Zero-return-difference zoom compensation lens group driving device with stable pre-tightening force

Abstract

The utility model discloses a zero-return-difference zoom compensation lens group driving device with stable pre-tightening force, which belongs to the technical field of cam transmission and comprises a zoom lens group, a compensation lens group, a linear guide rail pair, a cam shaft and a U-shaped spring assembly. The zoom lens group and the compensating lens group are mounted on the linear guide rail pair, and the linear guide rail pair limits the zoom lens group and the compensating lens group to only move along a straight line; driving force is applied to the zoom lens group and the compensating lens group through the cam shaft, and the cam shaft drives the zoom lens group and the compensating lens group to move back and forth along the linear guide rail pair when rotating forwards or backwards; the stable pre-tightening force is applied to the zoom lens group and the compensation lens group through the U-shaped spring assembly, so that the zoom lens group and the compensation lens group are always in contact with the same groove surface of the respective cam groove. The utility model is mainly applied to the design and manufacture of zoom optical lenses, and has the characteristics of compact structure, easy processing, and simple installation and adjustment.

Description

Technical Field

[0001] This utility model belongs to the field of cam transmission technology and is mainly applied to the design and manufacturing of zoom optical lenses. In particular, it relates to a zero backlash zoom compensation lens group drive device with stable preload. Background Technology

[0002] In the design and manufacturing process of zoom optical lenses, zoom is generally achieved by driving the zoom lens group and the compensation lens group to move along the predetermined axial displacement according to the optical design through a zoom cam (cam cylinder or camshaft). During the movement, the positioning requirements of the zoom lens group and the compensation lens group are very high, such as at the 10-micron level. Therefore, it is necessary to reduce or eliminate the backlash in the zoom compensation lens group drive device to improve the positioning accuracy, thereby ensuring the imaging quality of the zoom optical lens.

[0003] The zoom cam's cam groove is fitted with the zoom lens group and the compensating lens group with a clearance to ensure that it is not stuck during movement. However, the clearance produces backlash, which affects the positioning accuracy.

[0004] Existing technology uses two tension or compression springs to separately pull the zoom lens assembly and the compensating lens assembly, ensuring that the zoom lens assembly and the compensating lens assembly are always close to the same side of the zoom cam groove and the compensating cam groove on the camshaft, respectively, to eliminate the backlash of the mechanism. Its shortcomings are:

[0005] First, whether it is a tension spring or a compression spring, its extension length or compression length is limited, and the extension length or compression length must be greater than the movement stroke of the mirror assembly; therefore, the shortest length of the tension spring or compression spring also increases, resulting in an increase in the space volume required for the spring assembly, which is not conducive to miniaturization.

[0006] Second, the greater the stretching or compression length, the greater the difference between the maximum and minimum elastic forces of the spring, which leads to a greater difference in the driving torque required at both ends of the motion stroke of the zoom lens group and the compensating lens group. In other words, the torque required for full-stroke drive varies greatly, which increases the difficulty of servo control and positioning instability.

[0007] Third, when the drive device is at the minimum elasticity end, it can stop due to the motor being de-energized. However, when it is at the maximum elasticity end, the drive device needs the motor to be energized to control and stabilize the position of the mirror assembly. This increases the upper limit of the required torque of the drive motor, which is not conducive to the miniaturization of the drive device. Utility Model Content

[0008] To eliminate the mating gap in the zoom compensation lens group drive device of a zoom optical lens, improve the positioning accuracy of the zoom lens group and the compensation lens group, and achieve zero backlash, this utility model provides a zero backlash zoom compensation lens group drive device with stable preload, comprising: zoom lens group 1, compensation lens group 2, linear guide pair 3, camshaft 4, and U-shaped spring assembly 5; zoom lens group 1 and compensation lens group 2 are mounted on the linear guide pair 3, which restricts the zoom lens group 1 and compensation lens group 2 to only move in a straight line; driving force is applied to zoom lens group 1 and compensation lens group 2 through camshaft 4, and when camshaft 4 rotates in the forward or reverse direction, it drives zoom lens group 1 and compensation lens group 2 to move back and forth along the linear guide pair 3; stable preload is applied to zoom lens group 1 and compensation lens group 2 through U-shaped spring assembly 5, so that zoom lens group 1 and compensation lens group 2 are always in contact with the same groove surface of their respective cam grooves.

