WO2014092212A1 - Actuator for camera module - Google Patents

Abstract

The present invention relates to an actuator for a camera module and, more specifically, to an actuator for a camera module which moves one or more movers on which lenses are stacked to be displaced along an optical axis and fixes the positions of the displaced movers so as to implement an auto focus for adjusting a focal length between the lenses and an image sensor according to the position of a subject, or an optical zoom function for adjusting a zoom ratio by adjusting the distance between the lenses.

Description

Actuator for Camera Module

The present invention relates to an actuator for a camera module, and more particularly, one or more movers equipped with a lens are displaced along an optical axis, and the displaced movers are fixed to position the focal point between the lens and the image sensor according to the position of the subject. The present invention relates to an actuator for a camera module that implements an auto focus (AF) function for adjusting a distance, or an optical zoom function for adjusting a zoom magnification by adjusting a distance between a lens and a lens.

Applied to optical devices (including digital cameras, optical security monitors, mobile phones, smartphones, notepads, etc.), the incident light of the subject is converted into image data such as video recording, photography, and image recognition, or the converted image data A camera module that performs an operation including converting into image image data standardized for reproduction in a device includes a lens, an actuator, and an image sensor unit.

The lens converts the incident light of the subject into focus light, and the actuator maintains the shifter and position of the mover equipped with the lens according to the control signal of the controller so that the optimal focus light according to the distance of the subject reaches the image sensor. Do this.

The image sensor unit converts the optimal focusing light passing through the lens into image data, or converts the image data into standardized image image data, and transmits the image data or standardized image image data to the main processor. do.

On the other hand, as the camera module is applied to an optical device in recent years, a high level of volume, performance, and quality of components constituting the camera module and low price are required.

Therefore, miniaturization in the art; With low prices; There is an urgent need to develop actuators for camera modules with differentiated performance and quality, such as tilt prevention, foreign material prevention, durability enhancement, high speed and high precision displacement of the lens, and low power consumption.

An object of the present invention devised by the above-described requirements, the support structure is formed on both ends of the bracket, which is a metal piece of magnetic material, which is insert-molded in the stator, and the support structure formed on the mover facing the same, the lens mounting structure to remove the lens barrel, and the actuator portion Each configuration and structure, such as the reduction of additional labor costs due to the reduction of manufacturing man-hours, the tilting of the displacement-shifted mover, ensuring improved durability, and moving the actuator unit equipped with a lens according to the control signal of the controller The present invention provides an actuator for a camera module that provides precision for the change of the displacement of the mover and reduces the current consumption by providing a moving force for displacement movement of the child and a stopping force for maintaining the position of the displacement-moved mover.

The above object is achieved by the following configuration provided in the present invention.

Actuator for a camera module according to the present invention,

A stator having a mover accommodation space formed therein; At least one mover accommodated in the stator and mounted with a lens; And an actuator part disposed between the stator and the mover to provide a moving force for displacement movement of the mover and a stopping force for maintaining the position of the displaced mover.

The actuator unit may include a coil magnetic part including a coil for generating an electromagnetic field according to a current supply, and a magnetic material for applying a permanent magnetic field and a magnetic force of the permanent magnet; It consists of a permanent magnet formed so as to partition the N-polar part and the S-polar part, the permanent magnet and the coil magnetic part constituting the actuator portion is alternatively disposed on the inner wall of the stator and the outer wall of the mover and configured to face each other,

The moving force for displacement movement of the mover is configured to correspond to the electromagnetic force acting between the electromagnetic field generated by the current supply in the coil of the coil magnetic part and the permanent magnetic field of the permanent magnet, and the stopping force for maintaining the position of the displaced mover is the coil By blocking the current in the coil of the magnetic part is configured to comply with the magnetic force acting between the permanent magnetic field of the permanent magnet and the magnetic material of the coil magnetic part,

A fixed shaft portion made of metal is formed at both ends of the inner wall of the stator in which the permanent magnet or the coil magnetic part is disposed, and a movable shaft portion is formed on the outer wall of the mover facing the permanent magnet, and the mover accommodated in the stator accommodation space has a fixed shaft portion at the stator. Is configured to be supported in contact with the moving shaft,

The supporting force between the fixed shaft portion and the moving shaft portion is characterized in that it is configured to correspond to a magnetic force applied between the permanent magnetic field of the permanent magnet and the magnetic body of the coil magnetic portion.

Preferably, the permanent magnet of the actuator portion is disposed on the inner wall of the stator, the coil magnetic portion consisting of a coil and a magnetic body is disposed on the outer wall of the mover facing the stator, or the permanent magnet of the actuator portion is disposed on the outer wall of the mover, facing A coil magnetic part consisting of a coil and a magnetic part is disposed on an inner wall of the stator.

