JP2005012327A - Image pick-up unit and its assembling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image pick-up unit which can hardly have an influence of an electromagnetic wave and which can hardly impart an influence of the electromagnetic wave, and to provide a method for assembling the image pick-up unit which can raise the quality while corresponding to an environmental change. <P>SOLUTION: Since the image pick-up unit disposes a conductive member 106 between a barrel 101 and an imaging element 107, the conductive member 106 can obtain a high quality image by making it hard to reach the imaging element 107 in the electromagnetic wave which comes flying from taking an imaging lens 102 side. Since the electromagnetic wave generated from the imaging element 107 can be made hard to project to an exterior, the image pick-up unit 100 becomes suitable to carry in a communication device, such as, for example, a portable telephone, etc., by performing such a shielding effect. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an imaging unit and an assembling method thereof, and more particularly to an imaging unit that can be mounted on a mobile phone, a personal computer (personal computer), and the like and an assembling method thereof.
[0002]
[Prior art]
In recent years, it has become possible to easily handle digital image data due to higher performance of CPUs and development of image processing technology. In particular, in mobile phones and PDAs (Personal Digital Assistants), models with a display capable of displaying images are on the market, and in the near future, a dramatic improvement in wireless communication speed can be expected. It is expected that image data will frequently be transferred between them.
[0003]
Recently, as described in Patent Document 1, a small-sized imaging unit in which a solid-state imaging device such as a CCD is attached to a lens barrel has been developed.
[Patent Document 1]
Japanese Patent Application Laid-Open No. 9-135010
[Problems to be solved by the invention]
By the way, such an imaging unit has the following problems. First, recent imaging units are often mounted on mobile phones, communication terminals, etc. In that case, the image signal output from the image sensor is easily affected by noise due to radio waves at the time of communication. Noise generated from the element may adversely affect communication.
[0005]
Furthermore, in the imaging unit, there is a problem of how to assemble a lens barrel for fixing a photographing lens and an imaging element. In Patent Document 1 described above, positioning is achieved by placing a bare chip CCD on a substrate and pressing the substrate against a reference surface of a lens barrel. However, there is a problem that the cost of the lens barrel increases when the reference surface is formed with high accuracy. In addition, when the substrate is pressed against the reference surface and then fixed to the lens barrel using an adhesive, the adhesive is easily deformed locally due to temperature and humidity. Problems such as floating of the substrate are also expected, and the resulting image may have a low image quality. Further, when repairing the image pickup device or the taking lens, if the lens barrel and the image pickup device are bonded, they must be exchanged together, which causes a problem that the burden on the user becomes excessive.
[0006]
The present invention has been made in view of these problems, and is an imaging unit that is not easily affected by electromagnetic waves and is less susceptible to electromagnetic waves, and an imaging unit that can achieve high image quality while responding to environmental changes. The purpose is to provide an assembly method.
[0007]
[Means for Solving the Problems]
An imaging unit according to a first aspect of the present invention includes an imaging lens, a lens barrel that holds the imaging lens, an imaging element that receives subject light through the imaging lens and converts it into an image signal, and a substrate on which the imaging element is attached. And a conductive member disposed between the lens barrel and the imaging device, the conductive member makes it difficult for electromagnetic waves flying from the outside to reach the imaging device, thereby providing a high-quality image. In addition, it is possible to make it difficult to project the electromagnetic wave generated by the imaging device to the outside, and therefore, it is suitable for mounting on a communication device such as a mobile phone. The “conductive member” is not limited to a metal, but also includes those formed from a non-metal having conductivity. Examples of such a conductive resin include a carbon fiber or a conductive resin plated on the surface. And conductive ceramics.
[0008]
Further, an elastic member is disposed between the lens barrel and the conductive member. When the conductive member is screwed to the lens barrel at two or more locations, at least one screw is provided. By adjusting the tightening amount (tilt adjustment or the like), the image sensor can be arbitrarily positioned. As the “elastic member”, rubber, resin, foaming elastic body, or the like can be used.
[0009]
Furthermore, when the conductive member is grounded to the ground of the substrate, the influence of electromagnetic waves can be further suppressed.
[0010]
Further, when at least one surface of the substrate is subjected to a conductive treatment, the influence of electromagnetic waves can be further suppressed.
[0011]
Furthermore, when a transparent conductive member is disposed so as to cover the imaging surface of the imaging element, the influence of electromagnetic waves can be further suppressed. Note that “transparent” does not necessarily mean that the light transmittance is 100%, and it is sufficient if the light transmittance is at least 50%.
