KR101333185B1 - Auto focus camera module - Google Patents

Abstract

An auto-focus camera module comprises a mover moved in an optical axis of a lens and a stator which moves the mover in the outer periphery of the mover. The mover comprises one or more lenses which are installed inside the mover and collect light; a cylindrical barrel supporting the lenses; a carrier which is attached to the cylindrical barrel and moves the cylindrical barrel upwardly and downwardly; and a magnet. The magnet is fixed on the outer peripheral surface of the carrier and generates a first magnetic field in a horizontal direction. The stator constitutes a magnetic circuit by generating a second magnetic field in the range of the first magnetic field. The stator comprises a coil which is separated from the outer peripheral surface of the magnet and a base supporting the base.

Description

Auto Focus Camera Module {AUTO FOCUS CAMERA MODULE}

The present invention relates to a camera module, and more particularly, to an auto focus camera module having a function of being mounted on a terminal and automatically focusing on a subject.

In general, a camera module mounted in a small terminal such as a digital camera or a mobile phone employs an image sensor such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) to convert an optical signal into an electrical signal. Implement

Such a camera module has an auto focus function that automatically focuses on a subject. To this end, the camera module having an autofocus function is provided with an autofocus control device capable of varying the position of the lens with respect to the image sensor.

The conventional auto focusing apparatus linearly moves a lens in the direction of an optical axis by using a conversion mechanism such as a gear to rotate the motor. However, such an automatic focusing device has a limitation in finely adjusting the focus by using a gear, and is limited in miniaturizing the terminal due to the space occupied by the motor and the gear.

In order to solve such a problem, an auto focusing device of a voice coil motor (VCM) method has been proposed. The VCM type auto focusing device is a method in which a permanent magnet generating a magnetic field is disposed to face a coil to which a current is supplied, thereby changing the position of the lens by a Lorentz force perpendicular to the magnetic field and the current. Here, the coil is connected to the printed circuit board to receive the current.

On the other hand, the VCM type auto focusing device may be configured to move the coil together with the lens while fixing the position of the permanent magnet. In this case, since the coil is moved with respect to the printed circuit board, the wiring terminals drawn out from the coil should be secured in the camera module so that the coil has a length for smoothly moving. For this reason, there is a problem in that the wiring terminals located in the camera module swing when the coil moves. Therefore, the wiring terminals need to be neatly wired. In addition, since the coil is more vulnerable to vibration than the permanent magnet, it is necessary to exclude the vibration effect on the coil.

The object of the present invention is to avoid the difficult task of soldering the coil to the elastic member by coupling the magnet to the mover, and by placing the coil in the stator to neatly wire the wiring terminals, to eliminate the influence of vibration on the coil portion It is to provide a camera module having an auto focus focus function.

In addition, when the magnet located in the mover of the present invention is an integral circular magnet, the magnetic circuit can be configured without the inner yoke, so that the space inside the housing can be reduced, so that the camera module can be miniaturized and the assembly is convenient. In the case of a magnet of the form, it is possible to provide a camera module having a miniaturized magnet, which is advantageous in terms of cost because the magnet is easily manufactured and the unit cost is low.

The autofocus camera module according to the present invention for achieving the above object includes a mover moving in the direction of the optical axis of the lens and a stator for moving the mover from the outer periphery of the mover, the mover is provided therein At least one lens for collecting light, a cylindrical lens barrel for supporting the lens, a carrier bonded to the lens barrel to assist the vertical movement of the lens barrel, and an inner circumferential surface and an outer circumferential surface magnetized to different poles And a magnet fixed to an outer circumferential surface thereof to generate a primary magnetic field in a horizontal direction, wherein the stator generates a secondary magnetic field in a range of the primary magnetic field to form a magnetic circuit, and is spaced apart from an outer circumferential surface of the magnet portion. It characterized in that it comprises a coil provided, and a base for supporting the coil.

In the present invention, it is preferable that the stator further includes a yoke provided on an outer circumferential surface of the coil to serve as a housing, inducing magnetic flux into the housing, and fixed to a base.

