Sensing structure for lens moving position
Through the combination of Hall sensor and magnetic ruler, the lens displacement is monitored, and the problems of insufficient accuracy and large structural space requirements in the prior art are solved, and high-precision, low-cost, and lightweight lens displacement detection is achieved.
Patent Information
- Application Number
- CN202422154964.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-03
- Publication Date
- 2025-06-10
- Estimated Expiration
- 2034-09-03
AI Technical Summary
In the prior art, the scale marking method lacks accuracy, while the potentiometer method has high requirements for structural space, is not suitable for lightweight and miniaturized design, and is costly.
The combination of Hall sensor and magnetic ruler is used to monitor the displacement information of the lens. The Hall sensor accurately measures the displacement of the lens by detecting changes in the magnetic field, thereby achieving micron-level detection accuracy.
It realizes high-precision lens displacement detection, small size and low cost, no need to increase the lens structure size, and is suitable for lightweight and miniaturized design.
Smart Images
Figure CN222964594U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of optical elements, and particularly relates to a sensing structure for the moving position of a lens. Background Art
[0002] An optical lens can achieve optical zooming and optical focusing by moving the positions of individual lenses, thereby adjusting the imaging size and clarity of the target. The human eye or a detector can only perceive the size and clarity of an image and cannot determine the change in optical parameters. At this time, it is necessary to calculate by positioning the moving distance of the lens, so as to accurately calculate the lens performance parameters in the current state. Common position tracking adopts the form of scale marks or potentiometers. The scale marks are to add symbols such as engraved lines on the lens structural parts to indicate the focal length state, and the potentiometer form is to judge the moving distance of the lens according to the change in the resistance value of the potentiometer.
[0003] The scale mark method has general accuracy due to manual measurement, and can only identify the current position through the human eye, cannot be automatically read and displayed, and cannot accurately calculate the tracking displacement. The potentiometer form requires transmission mechanisms such as gears and cams to transmit the moving amount of the lens to the rotational amount of the potentiometer shaft. The rotation of the potentiometer shaft causes a change in the resistance value of the potentiometer, and the change in the resistance value can form a corresponding relationship with the moving distance of the lens. This form has relatively high requirements for structural space and is not suitable for lightweight and miniaturized designs, and the cost of the potentiometer is relatively high. Summary of the Utility Model
[0004] The purpose of the utility model is to solve the problems that the scale mark method lacks accuracy, the potentiometer method has relatively high requirements for structural space and is not conducive to the lightweight and miniaturized design of lens products, and to propose a sensing structure for the moving position of a lens. The displacement information of the lens is monitored by a combination of a Hall sensor and a magnetic scale. The Hall sensor has high displacement detection accuracy, which can reach the micron level, and the volumes of both the Hall sensor and the magnetic scale are very small, and the displacement of the lens can be sensed without additionally increasing the lens structure size.
[0005] In order to achieve the above purpose, the technical solution provided by the utility model is as follows:
[0006] A perception structure for the moving position of a lens, comprising a fixed component, a moving component and a sensing component. The fixed component includes a base and a fixed lens, and the fixed lens is fixedly installed inside the front part of the base. The moving component includes a lens carriage and a moving lens, and the moving lens is fixedly installed inside the lens carriage. The lens carriage is movably installed inside the rear part of the base. The sensing component includes a magnetic scale, a Hall sensor and a PCB board. The Hall sensor is fixedly installed on the PCB board. Among the magnetic scale and the PCB board, one is installed at the rear part of the base, and the other is installed on the lens carriage. The positions of the magnetic scale and the Hall sensor correspond to each other. An avoidance hole is formed on the base, and the Hall sensor is placed inside the avoidance hole.
[0007] Further, a magnetic scale installation groove is formed on the outer side of the lens carriage, and the magnetic scale is installed inside the magnetic scale installation groove. A PCB board installation groove is formed on the outer side of the rear part of the base, and an avoidance hole is formed inside the PCB board installation groove. The PCB board is installed inside the PCB board installation groove, and the avoidance hole is used to give way to the Hall sensor.
[0008] Further, a PCB board installation groove is formed on the outer side of the lens carriage, and a magnetic scale installation groove is formed on the outer side of the rear part of the base. An avoidance hole is formed inside the magnetic scale installation groove, and the avoidance hole is a long hole. The PCB board is installed inside the PCB board installation groove, and the Hall sensor is placed inside the avoidance hole. When the lens carriage moves inside the base, the Hall sensor moves inside the avoidance hole, and the magnetic scale is installed inside the magnetic scale installation groove.
[0009] Further, the base and the fixed lens are fixed through a first lens retaining ring, and the lens carriage and the moving lens are fixed through a second lens retaining ring.
