JP2010177837A - Image capturing module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of a connecting portion to a rear case of a connection end portion of an external cable, and to simplify the structure of the connecting portion to the rear case of the connection end portion of the external cable so as to airtight the inner space of an imaging module. Retain sex.
An imaging module 1 includes a front case 3 in which a lens unit 2 is mounted on a subject side and an imaging board 12 is installed on a portion opposite to the subject side, and an imaging board 12 attached to the front case 3. The rear case 4 is sealed in the inner space with the front case 3, and the connection cable 5 is connected to the rear case 4 through the through hole 6b of the bracket 6 and the external cable attached to the rear case 4. The external cable has a flange 6 a sandwiched between the attachment surface of the rear case 4 and the peripheral portion of the opening of the through hole 6 b of the bracket 6 at the connection end 5, and the bracket 6 is screwed to the attachment surface of the rear case 4. And attached to the rear case 4.
[Selection] Figure 2

Description

  The present invention relates to an imaging module using an imaging device composed of a semiconductor image sensor such as a CCD image sensor.

  A conventional imaging module having a bracket for mounting to an automobile or the like has the following configuration, for example. A front case in which the lens unit is mounted on the subject side, and an imaging board on which the image sensor is mounted is installed on the opposite side of the subject side with the image sensor facing the lens unit, and attached to the front case A rear case that seals the imaging board in the inner space with the front case, and a connection end (plug harness) to the rear case having an external cable attached to the rear case through the through hole of the bracket. The connection end of the external cable and the rear case are screwed together, and the connection end of the external cable and the bracket are screwed together.

JP 2007-261503 A

  However, in the above-described conventional imaging module, the connection end of the external cable and the rear case are screwed together, and the connection end of the external cable and the bracket are screwed together. Screw-in structure. As a result, there is a problem that the connecting portion of the connection end portion of the external cable to the rear case becomes large and the imaging module itself becomes large.

  Further, since the structure is a two-stage screwing structure, the structure of the connecting portion of the connection end portion of the external cable to the rear case is complicated, and a minute gap is likely to be generated. Therefore, there is a problem that it is difficult to maintain the airtightness of the inner space of the imaging module.

  Therefore, the present invention has been devised in view of the above-described conventional problems, and its purpose is to downsize the imaging module itself by downsizing the joint portion of the connection end of the external cable to the rear case. In addition, by simplifying the structure of the connecting portion of the connection end portion of the external cable to the rear case so that a minute gap is not easily generated, the airtightness of the inner space of the imaging module can be maintained. Is to do.

  In the imaging module of the present invention, the lens unit is mounted on the subject side, and an imaging board on which the imaging element is mounted is installed at a portion opposite to the subject side with the imaging element facing the lens unit. A front case, a rear case attached to the front case and sealing the imaging substrate in an inner space of the front case, and a connection end portion of the rear case to the rear case through a through hole of a bracket An external cable attached, and the external cable has a flange that is sandwiched between the attachment surface of the rear case and the periphery of the opening of the through hole of the bracket at the connection end. The bracket is screwed to the mounting surface of the rear case and is attached to the rear case.

  In the imaging module of the present invention, in the configuration described above, a sealing member is provided in the gap so as to surround the flange portion outside the flange portion in the gap between the mounting surface of the rear case and the bracket. It is characterized by being filled.

  According to the image pickup module of the present invention, the lens unit is mounted on the subject side, and the image pickup board on which the image pickup device is mounted is installed in a portion opposite to the subject side with the image pickup element facing the lens unit. The front case, the rear case attached to the front case and sealing the imaging board in the space inside the front case, and the external cable where the connection end of the rear case is attached to the rear case through the through hole of the bracket The external cable has a flange that is sandwiched between the attachment surface of the rear case and the periphery of the opening of the through hole of the bracket at the connection end, and the bracket is attached to the attachment surface of the rear case. Since it is screwed and attached to the rear case, the bracket is screwed to the mounting surface of the rear case, and at the same time it is The flange portion is pressed against the mounting surface of the rear case Te would be attached to the rear case also connecting end portions of the external cables. That is, a one-stage screwing structure is provided. Accordingly, the connecting portion of the connection end portion of the external cable to the rear case is downsized, and the imaging module itself is downsized. In addition, since the structure of the connecting portion with respect to the rear case of the connection end portion of the external cable is simplified and a minute gap is hardly generated, the airtightness of the inner space of the imaging module can be maintained.