[0009] Furthermore, the aforementioned zoom lens assembly 1 comprises a zoom lens 1-1, a zoom lens frame 1-2, a bearing 1-3, a shaft retaining ring 1-4, a first zoom lens frame pad 1-5, and a second zoom lens frame pad 1-6. The zoom lens 1-1 is mounted in the zoom lens frame 1-2. The bearing 1-3 is fixed to the zoom lens frame 1-2 via the shaft retaining ring 1-4. The first zoom lens frame pad 1-5 and the second zoom lens frame pad 1-6 are mounted on the zoom lens frame 1-2 to adjust the optical axis height of the zoom lens 1-1. Simultaneously, the zoom lens frame 1-2 is mounted on the linear guide rail pair 3 via the two pads. The first zoom lens frame pad 1-5, the second zoom lens frame pad 1-6, and the zoom lens frame 1-2 can also be designed as an integrated unit.

[0010] Furthermore, the aforementioned compensating lens assembly 2 comprises a compensating lens 2-1, a compensating lens frame 2-2, a bearing 2-3, a shaft retaining ring 2-4, a first compensating lens frame pad 2-5, and a second compensating lens frame pad 2-6. The compensating lens 2-1 is installed in the compensating lens frame 2-2. The bearing 2-3 is fixed to the compensating lens frame 2-2 by the shaft retaining ring 2-4. The first compensating lens frame pad 2-5 and the second compensating lens frame pad 2-6 are installed on the compensating lens frame 2-2 to adjust the optical axis height of the compensating lens 2-1. At the same time, the two pads are used to install the compensating lens frame 2-2 on the linear guide rail pair 3. The first compensating lens frame pad 2-5, the second compensating lens frame pad 2-6, and the compensating lens frame 2-2 can also be designed as an integrated unit.

[0011] Furthermore, the linear guide pair 3 described above consists of a linear guide 3-1 and a slider 3-2; the slider 3-2 is mounted on the linear guide 3-1 and moves along a straight line; the slider 3-2 is respectively mounted with the zoom lens group 1 and the compensating lens group 2.

[0012] Furthermore, the aforementioned camshaft 4 includes a zoom cam groove 4-1 and a compensation cam groove 4-2. The two cam grooves apply driving force to bearing 1-3 and bearing 2-3 respectively, thereby driving the zoom lens group 1 and the compensation lens group 2 to move along the linear guide pair 3.

[0013] Furthermore, the aforementioned U-shaped spring assembly 5 consists of a compression spring 5-1, a spring guide rod 5-2, and a guide rod bracket 5-3. The spring guide rod 5-2 has a U-shaped structure. The spring guide rod 5-2 passes through the compression spring 5-1, the second zoom lens frame pad 1-6, and the second compensation lens frame pad 2-6 and is mounted on the guide rod bracket 5-3. The two ends of the compression spring 5-1 are respectively close to the second zoom lens frame pad 1-6 and the second compensation lens frame pad 2-6 and are compressed to provide preload, so that the bearing 1-3 and the bearing 2-3 are always close to the same side of the zoom cam groove 4-1 and the compensation cam groove 4-2, thereby eliminating the backlash of the drive device.

[0014] Furthermore, the zoom cam groove 4-1 and the compensation cam groove 4-2 in the aforementioned camshaft 4 are flattened into a figure-eight shape; when the camshaft 4 is driven to rotate, the zoom lens group 1 and the compensation lens group 2 move in opposite directions, that is, the two lens groups move in a motion form from both ends toward the middle or from the middle toward both ends; secondly, because the preload force borne by the zoom lens group 1 and the compensation lens group 2 is equal in magnitude and consistent in direction, the torque generated when they act on the camshaft 4 is opposite, making the camshaft 4 tend to be statically stable.

