KR20070046368A - Camera module and manufacture method of camera module - Google Patents

Abstract

The present invention relates to a camera module for forming an assembly structure in a housing part and a manufacturing method thereof in order to have a wavefront generating mirror in which the wavefront is controlled by an electrical signal. The camera module according to the present invention refracts light to produce a subject image. A lens unit; A wavefront generating mirror for reflecting a subject image refracted on the lens unit and adjusting a wavefront power value of a reflecting surface according to an externally applied voltage to adjust a reflection angle on the subject; A cover glass for protecting the reflective surface of the wavefront generating mirror; An optical conversion element for converting the light signal on the subject reflected from the wavefront generating mirror into an electrical signal; And an open portion having the lens unit and the light conversion element fixed therein and having an assembly unit disposed in an area between the lens unit and the light conversion element, wherein the cover glass and the wavefront generating mirror are in turn. And an assembled housing part.

According to the present invention, it is possible to reduce the size of the conventional camera module to about 50% or less by providing a wavefront generating mirror, a lens unit and a light conversion element, and to compensate for the surface fragility of the wavefront generating mirror, as well as the manufacturing process. There is an effect that can maintain stable performance in terms of.

Description

Camera module and manufacture method of camera module}

1 is a view schematically showing the components of a camera module whose lens focus is adjusted by a conventional driving unit.

2 is a view schematically showing the components of a camera module according to an embodiment of the present invention.

Figure 3 is a side cross-sectional view showing the form after the camera module is assembled according to an embodiment of the present invention.

4 is a flowchart illustrating a manufacturing method of a camera module according to the present invention;

5 is a view showing a first process state of the camera module before the cover glass, the wavefront generating mirror and the light conversion element according to the present invention are assembled.

6 is a view showing a second process state of the camera module after the cover glass is assembled to the housing unit according to the present invention.

7 is a view showing a third process state of the camera module showing the form in which the wavefront generating mirror is assembled to the housing unit according to the present invention.

8 is a view showing a fourth process state of the camera module showing the form in which the light conversion element is assembled to the housing unit according to the present invention.

<Explanation of symbols for main parts of drawing>

100: camera module 110: lens unit

120: wavefront generating mirror 130: optical conversion element

140: circuit portion 142: CDS / AGC

144: image processing module 146: driver circuit

150: infrared cut filter 160: cover glass

170: housing portion 172: assembly portion

The present invention relates to a camera module, and more particularly, to a camera module and an assembly method for forming an assembly structure in a housing part to have a wavefront generating mirror whose wavefront is controlled by an electrical signal.

Currently, mobile communication terminals such as mobile phones, smartphones, PDAs (Personal Digital Assistants), DMB (Digital Multimedia Broadcasting) phones, laptops, and the like have a built-in zoom type camera module used in the existing DSC (Digital Still Camera) to capture images. And storage.

Such a camera module is used for not only a mobile communication terminal but also a monitoring device such as a rear sensing device of a vehicle, a toy, a public place, etc. The general structure is as follows.

1 is a view schematically showing the components of the camera module 10 whose lens focus is adjusted by a conventional driver.

According to FIG. 1, the conventional camera module 10 includes a driving unit 12, a lens unit 14, and a sensor 16. The driving unit 12 drives a transfer member by controlling a motor. The lens portion 14 is moved back and forth along the optical axis on the transfer member.

As the motor, a voice coil motor (VCM), a stepping motor, a piezo motor, etc. may be used. However, since the motor is installed, a large amount of mechanical space is required and power consumption required for driving the motor is large. There are disadvantages.

In general, the lens unit 14 includes a focus unit for focusing a subject, a shift unit for changing a magnification of an image, a compensation unit for compensating a store according to a shift, and the focus unit, a shift unit, Each of the compensators is provided with at least one lens.

In addition, since the lens shape of the focus unit is a fixed (RIGID) type, magnification adjustment may be performed by the transfer member and the motor according to the distance of the intermediate part, and the compensator compensates for the positional change of the upper surface, thereby maintaining a fixed image. Will be.