  In the imaging module of the present invention, in the above configuration, when the sealing member is filled in the gap so as to surround the flange on the outer side of the flange in the gap between the mounting surface of the rear case and the bracket. The sealing member further improves the airtightness of the inner space of the imaging module.

(A) is a side view showing an example of an embodiment of the imaging module of the present invention, (b) is a front view of the imaging module as viewed from the F direction (front direction) of (a), and (c) is a diagram of (a). It is a rear view of the imaging module seen from the R direction (rear direction). It is sectional drawing which shows the arrow cross section in the AA cut line of FIG.1 (b) about the imaging module shown in FIG. It is sectional drawing which shows the arrow cross section in the BB cutting line of FIG.1 (b) about the imaging module shown in FIG. It is sectional drawing which shows the arrow cross section in the CC cutting line of FIG.1 (c) about the imaging module shown in FIG.

  Hereinafter, embodiments of an imaging module of the present invention will be described in detail with reference to the drawings.

  1 to 4 show an example of an embodiment of an imaging module of the present invention, FIG. 1A is a side view of the imaging module of the present embodiment, and FIG. 1B is an F direction (front) of FIG. (C) is a rear view of the imaging module viewed from the R direction (rear direction) of (a). FIG. 2 is a cross-sectional view showing the cross section taken along the line AA in FIG. 1B for the imaging module of the present embodiment of FIG. FIG. 3 is a cross-sectional view showing a cross section taken along the line BB of FIG. 1B for the imaging module of the present embodiment of FIG. FIG. 4 is a cross-sectional view showing the cross section taken along the line CC of FIG. 1C for the imaging module of the present embodiment of FIG.

  In the imaging module 1 of the present embodiment, the lens unit 2 is mounted on the subject side, and the imaging substrate 12 on which the imaging element 11 is mounted is opposite to the subject side with the imaging unit 11 facing the lens unit 2. The front case 3 installed at the site, the rear case 4 attached to the front case 3 and sealing the imaging substrate 12 in the inner space of the front case 3, and the connecting end (plug) (Harness) 5 includes an external cable (not shown) attached to the rear case 4 through the through hole 6 b of the bracket 6, and the external cable is connected to the connection end 5 at the attachment surface of the rear case 4 and the bracket 6. The through-hole 6b has a flange 6a that is sandwiched by the periphery of the opening of the through-hole 6b. The bracket 6 is screwed to the mounting surface of the rear case 4 and attached to the rear case 4.

  With the above configuration, the bracket 6 is screwed to the mounting surface of the rear case 4 and at the same time, the flange portion 6a is pressed against the mounting surface of the rear case 4 by the peripheral portion of the opening of the through hole 6b of the bracket 6 to connect the external cable. The end portion 5 is also attached to the rear case 4. That is, a one-stage screwing structure is provided. Accordingly, the connecting portion of the external cable connection end 5 to the rear case 4 is downsized, and the imaging module 1 itself is downsized. Further, since the structure of the connecting portion of the connection end 5 of the external cable to the rear case 4 is simplified and a minute gap is less likely to be generated, the airtightness of the inner space of the imaging module 1 can be maintained. .

  Such an imaging module 1 is used for in-vehicle use, for example, and has a function of imaging a white line on a road or imaging a blind spot of a driver who drives a vehicle, and controlling an automobile (ECU) The operation is controlled by an electronic control unit). The electrical signal output from the imaging module 1 is converted into an image signal by the ECU, and displayed on a display installed in front of the driver's seat, for example.

  The image sensor 11 is a semiconductor image sensor element such as a CCD image sensor or a CMOS image sensor.

  The lens unit 2 has a function of condensing light from a subject on the image sensor 11, for example, a first lens having a convex shape on the front side in order to collect light at a wide angle, and a first lens The lens group is composed of a second lens and a third lens for bringing light that has passed through the lens closer to parallel as light rays. When the lens unit 2 includes the above-described three lenses, for example, the first lens, the second lens, and the third lens from the front side (the subject side and F side in FIG. 1A). It arrange | positions so that it may overlap in an optical axis direction in order. The lens unit 2 may have four or more lenses.

