KR102142666B1 - Camera module - Google Patents

Abstract

The present invention relates to a camera module.
That is, the present invention includes a lens and a mover having a first driving unit is formed; A stator in which a second driving unit for driving the mover by electromagnetic force action is formed with the first driving unit; It includes a base to which the stator is fixed, and when the lens is in an up posture or a side posture, the mover contacts the base, and when the lens is in a down posture, the mover It is spaced apart from the base.

Description

Camera module {CAMERA MODULE}

The present invention relates to a camera module.

In recent years, mobile phones and tablet PCs with a miniature camera module have been developed.

In the case of a digital camera module applied to a conventional mobile phone, the distance between an image sensor and a lens that changes external light into a digital image or digital image could not be adjusted, but a voice coil motor and a voice coil motor that adjusts the distance between the image sensor and the lens recently. The same lens driving device has been developed to obtain a better digital image or digital image from a camera module.

In general, a voice coil motor applied to a camera module moves a lens-mounted mover from the base to the top to adjust the distance between the lens and the image sensor disposed at the rear of the base.

The conventional voice coil motor has a structure in which the elastic member presses the mover to contact the base when a drive signal is not applied.

That is, in the conventional voice coil motor, since the elastic member depresses the mover, the electromagnetic force for driving the mover must be greater than the elastic force of the elastic member and the self-weight of the mover in order to move the mover away from the base.

Further, the mover of the conventional voice coil motor has a displacement of about 30 µm to 50 µm depending on the attitude of the voice coil motor.

However, since the mover of the conventional voice coil motor not only has a displacement according to the posture of the voice coil motor, but also includes an undriven section that is not driven even when a drive signal is applied, but the mover is driven by an auto focusing algorithm that does not reflect this, the auto focusing It has a problem that takes a lot of time.

The present invention is to solve the problem that can reduce the current consumption of the camera module.

The present invention,

A mover including a lens and having a first driving portion;

A stator in which a second driving unit for driving the mover by electromagnetic force action is formed with the first driving unit;

The stator includes a base to be fixed,

When the lens is in an up or side posture, the mover contacts the base, and when the lens is in a down posture, the mover is provided by a camera module spaced apart from the base do.

In addition, according to an embodiment of the present invention, the first driving part may be a coiled coil, the second driving part may be a magnet, or the first driving part may be a magnet, and the second driving part may be a coiled coil.

In addition, when the lens is in an up position, when a current less than a reference current is applied to the coil, the mover is not driven, and when a current greater than a reference current is applied to the coil, the mover may be driven.

Also, a start current driving the mover in the side posture may be smaller than a start current driving the mover in the up posture.

In addition, the start current in the side posture may be 0-10 mA.

The present invention,

A mover including a lens and having a first driving portion;

A stator in which a second driving unit for driving the mover by electromagnetic force action is formed with the first driving unit;

The stator includes a base to be fixed,

When the lens is in an up posture, the mover is in contact with the base, and when the lens is in a side posture or a down posture, the mover is provided by a camera module spaced apart from the base do.

In addition, in one embodiment of the present invention, the base is formed in a plate shape having an opening through which light passes in the central portion, and the base serves as a lower stopper of the mover, and an image sensor is disposed on the rear side of the base. The stator may be fixed on the base.

In addition, one side is fixed to the mover and the other side opposite to the one side is fixed to the stator, and may further include an elastic member elastically supporting the mover.

In addition, when the lens is in a down position, the mover may be driven in the reverse direction.

The present invention,

With a mover that includes a lens,

It includes an actuator for driving the mover,

When the lens is in an up or side posture, the mover makes contact with a base serving as a stopper for the mover, and when the lens is in a down posture, the mover is spaced apart from the base Or

Alternatively, when the lens is in an up position, when the mover is in contact with the base, and when the lens is in a side or down position, a camera module provided by the mover apart from the base is provided. do.

In addition, according to an embodiment of the present invention, the actuator may be one of a voice coil motor (VCM) actuator, an actuator driven by piezoelectric power, and a MEMS actuator driven by a capacitive method. .

In addition, a posture detection sensor that outputs posture data by determining one of the up posture, side posture, and down posture of the lens; An image signal processor (ISP) that generates a driving signal for driving the actuator with the attitude data output from the attitude sensor; An image sensor for converting light passing through the lens into a digital signal may be further included.

