Focusing module and projector
By designing a focus module with a stop structure in the projector, limiting the rotation stroke of the relay gear, the screen jump and structural loss problems in the limit position of the focus module are solved, and the stability and durability are improved.
Patent Information
- Application Number
- CN202310754805.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-26
- Publication Date
- 2024-12-27
AI Technical Summary
When the focus module of existing projectors is in the limit position, the motor output force causes the lens module to jump or displace, and may cause structural losses.
A focus module is designed, including a bracket, a driving unit, a relay gear and a stop structure. The second maximum rotation stroke of the relay gear is smaller than the first maximum rotation stroke of the focus ring, and the stop structure limits the relay gear. Rotate to avoid the output force of the drive unit acting on the lens module.
It effectively avoids jumping or displacement of the projected image of the lens module, and reduces structural losses caused by the focus module under reaction force.
Smart Images
Figure CN119200304A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an optical device and a focusing module thereof, in particular to a projector and a focusing module thereof. Background Art
[0002] A projector is generally provided with a focus module, which uses a motor to drive the focus ring on the lens module to rotate and adjust the lens module. As for the external focus module, it is not set in the lens module, so when the motor of the focus module drives the focus ring to rotate to the limit position and the user fails to stop the motor output in time, the output force provided by the motor to the focus ring will act on the lens module like a thrust, causing the image projected by the lens module to jump or shift. In addition, if the motor continues to provide output force to the focus ring after the focus ring reaches the limit position for a long time, the reaction force borne by the focus module may cause structural damage to the focus module.
[0003] The "background technology" section is only used to help understand the content of the present invention. Therefore, the content disclosed in the "background technology" section may contain some known technologies that are not known to those skilled in the art. The content disclosed in the "background technology" section does not mean that the content or the problems to be solved by one or more embodiments of the present invention have been known or recognized by those skilled in the art before the application of the present invention. Summary of the invention
[0004] The invention provides a focus adjustment module and a projector, which can prevent the driving force of the focus adjustment module from causing the projection picture to shake.
[0005] Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the present invention.
[0006] To achieve one or part or all of the above purposes or other purposes, one embodiment of the present invention provides a focusing module suitable for a lens module. The lens module includes a focusing ring, which has a first maximum rotation stroke. The focusing ring is suitable for rotating to adjust the focal length of the lens module. The focusing module is connected to the focusing ring and includes a bracket, a driving unit, a relay gear, a first structure and a second structure. The driving unit is configured on the bracket. The relay gear is configured on the bracket and connected to the driving unit. The focusing ring is connected to the relay gear, and the driving unit is used to drive the relay gear to rotate to drive the focusing ring to rotate. The first structure is formed on the bracket. The second structure is formed on the relay gear. When the relay gear rotates relative to the bracket, the first structure and the second structure are suitable for stopping each other to limit the rotation of the relay gear, so that the relay gear has a second maximum rotation stroke, and the second maximum rotation stroke is smaller than the first maximum rotation stroke.
[0007] To achieve one or part or all of the above purposes or other purposes, one embodiment of the present invention provides a projector, including an illumination module, a light valve, a lens module and a focusing module. The illumination module is used to provide an illumination beam. The light valve is arranged on the transmission path of the illumination beam to convert the illumination beam into an image beam. The lens module is arranged on the transmission path of the image beam to project the image beam. The lens module includes a focusing ring, which has a first maximum rotation stroke, and the focusing ring is suitable for rotating to adjust the focal length of the lens module. The focusing module is connected to the focusing ring. The focusing module includes a bracket, a driving unit, a relay gear, a first structure and a second structure. The driving unit is arranged on the bracket. The relay gear is arranged on the bracket and connected to the driving unit. The focusing ring is connected to the relay gear, and the driving unit is used to drive the relay gear to rotate to drive the focusing ring to rotate. The first structure is formed on the bracket. The second structure is formed on the relay gear. When the relay gear rotates relative to the bracket, the first structure and the second structure are adapted to stop each other to limit the rotation of the relay gear so that the relay gear has a second maximum rotation stroke which is smaller than the first maximum rotation stroke.