[0010] Further, the moving component further includes a cam and a guide pin. The cam is sleeved outside the rear part of the base. A curve hole is formed on the cam, and the curve hole extends along the circumferential direction of the cam and presents an asymmetric dislocation distribution in the radial direction of the cam. A straight groove is formed on the rear part of the base, and one end of the guide pin is fixed to the lens carriage through a thread, and the other end passes through the straight groove and the curve hole.
[0011] Further, a cam retaining ring is sleeved outside the end of the rear part of the base, and the cam retaining ring contacts the cam for limiting the cam.
[0012] Further, equidistant NS signals are recorded on the magnetic scale.
[0013] Further, the NS signals on the magnetic scale are single-cycle magnetic signals.
[0014] Compared with the prior art, the remarkable advantages of the present utility model are as follows: By using the combination of a Hall sensor and a magnetic scale to monitor the displacement information of the lens, the Hall sensor has high displacement detection accuracy, which can reach the micron level, and both the Hall sensor and the magnetic scale are very small in size. Without the need to additionally increase the lens structure size, the lens displacement can be sensed. At the same time, compared with the traditional potentiometer-type position sensing structure, it is lighter in weight and lower in cost. Brief Description of the Drawings
[0015] Figure 1 is an exploded view of a sensing structure for the moving position of a lens of the present utility model;
[0016] Figure 2 is a sectional view of a sensing structure for the moving position of a lens of the present utility model.
[0017] Description of the reference numerals in the drawings: 1, base; 2, lens carriage; 3, PCB board; 4, Hall sensor; 5, magnetic scale; 6, fixed lens; 7, first lens retaining ring; 8, moving lens; 9, second lens retaining ring; 10, straight groove; 11, cam; 12, guide pin; 13, cam retaining ring. Detailed Description of the Embodiments
[0018] In order to make the objectives, technical solutions and advantages of the present utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.
[0019] A sensing structure for the moving position of a lens provided by the present utility model, in one embodiment, as Figures 1 to 2As shown, it includes a fixed component, a moving component, and an induction component. The fixed component includes a base 1 and a fixed lens 6. The front and rear parts of the base 1 are both hollow cylinders. The inner and outer diameters of the front part of the base 1 are both larger than those of the rear part. The fixed lens 6 is fixedly installed inside the front part of the base 1, and the base 1 and the fixed lens 6 are fixed by a first lens retaining ring 7. The moving component includes a lens carriage 2, a moving lens 8, a cam 11, and a guide pin 12. The lens carriage 2 is a hollow cylinder. The moving lens 8 is fixedly installed inside the lens carriage 2, and the lens carriage 2 and the moving lens 8 are fixed by a second lens retaining ring 9. The lens carriage 2 is nested inside the rear part of the base 1. The cam 11 is sleeved outside the rear part of the base 1. A curved hole is provided on the cam 11. The curved hole extends along the circumferential direction of the cam 11 and shows an asymmetric misaligned distribution in the radial direction of the cam 11. A straight groove 10 is axially provided on the rear part of the base 1 along the axis of the base 1. One end of the guide pin 12 is fixed to the lens carriage 2 by a thread, and the other end passes through the straight groove 10 and the curved hole. In this embodiment, there are two curved holes, two straight grooves 10, and two guide pins 12. The minimum radial distance between the two ends of the curved hole is at least equal to the maximum moving distance of the lens carriage 2. If the distance is greater than the maximum moving distance of the lens carriage 2, the maximum moving distance of the lens carriage 2 is restricted by the straight groove. By rotating the cam 11 to drive the guide pin 12 to move, the lens carriage 2 can move back and forth in the base 1. Whether the nested surface between the lens carriage 2 and the base 1 contacts and whether there are other sliding structures are set according to the actual situation. The dimensional fit clearance between the guide pin 12 and the straight groove 10 is extremely small, generally less than 0.01 mm, and the positioning accuracy is high. A cam retaining ring 13 is sleeved outside the end of the rear part of the base 1. One side of the cam retaining ring 13 contacts one side of the cam 11 for limiting the cam 11.
[0020] The induction component includes a magnetic scale 5, a Hall sensor 4, and a PCB board 3. The Hall sensor 4 is fixedly installed on the PCB board 3. A magnetic scale installation groove is provided on the outside of the lens carriage 2, and the magnetic scale 5 is installed in the magnetic scale installation groove. A PCB board installation groove is provided on the outside of the front part of the base 1, and an avoidance hole is provided in the PCB board installation groove. The PCB board 3 is installed in the PCB board installation groove, and the avoidance hole is for the Hall sensor 4. The magnetic scale 5 records equidistant NS signals, and the NS signals on the magnetic scale 5 are single-cycle magnetic signals. When the Hall sensor 4 and the magnetic scale 5 move relative to each other, the Hall sensor 4 detects the magnetic field change, and after signal processing by the PCB board 3, it is converted into position information.