In addition, the sensor 16 drives the lens unit 14 to receive a focus-formed light signal and to convert it into an electrical signal.

However, according to the structure of the conventional camera module as described above, the mechanical volume increases as described above, the structural weakness of the motor itself (for example, when the leaf spring provided in the motor is detached when the mobile communication terminal is exposed to impact). Often occurs), the reliability of operation is lowered, the structural durability due to the mechanical coupling of the motor, the transfer member and the lens portion, and the like, and the battery capacity is large because the power consumption is increased. The problem exists.

Accordingly, the present invention minimizes the size of the camera module, improves reliability and durability, and can be driven with a small power by replacing the conventional drive motor and the transfer member with a wavefront generating mirror having a structure that protects the surface. Its purpose is to provide a module.

In addition, the present invention, when assembling the housing portion of the camera module, the optical change element and the wavefront generating mirror implemented on the substrate, it is possible to effectively mount the cover glass to protect the surface of the wavefront generating mirror to simplify the assembly process of each component It is another object of the present invention to provide a method for manufacturing a camera module which can minimize the contact of the wavefront generating mirror.

In order to achieve the above object, the camera module according to the present invention comprises a lens unit for refracting light to form a subject image; A wavefront generating mirror for reflecting a subject image refracted on the lens unit and adjusting a wavefront power value of a reflecting surface according to an externally applied voltage to adjust a reflection angle on the subject; A cover glass for protecting the reflective surface of the wavefront generating mirror; An optical conversion element for converting the light signal on the subject reflected from the wavefront generating mirror into an electrical signal; And an open portion having the lens unit and the light conversion element fixed therein and having an assembly unit disposed in an area between the lens unit and the light conversion element, wherein the cover glass and the wavefront generating mirror are in turn. And an assembled housing part.

In addition, the camera module according to the present invention receives the electrical signal from the optical conversion element calculates the accuracy of the focus of the subject image, and a circuit unit for applying a control voltage to the wavefront generating mirror according to the calculated accuracy of the focus It is characterized in that the further provided.

In addition, the wavefront generating mirror of the camera module according to the invention is characterized in that implemented by the MEMS (Micro-Electro-Mechanical System) technology.

In order to achieve the above object, the camera module manufacturing method according to the present invention comprises the steps of forming a housing; Forming a lens part which refracts light to form an object image on the housing part; Forming a wavefront generating mirror in an area of the housing part in contact with a path of light transmitted from the lens unit to adjust a wavefront power value of a reflective surface to adjust a reflection angle on the subject; And a photoconversion device for converting a light signal into an electrical signal in an area of the housing part in contact with the path of light reflected from the wavefront generating mirror.

In the manufacturing method of the camera module according to the present invention, the forming of the lens unit may further include forming an infrared cut filter into the housing unit before or after the lens unit is formed. do.

In addition, the step of forming the wavefront generating mirror in the camera module manufacturing method according to the present invention, after the cover glass is formed, characterized in that the wavefront generating mirror is formed so that the reflection surface is adjacent to the cover glass.

Hereinafter, a camera module according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a view schematically showing the components of the camera module 100 according to an embodiment of the present invention.

Referring to FIG. 2, the camera module 100 according to the embodiment of the present invention includes a lens unit 110, a wavefront generating mirror 120, a light conversion element 130, a circuit unit 140, and an infrared ray blocking filter (IR filter). And 150.

First, the lens unit 110 refracts light to form an object image, and the wavefront generating mirror 120 reflects light passing through the lens unit 110.

The light reflected through the lens unit 110 is incident on the light conversion element 130 and converted into an electrical signal, and is processed as an image signal by the image processing on the circuit unit 140, or the circuit unit is determined to be out of focus. 140 controls the voltage to supply the wavefront generating mirror 120.

The wavefront generating mirror 120 reflects the subject image refracted by the lens unit 110, and adjusts the reflection angle of the subject by adjusting the wavefront power value of the reflecting surface according to the control voltage transmitted from the circuit unit 140. Therefore, the light passing through the lens unit 110 is reflected on the wavefront generating mirror 120, the reflection angle is adjusted to be focused.