[0008] Based on the above, the embodiments of the present invention have at least one of the following advantages or effects. In the focusing module of the embodiments of the present invention, the second structure on the relay gear and the first structure on the bracket can stop each other when the relay gear rotates relative to the bracket, so as to limit the maximum rotation stroke of the relay gear to be less than the maximum rotation stroke of the focusing ring. Accordingly, before the focusing ring rotates to its extreme position, the relay gear will first rotate to its extreme position to prevent the focusing ring from continuing to rotate, so as to prevent the output force provided by the drive unit to the focusing ring from acting on the lens module, causing the image projected by the lens module to jump or shift.
[0009] In order to make the above features and advantages of the present invention more clearly understood, embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 FIG. 4 is a schematic diagram of a projector according to an embodiment of the present invention.
[0011] Figure 2 yes Figure 1 A three-dimensional diagram of the partial structure of the projector.
[0012] Figure 3 yes Figure 2 A stereoscopic image of a lens module.
[0013] FIG. 4A to FIG. 4C According to Figure 2 A schematic diagram of a relay gear rotating to different states according to an embodiment of the present invention.
[0014] Figure 5FIG. 4 is a schematic diagram of some components of a focusing module according to another embodiment of the present invention.
[0015] Figure 6 is based on Figure 5 A stereogram of a relay gear.
[0016] Figure 7 is based on Figure 5 A three-dimensional diagram of the bracket and the drive unit.
[0017] FIG. 8A to FIG. 8C According to Figure 5 Schematic diagram of the relay gear rotating to different states.
[0018] Fig. 9 FIG. 4 is a schematic diagram of some components of a focusing module according to another embodiment of the present invention.
[0019] Fig.10 is based on Fig. 9 A stereogram of a relay gear.
[0020] Fig.11 is based on Fig. 9 A three-dimensional diagram of the bracket and the drive unit.
[0021] Description of Reference Numerals
[0022] 10: Projector
[0023] 12: Lighting module
[0024] 14: Light valve
[0025] 16: Lens module
[0026] 16a: Mirror tube
[0027] 16c: Focus ring
[0028] 16d: Main body
[0029] 100: Focus module
[0030] 110, 110A, 110B: Bracket
[0031] 120, 120A, 120B: Drive unit
[0032] 130, 130A, 130B: Relay gear
[0033] 131: Tooth area
[0034] 132: Non-tooth area
[0035] 140, 140A, 140B: First structure
[0036] 150, 150A, 150B: Second structure
[0037] 160: Driven gear
[0038] α: Maximum rotation angle
[0039] A: Axial
[0040] B: Stop surface
[0041] L1: illumination beam
[0042] L2: Image beam
[0043] P1, P2, P3, P4: Limiting columns
[0044] S1, S2, S3: limit slots. DETAILED DESCRIPTION
[0045] The above and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front or back, etc., are only the directions with reference to the accompanying drawings. Therefore, the directional terms used are used to illustrate and not to limit the present invention. In addition, the "connection" mentioned in the following embodiments includes the meanings of "direct connection" and "indirect connection".
[0046] Figure 1 is a schematic diagram of a projector according to an embodiment of the present invention. Figure 1 The projector 10 of this embodiment includes an illumination module 12, a light valve 14, a lens module 16 and a focus module 100. The illumination module 12 is used to provide an illumination beam L1. The light valve 14 is disposed on the transmission path of the illumination beam L1 to convert the illumination beam L1 into an image beam L2. The lens module 16 is disposed on the transmission path of the image beam L2 to project the image beam L2. The focus module 100 is applicable to the lens module 16 to drive the lens module 16 to adjust the focal length and limit the focus range of the lens module 16.
[0047] Figure 2 yes Figure 1 A three-dimensional diagram of the partial structure of the projector. Figure 3 yes Figure 2 Please refer to the stereogram of the lens module. Figure 2 and Figure 3The lens module 16 of this embodiment includes a lens barrel 16a, a lens assembly (not shown), a focus ring 16c and a main body 16d. The lens barrel 16a is disposed in the main body 16d, the lens assembly is disposed in the lens barrel 16a, and the focus ring 16c is sleeved on the outer wall of the lens barrel 16a and can rotate relative to the lens barrel 16a. In addition, according to the rotatable range, the focus ring 16c has a first maximum rotation stroke. The focusing module 100 is connected to the focus ring 16c, and is used to drive the focus ring 16c to rotate relative to the main body 16d (or the lens barrel 16a) with the axial direction A (for example, the optical axis of the lens module 16) as the central axis. The rotation of the focus ring 16c can drive at least a part of the lens assembly to move along the axial direction A, thereby adjusting the focal length of the lens module 16.
