Gap elimination zoom cam mechanism of optical lens and optical lens
By using a combination of conical roller and spring in the cam-type zoom mechanism, the imaging blur and accuracy reduction caused by the gap between the roller and the cam curve groove is solved, and higher imaging quality and optical measurement accuracy are achieved.
Patent Information
- Application Number
- CN202510003357.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-02
- Publication Date
- 2025-03-07
AI Technical Summary
In the existing cam-type zoom mechanism, there is a gap between the roller and the cam curve trough, resulting in blurring of imaging and reduced optical measurement accuracy.
The first roller and a spring with the outer peripheral surface being a conical surface are used to press the outer peripheral surface of the first roller on the curve groove of the focus cam to ensure that the first roller always contacts the curve groove during the zooming process and eliminates gaps.
Effectively eliminates the gap between the roller and the cam curve trough, improving imaging quality and optical measurement accuracy.
Smart Images
Figure CN119575587A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a lens zoom mechanism and an optical lens, belonging to the technical field of optical element adjustment devices. Background Art
[0002] In zoom optical lenses, a cam structure is usually used to achieve its zoom function. Figure 1 As shown, when zooming, the outer cam barrel 100 rotates, and its variable magnification lens group 200 and compensation lens group 300 are driven by the guide pin 400 and move linearly along their respective cam curve grooves in a regular manner, ensuring that the image plane remains unchanged while the focal length changes. The cam-type zoom mechanism is widely used in optical zoom lenses due to its simple and compact structure and easy processing and adjustment.
[0003] The guide pin 400 of the existing cam-type zoom mechanism and the cam curve groove are ground and matched to achieve a close fit. However, due to processing errors, the cam curve groove has processing errors of different widths throughout the entire process. At the same time, the optical lens may experience different temperature environments during use. Therefore, Figure 2 As shown, in order to enable the cam mechanism to run smoothly, a certain gap 600 is left between the roller 500 on the guide pin 400 and the cam curve groove.
[0004] Due to the gap between the roller 500 and the focusing cam curve groove, the cam-type zoom lens has the following disadvantages: (1) When zooming, the compensation lens group 300 cannot follow the agreed curve to run synchronously with the zoom lens group 200, causing the optical image plane of the lens to shift, the image quality to decline, and in severe cases, the image will be blurred. (2) During the focusing process of the optical lens, when the direction is changed, the center of the visual axis will be offset on the image plane, reducing the accuracy of optical measurement. Summary of the invention
[0005] In view of the above-mentioned defects of the prior art, the task of the present invention is to provide an optical lens anti-backlash zoom cam mechanism and an optical lens to solve the problems of image blur and reduced optical measurement accuracy caused by the gap between the roller and the cam curve groove.
[0006] The technical solution of the present invention is as follows: an optical lens backlash eliminating zoom cam mechanism, comprising a focusing cam and a focusing slide, the focusing cam is provided with a focusing curve groove, a guide pin is fixedly provided on the focusing slide, a first roller and a spring are passed through the guide pin, the outer peripheral surface of the first roller is a conical surface, and the spring is used to press the outer peripheral surface of the first roller against the side wall of the focusing curve groove.
[0007] Furthermore, the side wall of the focusing curved groove is a sloped surface, and the taper of the outer peripheral surface of the first roller matches the slope of the side wall of the focusing curved groove.
[0008] Furthermore, the guide pin includes a head and a shaft body, the first roller is inserted into the shaft body, and the spring is located between the head and the first roller.
[0009] Furthermore, a spring groove is provided at the first end of the first roller, and the spring is arranged between the groove bottom of the spring groove and the head.
[0010] Furthermore, the material of the first roller is molybdenum disulfide.
[0011] Furthermore, the optical lens backlash-eliminating zoom cam mechanism comprises a main lens barrel, the main lens barrel is located between the focusing cam and the focusing slide, the main lens is provided with a straight groove, and the guide pin is provided with a second roller that cooperates with the straight groove.
[0012] Furthermore, the guide pin includes a head and a shaft body, the shaft body is a stepped shaft including a large diameter section and a small diameter section, the small diameter section is located at the tail section of the shaft body, the first roller is inserted into the large diameter section, and the second roller is inserted into the small diameter section.
[0013] Furthermore, the material of the second roller is molybdenum disulfide.
