Focusing module and projection device

Abstract

The focusing module includes a focusing ring and a lens mounting ring. The focusing ring has a first ring body and a first annular wall connecting to and surrounding the first ring body. The first annular wall has opposing inner and outer annular surfaces and a limiting hole penetrating the inner and outer annular surfaces. The lens mounting ring has a second annular wall for fixing the lens. The second annular wall is located inside the first annular wall and can rotate relative to the first annular wall in the circumferential direction. The second annular wall has a perforation and a rotation buffer structure located within the perforation. The rotation buffer structure has a limiting portion and a cantilever portion connecting the limiting portion and the edge of the perforation. The limiting portion has a center surrounded by the edge of the hole and protruding toward the first annular wall, and the center has opposing first and second sides in the circumferential direction. In the radial direction of the second annular wall, the thickness of the limiting portion gradually decreases from the center toward the first and second sides. When the limiting portion abuts against the limiting hole, the center is located within the limiting hole and the first annular wall presses against the first and second sides. The present invention also provides a projection device including the focusing module.

Description

Technical Field

[0001] The present invention relates to a focusing module, particularly a focusing module for a projection device, and a projection device including the focusing module. Background Technology

[0002] Lens assemblies used in projectors typically consist of a focus ring and a lens. Generally, the focus ring is fixed to the lens, allowing the user to easily rotate it to move it in conjunction with the lens to focus. Furthermore, the focus ring usually has a locking mechanism for securing it to the lens; when the lens rotation reaches a critical value, the focus ring locks into place, preventing both the focus ring and the lens from rotating further in the same direction.

[0003] However, many users often fail to notice that the lens rotation has reached the critical value and continue to forcefully rotate the focusing ring, causing damage to the aforementioned locking structure.

[0004] This "Background Art" section is only for the purpose of helping to understand the content of this invention. Therefore, the content disclosed in the "Background Art" section may include some known technologies that are not known to those skilled in the art. In addition, the content disclosed in the "Background Art" section does not represent the problems to be solved by such content or one or more embodiments of this invention, nor does it represent that it was known or recognized by those skilled in the art prior to this application. Summary of the Invention

[0005] This invention provides a focusing module for a lens to prevent damage to the structure of the focusing module and the lens due to excessive rotation of the focusing ring.

[0006] The present invention provides a projection device with the advantage of high durability.

[0007] Other objects and advantages of the present invention can be further understood from the technical features disclosed herein.

[0008] To achieve one, some, or all of the above objectives, or other objectives, the focusing module provided by the present invention is used for a lens having an optical axis. The focusing module includes a focusing ring and a lens mounting ring. The focusing ring has a first ring body and a first annular wall. The first ring body has opposing first and second openings, and the first annular wall is connected to the first ring body and surrounds the first opening. The first annular wall has a limiting hole, an inner annular surface, and an outer annular surface. The inner and outer annular surfaces are opposite each other, and the limiting hole penetrates the inner and outer annular surfaces of the first annular wall in a direction perpendicular to the optical axis. The lens mounting ring has a second annular wall for fixing to the lens along the optical axis. The second annular wall is disposed inside the first annular wall and is used for rotating relative to the first annular wall circumferentially. The second annular wall has a perforation and a rotation buffer structure. The rotation buffer structure is located within the perforation and has a limiting portion and a cantilever portion. The cantilever portion connects the limiting portion and the edge of the perforation, and the limiting portion has a center surrounded by the edge of the perforation. The center protrudes towards the first annular wall facing the focusing ring and has opposing first and second sides in the circumferential direction. In the radial direction of the second annular wall, the thickness of the limiting portion gradually decreases from the center towards the first side and towards the second side. When the limiting portion of the rotating buffer structure abuts against the limiting hole of the focusing ring, the center of the limiting portion is located within the limiting hole, and the first annular wall presses against the first and second sides.

[0009] To achieve one or more of the above-mentioned objectives, or other objectives, the projection device provided by the present invention includes a housing, an illumination system, a light valve, and a lens assembly. The illumination system is disposed within the housing and provides an illumination beam. The light valve is disposed within the housing and located in the transmission path of the illumination beam from the illumination system to convert the illumination beam into an image beam. The housing has an opening. The lens assembly includes a lens and the aforementioned focusing module. The lens of the lens assembly is disposed in the opening and located in the transmission path of the image beam from the light valve to project the image beam out of the projection device. The lens has an optical axis, and the focusing module is connected to the lens.

[0010] In the focusing module of the present invention, the focusing ring has a limiting hole, and the lens mounting ring has a rotation buffer structure corresponding to the limiting hole, and the limiting part of the rotation buffer structure can be located within the limiting hole. Furthermore, the thickness of the limiting part gradually decreases from the center towards the opposing first and second sides, and the first annular wall can press against the first and second sides. Therefore, when the focusing ring is subjected to excessive rotational force, the first annular wall will gradually move from the second side (or the first side) towards the center, thereby pressing against the center and causing the center to disengage from the limiting hole. In this case, because the center is pressed against by the first annular wall, if the focusing ring is continuously rotated, the second annular wall will move along the first annular wall. Thus, the focusing ring can rotate relative to the lens mounting ring, rather than causing the lens mounting ring to rotate together, thereby preventing damage to the structure of the focusing module and the lens due to excessive rotation of the focusing ring. On the other hand, because the projection device of the present invention uses the above-described focusing module, it has the advantage of excellent durability.

