.

[0073] As an embodiment, the second prism includes a first side surface 421 and a second side surface 422. The first side surface 421 and the second side surface 422 are two side surfaces at the right angle of the second right-angle prism 42. The first side surface 421 and the second side surface 422 can be used to contact the metal block 5 and transmit the elastic force applied by the first metal elastic member 6 to the metal block 5 to the prism assembly 4, thereby positioning the prism assembly 4.

[0074] Refer to Figure 7 , the metal block 5 includes a first contact portion 51, a second contact portion 52, and an abutting portion 53. One end of the first contact portion 51 is connected to the second contact portion 52, and the abutting portion 53 is fixedly connected to the end of the second contact portion 52 close to the first contact portion 51. The first contact portion 51 is closer to the light incident port 111 than the second contact portion 52. The first contact portion 51 contacts the first side surface 421, and the second contact portion 52 contacts the second side surface 422. Specifically, the second contact portion 52 can be adhesively fixed to the second side surface 422, thereby fixing the metal block 5 to the prism assembly 4. One end of the first metal elastic member 6 extending into the storage space 11 can apply an elastic force to the abutting portion 53, and the elastic force is applied to the first side surface 421 and the second side surface 422 through the first contact portion 51 and the second contact portion 52 respectively, thereby applying the elastic force to the prism assembly 4, positioning the prism assembly 4 in the accommodation space 11, and ensuring that the prism assembly 4 can move after being heated and cooled. Moreover, since the prism assembly 4 is made of a hard material with a smooth surface, and the materials of the metal block 5 and the first metal elastic member 6, the contacts between the prism assembly 4, the metal block 5, and the first metal elastic member 6 are all hard contacts, so that the elastic force required to move the prism assembly 4 is fixed, and its movement range due to thermal expansion and contraction is controllable, improving the imaging consistency during the use of the projection optical machine.

[0075] As an embodiment, the first contact portion 51 includes two rod-shaped bodies 511 spaced apart in the vertical direction, where the vertical direction is perpendicular to the top wall 14 and the bottom wall 15. The rod-shaped bodies 511 are in contact with the edge of the first side surface 421. Since the first side surface 421 corresponds to the light inlet 111, the light emitted by the light source is transmitted to the prism assembly 4 through the light inlet 111. By setting the first contact portion 51 as the rod-shaped bodies 511, while ensuring force conduction, the area of the first contact portion 51 blocking the first side surface 421 can be reduced, avoiding the first contact portion 51 affecting the light entering the prism assembly 4 from the first side surface 421. It can be understood that the shape of the first contact portion 51 is not limited and can be changed according to the change of the light incident position of the first side surface 421, as long as it can satisfy the contact with the first side surface 421 without affecting the light entering the prism assembly 4.

[0076] As an embodiment, the second contact portion 52 is a plate-shaped body 521. The plate-shaped body 521 covers at least the middle position of the second side surface 422. A groove 522 is formed on one side of the plate-shaped body 521 facing the second side surface 422. The inner wall of the groove 522 is not in contact with the second side surface 422. The second side surface 422 is not used for light propagation. By using the plate-shaped body 521 as the second contact portion 52, it is convenient to more evenly transmit the force applied by the first metal elastic member 6 to the prism assembly 4, improving the positioning effect on the prism assembly 4. And forming the groove 522 on the surface of the plate-shaped body 521 can perform glue dispensing in the groove 522 to bond the second side surface 422 and the second contact portion 52 together, bonding the prism assembly and the metal block 5 together, so that the force applied by the first metal elastic member 6 is evenly applied to the prism assembly 4, facilitating the movement of the prism assembly 4 due to thermal expansion and contraction. It can be understood that the shape of the second contact portion 52 can also be other shapes, such as rod-shaped, etc., as long as the second contact portion 52 can contact the second side surface 422 and transmit the elastic force applied by the first metal elastic member 6 to the prism assembly 4. As an embodiment, the second contact portion 52 is only in contact with the second side surface 422 and is not fixedly connected by glue or the like.

[0077] As an embodiment, a groove 522 is not necessarily formed on one side of the plate-shaped body 521 facing the second side surface 422. The glue can be directly coated on the surface of the plate-shaped body 521 or the surface of the second side surface 422.

[0078] As an embodiment, an included angle is provided between the abutting portion 53 and the second contact portion 52, and the angle of the included angle can be adjusted, as long as it is ensured that the second contact portion 52 is in contact with or fixed to the second side surface 422, and the surface of the end of the first metal member 6 extending into the receiving space 11 in contact with the abutting portion 53 is perpendicular or nearly perpendicular.

[0079] As an embodiment, a notch 54 is provided between the abutting portion 53 and the second contact portion 52. It can be understood that the notch 54 may not be provided between the two. It only means that during the installation process, when the metal block 5 is relatively fixed to the second right-angled prism 42, it is convenient for the staff to clamp and operate.

[0080] In a second aspect, the present application further provides a projector, including a housing, and the above-mentioned projection optical machine is accommodated in the housing. By using the above-mentioned projection optical machine, the first metal elastic member, the metal block, and multiple positioning points cooperate to be able to position the prism assembly. And when the prism assembly moves due to heat, the first metal elastic member and the metal block can allow the prism assembly to move freely. By using the above-mentioned multiple positioning points and the distribution positions of the positioning points, the contact area between the prism assembly and the receiving space can be reduced, the friction force required for the movement of the prism assembly can be reduced, and the smoothness of the movement of the prism assembly can be improved. Since the first elastic metal member and the metal block, the metal block and the prism assembly, and the prism assembly and each positioning point are all in hard contact, the consistency of the thermal expansion and contraction movement of the prism assembly is relatively good.