In the present invention, the lens barrel is preferably coupled to the carrier in a sliding structure.

In the present invention, it is preferable that a locking end having an inclination is provided on the outer wall of the lens barrel and the inner wall of the carrier corresponding to the outer wall.

In the present invention, the magnet is preferably made of a neodymium material, so as to reduce the load of the mover provided with the magnet.

In the present invention, the magnet is preferably an integral ring type for reducing the leakage magnetic flux.

In the present invention, it is preferable that the magnet is provided with four magnet pieces each having an N pole and an S pole formed in a horizontal direction at an angle of 90 degrees along an outer circumferential surface of the carrier.

In the present invention, the magnet, the S pole surface of the magnet piece is preferably bonded to the outer peripheral surface of the carrier.

In the present invention, it is preferable that the stator further includes a cover formed with an opening to prevent the upper side of the mover.

In the present invention, the mover is joined between the coil and the cover, one end to the upper portion of the carrier and the yoke, which is a mover, so as to be located at an intermediate point of the maximum movable path of the mover when the magnetic circuit is not energized. Preferably, the mover further includes a first elastic member to elastically support the stator.

In the present invention, the mover is joined between the coil and the cover one by one end to the lower portion of the carrier and the yoke, which is a mover, so as to be located at an intermediate point of the maximum movable path of the mover when the magnetic circuit is not energized. Preferably, the mover further includes a second elastic member to elastically support the stator.

In the present invention, it is preferable that the mover automatically focuses while moving up and down along the optical axis according to the direction of current at the intermediate point when the magnetic circuit is energized.

According to the present invention, since the magnet is configured to move together with the lens in a fixed position of the coil, vibration effects on the coil can be excluded.

In addition, the barrel and the mover, which move together with the lens and the magnet part, eliminate the in-yoke configuration by using a radially magnetized magnet, thereby reducing the load of the magnet, and by the strong magnetic field formed thereby. The lighter mover can be moved to focus efficiently.

In addition, it is possible to increase the auto focusing function of the camera module by having a magnet that exhibits more effective properties in terms of shape and material of the permanent magnet of the magnet part.

In addition, it can move the short distance by efficiently moving the position of the mover, and can automatically focus by arranging the elastic force of the elastic member of the upper and lower parts to save the power used for driving the lens, fast and stable The effect of driving can be produced.

1 is an assembled cross-sectional view of the auto focus camera module according to the present invention.
2 is an exploded view of a lens barrel and a carrier according to the present invention.
3 is an exploded perspective view of an auto focus camera module having a quadrangular magnet according to the present invention.
4 is an exploded perspective view of the auto focus camera module having a ring-type magnet according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a cross-sectional view of an auto focus camera module according to an embodiment of the present invention.

1 to 4, the auto focus camera module 100 includes a mover 110 and a stator 120.

The mover 110 includes a lens 111, a lens barrel 112, a carrier 113, a magnet part 114, and an elastic member 115.

The stator 120 includes a coil 121, a cover 122, a base 123, an image sensor 124, and a terminal 126.

The lens barrel 112 includes at least one lens 111. When a plurality of lenses in the lens barrel 112 are configured, the lenses are preferably aligned so that the optical axes coincide. The lens makes an optical image of the subject. The top of the barrel is opened so that light enters the lens. The lower part of the barrel is opened so that light passing through the lens can be transmitted to an image sensor installed under the lens.

The carrier 113 is formed in the cylindrical shape in which the hollow was formed, for example. The carrier 113 is coupled and fixed along the outer circumferential surface of the lens barrel. The carrier 113 combines with the lens barrel and serves to move the lens barrel. In the conventional technology, the lens barrel and the carrier 113 are coupled by a screw thread, but the present invention has a sliding coupling structure. Compared with the screw thread, the joining and detaching are convenient.