  The case attaches and supports the lens unit 2 located on the front side. The case is divided into a front case 3 and a rear case 4, and these are integrally attached. The front case 3 is, for example, an annular retainer (not shown) as a pressing member that is disposed on the front side and presses the first lens of the lens unit 2 to the back side (opposite the subject side), and the back surface of the retainer The lens holder 10 is composed of a generally cylindrical lens barrel 10 as a lens holder disposed on the side. The second lens and the third lens are fixed to the lens barrel 10 of the front case 3, and the first lens is fixed so as to be pressed against the lens barrel 10 by a retainer.

  These retainers and lens barrels are produced, for example, by the method described below.

  The lens barrel 10 is prepared by preparing a mold for injection molding having a cavity provided in accordance with the shape of the lens barrel 10, and pouring the raw material for the lens barrel 10 into the cavity and solidifying it. It can be manufactured using an injection molding method in which a predetermined shape is formed by molding. Similarly, the retainer is prepared by preparing a mold for injection molding having a cavity formed in a shape that matches the shape of the retainer, pouring the raw material for the retainer into the cavity, and solidifying the mold. Can be formed into a predetermined shape. Such a retainer and the lens barrel 10 are made of an insulating resin such as polycarbonate (PC) or polyphthalamide (PPA), for example, to reduce the weight. Usually, in order to match the thermal expansion and thermal contraction of the retainer and the lens barrel 10, it is preferable to use the same material for both.

  An imaging substrate 12 is attached to the back side of the imaging module 1. An imaging element 11 housed in a package made of ceramics, resin, or the like is installed on the main surface on the front side of the imaging substrate 12.

  The image pickup element 11 is attached to the case by mounting the image pickup element 11 on the main surface on the front side of the image pickup substrate 12 and attaching the image pickup substrate 12 to the front case via a connection terminal, solder, or the like.

  The imaging substrate 12 is formed of, for example, a printed wiring board formed by impregnating a glass cloth with an epoxy resin or by adding a glass filler to an epoxy resin. On the surface or inside of the imaging substrate 12, an electrical connection with a terminal such as another component different from the mounted imaging element 11, or a wiring conductor for fixing them and a ground wiring for grounding are formed. For such wiring conductors and ground wirings, a method of forming a conductive metal such as copper or gold by a plating method, a method of bonding a metal foil previously formed in a wiring pattern shape, or a metal foil is deposited on the entire surface It is formed on the surface of the printed wiring board or inside by using a method of etching away unnecessary portions from the substrate by etching.

  Such an imaging substrate 12 is prepared, for example, a commercially available copper-coated substrate with a copper foil deposited on the entire front and back surfaces, and the substrate is cut into a desired size, and the copper foil deposited on the surface is diluted with dilute hydrochloric acid or the like. It is manufactured by etching a desired wiring pattern with an acidic solution. If necessary, a through hole is formed using a laser or a drill, and the through hole is filled with a metal paste to embed the through conductor, thereby electrically connecting the wiring patterns on the front and back of the board. Is possible.

  On the main surface on the back side of the imaging board 12, an IC (not shown) that processes an electrical signal from the imaging element 11, and a cable (not shown) that electrically connects the wiring conductor of the imaging board 12 and the ECU. ) May be mounted such as a connector (not shown).

  The rear case 4 can be manufactured using an injection molding method in the same manner as the front case 3. That is, an injection mold having a cavity provided in accordance with the shape of the rear case 4 is prepared, and the raw material for the rear case 4 is poured into the cavity to be solidified and molded. Form into shape.

  The bracket 6 is a plate-like projecting portion for attaching the imaging module 1 to an external machine or device such as an automobile, and has a through-hole 8 for attaching to the external machine or device by screwing or the like. ing. The shape of the bracket 6 is not limited to a plate shape, and may be a shape having a side wall portion that protects the case, for example, a plate shape, a box shape, or the like. The bracket 6 is made of a resin such as polycarbonate (PC) or polyphthalamide (PPA), a metal such as stainless steel, copper, or aluminum.

  The connection end 5 of the external cable is attached to the back side (rear side) of the rear case 4 in the configuration of FIGS. 1 to 4, but may be attached to the side surface of the rear case 4. The connection end portion (plug harness) 5 of the external cable is made of, for example, an insulating resin such as polycarbonate (PC) or polyphthalamide (PPA).

