KR100812008B1 - Camera module and manufacture method thereof - Google Patents

Abstract

The camera module manufacturing method according to the present invention relates to a camera module including a housing part, a lens part, a wavefront generating mirror, and a photoconversion device, wherein the light conversion device and the wavefront generating mirror are mounted on a printed circuit board in an array state. Becoming; Assembling a surface protection cap to the wavefront generating mirror; Coupling a printed circuit board area on which the photoconversion device is mounted, to the housing part; Separating the printed circuit board area on which the wavefront generating mirror is mounted from the substrate array; And assembling the printed circuit board area of the separated wavefront generating mirror to the 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

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 assembling the wavefront generating mirror and the light conversion element according to the present invention;

6 is a view showing a second process state of the camera module before assembling the wavefront generating mirror and the light conversion element 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: surface protective cap

162: cover glass 164: cap adapter

170: printed circuit board 172: light conversion element-side rigid printed circuit board

174: wavefront generating mirror-side rigid printed circuit board

The present invention relates to a camera module, and more particularly, having a wavefront generating mirror in which the wavefront is controlled by an electrical signal, and packaging the surface protection cap on the wavefront generating mirror to move the lens under the control of the driving unit. The present invention relates to a camera module for improving a focus forming structure and a manufacturing method thereof.

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, the lens focus is adjusted by the conventional drive unit.

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 operation reliability 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 power consumption is increased, so the battery capacity must be large This remains.

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, in assembling the housing portion of the camera module, the light conversion element and the wavefront generating mirror implemented on the substrate, the assembly process of each component is simplified by having a surface protection cap to protect the surface of the wavefront generating mirror 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, adjusting a reflection angle on the subject, adjusting a focus on the subject according to an applied voltage, and including a surface protection cap; And an optical conversion element for converting the light signal on the reflected subject into an electrical signal.

In addition, the surface protection cap of the camera module according to the invention is characterized in that it comprises a cap adapter and a cover glass.

In addition, the optical conversion element and the wavefront generating mirror of the camera module according to the present invention is characterized in that it is integrally assembled to a flexible printed circuit board.

In addition, the optical conversion device and the wavefront generating mirror of the camera module according to the present invention are each mounted on a rigid printed circuit board, each of the rigid printed circuit board mounted with the light conversion device and the wavefront generating mirror is a flexible printing. It is characterized by being connected by a circuit board.

In addition, the wavefront generating mirror of the camera module according to the present invention is characterized in that for reflecting the subject image so that the path of the light passing through the lens portion and the path of the light incident on the light conversion element perpendicular to each other.

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 addition, the wavefront generating mirror of the camera module according to the invention is characterized in that located behind the lens unit.

In order to achieve the above object, the camera module manufacturing method according to the present invention relates to a camera module including a housing portion, a lens portion, a wavefront generating mirror and a light conversion element, the optical circuit on the printed circuit board in the array state Mounting a conversion element and the wavefront generating mirror; Assembling a surface protection cap to the wavefront generating mirror; Coupling a printed circuit board area on which the photoconversion device is mounted, to the housing part; Separating the printed circuit board area on which the wavefront generating mirror is mounted from the substrate array; And assembling the printed circuit board area of the separated wavefront generating mirror to the housing part.

In addition, the mounting of the optical conversion element and the wavefront generating mirror of the camera module manufacturing method according to the present invention, characterized in that further comprising the step of wire bonding the light conversion element and the wavefront generating mirror.

In addition, the step of assembling the surface protection cap to the wavefront generating mirror in the camera module manufacturing method according to the present invention, the cover glass and the cap adapter is assembled to produce the surface protection cap and the produced surface protection cap is Assembling to the wavefront generating mirror.

Further, in the method of manufacturing the camera module according to the present invention, the optical conversion element and the wavefront generating mirror are mounted on the printed circuit board in the array state, wherein the plurality of rigid printed circuit boards and the plurality of flexible printed circuit boards are interconnected. And manufacturing the printed circuit board in the array state, and mounting the light conversion element and the wavefront generating mirror to the different rigid printed circuit boards, respectively.

In addition, the step of assembling the printed circuit board area of the separated wavefront generating mirror in the housing portion of the camera module manufacturing method according to the present invention, the flexible printed circuit board is bent by bending the printed circuit board of the separated wavefront generating mirror. The area is moved to the housing side and assembled.

In addition, the step of assembling the printed circuit board region of the separated wavefront generating mirror in the housing portion of the camera module manufacturing method according to the present invention is characterized in that the step of assembling by UV (ultraviolet) bonding method.

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, an optical 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 housing area a1 of 110 and the housing area a2 of the wavefront generating mirror are formed adjacent to each other, and the housing area a3 of the light conversion element 130 is formed below.

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 so as 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, and the first lens 112 may have negative refractive power. 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 power and extends the light passing through the first lens 112, and has a meniscus shape convexly toward the subject 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 having 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 part (a) during use, there is a risk that its 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 surface protection cap 160, the configuration and the manufacturing method associated with it will be described with reference to FIGS.

4 is a flowchart illustrating a method of manufacturing a camera module according to the present invention, and FIG. 5 illustrates a first process state of the camera module before assembling the wavefront generating mirror 120 and the light conversion element 130 according to the present invention. The figure is shown.

First, the optical conversion device 130 and the wavefront generating mirror 120 are mounted on the printed circuit board 170 in an array state (S100), and the lens unit 110 and the IR filter 150 are mounted on the housing part a. Is installed.