In addition, the posture sensor may include a gyro sensor that senses the direction of gravity.

Then, when the lens is in a down position, the mover may be driven in the reverse direction.

In addition, when the lens is in the up posture, when the current above the reference current is applied to the coil, the mover may be driven.

The present invention has the effect of detecting the attitude of the voice coil motor or lens, controlling the voice coil motor with this attitude data, reducing the current consumption, and driving the camera module with optimization.

In addition, the present invention reduces the current consumption by removing the mechanical offset (offset) to the actuator, increases the degree of freedom in the design of the electromagnetic force, and applies a current in the opposite direction even if a change in the spring occurs to solve the defocus problem. It can be solved, and there is an effect of improving the yield of the camera module since initial focusing is unnecessary.

1 is a block diagram showing a camera module according to an embodiment of the present invention
Figure 2 is a conceptual cross-sectional view for explaining that the lens of the camera module according to an embodiment of the present invention is located in the upward direction
Figure 3 is a conceptual cross-sectional view for explaining that the lens of the camera module according to an embodiment of the present invention is located in the lateral direction
Figure 4 is a conceptual cross-sectional view for explaining that the lens of the camera module according to an embodiment of the present invention is located in the lower direction
Figure 5 is a graph showing the current-distance characteristics according to the posture of the camera module according to an embodiment of the present invention

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In this process, the size or shape of components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, in consideration of the configuration and operation of the present invention, terms specifically defined may vary according to a user's or operator's intention or practice. Definitions of these terms should be made based on the contents throughout this specification.

1 is a block diagram showing a camera module according to an embodiment of the present invention.

Referring to FIG. 1, the camera module 800 includes a voice coil motor 100 that is driven in one direction, a posture detection sensor 200, an auto focus algorithm 300, an image signal processor 400, an image sensor 500, and It includes a control unit 600.

Here, the voice coil motor 100 includes a mover including a lens and is driven by electromagnetic force to perform auto focusing of the camera module 800.

Then, the posture detection sensor 200 determines the posture of the voice coil motor 100 or the lens and outputs posture data, and the image signal processor (ISP) 400 displays the posture detection sensor ( The posture data corresponding to the posture of the voice coil motor 100 output from 200) is driven to drive the voice coil motor using the optimum focus value of the lens calculated by the autofocus algorithm 300. Generate a signal.

Here, the posture detection sensor 200 may include a gyro sensor that senses the direction of gravity.

In addition, the auto focus algorithm 300 detects an optimal focus value of the voice coil motor 100 according to a distance from a subject and outputs a detection signal in order to accurately implement auto focusing and realize a fast auto focusing response time.

At this time, the auto-focus algorithm 300 may be used in the form of an algorithm inside the image signal processor 400, or may be used embedded in a chip separate from the image sensor processor 400.

Therefore, the posture detection sensor 200 senses three postures of the voice coil motor 100 or the lens, as described below.

Here, the posture detection sensor 200 may sense three or more postures of the voice coil motor 100 or the lens, but in one embodiment of the present invention, for convenience of explanation, the posture detection sensor 200 is a voice coil motor ( 100) Or, it will be described that sensing three postures such as an up posture, a side posture, and a down posture of the lens.

In addition, the image sensor 500 changes the light passing through the lens to a digital signal, the control unit 600 is the voice coil motor 100, the posture detection sensor 200, the image signal processor 400 ) And the image sensor 500.

Then, the control unit 500 is connected to the voice coil motor 100, the posture detection sensor 200, the image signal processor 400 and the image sensor 500 through a data bus and/or a control bus.

Therefore, the present invention has the advantage of detecting the posture of the voice coil motor or lens, controlling the voice coil motor with this posture data, reducing current consumption, and driving the camera module with optimization.

Figure 2 is a conceptual cross-sectional view for explaining that the lens of the camera module according to an embodiment of the present invention is located in the upward direction, Figure 3 is a lens of the camera module according to an embodiment of the present invention is located in the lateral direction It is a conceptual cross-sectional view for explaining, and FIG. 4 is a conceptual cross-sectional view for explaining that the lens of the camera module according to one embodiment of the present invention is located in the lower direction.