More preferably, the stator is formed by inserting brackets bent at both ends of a metal piece of magnetic material through insert injection, and both ends of the bent bracket form a fixed shaft portion, and the permanent magnet of the actuator portion on the inner wall surface of the bracket, or One of the components of the coil magnetic part is disposed, while the outer wall of the mover facing the movable shaft is formed in contact with the fixed shaft part, and the outer wall of the mover has a permanent magnet of the actuator part or the rest of the coil magnetic part. The component is placed.

An operation unit which is an external input means for requesting a displacement change; A memory unit in which a program or data is stored; A control unit controlling a displacement change operation corresponding to the request command in accordance with a program of the memory unit or a displacement change request command through the operation unit; A driving circuit unit which changes the direction of supply of current to the coil and supplies current to the coil (ON) or cuts off (OFF) according to a control signal of the controller; A circuit board which mounts and secures the circuit and provides an electrical connection state between the circuit including a coil, and constitutes a control circuit,

The control unit of the control circuit outputs a control signal for supplying or blocking the current and the direction designation of the current supplied to the coil of the magnetic coil of the coil according to the request command of the program or the operation unit,

The driving circuit part supplies or cuts a current in a direction specified by the coil of the magnetic part of the coil, and the actuator part has a moving force for displacing the fixed mover in the direction specified by the controller and a stopping force for maintaining the position of the displaced mover. Offering,

The control unit performs a displacement movement operation and a position maintenance operation of the mover with a stepped displacement movement characteristic of moving or moving the mover along the optical axis along the designated direction, thereby adjusting the focal length between the lens mounted on the mover and the image sensor unit. Configure to control.

As described above, in the present invention, the shaft portion (moving shaft portion and the fixed shaft portion) is parallel to the optical axis between the stator and the mover, and is supported by line or surface contact (or a plurality of point contacts). As the bearing force acts during the movement and position maintenance, it is in close contact with the moving shaft of the stator of the stator, which is parallel to the optical axis. Therefore, the tilting of the lens mounted on the mover is suppressed and the focus light transmitted through the lens is imaged. The sensor unit reaches without changing the depth of focus.

In addition, by forming the fixed shaft portion of the bent ends of the bracket made of a metal piece (abrasion resistance strong) of the magnetic material placed on the stator, the occurrence of foreign matters due to the wear of the fixed shaft portion and the change of characteristics due to wear is minimized.

In addition, the bracket is made of a metal plate made of magnetic material to shield the external magnetic field flowing from the outside, and the permanent magnetic field emitted from the permanent magnet is directed toward the coil magnetic part without leaking to the outside. Displacement movement and position maintenance of the moved mover are implemented stably.

In particular, since the lens is accommodated in the mover in which the lens receiving space is formed, it is possible to reduce the manufacturing cost and volume by preventing the foreign matter and reducing the manufacturing man-hour.

In addition, the present invention is to perform the displacement movement and position maintenance step by step in accordance with the stepped displacement characteristics that step the process of supplying the current in the specified direction to the coil of the magnetic part of the coil through the control circuit, and interrupting It is composed.

Therefore, in the present invention, since there is no current consumption in the process of blocking the current, the driving current can be minimized and the mover equipped with the lens according to the speed of the control signal of the controller can secure the focal length at high speed, and The focal length can be precisely adjusted by adjusting the time width of the supplied current.

1 to 7 illustrate a first embodiment of the present invention configured to accommodate a single mover mounted with a lens in the stator, and to arrange and fix an actuator portion between the stator and the mover to perform an auto focus (AF) function. It shows the configuration of the actuator for the camera module according to the embodiment and the embodiment of the working state,

8 to 13 accommodate a pair of movers mounted with a lens in the stator and arrange and fix the actuator portion between each mover and the stator to provide optical zoom function through individual displacement movement and position maintenance of each mover. The configuration of the actuator for a camera module according to the second embodiment of the present invention, configured to perform, and an example of an operating state are shown.

14 shows a control circuit for controlling the actuator portion of the actuator for a camera module according to the present invention,

Figure 15 shows the movement distance characteristics of the mover of the actuator for the camera module according to the present invention.

