CN202995127U - Non-thread voice coil motor of closed loop positioning control system - Google Patents

Abstract

The utility model discloses a threadless voice coil motor of a closed-loop positioning control system, which includes a base, a guide shaft fixed on the base, a magnetic circuit assembly, and a load installation that is rigidly connected with the magnetic circuit assembly and wears the guide shaft. The slide base, the lens group mounted on the load mounting slide base, and the fixed circuit component composed of coils. The annular wall inside the load mounting slide forms an accommodation space, and the accommodation space is enough to accommodate the lens group. Under the interaction between the electromagnetic force generated by the coil group that obtains power and the magnetic force provided by the movable magnetic circuit assembly, the load mounting slide is moved linearly in the direction of the guide shaft. There are no screw threads on the annular wall of the load mounting slide and on the outer surface of the lens group, so that the lens group is in a sliding fit state after being installed on the load mounting slide.

Description

Threadless Voice Coil Motor for Closed Loop Positioning Control System

technical field

The utility model relates to a voice coil motor, in particular to a screwless voice coil motor of a closed loop positioning control system.

Background technique

In order to perform precise positioning control on the lens group, a voice coil motor (Voice Coil Motor, VCM) that can stably move the moving parts is usually used to move the lens group. The mechanism of the voice coil motor that can stably move the moving part is mainly to place the coil in the magnetic circuit containing the permanent magnet.

In the optical system, when the current passes through the coil, the magnetic field formed by the permanent magnet will generate an interactive propulsion according to Fleming's left-hand rule, so that the seat rigidly connected to the permanent magnet is moved, and at the same time it is driven and fixed on the seat The lens group achieves the purpose of optical zoom and focus.

Existing voice coil motors used in optical system autofocus all use metal shrapnel, so that the force generated by the seat when the coil is fed with a specific current is balanced with the deformation and elasticity of the metal shrapnel according to Hooke's law, so that the seat is to a specific location. Of course, the continuous maintenance of the position must continuously consume the power passed through the coil current, which is really unfavorable for the low power consumption requirement of the handheld device.

In order to overcome this problem, Taiwan Patent Publication No. I287906 "Power-saving Design of Voice Coil Motor" is mainly based on the power-saving design of the above-mentioned voice coil motor mechanism design without shrapnel. In said patent, the voice coil motor is mainly composed of a magnetic circuit assembly, a load mounting slide seat rigidly connected to the magnetic circuit assembly, a base, a plurality of guide shafts fixed on the base, and a fixed circuit assembly. Under normal circumstances, when the coils of the fixed circuit assembly receive power, the load installation slide will move linearly along the direction of the guide shaft under the interaction with the magnetic force provided by the magnetic circuit assembly. In order to achieve the purpose of saving electricity, when designing the attraction force of the load mounting slide to the guide shaft, it can still be enough to resist the load mounting slide and its The gravitational force generated by the mounted lens group.

In existing voice coil motors, regardless of shrapnel or non-shrapnel type, the thread between the load mounting slider and the lens group is prone to tolerance or installation method differences, which will cause the optical image quality of each voice coil motor to be different. difference. For example, when the first lens group was assembled, the lens group was rotated 2.8 times, and the second lens group was rotated 2.85 times. As a result, the rotated angles of the two lens groups were different after installation, resulting in differences in optical image quality.

In order to overcome the above problems, there must be a focus adjustment action after the lock is completed. By rotating the lens group slightly, the angle of rotation of each lens group after installation is the same, so as to ensure that the image is shot at infinity. position is clear. However, based on the existence of the screw thread and slightly rotating the focusing method of the lens group, the precision of the load mounting slide and the lens group must be very high.

In the process of focusing, when the mounting slide and the lens group are made of plastic, there will inevitably be a slight amount of elastic deformation, resulting in the problem of out-of-focus after focusing. If focusing on the shrapnel-type voice coil motor, the shrapnel is deformed due to the torque problem, and the entire voice coil motor is damaged.