[0081] Those skilled in the art can understand that, on the premise of no conflict, the above-mentioned preferred solutions can be freely combined and superimposed.

[0082] It should be understood that the above-mentioned embodiments are merely exemplary and not restrictive. Without departing from the basic principles of the present invention, various obvious or equivalent modifications or substitutions made by those skilled in the art to the above details will all be included within the scope of the claims of the present invention.

Claims

1. A projection optical machine, comprising a housing, a prism assembly, a digital micromirror device and a lens. The interior of the housing includes a receiving space for accommodating the prism assembly. The receiving space has a bottom wall, a first side wall and a second side wall. The digital micromirror device and the lens are fixed to the housing and their positions correspond to the first side wall and the second side wall respectively. The prism assembly includes a first right-angle prism and a second right-angle prism. The surface where the hypotenuse of the first right-angle prism is located is fixed to the surface where the hypotenuse of the second right-angle prism is located. It is characterized in that: The first right-angle prism has a first right-angle side parallel to the first side wall with a side length of L, and a second right-angle side parallel to the second side wall with a side length of A; The first side wall and the second side wall are perpendicular, and an arc-shaped groove is provided at the junction of the two; The three positioning points provided on the first side wall are respectively a first positioning point, a second positioning point and a third positioning point. The first positioning point is above the second positioning point, and their vertical projections on the bottom wall coincide, and the distance from the right-angle vertex of the first right-angle prism is 3 / 4L - 9 / 10L; The third positioning point has the same distance from the bottom wall as the second positioning point, and the distance from the right-angle vertex of the first right-angle prism is 1 / 4L - 3 / 5L; The two positioning points provided on the second side wall are a fourth positioning point and a fifth positioning point. The fourth positioning point and the fifth positioning point coincide in their projections on the bottom wall, and the distance from the right-angle vertex of the first right-angle prism is 1 / 10A - 1 / 5A; A metal block and a first metal elastic member at least partially located in the receiving space are accommodated in the receiving space. One end of the first metal elastic member is fixed to the housing, and the other end presses the metal block against the right angle of the second right-angle prism, and then presses the first right-angle prism against the positioning points on the first side wall and the second side wall; The extension line of the end of the first metal elastic member pressing on the metal block is located between the third positioning point and the fifth positioning point; Each of the positioning points is integrally formed with the housing.

2. The projection optical machine according to claim 1, wherein: The area of the positioning point is 1 - 4 square centimeters; the height of the positioning point is 0.3 - 1 cm.

3. The projection optical machine according to claim 1, wherein: The projection optical machine further includes a second metal elastic member. The receiving space has a top wall. One end of the second metal elastic member presses against the prism assembly, and the other end is fixed to the top wall; A sixth positioning point is provided on the bottom wall. The projection of the second metal elastic member on the bottom wall coincides with the position of the sixth positioning point.

4. The projection optical machine according to claim 3, characterized in that: The positioning points on the first side wall and the second side wall are square, and the positioning point on the bottom wall is circular, and the area of the square positioning point is more than 1.2 times the area of the circular positioning point.

5. The projection optical machine according to claim 3, characterized in that: The sixth positioning point is integrally formed with the housing.

6. The projection optical machine according to claim 3, characterized in that: The sixth positioning point presses against the bottom surface of the first right-angle prism and is located on the vertical bisector of its bottom surface. The vertical bisector passes through the right-angle vertex of the first right-angle prism.

7. The projection optical machine according to claim 1, characterized in that: The opening of the arc-shaped groove faces the fourth positioning point and the fifth positioning point.

8. The projection optical machine according to claim 1, wherein: The right angle of the first right-angled prism is located within the arc-shaped groove and does not contact the inner wall of the arc-shaped groove.

9. The projection optical machine according to claim 1, wherein: The housing is provided with a mounting hole penetrating the housing. The first metal elastic member passes through the mounting hole and is fixedly connected to the housing, and the end extending into the accommodation space abuts against the metal block.

10. The projection optical machine according to claim 1, wherein: The housing is provided with a light inlet. The metal block includes a first contact portion and a second contact portion, and the first contact portion is closer to the light inlet than the second contact portion. The first contact portion and the second contact portion are respectively in contact with the first side surface and the second side surface at the right angle of the second right-angled prism. The first contact portion includes two rod-shaped bodies spaced apart in the vertical direction, and the rod-shaped bodies are in contact with the edge portion of the first side surface. The second contact portion is a plate-shaped body, and the plate-shaped body at least covers the middle position of the second side surface.

11. The projection optical machine according to claim 10, characterized in that: A groove is formed on the surface of the plate-shaped body facing the second side surface, and the plate-shaped body is adhesively fixed to the second side surface.

12. The projection optical machine according to claim 10, wherein: The metal block further includes an abutting portion fixedly connected to the end of the second contact portion close to the first contact portion. The abutting portion and the second contact portion are arranged at an angle, and there is a notch between the two.

13. A projector, comprising a housing, characterized in that: The housing houses the projection optical machine according to any one of claims 1-12.

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