1. Actuator for Camera Module

10. Stator 11. Moving Space

12. Space for image sensor unit 13. Bulkhead

13a. Focus hole 14. Cover

14a. Job 15. Bracket

15a. Fixed shaft part 16. Rushing protrusion

20. Mover 21. Lens receiving space

21a. Thread

22. Lens barrel 22a. Thread

22b. Lens receptacle 22c. Lens holder

23. Moving shaft part 24. Coil adhesion protrusion

100. Actuator for Camera Module

110. Stator 110A, 110B. Split body

110c, affix 110d. Home

111. Receiving space for mover 112. Receiving space for image sensor

113. Bulkhead 113a. Focus ball

114. Bulkhead 114a. Entrance

115. Bracket 115a. Fixed shaft part

120. The mover 121. Lens receiving space

122. Lens holder 123. Moving shaft part

124. Permanent magnet receiver

Actuator section 210. Permanent magnet

211.N polarity 212.S polarity

213. Stimulus separation line

220. Coil magnetic part 221. Coil

222. Magnetism

310. Control unit 311. Control panel

312. Control panel 320. Drive circuit

321. Bridge circuit 322. Constant voltage source

330. Circuit Board

400. Image sensor unit 410. Image sensor

420. Circuit Board

L. Lens F. IR Filter

Hereinafter, an actuator for a camera module proposed as a preferred embodiment of the present invention with reference to the accompanying drawings will be described in detail.

1 to 7 illustrate a first embodiment of the present invention configured to accommodate a single mover mounted with a lens in the stator, and to arrange and fix an actuator portion between the stator and the mover to perform an auto focus (AF) function. The configuration of the actuator for the camera module according to the present invention and an embodiment of an operating state are illustrated, and FIGS. 8 to 13 accommodate a pair of movers mounted with a lens in the stator, and arrange the actuator portion between each mover and the stator, respectively. The configuration of the actuator for the camera module according to the second embodiment of the present invention configured to perform the optical zoom function through the individual displacement movement and the position maintenance of each mover, and an example of the working state are shown. .

Actuator (1, 100) for the camera module according to the present invention, as shown in Figures 1 to 13 and the stator (10, 110) is formed with a moving receiving space (11, 111); A mover (20, 120) accommodated in the mover accommodation space (11, 111) of the stator (10, 110) and mounted with a lens (L); A displacement force between the stators 10 and 110 and the movers 20 and 120 and the movers 20 and 120 mounted with the lens L, and the displacements of the movers 20 and 120. An actuator unit 200 provides a stopping force for maintaining position.

In the first embodiment of the present invention, as shown in Figures 1 and 2, the stator (10, 110) is made of an injection molding, the movable range (Stroke Range) for displacement movement of the mover (20, 120) A mover accommodation space (11, 111) for receiving a mover including an air gap; The image sensor unit accommodating spaces 12 and 112 partitioned into the mover accommodating space and the lower partition walls 13 and 113 are formed.

In addition, focusing holes 13a and 113a are formed in the lower partitions 13 and 113 to communicate the mover accommodation spaces 11 and 111 and the image sensor accommodation spaces 12 and 112. IR filter accommodation grooves (not shown) are formed in the side partitions 13 and 113, and foreign material accommodation grooves (not shown) are formed in the partition walls 13 and 113 of the mover accommodation spaces 11 and 111, respectively.

The stator 10 includes a cover 14 in which incident holes 14a and 114a which are incident light entrance paths of a subject are formed, a circuit board on which all or part of actuator control circuits described later are disposed and fixed, and an IR filter. Placement can be fixed by a method such as phosphorus bonding, fastening, bonding, gluing, or fusion.

In the second embodiment of the present invention, as shown in Figs. 8 to 9, the stator 110 is constituted by a pair of divided bodies 110A and 110B divided based on the optical axis CL, and the pair of divisions is performed. In the bodies 110A and 110B, the partition wall 114 having the divided entrance hole 114a is formed, and the partition wall 113 having the focus hole 113a and the IR filter accommodating groove (not shown) are formed.

In addition, a method of forming and engaging the engaging projections 110c and the engaging grooves 110d among the structural arrangement fixing means is applied to the opposing surfaces of the divided bodies 110A and 110B facing each other, and a pair of divided bodies ( 110A and 110B form one stator 110 through which the mover accommodating space 111, the image sensor part accommodating space 112, the IR filter accommodating groove, the incident hole 114a, and the focus hole 113a are formed. do.

Accordingly, the camera module actuators 1 and 100 according to the first and second embodiments of the present invention are incident through the entrance holes 14a and 114a formed in the upper partition walls of the mover accommodation spaces 11 and 111. The incident light of the subject is converted into the focus light while passing through the lens L mounted on the movers 20 and 120, and passes through the focus holes 13a and 113a and the IR filter F formed on the lower partition wall surface, thereby IR filtering. The focused light is configured to reach the image sensor unit 300.

The image sensor unit 400 includes an image sensor 420 for converting IR filtered focus light into image data; And a circuit board 410 which provides an electrical connection state to the optical device circuit as described below, and converts the image data converted by the image sensor into image image data in a standardized format that can be reproduced by the image device. The apparatus may further include an image sensor processor configured to transmit and receive data and commands to and from an external circuit including a main processor (multiprocessor-applied optical device) and serve as a control unit of an actuator unit control circuit.