[0012]
The method of assembling the imaging unit of the second aspect of the invention is a method of assembling an imaging element to a lens barrel holding a photographing lens, and joining a plate-like conductive member to a surface of the imaging element on the lens barrel side. And a step of interposing an elastic member between the conductive member and the lens barrel, temporarily fixing the conductive member to the lens barrel using a screw, and an image signal output from the imaging device Then, positioning the image sensor while adjusting the tightening amount of the screw, and performing a screw locking process, the lens barrel, i.e., even if a temperature change or a humidity change occurs. The positional relationship between the photographic lens and the image pickup element is unchanged, so that a high-quality image can be obtained stably over a long period of time. In addition, even when repairing an image sensor or a photographic lens, the image sensor can be separated from the lens barrel by loosening the screw, and the burden on the user can be reduced by reusing a normal one. Can be reduced. The “loosening prevention process” means that a curable resin is applied to the screw or a part of the screw is deformed to increase the frictional force, but is not limited thereto.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a rear view of the imaging unit 100 according to the first embodiment, but a flexible substrate is omitted. 2 is a cross-sectional view of the configuration of FIG. 1 taken along the line II-II and viewed in the direction of the arrow. FIG. 3 is a diagram of the image pickup device of the image pickup unit 100 as viewed in the direction of arrow III.
[0014]
In FIG. 2, a rectangular tube-shaped lens barrel 101 has a photographing lens 102 (the lens frame is shown in a simplified manner) fixedly held therein, and an opening 103a is provided at the left opening end in FIG. A fixing plate 103 is bonded, and a cover glass 104 for protecting the photographing lens 102 is bonded to the fixing plate 103.
[0015]
In the lens barrel 101, a conductive member 106 is attached to the opening end on the right side in FIG. The imaging element 107 has an imaging unit 107a at the center, and an optical filter 108 is bonded so as to cover the imaging unit 107a. The elastic member 105 and the conductive member 106 have a rectangular opening at the center, that is, a frame plate shape so as not to block light incident through the photographing lens 102.
[0016]
Further, a flexible substrate 109 is attached to the back surface of the image sensor 107 so that an image signal can be output via the printed wiring. As shown in FIG. 3, the ground of the flexible substrate 109 is grounded by being soldered (S) to the conductive member 106.
[0017]
As shown in FIG. 1, the conductive member 106 is attached to the back surface of the lens barrel 101 using three screws 110A, 110B, and 110C. Instead of soldering, the conductive member 106 may be grounded by screwing together.
[0018]
Next, a method for assembling the imaging unit 100 will be described. In advance, the photographing lens 102 is fixed to the lens barrel 101, and the fixing plate 103 to which the cover glass 104 is attached is assembled. In addition, the imaging element 107 installed on the flexible substrate 109 is bonded to the conductive member 106. Thereafter, the conductive member 106 is temporarily fixed to the lens barrel 101 using screws 110A, 110B, and 110C.
[0019]
In such a state, an optical image such as a test pattern can be formed on the image pickup unit 107a of the image pickup element 107 via the photographing lens 102. Therefore, by connecting the flexible substrate 109 to an image processing device (not shown), The obtained image can be observed. From the state of the test image, it is possible to determine the tilted state (tilted with respect to the optical axis) of the image sensor 107, so that any one of the screws 110A, 110B, and 110C is tightened or loosened so as to be corrected. Then, the image sensor 107 is positioned for each conductive member 106.
[0020]
By performing the above adjustment, the image sensor 107 is appropriately positioned with respect to the lens barrel 101 (the optical axis of the photographing lens 102), and then the adhesive is applied to the outer periphery of the screws 110A, 110B, and 110C, thereby providing conductivity. A loosening prevention process is performed on the member 106. In addition, since the amount of this adhesive is small, the effect as a loosening prevention is sufficient, but if the screws 110A, 110B, 110C are rotated with a screwdriver, they can be easily peeled off, making disassembly and repair difficult. It is not a thing.
[0021]
According to the present embodiment, since the conductive member 106 is disposed between the lens barrel 101 and the imaging element 107, the conductive member 106 is unlikely to reach the imaging element 107 with electromagnetic waves flying from the photographing lens 102 side. By doing so, it is possible to obtain a high-quality image, and it is possible to make it difficult to project the electromagnetic wave generated by the imaging element 107 to the outside. It is suitable for mounting on a communication device such as a mobile phone. Further, if a conductive treatment such as plating is performed on the back surface of the flexible substrate 109, the shielding effect on the back surface side of the image sensor 107 can be further exhibited.
[0022]
In addition, since the elastic member 105 is disposed between the lens barrel 101 and the conductive member 106, it is possible to prevent foreign substances such as dust from entering from between them. In addition, by providing the conductive member 106 between the lens barrel 101 and the imaging element 107 and fixing with the screws 110A, 110B, and 110C, the thickness of the imaging unit 100 in the optical axis direction can be suppressed.