[0021] The magnetic field change is unidirectional, and each position corresponds to a unique magnetic field signal. The induction component is a module that can sense the magnetic field change. The position of the Hall sensor 4 needs to be close to the magnetic scale 5. When the moving component moves, it will cause a relative displacement between the magnetic scale 5 and the Hall sensor 4, and the magnetic field around the Hall sensor 4 changes. The Hall sensor 4 converts the received magnetic field signal into a current signal for output. The PCB board 3 processes the signal to obtain the moving distance of the moving component. The specific signal processing is to pre-calibrate the magnetic field signal of each position, or calibrate the relationship between the position and the magnetic field signal, and then obtain the position according to the signal during application, and then obtain the moving distance according to the position difference, that is, the sensing is completed. The sensing in the present invention can be understood as measurement, and the measurement of the moving distance is realized based on the magnetic field detection of the Hall sensor 4. The focus of this application is on the structural design, and there is no limitation on how to obtain the moving distance based on the magnetic field change detected by the Hall sensor 4, which is realized based on conventional technologies. And the Hall sensor 4 and the magnetic scale 5 use existing products, and the design of the PCB board 3 for installing the Hall sensor 4 is a conventional peripheral arrangement to support the normal operation of the Hall sensor 4, which is obtained according to the arrangement requirements of the Hall sensor 4. Among them, in this embodiment, the PCB board 3 uses the STM32F103VET6 base board, the Hall sensor 4 uses the VCP1612 linear position sensor, and the size of the magnetic scale 5 is 10 mm in length × 2 mm in width × 1 mm in thickness.
[0022] In another embodiment, a PCB board installation groove is opened on the outside of the lens carriage 2, and a magnetic scale installation groove is opened on the outside of the front part of the base 1. An avoidance hole is opened in the magnetic scale installation groove, and the avoidance hole is a long hole. The PCB board 3 is installed in the PCB board installation groove, the Hall sensor 4 is placed in the avoidance hole, and the Hall sensor 4 can move in the avoidance hole when the lens carriage 2 and the base 1 move relative to each other. The magnetic scale 5 is installed in the magnetic scale installation groove.
[0023] The above-described embodiments merely represent one or several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the utility model patent shall be subject to the appended claims.
Claims
1. A structure for sensing the movement position of a lens, characterized in that: It includes a fixed component, a moving component and a sensing component, the fixed component includes a base and a fixed lens, the fixed lens is fixedly installed in the front part of the base, the moving component includes a lens slide and a moving lens, the moving lens is fixedly installed in the lens slide, and the lens slide is movably installed in the rear part of the base, the sensing component includes a magnetic scale, a Hall sensor and a PCB board, the Hall sensor is fixedly installed on the PCB board, one of the magnetic scale and the PCB board is installed on the rear part of the base, and the other is installed on the lens slide, the position of the magnetic scale corresponds to that of the Hall sensor, an avoidance hole is opened on the base, and the Hall sensor is placed in the avoidance hole.
2. The sensing structure for lens movement position according to claim 1, characterized in that: A magnetic scale mounting groove is formed on the outer side of the lens slide, and the magnetic scale is installed in the magnetic scale mounting groove. A PCB board mounting groove is formed on the outer side of the rear portion of the base, and an avoidance hole is formed in the PCB board mounting groove, and the PCB board is installed in the PCB board mounting groove. The avoidance hole is used to make way for the Hall sensor.
3. The sensing structure for lens movement position according to claim 1, characterized in that: A PCB board mounting groove is provided on the outer side of the lens slide, a magnetic scale mounting groove is provided on the outer side of the rear portion of the base, an avoidance hole is provided in the magnetic scale mounting groove, and the avoidance hole is a long hole. The PCB board is installed in the PCB board mounting groove, and the Hall sensor is placed in the avoidance hole. When the lens slide moves in the base, the Hall sensor moves in the avoidance hole, and the magnetic scale is installed in the magnetic scale mounting groove.
4. The sensing structure for lens movement position according to claim 1, characterized in that: The base and the fixed lens are fixed via a first lens pressing ring, and the lens slide and the moving lens are fixed via a second lens pressing ring.
5. The sensing structure for lens movement position according to claim 1, characterized in that: The motion assembly also includes a cam and a guide pin. The cam is sleeved on the rear of the base. A curved hole is formed on the cam. The curved hole extends along the circumference of the cam and is asymmetrically displaced in the radial direction of the cam. A straight groove is formed on the rear of the base along the axial direction of the base. One end of the guide pin is fixed to the lens slide by a thread, and the other end passes through the straight groove and the curved hole.
6. The structure for sensing the movement position of a lens according to claim 5, characterized in that: A cam pressing ring is sleeved on the outer side of the end of the rear part of the base, and the cam pressing ring is in contact with the cam and is used for limiting the cam.
7. The lens movement position sensing structure according to claim 1, characterized in that: The magnetic scale has equidistant NS signals recorded on it.
8. The structure for sensing the movement position of a lens according to claim 7, characterized in that: The NS signal on the magnetic scale is a single-cycle magnetic signal.