  In the imaging module 1 of the present embodiment, the external cable has a flange portion 6 a sandwiched between the attachment surface of the rear case 4 and the peripheral portion of the opening of the through hole 6 b of the bracket 6 at the connection end portion 5. The width of the flange portion 6a is preferably about 3 mm to 5 mm. By being within this range, the connection end 5 of the external cable is firmly attached to the rear case 4, and the coupling of the external cable connection end 5 to the rear case 4 due to the excessively large width of the flange 6a. It can suppress that a part enlarges. Further, the thickness of the flange portion 6a is preferably about 0.8 mm to 1.2 mm. By being within this range, the connection end 5 of the external cable is firmly attached to the rear case 4, and the connection of the external cable connection end 5 to the rear case 4 due to the thickness of the flange 6a being too thick. It can suppress that a part enlarges.

  Moreover, the collar part 6a may be formed over the perimeter of the periphery of the through-hole 6b, or may be formed so that it may partially exist around the through-hole 6b. When the collar portion 6a is formed so as to partially exist around the through-hole 6b, it is preferably formed so as to have a symmetrical shape. In that case, when attaching the connection end 5 of the external cable to the attachment surface of the rear case 4, misalignment, bias, inclination, and the like are unlikely to occur.

  An annular cushion member made of an elastic material such as rubber is sandwiched between the flange 6a and the mounting surface of the rear case 4 or between the flange 6a and the periphery of the opening of the through hole 6b of the bracket 6. It may be. In that case, the connection end 5 of the external cable can be firmly attached to the rear case 4, and the airtightness of the inner space of the imaging module 1 can be improved.

  The flange portion 6a can be formed simultaneously when the connection end portion (plug harness) 5 of the external cable is produced by the injection molding method described above. That is, an injection mold having a cavity provided in accordance with the shape of the connection end 5 of the external cable having the flange 6a is prepared, and the raw material is poured into the cavity to be solidified and molded. Thus, it can be manufactured using an injection molding method for forming a predetermined shape.

  Further, in the imaging module 1 of the present embodiment, a sealing member is filled in the gap so as to surround the flange 6a on the outside of the flange 6a in the gap between the mounting surface of the rear case 4 and the bracket 6. Preferably it is. In this case, the airtightness of the inner space of the imaging module 1 is further improved by the sealing member. This sealing member is made of an O-ring, packing, or the like made of an elastic material such as rubber. Alternatively, the sealing member may be made of an adhesive such as a resin adhesive.

  In the imaging module 1 of the present embodiment, it is preferable that the rear case 4 accommodates the imaging substrate 12 in which the imaging element 11 is positioned with respect to the lens unit 2 inside. In this case, the positioned imaging substrate 12 can be protected by the rear case 4, and the case made up of the front case 3 and the rear case 4 can be reduced in size. Further, the inner space of the case is only the inner side of the rear case 4, and the inner space of the case can be reduced.

  An embodiment of the imaging module of the present invention will be described below.

  The imaging module of this example having the configuration shown in FIGS. 1 to 4 was produced as follows. First, a rectangular cylindrical front case 3 made of polycarbonate formed by an injection molding method and a square box-shaped rear case 4 made of polycarbonate were prepared. The front case 3 has a rectangular cross section of 25 mm in length and 25 mm in width and a height of 12 mm. The rear case 4 has a square cross section of 25 mm in length and 25 mm in width. And having a height of 16 mm. The front case 3 has a cylindrical lens barrel 10 on the inner side, and the rear case 4 has a back surface (bottom surface of the box) as a mounting surface of the connection end 5 of the external cable.

  Next, the lens unit 2 composed of three lenses was attached to the lens barrel 10 inside the front case 3, and the lens unit 2 was fixed by an annular retainer. In addition, the conductive connection terminal provided outside the lens barrel 10 inside the front case 3 is inserted into the through hole of the imaging substrate 12 in which the imaging element 11 is installed on the main surface on the subject side. The imaging substrate 12 was attached to the front case by bonding conductive connection terminals to the electrode pads around the substrate via solder.