The outer wall of the lens barrel and the inner wall of the carrier corresponding to the outer wall are provided with an inclined end. Each of the locking ends formed by the diagonal lines is in the form of meshing with each other, so that when the lens barrel is rotated to fit the carrier, the locking ends are fixed to the locking ends. It is effective in that the manufacturing is simpler and the separation and the coupling are easier than the conventional coupling by the screw. That is, referring to FIG. 2, a locking end having an inclination is provided on the outer wall of the lens barrel and the inner wall of the carrier 113 so that the lens may be rotated 90 degrees and separated.

An upper end and a lower end of the carrier 113 are formed such that an elastic member can be coupled thereto. The elastic member is provided by being divided into a primary and a secondary elastic member, one end of each elastic member is coupled to the end formed in the carrier.

The magnet 114 is fixed to the outer circumferential surface of the carrier 113. The magnet 114 includes a permanent magnet. Permanent magnets can be radial magnetized so that different poles are distributed on the inner and outer circumferential surfaces of the permanent magnet.

3, the inner circumferential surface may be an S pole, and the outer circumferential surface may be an N pole. In general, the magnet yoke is generally installed on the vertical surface leading to the upper side and the upper side of the magnet 114 and the vertical surface leading to the lower side and the lower side. However, in the present invention, since the radial magnetized permanent magnet is used, the distribution of magnetic flux is formed in the circumferential direction from the central axis of the lens bell, so there is no need for the inner magnet yoke and the outer magnet yoke to occupy a certain space, thereby moving the small sized mover. It can manufacture.

The magnet yoke does not exist, but the outer yoke 125 is provided on the outer circumferential surface of the coil to trap the magnetic flux exiting from the central axis of the lens barrel. The outer yoke also serves as a housing. Therefore, it is possible to manufacture a small camera module.

The magnet is fixed to the outer circumferential surface of the barrel while surrounding the lens, i.e. the barrel. If the cross section of the barrel is circular, the permanent magnet may be of a circular ring type. The magnet may be fixed to the barrel by an adhesive or the like while the barrel is fitted.

In FIG. 4, as an embodiment of the present invention, the magnets may be shaped to be provided on one side of a square surrounding the outer circumferential surface of the lens barrel. Like the circumferential magnetizer, the N pole and the S pole may be formed in a horizontal direction so that the S pole may be provided inside and the N pole may be provided outside. The magnet pieces provided on one side of the quadrangle are advantageous in miniaturization of the camera module, and are easy to manufacture and assemble, thus exhibiting various effects as compared with the ring-type magnets.

Like the magnet of the ring-type circumferential magnetizer, since the inner and outer surfaces of the magnet are magnetized to different poles, the magnet yoke does not exist and the outer yog exists to confine the magnetic flux. This is different from the magnet of the upper and lower magnets.

The vertical length of the coil provided to be spaced apart from the outer circumferential surface of the magnet is preferably longer than the vertical length of the magnet, and the outer yoke provided on the outer circumferential surface of the coil is longer than the length of the magnet 114, that is, the upper end of the outer yoke is magnet 114. It is preferable that the upper end of the upper side) and the lower end of the outer yoke are formed lower than the lower end of the magnet 114. This is because the magnetic flux generated in the magnet can sufficiently link with the coil, and can sufficiently collect the magnetic flux that can flow outwards inward.

The outer yoke also serves as a housing. The upper and lower ends of the housing are fixed to the cover and the base 123 between the cover and the base 123, respectively. The housing surrounds and protects the outer surface of the camera module or prevents foreign matter from entering the camera module.

The number of coils 121 may be divided into a primary coil and a secondary coil, but it is preferable that the number of coils is one in a space having a radial magnetized magnet. The coils are spaced apart from the outer circumferential surface of the magnet 114. In addition, the coil 121 may be fixed to the inner circumferential surface of the yoke 125 serving as a housing.

The coil may be formed by winding an electric wire insulated by an enamel resin or the like directly to the inner circumferential surface of the yoke or by winding the wire in a cylindrical shape and then adhering the inner circumferential surface of the yoke with an adhesive or the like.