[0011] To make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the assembly of the focusing module and lens according to an embodiment of the present invention.

[0013] Figure 2 yes Figure 1 An exploded view of the focusing module and locking mechanism.

[0014] Figure 3 yes Figure 1 A cross-sectional view of the focusing module.

[0015] Figure 4 yes Figure 2 An enlarged schematic diagram of the rotating buffer structure.

[0016] Figure 5 yes Figure 1 A magnified diagram of region Z.

[0017] Figure 6 yes Figure 5 A cross-sectional view showing the center of the object located within the limiting hole.

[0018] Figure 7 yes Figure 5 A schematic diagram of the first annular wall pressing against the center.

[0019] Figure 8 yes Figure 7 A cross-sectional view of the first annular wall pressing against the center.

[0020] Figure 9 This is a schematic diagram of the fastener being fixed inside the mounting opening.

[0021] Figure 10 This is a schematic diagram of a projection device according to an embodiment of the present invention. Detailed Implementation

[0022] The foregoing descriptions and other technical contents, features, and effects of this invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The directional terms used in the following embodiments, such as up, down, left, right, front, or back, are merely for reference to the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the invention.

[0023] Figure 1 This is a schematic diagram of the assembly of the focusing module and lens according to an embodiment of the present invention. Please refer to it. Figure 1The focusing module 100 is used for the lens L and includes a focusing ring 110 and a lens mounting ring 120. The lens mounting ring 120 is used to fix the lens L, and the focusing ring 110 is connected to the lens mounting ring 120. If the lens L is, for example, a projection lens and has an optical axis A, then the focusing module 100 can be used to adjust the focal length of the projection lens. The features of the focusing ring 110 and the lens mounting ring 120 will be described below.

[0024] Figure 2 yes Figure 1 An exploded view of the focusing module and locking mechanism. Figure 3 yes Figure 1 A cross-sectional view of the focusing module. Please refer to this as well. Figure 1 , Figure 2 and Figure 3 The focusing ring 110 has a first ring body 111 and a first annular wall 112, both of which are, for example, annular members. The first ring body 111 has a first opening O1 and a second opening O2, which are connected. The first annular wall 112 is connected inside the first ring body 111 and surrounds the first opening O1. The first annular wall 112 has a limiting hole H1 (drawn in...). Figure 2 The inner annular surface IS1 and the outer annular surface OS1 are respectively. The inner annular surface IS1 and the outer annular surface OS1 are opposite to each other, and the limiting hole H1 passes through the inner annular surface IS1 and the outer annular surface OS1 of the first annular wall 112 along a direction perpendicular to the optical axis A of the lens L. Incidentally, in this embodiment, the limiting hole H1 extends to the top edge of the first annular wall 112, for example, but other embodiments are not limited to this.

[0025] Please continue to refer to Figure 1 and Figure 2 In this embodiment, the lens mounting ring 120 has a second annular wall 121, which is used to fix the lens L along the optical axis A. The second annular wall 121 is disposed inside the first annular wall 112, and is used to rotate relative to the first annular wall 112 along the circumferential direction D1. The second annular wall 121 has a through hole H2 and a rotation buffer structure 1211. The through hole H2, for example, passes through the second annular wall 121 along a direction perpendicular to the optical axis A of the lens L. When the lens mounting ring 120 and the focusing ring 110 are fitted onto the lens L along the optical axis A, the second annular wall 121 of the lens mounting ring 120 is disposed inside the first annular wall 112 of the focusing ring 110, that is, both the second annular wall 121 of the lens mounting ring 120 and the first annular wall 112 of the focusing ring 110 are arranged around the optical axis A.

[0026] Figure 4 yes Figure 2 An enlarged schematic diagram of the rotating buffer structure. Figure 5 yes Figure 1A magnified diagram of region Z. Please refer to... Figure 1 , Figure 2 , Figure 4 and Figure 5 The rotating buffer structure 1211 of the lens mounting ring 120 is located within the perforation H2 and has a limiting portion 1211a and a cantilever portion 1211b. The cantilever portion 1211b connects the limiting portion 1211a and the edge 1210 of the perforation H2. The limiting portion 1211a has a center C surrounded by the edge 1210. Specifically, one end of the cantilever portion 1211b is connected to the edge of the perforation H2, for example, while its other end is connected to the limiting portion 1211a along the direction parallel to the optical axis A. That is, the cantilever portion 1211b and the limiting portion 1211a are connected, for example, along the direction parallel to the optical axis A (drawn on...). Figure 1 The orientation configuration is as shown, but the present invention is not limited thereto. In this embodiment, when the lens mounting ring 120 and the focusing ring 110 are sleeved on the lens L along the optical axis A, the center C of the limiting part 1211a faces the first annular wall 112 (drawn on...). Figure 5 It protrudes in the direction of ) and in the circumferential direction D1 (marked at) Figure 1 and Figure 2 It has a first side S1 and a second side S2 that are opposite each other. Also, please refer to... Figure 6 On the radial direction D2 of the second annular wall 121, the center C is between the first side S1 and the second side S2, and the thickness T of the limiting part 1211a can gradually decrease from the center C toward the first side S1 and toward the second side S2.