As described above, FIG. 2 shows an up posture in which the lens of the camera module is located in the upward direction, and the “up posture” of the lens 135 of the mover 130 of the voice coil motor The optical axis may be defined as a posture formed in a direction perpendicular to the ground and the base 110 disposed to face the ground.

In addition, FIG. 3 shows a side posture in which the lens of the camera module is located in the lateral direction, and the “side posture” is when the optical axis of the lens 135 of the mover 130 of the voice coil motor is grounded. It may be defined as a posture formed in a direction parallel to the base 110 is disposed perpendicular to the ground.

In addition, FIG. 4 shows a down posture in which the lens of the camera module is located in the downward direction, and the “down posture” of the lens 135 of the mover 130 of the voice coil motor 100 The optical axis may be defined as a posture formed in a direction perpendicular to the ground and the cover 150 disposed to face the ground.

Here, the camera module according to an embodiment of the present invention includes a lens 135 and a movable member 130 having a first driving unit 138, and the first driving unit 138 and the electromagnetic force to operate the camera module. A stator 120 in which a second driving unit 125 for driving the ruler 130 is formed, and a base 110 to which the stator 120 is fixed, and the lens 135 is in an up position Or, in the side (side) posture, the mover 130 is in contact with the base 110, and when the lens 135 is in a down posture, the mover 130 is the base 110 ).

In addition , in the case where the lens 135 is in an up posture or a side posture, some offsets exist, and the camera module may include the mover 130 when the lens 135 is in a down posture. ), the offset may be lost due to deflection due to the gravitational direction weight.

In this case, the mover 130, the stator 120, and the base 110 may be parts of the voice motor coil 100.

Referring to FIG. 2, the voice coil motor 100 drives the lens 135 to perform an auto focusing function.

For example, the lens 135 mounted on the voice coil motor 100 is moved in a rising direction from the base 110 and a focusing operation is performed between the lens 135 and the image sensor 500 in this process. Is performed.

The voice coil motor 100 may include a base 110, a stator 120, a mover 130, an elastic member 140 and a cover 150.

In addition, the base 110 is formed in a plate shape having an opening through which light passes in the central portion, and the base 110 serves as a lower stopper of the mover 130.

In addition, the image sensor 500 may be disposed at the rear of the base 110 or the rear of the base 110. The image sensor 500 changes the light focused through the lens of the operator 130 into a digital image or video.

In addition, the stator 120 is fixed on the base 110.

Here, the first driving unit 138 may be a magnet, and the second driving unit 125 may be a wound coil.

Conversely, the first driving unit 138 may be a coil wound, and the second driving unit 125 may be a magnet.

In addition, a storage space may be formed inside the stator 120, and the mover 130 may be located in the storage space.

In addition, one side of the elastic member 140 is fixed to the mover 130 and the other side facing the one side is fixed to the stator 120, so that the elastic member 140 elastically moves the mover 130. Can support.

In one embodiment of the present invention, the elastic member 140 is a first elastic member 143 formed on the lower outer circumferential surface of the movable member 130 and a second elastic member formed on the upper outer circumferential surface of the movable member 130 ( 146).

The elastic member 140 of the second driving unit 125 of the stator 120 and the first driving unit 138 of the mover 130 in an up position in which the lens of FIG. 2 is positioned in an upward direction. When the electromagnetic force is not applied, the mover 130 is brought into contact with the upper surface of the base 110.

That is, when the electromagnetic force of the second driving unit 125 of the stator 120 and the first driving unit 138 of the movable member 130 is not applied, the elastic member 140 may be operated by the movable member 130. By weight, the mover 130 contacts the upper surface of the base 110.

At this time, the voice coil motor 100 feels that the offset between the mover 130 and the upper surface of the base 110 is approximately 0.03 mm.

Therefore, in the camera module of one embodiment of the present invention, the elastic force of the elastic member 140 and the movable member 130 in order to rise from the base 110 in an up position where the lens of FIG. The electromagnetic force greater than the weight of the mover 130 is required.

Then, the cover 150 is fixed to the base 110, the cover 150 surrounds the stator 120 and the mover 130. In addition, the cover 150 serves as an upper stopper for stopping the mover 130.

On the other hand, according to the present invention, when the lens 135 is in an up posture, the mover 130 is in contact with the base 110, and the lens 135 is in a side posture or down. ) In the case of a posture, the mover 130 may be configured to be spaced apart from the base 110.