In addition, in the process of locking the lens group on the load mounting slide, no matter the material used is plastic or metal, it is easy to force the glass fiber or the load mounting slide due to the torque between the two screws. Metallic glass, which produces particles. If the unfortunate particles fall onto the image sensor, the image will be blurred. Or, an additional dust-proof design is required to absorb the falling particles, but this will make it difficult to further reduce the cost.

In addition, the process of attaching the lens group to the load mounting slider actually consumes a lot of manpower and time when attaching the screws, which is not conducive to further reducing the assembly cost.

Utility model content

The technical problem to be solved by the utility model is: in order to make up for the deficiencies of the prior art, a screwless voice coil motor for a closed-loop positioning control system is provided, mainly because the load mounting slide seat and the lens group have no screw teeth, so that Avoid the problems caused by screw teeth in the past (higher precision requirements, installation rotation angle, damaged shrapnel, particle pollution, etc.).

The screwless voice coil motor of the closed loop positioning control system of the utility model adopts the following technical scheme:

The screwless voice coil motor includes a base; a guide shaft, fixed on the base; a magnetic circuit assembly; a load mounting slide, rigidly connected to the magnetic circuit assembly and passing through the guide shaft; a lens group, installed on the The load is mounted on the sliding seat; the fixed circuit assembly is composed of coils; wherein, the annular wall inside the load mounting slide constitutes an accommodating space, and the accommodating space is sufficient to accommodate the lens group, and when the power is obtained Under the interaction between the electromagnetic force generated by the set of coils and the magnetic force provided by the movable magnetic circuit assembly, the load installation slide moves linearly along the direction of the guide shaft, and the load installation slide Both the annular wall surface and the outer surface of the lens group have no screw teeth, so that the lens group presents a sliding fit state after being installed on the load mounting slide.

The inner diameter of the load mounting slide is 0.02 mm to 0.2 mm larger than the outer diameter of the lens group.

After the lens group is installed on the load mounting slide, glue is coated on the gap between the lens group and the load mounting slide to prevent the lens group from slipping out of the load mounting slide.

There is a glue material on the annular wall surface inside the load mounting slide or the outer surface of the lens group.

The two ends of the displaceable range when the load mounting slide moves linearly along the direction of the guide shaft are respectively defined as an initial position and a limit position. The screwless voice coil motor also includes a controller, based on a closed The position information obtained by the loop positioning control system enables the load mounting slide mounted with the lens group to obtain a clear image when shooting at a first position adjacent to the initial position and a second position adjacent to the extreme position , the first position and the second position are respectively defined as the near end and the infinity.

An annular body is provided at the upper edge of the outer surface adjacent to the light-emitting surface of the lens group, the inner diameter of the annular body is slightly wider than the outer surface, and at the annular wall away from the light-emitting surface An annular receiving surface is vertically extended, and the annular body and the annular receiving surface are structurally compatible with each other.

Indicating structures corresponding to each other are provided on the annular wall surface inside the load installation slide or on the outer surface of the lens group to indicate the installation direction of the lens group.

The indicative structure is a concave or convex structure.

The movable magnetic circuit assembly of the load mounting slide is mainly composed of a plurality of non-annular magnets, a plurality of non-annular surface yokes and bottom yokes.

At least two guide shafts are arranged symmetrically on the base.

Therefore, according to the above-mentioned technical scheme, the screwless voice coil motor of the closed-loop positioning control system of the present invention has at least the following advantages and beneficial effects: In order to avoid the problems caused by the prior art with screw teeth (installation rotation angle, Damage to shrapnel, particle pollution, etc.), the annular wall of the load mounting slide and the outer surface of the lens group have no screw teeth but a smooth surface, and the inner diameter of the load mounting slide is 0.02mm to 0.2mm larger than the outer diameter of the lens group (For example, the inner diameter of the load mounting slide can be 6.03 mm, and the outer diameter of the lens group can be 6 mm), so that the lens group is installed on the load mounting slide and presents a sliding fit state.

