A non-backlash zoom lens and method based on flexible cable transmission

Abstract

The present invention provides a zero-return zoom lens and method based on flexible cable transmission, which relate to the technical field of optical precision instruments. The zoom lens comprises a variable power group flexible cable driving mechanism and an optical lens group. The variable power lens group and the compensation lens group jointly achieve the purpose of zooming. The focusing lens group plays a focusing compensation role under changes in temperature and air pressure. The use of a first flexible cable for transmission can eliminate the return difference of the first driving device during forward and reverse rotation, thereby improving the zoom accuracy. The first elastic element and the second elastic element also provide a certain preload force, thereby eliminating the return difference caused by the matching gap, and ensuring the stability and reliability of the lens under extreme working conditions. The lens has a compact structure and occupies a small space, which is convenient for structural reconstruction and modular design, and solves the problems of return difference, focusing accuracy and zoom stagnation in the existing zoom lens.

Description

Technical Field

[0001] The present invention relates to the technical field of optical precision instruments, and in particular to a zero-backlash zoom lens and method based on flexible cable transmission. Background Art

[0002] As the imaging system's working distance becomes longer and longer, the imaging resolution requirements become higher and higher, and the environment becomes more and more complex, higher requirements are placed on the focusing accuracy of the optical system, so there is an urgent need to find a new transmission method. In recent years, precision flexible cable transmission has received more and more attention and has become an important way to improve the performance of the new generation of high-precision, lightweight precision servo mechanisms. Precision flexible cable transmission usually uses aviation stainless steel wire rope as the force transmission medium. Based on the principle of flexible transmission, the transmission of force and motion is achieved through the static friction between the wire rope and the pulley. After proper pre-tightening, the wire rope can greatly reduce the transmission backlash, and the transmission accuracy can reach more than 10μrad. It has the characteristics of high transmission accuracy, low friction loss, no lubrication required, and almost no transmission backlash.

[0003] Currently, most commonly used zoom lenses use a rotating motor in conjunction with a gear transmission to achieve lens focusing. However, the gear transmission focusing method usually leads to the following problems: (1) Due to the gap when the gears are engaged, the cam will lag when the motor rotates in the opposite direction, resulting in a return difference, which affects the focusing accuracy; (2) In order to reduce the return difference, the traditional gear drive method will try to reduce the gear gap. However, when the lens is used in an environment with high and low temperature changes, the thermal expansion and contraction of the gears will cause the zoom process to become stuck, making the zoom function ineffective. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects in the prior art, thereby providing a zero-backlash zoom lens and method based on flexible cable transmission.

[0005] A zero-backlash zoom lens based on a flexible cable transmission, comprising: a variable-power group flexible cable driving mechanism and an optical lens group, wherein the optical lens group comprises a first fixed lens group, a variable-power group, a compensating lens group, a second fixed lens group, a focusing lens group and a third fixed lens group arranged in sequence on the same optical axis, and the variable-power group flexible cable driving mechanism comprises a first flexible cable, a first driving device and a variable-power main lens barrel;

[0006] The first fixed lens group is connected to the optical path incident end of the zoom main lens barrel, the other end of the zoom main lens barrel is connected to the focusing main lens barrel, the zoom lens group is arranged on the first sliding device, the compensation lens group is arranged on the second sliding device, the first sliding device and the second sliding device are both connected to the zoom main lens barrel, the zoom main lens barrel is provided with a zoom cam, the first flexible cable is simultaneously connected to the power output end of the first driving device and the zoom cam, the zoom cam is provided with a first curved groove and a second curved groove, the zoom main lens barrel is provided with a first straight groove and a second straight groove, the first straight groove and the second straight groove are both parallel to the optical axis of the first fixed lens group, the first curved groove, the first straight groove and the first sliding device are connected by a first connecting piece, the second curved groove, the second straight groove and the second sliding device are connected by a second connecting piece, a first elastic element is arranged on the side of the first sliding device close to the first fixed lens group, a second elastic element is arranged on the side of the second sliding device close to the focusing main lens barrel, the second fixed lens group, the focusing lens group and the third fixed lens group are all arranged on the focusing main lens barrel.

