CN219179675U

CN219179675U - Lens driving device

Info

Publication number: CN219179675U
Application number: CN202223130741.0U
Authority: CN
Inventors: 王建华; 孔令宏; 张晓良; 陈伟伟
Original assignee: Shanghai Xinmai Electronic Technology Co ltd
Current assignee: Shanghai Xinmai Electronic Technology Co ltd
Priority date: 2022-11-24
Filing date: 2022-11-24
Publication date: 2023-06-13
Anticipated expiration: 2032-11-24

Abstract

The utility model provides a lens driving device, which comprises a rotary carrier, a base and a piezoelectric ceramic driving component, wherein the rotary carrier is provided with a plurality of grooves; a plurality of supporting feet are arranged on the periphery of the rotary carrier at equal intervals; the middle part of the base is provided with a storage hole, and a plurality of grooves are formed around the periphery of the storage hole; the rotary carrier is arranged in the object placing hole, the supporting feet are supported in the grooves, and the number of the grooves is the same as that of the supporting feet and corresponds to that of the supporting feet one by one; the side walls of the groove and the supporting leg are inclined planes which incline in the same direction; a ball is placed in the gap between the groove and the side wall of the supporting leg; the piezoelectric ceramic driving assembly is embedded in the base, and the head end of piezoelectric ceramic in the piezoelectric ceramic driving assembly is in contact with the sliding groove of the rotary carrier. The device adopts piezoelectric ceramics to drive the rotary carrier to rotate so as to drive the lens to realize focusing, has large thrust and quick response, simplifies the internal structure, is easy to assemble, has no magnetic interference between drivers and is more stable in operation.

Description

Lens driving device

Technical Field

The present utility model relates to the field of image capturing devices, and in particular, to a lens driving device.

Background

Video cameras or cameras typically employ a lens with an adjustable focal length or auto-focus, and the adjustment is by changing the position of the lens, typically by a drive motor, for driving the lens movement. Currently, auto-focusing of a handheld camera device, particularly a camera of a mobile phone, is substantially entirely performed using a Voice Coil Motor (VCM), which is a system consisting of a coil and a magnet. The energized coil receives electromagnetic force in the magnetic field, and the winding carrier is driven to linearly move along the optical axis direction (namely the Z axis) of the lens due to the electromagnetic force, so that the winding carrier finally stays at a position point when the resultant force of the electromagnetic force generated between the annular coil and the driving magnet and the elastic force of the upper spring and the lower spring reaches a balanced state.

Although the voice coil motor has the advantages of mature technology, low cost, low noise and the like, the voice coil motor has the problems of magnetic interference, insufficient thrust, unstable structure and unstable performance along with the increase of the requirements of an imaging device on imaging. For example: the double-shot motor is developed and applied to various middle-high-end mobile phones, but has certain puzzles in the practical application process, particularly, the two double-shot motors have certain magnetic interference phenomenon between each other to influence the normal exertion of the double-shot motor effect, the voice coil motor cannot avoid the defect, and meanwhile, various improvements easily cause the complex motor structure and the improvement of the assembly process difficulty; the electric conduction and the connection assembly among all parts in the voice coil motor are realized through modes such as welding, hot riveting and dispensing, meanwhile, the coil is electrified and needs to be communicated through an upper spring and a lower spring, so that the coil is electrified, and the circuit is longer.

Disclosure of Invention

The utility model aims to provide a lens driving device with high structural integration and high stability.

In order to achieve the above object, the present utility model provides a lens driving device, which includes a rotating carrier, a base, and a piezoelectric ceramic driving component;

a plurality of supporting feet are arranged on the periphery of the rotary carrier at equal intervals;

the middle part of the base is provided with a storage hole, and a plurality of grooves are formed around the periphery of the storage hole; the rotary carriers are arranged in the storage holes, the supporting feet are supported in the grooves, and the number of the grooves is the same as that of the supporting feet and corresponds to that of the supporting feet one by one;

the side walls of the groove and the supporting leg are inclined planes which incline in the same direction; the width of the groove is larger than that of the supporting leg, and at least one ball is placed in a gap between the groove and the side wall of the supporting leg;

the piezoelectric ceramic driving assembly is embedded in the base, and the head end of piezoelectric ceramic in the piezoelectric ceramic driving assembly is propped against the sliding groove of the rotary carrier.

Further, the top of the ball corresponds to a baffle plate, the baffle plate is fixed on the surface of the base, and at least part of the baffle plate is shielded right above the ball gap to prevent the ball from sliding out of the groove.

Further, the device also comprises a limiting ring, wherein a plurality of connecting columns are arranged on the surface of the base around the circumference of the object placing hole; the limiting ring is fixed on the connecting column; and a limiting protrusion is arranged on one side of the rotary carrier, which faces the limiting ring.