Description of drawings

1 to 4 are schematic diagrams of the screwless voice coil motor of the closed-loop positioning control system of the present invention.

Wherein, the reference signs are explained as follows:

1 Voice Coil Motor 41 Coil

422, 421 Guide shaft 43 Base

441, 442 Non-ring magnets 443, 444 Non-ring surface yokes

445 Bottom Yoke 45 Load Mounting Sliding Block

451 Annular wall 4511 Concave structure

4512 Annular receiving surface 452 Accommodating space

46 Lens Group 461 External Surface

4611 Convex structure 4612 Annulus

50 Controller 51 Storage Media

Detailed ways

Please refer to FIG. 1 to FIG. 4 . FIG. 1 to FIG. 4 are schematic diagrams of the threadless voice coil motor of the closed-loop positioning control system of the present invention. As shown in Figure 2, the screwless voice coil motor 1 of the utility model closed-loop positioning control system is mainly composed of a base 43, which is fixed on the base 43 to symmetrically set guide shafts 422, 42 1, a magnetic circuit assembly (for example, it can be formed by a bottom yoke) Iron 445, non-ring magnets 441, 442, non-ring surface yokes 443, 444, as shown in Figure 1), rigidly connected with the magnetic circuit assembly and the load installation sliding seat 45 that passes through the guide shaft 422, 421 , the lens group 46 installed on the load mounting slide 45 , and the fixed circuit assembly composed of the coil 41 are composed.

When the load installation slide 45 is assembled with the base 43, etc., the guide shafts 422, 421 fixed on the base 43 must contact the open arc bearing surface of the load installation slide 45 or pass through the through hole. And the air gap between the bottom yoke 445 in the magnetic circuit assembly and the non-ring magnets 441 , 442 , and the non-ring surface yokes 443 , 444 has accommodated the coil 41 . In this way, as long as the electromagnetic force generated by the electric coil 41 interacts with the magnetic force provided by the magnetic circuit assembly, the load mounting slide 45 can move linearly along the directions of the guide shafts 422, 421 to achieve optical Zoom purpose.

As shown in FIG. 3 , in order to install the lens group 46 on the load mounting slide 45 , the annular wall surface 451 inside the load mounting slide 45 constitutes an accommodating space 452 , and the accommodating space 452 is sufficient to accommodate the lens group 46 .

In order to avoid the problems (installation rotation angle, damage to shrapnel, particle pollution, etc.) brought by the threaded teeth in the prior art, the annular wall surface 451 of the load installation slide 45 and the outer surface 461 of the lens group 46 are all without threaded teeth and It is a smooth surface, and the inner diameter of the load installation slide seat 45 is greater than the outer diameter of the lens group 46 by 0.02mm to 0.2mm (for example, the inner diameter of the load installation slide seat 45 can be 6.03mm, and the outer diameter of the lens group 46 can be 6mm), so that the lens group 46 is mounted on the load installation slide 45 and presents a sliding fit state. It should be noted that the screwless design is suitable for shrapnel and non-shrapnel voice coil motors.

After the lens group 46 is installed on the load installation slide seat 45, the gap between the lens group 46 and the load installation slide seat 45 is coated with glue (such as UV glue) to prevent the lens group 46 from falling out of the load installation slide seat 45.

In addition, the annular wall surface 451 of the load installation slide 45 and the outer surface 461 of the lens group 46 are coated with colloidal materials to increase the friction between the load installation slide 45 and the lens group 46 and prevent the lens group 46 from Drop off the load mounting slide 45. However, the uniformity of coating the colloidal material and the precision of thickening must be properly controlled, otherwise the lens group 46 will easily have the problem of inclination angle.