  Next, the rear case 4 was attached to the front case 3 by joining the opening at the front end of the rear case 4 to the opening at the rear end of the front case 3 with a screw. As a result, the imaging substrate 12 was sealed in the inner space constituted by the front case 3 and the rear case 4.

  Next, the cylindrical connection end (plug harness) 5 of the external cable having the flange 6a at the tip is passed through the through hole 6b of the plate-like bracket 6 made of polycarbonate, and the mounting surface of the rear case 4 and the bracket The flange portion 6a is sandwiched between the periphery of the opening of the six through holes 6b. The flange portion 6a is formed in a circular shape over the entire circumference of the tip of the connection end portion 5 and has a width of 0.8 mm and a thickness of 1.2 mm. Further, an O-ring made of rubber was attached to the outside of the flange portion 6a in the gap between the mounting surface of the rear case 4 and the bracket 6 so as to surround the flange portion 6a.

  Next, the bracket 6 is attached to the rear case 4 in a state where the flange 6a of the connection end 5 of the external cable is sandwiched between the attachment surface of the rear case 4 and the periphery of the opening of the through hole 6b of the bracket 6. The surface was fixed with screws 7. As a result, the rear case 4, the bracket 6, and the connection end 5 of the external cable were fixed at the same time.

  On the other hand, as Comparative Example 1, an imaging module having a configuration in which the connection end 5 of the external cable and the rear case 4 are screwed and the rear case 4 and the bracket 6 are screwed is manufactured. . The configuration of the portion other than the coupling structure of the connection end 5 of the external cable was the same as that of the imaging module 1 of the above embodiment. In this configuration, waterproofness is ensured, but size reduction cannot be achieved because the number of screwing points increases.

  As Comparative Example 2, the connection end 5 of the external cable was fixed to the rear case 4 by a claw (hook) provided on the rear case 4, and the bracket 6 was screwed to the rear case 4. In this configuration, the number of screwing points is reduced and the size can be reduced. However, since the claw portion is provided in the rear case 4, a step is generated on the contact surface of the sealing member 13, and the waterproof property is impaired. It became. The configuration of the portion other than the coupling structure of the connection end 5 of the external cable was the same as that of the imaging module of the above embodiment.

  As described above, both the imaging module of Comparative Example 1 and the imaging module of Comparative Example 2 cannot achieve both miniaturization and waterproofness.

  In addition, the imaging module 1 of the example and the imaging modules of Comparative Examples 1 and 2 were subjected to an airtight test using an air leak tester. Specifically, the airtightness test was performed by a differential pressure detection method in which air pressure was applied to the imaging module placed in the capsule from the outside of the imaging module to detect a change in air pressure in the capsule.

  As a result, the imaging module of the example and the imaging module of Comparative Example 1 each had an air leakage amount of about 0.4 when the desired reference value was 1.

  The imaging module of Comparative Example 2 had an air leakage amount of about 20 with respect to a desired reference value, and was inferior in airtightness to the imaging module 1 of the Example.

  Further, when the size of the imaging module 1 of the example and the imaging module of the comparative example 1 were compared by volume ratio, the imaging module 1 of the example was about 0.8 times the imaging module of the comparative example 1, and was downsized. It became a thing.

  The present invention is not limited to the above-described embodiment and examples, and various modifications may be made without departing from the scope of the present invention.

1: Imaging module 2: Lens unit 3: Front case 4: Rear case 5: Connection end of external cable 6: Bracket 6a: Gutter 6b: Through hole 7: Screw 11: Image sensor 12: Imaging substrate 13: Sealing Element

Claims (2)

  A front case in which a lens unit is mounted on a subject side, and an imaging board on which an imaging element is mounted is disposed on a portion opposite to the subject side with the imaging unit facing the lens unit; and the front case A rear case that is attached to the inner space of the front case and an external cable that is connected to the rear case through a through-hole of a bracket. The external cable has a flange portion sandwiched between a mounting surface of the rear case and a peripheral portion of the opening of the through hole of the bracket at the connection end portion, and the bracket is connected to the rear cable. An imaging module, wherein the imaging module is attached to the rear case by being screwed to a mounting surface of the case.   The sealing member is filled in the gap so as to surround the flange on the outer side of the flange in the gap between the mounting surface of the rear case and the bracket. Imaging module.

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