[0048] Specifically, the focus module 100 of the present embodiment includes a bracket 110, a driving unit 120, a relay gear 130 and a driven gear 160. The driving unit 120 is, for example, a motor and is disposed on the bracket 110. The relay gear 130 is rotatably disposed on the bracket 110 and connected to the driving unit 120. The driven gear 160 is connected to the focus ring 16c in a manner of being fixed to the focus ring 16c, and the focus ring 16c can be connected to the relay gear 130 through the driven gear 160. In detail, the driven gear 160 is engaged with the relay gear 130, and the driving unit 120 is used to drive the relay gear 130 to rotate, so that the relay gear 130 drives the focus ring 16c to rotate through the driven gear 160.
[0049] FIG. 4A to FIG. 4C According to Figure 2 A schematic diagram of a relay gear rotating to different states according to an embodiment of the present invention. FIG. 4A to FIG. 4C The focusing module 100 of this embodiment further includes a first structure 140 and a second structure 150. The first structure 140 is formed on the bracket 110, and the second structure 150 is formed on the relay gear 130. When the relay gear 130 rotates relative to the bracket 110, the first structure 140 and the second structure 150 are adapted to Figure 4A and Figure 4C The two stoppers are arranged to limit the rotation of the relay gear 130, so that the relay gear 130 has a second maximum rotation stroke. The second maximum rotation stroke of the relay gear 130 is smaller than the first maximum rotation stroke of the focus ring 16c.
[0050] As described above, the second structure 150 on the relay gear 130 and the first structure 140 on the bracket 110 of the present embodiment can stop each other when the relay gear 130 rotates relative to the bracket 110, so as to limit the maximum rotation stroke of the relay gear 130 (i.e., the second maximum rotation stroke) to be smaller than the maximum rotation stroke of the focus ring 16c (i.e., the first maximum rotation stroke). Accordingly, before the focus ring 16c rotates to its limit position, the relay gear 130 will first rotate to its limit position to prevent the focus ring 16c from continuing to rotate, so as to prevent the output force provided by the drive unit 120 to the focus ring 16c from acting on the lens module 16 and causing the image projected by the lens module 16 to jump or shift. In addition, the output force can be prevented from acting on the lens module 16 to generate a reaction force on the focus module 100, so that the focus module 100 will not be damaged due to repeated exposure to the reaction force for a long time.
[0051] Please refer to Figure 3 In this embodiment, the focus ring 16c has a limit groove S1 (three are shown), and the lens barrel 16a has a limit post P1 (three are shown), and the limit post P1 is located in the limit groove S1. The two opposite ends of the limit groove S1 are used to stop the limit post P1. That is, when either of the two opposite ends of the limit groove S1 contacts the limit post P1 as the focus ring 16c rotates, the focus ring 16c is located at its limit position. Therefore, according to the change in the relative position of the limit post P1 and the limit groove S1, the range of rotation of the focus ring 16c is provided, and the focus ring 16c is limited to have the first maximum rotation stroke. In detail, since the limit column P1 and the limit slot S1 will stop each other, the focus ring 16c has a maximum rotation angle α, which is the angle between the two opposite ends of the limit slot S1 and the axial direction A (for example, the optical axis of the lens module 16), and the first maximum rotation stroke is the distance moved by the focus ring 16c at the maximum rotation angle α. For example, if the maximum rotation angle α of the focus ring 16c is 60 degrees, the first maximum rotation stroke is the moving distance of the focus ring 16c rotating 60 degrees, that is, πr / 3, where r is the radius of the focus ring 16c. In addition, since the second maximum rotation stroke of the relay gear 130 is smaller than the first maximum rotation stroke of the focus ring 16c, the second maximum rotation stroke of the relay gear 130 can be designed according to the maximum rotation angle α of the focus ring 16c. For example, when the maximum rotation angle α of the focus ring 16c is 60 degrees, the second maximum rotation stroke of the relay gear 130 can be designed as the moving distance of the focus ring 16c rotating 59 degrees. In other embodiments, the maximum rotation angle α can be other appropriate angles, and the second maximum rotation stroke can be the moving distance of the focus ring 16c slightly smaller than the maximum rotation angle α, and the present invention is not limited thereto.