However, since the position of the photosensitive assembly of the camera is fixed, only the lens group can be moved, so the tolerance problem of the lens group 46 after being installed on the load mounting slide 45, if not properly handled, will be lost when shooting at infinity. Cannot focus smoothly, and cannot obtain a clear image. That is to say, when the load mounting slide 45 moves linearly along the direction of the guide shafts 422, 421, if it is not processed, the load mounting slide 45 is directly placed at the two ends of the displaceable range (respectively defined as initial position and It will not be easy to obtain a clear image when shooting at the extreme position), but the screwless voice coil motor 1 of the present invention can no longer rotate the focusing mode of the lens group 46 slightly based on the existence of the screw teeth. However, in the closed-loop positioning control system adapted to the present invention (for example, Taiwan Patent Publication No. M304688 "Voice Coil Motor Positioning Device with Hall Effect Position Feedback Sensor", but not limited to the means of implementation of the patent case) In the middle, it can be overcome by using the position information provided by the closed-loop positioning control system.

Specifically, as shown in FIG. 4 , in the closed-loop positioning control system, the controller 50 will firstly make the load mounting slide 45 on which the lens group 46 is installed perform a full-stroke operation from the initial position to the limit position, and use the closed-loop The position information obtained by the loop positioning control system, in order to obtain the first position and the second position of a clear image when it is close to the initial position and the extreme position, define them as the near end and infinity respectively, and store them in storage medium 51. For example, the second position, which is slightly less than 0.01mm from the limit position of the full stroke, can obtain a clear image when taking pictures at infinity. Therefore, when the user adjusts the focus to the near end and infinity, the lens group 46 will only be moved to the first position which is slightly higher than the initial position by 0.01 mm, and the second position which is slightly lower than the limit position by 0.01 mm. In this way, it is only necessary to obtain a clear image when shooting at infinity according to the position information of the near end and infinity pre-stored in the storage medium 51 , thereby eliminating the traditional tedious focusing steps.

In addition, there are indicating structures corresponding to each other on the annular wall surface 451 inside the load installation slide 45 or the outer surface 461 of the lens group 46 to indicate the installation direction of the lens group 46 . As shown in FIGS. 3 to 4 , the indicative structure of the load mounting slide 45 is a concave structure 4511 , while the indicative structure of the lens group 46 is a convex structure 4611 . However, it should be noted that the indicative structure of the load mounting slide 45 may be a convex structure 4611 , while the indicative structure of the lens group 46 may be a concave structure 4511 . In conclusion, the indicative structures of the two are structurally compatible with each other.

In order to more clearly indicate the installation rotation angle of the lens group 46 , the convex structure 4611 may only be formed on the upper half of the outer surface 461 to indicate that the lens adjacent to the convex structure 4611 is a light-emitting surface.

Although the annular wall surface 451 of the load mounting slide 45 and the outer surface 461 of the lens group 46 have no thread, which can greatly reduce the problem of particle contamination, in order to further avoid the annular wall surface 451 of the load mounting slide 45 and the lens group 46 Colloidal material is coated on the outer surface 461 of the lens group 46, or the particle pollution after the material of the outer surface 461 of the annular wall 451 and the lens group 46 is peeled off, and an annular body 4612 is arranged on the upper edge of the outer surface 461 adjacent to the light-emitting surface (its inner diameter is slightly wider than the outer surface 461), and a ring-shaped receiving surface 4512 is vertically extended away from the ring-shaped wall 451 of the light-emitting surface. 3 to Figure 4. In this way, the particles generated between the load installation slide 45 and the lens group 46 during installation can be received by the ring-shaped receiving surface 4512 to avoid falling to the photosensitive assembly inside the camera.