Further, the piezoelectric ceramic driving component comprises piezoelectric ceramic, a first circuit board and an elastic element;

the base is internally provided with a prefabricated groove which is embedded with the piezoelectric ceramic, the first circuit board and the elastic element; after the piezoelectric ceramic is embedded in the prefabricated groove, the head end of the piezoelectric ceramic is in contact with the sliding groove of the rotary carrier; the elastic element is arranged between the tail end of the piezoelectric ceramic and the side wall of the prefabricated groove, and provides pretightening force for contact between the piezoelectric ceramic and the rotary carrier;

the first circuit board is electrically connected with the piezoelectric ceramic, and pins of the first circuit board receive current signals.

Further, the device also comprises a Hall assembly;

the Hall assembly comprises a Hall magnet, a Hall chip and a second circuit board; the Hall magnet is arranged on the side wall of the rotary carrier; the Hall chip is electrically connected with the second circuit board, the Hall chip and the Hall magnet are arranged in opposite directions, and pins of the second circuit board output Hall signals; the second circuit board is pre-buried in the base.

Further, the device also comprises a shell, wherein the shell is covered on the base and integrates the components into the device.

Further, through holes for installing lenses are coaxially formed in the middle parts of the shell, the rotary carrier and the base.

Compared with the prior art, the utility model has the advantages that:

1. the utility model adopts piezoelectric ceramics to drive the rotary carrier to rotate so as to drive the lens to realize focusing, has large thrust and quick response, and has no magnetic interference between drivers, thus the operation is more stable.

2. Compared with the traditional electromagnetic drive, the utility model has the advantages that the position adjustment of the Z-axis direction is realized by adopting the rotation of the rotary carrier, the internal structure is effectively simplified, the assembly is easy, the optical axis stability is good, the offset of the lens can not occur, and the focusing precision is higher.

3. The piezoelectric ceramic driving assembly and the Hall assembly cooperate to effectively realize closed-loop control, control the position precision of rotation adjustment of the piezoelectric ceramic driving rotary carrier and effectively improve the focusing quality of the lens.

Drawings

FIG. 1 is an exploded view of a lens driving device according to an embodiment of the present utility model;

FIG. 2 is a schematic view of a lens driving apparatus according to an embodiment of the present utility model with a housing removed;

fig. 3 is a schematic view of a lens driving apparatus according to an embodiment of the present utility model, with a housing and a base removed.

Detailed Description

In order to make the objects, technical solutions and advantages of the present utility model more apparent, the technical solutions of the present utility model will be further described below.

As shown in fig. 1, the present utility model proposes a lens driving device comprising a rotary carrier 1, a base 2 and a piezoelectric ceramic driving assembly;

a plurality of supporting feet 3 are arranged on the periphery of the rotary carrier 1 at equal intervals;

the middle part of the base 2 is provided with a storage hole 4, and a plurality of grooves 5 are arranged around the periphery of the storage hole 4; the rotary carrier 1 is arranged in the object placing hole 4, the supporting legs 3 are supported in the grooves 5, and the number of the grooves 5 is the same as that of the supporting legs 3 and corresponds to that of the supporting legs 3 one by one;

the side walls of the groove 5 and the supporting leg 3 are inclined planes which incline in the same direction; the width of the groove 5 is larger than the width of the supporting leg 3, so that a ball 6 is placed in a gap between the groove 5 and the side wall of the supporting leg 3, the assembly effect of the ball 6 is as shown in fig. 3, the side wall of the groove 5 and the side wall of the supporting leg 3 cannot be in direct contact, and the moving effect of the rotary carrier 1 is prevented from being influenced.

The piezoelectric ceramic driving assembly is embedded in the base 2, and the head end of the piezoelectric ceramic 17 in the piezoelectric ceramic driving assembly is in contact with the sliding groove of the rotary carrier 1.

The working principle of the device is as follows: according to the Z-axis displacement required by the adjustment of the lens 16, the piezoelectric ceramic driving assembly is electrified to drive the end part of the piezoelectric ceramic 17 to generate regular telescopic deformation, a friction plate in viscous connection with the piezoelectric ceramic 17 vibrates along with the piezoelectric ceramic 17, the friction plate stirs the friction plate in a corresponding sliding groove on the rotary carrier 1 to enable the rotary carrier 1 to rotate, and under the guiding action of the inclined plane and the ball 6, the rotary carrier 1 drives the lens to realize displacement in the Z-axis direction (the Z-axis direction is shown in figure 1), and finally focusing is realized.