On the other hand, in the present invention, the stator (10, 110) to shield the inflow of the external magnetic field, the permanent magnetic field of the permanent magnet leaked to the outside of the stator to increase the strength of the permanent magnetic field of the permanent magnet directed to the coil magnetic portion Brackets (15, 115, or yokers) made by bending both ends of the metal piece of magnetic material are fixed.

The brackets 15 and 115 are preferably molded integrally with the stators 10 and 110 through insert injection molding, and both ends of the brackets 15 and 115 disposed on the stators 10 and 110 are bent. The fixed shaft portions 15a and 115a parallel to the optical axis CL are formed, respectively.

In a first embodiment in which one mover 20 is accommodated in the mover accommodation space 11 to perform an auto focus (AF) function, as shown in FIGS. 1 to 4, the inner wall of the stator 10. The bracket 15 formed with the fixed shaft portion 15a is arranged to be fixed.

In the second embodiment in which the pair of movers 20 are accommodated in the mover accommodation space 11 to perform an optical zoom function, as shown in FIGS. 8 to 10, the split body forming the stator 110. The brackets 115 having the fixed shaft portions 115a are disposed and fixed to the 110A and 110B, respectively, and the fixed shaft portions 115a are formed on both inner walls of the stator 110 formed through the engagement of the divided bodies 110A and 110B. The brackets 115 are arranged to be fixed.

Meanwhile, the mover accommodation spaces 11 and 111 formed in the stator 10 and 110 accommodate the movers 20 and 120 made of an injection molding, and the lens accommodation space 21 is provided in the mover 20 and 120. At least one lens L is mounted in the lens accommodation space 21 through a lens assembly structure described later.

In the first embodiment of the present invention, as shown in FIG. 4, the lens barrel 22 is formed on the inner wall of the lens accommodating space 21, and the lens barrel 22 accommodating at least one lens L is provided in the lens accommodating space 21. The lens fastening structure using the lens barrel 22 which is fastened by the screw fastening method to a) is fixed.

In the second embodiment of the present invention, as shown in FIG. 10, at least one lens L is introduced into the lens accommodating space 121 formed in the mover 20, and then the lens accommodating space 121 is provided through the lens holder 122. It adopts a lens assembly structure configured to close the entrance of the).

By adopting the lens assembly structure in which the lens barrel is removed as in the second embodiment, it is possible to reduce the volume and weight of the mover according to the installation of the lens barrel, and to manufacture the lens barrel and separately assemble the lens in the lens barrel. It can reduce the incidental cost and increase of foreign matters caused by the increase of manufacturing man-hours.

In addition, when the IR filter F, which is attached and fixed to the IR filter accommodating groove of the stator, is assembled into the lens accommodating space 122 of the mover 120 in which the lens is accommodated, the incident cost and foreign substances can be reduced. .

In the movers 20 and 120 accommodated in the mover accommodation spaces 11 and 111 of the stator 10 and 110, moving shaft portions 23 and 123 parallel to the optical axis of the stator are formed, respectively.

As shown in FIGS. 3, 4, and 10, the movers 20 and 120 accommodated in the mover accommodation spaces 21 and 121 are stators 10 and 110 through moving shaft portions 23 and 123 formed at both edges of the mover. ) Is supported by contact with the fixed shaft portions 15a and 115a (line or surface contact).

If necessary, a plurality of steel balls (ball bearings) are inserted (not shown) into the fixed shaft portion and the moving shaft portion, so that the fixed shaft portion and the moving shaft portion are configured to be supported by making a plurality of point contact states through the steel ball balls. It is possible.

In addition, as described later, the stator 10 and 110 and the mover 20 and 120 contacted and supported through the fixed shaft portions 15a and 115a and the moving shaft portions 23 and 123 may be permanent magnets of the actuator portion 200. When the 210 and the coil magnetic part 220 are selectively disposed, a magnetic force (gravitation force acting between the permanent magnet and the magnetic body) is formed between the permanent magnetic field of the permanent magnet 210 and the magnetic body 222 of the coil magnetic part 220. The support force acts by the) and the fixed shaft portions 15a and 115a and the movable shaft portions 23 and 123 are stably contacted to maintain the supporting state.

The movers 20 and 120 accommodated in the stator 10 and 110 are spaced apart from the moving shaft portions 23 and 123 and the partition wall by an air gap, and are configured to have a non-friction state with the inner walls of the stator 10 and 110. do.

In addition, when a lubricant is applied between the fixed shaft portions 15a and 115a and the movable shaft portions 23 and 123 in contact with the line or surface, the friction force generated therebetween is reduced, and the shaft portion is deformed due to excessive friction. As the operation characteristics of the ruler are rapidly changed or a large amount of foreign matter is generated, the foreign matter generated by the friction is adsorbed by the surface tension of the lubricant, so that the foreign matter does not diffuse into the mover accommodation spaces 11 and 111. In addition, the disturbance of the image quality of the camera module due to the spread of foreign matter is prevented.

