WO2016133235A1

WO2016133235A1 - Camera module

Info

Publication number: WO2016133235A1
Application number: PCT/KR2015/002000
Authority: WO
Inventors: 이창환
Original assignee: 엘지전자 주식회사
Priority date: 2015-02-17
Filing date: 2015-03-02
Publication date: 2016-08-25
Also published as: KR20160101576A

Abstract

The present invention provides a camera module for imaging a subject, comprising: a first moving lens group which can move along an optical axis direction; a second moving lens group which can move relative to the first lens group along the optical axis direction in order to enlarge or reduce an image; an image sensor in which light having passed through the second moving lens group is focused and which can be deformed with reference to the center thereof; and a control unit for changing the curvature of the image sensor on the basis of movements of the first and second moving lens groups.

Description

Camera module

The present invention relates to a camera module capable of optical zoom.

The camera implementing the zoom function is a straight inner zoom camera including a driver and a focusing unit for zooming in a straight barrel, and a front protrusion for protruding the lens to the front when zooming. The camera may be classified into a banding compact zoom type camera in which a length of the camera module is reduced by changing an intermediate optical path by inserting a camera, a mirror, or a prism.

Or, there is a disadvantage in that the image quality for driving the zoom is reduced in order to apply a zoom camera to thin mobile products, but a digital zoom camera that does not require a separate component (digital zoom camera) Two fixed with two different focal lengths There is a dual zoom camera that is formed by arranging the focus lens in parallel.

However, since the zoom lens complicates the configuration of the lens compared to the fixed focus lens and the number of lenses increases and a driving motor for moving the lens must be included, the volume increases. Since the interpolation of the zoom ratio between two lenses is limited, it is difficult to apply high magnification.

Accordingly, the technical problem of the present invention is to provide a compact zoom camera module.

In order to achieve the object of the present invention, the camera module of the present invention for photographing a subject according to an embodiment is a first moving lens group made to be movable along the optical axis direction, to enlarge or reduce the image A second moving lens group configured to be relatively movable with the first lens group along the optical axis direction, the light passing through the second moving lens group is formed, and the image sensor is configured to be deformable with respect to the center And a controller configured to change the curvature of the image sensor based on the movement of the first and second moving lens groups.

As an example related to the present invention, the image sensor is deformed so that one surface facing the second moving lens group forms a concave shape.

As an example related to the present invention, the controller may control the image sensor to have a larger curvature as the zoom factor is higher.

As an example related to the present disclosure, the controller may control at least one of the first and second moving lens groups to move along the optical axis direction based on the zoom ratio.

As an example related to the present invention, the controller moves the image sensor along the optical axis direction based on the zoom ratio.

As an example related to the present disclosure, the control unit may move the image sensor and the first moving lens group closer to each other as the zoom magnification increases, and control the second moving lens group to be fixed.

As an example related to the present invention, the image sensor may be made of a material whose shape is deformed based on an electrical signal.

As an example related to the present disclosure, the controller may deform the image sensor to have any one of a plurality of preset curvatures corresponding to a plurality of preset reference magnifications.

As an example related to the present invention, the control unit acquires a first image of the subject at a first reference magnification smaller than the target magnification, based on a control command for photographing the subject at a target magnification, wherein the first magnification is greater than the target magnification. Acquiring a second image at a second reference magnification, upscaling the first image to form a third image, downscaling the second image to form a fourth image, and the third and fourth A control method may be performed including synthesizing an image.

As an example related to the present invention, the camera module may be installed on the base barrel, the base barrel to be movable along the optical axis direction, the first barrel housing the first moving lens group, and the optical axis direction to the base barrel. And a second barrel configured to be movable along the second barrel to accommodate the second lens group, and the controller may control to change the curvature based on the movement of the first and second barrels.

According to the present invention, it is possible to prevent a filed curvature, which is a light aberration generated due to a different position where the image is formed in the center and the peripheral portion of the image sensor by different refractive characteristics of the central and peripheral rays of the plurality of lenses. . Therefore, it is possible to output an image with a constant resolution of the central portion and the periphery.

In addition, by the curvature of the image sensor, the angle (CRA, Chief Ray Angle) of the light incident to the peripheral portion is reduced to improve the brightness of the image. Additionally arranged to correct the ray aberration

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

FIG. 2 is a conceptual diagram illustrating an optical arrangement of an optical system of the camera module of FIG. 1. FIG.