[0014] Another technical solution of the present invention is: an optical lens, comprising the aforementioned optical lens backlash-eliminating zoom cam mechanism.
[0015] Furthermore, it comprises a variable magnification lens group and a compensating lens group, and both the variable magnification lens group and the compensating lens group are provided with the focusing slide.
[0016] The advantages of the present invention compared with the prior art are: The present invention utilizes a first roller with a conical outer surface and a spring to press the outer surface of the first roller against the curved groove of the focusing cam. In the forward and reverse strokes of zooming, the first roller can always be in contact with both sides of the curved groove of the focusing cam. Even if there is a processing error in the width of the curved groove of the focusing cam, the first roller can only be pressed against both sides of the curved groove of the focusing cam under the action of the spring force, so that the gap between the first roller and the curved groove of the focusing cam can be effectively eliminated, thereby improving the imaging quality and the optical measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the structure of an optical lens in the prior art.
[0018] Figure 2 It is a partial structural schematic diagram of the zoom cam mechanism in the prior art.
[0019] Figure 3 Schematic diagram of the structure of the optical lens of the embodiment.
[0020] Figure 4 It is a schematic diagram of the partial structure of the optical lens backlash elimination zoom cam mechanism of the embodiment.
[0021] Figure 5 It is a schematic structural diagram of the guide pins in the optical lens backlash eliminating zoom cam mechanism of the embodiment.
[0022] Figure 6 Schematic diagram of the structure of the first roller in the optical lens backlash eliminating zoom cam mechanism of the embodiment. DETAILED DESCRIPTION
[0023] The present invention will be further described below in conjunction with the embodiments, but are not intended to limit the present invention.
[0024] Please combine Figure 3 and Figure 4 As shown, the present embodiment involves an optical lens, comprising a main lens barrel, fixed lens groups are provided at both ends of the main lens barrel, a variable magnification lens group and a compensation lens group are provided inside the main lens barrel, and the optical lens is also provided with an optical lens anti-backlash zoom cam mechanism for adjusting the positions of the variable magnification lens group and the compensation lens group on the optical axis of the optical lens.
[0025] The optical lens backlash elimination zoom cam mechanism comprises a focusing cam 1, a first roller 2, a guide pin 3, a spring 4, a second roller 5 and a focusing slide 6. The variable magnification lens group 8 and the compensation lens group 9 are respectively mounted on their respective focusing slides 6, and the following is described by referring to the structure corresponding to a focusing slide 6.
[0026] The focusing slide 6 is installed in the inner hole of the main lens barrel 7, and is precisely matched with the inner surface of the main lens barrel 7. The focusing cam 1 is installed on the outer cylinder of the main lens barrel 7, and is precisely matched with the outer surface of the main lens barrel 7. The focusing cam 1 can rotate relative to the main lens barrel 7. A focusing curved groove 101 is processed on the focusing cam 1. The cross section of the focusing curved groove is a trapezoid with a large outer side and a small inner side. In other words, the two side walls of the focusing curved groove 101 are inclined surfaces. A straight groove 701 parallel to the optical axis of the optical lens is opened on the main lens barrel 7.
[0027] Please combine Figure 5 and Figure 6As shown, the guide pin 3 passes through the focusing curve groove 101 on the focusing cam 1 and the straight groove 701 on the main lens barrel 7 from top to bottom, and is fixedly installed on the focusing slide 6 by screw thread. The guide pin 3 includes a head 301 and a shaft body, wherein the shaft body is a stepped shaft including a large diameter section 303 and a small diameter section 302, the small diameter section 302 is located at the tail section of the shaft body, and the tail section of the shaft body is processed with threads for connecting with the focusing slide 6. The first roller 2 and the spring 4 are sleeved on the large diameter section 303 of the shaft body, and the first roller 2 is tightly matched with the outer cylindrical surface of the large diameter section 303 of the shaft body through a small hole 201. A spring groove 202 is set at the first end of the first roller 2, and the aperture of the spring groove 202 is larger than the aperture of the small hole 201, and the small hole 201 and the spring groove 202 form a stepped hole. One end of the spring 4 is set against the bottom of the spring groove 202, and the other end of the spring 4 is set against the bottom surface of the head 301 of the guide pin 3. The outer circumference of the first roller 2 is a conical surface. The first roller 2 is located in the focusing curve groove 101. The spring 4 is in a compressed state to press the outer circumference of the first roller 2 against the side wall of the focusing curve groove 101. The taper of the outer circumference of the first roller 2 matches the slope of the side wall of the focusing curve groove 101, so that the outer circumference of the first roller 2 is in close contact with the side wall of the focusing curve groove 101. The second roller 5 is sleeved on the small diameter section 302 of the shaft body of the guide pin 3. The inner cylindrical surface of the second roller 5 is tightly matched with the outer cylindrical surface of the small diameter section 302, and the outer cylindrical surface of the second roller 5 is tightly matched with the straight groove 701 on the main lens barrel 7. In order to reduce the friction between the first roller 2 and the second roller 5 and the corresponding focusing curve groove 101 and the straight groove 701, the first roller 2 and the second roller 5 are both made of molybdenum disulfide.