[0007] Furthermore, the zoom lens also includes a focusing group cable driving mechanism, which includes a second cable and a second driving device, the second fixed lens group is arranged at the optical path incident end of the focusing main lens barrel, the third fixed lens group is arranged at the optical path exit end of the focusing main lens barrel, the focusing lens group is arranged on a third sliding device, the third sliding device is connected to the focusing main lens barrel, a focusing cam is arranged on the focusing main lens barrel, the second cable is connected to the power output end of the second driving device and the focusing cam at the same time, a third curved groove and a fourth curved groove are provided on the focusing cam, a third straight groove and a fourth straight groove are provided on the focusing main lens barrel, the third straight groove and the fourth straight groove are both parallel to the optical axis of the first fixed lens group, the third curved groove, the third straight groove and the third sliding device are connected by a third connecting member, and the fourth curved groove, the fourth straight groove and the third sliding device are connected by a fourth connecting member.

[0008] Furthermore, a third elastic element is arranged on a side of the third sliding device close to the second fixed lens group.

[0009] Furthermore, the first sliding device is a zoom lens group slide, the second sliding device is a compensation lens group slide, and the third sliding device is a focusing lens group slide. The zoom lens group is arranged on the zoom lens group slide, the compensation lens group is arranged on the compensation lens group slide, and the focusing lens group is arranged on the focusing lens group slide. Both the zoom lens group slide and the compensation lens group slide are provided with multiple guide blades.

[0010] Further, the first elastic element is a zoom lens group spring, the second elastic element is a compensation lens group spring, the third elastic element is a focusing lens group spring, a first spring pressure ring is provided at the optical path incident end of the zoom main lens barrel, the zoom lens group spring is provided between the first spring pressure ring and the zoom lens group slide, the compensation lens group spring is provided between the compensation lens group slide and the focusing main lens barrel, a second spring pressure ring is provided at the optical path incident end of the focusing main lens barrel, and the focusing lens group spring is provided between the second spring pressure ring and the focusing lens group slide.

[0011] Furthermore, the zoom lens assembly comprises a threaded pressing ring, a lens and a lens seat, the lens is mounted on the lens seat, and the threaded pressing ring is connected to both the lens and the lens seat.

[0012] Furthermore, the first driving device is a first motor, and a first motor mounting frame corresponding to the position of the first motor is provided on the zoom main lens barrel, the first motor is installed on the first motor mounting frame, and a first motor wheel is provided at the power output end of the first motor, and the first motor wheel is connected to the first flexible rope, and the second driving device is a second motor, and a second motor mounting frame corresponding to the position of the second motor is provided on the focusing main lens barrel, the second motor is installed on the second motor mounting frame, and a second motor wheel is provided at the power output end of the second motor, and the second motor wheel is connected to the second flexible rope.

[0013] Furthermore, a first encoder is provided on one end of the first motor away from the first motor rotor, and a second encoder is provided on one end of the second motor away from the second motor rotor.

[0014] Furthermore, the zoom main lens barrel is provided with a first limit sensor in pair, the zoom cam is provided with a first detection magnet corresponding to the first limit sensor, the focusing main lens barrel is provided with a second limit sensor in pair, and the focusing cam is provided with a second detection magnet corresponding to the second limit sensor.

[0015] The present invention also includes a backlash-free zoom method based on a flexible cable transmission, which is implemented based on a backlash-free zoom lens based on a flexible cable transmission as described in any of the above items. First, the first driving device is started, and the power output end of the first driving device rotates to drive the first flexible cable and the magnification cam to rotate, and at the same time, the first connecting member moves along the first curved groove and the first straight groove, and the second connecting member moves along the second curved groove and the second straight groove. Furthermore, the first sliding device drives the magnification lens group to move along the first straight groove, and the second sliding device drives the compensation lens group to move along the second straight groove, so as to achieve the purpose of zooming.

[0016] The technical solution of the present invention has the following advantages:

[0017] 1. The present invention provides a zero-return zoom lens and method based on a flexible cable transmission, wherein a zoom lens group and a compensating lens group jointly achieve the purpose of zooming, and the focusing lens group plays a role of focusing compensation under changes in temperature and air pressure. The first flexible cable and the zoom cam are driven to rotate by a first driving device, and the first connecting member moves along a first curved groove and a first straight groove, and the second connecting member moves along a second curved groove and a second straight groove, so that the first sliding device drives the zoom lens group to move, and the second sliding device drives the compensating lens group to move, so as to achieve the purpose of zooming. Compared with the feature of gear transmission having a gap, the first flexible cable used in the present application for transmission can eliminate the return difference of the first driving device during the forward and reverse rotation processes, thereby improving the zooming. Precision. In addition, the provision of the first elastic element and the second elastic element also provides a certain preload force, further eliminating the return difference caused by the matching clearance between the first connecting member and the first curved groove and between the second connecting member and the second curved groove. Compared with the traditional gear transmission which requires precise structural matching, the use of the first flexible rope for transmission zoom avoids the jamming phenomenon that is easy to occur in the gear transmission under high and low temperature changing environments, and ensures the stability and reliability of the lens under extreme working conditions. The structure of the first flexible rope can also effectively absorb the vibration and impact generated during the transmission process, making the transmission process smoother and improving the transmission efficiency. The zoom lens provided by the present application has a compact structure and occupies a small space, which is convenient for structural reconstruction and modular design.