In addition, the voice coil motor 100 may be applied as an actuator driving a lens of a camera module, an actuator driven by piezoelectric power, or a MEMS actuator driven by a capacitive method.

That is, the actuator for driving the lens of the camera module may be one of a voice coil motor (VCM) actuator, an actuator driven by piezoelectric power, and a MEMS actuator driven by a capacitive method.

Here, the camera module may include a mover 130 including a lens 135 and an actuator that drives the mover 130, wherein the lens 135 is in an up posture. Or, in the case of a side posture, the mover 130 contacts the base 110 serving as a stopper of the mover 130, and when the lens 135 is in a down posture, the When the mover 130 is spaced apart from the base 110, or when the lens 135 is in an up position, the mover 130 is in contact with the base 110, and the lens 135 ) Is a side posture or a down posture, the mover 130 may be configured to be spaced apart from the base 110.

Therefore, the present invention reduces the current consumption by removing the mechanical offset to the actuator, increases the design freedom of electromagnetic force, and applies a current in the opposite direction even if a spring change occurs to solve the defocus problem. It can be solved, and there is an advantage of improving the yield of the camera module since initial focusing is unnecessary.

5 is a graph showing a current-distance characteristic according to a posture of a camera module according to an embodiment of the present invention.

First, referring to the graph of FIG. 5, in the "up (up) posture" of the camera module, the mover contacts the base, and in order for the mover to rise from the base, the elastic force of the elastic member and the electromagnetic force greater than the weight of the mover are applied. As necessary, a reference current or higher should be applied to the driving unit.

Therefore, in FIG. 5, the “up posture” of the camera module has an auto focus search section of the'A' graph.

Accordingly, in FIG. 5, the current is less than the reference current [mA], the mover is not driven, and the current section below the reference current [mA] may be defined as an undriven section in which the mover is not driven. In, since the mover is not driven, an autofocus operation is not performed.

In addition, at a current equal to or greater than the reference current [mA], the electromagnetic force driving the mover is greater than the weight of the mover and the elastic force of the elastic member to drive the mover.

Here, the current section above the reference current [mA] may be defined as a driving section in which the mover is driven, and an autofocus operation is performed only when the mover is driven in the operation section.

In addition, in the "side attitude" of the camera module, the mover is in contact with the base, but the elastic force of the elastic member and the weight of the mover are not taken into account in order for the mover to rise from the base, so current is applied to the mover. From the moment the mover is driven.

Therefore, in the "side attitude" of the camera module, the autofocus search section of the'B' graph in FIG. 5 is obtained.

Here, the voice coil motor arranged in the side posture is driven at a smaller current than the voice coil motor arranged in the up posture.

That is, the start current driving the mover in the side posture is smaller than the start current driving the mover in the up posture.

And, in the "side (side) posture" of the camera module, the start current may be 0-10 ,, and the difference in posture between the "up posture" and "side posture" is about 30~ It may be 50㎛.

In addition, in the case of the camera module's “down posture”, the mover is spaced apart from the base, and the autofocus search section of the'C' graph in FIG. 5 is obtained.

Therefore, in the "down posture" of the camera module, the mover can be driven in the reverse direction.

As shown in FIG. 4, when the mover 130 is in a down posture disposed below the base 110, in the initial state in which no current is applied to the coil, the elastic member 140 has the mover 130 It can be supported so as to be arranged in a first initial position spaced from the base 110. In the down position, when a reverse current is applied to the coil, the mover 130 may move from the first initial position to the direction closer to the base 110.

As shown in FIG. 2, when the mover 130 is in an up posture disposed above the base 110, the mover 130 is removed from the elastic member 140 in an initial state in which no current is applied to the coil. It can be supported to be arranged in a second initial position different from the first initial position. In the up position, when a forward current is applied to the coil, the mover 130 may move from the second initial position to a direction closer to the macro position shown in FIG. 5. Here, the macro position may be a macro position.

As shown in FIG. 5, the distance D from the second initial position to the macro position may be longer than the distance E from the first initial position to the position contacting the base 110.

Although the embodiments according to the present invention have been described above, they are merely exemplary, and those skilled in the art will understand that various modifications and equivalent ranges of the embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be defined by the following claims.