[0052] Please refer to FIG. 4A to FIG. 4C, the first structure 140 of this embodiment includes at least one limiting post P2 (two are shown) formed on the bracket 110. The relay gear 130 has a toothed area 131 and a non-toothed area 132. The toothed area 131 is meshed with the driven gear 160 and connected to the focus ring 16c through the driven gear 160. The non-toothed area 132 has two stop surfaces B to form a second structure 150. The two limiting posts P2 are respectively located on the rotation paths of the two stop surfaces B. The two stop surfaces B are respectively used to stop the two limiting posts P2 to limit the relay gear 130 to have the second maximum rotation stroke. In detail, corresponding to Figure 4A In the rotation state shown in FIG. 1 , since one of the limit posts P2 and one of the stop surfaces B stop each other, the relay gear 130 is at its limit position, so that the relay gear 130 can no longer rotate counterclockwise and can only rotate clockwise. Figure 4B When the relay gear 130 is in the state of being stopped, the limit post P2 and the stop surface B do not stop each other, and the relay gear 130 can rotate in the clockwise or counterclockwise direction at will. Figure 4C When the relay gear 130 is in the state of being stopped, the other limit post P2 and the other stop surface B stop each other, so that the relay gear 130 is located at its other limit position. The relay gear 130 can no longer rotate in the clockwise direction, but can only rotate in the counterclockwise direction. Figure 4A Status rotates to Figure 4C Status or Figure 4C Status rotates to Figure 4A The moving distance of the state is the second maximum rotation stroke. According to the change in the relative position of the limit column P2 and the stop surface B, the amplitude by which the relay gear 130 can be rotated is provided, and the relay gear 130 is limited to have the second maximum rotation stroke. It should be noted that the clockwise and counterclockwise rotation described here are only used to distinguish different rotation directions, and are not used to limit the actual operation of the component rotation. In addition, although two limit columns are used for illustration in this embodiment, in other embodiments, there can be only one limit column, and the two stop surfaces B are used to stop on opposite sides of the limit column to limit the relay gear 130 to have the second maximum rotation stroke.
[0053] The present invention does not limit the forms of the first structure and the second structure, which are described below with examples.
[0054] Figure 5 FIG. 4 is a schematic diagram of some components of a focusing module according to another embodiment of the present invention. Figure 6 is based on Figure 5 A stereogram of a relay gear. Figure 7 is based on Figure 5 A three-dimensional diagram of the bracket and the drive unit. FIG. 8A to FIG. 8C According to Figure 5Schematic diagram of the relay gear rotating to different states. Figures 5 to 8C In the illustrated embodiment, the configuration and mode of action of the bracket 110A, the drive unit 120A, the relay gear 130A, the first structure 140A, and the second structure 150A are similar to the configuration and mode of action of the bracket 110, the drive unit 120, the relay gear 130, the first structure 140, and the second structure 150 of the aforementioned embodiment. Figures 5 to 8C The embodiment shown is different from the previous embodiment in that: Figures 5 to 8C The first structure 140A shown includes an arc-shaped limiting groove S2 formed on the bracket 110A, and the second structure 150A includes at least one limiting column P3 (shown as one) formed on the relay gear 130A. The limiting column P3 is located in the limiting groove S2, and the two opposite ends of the limiting groove S2 are used to stop the limiting column P3 to limit the relay gear 130A to have a second maximum rotation stroke. That is, Fig. 8A or Figure 8C As shown in FIG. 1 , when the limiting post P3 contacts any of the two opposite ends of the limiting slot S2 as the relay gear 130A rotates, the relay gear 130A is located at its limit position. Fig. 8A Status rotates to Figure 8C Status or Figure 8C Status rotates to Fig. 8A The moving distance of the state is the second maximum rotation stroke. According to the change of the position of the limiting column P3 in the limiting groove S2, the amplitude of the relay gear 130A that can be rotated is provided, and the relay gear 130A is limited to have the second maximum rotation stroke.