[0018] 2. In the technical solution provided by the present invention, the second flexible cable eliminates the return difference of the second driving device during the forward and reverse rotation processes, thereby improving the zoom accuracy; the third elastic element provides a certain preload force, thereby further eliminating the return difference between the third connecting member and the third curved groove and between the fourth connecting member and the fourth curved groove due to the existence of a fitting gap; the multiple guide blades arranged on the zoom lens group slide and the compensation lens group slide provide stable guiding support for the movement of the zoom lens group slide and the compensation lens group slide, thereby improving the accuracy and stability reliability of the zoom lens group and the compensation lens group during the zooming process; the first encoder and the second encoder can provide real-time feedback of the rotation angle information of the first motor and the second motor; the first limit sensor feedbacks the extreme position state of the zoom cam movement; and the second limit sensor feedbacks the extreme position state of the focusing cam movement. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1It is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 It is a cross-sectional view of the overall structure of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of the flexible cable driving mechanism of the zoom group of the present invention;

[0023] Figure 4 It is a schematic diagram of the structure of the first limit sensor of the present invention;

[0024] Figure 5 It is a cross-sectional view of the flexible cable driving mechanism of the zoom group of the present invention;

[0025] Figure 6 It is a schematic diagram of the variable power cam structure of the present invention;

[0026] Figure 7 This is a schematic diagram of the structure of the variable-power main lens barrel of the present invention;

[0027] Figure 8 This is a schematic diagram of the structure of the zoom lens group slide of the present invention;

[0028] Fig. 9 This is a schematic diagram of the structure of the focusing main lens barrel of the present invention;

[0029] Fig.10 It is a schematic diagram of the focusing cam structure of the present invention.

[0030] Description of reference numerals:

[0031] 1-magnification group cable drive mechanism; 101-first cable; 102-first motor; 103-first encoder; 104-first motor wheel; 105-first motor mounting frame; 106-magnification main lens barrel; 107-first limit sensor; 108-first annular groove; 2-focusing group cable drive mechanism; 201-second cable; 202-second motor; 203-second encoder; 204-second motor wheel; 205-second motor mounting frame; 206-focusing main lens barrel; 207-second limit Sensor; 208-second annular groove; 3-optical lens group; 301-first fixed lens group; 302-zoom lens group; 303-compensation lens group; 304-second fixed lens group; 305-focusing lens group; 306-third fixed lens group; 4-zoom cam; 5-guide pin; 6-focusing cam; 7-zoom lens group spring; 8-compensation lens group spring; 9-focusing lens group spring; 10-threaded pressure ring; 11-zoom lens group slide; 12-compensation lens group slide; 13-focusing lens group slide; 14-lens; 15-lens seat. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] like Figure 1 , Figure 2 , Figure 3 , Figure 5 , Figure 6 , Figure 7 and Fig. 9 A zero-backlash zoom lens based on a flexible cable transmission is shown, comprising: a variable power group flexible cable driving mechanism 1 and an optical lens group 3, wherein the optical lens group 3 comprises a first fixed lens group 301, a variable power lens group 302, a compensation lens group 303, a second fixed lens group 304, a focusing lens group 305 and a third fixed lens group 306 arranged in sequence on the same optical axis, and the variable power group flexible cable driving mechanism 1 comprises a first flexible cable 101, a first driving device and a variable power main lens barrel 106;

[0037] The first fixed lens group 301 is connected to the optical path incident end of the zoom main lens barrel 106, the other end of the zoom main lens barrel 106 is connected to the focusing main lens barrel 206, the zoom lens group 302 is arranged on the first sliding device, the compensation lens group 303 is arranged on the second sliding device, the first sliding device and the second sliding device are both connected to the zoom main lens barrel 106, the zoom main lens barrel 106 is provided with a zoom cam 4, the first flexible cable 101 is connected to the power output end of the first driving device and the zoom cam 4 at the same time, the zoom cam 4 is provided with a first curved groove and a second curved groove, and the zoom main lens barrel 106 is provided with a first curved groove. A straight groove and a second straight groove, the first straight groove and the second straight groove are both parallel to the optical axis of the first fixed lens group 301, the first curved groove, the first straight groove and the first sliding device are connected by a first connecting piece, the second curved groove, the second straight groove and the second sliding device are connected by a second connecting piece, a first elastic element is arranged on a side of the first sliding device close to the first fixed lens group 301, a second elastic element is arranged on a side of the second sliding device close to the focusing main lens barrel 206, the second fixed lens group 304, the focusing lens group 305 and the third fixed lens group 306 are all arranged on the focusing main lens barrel 206.