Claims (20)

cover;
A mover disposed in the cover;
A coil disposed on the mover;
A magnet facing the coil and disposed between the coil and the cover;
A base disposed on one side of the mover; And
It includes an elastic member coupled to the mover,
The mover moves between the base and the cover along the optical axis,
When the mover is in a down posture disposed below the base, in the initial state in which no current is applied to the coil, the elastic member supports the mover to be disposed at a first initial position spaced apart from the base,
In the down position, when a reverse current is applied to the coil, the mover moves in a direction closer to the base from the first initial position,
When the mover is in an up position disposed above the base, the elastic member supports the mover to be disposed at a second initial position different from the first initial position in an initial state in which no current is applied to the coil,
In the up position, when a forward current is applied to the coil, the mover moves in a direction closer to the macro position from the second initial position,
The voice coil motor has a longer distance from the second initial position to the macro position than a distance from the first initial position to a position in contact with the base. According to claim 1,
The amount of the forward current for the mover to move from the second initial position to the macro position is greater than the amount of the reverse current for the mover to move from the first initial position to a position in contact with the base. . According to claim 1,
The voice coil motor is movable in the direction away from the base in the macro position. According to claim 1,
In the macro position, the mover is a voice coil motor spaced apart from the cover. According to claim 1,
In the up position, in the initial state in which no current is applied to the coil, the elastic member supports the mover so that the mover contacts the base. The method of claim 5,
When the optical axis is in a side posture arranged parallel to the ground, in the initial state in which no current is applied to the coil, the elastic member supports the mover so that the mover contacts the base. The method of claim 6,
In the up position, when the forward current of less than the reference current is applied to the coil, the mover does not move, and when the forward current of more than the reference current is applied to the coil, the voice coil motor moves. The method of claim 7,
A voice coil motor in which the start current at which the mover starts moving in the side posture is smaller than a start current at which the mover starts moving in the up pose. The method of claim 8,
A voice coil motor having a start current of 0 to 10 mA in the side posture. According to claim 1,
The base is formed in a plate shape with an opening through which light passes in the center,
The base is a voice coil motor that serves as a lower stopper of the mover. According to claim 1,
The cover is fixed to the base,
The cover is a voice coil motor that serves as an upper stopper of the mover. According to claim 1,
In the up position, the elastic member presses the mover so that an offset exists,
In the down position, the offset disappears due to deflection due to the weight of the mover. According to claim 1,
The elastic member is a voice coil motor including a first elastic member coupled to the upper portion of the mover, and a second elastic member coupled to the lower portion of the mover. Image sensor;
The voice coil motor of claim 6; And
A camera module comprising a lens coupled to the mover of the voice coil motor. The method of claim 14,
A posture detection sensor to determine posture of the up posture, the side posture, and the down posture and output posture data; And
A camera module further comprising an image signal processor (ISP) that generates a driving signal for driving the voice coil motor with the attitude data output from the attitude sensor. The method of claim 15,
Further comprising an auto-focus algorithm used in the form of an algorithm inside the image signal processor or embedded in a chip separate from the image signal processor,
The auto focus algorithm is a camera module that detects the focus value of the voice coil motor according to the distance to the subject and outputs a detection signal. The method of claim 15,
The posture detection sensor is a camera module including a gyro sensor that senses the direction of gravity. A mobile phone comprising the camera module of claim 14. cover;
A mover disposed in the cover;
A coil and a magnet disposed in the cover and moving the mover along an optical axis;
A base disposed on one side of the mover; And
It includes an elastic member coupled to the mover,
When the mover is in a down posture disposed below the base, in the initial state in which no current is applied to the coil, the mover is disposed in a first initial position spaced apart from the base,
When the mover is in an up position disposed above the base, in the initial state in which no current is applied to the coil, the mover is disposed in a second initial position different from the first initial position,
A voice coil motor having a distance between the second initial position and the macro position is longer than a distance between the first initial position and the position contacting the base. cover;
A mover disposed in the cover;
A coil disposed on the mover;
A magnet facing the coil and disposed between the coil and the cover;
A base disposed on one side of the mover; And
It includes an elastic member coupled to the mover,
The mover is a voice coil motor that moves between the base and the cover along the optical axis.

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