The coil generates a second magnetic field by the current applied from the outside, and the carrier 113 to which the magnet 114 is fixed by the Lorentz force moves up and down in the optical axis direction according to the direction of the current considering the winding direction of the coil. do. Thus, the position of the lens is varied relative to the image sensor, so that the focus can be automatically adjusted. The coil is supported by the base 123.

The base 123 is formed in a plate shape to fix the stator, and an opening through which light passing through a lens embedded in the lens barrel 112 of the mover is formed in the center portion of the base 123.

Coupling pillars are formed at four corners of the upper surface of the base 123 formed in a plate shape, and the coupling pillar serves to couple the housing.

An image sensor 124 is fixed to a rear surface of the base 123 to generate an image corresponding to the light passing through the lens of the lens barrel 112.

The elastic member includes a first elastic member 115a and a second elastic member 115b. The first elastic member is located between the coil and the cover. The first elastic member is joined and fixed one by one to the upper part of the carrier as the mover and the upper part of the yoke as the stator. With the mover positioned at the midpoint of the mover's maximum movable path when the magnetic circuit is not energized, the first resilient member causes the mover to elastically support the stator.

The second elastic member is also located between the coil and the cover. The elastic member is joined and fixed one by one to the lower part of the carrier which is the mover and the lower part of the yoke which is the stator. In the state where the mover is located at an intermediate point of the mover's maximum movable path when the magnetic circuit is not energized, the second elastic member causes the mover to be elastically supported by the stator.

A gap is formed above the first elastic member and below the second elastic member. The gap corresponds to a free space that allows the mover to move. This is to allow the starting position of the carrier 113, which is the mover, to be formed at the midpoint of the moveable distance of the mover when no current flows in the coil. The mover stationary at the intermediate point moves along the optical axis in the up and down direction according to the direction of the current when current flows through the coil.

In the conventional invention, compared to the mover fixed to the base side while moving the current in only one direction closer to the subject, the moving distance can be shortened by the mover which can move in both directions and can be moved at low power additionally. It is effective because it can focus in a short time.

In addition, since the first elastic member and the second elastic member are disposed in a balanced manner on the moving distance of the mover, it is possible to divide the elastic force acting on each elastic member, thereby acting on the elastic member fixed to one side in the conventional technique. It is possible to prevent distortion of the elastic member due to an unbalanced elastic force.

An embodiment of the present invention will be described. When the inner circumferential surface of the magnet fixed to the outer circumferential surface of the carrier is S pole and the outer circumferential surface is magnetized to the N pole, the magnetic flux starting from the N pole reaches the S pole, so the magnetic field is formed outward from the central axis of the lens barrel. . Since the magnetic field caused by the horizontal magnetic flux generated in the radial magnetized magnet is directly available, it is directly in contact with the magnet to induce the shielding or the direction of the magnetic flux in yoke and out yoke. Can be used to save space in the housing.

Lorentz's force acts on the coil and is fixed by the circumferentially magnetized magnet in the horizontal direction, that is, the coil provided to be spaced apart from the outer circumferential surface of the magnet and the magnetic flux of the primary magnetic field. Since the coil cannot move, an immobilized mover moves along the optical axis to adjust and focus the lens. As the current flows for the first time without current, the mover can move down or up along the optical axis, depending on the direction of the current.

The use of sintered neodymium magnets in one piece of circumferential form is more effective because it can generate a stronger magnetic field than the use of ordinary magnets or pieces of magnet pieces. Although the use of neodymium magnets in one piece requires a complicated process in processing, when the camera module including one magnet piece is constructed using the manufactured neodymium magnets, the convenience of assembling in the assembly line, Better effect in terms of assembly time.

An embodiment of the present invention will be described. When the current is not energized in the coil, the mover is located at an intermediate point on the path where the mover moves by the elastic member. Therefore, the moving distance is shorter than the moving pattern of the conventional rising color by controlling the current direction of the coil to raise and lower the mover. The lens can be focused by moving the mover in a shorter time.