[0038] In the above-mentioned zero-return zoom lens based on flexible cable transmission, the zoom lens group 302 and the compensation lens group 303 jointly achieve the purpose of zooming, and the focusing lens group 305 plays a role in focusing compensation under changes in temperature and air pressure. The first flexible cable 101 and the zoom cam 4 are driven to rotate by the first driving device, and the first connecting member moves along the first curved groove and the first straight groove, and the second connecting member moves along the second curved groove and the second straight groove, so that the first sliding device drives the zoom lens group 302 to move, and the second sliding device drives the compensation lens group 303 to move, so as to achieve the purpose of zooming. Compared with the characteristic of gear transmission having a gap, the first flexible cable 101 used for transmission in the present application can eliminate the return difference of the first driving device during the forward and reverse rotation processes, thereby improving In addition, the first elastic element and the second elastic element are provided to provide a certain preload force, which further eliminates the return difference caused by the matching clearance between the first connecting member and the first curved groove and between the second connecting member and the second curved groove. Compared with the traditional gear transmission which requires precise structural matching, the first flexible rope 101 is used for transmission zoom to avoid the jamming phenomenon that is easy to occur in the gear transmission under high and low temperature changing environment, and ensures the stability and reliability of the lens under extreme working conditions. The structure of the first flexible rope 101 can also effectively absorb the vibration and impact generated during the transmission process, making the transmission process smoother and improving the transmission efficiency. The zoom lens provided by the present application has a compact structure and occupies a small space, which is convenient for structural reconstruction and modular design.

[0039] like Figure 1 , Figure 2 , Fig. 9 and Fig.10As shown, in this embodiment, the zoom lens further includes a focus group flexible cable driving mechanism 2, the focus group flexible cable driving mechanism 2 includes a second flexible cable 201 and a second driving device, a second fixed lens group 304 is arranged at the incident end of the optical path of the focus main lens barrel 206, a third fixed lens group 306 is arranged at the optical path exit end of the focus main lens barrel 206, a focus lens group 305 is arranged on a third sliding device, the third sliding device is connected to the focus main lens barrel 206, a focus cam 6 is arranged on the focus main lens barrel 206, and the second flexible cable 201 is connected to the power output end of the second driving device and the focus cam 6 at the same time. 6, the focusing cam 6 is provided with a third curved groove and a fourth curved groove, the focusing main lens barrel 206 is provided with a third linear groove and a fourth linear groove, the third linear groove and the fourth linear groove are both parallel to the optical axis of the first fixed lens group 301, the third curved groove, the third linear groove and the third sliding device are connected by a third connecting piece, and the fourth curved groove, the fourth linear groove and the third sliding device are connected by a fourth connecting piece; after the second driving device is started, the second driving device is first controlled to rotate forward, that is, the power output end of the second driving device rotates clockwise, driving the second flexible cable 201 and the focusing cam 6 rotate clockwise at the same time, the third connecting member moves along the third curved groove and the third linear groove toward the direction close to the second fixed mirror group 304, and the fourth connecting member moves along the fourth curved groove and the fourth linear groove toward the direction close to the second fixed mirror group 304, thereby driving the third sliding device and the focusing mirror group 305 to move toward the direction close to the second fixed mirror group 304. Secondly, the second driving device can also be controlled to rotate in the opposite direction, that is, the power output end of the second driving device rotates counterclockwise, driving the second flexible cable 201 and the focusing cam 6 to rotate counterclockwise at the same time. The third connecting member moves along the third curved groove and the third straight groove in a direction away from the second fixed mirror group 304, and the fourth connecting member moves along the fourth curved groove and the fourth straight groove in a direction away from the second fixed mirror group 304, thereby driving the third sliding device and the focusing lens group 305 to move in a direction away from the second fixed mirror group 304. By controlling the movement of the focusing lens group 305, focusing compensation under changes in temperature and air pressure is achieved. The second flexible cable 201 eliminates the return difference of the second driving device during the forward rotation and reverse rotation, thereby improving the accuracy of focusing compensation.