[0055] Fig. 9 FIG. 4 is a schematic diagram of some components of a focusing module according to another embodiment of the present invention. Fig.10 is based on Fig. 9 A stereogram of a relay gear. Fig.11 is based on Fig. 9 A three-dimensional diagram of the bracket and drive unit. Figures 9 to 11 In the illustrated embodiment, the configuration and mode of action of the bracket 110B, the drive unit 120B, the relay gear 130B, the first structure 140B, and the second structure 150B are similar to the configuration and mode of action of the bracket 110A, the drive unit 120A, the relay gear 130A, the first structure 140A, and the second structure 150A of the aforementioned embodiment. Figures 9 to 11 The embodiment shown is different from the previous embodiment in that: Figures 9 to 11The first structure 140B shown includes at least one limiting column P4 (shown as one) formed on the bracket 110B, and the second structure 150B includes an arc-shaped limiting groove S3 formed on the relay gear 130B. The limiting column P4 is located in the limiting groove S3, and the two opposite ends of the limiting groove S3 are used to stop the limiting column P4, so as to limit the relay gear 130B to have the second maximum rotation stroke. In detail, according to the change of the position of the limiting column P4 in the limiting groove S3, the amplitude of the relay gear 130B that can be rotated is provided, and the relay gear 130B is limited to have the second maximum rotation stroke.
[0056] In the projector according to the embodiment of the present invention, since the focus module is connected to the focus ring of the lens module, when the driving unit of the focus module is actuated, the relay gear can be driven to rotate, thereby driving the focus ring of the lens module to rotate, so as to adjust the focal length of the lens module. At the same time, since the second maximum rotation stroke of the relay gear is smaller than the first maximum rotation stroke of the focus ring, before the focus ring reaches its limit position, the relay gear will first rotate to its limit position and prevent the focus ring from continuing to rotate.
[0057] In summary, the embodiments of the present invention have at least one of the following advantages or effects. In the focusing module of the embodiments of the present invention, the second structure on the relay gear and the first structure on the bracket can stop each other when the relay gear rotates relative to the bracket, so as to limit the maximum rotation stroke of the relay gear to be less than the maximum rotation stroke of the focusing ring. Accordingly, before the focusing ring rotates to its extreme position, the relay gear will first rotate to its extreme position to prevent the focusing ring from continuing to rotate, so that the excess output force from the driving unit is borne on the relay gear, so as to avoid the output force provided by the driving unit to the focusing ring from acting on the lens module, causing the picture projected by the lens module to jump or shift. In addition, it can be avoided that the output force provided by the focusing module acts on the lens module to generate a reaction force on the focusing module, so that the focusing module will not be damaged due to repeated exposure to the reaction force for a long time.
[0058] The above description is only the preferred embodiment of the present invention, and it cannot be used to limit the scope of the implementation of the present invention. That is, all simple equivalent changes and modifications made according to the claims and the description of the present invention are still within the scope of the patent coverage of the present invention. In addition, any embodiment or claim of the present invention does not need to achieve all the purposes, advantages or features disclosed in the present invention. In addition, the abstract of the specification and the name of the invention are only used to assist in the retrieval of patent documents, and are not used to limit the scope of rights of the present invention. In addition, the terms "first", "second", etc. mentioned in this specification or claims are only used to name the name of the element or distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements.
Claims
1. A focusing module, applicable to a lens module, the lens module comprising a focusing ring, the focusing ring having a first maximum rotation stroke, the focusing ring being adapted to rotate to adjust the focal length of the lens module, the focusing module being connected to the focusing ring, characterized in that: The focusing module includes a bracket, a driving unit, a relay gear, a first structure and a second structure. The driving unit is configured on the bracket; The relay gear is disposed on the bracket and connected to the driving unit, wherein the focus ring is connected to the relay gear, and the driving unit is used to drive the relay gear to rotate so as to drive the focus ring to rotate; The first structure is formed on the bracket; The second structure is formed on the relay gear, wherein when the relay gear rotates relative to the bracket, the first structure and the second structure are suitable for stopping each other to limit the rotation of the relay gear, so that the relay gear has a second maximum rotation stroke, and the second maximum rotation stroke is smaller than the first maximum rotation stroke.
2. The focusing module according to claim 1, characterized in that: The first structure includes at least one limit column formed on the bracket, the relay gear has a tooth area and a non-tooth area, the tooth area is connected to the focusing ring, and the non-tooth area has two stop surfaces to form the second structure, the at least one limit column is located on the rotation path of the two stop surfaces, and the two stop surfaces are used to stop the at least one limit column to limit the relay gear to have the second maximum rotation stroke.