[0027] Please continue the exam. Figure 5 and Figure 6 When the limiting portion 1211a of the rotating buffer structure 1211 abuts against the limiting hole H1 of the first annular wall 112 of the focusing ring 110, the center C of the limiting portion 1211a, which protrudes toward the first annular wall 112, presses against the first side S1 and the second side S2 of the limiting portion 1211a located inside the limiting hole H1 and the first annular wall 112 (i.e., the edge of the limiting hole H1) (marked as follows) Figure 4 Therefore, when the focusing ring 110 moves along the circumferential direction D1 (marked at...), Figure 5 When the lens mounting ring 120 rotates relative to the focusing ring 110 and the rotational force on the focusing ring 110 exceeds the threshold, such as Figure 5 and Figure 7 As shown, the position of the first annular wall 112 of the focusing ring 110 pressing against the lens mounting ring 120 can be moved from the second side S2 of the limiting part 1211a to the center C of the limiting part 1211a, so that the center C of the limiting part 1211a disengages from the limiting hole H1 of the first annular wall 112. Thus, the first annular wall 112 can continuously move along the circumferential direction D1 (marked...). Figure 5 The second annular wall 121 of the lens mounting ring 120 rotates relative to the lens mounting ring 120 to prevent the focusing module 100 from interfering with the lens L (drawn on...). Figure 1Damaged due to excessive rotation of the focusing ring 110. Further details can be found in the following references. Figure 4 , Figure 5 and Figure 6 The first side S1 and the second side S2 of the center C of the limiting part 1211a may each have a guiding slope GS, so that the position of the first annular wall 112 pressing against the lens mounting ring 120 can move along the guiding slope GS from the second side S2 (or the first side S1) to the center C, making it easier for the focusing ring 110 to rotate relative to the lens mounting ring 120. Please continue to refer to Figure 4 In this embodiment, the guide ramp GS can be set to surround the center C, but the present invention is not limited thereto; for example, in one embodiment, the guide ramp GS can be set only on the first side S1 and the second side S2.

[0028] Figure 8 yes Figure 7 A cross-sectional view showing the first annular wall pressing against the center. Please refer to this as well. Figure 7 and Figure 8 In this embodiment, the cantilever portion 1211b of the rotating buffer structure 1211 of the lens mounting ring 120 undergoes elastic deformation when its center C disengages from the limiting hole H1 of the first annular wall 112 and is pressed against by the first annular wall 112. Furthermore, the cantilever portion 1211b will move away from the inner annular surface IS1 (drawn on...). Figure 8 The cantilever portion 1211b undergoes elastic deformation in the direction of the optical axis A, i.e., elastic deformation in the direction away from the inner ring surface IS1. When the center C of the limiting portion 1211a leaves the limiting hole H1, the center C presses against the inner ring surface IS1 of the first annular wall 112 of the focusing ring 110, causing the focusing ring 110 to rotate relative to the lens mounting ring 120. Incidentally, in this embodiment, the cantilever portion 1211b is integrally formed with the limiting portion 1211a, but in another embodiment, the cantilever portion 1211b may include a spring structure with elastic deformation function.

[0029] On the other hand, please refer to... Figure 1 and Figure 5 In this embodiment, when the rotational force experienced by the focusing ring 110 is less than or equal to the threshold value, the first annular wall 112 of the focusing ring 110 presses against the first side S1 and the second side S2 of the limiting portion 1211a (drawn on...). Figure 4 At least a portion of the center C is engaged within the limiting hole H1 of the first annular wall 112, allowing the focusing ring 110 to drive the lens mounting ring 120 to rotate synchronously. Specifically, the first annular wall 112 of the focusing ring 110 can surround the outer side of the second annular wall 121 with the optical axis A as the center, and the inner annular surface IS1 of the first annular wall 112 (drawn on...) Figure 2 and Figure 3The focusing ring 110 can rotate towards the second annular wall 121. When the focusing ring 110 rotates around the optical axis A, the edge of the limiting hole H1 of the focusing ring 110 can press against the limiting part 1211a of the rotation buffer structure 1211, thereby pushing against the lens mounting ring 120, so that the lens mounting ring 120 rotates synchronously with the focusing ring 110. Furthermore, the edge of the limiting hole H1 and the local inner annular surface IS1 near the edge of the hole can press against the first side S1 and the second side S2, so that the focusing ring 110 can drive the lens mounting ring 120 to rotate synchronously when the rotational force is less than or equal to the threshold.