[0040] like Figure 2 As shown, in this embodiment, a third elastic element is provided on one side of the third sliding device close to the second fixed lens group 304; the third elastic element provides a certain preload force, further eliminating the return difference between the third connecting member and the third curved groove and between the fourth connecting member and the fourth curved groove due to the matching clearance, thereby improving the accuracy of focusing compensation.

[0041] like Figure 1 , Figure 2 , Figure 3 , Figure 5 , Figure 7 and Figure 8 As shown, in this embodiment, the first sliding device is a zoom lens group slide 11, the second sliding device is a compensating lens group slide 12, the third sliding device is a focusing lens group slide 13, the zoom lens group 302 is arranged on the zoom lens group slide 11, the compensating lens group 303 is arranged on the compensating lens group slide 12, and the focusing lens group 305 is arranged on the focusing lens group slide 13, and the zoom lens group slide 11 and the compensating lens group slide 12 are both provided with a plurality of guide blades; the guide blades are the moving guides of the zoom lens group slide 11 and the compensating lens group slide 12. The first connecting member, the second connecting member, the third connecting member and the fourth connecting member are all guide pins 5. The zoom lens group slide 11 and the compensation lens group slide 12 are matched with the zoom main lens barrel 106 by using a hole-shaft fit. The zoom lens group slide 11, the compensation lens group slide 12 and the focusing lens group slide 13 are all provided with threaded holes corresponding to the guide pins 5. The guide pins 5 on the zoom lens group slide 11 are provided with a plurality of guide pins 5. , that is, the first connecting member, is connected with the threaded hole on the zoom lens group slide 11, and the guide pin 5 on the zoom lens group slide 11 slides in the first curved groove and the first linear groove. The guide pin 5 on the compensation lens group slide 12, that is, the second connecting member, slides in the second curved groove and the second linear groove. There are two threaded holes on the focusing lens group slide 13. The guide pin 5 on the focusing lens group slide 13, that is, the third connecting member and the fourth connecting member, are respectively connected with the two threaded holes on the focusing lens group slide 13, and the third connecting member The fourth connecting piece slides in the third curved groove and the third straight groove, and the fourth connecting piece slides in the fourth curved groove and the fourth straight groove. The movement and adjustment of the zoom lens group 302, the compensation lens group 303 and the focusing lens group 305 are realized through the connection of the guide pin 5. In the present embodiment, three guide blades are arranged on the zoom lens group slide 11 and the compensation lens group slide 12, and the guide blades on the zoom lens group slide 11 and the compensation lens group slide 12 are arranged in sequence in an alternating manner, but the specific number of the guide blades can be adjusted according to actual needs.

[0042] like Figure 1 , Figure 2 , Figure 3 , Figure 5 , Figure 7 , Figure 8 and Fig. 9As shown, in the present embodiment, the first elastic element is a zoom lens group spring 7, the second elastic element is a compensation lens group spring 8, the third elastic element is a focusing lens group spring 9, a first spring pressure ring is arranged at the optical path incident end of the zoom main lens barrel 106, the zoom lens group spring 7 is arranged between the first spring pressure ring and the zoom lens group slide 11, the compensation lens group spring 8 is arranged between the compensation lens group slide 12 and the focusing main lens barrel 206, a second spring pressure ring is arranged at the optical path incident end of the focusing main lens barrel 206, and the focusing lens group spring 9 is arranged between the second spring pressure ring and the focusing lens group slide 13; by building in the zoom lens group spring 7, the compensation lens group spring 8 and the focusing lens group spring 9 structure in the lens structure, a certain preload force is provided, the return difference caused by the existence of the fitting gap is further eliminated, and the zoom accuracy of the lens is improved.

[0043] like Figure 2 and Figure 5 As shown, in the present embodiment, the zoom lens group 302 comprises a threaded pressing ring 10, a lens 14 and a lens holder 15, wherein the lens 14 is mounted on the lens holder 15, and the threaded pressing ring 10 is connected to the lens 14 and the lens holder 15 at the same time; wherein a mounting groove corresponding to the lens 14 is reserved on the lens holder 15, and the lens holder 15 is a semi-open structure, after the lens 14 is mounted to the mounting groove, the threaded pressing ring 10 is mounted to the semi-open position of the lens holder 15, and the lens 14 is fixed to the lens holder 15, similarly, the compensation lens group 303 and the focusing lens group 305 are both installed in the above-mentioned installation method, and since the structure and installation method are the same as those of the zoom lens group 302, they are not described again here, and the first fixed lens group 301, the second fixed lens group 304 and the third fixed lens group 306 are all fixedly installed, and their positions are fixed and they do not rotate during the zooming process.