[0023]
FIG. 4 is a diagram showing a modification of the present embodiment. In this modification, the optical filter 108 ′ disposed on the front surface of the imaging unit 107 a of the imaging element 107 is made conductive. For example, the optical filter 108 ′ is subjected to a thin and numerous line plating on the surface thereof, and the plating is grounded to the ground of the flexible substrate 109 (FIG. 3) via the conductive member 106 or a wire. According to this modification, there is an advantage that the electromagnetic filter 108 ′ disposed on the front surface of the imaging unit 107 a can efficiently shield the electromagnetic waves reaching the imaging unit 107 a.
[0024]
FIG. 5 is a cross-sectional view of the imaging unit 200 according to the second embodiment. The imaging unit 200 according to the present embodiment has a configuration capable of moving the photographic lens in the optical axis direction. More specifically, the imaging unit 200 will be described.
[0025]
In FIG. 5, a photographing lens (the lens frame is shown in a simplified manner) 202 is disposed inside a cylindrical lens barrel 201. Two shafts 221 and 221 each having one end attached to the lens barrel 202 and the other end embedded in a fixing plate 203 for fixing the cover glass 204 are arranged in parallel to the optical axis. The lens frame 202 partially fitted to the shafts 221 and 221 is movable in the optical axis direction. A coil spring 223 is disposed between the lens frame 202 and the fixed plate 203, and urges the lens frame 202 rightward in FIG.
[0026]
The lens frame 202 has an arm portion 202a extending from the outer periphery in the direction orthogonal to the optical axis. In the lens barrel 202, a motor 222 having a screw shaft 222a as a rotation axis is disposed. The screw shaft 222a is screwed into the arm portion 202a.
[0027]
In the lens barrel 201, a conductive member 206 to which an image sensor 207 is bonded is attached to the right opening end in FIG. 5 with screws 210 </ b> A and 210 </ b> B via an elastic member 205. An optical filter 208 is bonded so as to cover the front surface of the image sensor 207. A flexible substrate 209 is attached to the back surface of the image sensor 207 so that an image signal can be output via the printed wiring.
[0028]
For example, in a state where the imaging unit 200 is incorporated in a mobile phone or the like, it is possible to detect whether or not the image is in focus by performing image processing on an image signal output from the imaging element 207 with an image processing device (not shown). Accordingly, if the motor 222 is driven, the photographic lens (frame) 202 can be moved to the optimum focus position. At this time, since the lens frame 202 is urged by the coil spring 223, play between the screw shaft 222a and the arm portion 202a is eliminated. Other effects are the same as in the above-described embodiment.
[0029]
The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate. The imaging unit of the present invention can be incorporated into various types such as a mobile phone, a personal computer, a PDA, an AV device, a television, and a home appliance.
[0030]
【The invention's effect】
According to the present invention, it is possible to provide an imaging unit that is not easily affected by electromagnetic waves and hardly affected by electromagnetic waves, and a method for assembling an imaging unit that can achieve high image quality while responding to environmental changes.
[Brief description of the drawings]
FIG. 1 is a rear view of an imaging unit 100 according to a first embodiment.
2 is a cross-sectional view of the configuration of FIG. 1 taken along line II-II and viewed in the direction of the arrows.
3 is a diagram of an image sensor of the imaging unit 100 as viewed in the direction of arrow III. FIG.
FIG. 4 is a diagram showing a modification of the present embodiment.
FIG. 5 is a cross-sectional view of an imaging unit 200 according to the second embodiment.
[Explanation of symbols]
100, 200 Imaging unit 101, 201 Lens barrel 102, 202 Shooting lens (frame)
103, 203 Fixed plate 105, 205 Elastic member 106, 206 Conductive member 107, 207 Imaging element 108, 108 ', 208 Optical filter 109, 209 Flexible substrate 110A-110C, 210A, 210B Screw 221 Shaft 222 Motor 223 Screw

Claims (6)

A taking lens,
A lens barrel holding the photographing lens;
An image sensor for receiving subject light through the photographing lens and converting it into an image signal;
A substrate to which the image sensor is attached;
An imaging unit comprising: a conductive member disposed between the lens barrel and the imaging device. 2. An elastic member is disposed between the lens barrel and the conductive member, and the conductive member is screwed to the lens barrel at two or more locations. The imaging unit described in 1. The imaging unit according to claim 1, wherein the conductive member is grounded to a ground of the substrate. The imaging unit according to claim 1, wherein at least one surface of the substrate is subjected to a conductive process. The imaging unit according to claim 1, wherein a transparent conductive member is disposed so as to cover an imaging surface of the imaging element. In the method of assembling the image sensor to the lens barrel holding the taking lens,
Bonding a plate-like conductive member to the lens barrel side surface of the imaging device;
Interposing an elastic member between the conductive member and the lens barrel, and temporarily fixing the conductive member to the lens barrel using a screw;
Positioning the image sensor while adjusting the tightening amount of the screw based on the image signal output from the image sensor;
A method for assembling the imaging unit, comprising: performing a screw locking process.

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