Therefore, according to the above-mentioned technical scheme, the screwless voice coil motor of the closed-loop positioning control system of the present invention has at least the following advantages and beneficial effects: In order to avoid the problems caused by the prior art with screw teeth (installation rotation angle, Damage to shrapnel, particle pollution, etc.), the annular wall of the load mounting slide and the outer surface of the lens group have no screw teeth but a smooth surface, and the inner diameter of the load mounting slide is 0.02mm to 0.2mm larger than the outer diameter of the lens group (For example, the inner diameter of the load mounting slide can be 6.03 mm, and the outer diameter of the lens group can be 6 mm), so that the lens group is installed on the load mounting slide and presents a sliding fit state.

The above descriptions are only preferred embodiments of the utility model, and are not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims (10)

1. A closed loop positioning control system without the thread voice coil motor, it is characterized in that, describedly comprise without the thread voice coil motor:

   Base;

   Leading axle is fixed on described base;

   The magnetic circuit assembly;

   Slide is installed in load, and described magnetic circuit assembly and wear described leading axle is rigidly connected;

   Lens group is arranged on described load and installs on slide; And

   The permanent circuit assembly is made of coil;

   Wherein, the ring-type wall formation accommodation space of slide inside is installed in described load, described accommodation space is enough to hold described lens group, and under the magnetic force that electromagnetic force that the group coil that obtains electric power produces and movable magnetic circuit assembly provide interacts, the direction that makes described load installation slide follow described guidance axis is made traveling priority, the described ring-type wall of described load installation slide and the outer surface of described lens group make described lens group be installed in and present the sliding state of joining after slide is installed in described load all without thread.
2. Closed loop as claimed in claim 1 positioning control system without the thread voice coil motor, it is characterized in that, described load is installed the internal diameter of slide greater than the external diameter 0.02mm to 0.2mm of described lens group.
3. 3. closed loop as claimed in claim 1 positioning control system without the thread voice coil motor, it is characterized in that, after described lens group is installed in described load installation slide, gap between described lens group and described load installation slide scribbles colloid, to prevent that described lens group from skidding off described load slide is installed.
4. Closed loop as claimed in claim 1 positioning control system without the thread voice coil motor, it is characterized in that, install in described load on the described outer surface of the described ring-type wall of slide inside or described lens group and have colloidal materials.
5. 5. closed loop as claimed in claim 1 positioning control system without the thread voice coil motor, it is characterized in that, the two-end-point that direction that slide the following described guidance axis movable scope when making traveling priority is installed in described load is defined as respectively initial position and extreme position, describedly also comprises without the thread voice coil motor:

   Controller, the positional information that obtains based on the closed loop positioning control system, making the described load that described lens group is installed that slide is installed takes and when obtaining sharp image, described primary importance and the described second place are defined as respectively proximal end and infinite point in the second place of the primary importance of contiguous described initial position and contiguous described extreme position.
6. 6. closed loop as claimed in claim 1 positioning control system without the thread voice coil motor, it is characterized in that, upper limb place at the described outer surface of the exiting surface of contiguous described lens group is provided with ring bodies, the internal diameter of described ring bodies slightly is wider than described outer surface, vertically extend the ring-type continuing surface at the described ring-type wall place away from exiting surface, described ring bodies and described ring-type continuing surface have matching on structure each other.
7. 7. closed loop as claimed in claim 1 positioning control system without the thread voice coil motor, it is characterized in that, install in described load on the described outer surface of the described ring-type wall of slide inside or described lens group and be provided with the indicative structure that corresponds to each other, to indicate the installation direction of described lens group.
8. Closed loop as claimed in claim 7 positioning control system without the thread voice coil motor, it is characterized in that, described indicative structure is the concave or convex structure.
9. Closed loop as claimed in claim 1 positioning control system without the thread voice coil motor, it is characterized in that, the described movable magnetic circuit assembly that slide is installed in described load mainly is comprised of a plurality of non-ring magnets, a plurality of non-ring-like surperficial yoke and end yoke.
10. Closed loop as claimed in claim 1 positioning control system without the thread voice coil motor, it is characterized in that, plural leading axle is set on described base symmetrically at least.

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