JP5543853B2 - Imaging device - Google Patents

Description

  The present invention relates to an imaging apparatus in which an imaging element is housed in a housing that holds a lens.

  In general, an imaging device such as an in-vehicle camera or a surveillance camera has a structure in which an imaging element is housed in a housing holding a lens. In this case, a front case and a rear case are formed separately to incorporate each member such as a lens and an image sensor, and the front case and the rear case are fixed after each member is assembled. . Here, the front case is a housing located on the lens side, and the rear case is a housing located on the imaging side.

  In a conventional imaging device, a member incorporated in the housing is fixed to either the front case or the rear case. For example, the lens bracket holding the lens and the circuit board are fixed and integrated, and then fixed to the rear case, and finally the front case is fixed to the rear case. In this case, all the members stored in the housing are fixed to the rear case side.

  As another structure, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2009-194543) discloses that a front case is provided with an opening for holding a lens and a post for attaching a substrate, and the lens and the circuit board are placed on the front case side. A configuration of an imaging device that is fixed is disclosed.

  In the conventional imaging apparatus as described above, first, each member such as a lens or a circuit board is incorporated in one of the cases, and at this time, adjustment of the distance between the lens and the imaging element (focus adjustment) and optical axis adjustment are performed. Finally, the other case is fixed. For example, in Patent Document 1, focus adjustment is performed by interposing a spacer between the post of the front case and the circuit board.

JP 2009-194543 A

However, the conventional imaging apparatus has a problem that maintenance is difficult because members are concentrated on one case. For example, when the housing member is fixed on the front case side as in Patent Document 1, if there is a problem with the lens, the circuit board cannot be removed once and the lens cannot be treated, and all must be reassembled. It takes time and effort.
In general, in an imaging apparatus, a cable extending from a circuit board is pulled out from the rear case. However, if the circuit board is attached to the front case as in Patent Document 1, it is difficult to route the cable when the rear case is attached. In addition, there is a risk that malfunctions and contact failures may occur due to stress applied to the cable.

Moreover, when adjusting the focus by interposing a spacer between the post provided on the front case and the circuit board as in Patent Document 1, it is necessary to insert the spacer into at least two posts. It is difficult to handle because it is a small spacer.
Furthermore, it is necessary to clamp the circuit board when adjusting the optical axis, but it is difficult to handle because the circuit board may be deformed by a load during clamping.
Therefore, an object of the present invention is to provide an imaging apparatus that can improve the assembly efficiency and can be easily maintained.

In order to solve the above problems, an imaging apparatus according to the present invention holds an imaging lens, an imaging element that captures a subject image formed by the imaging lens, a circuit board on which the imaging element is mounted, and the imaging lens. A first housing having a first opening and a second opening provided on the imaging side opposite to the first opening, and an opening corresponding to the second opening, A second housing for holding the circuit board; an annular spacer sandwiched between the second opening of the first housing and the opening of the second housing; and an inner peripheral side or an outer peripheral side of the spacer The elastic member is disposed between the first casing and the second casing together with the spacer, and the first casing and the second casing are fixed in a state where the spacer is sandwiched. Fixing means, and the spacer thickness or number of stacked layers The distance between the imaging lens and the imaging device and can be adjusted by changing the elastic member so as to seal the deformation close contact with a gap between said first housing and said second housing It is characterized by that.

  According to the present invention, since the lens is fixed to the first casing and the circuit board on which the imaging element is mounted is fixed to the second casing, the first casing and the second casing are By removing and opening the housing, the lens and the image sensor are exposed, and maintenance can be easily performed. In addition, since the circuit board is fixed to the second casing, the circuit board and the cable drawn out from the circuit board through the rear case can be combined into the second casing. In addition to avoiding wiring and connections and preventing problems and contact failures due to stress applied to the cable, it is possible to reduce the size of the imaging apparatus because no useless space is formed in the second housing. In addition, since the focus adjustment is performed by the annular spacer interposed between the first casing and the second casing, the number of spacers used can be minimized and larger than the one interposed in the post. This makes it easy to handle and improves assembly efficiency. Furthermore, since the optical axis can be adjusted by adjusting the positional relationship between the first housing and the second housing, there is no need to directly clamp the circuit board and there is no possibility of deformation of the circuit board. Handling becomes easy.