In addition, the wavefront generating mirror 120 is provided with a surface protection cap, to prevent the reflective surface from being damaged by contact, external impact, wind, dust, etc. during the assembly process or use.

According to the embodiments of the present invention, the position of the wavefront generating mirror 120 and the lens unit 110 can be designed in various forms. In the embodiment of the present invention, the wavefront generating mirror 120 of the lens unit 110 Located in the rear.

Through this structure, the camera module according to the present invention does not move the lens back and forth through mechanical control such as a conventional motor and a transfer member, but rather reflects the reflected wavefront of the wavefront generating mirror 120 through an electrical signal. The focus is on the controlling structure.

Figure 3 is a side cross-sectional view showing the form after the camera module according to the embodiment of the present invention is assembled.

Referring to FIG. 3, first, the lens unit 110, the wavefront generating mirror 120, and the light conversion element 130 are positioned in three regions a1, a2, and a3 of the housing unit a, respectively. The first area a1 where the 110 is located and the second area a2 where the wavefront generating mirror 120 are located are formed to be adjacent to each other and the third area where the light change element 130 is positioned below the first area a1. a3) is formed.

In addition, the infrared cut filter 150 is provided above the light conversion element 130, the infrared cut filter 150 has a function to block the radiant heat emitted from the external light is not transmitted to the light conversion element 130. do.

That is, the infrared cut filter 150 has a structure that transmits visible light and reflects infrared light to flow out.

The lens unit 110 is preferably made of a plurality of lenses each having a different shape, and according to the present invention, there is no physically driven portion is fixed inside the housing including the lens barrel.

For example, the lens unit 110 may include three lenses of the first lens 112, the second lens 114, and the third lens 116, wherein the first lens 112 has a negative refractive index. By having a concave surface toward the subject side, a wide viewing angle is secured from the subject side, and a sufficient focal length is secured to collect external light in one place.

In this case, an aperture stop (not shown) may be provided next to the first lens 112 to reduce flare / ghost generation, and the second lens 114 is positioned behind the first lens 112.

The second lens 114 has a positive refractive index and extends light passing through the first lens 112, and has a meniscus shape convex toward the subject side in order to extend the light.

The third lens 116 forms a spherical surface on both sides to prevent the light transmitted through the second lens 114 from being biased inwards, and transmits the image of the subject to the wavefront generating mirror 120.

The lenses provided in the lens unit 110 have a spherical or aspherical surface shape, the focal length of each lens, the optical length (length of the entire lens unit), the radius of curvature for the lens surface / aperture, the center interval, the refractive index, By considering the light scattering degree and the like, distortion aberration, spherical aberration, and the like are corrected and the position thereof is determined.

On the other hand, the wavefront generating mirror 120 is located behind the lens unit 110 to reflect the subject image transmitted from the lens unit 110, the reflected object image forms a structure that is incident to the light conversion element 130. .

That is, the wavefront generating mirror 120 reflects the subject image so that the path of the light penetrating through the lens unit 110 and the path of the light incident on the light conversion element 130 are perpendicular to each other. ) Forms an angle of 45 degrees with the optical axis of the lens unit 110, and also forms an angle of 45 degrees with the optical axis incident to the light conversion element 130.

The wavefront generating mirror 120 may be implemented by MEMS (Micro-Electro-Mechanical System) technology, and as described above, zooms by generating an arbitrary wavefront according to the magnitude of the voltage applied from the circuit unit 140. ) Or as a focusing device.

The wavefront generating mirror 120 implemented by the MEMS technology arranges the micro-fragmented mirrors, which are minutely divided, on the surface, and the power values of these fragmentary mirrors (wavefronts) are adjusted to adjust the reflection angle of light.

Here, MEMS technology refers to a system in which microstructures (millions of meters) and electronic circuits are integrated and combined, and have a structure that precisely processes extremely fine reflective piece structures and couples electronic circuits. .

