KR101036010B1 - camera module - Google Patents

Abstract

A camera module is disclosed. The camera module includes a lens barrel that is moved forward or backward in the optical axis direction; A forward driving force fixedly installed at one side of the lens barrel, the first magnet having an inclined surface inclined with respect to the optical axis direction, and disposed in a magnetic field region formed by the first magnet to move the lens barrel forward when power is applied. A first actuator comprising a first coil for providing a first yoke and a first yoke disposed opposite to the first magnet and provided with the first coil on a side opposite to the first magnet; And a second magnet fixed to one side of the lens barrel adjacent to the first magnet and having an inclined surface inclined with respect to an optical axis direction, and disposed in an area of a magnetic field formed by the second magnet to apply power. A second actuator including a second coil providing reverse driving force for reversing the lens barrel, and a second yoke disposed opposite to the second magnet and provided with the second coil on a side opposite to the second magnet; And the forward driving force and the backward driving force, respectively, include a parallel component parallel to the optical axis and a vertical component acting in a direction perpendicular to the optical axis and adjacent to the optical axis. Accordingly, since the forward driving force and the backward driving force include a component that reduces the friction of the lens barrel, the friction of the lens barrel can be effectively reduced.

Camera Modules, Actuators, Slopes

Description

Camera module

The present invention relates to a camera module.

In general, according to the development of the manufacturing technology of a mobile communication terminal equipped with a digital camera or a camera module, a small, lightweight camera module is provided.

In addition, as the camera module package for mobile devices has recently become high pixel and highly functional, rapid technological development is underway to have similar performance to that of general high-end digital cameras, and in particular, attempts to implement auto focusing technology in mobile size Is multifaceted.

Actuators that enable this auto focusing technique include voice coil actuators (VCA) that largely use Lorentz force and piezo actuators that use piezoelectric piezoelectric effect.

In the case of a camera module including a conventional voice coil actuator, the lens barrel is slidably installed on a shaft extending in the optical axis direction inside the housing to move the lens barrel forward or backward in the optical axis direction, or a ball is provided between the inner portion of the housing and the lens barrel. Interpose.

However, when the lens barrel is moved forward or backward in the optical axis direction in this way, the friction between the shaft or the ball and the lens barrel not only requires a large driving force to drive the lens barrel, but also increases the hysteresis and thus the position sensor. It is difficult to apply to camera auto focusing without.

To solve this problem, the friction is reduced by using a lubricant or grease, which can reduce the friction, thereby reducing the hysteresis, and through servo control, accurate position control and auto focusing are realized.

However, when using lubricants and greases, there is a problem that additional processes occur, manufacturing costs increase, and additional management is required. Moreover, when using a position sensor, there exists a problem that manufacturing cost increases and reliability falls.

The present invention provides a camera module configured to reduce friction generated when the lens barrel is moved forward or backward.

According to an aspect of the invention, the lens barrel to move forward or backward in the optical axis direction; A forward driving force fixedly installed at one side of the lens barrel, the first magnet having an inclined surface inclined with respect to the optical axis direction, and disposed in a magnetic field region formed by the first magnet to move the lens barrel forward when power is applied. A first actuator comprising a first coil for providing a first yoke and a first yoke disposed opposite to the first magnet and provided with the first coil on a side opposite to the first magnet; And a second magnet fixed to one side of the lens barrel adjacent to the first magnet and having an inclined surface inclined with respect to an optical axis direction, and disposed in an area of a magnetic field formed by the second magnet to apply power. A second actuator including a second coil providing reverse driving force for reversing the lens barrel, and a second yoke disposed opposite to the second magnet and provided with the second coil on a side opposite to the second magnet; Wherein the forward driving force and the backward driving force are each provided with a parallel component parallel to the optical axis and a vertical component acting in a direction perpendicular to the optical axis and adjacent to the optical axis.

 The first yoke may include a first yoke inclined surface parallel to an inclined surface of the first magnet on a side facing the first magnet.

The first yoke may have a plane parallel to the optical axis on the side opposite to the first magnet.

The second yoke may include a second yoke inclined surface parallel to the inclined surface of the second magnet on a side facing the second magnet.

The second yoke may have a plane parallel to the optical axis on a side opposite to the second magnet.