[0030] Please refer to this again. Figure 2 To facilitate user judgment of the rotational state of the focusing ring 110 and the lens mounting ring 120, the inner annular surface IS1 of the first annular wall 112 of the focusing ring 110 may have multiple segmented structures 1120. Each segmented structure 1120 is spaced apart from each other, and each segmented structure 1120 is arranged circumferentially D1 and corresponds to the center C of the rotation buffer structure 1211. Thus, when the focusing ring 110 rotates relative to the lens mounting ring 120, the center C of the limiting portion 1211a will sequentially press against these segmented structures 1120 as it moves along the inner annular surface IS1, providing a tactile feel of segmented rotation and producing a sound as the center C passes through these segmented structures 1120, allowing the user to know the current rotational state. It is understood that the detailed features of the segmented structures 1120 may vary depending on the structure of the center C; for example, in this embodiment, the center C may include a plane, and the shape of each segmented structure 1120 may protrude from the inner annular surface IS1, i.e., protrude towards the optical axis A. In other embodiments, the shape of the segment structure 1120 may also include a recess in the inner annular surface IS1, and the present invention does not impose further limitations on this.

[0031] Incidentally, the number of limiting holes H1 in this embodiment may include multiple holes, with three shown as examples in the figure. The number of through holes H2 corresponds to the number of limiting holes H1, and each limiting hole H1 and through hole H2 is equidistant from each other on the circumferential direction D1. In this way, the focusing ring 110 can be easily rotated to a position where the limiting holes H1 and the limiting part 1211a are aligned with each other, thereby improving the convenience of operation. The specific number of limiting holes H1 may depend on the overall structural strength of the focusing ring 110, so the present invention does not impose any restrictions on this.

[0032] Please refer to this as well. Figure 2 and Figure 3 This illustrates the assembly method and corresponding features of the focusing ring 110 and the lens mounting ring 120. The lens mounting ring 120 also has a third opening O3 and a fourth opening O4. The third opening O3 and the fourth opening O4 are located on opposite sides of the second annular wall 121, are connected, and the second annular wall 121 surrounds the third opening O3 and the fourth opening O4. The lens L is positioned through the fourth opening O4 of the lens mounting ring 120. Figure 3 As shown, the second annular wall 121 has a third side 122 near the third opening O3 and a fourth side 123 near the fourth opening O4. The outer diameter OR1 of the second annular wall 121 of the lens mounting ring 120 on the fourth side 123 is smaller than the inner diameter IR of the first opening O1 of the first ring body 111 of the focusing ring 110, and the outer diameter OR2 of the second annular wall 121 of the lens mounting ring 120 on the third side 122 is larger than the inner diameter IR of the first opening O1 of the first ring body 111 of the focusing ring 110. Therefore, when assembling the focusing ring 110 and the lens mounting ring 120, the fourth side 123 of the lens mounting ring 120 can be inserted into the focusing ring 110 from the second opening O2 toward the first opening O1 and fixed to the first opening O1; the third side 122 of the lens mounting ring 120 can be fixed inside the second opening O2 of the focusing ring 110. In this embodiment, the third side 122 has, for example, an annular base B. The annular base B extends outward along the outer edge of the third side 122 in a direction perpendicular to the optical axis A to increase the outer diameter OR2, so that the annular base B of the third side 122 can be stopped inside the focusing ring 110. However, the specific structure of the third side 122 is not limited to this.