3A to 3C are conceptual views for explaining a modification of the image sensor according to the present embodiment.

4A to 4C are conceptual views illustrating a method of controlling a camera module according to an embodiment.

5 is a block diagram illustrating components of a camera module according to another exemplary embodiment.

6 is a conceptual view illustrating a control method of the camera module of FIG. 5. 7A and 7B are conceptual views illustrating a control method of a camera module in which a zoom function is implemented discontinuously according to an exemplary embodiment.

8A and 8B are conceptual views illustrating a camera module accommodated in a barrel type driving device.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings, and the same or similar components are denoted by the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "unit" for components used in the following description are given or used in consideration of ease of specification, and do not have distinct meanings or roles from each other. In addition, in describing the embodiments disclosed herein, when it is determined that the detailed description of the related known technology may obscure the gist of the embodiments disclosed herein, the detailed description thereof will be omitted. In addition, the accompanying drawings are intended to facilitate understanding of the embodiments disclosed herein, but are not limited to the technical spirit disclosed herein by the accompanying drawings, all changes included in the spirit and scope of the present invention. It should be understood to include equivalents and substitutes.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

Singular expressions include plural expressions unless the context clearly indicates otherwise.

In this application, the terms "comprises" or "having" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

1 is a block diagram illustrating components of a camera module according to an exemplary embodiment of the present invention, and FIG. 2 is a conceptual diagram illustrating an optical arrangement of an optical system of the camera module of FIG. 1.

The camera module according to the exemplary embodiment of the present invention includes a first fixed lens group 110 having negative refractive power sequentially arranged, a first moving lens group 120 having positive refractive power, and a second fixed lens group having positive refractive power. 130, a second moving lens group 130, and an image sensor 150. The first and second moving

lens groups

120 and 140 are formed to move along an optical axis extending in the first direction D1. That is, the first moving lens group 120 is connected to the first driving unit 121, and the second moving lens group 140 is connected to the second driving unit 142.

The first fixed lens group 110 includes a first lens L1, a second lens L2, and a prism disposed therebetween. In detail, the first fixed lens group 110 includes a first lens L1 of a meniscus-shaped single lens having negative refractive power, and a prism P formed to convert an optical path to about 90 degrees. The second lens L1 may be formed of a single lens having refractive power.

The first moving lens group 120 includes third to fifth lenses L3, L4, and L5. The second fixed lens group 130 includes a sixth lens L6, and the second moving lens group 140 includes seventh to ninth lenses L7, L8, and L9. Light passes through the first fixed lens group 110, the first moving lens group 120, the second fixed lens group 130, and the second moving lens group 140 to reach the image sensor 150. .

At least one of the lenses of the second moving lens group 140 may be formed of an aspherical lens. In this case, negative distortion aberration can be corrected at the wide-angle end.

An aperture IRIS is formed between the first moving lens group 120 and the second moving lens group 130. Although not illustrated in detail, a low pass filter (LP), an infrared cut filter, and a cover glass of the CCD may be disposed between the image sensor 150 and the second moving lens group 140. CG) can be deployed.

The controller 101 performs zooming by moving the first and second moving

lens groups

120 and 140. When changing from the short focal length end (wide end) to the long focal length end (telephoto end), the first moving lens group 120 moves from the area where the object is located to the image plane side. The controller 101 adjusts focus by moving the second moving lens group 140.

The first and second moving

lens groups

120 and 140 may move in association with each other by the first and

second driving units

121 and 141, but the present invention is not limited thereto and the moving directions may be the same or may be reversed. have.

Light passing through the first and second moving

lens groups

120 and 140 and the first and second

fixed lens groups

110 and 130 reaches the image sensor 150, whereby the focused image elements are focused. It is converted and output as an image. remind

In the camera module according to the present embodiment, the shape of the image sensor 150 is modified to perform a zooming function. Hereinafter, a feature of changing the shape of the image sensor 150 will be described.

3A to 3C are conceptual views for explaining a modification of the image sensor according to the present embodiment. 3A shows the shape of the image sensor at the telephoto end, and FIG. 3C shows the shape of the image sensor at the wide angle end. When the image sensor 150 has a curvature, the image sensor 150 is disposed in the optical system so that the light is incident on the concave area of the image sensor 150.