[0028] When zooming, the focus cam 1 rotates under the drive of the external motor. Since the second roller 5 on the guide pin 3 is limited by the straight groove 701 on the main lens barrel 7, as the focus cam 1 rotates, the first roller 2 on the guide pin 3 moves in the focus curve groove 101 of the focus cam 1 and finally forms a linear motion in a direction parallel to the optical axis. The guide pin 3 is connected to the focus slide 6 by a thread, so the focus slide 6 and the lens group mounted thereon also perform a linear motion in a direction parallel to the optical axis to achieve a zooming action. In this process, due to the elastic effect of the spring 4, the outer peripheral surface of the first roller 2 is always tightly fitted with the side wall of the focus curve groove 101. Therefore, the first roller 2 can adapt to the change in the width of the entire focus curve groove 101 caused by processing and assembly of the focus curve groove 101 through its axial movement in the guide pin 3, eliminating the gap existing in the cam zoom mechanism of the prior art, and improving the imaging accuracy and optical measurement accuracy.
Claims
1. An optical lens backlash elimination zoom cam mechanism, comprising a focusing cam and a focusing slide, wherein the focusing cam is provided with a focusing curve groove, and the focusing slide is fixed with a guide pin, characterized in that: The guide pin is provided with a first roller and a spring, the outer peripheral surface of the first roller is a conical surface, and the spring is used to press the outer peripheral surface of the first roller against the side wall of the focusing curve groove.
2. The optical lens backlash eliminating zoom cam mechanism according to claim 1, characterized in that: The side wall of the focusing curved groove is a sloped surface, and the taper of the outer peripheral surface of the first roller matches the slope of the side wall of the focusing curved groove.
3. The optical lens backlash eliminating zoom cam mechanism according to claim 1, characterized in that: The guide pin comprises a head and a shaft body, the first roller is passed through the shaft body, and the spring is located between the head and the first roller.
4. The optical lens backlash eliminating zoom cam mechanism according to claim 3, characterized in that: A spring groove is provided at the first end of the first roller, and the spring is arranged between the groove bottom of the spring groove and the head.
5. The optical lens backlash eliminating zoom cam mechanism according to claim 1, characterized in that: The material of the first roller is molybdenum disulfide.
6. The optical lens backlash-eliminating zoom cam mechanism according to claim 1, characterized in that: The optical lens backlash eliminating zoom cam mechanism comprises a main lens barrel, the main lens barrel is located between the focusing cam and the focusing slide, the main lens is provided with a straight groove, and the guide pin is provided with a second roller matched with the straight groove.
7. The optical lens backlash eliminating zoom cam mechanism according to claim 6, characterized in that: The guide pin includes a head and a shaft body, the shaft body is a stepped shaft including a large diameter section and a small diameter section, the small diameter section is located at the tail section of the shaft body, the first roller is inserted into the large diameter section, and the second roller is inserted into the small diameter section.
8. The optical lens backlash-eliminating zoom cam mechanism according to claim 6, characterized in that: The material of the second roller is molybdenum disulfide.
9. An optical lens, characterized in that: An optical lens backlash-eliminating zoom cam mechanism comprising any one of claims 1 to 8.
10. The optical lens according to claim 9, characterized in that: It comprises a variable magnification lens group and a compensating lens group, and both the variable magnification lens group and the compensating lens group are provided with the focusing slide.