[0033] Please refer to this as well. Figure 1 , Figure 2 , Figure 3 and Figure 9 This illustrates the method by which the lens mounting ring 120 is assembled onto the lens L and its corresponding features. The second annular wall 121 of the lens mounting ring 120 is used to secure it to the lens L via a plurality of fasteners SE in a direction perpendicular to the optical axis A. Each fastener SE has a connected shaft portion SE1 and a head SE2. The second annular wall 121 also has an inner surface IS2 (also shown in...). Figure 3 ), outer side OS2 (also drawn on Figure 3 The annular top edge 1212 and a plurality of mounting ports 1213 are connected between the inner side surface IS2 and the outer side surface OS2 and are located on the fourth side O4 of the second annular wall 121. The mounting ports 1213 are, for example, circumferentially spaced, and each mounting port 1213 extends through the inner side surface IS2 and the outer side surface OS2 of the second annular wall 121 in a direction perpendicular to the optical axis A and extends to the annular top edge in a direction parallel to the optical axis A. Figure 9 As shown, each mounting port 1213 has two opposing hook portions 1213a. A clamping area CA and a channel area TA are formed between the two hook portions 1213a. The channel area TA communicates with the clamping area CA along a direction parallel to the optical axis A and extends to the annular top edge 1212. Please refer to the above description. Figure 1 and Figure 9These fasteners SE are locked to the outer side of the lens barrel (unlabeled) of the lens L along a direction perpendicular to the optical axis A, with the shaft portion SE1 of the fastener SE being locked to the lens L, and the other part of the shaft portion SE1 and the head SE2 exposed outside the lens L. When the lens mounting ring 120 is assembled to the lens L along the optical axis A, the two hook portions 1213a in each mounting opening 1213 of the second annular wall 121 are deformed to fix the exposed shaft portion SE1 of the lens L within the clamping area CA through the channel area TA. Specifically, the shaft portion SE1, for example, has a transition fit with the channel area TA and the clamping area CA, while the head SE2 can have an interference fit with the clamping area CA. Please refer to [further details omitted]. Figure 1 , Figure 2 and Figure 9 When assembling the lens mounting ring 120 and the lens L, first lock the fastener SE onto the lens L and align the channel area TA on the second annular wall 121 with the shaft SE1, then insert the lens L through the third opening O3 (drawn on...). Figure 2 Insert the lens mounting ring 120 into the lens mounting ring 120. In this way, the shaft portion SE1 of the locking fastener SE can extend from the channel area TA between the two hook portions 1213a along the optical axis A and be fixed in the clamping area CA, so that the two hook portions 1213a are deformed by the pressure of the shaft portion SE1. When the shaft portion SE1 moves into the clamping area CA, the two hook portions 1213a will reset. The reset hook portions 1213a and the head SE2 can prevent the locking fastener SE from falling off from the clamping area CA, so that the lens mounting ring 120 of this embodiment can be quickly assembled on the lens L and can be axially limited by the hook portions 1213a. When the focusing ring 110 rotates around the optical axis A, the edge of the limiting hole H1 of the focusing ring 110 can press against the limiting part 1211a of the rotating buffer structure 1211, thereby pushing against the lens mounting ring 120, so that the lens mounting ring 120 and the focusing ring 110 rotate synchronously, and the lens L locked to the lens mounting ring 120 will also be driven to adjust the focal length synchronously.

[0034] Incidentally, the locking fastener SE in this embodiment may include a stepped screw, so the shaft SE1 may have a connected wide section and a narrow section (neither shown), wherein the narrow section has external threads for screwing onto the lens L, and the wide section may connect between the narrow section and the head SE2. The clamping area CA, for example, clamps the wide section. When removing the lens mounting ring 120 from the lens L, the locking fastener SE on the lens L can be loosened from the head SE2 and the narrow section can be moved into the clamping area CA, so that the shaft SE1 can pass more easily through the channel area TA, making the lens mounting ring 120 easier to remove.

[0035] Compared to known technologies, in the focusing module 100 of this embodiment, the focusing ring 110 has a limiting hole H1, and the lens mounting ring 120 has a rotating buffer structure 1211 corresponding to the limiting hole H1, and the limiting portion 1211a of the rotating buffer structure 1211 can be located within the limiting hole H1. Furthermore, the thickness T of the limiting portion 1211a gradually decreases from the center C towards the opposing first side S1 and second side S2, and the first annular wall 112 can press against the first side S1 and second side S2 of the limiting portion 1211a. Therefore, when the focusing ring 110 experiences excessive rotational force, the first annular wall 112 will gradually move from the second side S2 (or the first side S1) towards the center C, thereby pressing against the center C and causing the center C to disengage from the limiting hole H1. In this case, because the center C is pressed against by the first annular wall 112, if the focusing ring 110 is continuously rotated, the second annular wall 121 will move relative to the first annular wall 112. In this way, the focusing ring 110 can rotate relative to the lens mounting ring 120, rather than causing the lens mounting ring 120 to rotate together, thereby preventing the focusing module 100 and the lens L from being damaged due to excessive rotation of the focusing ring 110.

[0036] Figure 10 This is a schematic diagram of a projection device according to an embodiment of the present invention. Please refer to it. Figure 10 The projection device 200 includes a housing 210, an illumination system 220, a light valve 230, and a lens assembly 240. The illumination system 220 is disposed within the housing 210 and provides an illumination beam L1. The light valve 230 is disposed within the housing 210 and located in the transmission path of the illumination beam L1 to convert the illumination beam L1 into an image beam L2. The housing 210 has an opening 211. The lens assembly 240 is disposed in the opening 211 and located in the transmission path of the image beam L2 to project the image beam L2 out of the projection device 200. The lens assembly 240 includes the aforementioned lens L and a focusing module 100, which is connected to the lens L. For example, in this embodiment, a focusing ring 110 is disposed beside the opening 211, and a lens mounting ring 120 can be connected between the focusing ring 110 and the lens L. The user can rotate the focusing ring 110 and, in conjunction with the lens L, perform a focusing operation. Since the features of the focusing module 100 have been described in detail above, the relevant description is omitted here.