The image sensor 150 according to the present exemplary embodiment may be modified to form a curved surface based on the center O. FIG. That is, the image sensor 150 is deformed to have a predetermined curvature based on the center O. For example, the image sensor 150 may be formed of a shape deformation material whose shape is deformed based on an electrical signal.

The controller 101 may control the degree of deformation of the image sensor 150 based on the zoom ratio of the zooming. The image sensor 150 is deformed to have a large curvature at a high zoom factor, and is deformed to have a small curvature at a low zoom factor. In the default state, the image sensor 150 may maintain a flat flat state as illustrated in FIG. 3C.

3A to 3C, the image sensor 150 may be fixed by the frame 151 at the edge. Accordingly, the planar area of the image sensor 150 perpendicular to the moving direction of the light that can reach the light may be maintained to be substantially the same. However, the structure in which the image sensor 150 is implemented is not limited thereto. For example, the planar area of the image sensor 150 perpendicular to the moving direction of the light due to the deformation of the image sensor 150 may be formed to be narrower as the bending of the image sensor 150 becomes larger.

Although not specifically illustrated in the drawings, the image sensor 150 may be made of an elastic material that is deformable by physical pressing. For example, a pressing member (not shown) disposed to be adjacent to the image sensor 150 and formed to have a predetermined curvature may apply an external force to the image sensor 150 to provide an image of the image sensor 150. It can be controlled to deform the curvature. The pressing member (not shown) may be implemented to interlock with the first and

second driving units

121 and 141.

The image sensor 150 according to an embodiment may be formed to have a predetermined discontinuous curvature. For example, in consideration of the characteristics of the optical system constituting the camera module, it may be set to be deformed to the first to third curvature. Alternatively, the image sensor 150 may be set to continuously modify the curvature.

Accordingly, it is possible to prevent a filed curvature, which is a light aberration generated due to a different position where the image is formed at the central portion and the peripheral portion of the image sensor due to different refractive characteristics of the central and peripheral rays of the plurality of lenses. Therefore, it is possible to output an image with a constant resolution of the central portion and the periphery.

In addition, by the curvature of the image sensor, the angle (CRA, Chief Ray Angle) of the light incident to the peripheral portion is reduced to improve the brightness of the image. The number of correction lenses additionally arranged to correct the light aberration can be reduced, so that the camera module can be miniaturized.

Hereinafter, a control method of deforming an image sensor together with a zooming function and a focus function will be described.

4A to 4C are conceptual views illustrating a method of controlling a camera module, according to an exemplary embodiment.

2 and 4A, when the zoom magnification is increased, that is, when the zoom magnification is changed from the wide-angle end to the telephoto end, the first moving lens group 120 which is the zoom driving group is gradually adjacent to the image sensor 150. Moves in the first direction D1. In conjunction with this, the second moving lens group 140 moves in the first direction D1, and when the second zoom lens group is greater than or equal to a preset zoom ratio, the second moving lens group 140 moves in a direction opposite to the first direction D1. In the present embodiment, the control unit 101 deforms the image sensor 150 so that the curvature gradually increases when the zoom magnification increases.

2 and 4B, the first and second moving

lens groups

120 and 140 move in substantially the same direction based on the change in the zoom ratio. However, the speed at which the first and second moving

lens groups

120 and 140 are moved may be implemented differently, and the first and

second driving units

121 and 141 may be formed of the same motor.

In the present embodiment, the image sensor 150 does not move according to the change of the zoom factor, and the controller 101 deforms the curvature of the image sensor 150 to gradually increase as the zoom factor increases.

2 and 4C, the first moving lens group 120 moves based on the change of the zoom ratio. When the zoom factor is increased, the first moving lens group 120 moves in a direction adjacent to the image sensor 150. The second moving lens group 140 is fixed even if the zoom ratio is changed. The image sensor 150 is modified to increase curvature when the zoom magnification is increased. According to the present embodiment, the second moving lens group 140 for adjusting focus is kept fixed, and the curvatures of the first moving lens group 120 and the image sensor 150 are modified. By controlling the image formed on the image sensor 150 can be controlled.

FIG. 5 is a block diagram illustrating components of a camera module according to another exemplary embodiment. FIG. 6 is a conceptual diagram illustrating a control method of the camera module of FIG. 5.