On the other hand, the actuator portion 200 is disposed between the inner wall of the stator (10, 110) and the outer wall of the mover (20, 120) supported through the fixed shaft portion (15a, 115a) and the moving shaft (23, 123), Permanent magnet 210 formed to be partitioned by the magnetic pole separation line 213, the N-polar portion 211 and the S-polar portion 212 on one surface, and the coil magnetic portion 220 disposed to face the permanent magnet 210 It is configured to include.

In addition, the permanent magnet 210 may be configured such that the N-polar part and the S-polar part are formed on one surface by attaching a pair of permanent magnets, but in the present invention, the N-polar part 211 is formed on one surface by a two-pole magnetization method. And the S-polar part 212 is adopted to the permanent magnet 210 of a single body formed to be partitioned.

At this time, it is preferable to partially mark the permanent magnet with an oil pen, an oil paint, etc., so that the worker may confuse the polarity during the manufacturing process and assemble the wrong magnet.

Coil 221 constituting the coil magnetic part 220 is usually made of copper wire of enamel coating, it is also possible to adopt a mesmer coil applying the MEMS method.

And, the magnetic body 222 of the coil magnetic part is preferably composed of a metal plate made of a magnetic material, but may be formed by applying magnetic powder for miniaturization of the volume, and the coil may be made of a magnetic material so that the coil serves as a magnetic material. It is also possible to have.

As shown in FIGS. 1 to 8, the permanent magnet 210 is disposed and fixed to the inner wall of the stator 10, and the coil magnetic part 220 is disposed and fixed to the outer wall of the mover 20 facing the mover 20 and the mover 20. Coil magnetic part movable actuator arrangement arrangement structure in which the coil magnetic part 220 is displaced together is adopted.

Referring to the drawings, the permanent magnet 210 is disposed and fixed on the inner wall surface of the bracket 15 fixed to the injection molding by insert injection molding on the stator 10, and the magnetic circuit configuration of the bracket 15 of the magnetic material (role of yoker). The permanent magnetic field of the permanent magnet 210 is configured to be directed to the coil magnetic part 220.

In addition, the movable part 20 is fixed to the magnetic part 222 made of a metal piece of magnetic material through insert injection molding, and the coil adhesion protrusion 24 is formed on the outer wall of the movable part 20 on which the magnetic part 222 is disposed and fixed. ) To bond the hollow part of the coil 221 through the coil abutment protrusion 24, and the coil magnetic part 220, which consists of the coil 221 and the magnetic part 222, is fixed to the outer wall of the mover 20. Be sure to

As shown in FIGS. 8 to 13, the permanent magnet 210 is disposed and fixed on the outer wall of the mover 120, and the coil magnetic part 220 is disposed and fixed on the inner wall of the stator 110 facing the mover 120 to permanently move with the mover 120. The magnet 210 adopts a permanent magnet movable actuator arrangement arrangement in which the magnet 210 is displaced together.

In the present embodiment, the coil magnetic part 220 is disposed on the bracket 115 fixed to one side of the stator 110 and the bracket 115 fixed to the other side, and accommodated in the mover accommodation space 111. The permanent magnets 210 are disposed and fixed to the pair of movers 120, respectively.

When the coil magnetic part 220 is disposed on the inner wall surface of the bracket 115 as in the present embodiment, the magnetic part 222 constituting the coil magnetic part 220 is disposed on and fixed to the stator 110. Can be replaced by 115.

Accordingly, the coil 221 of the coil magnetic part 220 is fixed to the inner wall of the bracket 115 made of a magnetic material, and the coil magnetic part 220 using the bracket 115 as a magnetic part on the inner wall of the stator 110 is formed. Placement is fixed.

Therefore, as shown in FIGS. 1 to 13, the mover 120 accommodated in the mover accommodation space 111 of the stator 110 is driven by a force acting between the permanent magnetic field of the permanent magnet 210 and the coil magnetic part 220. Displacement movement, and position maintenance of the mover 20 are implemented.

Figure 14 shows a control circuit for controlling the actuator portion of the actuator for the camera module according to the present invention.

As shown in Fig. 14, the control circuit includes an operation unit 311 which is an external input means for requesting a displacement change request; A memory unit 312 in which a program or data is stored; A controller 310 for controlling a displacement change operation corresponding to the request command according to a program of the memory unit 312 or a displacement change request command through the operation unit 311; The driving circuit unit 320 is configured to change the direction of supply of current to the coil 221 and to supply or turn off the current to the coil 221 according to the control signal of the controller 310.

In addition, the control circuit is an electrical connection state is formed through the circuit board 330 including the F-PCB, PCB, etc. to provide an electrical connection state with the coil 221 of the coil magnetic portion.