The printed circuit board 170 in the array state refers to a state in which a plurality of rigid printed circuit boards and flexible printed circuit boards are arranged and connected to simultaneously process a plurality of camera module manufacturing processes.
That is, as shown in Figure 5, in order to manufacture a camera module requires at least two rigid printed circuit boards (172, 176) and one flexible printed circuit board 174 connecting them, such printing The circuit boards 172, 174, and 176 may be connected in a group to form an array state (for convenience of description, FIGS. 5 and 6 show one group of printed circuit boards 170 in an array state). Only printed circuit boards 172, 174, and 176 are shown).
The light conversion element 130 and the wavefront generating mirror 120 are mounted on each of the rigid printed circuit boards 172 and 176 of the printed circuit board 170 in the array state.

Subsequently, the photoconversion device 130 and the wavefront generating mirror 120 are wire bonded on the respective hard printed circuit boards 172 and 176 (S200).

Before the photoconversion device 130 and the wavefront generating mirror 120 are coupled to the housing portion a, the surface protection cap 160 should be assembled on the wavefront generating mirror 120, and the surface protection cap 160 The cover glass 162 and the cap adapter 164 is assembled (S300).

FIG. 6 is a view illustrating a second process state of the camera module before the wavefront generation mirror 120 and the light conversion element 130 according to the present invention are assembled.

As shown in FIG. 6, the rigid printed circuit board 172 on the side of the light conversion element 130 is coupled to the bottom surface side of the housing part a, and the wavefront generating mirror 120 has a surface protective cap 160. It is combined with (S400).

When the rigid printed circuit board 172 on the side of the light conversion element 130 is coupled to the housing part a, the rigid printed circuit board 176 on the side of the flexible printed circuit board 174 and the wavefront generating mirror 120 is provided. Is exposed to the outside, and the rigid printed circuit board 176 on which the wavefront generating mirror 120 is mounted is separated from the substrate array to be coupled to the housing part a.

Subsequently, a part of the flexible printed circuit board 174 is bent to move the rigid printed circuit board 176 on which the wavefront generating mirror 120 is positioned to a coupling position with the upper housing part a2 (S500).

As described above, the rigid printed circuit board 176 of the wavefront generating mirror 120 that is moved to the coupling position with the housing part a2 is the optical axis of the lens unit 110 and the incident optical axis of the light conversion element 130. It is coupled to the housing portion region a2 to form a reflection angle of 45 degrees with (S600).

At this time, the rigid printed circuit board 176 on the wavefront generating mirror 120 side is coupled to the housing portion region a2, and is preferably coupled by a UV (ultraviolet) bonding method.
Thereafter, the rigid printed circuit board 172 on the side of the light conversion element 130 may be separated from the substrate array to complete the camera module.

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 wavefront generation 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 (15)

A lens unit refracting light to form an object image; A wavefront generating mirror for reflecting a subject image refracted on the lens unit, adjusting a reflection angle on the subject, adjusting a focus on the subject according to an applied voltage, and including a surface protection cap; And A camera module comprising a light conversion element for converting the light signal on the reflected subject to an electrical signal. The method of claim 1, wherein the surface protective cap Camera module comprising a cap adapter and a cover glass. The method of claim 1, wherein the light conversion element and the wavefront generating mirror Camera module, characterized in that integrated on the flexible printed circuit board. The method of claim 1, The photoconversion device and the wavefront generating mirror are each mounted on a rigid printed circuit board, and each of the rigid printed circuit boards on which the photoconversion device and the wavefront generating mirror are mounted is connected by a flexible printed circuit board. Camera module. The method of claim 1, wherein the wavefront generating mirror And reflecting the subject image such that a path of light passing through the lens unit and a path of light incident on the light conversion element are perpendicular to each other. 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. The method of claim 1, wherein the wavefront generating mirror Camera module, characterized in that located behind the lens unit. The method of claim 1, wherein the wavefront generating mirror The camera module, characterized in that the wavefront power value of the reflecting surface is adjusted according to the externally applied voltage. A camera module comprising a housing portion, a lens portion, a wavefront generating mirror, and an optical conversion element, Mounting the optical conversion element and the wavefront generating mirror on a printed circuit board in an array state; Assembling a surface protection cap to the wavefront generating mirror; Coupling a printed circuit board area on which the photoconversion device is mounted, to the housing part; Separating the printed circuit board area on which the wavefront generating mirror is mounted from the substrate array; And And assembling the printed circuit board area of the separated wavefront generating mirror to the housing part. The method of claim 10, wherein the optical conversion element and the wavefront generating mirror are mounted. The optical conversion device and the wavefront generating mirror further comprises the step of wire bonding the camera module manufacturing method. The method of claim 10, wherein the surface protection cap is assembled to the wavefront generating mirror; Cover glass and cap adapter are assembled to manufacture the surface protection cap; and The manufacturing method of the camera module comprising the step of assembling the produced surface protection cap to the wavefront generating mirror. The method of claim 10, wherein the optical conversion element and the wavefront generating mirror are mounted on the printed circuit board in the array state. Manufacturing a plurality of rigid printed circuit boards and a plurality of flexible printed circuit boards by interconnecting the printed circuit boards in the array state; Manufacturing the camera module comprising the step of mounting the optical conversion element on the rigid printed circuit board of one of the rigid printed circuit boards connected by the flexible printed circuit board, and the wavefront generating mirror on the other rigid printed circuit board. Way. The method of claim 13, wherein the step of assembling the printed circuit board area of the separated wavefront generating mirror in the housing portion And bending the flexible printed circuit board to move the printed circuit board area of the separated wavefront generating mirror to the housing part to be assembled. The method of claim 10, wherein the step of assembling the printed circuit board area of the separated wavefront generating mirror in the housing portion, Camera module manufacturing method, characterized in that the step of assembling by UV (ultraviolet) bonding method.

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