According to a preferred embodiment of the present invention, the forward drive force and the reverse drive force provided by the first actuator and the second actuator respectively include components that reduce the friction of the lens barrel, thereby effectively reducing the friction of the lens barrel.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in the following description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals and redundant description thereof will be omitted. Shall be.

1 is an exploded perspective view of a camera module according to an embodiment of the present invention. Where F represents the front and L _a represents the optical axis.

Referring to FIG. 1, the camera module 100 according to the present embodiment may include a lens barrel 110, a first actuator 130, and a second actuator 150.

The lens barrel 110 may include at least one lens (not shown) therein and may move forward or backward in the optical axis direction to focus the image.

According to the present embodiment, the lens barrel 110 may receive the forward driving force from the first actuator 130 and move forward in the optical axis direction. The first actuator 130 may include a first magnet 132, a first coil 134, and a first yoke 136.

The first magnet 132 may be fixedly installed on one side of the lens barrel 110. In this case, one side of the first magnet 132 may be installed in the first magnet accommodating part 111 provided on one side of the lens barrel 110.

 The first magnet 132 may have an inclined surface 132a inclined with respect to the optical axis direction. The inclined surface 132a is provided on the other side of the first magnet 132. The first magnet 132 forms a magnetic field region to have a line of magnetic force flowing in or out of the direction perpendicular to the inclined surface 132a.

The first coil 134 may be disposed in the magnetic field region of the first magnet 132. When the power is applied to the first coil 134, a current flows so that Lorentz force is generated.

The power of Lorentz generated when power is applied to the first coil 134 serves as a forward driving force for advancing the lens barrel 110 in which the first magnet 132 is fixed. According to the present embodiment, this forward driving force not only advances the lens barrel 110 but also reduces friction between the lens barrel 110 and the ball 170 to be described later. The forward driving force generated by the first coil 134 will be described later.

The first yoke 136 may be disposed to face the first magnet 132. In this case, the first coil 134 may be installed on the side of the first yoke 136 that faces the first magnet 132.

The first yoke 136 may include a first yoke inclined surface 136a parallel to the first magnet 132 on a side opposite to the first magnet 132. Accordingly, the magnetic field region formed on the inclined surface 132a of the first magnet 132 may be uniformly formed by the first yoke inclined surface 136a opposite to the inclined surface 132a of the first magnet 132. have.

However, this is only an example, and the first yoke may be variously modified, such as having a plane parallel to the optical axis or a curved surface on the side opposite to the first magnet.

An attraction force is generated between the first yoke 136 and the first magnet 132. This attraction increases friction between the lens barrel 110 and the ball 170 when the lens barrel 110 in which the first magnet 132 is fixed moves forward on the optical axis.

According to this embodiment, some components of the forward driving force by the first coil 134 act in a direction to cancel the attraction force generated between the first magnet 132 and the first yoke 136, the lens barrel 110 ) And the ball 170 may be reduced.

According to the present exemplary embodiment, the lens barrel 110 may receive the driving force from the second actuator 150 and move backward in the optical axis direction. The second actuator 150 may include a second magnet 152, a second coil 154, and a second yoke 156.

The second magnet 152 may be fixed to one side of the lens barrel 110 adjacent to the first magnet 132. In this case, one side of the second magnet 152 may be installed in the second magnet accommodating part 112 formed at one side of the lens barrel 110.

 The second magnet 152 may have an inclined surface 152a inclined with respect to the optical axis direction. The inclined surface 152a is provided on the other side of the second magnet 152. The second magnet 152 forms a magnetic field region to have a line of magnetic force flowing in or out in a direction perpendicular to the inclined surface 152a.

The second coil 154 may be disposed in the magnetic field region of the second magnet 152. When the power is applied to the second coil 154, a current flows so that Lorentz force is generated.

The power of Lorentz generated when power is applied to the second coil 154 serves as a reverse driving force for reversing the lens barrel 110 in which the second magnet 152 is fixed. According to the present embodiment, this backward driving force not only reverses the lens barrel 110 but also reduces friction between the lens barrel 110 and the ball 170 to be described later. It will be described later.

The second yoke 156 may be disposed to face the second magnet 152. In this case, the second coil 154 may be installed on the side of the second yoke 156 that faces the second magnet 152.