[0015] Furthermore, when the zoom lens group 1 and the compensating lens group 2 move closer to each other from both ends towards the middle, the zoom lens group 1 moves from left to right, compressing the compression spring 5-1 and increasing its elastic force. The compensating lens group 2 moves from right to left, releasing the compression spring 5-1 and decreasing its elastic force. This makes the preload of the drive device tend to stabilize. Similarly, when the zoom lens group 1 and the compensating lens group 2 move further apart from each other from the middle, the zoom lens group 1 moves from right to left, releasing the compression spring 5-1 and decreasing its elastic force. The compensating lens group 2 moves from left to right, compressing the compression spring 5-1 and increasing its elastic force. This makes the preload of the drive device tend to stabilize.

[0016] The beneficial effects of this utility model are:

[0017] (1) The use of the U-shaped spring assembly gives the two ends of the compression spring motion characteristics. That is, when one end of the compression spring is squeezed to increase the elastic force, the other end is relaxed to reduce the elastic force, thereby making the preload of the drive device tend to be stable.

[0018] (2) The preload forces on the zoom lens group and the compensating lens group are equal in magnitude and in the same direction, so that the torques they generate when acting on the camshaft are opposite, making the camshaft tend to be statically stable.

[0019] (3) The bearing one on the zoom lens assembly and the bearing two on the compensating lens assembly are always close to the same side of the zoom cam groove and the compensating cam groove, respectively, thereby eliminating the backlash of the mechanism and improving the positioning accuracy.

[0020] (4) This utility model has a compact structure, is easy to process, and is simple to assemble and adjust. Attached Figure Description

[0021] The following figures are for illustrative purposes only and are not intended to limit the scope of this invention.

[0022] Figure 1 This is a schematic diagram of the structure of a zero-backlash zoom compensation lens group drive device with stable pre-tightening force according to this utility model.

[0023] Figure 2 This is a schematic diagram of the variable cam groove and the compensation cam groove in the camshaft of this utility model, which are flattened into a figure-eight shape.

[0024] In the picture:

[0025] 1: Magnification lens assembly; 2: Compensation lens assembly; 3: Linear guide pair; 4: Camshaft; 5: U-shaped spring assembly;

[0026] 1-1: Zoom lens, 1-2: Zoom lens frame, 1-3: Bearing 1, 1-4: Shaft retaining ring 1, 1-5: First zoom lens frame pad, 1-6: Second zoom lens frame pad;

[0027] 2-1: Compensating lens; 2-2: Compensating lens frame; 2-3: Bearing II; 2-4: Shaft retainer II; 2-5: First compensating lens frame pad; 2-6: Second compensating lens frame pad;

[0028] 3-1: Linear guide rail; 3-2: Slider;

[0029] 4-1: Variable magnification cam groove; 4-2: Compensation cam groove;

[0030] 5-1: Compression spring; 5-2: Spring guide rod; 5-3: Guide rod bracket. Detailed Implementation

[0031] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.

[0032] This utility model provides a zero-backlash zoom compensation lens group drive device with stable preload, comprising: zoom lens group 1, compensation lens group 2, linear guide pair 3, camshaft 4, and U-shaped spring assembly 5; zoom lens group 1 and compensation lens group 2 are mounted on linear guide pair 3, which restricts zoom lens group 1 and compensation lens group 2 to only move in a straight line; driving force is applied to zoom lens group 1 and compensation lens group 2 through camshaft 4, and when camshaft 4 rotates in the forward or reverse direction, it drives zoom lens group 1 and compensation lens group 2 to move back and forth along linear guide pair 3; stable preload is applied to zoom lens group 1 and compensation lens group 2 through U-shaped spring assembly 5, so that zoom lens group 1 and compensation lens group 2 are always in contact with the same groove surface of their respective cam grooves.