The driving circuit unit 320 may include an H-bridge circuit (or a full bridge circuit) 321 for changing a current supply direction to the coil 221 according to a control signal of the controller 310; It is configured to include a constant voltage source 322 to supply (ON) or cut off (OFF) the current to the coil 221.

In addition, in the pulse width modulation method that outputs high power, when Fourier transformed, noise of high frequency component is radiated to the outside to reduce the reception sensitivity of wireless communication equipment, and when the current of pulse component is supplied to the coil, back EMF Because of this, the optical device power supply may be unstable, so connect one or more capacitors C _{1 and} C ₂ between the output terminal of the driving circuit portion and the ground of the circuit board _, and the total capacitance of these capacitors is 10pF or more. It is configured to be the following value.

In addition, the actuator unit 200 is an electromagnetic force applied between the electromagnetic field generated in the coil 221 and the permanent magnetic field of the permanent magnet 210 divided into the N-polar part and the S-polar part when a current is supplied to the coil of the coil magnetic part ( Displacement movement of the movers 20 and 120 including the redirection is realized by the repulsive force in the same polarity and the attraction force in the other polarity, and when the current supply is cut off, the magnetic body 222 of the coil magnetic part 220 and the permanent body are permanent. The maintenance of the position of the movers 20 and 120 is realized by the magnetic force (gravity between the permanent magnet and the magnetic body) applied between the permanent magnetic fields of the magnet 210.

In detail, when a current in a forward direction (clockwise) is supplied to the coil 221 of the coil magnetic part 220, an S-polar electromagnetic field is generated in a coil facing the permanent magnet 210, and in a reverse direction (counterclockwise). Direction) is supplied, the coil is manufactured and arranged so that an N-polar electromagnetic field is generated in the coil facing the permanent magnet 210.

When a displacement movement command is input to the controller 310 in the upward direction (forward or subject direction) along the optical axis by the program stored in the operation unit 311 or the memory unit 312, The controller 310 outputs a control signal for supplying a reverse current, and the driving circuit 320 supplies a reverse current to the coil 221 of the coil magnetic part 220.

Thus, as shown in FIGS. 5 and 11, an N-polar electromagnetic field is generated in the coil 221 facing the permanent magnet, and the N-polar electromagnetic field and the permanent magnetic field of the permanent magnet 210 partitioned into an N-polar part and an S-polar part. The electromagnetic force is generated between the movers 20 and 120 are displaced in the upward direction.

On the contrary, when a displacement movement command is inputted to the controller 310 in the downward direction (rearward or image sensor direction) by the program stored in the operation unit 311 or the memory unit 312, The control unit 310 outputs a control signal for supplying current in the forward direction, and the driving circuit unit 320 supplies the forward current to the coil 221 of the coil magnetic unit 220.

Therefore, as shown in FIGS. 6 and 12, the S-polar electromagnetic field is generated in the coil 221 facing the permanent magnet, and the S-polar electromagnetic field and the permanent magnetic field of the permanent magnet 210 divided into the N-polar part and the S-polar part. The electromagnetic force is generated between the movers 20 and 120 are displaced in the downward direction.

At this time, when the strength of the electromagnetic force for the displacement movement of the mover (20, 120) is greater than the combined force of the physical force, including gravity and friction, and the magnetic force applied between the permanent magnet and the magnetic body, the displacement movement of the mover is stable Is performed.

When the control unit 310 outputs a control signal to cut off the current supply, the driving circuit unit 320 cuts off the current supplied to the coil 221 of the coil magnetic unit 220 so that the electromagnetic field generated in the coil is extinguished. As a result, as shown in FIGS. 7 and 13, the movers 20 and 120 move the moving shaft part 123 by a magnetic force applied between the magnetic body 222 of the coil magnetic part 220 and the permanent magnetic field of the permanent magnet 210. It is supported by the fixed shaft portion 115a and maintained in position.

Therefore, the moving force for displacement movement of the movers 20 and 120 acts between the electromagnetic field generated by the coil 221 of the coil magnetic part 220 and the permanent magnetic field emitted by the permanent magnet 210 by the current supply. Depending on the electromagnetic force, the stopping force for maintaining the position of the displacement mover (20, 120) is dependent on the magnetic force acting between the permanent magnetic field and the magnetic portion 222 emitted from the permanent magnet (210).

In addition, the bearing force of the fixed shaft portion (15a, 115a) and the moving shaft portion (23, 123) is in accordance with the magnetic force acting between the permanent magnetic field of the permanent magnet 210 and the magnetic portion 222 of the coil magnetic portion 220, The strength of the magnetic force for maintaining the position and supporting force of the movers 20 and 120 is greater than the force of the physical force including gravity and friction force and the external force applied to the actuator from outside, and the mover is supported on the shaft. It remains stable against external force.