[0037] The lighting system 220 can generate an illumination beam L1. In this embodiment, the lighting system 220 may include an excitation light source and a wavelength conversion element. The excitation light source may include, for example, a light-emitting diode (LED) or a laser diode (LD), wherein the number of LEDs or laser diodes may be one or more. For example, when the number of LEDs (or laser diodes) is multiple, the LEDs (or laser diodes) may be arranged in a matrix. The excitation light source can generate an excitation beam, and the wavelength conversion element is disposed on a wavelength conversion material, which can convert the excitation beam into the illumination beam L1. Specifically, the wavelength of the excitation beam incident on the wavelength conversion material is converted by the wavelength conversion material, while the wavelength of the excitation beam not incident on the wavelength conversion material is not converted. The unconverted excitation beam and the converted beam together form the illumination beam L1. In another embodiment, the lighting system 220 may include a metal halide lamp or an ultra-high pressure mercury lamp, but the present invention does not impose further limitations on this.

[0038] The light valve 230 in this embodiment includes, for example, a digital micromirror device (DMD), but the invention is not limited thereto. For example, in one embodiment, the light valve 230 may include a liquid crystal on silicon (LCoS) or a liquid crystal display (LCD) panel. Furthermore, this embodiment does not limit the number of light valves. For example, in an embodiment where the light valve 230 includes the aforementioned liquid crystal display panel, the projection device 200 may employ a monolithic liquid crystal display panel or a three-panel liquid crystal display panel architecture, but the invention is not limited thereto.

[0039] In this embodiment, the lens L includes one or more optical lenses housed within a lens barrel (not labeled), and the refractive powers of the optical lenses may be the same or different. For example, the optical lenses may include various non-planar lenses such as biconcave lenses, biconvex lenses, concave-convex lenses, convex-concave lenses, plano-convex lenses, and plano-concave lenses, or any combination thereof. Alternatively, the lens L may also include planar optical lenses. This invention does not impose many limitations on the specific structure of the lens L.

[0040] Compared to known technologies, the projection device 200 of this embodiment uses the aforementioned focusing module 100, which has the advantage of high durability.

[0041] In summary, in the focusing module of the present invention, the focusing ring has a limiting hole, and the lens mounting ring has a corresponding rotational buffer structure for the limiting hole, and the limiting part of the rotational buffer structure can be located within the limiting hole. Furthermore, the thickness of the limiting part gradually decreases from the center towards the opposing first and second sides, and the first annular wall can press against the first and second sides. Therefore, when the focusing ring experiences excessive rotational force, the first annular wall will gradually move from the second side (or the first side) towards the center, thereby pressing against the center and disengaging the center from the limiting hole. In this case, because the center of the limiting part is pressed against by the first annular wall, if the focusing ring is continuously rotated, the second annular wall will move along the first annular wall. Thus, the focusing ring can rotate relative to the lens mounting ring, rather than causing the lens mounting ring to rotate together, thereby preventing damage to the structure of the focusing module and the lens due to excessive rotation of the focusing ring. On the other hand, because the projection device of the present invention uses the above-described focusing module, it has the advantage of excellent durability.

[0042] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Any simple equivalent changes and modifications made in accordance with the claims and description of the invention are still within the scope of this patent. Furthermore, no embodiment or claim of the present invention needs to achieve all the objectives, advantages, or features disclosed in the invention. In addition, the abstract and title (invention title) are only used to assist in patent document retrieval and are not intended to limit the scope of the invention. Furthermore, the terms "first," "second," etc., mentioned in this specification or claims are only used to name elements or distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements.

[0043] Explanation of reference numerals in the attached figures:

[0044] 100: Focusing module

[0045] 110: Focusing ring

[0046] 111: First Ring Body

[0047] 112: First annular wall

[0048] 120: Lens mounting ring

[0049] 121: Second annular wall

[0050] 122: Third side

[0051] 123: Fourth side

[0052] 200: Projection device

[0053] 210: Shell

[0054] 211: Opening

[0055] 220: Lighting System

[0056] 230: Light valve

[0057] 240: Lens assembly

[0058] 1120: Segmented structure

[0059] 1210: Kong Yuan

[0060] 1211: Rotary buffer structure

[0061] 1212: Annular top edge

[0062] 1213: Installation port

[0063] 1211a: Limiting part

[0064] 1211b: Cantilever section

[0065] 1213a: Hook section

[0066] A: Optical axis

[0067] B: Ring-shaped base

[0068] C: Center

[0069] CA: Clamping Zone

[0070] D1: Zhou Xiang

[0071] D2: Radial

[0072] GS: Guide ramp

[0073] H1: Limiting hole

[0074] H2: Perforation

[0075] IR: inner diameter

[0076] IS1: Inner ring surface

[0077] IS2: Inner side

[0078] L: Lens

[0079] L1: illumination beam

[0080] L2: Image Beam

[0081] O1: First opening

[0082] O2: Second opening

[0083] O3: Third opening

[0084] O4: Fourth opening

[0085] OR2, OR1: outer diameter

[0086] OS1: Outer Ring

[0087] OS2: Outer side

[0088] S1: First side

[0089] S2: Second side

[0090] SE: Locking firmware

[0091] SE1: Shaft

[0092] SE2: Head

[0093] T: Thickness

[0094] TA: Passage Area

[0095] Z: Region.