The second yoke 156 may include a second yoke inclined surface 156a parallel to the second magnet 152 on a side opposite to the second magnet 152. However, this is only an example, and the second yoke may be variously modified, such as having a plane parallel to the optical axis or a curved surface on the side opposite to the second magnet.

Referring to FIG. 1, the second yoke 156 may be disposed adjacent to the first yoke 136. According to the present embodiment, the second yoke 156 and the first yoke 136 are separately manufactured and disposed adjacently, but this is merely an example and the second yoke 156 and the first yoke 136 are integrally manufactured. Can be.

According to the present embodiment, the lens barrel 110 because some components of the reverse driving force by the second coil 154 acts to cancel the attraction force generated between the second magnet 152 and the second yoke 156. ) And the ball 170 may be reduced.

Referring to FIG. 1, the camera module 100 according to the present embodiment may further include a housing 170, a filter housing 180, and a ball 190.

The housing 170 is formed such that the lens barrel 110, the first actuator 130, and the second actuator 150 are accommodated therein, and one surface of the rear or side portion may be opened. The rear part may be sealed by a filter housing 190 in which an image sensor (not shown) is mounted, and one side of the side part may be closed by the first yoke 136 and the second yoke 156.

The ball 190 interposed between the lens barrel 110 and the housing 170 may be interposed. When the lens barrel 110 moves forward or backward by the first actuator 130 or the second actuator 150, the lens barrel 110 may move inside the housing 170 by rolling motion of the ball 190. have.

However, in the case of the camera module 100 according to the present embodiment, the lens barrel 110 is moved forward or backward by using the ball 190, but this is only an example, and the lens barrel can be slid to the shaft installed inside the housing. Can be moved forward or backward.

FIG. 2 is a schematic diagram illustrating an arrangement relationship between a lens barrel, a first actuator, and a second actuator included in a camera module according to an embodiment of the present invention, and FIG. 3 is a diagram illustrating a camera module according to an embodiment of the present invention. 4 is a schematic view illustrating the operation of the included first actuator, Figure 4 is a schematic view illustrating the operation of the second actuator included in the camera module according to an embodiment of the present invention.

Referring to FIG. 2, the lens barrel 110, the first actuator 130, and the second actuator 150 are disposed to each other. The lens barrel 110 may move forward or backward in the optical axis La, that is, in the Y-axis direction, and the first actuator 130 may provide a forward driving force for advancing the lens barrel 110 and the second actuator 150. Provides a reverse driving force for reversing the lens barrel 110.

Hereinafter, the operation of the first actuator 130 and the second actuator 150 will be described with reference to FIGS. 3 and 4. First, referring to Figure 3, the first actuator 130 when the power to the first coil 134 is disposed in the magnetic field region of the first magnet (132) having an inclined surface (132a) is the forward driving force (F ₁ ).

This forward driving force F ₁ includes a parallel component F _1Y parallel to the optical axis direction and a vertical component F _1X perpendicular to the optical axis. Here, the parallel component F _1Y of the forward driving force F ₁ purely advances the lens barrel 110 (see FIG. 2). Since the vertical component F _1X of the forward driving force F ₁ acts in the direction adjacent to the optical axis, the friction between the lens barrel 110 and the ball 190 (see FIG. 1) is reduced.

Meanwhile, referring to FIG. 4, when the second actuator 150 is supplied with power to the second coil 154 disposed in the magnetic field region of the second magnet 152a having the inclined surface 152a, the reverse driving force F ₂ is applied. ). In this case, the operation of the first actuator 130 (see FIG. 2) is stopped.

This backward driving force F ₂ includes a parallel component F _2Y parallel to the optical axis direction and a vertical component F _2X perpendicular to the optical axis. Here, the parallel component F _2Y of the reverse driving force F ₂ purely reverses the lens barrel 110 (see FIG. 2). Since the vertical component F _1Y of the reverse driving force F ₂ acts in the direction adjacent to the optical axis, the friction between the lens barrel 110 and the ball 190 (see FIG. 1) is reduced.

As such, the forward driving force F ₁ and the backward driving force F ₂ provided by the first actuator 130 and the second actuator 150 are vertical components F acting in a direction perpendicular to the optical axis and adjacent to the optical axis, respectively. _1X , F _1Y ), the friction between the lens barrel 110 and the ball 190 can be effectively reduced when the lens barrel 110 moves forward and backward.