As described above, according to the wavefront generating mirror 120 using the MEMS technology, the size and power consumption of the camera module of the conventional mechanical structure can be greatly reduced, and the function of controlling the focus can be more precisely implemented.

However, since the surface of the wavefront generating mirror 120 is very weak and sensitive unlike general glass, the wavefront sensitivity may be lowered due to, for example, fingerprints, breathing, or wind.

Therefore, if the wavefront generating mirror 120 is in contact during the assembly process or dust is injected into the housing 170 during use, there is a risk that the function is reduced. In particular, the biggest problem in the process of manufacturing the camera module according to the present invention can be seen as the surface vulnerability of the wavefront generating mirror 120.

For this reason, the wavefront generating mirror 120 is provided with a cover glass 160, the configuration and the manufacturing method associated with it will be described with reference to Figs.

4 is a flowchart illustrating a manufacturing method of a camera module according to the present invention, and FIG. 5 is a camera module before the cover glass 160, the wavefront generating mirror 120, and the light conversion element 130 are assembled according to the present invention. 1 is a diagram showing a first process state.

First, the housing unit 170 is formed. The housing unit 170 includes the lens unit 110, the cover glass 160, the wavefront generating mirror 120, the IR filter 150, and the light conversion element 130. Assembly structures are formed to be assembled (S100).

In particular, an assembly unit 172 is formed in the second area a2 of the housing unit 170 so that the cover glass 160 and the wavefront generating mirror 120 may be assembled in sequence. ) May be formed of various types of structures, in the embodiment of the present invention is formed in the form of the locking projection (172a) and the locking groove (172b).

The locking protrusion 172a is a structure in which the cover glass 160 is assembled by the inner side of the housing portion 170 and the second area a2, and the locking groove 172b is also a plurality of the locking protrusion 172a. 172a) is formed outside the structure that the wavefront generating mirror 120 is assembled.

Referring to FIG. 5, when the housing unit 170 is formed, the lens unit 110 and the IR filter 150 are assembled, and the light conversion element 130 is inserted under the IR filter 150 (S200). .

FIG. 6 is a view illustrating a second process state of the camera module after the cover glass 160 is assembled to the housing unit 170 according to the present invention.

Subsequently, as shown in FIG. 6, in the state where the housing unit 170 is seated downward with the third region a3 into which the light conversion element 130 is inserted, the locking protrusions of the housing unit 170 ( The cover glass 160 is inserted into and fixed to the 172a (S300).

FIG. 7 is a view illustrating a third process state of the camera module, in which the wavefront generating mirror 120 is assembled to the housing unit 170 according to the present invention.

After the cover class 160 is assembled, as shown in FIG. 7, the wavefront generating mirror 120 is assembled to the housing unit 170 (S400), and the substrate embodied in the wavefront generating mirror 120. In this seated state, the housing unit 170 is moved in an inverted shape to be coupled to each other.

The wavefront generating mirror 120 is fixed to the locking groove 172b formed in the second area a2 of the housing part 170.

FIG. 8 is a view illustrating a fourth process state of the camera module, in which the light conversion element 130 is assembled to the housing unit 170 according to the present invention.

When the cover glass 160 and the wavefront generating mirror 120 are assembled, the photoconversion device 130 is assembled at an original position of the third region a3 of the housing unit 170 (S500). .

At this time, the housing unit 170 is assembled from the upper side in the state in which the substrate on which the light conversion element 130 is implemented is seated.

The light conversion element 130 is interpolated and fixed to the third region a3 of the housing unit 170.

In this case, the light conversion element 130, the wavefront generating mirror 120, the cover glass 160 may be coupled to the housing 170 using a UV (ultraviolet) curing paste.

2, the photoconversion device 130 may be formed of a component such as a charge coupled device (CCD), and the light signal transmitted from the refractive mirror 120 may be an electrical signal. To.

The circuit unit 140 includes a CDS / AGC (Correlated Double Sampling Hold & Auto Gain Control) 142, an image processing module 144, and a driver circuit 146.