Claims

1. A focusing module, characterized in that, The focusing module is used for lenses with an optical axis, and the focusing module includes a focusing ring and a lens mounting ring, wherein: The focusing ring has a first ring body and a first annular wall. The first ring body has a first opening and a second opening opposite to each other. The first annular wall is connected to the first ring body and surrounds the first opening. The first annular wall has a limiting hole, an inner annular surface, and an outer annular surface. The inner annular surface and the outer annular surface are opposite to each other, and the limiting hole penetrates the inner annular surface and the outer annular surface of the first annular wall in a direction perpendicular to the optical axis. The lens mounting ring has a second annular wall for fixing to the lens along the optical axis. The second annular wall is disposed inside the first annular wall and is for rotating relative to the first annular wall in the circumferential direction. The second annular wall has a perforation and a rotation buffer structure. The rotation buffer structure is located in the perforation and has a limiting portion and a cantilever portion. The cantilever portion connects the limiting portion and the edge of the perforation. The limiting portion has a center surrounded by the edge of the perforation. The center protrudes toward the first annular wall facing the focusing ring and has opposing first and second sides in the circumferential direction. In the radial direction of the second annular wall, the thickness of the limiting portion gradually decreases from the center toward the first side and toward the second side. When the limiting part of the rotating buffer structure abuts against the limiting hole of the focusing ring, the center of the limiting part is located inside the limiting hole and the first annular wall presses against the first side and the second side.

2. The focusing module according to claim 1, characterized in that, The first side and the second side of the center of the limiting part each have a guide slope.

3. The focusing module according to claim 2, characterized in that, The guide ramps are connected to each other and surround the center of the limiting portion.

4. The focusing module according to claim 1, characterized in that, The first annular wall of the focusing ring surrounds the outer side of the second annular wall with the optical axis as the center, and the inner annular surface of the first annular wall faces the second annular wall. When the focusing ring rotates with the optical axis as the center, the limiting hole of the focusing ring presses against the limiting part of the rotating buffer structure, so that the lens mounting ring rotates synchronously with the focusing ring.

5. The focusing module according to claim 4, characterized in that, When the cantilever portion of the rotating buffer structure of the lens mounting ring elastically deforms away from the inner ring surface and the center of the limiting portion leaves the limiting hole, the center of the limiting portion presses against the inner ring surface of the first annular wall of the focusing ring, causing the focusing ring to rotate relative to the lens mounting ring.

6. The focusing module according to claim 5, characterized in that, The inner annular surface of the first annular wall of the focusing ring has a plurality of segmented structures, which are spaced apart from each other, arranged along the circumferential direction, and correspond to the center of the limiting portion.

7. The focusing module according to claim 1, characterized in that, The number of limiting holes includes multiple holes, and the number of through holes corresponds to the number of limiting holes. The multiple limiting holes and the multiple through holes are equidistant from each other in the circumferential direction.

8. The focusing module according to claim 1, characterized in that, The second annular wall of the lens mounting ring is used to lock onto the lens via a plurality of fasteners along a direction perpendicular to the optical axis. Each of the plurality of fasteners has a shaft portion and a head. The second annular wall also has an inner side surface, an outer side surface, an annular top edge, and a plurality of mounting openings. The annular top edge connects the inner side surface and the outer side surface. Each of the plurality of mounting openings extends through the inner side surface and the outer side surface along a direction perpendicular to the optical axis and extends to the annular top edge along a direction parallel to the optical axis. Each of the plurality of mounting openings has two opposing hook portions. A clamping area and a channel area are formed between the two hook portions. The channel area communicates with the clamping area along a direction parallel to the optical axis and extends to the annular top edge. When the lens mounting ring is assembled onto the lens along the optical axis, the two hook portions in each of the plurality of mounting openings are deformed to allow the shaft portion to pass through the channel area and be fixed in the clamping area.

9. The focusing module according to claim 1, characterized in that, The lens mounting ring also has a third opening and a fourth opening, the third opening and the fourth opening being located on opposite sides of the second annular wall and the second annular wall surrounding the third opening and the fourth opening. The fourth opening is used for mounting the lens. The second annular wall has a third side near the third opening and a fourth side near the fourth opening. The outer diameter of the second annular wall on the fourth side is smaller than the inner diameter of the first opening, and the outer diameter of the second annular wall on the third side is larger than the inner diameter of the first opening.

10. The focusing module according to claim 1, characterized in that, The two opposite ends of the cantilever portion of the rotating buffer structure are respectively connected to the limiting portion and the edge of the through hole, and the cantilever portion and the limiting portion are arranged along a direction parallel to the optical axis.