Accordingly, the camera module 100 according to the present embodiment does not need to use lubricants and greases in order to reduce friction, thereby lowering manufacturing costs, and no additional process occurs and no additional management is required.

Meanwhile, a DC current or a pulse current may be applied to the first coil 134 and the second coil 154 included in the first actuator 130 and the second actuator 150, respectively. .

In particular, when a pulse current is applied, since the vibration is generated in a direction perpendicular to the optical axis of the lens barrel 110 in which the first magnet 132 and the second magnet 152 are fixed, forward movement of the lens barrel 110 and When reversing, friction between the lens barrel 110 and the ball 190 may be effectively reduced.

Such pulsed current may have a square wave or similar waveform.

5 to 7 are schematic views showing a camera module according to another embodiment of the present invention. The camera modules 200, 300, and 400 illustrated in FIGS. 5 to 7 may compare the first and second actuators 230, 330, and 430 and the second and second actuators 250, 350, and 450, respectively. There is a difference in arrangement, configuration, etc.

However, the camera module 200, 300, 400 according to each embodiment is provided by the first actuator 230, 330, 430 and the second actuator 250, 350, 450, like the previous camera module 100. The forward drive force and the reverse drive force to be included include components that reduce the friction between the lens barrels 210, 310, 410 and the balls (not shown).

Accordingly, the camera modules 200, 300, and 400 according to the embodiments do not need to use lubricants and greases to reduce friction, and thus, manufacturing costs are low, and further processes do not occur and no additional management is required.

Although the preferred embodiments of the present invention have been described above, the spirit of the present invention is not limited to the embodiments presented herein, and those skilled in the art who understand the spirit of the present invention may add components within the same scope. Other embodiments may be easily proposed by changing, deleting, adding, and the like, but this will also fall within the spirit of the present invention.

1 is an exploded perspective view of a camera module according to an embodiment of the present invention,

FIG. 2 is a schematic diagram illustrating an arrangement relationship between a lens barrel, a first actuator, and a second actuator included in a camera module according to an embodiment of the present invention;

3 is a schematic diagram illustrating an operation of a first actuator included in a camera module according to an embodiment of the present invention.

4 is a schematic diagram illustrating an operation of a second actuator included in a camera module according to an embodiment of the present invention.

5 to 7 are schematic views showing a camera module according to another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

110: lens barrel 130: first actuator

132: first magnet 132a: inclined surface

134: first coil 136: first yoke

136a: first yoke slope 150: second actuator

152: second magnet 152a: inclined surface

154: second coil 156: second yoke

156a: second yoke slope 170: housing

180: filter housing 190: ball

Claims (5)

A lens barrel moving forward or backward in the optical axis direction; A forward driving force fixedly installed at one side of the lens barrel, the first magnet having an inclined surface inclined with respect to the optical axis direction, and disposed in a magnetic field region formed by the first magnet to move the lens barrel forward when power is applied. A first actuator comprising a first coil for providing a first yoke and a first yoke disposed opposite to the first magnet and provided with the first coil on a side opposite to the first magnet; And A second magnet fixed to one side of the lens barrel adjacent to the first magnet and having an inclined surface inclined with respect to an optical axis direction, and disposed in an area of a magnetic field formed by the second magnet to apply the power; A second actuator including a second coil providing a reverse driving force for reversing the lens barrel, and a second yoke disposed opposite to the second magnet and provided with the second coil on a side opposite to the second magnet. Including, The forward driving force and the backward driving force respectively include parallel components parallel to the optical axis and vertical components acting in a direction perpendicular to the optical axis and adjacent to the optical axis. The method of claim 1, The first yoke is, And a first yoke inclined surface parallel to an inclined surface of the first magnet on a side opposite to the first magnet. The method of claim 1, The first yoke is, A camera module having a plane parallel to the optical axis on a side opposite to the first magnet. The method according to any one of claims 1 to 3, The second yoke, And a second yoke inclined surface parallel to an inclined surface of the second magnet on a side opposite to the second magnet. The method according to any one of claims 1 to 3, The second yoke, A camera module having a plane parallel to the optical axis on the side facing the second magnet.

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