The CDS / AGC 142 extracts only pure signal components by removing noise components of the electrical signal output from the photoconversion device 130, and outputs an optimal image signal by compensating for gains of signal components lost in the extraction process. Let's do it.

In addition, the image processing module 144 analyzes the electric signal to examine pixel components forming one image and determines whether the pixel areas are larger than a predetermined set value.

The driver circuit 146 receives the determination information of the image processing module 144 and generates a control voltage so that the wavefront generating mirror 120 adjusts the reflection angle to form an accurate focus.

The driver circuit 146 applies the generated voltage to the wavefront generating mirror 120.

In this case, the driver circuit 146 includes matching information to generate a control voltage corresponding to the determination information.

The present invention has been described above with reference to the preferred embodiments, which are merely examples and are not intended to limit the present invention, and those skilled in the art to which the present invention pertains do not depart from the essential characteristics of the present invention. It will be appreciated that various modifications and applications are not possible that are not illustrated above. For example, each component specifically shown in the embodiment of the present invention can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

According to the camera module according to the present invention, by providing a wavefront generating mirror, a lens unit, a light conversion element can reduce the size of the conventional camera module to about 50% or less, and manufactured to compensate for the surface vulnerability of the wavefront generating mirror It is effective to maintain stable performance not only in the process but also in terms of use.

In addition, according to the present invention, since the amount of power consumed to drive the lens unit can be greatly reduced, there is an effect that a device equipped with a camera module can be used for a long time even with a relatively small battery capacity.

In addition, according to the present invention, it is possible to improve the operational reliability and durability of the camera module by eliminating the structural weakness of the motor itself and the coupling structure between the mechanisms, and the effect of being able to form the focus more quickly and accurately than in the prior art. have.

Claims (10)

A lens unit refracting light to form an object image; A wavefront generating mirror for reflecting a subject image refracted on the lens unit and adjusting a wavefront power value of a reflecting surface according to an externally applied voltage to adjust a reflection angle on the subject; A cover glass for protecting the reflective surface of the wavefront generating mirror; An optical conversion element for converting the light signal on the subject reflected from the wavefront generating mirror into an electrical signal; And The lens unit and the light conversion element are fixed inside, and an opening having an assembly unit is formed in a region between the lens unit and the light conversion element, and the cover glass and the wavefront generating mirror are sequentially assembled to the assembly unit. Camera module comprising a housing portion. The method of claim 1, wherein the assembly portion And a first catching portion to which the cover glass is assembled and a second catching portion to which the wavefront generating mirror is assembled. The method of claim 1, wherein the opening portion The camera module, characterized in that the path of the light passing through the lens portion and the path of the light incident on the light conversion element is formed on the surface of the housing portion perpendicular to the. The method of claim 1, The camera further comprises a circuit unit for receiving the electrical signal from the optical conversion element calculates the accuracy of the focus of the subject image, and applies a control voltage to the wavefront generating mirror according to the calculated accuracy of the focus. module. The method of claim 1, wherein the wavefront generating mirror Camera module, characterized in that implemented by MEMS (Micro-Electro-Mechanical System) technology. Forming a housing part; Forming a lens part which refracts light to form an object image on the housing part; Forming a wavefront generating mirror in an area of the housing part in contact with a path of light transmitted from the lens unit to adjust a wavefront power value of a reflective surface to adjust a reflection angle on the subject; And And converting a light signal into an electrical signal in an area of the housing part in contact with the path of light reflected from the wavefront generating mirror. The method of claim 6, wherein the lens unit is formed in the housing unit. And forming an infrared cut filter into the housing part before or after the lens part is formed. The method of claim 6, wherein the wavefront generating mirror is formed And after the cover glass is formed, the wavefront generating mirror is formed such that the reflection surface is adjacent to the cover glass. The method of claim 6, wherein the wavefront generating mirror is formed Camera housing manufacturing method characterized in that the step of assembling the housing portion is moved on the wavefront generation mirror implemented substrate. The method of claim 6, wherein forming the photoconversion device is The camera module manufacturing method, characterized in that the housing is moved and assembled on the substrate on which the light conversion element is implemented.

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