[0033] In addition, the following requirements apply during implementation:

[0034] The aforementioned zoom lens assembly 1 comprises a zoom lens 1-1, a zoom lens frame 1-2, a bearing 1-3, a shaft retainer 1-4, a first zoom lens frame pad 1-5, and a second zoom lens frame pad 1-6. The zoom lens 1-1 is mounted in the zoom lens frame 1-2. The bearing 1-3 is fixed to the zoom lens frame 1-2 by the shaft retainer 1-4. The first zoom lens frame pad 1-5 and the second zoom lens frame pad 1-6 are mounted on the zoom lens frame 1-2 to adjust the optical axis height of the zoom lens 1-1. At the same time, the zoom lens frame 1-2 is mounted on the linear guide rail pair 3 by the two pads. The first zoom lens frame pad 1-5, the second zoom lens frame pad 1-6, and the zoom lens frame 1-2 can also be designed as an integrated unit.

[0035] The aforementioned compensating lens assembly 2 consists of a compensating lens 2-1, a compensating lens frame 2-2, a bearing 2-3, a shaft retaining ring 2-4, a first compensating lens frame pad 2-5, and a second compensating lens frame pad 2-6. The compensating lens 2-1 is installed in the compensating lens frame 2-2. The bearing 2-3 is fixed to the compensating lens frame 2-2 by the shaft retaining ring 2-4. The first compensating lens frame pad 2-5 and the second compensating lens frame pad 2-6 are installed on the compensating lens frame 2-2 to adjust the optical axis height of the compensating lens 2-1. At the same time, the two pads are used to install the compensating lens frame 2-2 on the linear guide rail pair 3. The first compensating lens frame pad 2-5, the second compensating lens frame pad 2-6, and the compensating lens frame 2-2 can also be designed as an integrated unit.

[0036] The linear guide rail assembly 3 described above consists of a linear guide rail 3-1 and a slider 3-2; the slider 3-2 is mounted on the linear guide rail 3-1 and moves along a straight line; the slider 3-2 is respectively equipped with a zoom lens assembly 1 and a compensating lens assembly 2.

[0037] The aforementioned camshaft 4 includes a zoom cam groove 4-1 and a compensation cam groove 4-2. The two cam grooves apply driving force to bearings 1-3 and 2-3 respectively, thereby driving the zoom lens group 1 and the compensation lens group 2 to move along the linear guide pair 3.

[0038] The aforementioned U-shaped spring assembly 5 consists of a compression spring 5-1, a spring guide rod 5-2, and a guide rod bracket 5-3. The spring guide rod 5-2 has a U-shaped structure. The spring guide rod 5-2 passes through the compression spring 5-1, the second zoom lens frame pad 1-6, and the second compensation lens frame pad 2-6 and is mounted on the guide rod bracket 5-3. The two ends of the compression spring 5-1 are respectively close to the second zoom lens frame pad 1-6 and the second compensation lens frame pad 2-6 and are compressed to provide preload, so that the bearing 1-3 and the bearing 2-3 are always close to the same side of the zoom cam groove 4-1 and the compensation cam groove 4-2, thereby eliminating the backlash of the drive device.

[0039] The zoom cam groove 4-1 and the compensation cam groove 4-2 in the camshaft 4 mentioned above are flattened into a figure-eight shape; when the camshaft 4 is driven to rotate, the zoom lens group 1 and the compensation lens group 2 move in opposite directions, that is, the two lens groups move in a motion form from both ends toward the middle or from the middle toward both ends; secondly, because the preload force borne by the zoom lens group 1 and the compensation lens group 2 is equal in magnitude and in the same direction, the torque generated when they act on the camshaft 4 is opposite, making the camshaft 4 tend to be statically stable.

[0040] When the zoom lens group 1 and the compensating lens group 2 move closer to each other from both ends toward the middle, the zoom lens group 1 moves from left to right, the compression spring 5-1 is squeezed, and the elastic force increases. When the compensating lens group 2 moves from right to left, the compression spring 5-1 is relaxed, and the elastic force decreases. In this way, the preload of the drive device tends to be stable. Similarly, when the zoom lens group 1 and the compensating lens group 2 move further apart from the middle, the zoom lens group 1 moves from right to left, the compression spring 5-1 is relaxed, and the elastic force decreases. When the compensating lens group 2 moves from left to right, the compression spring 5-1 is squeezed, and the elastic force increases. In this way, the preload of the drive device tends to be stable.