The camera module according to the present embodiment moves the first and second

fixed lens groups

110 and 130, the first and second moving

lens groups

120 and 140, the image sensor 150, and the image sensor 150. The third driver 151 to be included. The camera module other than the third driving unit 151 is substantially the same as the components of the camera module of FIG. 2. Therefore, the same reference numerals are assigned to the same and similar components, and duplicate descriptions are omitted.

Referring to FIG. 6, as the zoom magnification increases, the first moving lens group 120 moves in the first direction D1 closer to the image sensor 150. In this case, the second moving lens group 140 does not move but is fixed. In the camera module according to the present embodiment, the second driving unit 141 may be omitted.

On the other hand, the image sensor 150 is controlled such that the curvature increases as the zoom magnification increases. In addition, the controller 101 controls the third driver 151 to move the image sensor 150 according to the change of the zoom ratio.

For example, the image sensor 150 moves in a direction closer to the second moving lens group 140 as the zoom magnification increases, and when the preset magnification is reached, the second moving lens group 140 again. Can be moved away from (a).

Alternatively, the controller 101 may control the third driver 151 to move the image sensor 150 to be closer to the second moving lens group 140 as the zoom magnification increases. In this case, the first and

third driving units

121 and 151 may be interlocked, and the first and

third driving units

121 and 151 may be implemented as one driving motor.

According to the present embodiment, a component for moving the second moving lens group 140 is unnecessary, and the image sensor can be moved to accurately enter a larger amount of light.

7A and 7B are conceptual views illustrating a control method of a camera module in which a zoom function is implemented discontinuously according to an exemplary embodiment.

Referring to FIG. 7A, the controller 101 deforms the image sensor 150 to have a preset curvature based on the preset zoom ratio. Although not illustrated in detail, the controller 101 may control the first and second drivers 121 and 141 (or the first and third drivers) to form a preset zoom ratio according to a user's control command. 121, 151).

However, the second driving unit 141 of the camera module according to the present embodiment is controlled to compensate the distance of the subject by continuously moving the second moving lens group 140.

For example, when it is set to be driven with reference magnifications set to 1, 3, and 5 magnifications, the image sensor is flat when the magnification is 1 times, and when the magnification is 3 times, the image sensor 150 The image sensor 150 is deformed to have a first curvature, and the image sensor 150 is deformed to have a second curvature greater than the first curvature when the zoom factor is 5 times. Hereinafter, a control method when a control command for capturing an image at a target magnification other than the reference magnification is applied will be described.

The controller 101 obtains a first image of the subject at a first reference magnification closest to the target zoom magnification among the preset reference magnifications and smaller than the target zoom magnification (S10). For example, when the target zoom magnification is 4 ×, the subject is photographed at the third magnification.

The controller acquires a second image of the subject at a second reference magnification closest to a target zoom magnification among the reference magnifications and larger than a target zoom magnification (S11). For example, the subject is photographed at the 5 magnifications.

The controller generates a third image that upscales the first image (S12), and generates a fourth image that downscales the second image (S13).

The controller synthesizes the third and fourth images to form an image photographed at the four magnifications (S14).

According to the present embodiment, in the case of a camera module configured to have a discontinuous zoom function, two images may be synthesized to form an image photographed at a magnification between a reference zoom ratio.

On the other hand, the controller may adjust the aperture at the first and second reference magnification to obtain a bright image and a dark image to improve the HDR image.

8A and 8B are conceptual views illustrating a camera module accommodated in a barrel type driving device. 8A is an exploded perspective view illustrating an optical system driving apparatus of a camera module according to an embodiment, and FIG. 8B is a cross-sectional view illustrating the optical system driving apparatus.

8A and 8B, the driving device includes a base 30, a main barrel 41 fixed to the base 30, a first barrel 43 surrounding the first moving lens group 120, The second barrel 45 surrounding the second fixed lens group 130, first driving means 50 for driving the first and

second barrels

43 and 45, and the first fixed lens group 110. It includes a third barrel 61 for enclosing, the second driving means 70 for driving the third barrel 61. In addition, the driving device is installed in the fourth barrel 81 and the fourth barrel 81 coupled to the rear of the main barrel 41 and the entire group of lens groups 140a of the second moving lens group 140. The sixth barrel 85 formed to surround the rear lens group 140b and the rear lens group group 140b formed to surround the fifth barrel 83 and the second moving lens group 140 are formed. And third driving means 90 for adjusting the focal length.