3. The focusing module according to claim 2, characterized in that: The number of the at least one limiting column is two.
4. The focusing module according to claim 1, characterized in that: The first structure includes a limit groove formed on the bracket, and the second structure includes at least one limit column formed on the relay gear, the at least one limit column is located in the limit groove, and the opposite ends of the limit groove are used to stop the at least one limit column to limit the relay gear to have the second maximum rotation stroke.
5. The focusing module according to claim 4, characterized in that: The limiting groove is arc-shaped.
6. The focusing module according to claim 1, characterized in that: The first structure includes at least one limiting column formed on the bracket, and the second structure includes a limiting groove formed on the relay gear. The at least one limiting column is located in the limiting groove, and the opposite ends of the limiting groove are used to stop the at least one limiting column to limit the relay gear to have the second maximum rotation stroke.
7. The focusing module according to claim 6, characterized in that: The limiting groove is arc-shaped.
8. The focusing module according to claim 1, characterized in that: A driven gear is also included, wherein the driven gear is connected to the focus ring and meshed with the relay gear.
9. The focusing module according to claim 1, characterized in that: The first maximum rotation stroke is the distance that the focus ring moves at the maximum rotation angle, and the maximum rotation angle is 60 degrees.
10. A projector, characterized in that: Including lighting module, light valve, lens module and focusing module, The lighting module is used to provide a lighting beam; The light valve is disposed on the transmission path of the illumination light beam, and is used to convert the illumination light beam into an image light beam; The lens module is disposed on the transmission path of the image beam to project the image beam, wherein the lens module comprises a focus ring having a first maximum rotation stroke, and the focus ring is suitable for rotating to adjust the focal length of the lens module; The focusing module is connected to the focusing ring, and the focusing module includes a bracket, a driving unit, a relay gear, a first structure and a second structure. The driving unit is configured on the bracket; The relay gear is disposed on the bracket and connected to the driving unit, wherein the focus ring is connected to the relay gear, and the driving unit is used to drive the relay gear to rotate so as to drive the focus ring to rotate; The first structure is formed on the bracket; The second structure is formed on the relay gear, wherein when the relay gear rotates relative to the bracket, the first structure and the second structure are suitable for stopping each other to limit the rotation of the relay gear, so that the relay gear has a second maximum rotation stroke, and the second maximum rotation stroke is smaller than the first maximum rotation stroke.
11. The projector according to claim 10, characterized in that: The first structure includes at least one limit column formed on the bracket, the relay gear has a tooth area and a non-tooth area, the tooth area is connected to the focusing ring, and the non-tooth area has two stop surfaces to form the second structure, the at least one limit column is located on the rotation path of the two stop surfaces, and the two stop surfaces are used to stop the at least one limit column to limit the relay gear to have the second maximum rotation stroke.
12. The projector according to claim 11, characterized in that The number of the at least one limiting column is two.
13. The projector according to claim 10, characterized in that: The first structure includes a limit groove formed on the bracket, and the second structure includes at least one limit column formed on the relay gear, the at least one limit column is located in the limit groove, and the opposite ends of the limit groove are used to stop the at least one limit column to limit the relay gear to have the second maximum rotation stroke.
14. The projector according to claim 13, characterized in that: The limiting groove is arc-shaped.
15. The projector according to claim 10, characterized in that: The first structure includes at least one limiting column formed on the bracket, and the second structure includes a limiting groove formed on the relay gear. The at least one limiting column is located in the limiting groove, and the opposite ends of the limiting groove are used to stop the at least one limiting column to limit the relay gear to have the second maximum rotation stroke.
16. The projector according to claim 15, characterized in that The limiting groove is arc-shaped.
17. The projector according to claim 10, characterized in that: The focus module further includes a driven gear connected to the focus ring and meshed with the relay gear.
18. The projector according to claim 10, characterized in that: The lens module includes a lens barrel, the focus ring is sleeved on the outer wall of the lens barrel, the focus ring has a limit groove, the lens barrel has a limit column, the limit column is located in the limit groove, and the opposite ends of the limit groove are used to stop the limit column to limit the focus ring to have the first maximum rotation stroke.
19. The projector according to claim 10, characterized in that The first maximum rotation stroke is the distance that the focus ring moves at the maximum rotation angle, and the maximum rotation angle is 60 degrees.