[0041] Example:

[0042] The structural schematic diagram of this utility model is shown below. Figure 1As shown. The zoom lens assembly 1 and the compensating lens assembly 2 are mounted on the linear guide pair 3 and can only move in a straight line; the two ends of the compression spring 5-1 are respectively close to the second zoom lens frame pad 1-6 and the second compensating lens frame pad 2-6, and are compressed to provide preload, so that the bearing 1-3 and the bearing 2-3 are always close to the same side of the zoom cam groove 4-1 and the compensating cam groove 4-2, thereby eliminating the backlash of the drive device; secondly, since the preload of the zoom lens assembly 1 and the compensating lens assembly 2 is equal in magnitude and consistent in direction, the torques they generate when acting on the camshaft 4 are opposite, making the camshaft 4 tend to be statically stable; when the camshaft 4 rotates clockwise in the positive direction of the arrow in the figure, When the zoom lens assembly 1 and the compensating lens assembly 2 move closer together from both ends to the middle, and the zoom lens assembly 1 moves from left to right, the compression spring 5-1 is compressed, increasing its elastic force, while the compensating lens assembly 2 moves from right to left, the compression spring 5-1 is relaxed, decreasing its elastic force. This stabilizes the preload of the drive device. Similarly, when the camshaft 4 rotates counterclockwise in the opposite direction of the arrow in the diagram, the zoom lens assembly 1 and the compensating lens assembly 2 move further apart from the middle, and the zoom lens assembly 1 moves from right to left, the compression spring 5-1 is relaxed, decreasing its elastic force, while the compensating lens assembly 2 moves from left to right, the compression spring 5-1 is compressed, increasing its elastic force. This stabilizes the preload of the drive device.

Claims

1. A zero-reticle variable power compensation lens group driving device with stable pre-tightening force, characterized in that, It comprises: a variable magnification lens group (1), a compensation lens group (2), a linear guide pair (3), a camshaft (4) and a U-shaped spring assembly (5); the variable magnification lens group (1) and the compensation lens group (2) are installed on the linear guide pair (3), and the linear guide pair (3) is used to limit the variable magnification lens group (1) and the compensation lens group (2) to only move along a straight line; the driving force is applied to the variable magnification lens group (1) and the compensation lens group (2) through the camshaft (4), and the camshaft (4) drives the variable magnification lens group (1) and the compensation lens group (2) to move back and forth along the linear guide pair (3) when it rotates forward or reversely; the stable pre-tightening force is applied to the variable magnification lens group (1) and the compensation lens group (2) through the U-shaped spring assembly (5), which is used to make the variable magnification lens group (1) and the compensation lens group (2) always contact with the same groove surface of the respective cam groove.

2. The zero-backlash variable magnification compensation lens group driving device with stable pre-tightening force according to claim 1, wherein: when the variable magnification lens group (1) and the compensation lens group (2) move towards the middle from both ends, the variable magnification lens group (1) moves from left to right, the compression spring (5-1) is squeezed to increase the spring force, and the compensation lens group (2) moves from right to left, the compression spring (5-1) is relaxed to reduce the spring force, which is used to make the pre-tightening force of the driving device tend to be stable.

3. The zero-backlash variable magnification compensation lens group driving device with stable pre-tightening force according to claim 1, wherein: when the variable magnification lens group (1) and the compensation lens group (2) move away from the middle to both ends, the variable magnification lens group (1) moves from right to left, the compression spring (5-1) is relaxed to reduce the spring force, and the compensation lens group (2) moves from left to right, the compression spring (5-1) is squeezed to increase the spring force, which is used to make the pre-tightening force of the driving device tend to be stable.