11. A projection device, characterized in that, The projection device includes a housing, an illumination system, a light valve, and a lens assembly. The illumination system is disposed within the housing and provides an illumination beam. The light valve is disposed within the housing and located in the transmission path of the illumination beam from the illumination system to convert the illumination beam into an image beam. The housing has an opening. The lens assembly is disposed within the opening and located in the transmission path of the image beam from the light valve to project the image beam out of the projection device. The lens assembly includes a lens and a focusing module. The lens has an optical axis, and the focusing module is connected to the lens. The focusing module includes a focusing ring and a lens mounting ring. The focusing ring has a first ring body and a first annular wall. The first ring body has a first opening and a second opening opposite to each other. The first annular wall is connected to the first ring body and surrounds the first opening. The first annular wall has a limiting hole, an inner annular surface, and an outer annular surface. The inner annular surface and the outer annular surface are opposite to each other, and the limiting hole penetrates the inner annular surface and the outer annular surface of the first annular wall along a direction perpendicular to the optical axis. The lens mounting ring has a second annular wall for fixing to the lens along the optical axis. The second annular wall is disposed inside the first annular wall and is for rotating relative to the first annular wall in the circumferential direction. The second annular wall has a perforation and a rotation buffer structure. The rotation buffer structure is located in the perforation and has a limiting portion and a cantilever portion. The cantilever portion connects the limiting portion and the edge of the perforation. The limiting portion has a center surrounded by the edge of the perforation. The center protrudes toward the first annular wall facing the focusing ring and has opposing first and second sides in the circumferential direction. In the radial direction of the second annular wall, the thickness of the limiting portion gradually decreases from the center toward the first side and toward the second side. When the limiting part of the rotating buffer structure abuts against the limiting hole of the focusing ring, the center of the limiting part is located inside the limiting hole and the first annular wall presses against the first side and the second side.

12. The projection device according to claim 11, characterized in that, The first side and the second side of the center of the limiting part each have a guide slope.

13. The projection device according to claim 12, characterized in that, The guide ramps are connected to each other and surround the center of the limiting portion.

14. The projection device according to claim 11, characterized in that, The first annular wall of the focusing ring surrounds the outer side of the second annular wall with the optical axis as the center, and the inner annular surface of the first annular wall faces the second annular wall. When the focusing ring rotates with the optical axis as the center, the limiting hole of the focusing ring presses against the limiting part of the rotating buffer structure, so that the lens mounting ring rotates synchronously with the focusing ring.

15. The projection device according to claim 14, characterized in that, When the cantilever portion of the rotating buffer structure of the lens mounting ring elastically deforms away from the inner ring surface and the center of the limiting portion leaves the limiting hole, the center of the limiting portion presses against the inner ring surface of the first annular wall of the focusing ring, causing the focusing ring to rotate relative to the lens mounting ring.

16. The projection device according to claim 15, characterized in that, The inner annular surface has a plurality of segmented structures, which are spaced apart from each other and arranged along the circumferential direction and correspond to the center of the limiting part.

17. The projection device according to claim 11, characterized in that, The number of limiting holes includes multiple holes, and the number of through holes corresponds to the number of limiting holes. The multiple limiting holes and the multiple through holes are equidistant from each other in the circumferential direction.

18. The projection device according to claim 11, characterized in that, It also includes a plurality of locking fasteners, wherein the second annular wall of the lens mounting ring is locked to the lens via the plurality of locking fasteners in a direction perpendicular to the optical axis. Each of the plurality of locking fasteners has a shaft portion and a head. The second annular wall also has an inner side surface, an outer side surface, an annular top edge, and a plurality of mounting openings. The annular top edge is connected between the inner side surface and the outer side surface. Each of the plurality of mounting openings extends through the inner side surface and the outer side surface in a direction perpendicular to the optical axis and extends to the annular top edge in a direction parallel to the optical axis. Each of the plurality of mounting openings is provided with two opposing hook portions. A clamping area and a channel area are formed between the two hook portions. The channel area communicates with the clamping area in a direction parallel to the optical axis and extends to the annular top edge. When the lens mounting ring is assembled to the lens along the optical axis direction, the two hook portions in each of the plurality of mounting openings are used to deform so that the shaft portion passes through the channel area and is fixed in the clamping area.

19. The projection device according to claim 11, characterized in that, The lens mounting ring also has a third opening and a fourth opening, the third opening and the fourth opening being located on opposite sides of the second annular wall and the second annular wall surrounding the third opening and the fourth opening. The fourth opening is used for mounting the lens. The second annular wall has a third side near the third opening and a fourth side near the fourth opening. The outer diameter of the second annular wall on the fourth side is smaller than the inner diameter of the first opening, and the outer diameter of the second annular wall on the third side is larger than the inner diameter of the first opening.

20. The projection device according to claim 11, characterized in that, The two opposite ends of the cantilever portion of the rotating buffer structure are respectively connected to the limiting portion and the edge of the through hole, and the cantilever portion and the limiting portion are arranged along a direction parallel to the optical axis.

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