In this embodiment, each ball top 6 corresponds to a baffle 7, and the baffle 7 is fixed on the surface of the base 2 and covers the gap of the ball 6 to prevent the ball 6 from sliding out of the gap between the groove 5 and the supporting leg 3.

In the embodiment, the device also comprises a limiting ring 8, and a plurality of connecting columns 9 are arranged on the surface of the base 2 around the circumference of the object placing hole 4; the limiting ring 8 is fixed on the connecting column 9; the side of the supporting foot 3 facing the limiting ring 8 is provided with a limiting bulge 16. The Z-axis displacement of the rotary carrier 1 is determined by the height of the connecting column 9, when the rotary carrier 1 rotates to a position close to the limiting ring 8, the limiting bulge 16 props against the surface of the limiting ring 8, so that the rotary carrier 1 and the limiting ring 8 are prevented from directly touching, the effects of preventing the rotary carrier 1 from excessive displacement and resetting after power failure are achieved, and the power consumption is reduced.

In the present embodiment, as shown in fig. 1, 2 and 3, the piezoelectric ceramic driving assembly includes a piezoelectric ceramic 17, a first circuit board 10 and an elastic member 11;

the base 2 is internally provided with a prefabricated groove embedded with piezoelectric ceramics 17, a first circuit board 10 and an elastic element 11; after the piezoelectric ceramic 17 is embedded in the prefabricated groove, the head end of the piezoelectric ceramic 17 is in contact with the sliding groove of the rotary carrier 1; the elastic element 11 is arranged between the tail end of the piezoelectric ceramic 17 and the side wall of the prefabricated groove to provide pretightening force for the contact between the piezoelectric ceramic 17 and the rotary carrier 1; the first circuit board 10 is electrically connected to the piezoelectric ceramic 17, and the pins of the first circuit board 10 receive the current signals.

As shown in fig. 1, 2 and 3, further comprises a hall assembly; the Hall assembly comprises a Hall magnet 12, a Hall chip 13 and a second circuit board 14; the Hall magnet 12 is arranged on the side wall of the rotary carrier 1; the Hall chip 13 is electrically connected with the second circuit board 14, the Hall chip 13 and the Hall magnet 12 are arranged oppositely, and pins of the second circuit board 14 output Hall signals; the second circuit board 14 is embedded in the base 2.

According to the Z-axis displacement required by lens adjustment, current with a specified size is transmitted to the piezoelectric ceramic 17 through the first circuit board 10, regular telescopic deformation is generated after the piezoelectric ceramic 17 is electrified, the rotary carrier 1 is driven to rotate and adjust through the description of the principle, in the adjustment process, when the rotary carrier 1 drives the Hall magnet 12 to move relative to the Hall chip 13, the Hall chip 13 outputs induction signals with different sizes to a control system through detecting the magnetic field change of the induction Hall magnet 12, the movement error value is judged through comprehensive calculation in the control system, and a position compensation signal is sent to a corresponding circuit of the piezoelectric ceramic 17 component to control the piezoelectric ceramic 17 to drive the rotary carrier 1 to move and adjust corresponding position precision, so that closed-loop control is realized.

In this embodiment, as shown in fig. 1, the device further comprises a housing 15, where the housing 15 covers the base 2, and integrates the components into the device. The housing 15, the rotary carrier 1 and the middle part of the base 2 are coaxially provided with through holes for mounting the lenses 16.

The foregoing is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any person skilled in the art will make any equivalent substitution or modification to the technical solution and technical content disclosed in the utility model without departing from the scope of the technical solution of the utility model, and the technical solution of the utility model is not departing from the scope of the utility model.

Claims

1. A lens driving device, which is characterized by comprising a rotary carrier, a base and a piezoelectric ceramic driving component;

2. The lens driving device according to claim 1, wherein the top parts of the balls are respectively provided with a baffle plate, and the baffle plates are fixed on the surface of the base and at least partially cover the ball gaps.

3. The lens driving device according to claim 1, further comprising a limiting ring, wherein a plurality of connecting posts are arranged on the surface of the base around the circumference of the object placing hole; the limiting ring is fixed on the connecting column; and a limiting protrusion is arranged on one side of the rotary carrier, which faces the limiting ring.

4. The lens driving apparatus according to claim 1, wherein the piezoelectric ceramic driving assembly includes a piezoelectric ceramic, a first circuit board, and an elastic member;

5. The lens driving apparatus according to claim 1, further comprising a hall assembly;

6. The lens driving apparatus of claim 1, further comprising a housing covering the base to integrate the components into the apparatus.

7. The lens driving apparatus as claimed in claim 6, wherein the housing, the rotary carrier and the base are provided with a through hole coaxially at a middle portion thereof for mounting the lens.