4. The zero-backlash variable magnification compensation lens group driving device with stable pre-tightening force according to any one of claims 1-3, wherein: the variable magnification lens group (1) is composed of a variable magnification lens (1-1), a variable magnification lens frame (1-2), a bearing one (1-3), a shaft ring one (1-4), a first variable magnification lens frame pad (1-5) and a second variable magnification lens frame pad (1-6); the variable magnification lens (1-1) is installed in the variable magnification lens frame (1-2); the bearing one (1-3) is fixed on the variable magnification lens frame (1-2) through the shaft ring one (1-4); the first variable magnification lens frame pad (1-5) and the second variable magnification lens frame pad (1-6) are installed on the variable magnification lens frame (1-2) to adjust the optical axis height of the variable magnification lens (1-1), and at the same time, the variable magnification lens frame (1-2) is installed on the linear guide pair (3) through the two pads; the first variable magnification lens frame pad (1-5), the second variable magnification lens frame pad (1-6) and the variable magnification lens frame (1-2) are designed integrally.

5. The zero-backlash variable magnification compensation lens group driving device with stable pre-tightening force according to claim 4, wherein: The compensation mirror group (2) is composed of a compensation lens (2-1), a compensation mirror frame (2-2), a bearing two (2-3), a shaft ring two (2-4), a first compensation mirror frame pad (2-5), and a second compensation mirror frame pad (2-6); the compensation lens (2-1) is installed in the compensation mirror frame (2-2); the bearing two (2-3) is fixed on the compensation mirror frame (2-2) through the shaft ring two (2-4); the first compensation mirror frame pad (2-5) and the second compensation mirror frame pad (2-6) are installed on the compensation mirror frame (2-2) and used for adjusting the optical axis height of the compensation lens (2-1); meanwhile, the compensation mirror frame (2-2) is installed on the linear guide pair (3) through the two pads; the first compensation mirror frame pad (2-5), the second compensation mirror frame pad (2-6), and the compensation mirror frame (2-2) are designed integrally.

6. The zero-backlash zoom compensation mirror group driving device with stable pre-tightening force according to claim 1, wherein: The linear guide pair (3) is composed of a linear guide rail (3-1) and a sliding block (3-2); the sliding block (3-2) is installed on the linear guide rail (3-1) and moves along a straight line; and the sliding block (3-2) is installed with the zoom mirror group (1) and the compensation mirror group (2) respectively.

7. The zero-backlash zoom compensation mirror group driving device with stable pre-tightening force according to claim 5, wherein: The cam shaft (4) includes a zoom cam groove (4-1) and a compensation cam groove (4-2); the two cam grooves respectively apply driving forces to the bearing one (1-3) and the bearing two (2-3), so as to push the zoom mirror group (1) and the compensation mirror group (2) to move along the linear guide pair (3).

8. The zero-backlash zoom compensation mirror group driving device with stable pre-tightening force according to claim 7, wherein: The U-shaped spring assembly (5) is composed of a compression spring (5-1), a spring guide rod (5-2), and a guide rod support (5-3); the spring guide rod (5-2) is in a U-shaped structure; the spring guide rod (5-2) passes through the compression spring (5-1), the second zoom mirror frame pad (1-6), and the second compensation mirror frame pad (2-6) and is installed on the guide rod support (5-3); the two ends of the compression spring (5-1) are respectively close to the second zoom mirror frame pad (1-6) and the second compensation mirror frame pad (2-6) and are compressed to provide a pre-tightening force, so that the bearing one (1-3) and the bearing two (2-3) are always respectively close to the same side groove surface of the zoom cam groove (4-1) and the compensation cam groove (4-2), for eliminating the mechanism backlash of the driving device.

9. The zero-backlash zoom compensation mirror group driving device with stable pre-tightening force according to claim 7, wherein: The zoom cam groove (4-1) and the compensation cam groove (4-2) in the cam shaft (4) are flattened and in a figure-of-eight shape.

10. The zero-backlash zoom compensation mirror group driving device with stable pre-tightening force according to claim 9, wherein: When the camshaft (4) is rotated and driven, the variable magnification lens group (1) and the compensation lens group (2) move in opposite directions, and the two lens groups move in a form of moving closer to each other from both ends to the middle or moving away from each other from the middle to both ends. The pre-tightening forces borne by the variable magnification lens group (1) and the compensation lens group (2) are equal in size and consistent in direction, and the torques generated when the pre-tightening forces act on the camshaft (4) are opposite, so that the camshaft (4) tends to be statically stable.

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