[0044] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Fig. 9 and Fig.10As shown, in this embodiment, the first driving device is a first motor 102, a first motor mounting bracket 105 corresponding to the position of the first motor 102 is provided on the zoom main lens barrel 106, the first motor 102 is installed on the first motor mounting bracket 105, a first motor rotating wheel 104 is provided at the power output end of the first motor 102, the first motor rotating wheel 104 is connected to the first flexible cable 101, the second driving device is a second motor 202, a second motor mounting bracket 205 corresponding to the position of the second motor 202 is provided on the focus main lens barrel 206, and the second motor 202 is installed on the first motor mounting bracket 105. On the second motor mounting frame 205, a second motor wheel 204 is provided at the power output end of the second motor 202, and the second motor wheel 204 is connected to the second flexible cable 201; the first motor 102 is driven to drive the first motor wheel 104 to rotate, and then the first flexible cable 101 and the zoom cam 4 are driven to rotate to realize the movement of the zoom lens group 302 and the compensation lens group 303; the second motor 202 is driven to drive the second motor wheel 204 to rotate, and then the second flexible cable 201 and the focusing cam 6 are driven to rotate to realize the movement of the focusing lens group 305, thereby achieving the purpose of zooming.

[0045] like Figure 1~Figure 4 As shown, in this embodiment, a first encoder 103 is provided on one end of the first motor 102 away from the first motor wheel 104, and a second encoder 203 is provided on one end of the second motor 202 away from the second motor wheel 204; the first encoder 103 can feedback the rotation angle information of the first motor 102, so as to facilitate the control of the rotation angle of the first motor 102 during use, and the second encoder 203 can feedback the rotation angle information of the second motor 202, so as to facilitate the control of the rotation angle of the second motor 202 during use.

[0046] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Fig. 9 and Fig.10As shown, in the present embodiment, a first limit sensor 107 is arranged in pairs on the zoom main lens barrel 106, and the first limit sensor 107 is installed on the zoom main lens barrel 106 by screws, and a first detection magnet corresponding to the first limit sensor 107 is arranged on the zoom cam 4, and a second limit sensor 207 is arranged in pairs on the focus main lens barrel 206, and the second limit sensor 207 is installed on the focus main lens barrel 206 by screws, and a second detection magnet corresponding to the second limit sensor 207 is arranged on the focus cam 6; according to the detection of the first detection magnet by the first limit sensor 107, the limit position state of the movement of the zoom cam 4 can be fed back, and according to the detection of the second limit sensor The detection of the second detection magnet by the sensor 207 can provide feedback on the extreme position state of the movement of the focusing cam 6; in addition, a first annular groove 108 corresponding to the first flexible rope 101 is provided on the zoom cam 4 and the first motor wheel 104, and the first flexible rope 101 is installed in the first annular groove 108, and a second annular groove 208 corresponding to the second flexible rope 201 is provided on the focusing cam 6 and the second motor wheel 204, and the second flexible rope 201 is installed in the second annular groove 208. The setting of the first annular groove 108 improves the stability of the first flexible rope 101 during operation, and the setting of the second annular groove 208 improves the stability of the second flexible rope 201 during operation.

[0047] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 8 and Fig.10 As shown, the present invention also includes a zero-backlash zoom method based on flexible cable transmission, which is implemented based on any one of the above-mentioned zero-backlash zoom lenses based on flexible cable transmission. First, the first driving device is started, and the power output end of the first driving device rotates to drive the first flexible cable 101 and the zoom cam 4 to rotate, and at the same time, the first connecting member moves along the first curved groove and the first straight groove, and the second connecting member moves along the second curved groove and the second straight groove. Then, the first sliding device drives the zoom lens group 302 to move along the first straight groove, and the second sliding device drives the compensation lens group 303 to move along the second straight groove, so as to achieve the purpose of zooming; specifically:

[0048] First, the first motor 102 is started and controlled to rotate forward, that is, the first motor wheel 104 rotates clockwise, driving the first flexible cable 101 and the zoom cam 4 to rotate clockwise at the same time, and the first connecting member moves along the first curved groove and the first linear groove toward the direction close to the second fixed lens group 304, thereby driving the zoom lens group slide 11 and the zoom lens group 302 to move along the first linear groove toward the direction close to the second fixed lens group 304, and the second connecting member moves along the second curved groove and the second linear groove toward the direction close to the second fixed lens group 304, thereby driving the compensation lens group slide 12 and the compensation lens group 303 to move along the second linear groove toward the direction close to the second fixed lens group 304; the first motor 102 is controlled to rotate in the reverse direction. The first motor wheel 104 rotates counterclockwise, that is, the first flexible cable 101 and the zoom cam 4 rotate counterclockwise at the same time, and the first connecting member moves along the first curved groove and the first linear groove in the direction away from the second fixed lens group 304, thereby driving the zoom lens group slide 11 and the zoom lens group 302 to move along the first linear groove in the direction away from the second fixed lens group 304, and the second connecting member moves along the second curved groove and the second linear groove in the direction away from the second fixed lens group 304, thereby driving the compensation lens group slide 12 and the compensation lens group 303 to move along the second linear groove in the direction away from the second fixed lens group 304; the movement of the zoom lens group 302 and the compensation lens group 303 along the optical axis direction realizes the zoom function of the lens;

[0049] In addition, the second motor 202 is controlled to rotate in the forward direction, that is, the second motor wheel 204 rotates clockwise, driving the second flexible cable 201 and the focusing cam 6 to rotate clockwise at the same time, the third connecting member moves along the third curved groove and the third linear groove toward the direction close to the second fixed lens group 304, and the fourth connecting member moves along the fourth curved groove and the fourth linear groove toward the direction close to the second fixed lens group 304, thereby driving the focusing lens group slide 13 and the focusing lens group 305 to move along the third linear groove and the fourth linear groove toward the direction close to the second fixed lens group 304;

[0050] Secondly, the second motor 202 is controlled to rotate in the opposite direction, that is, the second motor wheel 204 rotates counterclockwise, driving the second flexible cable 201 and the focusing cam 6 to rotate counterclockwise at the same time, the third connecting member moves along the third curved groove and the third straight groove in the direction away from the second fixed lens group 304, and the fourth connecting member moves along the fourth curved groove and the fourth straight groove in the direction away from the second fixed lens group 304, thereby driving the focusing lens group slide 13 and the focusing lens group 305 to move along the third straight groove and the fourth straight groove in the direction away from the second fixed lens group 304, and the focusing compensation function under temperature and air pressure changes is realized by controlling the movement of the focusing lens group 305 along the optical axis.

[0051] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A zero-return zoom lens based on a flexible cable transmission, comprising: A variable power group cable drive mechanism (1) and an optical lens group (3), characterized in that the optical lens group (3) comprises a first fixed lens group (301), a variable power lens group (302), a compensation lens group (303), a second fixed lens group (304), a focusing lens group (305) and a third fixed lens group (306) arranged in sequence on the same optical axis, and the variable power group cable drive mechanism (1) comprises a first cable (101), a first drive device and a variable power main lens barrel (106); The first fixed lens group (301) is connected to the optical path incident end of the zoom main lens barrel (106); the other end of the zoom main lens barrel (106) is connected to the focusing main lens barrel (206); the zoom lens group (302) is arranged on a first sliding device; the compensation lens group (303) is arranged on a second sliding device; the first sliding device and the second sliding device are both connected to the zoom main lens barrel (106); a zoom cam (4) is arranged on the zoom main lens barrel (106); the first flexible cable (101) is simultaneously connected to the power output end of the first driving device and the zoom cam (4); the zoom cam (4) is provided with a first curved groove and a second curved groove; the zoom main lens barrel (106) ) is provided with a first straight groove and a second straight groove, the first straight groove and the second straight groove are both parallel to the optical axis of the first fixed lens group (301), the first curved groove, the first straight groove and the first sliding device are connected by a first connecting piece, the second curved groove, the second straight groove and the second sliding device are connected by a second connecting piece, a first elastic element is provided on a side of the first sliding device close to the first fixed lens group (301), a second elastic element is provided on a side of the second sliding device close to the focusing main lens barrel (206), and the second fixed lens group (304), the focusing lens group (305) and the third fixed lens group (306) are all provided on the focusing main lens barrel (206).