Thus, in the present invention, the actuator unit is driven in accordance with the control signal of the control unit, so that the displacement movement and position maintenance for moving the mover 20, 120 and the lens L mounted thereon forward or backward along the optical axis CL can be performed. Is performed.

Then, the auto focus (AF) function for adjusting the focal length between the lens and the image sensor according to the position of the subject by the displacement movement and the position of the lens-mounted mover, or the distance between the lens and the lens Optical zoom function to adjust the zoom ratio is performed.

Figure 15 shows the movement distance characteristics of the mover (or mounted lens) of the actuator for the camera module according to the present invention, the pulse width modulation (Pulse Width Modullation, PWM) which is a method of blocking the supply of current through the drive circuit unit to the coil It can be seen that it is a stepping displacement movement characteristic in which the displacement movement and the position maintenance of the mover are performed according to the method.

The movement distance output characteristic of the mover equipped with the lens for the pulse width modulation method (PWM) is that the longer the pulse width, which is the time for supplying the current to the coil, the longer the displacement movement distance of the mover with respect to one pulse width is obtained. If this is short, the displacement travel distance of the mover for one pulse width becomes F; According to the number of pulses having the same pulse width (unit pulse width), the movement distance of the mover equipped with the lens becomes the accumulation amount of the unit displacement movement distance with respect to the accumulation amount of the unit pulse number.

Accordingly, the controller may control the focal length or the zoom magnification by controlling the displacement distance of the mover by controlling the pulse width and the number of pulses, which is a time for supplying current to the coil.

The implementation process of the auto focus (AF) function or the optical zoom function through the control circuit, according to the request command of the program or the operation unit, the control unit and the direction designation of the current supplied to the coil of the coil magnetic unit The control signal for supplying or interrupting current is output to the driving circuit unit 320.

The driving circuit unit 320 supplies or cuts a current in a direction specified to the coil 221 of the coil magnetic unit 220, and the actuator unit moves and shifts the movement of the lens-mounted mover in the displacement direction specified by the controller. To provide a stopping force (including support force) to hold the moved mover in position.

Therefore, the mover equipped with the lens according to the direction specified by the control unit realizes displacement movement and position maintenance with a stepped displacement characteristic moving forward or backward along the optical axis, and as a result, the focus between the lens and the image sensor according to the position of the subject Auto Focus (AF) function to adjust the distance or Optical Zoom function to set the zoom ratio by adjusting the distance between the lens and the lens is implemented.

On the other hand, the optical device circuit to which the actuator for the camera module according to the present invention is applied comprises the control circuit, the image sensor, the image sensor processor, and the main processor unit (when the optical device is a multiprocessor configuration).

In the optical device circuit, a processor (image sensor processor or main processor) performs the operation and role of the control unit of the control circuit described in the description of the actuator unit, and the optical device circuit is composed of individual circuits or individual circuits. It can be grouped to form an integrated circuit (IC).

In addition, a circuit board that mounts and secures the optical device circuit and provides an electrical connection state between the optical device circuits may be separated into a plurality of circuit boards, and the optical device circuits may be selectively mounted and fixed on the plurality of circuit boards. have.

In addition, as a means for providing an electrical connection state between the coil and the circuit board, the circuit board and the selection circuit, the circuit board and the circuit board to provide an electrical connection state by applying soldering, welding, the use of a connector, the use of a wireless transmission device. Can be.

In addition, some of the plurality of circuit boards in which the circuit is mounted and fixed (a driver circuit board electrically connecting the coil and the driving circuit unit and an image sensor unit circuit board in which the image sensor unit is mounted and fixed) may have an inner wall surface or an outer wall surface of the stator. It can be fixed by applying a fastening, fastening, fusion, bonding, use of adhesives, etc. as a means for fixing the structural arrangement.

On the other hand, the spirit and contents of the present invention have been described in detail through the drawings and the description in the specification, and specific terms have been used herein, but only those used for the purpose of describing the present invention are limited to the meanings and the contents described in the claims. It is not used to limit the invention.

Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this, and the true technical protection scope of the present invention is the technical spirit or essential features of the appended claims. Should be decided by

Since the actuator for a camera module according to the present invention can be manufactured in a very small size, it can be utilized in various optical device fields in which a small camera module or a small camera module is mounted.