An embodiment of the present invention will be described. In the present invention, since the position at the time of current non-energization of the mover corresponds to an intermediate point on the movement path of the mover, the elastic force applied to the upper elastic member and the lower elastic member can be evenly distributed. Compared to the elastic force concentrated in the elastic member, the effect of reducing power consumption due to the movement of the mover is generated.

As described above, the detailed description of the present invention has been made by the embodiments with reference to the accompanying drawings, but since the above-described embodiments have only been described with reference to the preferred examples of the present invention, the present invention is limited to the above embodiments only. It should not be understood to be limited, and the scope of the present invention should be understood as the following claims and equivalent concepts.

100: autofocus camera module
110: mover
111: lens
112: lens barrel
113: carrier
114: magnet
115a: first elastic member
115b: second elastic member
116a: lens barrel side locking end
116b: carrier end
120: stator
121: coil
122: cover
123: bass
124: image sensor
125: York
126: terminal

Claims (12)

A mover moving in the optical axis direction of the lens; And
A stator for moving the mover on an outer circumference of the mover; Including,
The shifter includes:
At least one lens provided inside to collect light;
A cylindrical lens barrel for supporting the lens;
A carrier bonded to the lens barrel to assist the vertical movement of the lens barrel; And
A magnet magnetized by different poles of the inner circumferential surface and the outer circumferential surface thereof and fixed to the outer circumferential surface of the carrier to generate a primary magnetic field in a horizontal direction; / RTI >
The stator comprises:
A coil configured to generate a secondary magnetic field in a range in which the primary magnetic field affects the magnetic circuit and spaced apart from an outer circumferential surface of the magnet; And
A base supporting the coil; Including,
And an engaging end having an inclination on an outer wall of the lens barrel and an inner wall of a carrier corresponding to the outer wall. The method of claim 1,
The stator comprises:
A yoke provided on an outer circumferential surface of the coil to serve as a housing, inducing magnetic flux into the housing, and fixed to a base; Auto focus camera module characterized in that it further comprises. The method of claim 1,
The lens barrel,
Autofocus camera module characterized in that coupled to the carrier in a sliding structure. delete The method of claim 1,
Wherein the magnet comprises:
Auto focus camera module, characterized in that made of neodymium material to reduce the load of the mover provided with the magnet. The method of claim 1,
Wherein the magnet comprises:
Auto focus camera module, characterized in that the ring-integral type to reduce leakage flux. The method of claim 1,
Wherein the magnet comprises:
Auto magnetization camera module characterized in that the four magnet pieces each formed with the N pole and the S pole in the horizontal direction are provided at an angle of 90 degrees along the outer peripheral surface of the carrier. 8. The method of claim 7,
Wherein the magnet comprises:
The S pole surface of the magnet piece is bonded to the outer peripheral surface of the carrier. The method of claim 2,
The stator comprises:
A cover formed with an opening to prevent the upper side from moving away from the mover; Auto focus camera module characterized in that it further comprises. The method of claim 9,
The shifter includes:
Between the coil and the cover, one end is joined to the upper part of the carrier, which is a mover, and the upper part of the yoke, which is a stator, so that when the magnetic circuit is not energized, it is located at an intermediate point of the maximum movable path of the mover so that the mover is elastic to the stator. A first elastic member to be supported; Auto focus camera module characterized in that it further comprises. The method of claim 10,
The shifter includes:
Between the coil and the cover, one end is joined to the lower part of the carrier, which is a mover, and the lower part of the yoke, which is a stator, so that the mover is elastic to the stator because it is located at an intermediate point of the maximum movable path of the mover when the magnetic circuit is not energized. A second elastic member to be supported; Auto focus camera module characterized in that it further comprises. The method according to claim 10 or 11,
The shifter includes:
Autofocus camera module, characterized in that for automatically focusing while moving the magnetic circuit from the middle point to the vertical direction along the optical axis in the direction of the current.

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