2. The zero-backlash zoom lens based on flexible cable transmission according to claim 1, characterized in that: The zoom lens further comprises a focus group flexible cable driving mechanism (2), the focus group flexible cable driving mechanism (2) comprising a second flexible cable (201) and a second driving device, a second fixed lens group (304) arranged at the light path incident end of the focus main lens barrel (206), a third fixed lens group (306) arranged at the light path emission end of the focus main lens barrel (206), a focus lens group (305) arranged on a third sliding device, the third sliding device being connected to the focus main lens barrel (206), and a focus cam (606) being arranged on the focus main lens barrel (206). ), the second flexible rope (201) is simultaneously connected to the power output end of the second driving device and the focusing cam (6), the focusing cam (6) is provided with a third curved groove and a fourth curved groove, the focusing main lens barrel (206) is provided with a third straight groove and a fourth straight groove, the third straight groove and the fourth straight groove are both parallel to the optical axis of the first fixed lens group (301), the third curved groove, the third straight groove and the third sliding device are connected by a third connecting member, and the fourth curved groove, the fourth straight groove and the third sliding device are connected by a fourth connecting member.

3. The zero-backlash zoom lens based on flexible cable transmission according to claim 2, characterized in that: A third elastic element is arranged on a side of the third sliding device close to the second fixed mirror group (304).

4. The zero-backlash zoom lens based on flexible cable transmission according to claim 2, characterized in that: The first sliding device is a variable magnification lens group slide (11), the second sliding device is a compensating lens group slide (12), and the third sliding device is a focusing lens group slide (13); the variable magnification lens group (302) is arranged on the variable magnification lens group slide (11), the compensating lens group (303) is arranged on the compensating lens group slide (12), and the focusing lens group (305) is arranged on the focusing lens group slide (13); and a plurality of guide blades are arranged on both the variable magnification lens group slide (11) and the compensating lens group slide (12).

5. The zero-backlash zoom lens based on flexible cable transmission according to claim 3, characterized in that: The first elastic element is a variable magnification lens group spring (7), the second elastic element is a compensation lens group spring (8), the third elastic element is a focusing lens group spring (9), a first spring pressure ring is provided at the optical path incident end of the variable magnification main lens barrel (106), the variable magnification lens group spring (7) is provided between the first spring pressure ring and the variable magnification lens group slide (11), the compensation lens group spring (8) is provided between the compensation lens group slide (12) and the focusing main lens barrel (206), a second spring pressure ring is provided at the optical path incident end of the focusing main lens barrel (206), and the focusing lens group spring (9) is provided between the second spring pressure ring and the focusing lens group slide (13).

6. The zero-backlash zoom lens based on flexible cable transmission according to claim 1, characterized in that: The variable power lens assembly (302) comprises a threaded pressing ring (10), a lens (14) and a lens seat (15); the lens (14) is mounted on the lens seat (15), and the threaded pressing ring (10) is connected to both the lens (14) and the lens seat (15).

7. The zero-backlash zoom lens based on flexible cable transmission according to claim 2, characterized in that: The first driving device is a first motor (102); a first motor mounting frame (105) corresponding to the position of the first motor (102) is arranged on the zoom main lens barrel (106); the first motor (102) is mounted on the first motor mounting frame (105); a first motor rotating wheel (104) is arranged at the power output end of the first motor (102); the first motor rotating wheel (104) is connected to the first flexible cable (101); the second driving device is a second motor (202); a second motor mounting frame (205) corresponding to the position of the second motor (202) is arranged on the focus main lens barrel (206); the second motor (202) is mounted on the second motor mounting frame (205); a second motor rotating wheel (204) is arranged at the power output end of the second motor (202); the second motor rotating wheel (204) is connected to the second flexible cable (201).

8. The zero-backlash zoom lens based on flexible cable transmission according to claim 7, characterized in that: A first encoder (103) is provided at one end of the first motor (102) away from the first motor rotating wheel (104), and a second encoder (203) is provided at one end of the second motor (202) away from the second motor rotating wheel (204).

9. The zero-backlash zoom lens based on flexible cable transmission according to claim 1, characterized in that: The zoom main lens barrel (106) is provided with a first limit sensor (107) in pair, the zoom cam (4) is provided with a first detection magnet corresponding to the first limit sensor (107), the focus main lens barrel (206) is provided with a second limit sensor (207) in pair, and the focus cam (6) is provided with a second detection magnet corresponding to the second limit sensor (207).

10. A method for zero-backlash zooming based on flexible cable transmission, the method being implemented based on a zero-backlash zoom lens based on flexible cable transmission as claimed in any one of claims 1 to 9, characterized in that: First, the first driving device is started, and the power output end of the first driving device rotates to drive the first flexible cable (101) and the zoom cam (4) to rotate, and at the same time, the first connecting member moves along the first curved groove and the first straight groove, and the second connecting member moves along the second curved groove and the second straight groove. Then, the first sliding device drives the zoom lens group (302) to move along the first straight groove, and the second sliding device drives the compensation lens group (303) to move along the second straight groove, thereby achieving the purpose of zooming.

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