Claims (11)

1. A stator having a mover accommodation space formed therein; At least one mover housed in the stator and mounted with a lens; An actuator part disposed between the stator and the mover to provide a moving force for displacement movement along the optical axis, and a stopping force for maintaining the position of the displacement-moved mover,

   The actuator unit comprises: a coil magnetic unit comprising a coil for generating an electromagnetic field when supplying a current, a magnetic body for applying a permanent magnetic field and a magnetic force of the permanent magnet; It consists of a permanent magnet formed to partition the N-polar part and the S-polar part, the permanent magnet and the coil magnetic part constituting the actuator portion is configured to be alternatively disposed on the inner wall of the stator and the outer wall of the mover to face each other,

   The moving force for displacement movement of the mover depends on the electromagnetic force acting between the electromagnetic field generated when the current is supplied from the coil of the coil magnetic part and the permanent magnetic field of the permanent magnet, and the stopping force for maintaining the position of the displaced mover is the coil magnetic part. Is configured to comply with the magnetic force acting between the permanent magnetic field of the permanent magnet and the magnetic material of the coil magnetic part by cutting off the current in the coil,

   The permanent magnet or the coil magnetic part may be configured to have a fixed shaft portion at both ends of the inner wall of the stator, and the outer wall of the mover to face the movable shaft portion, the mover accommodated in the receiving space of the stator has a fixed shaft portion and the moving shaft portion Are supported in contact with each other through

   The support force between the fixed shaft portion and the moving shaft portion is configured to correspond to the magnetic force applied between the permanent magnetic field of the permanent magnet and the magnetic body of the coil magnetic portion.
2. The actuator of claim 1, wherein the permanent magnet of the actuator part is disposed on an inner wall of the stator, and a coil magnetic part consisting of a coil and a magnetic body is disposed and fixed on an outer wall of the mover facing the stator.
3. The method according to claim 1 or 2, wherein the metal piece of magnetic material is placed and fixed to the mover through insert injection molding, and a coil abutment is formed on the outer wall of the mover on which the metal piece of magnetic material is arranged and fixed to form a coil abutment protrusion and a coil. An actuator for a camera module, characterized in that the coil magnetic portion is formed by attaching the hollow portion so that the coil magnetic portion is disposed and fixed to the mover.
4. The actuator of claim 1, wherein the permanent magnet of the actuator unit is disposed and fixed to an outer wall of the mover, and a coil magnetic part consisting of a coil and a magnetic body is fixed to the inner wall of the stator facing the mover.
5. According to claim 1, wherein a bracket made of a metal material of a magnetic material is installed to the stator by insert injection molding, both ends of the bracket is bent to form a fixed shaft portion, the inner wall surface of the bracket permanent magnet, or coil of the actuator An actuator for a camera module, wherein any one of the coils of the magnetic part is alternatively fixed.
6. The actuator for a camera module according to claim 1, wherein the permanent magnet formed by partitioning the N polarity part and the S polarity part on one surface thereof is manufactured by a one-pole dipole magnetization method.
7. The lens of claim 1, wherein a lens receiving space is formed in the mover, the at least one lens enters through the entrance of the lens receiving space, and then the lens holder is closed by closing the entrance of the lens receiving space through the lens holder. Actuator for a camera module, characterized in that the mounting is fixed.
8. The actuator of claim 7, wherein an IR filter is accommodated in the lens accommodation space of the mover in which the lens is accommodated.
9. The apparatus according to claim 1, further comprising: an operation unit which is an external input means for requesting a displacement change request; A memory unit in which a program or data is stored; A control unit controlling a displacement change operation corresponding to the request command in accordance with a program of the memory unit or a displacement change request command through the operation unit; A driving circuit unit which changes the direction of supply of current to the coil and supplies current to the coil (ON) or cuts off (OFF) according to a control signal of the controller; In the control circuit configured to mount and fix the circuit, and to provide an electrical connection state between the circuits, the coil of the magnetic part of the coil magnetic part is configured to be electrically connected to the output terminal of the driving circuit part.

   The control unit outputs a direction signal of the current supplied to the coil of the magnetic coil of the coil and a control signal for supplying or cutting off the current to the driving circuit unit according to a request command of a program or an operation unit,

   The driving circuit part supplies or cuts a current in a direction specified by the coil of the magnetic part of the coil according to a control signal, so that the actuator part maintains the movement force for displacement movement and the position of the displaced mover in the direction specified by the controller. Stopping force is generated for

   The lens-mounted mover moves forward or backward along the optical axis by the moving force and the stopping force generated by the actuator in the direction specified by the control unit, and performs displacement movement and position maintenance, so that the focal length or between the lens and the lens Actuator for a camera module, characterized in that configured to adjust the interval.
10. 10. The apparatus of claim 9, wherein the driving circuit unit comprises: a bridge circuit for changing a supply direction of current to the coil; Actuator for a camera module comprising a constant voltage source for supplying (ON) or off (OFF) current to the coil.
11. 10. The method of claim 9, wherein one or more capacitors are connected between an output terminal formed on the driving circuit unit and a ground of the circuit board, and the sum of the capacitances of the one or more capacitors is 10 pF to 5 kΩ or less. Actuator for a camera module characterized by.

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