The first barrel 43 is linearly moved along the first direction D1 by the first driving means 50 in the main barrel 41. The cam barrel 55 is rotated by the first driving means 50. As the cam barrel 55 rotates, the first barrel 43 is linearly moved in accordance with the position change of the first cam groove 55a. The first barrel 43 is formed with a first guide roller 44 fitted into the first cam groove 55a.

In addition, the second barrel by the second cam groove 55b formed in the cam barrel 55 and the second guide roller 46 formed in the second barrel 45 and fitted into the second cam groove 55b. 45 moves linearly.

The second driving means (70) is for driving the third barrel (61) relative to the main barrel (41), the second drive source 71 and the gear formed on the outer periphery of the third barrel (61) The member 75 is comprised.

The gear member 75 is rotated in engagement with the second drive gear 73 provided on the rotation shaft 71a of the second drive source 71, and the third barrel 61 is rotated by the rotation of the gear member 75. Rotate At this time, since the third barrel 61 is screwed with respect to the main barrel 41, the third barrel 61 is moved in parallel with the optical axis while rotating. That is, as the third barrel 61 moves in accordance with the normal and reverse rotation of the second driving source 71, the first moving lens group 120 installed in the third barrel 61 is operated to focus.

The cam member 91 has a circular cam structure, and an end portion 91a fitted to the operation piece 93 is eccentrically positioned with respect to the rotation center of the cam member 91. The support piece 95 is screwed to the outer circumference of the fourth barrel 91 by a screw to prevent the cam member 91 from being separated.

In addition, the control unit detects the driving of the first to third driving means (50, 70, 90) to control the deformation of the image sensor 150. Although not shown in detail in the drawings, when the barrel is moved relative to the external force, the sensing unit for detecting the relative movement of the barrel may be further included. In this case, the controller may control the shape of the image sensor by the detector.

In addition, the image sensor is formed to move relative to the base 30 and has an additional barrel for accommodating the image sensor 150, so that the image sensor may move relative to the lenses.

The foregoing detailed description should not be construed as limiting in all respects, but should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

Embodiments of the present invention provide a camera module including an image sensor and provide a structure in which a bending sensor whose shape is deformed injects more light transmitted to a peripheral part, and thus may be applied to various industrial fields.

Claims

In the camera module for imaging the subject, The camera module,

A first moving lens group configured to be movable along the optical axis direction;

A second moving lens group configured to be movable relative to the first lens group along the optical axis direction to enlarge or reduce the image;

An image sensor formed to form light passing through the second moving lens group and being deformable with respect to a center; And

And a controller configured to change the curvature of the image sensor based on the movement of the first and second moving lens groups.
The method of claim 1,

The image sensor is a camera module, characterized in that deformed to form a concave shape of one surface facing the second moving lens group.
The method of claim 2,

The control unit is a camera module, characterized in that for controlling the image sensor to have a larger curvature as the zoom ratio is higher.
The method of claim 3,

And the control unit moves at least one of the first and second moving lens groups along the optical axis direction based on the zoom ratio.
The method of claim 4, wherein

And the control unit moves the image sensor along the optical axis direction based on the zoom ratio.
The method of claim 5,

The controller moves the image sensor and the first moving lens group closer to each other as the zoom ratio increases, and fixes the second moving lens group.
The method of claim 1,

The image sensor is a camera module, characterized in that made of a material that is deformed based on the electrical signal.
The method of claim 1,

And the control unit deforms the image sensor to have any one of a plurality of preset curvatures corresponding to a plurality of preset reference magnifications.
The method of claim 8, wherein the controller is further configured to control the photographing of the subject at a target magnification.

Acquiring a first image of a subject at a first reference magnification smaller than the target magnification;

Acquiring a second image at a second reference magnification greater than the target magnification;

Upscaling the first image to form a third image;

Downscaling the second image to form a fourth image; And

And executing a control method including synthesizing the third and fourth images.
The method of claim 1,

Base barrel;

A first barrel mounted to the base barrel to move along the optical axis direction and accommodating the first lens group;

A second barrel installed on the base barrel to be movable along the optical axis direction and accommodating the second lens group;

And the controller changes the curvature based on the movement of the first and second barrels.