The elastic member further includes an elastic member disposed on the inner peripheral side or the outer peripheral side of the spacer and sandwiched between the first casing and the second casing together with the spacer. you seal the gap deformed contact between the housing and said second housing.
In this way, by sealing the gap between the first housing and the second housing with the elastic member, it is possible to provide a waterproof / drip-proof imaging device, particularly in-vehicle installed outdoors. It can be suitably used for cameras and surveillance cameras.

Further, the fixing means can finely adjust the relative position between the first casing and the second casing in a direction perpendicular to the optical axis of the imaging lens, and holds and fixes the finely adjusted state. It is good also as a structure.
Thus, the optical axis can be easily adjusted by adjusting the relative positions of the first housing and the second housing. At this time, compared with the conventional case where the circuit board is clamped and the optical axis is adjusted, the present configuration is easy to handle because the housing is clamped, and the first housing and the second housing are assembled. Since the optical axis can be adjusted later, it is also suitable for recorrecting the optical axis.

  Furthermore, it is preferable that the fixing means is fastening, bonding or welding with a screw, whereby the optical axis can be adjusted easily, and the first casing and the second casing after the optical axis adjustment. And can be securely fixed.

  According to the present invention, since the lens and the circuit board on which the imaging element is mounted are fixed to different housings, maintenance can be easily performed. In addition, since the circuit board is fixed to the second casing, it is possible to avoid unreasonable wiring and connection, and to prevent problems and contact failures due to stress applied to the cable. Furthermore, since the focus adjustment is performed by the annular spacer interposed between the first casing and the second casing, the assembly efficiency can be improved. Furthermore, since the optical axis can be adjusted by adjusting the relative positions of the first housing and the second housing, there is no need to directly clamp the circuit board and there is no possibility of deformation of the circuit board. Handling becomes easy.

It is a sectional side view which shows the imaging device which concerns on embodiment of this invention. 1 is an external side view showing an imaging apparatus according to an embodiment of the present invention. It is a perspective view which shows the internal structure of a front case. It is a perspective view which shows the internal structure of a rear case. (A) is a perspective view of an annular spacer, and (B) is a side view. It is an expanded sectional view which shows the fixing | fixed part of a front case and a rear case.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the shape of the component described in this example is not intended to limit the scope of the present invention, but is merely an illustrative example.

First, the overall configuration of an imaging apparatus according to an embodiment of the present invention will be described with reference to FIG. Here, FIG. 1 is a side sectional view showing an imaging apparatus according to an embodiment of the present invention.
An imaging apparatus 1 according to an embodiment of the present invention mainly includes an imaging lens 5, an imaging element 6 that images a subject image formed by the imaging lens 5, a circuit board 7 on which the imaging element 6 is mounted, The front case 2, the rear case 3, an annular spacer 10, and a fixing means 11 that fixes the front case 2 and the rear case 3. The front case 2 is a first casing in the present invention, and the rear case 3 is a second casing in the present invention.

  The front case 2 includes a first opening 21 that holds the imaging lens 5, and a second opening 22 that is provided on the imaging side so as to face the first opening 21. Only one imaging lens 5 may be held in the first opening 21, a plurality of imaging lenses 5 may be held in the optical axis direction, or a plurality of imaging lenses 5 may be held in the optical axis direction. A lens holder may be attached to the first opening 21. In any case, the imaging lens 5 is fixed to the front case 2 side, and is arranged so as to form an image on the imaging element 6 with light incident from the first opening 21.

The rear case 3 has an opening 31 corresponding to the second opening 22 of the front case 2. The rear case 3 has a plurality of posts 32 to which the circuit board 7 is attached. A screw hole 33 is formed in the post 32 in the axial direction, and the circuit board 6 is fixed to the post 32 by the board fixing screw 18. However, the fixing method of the post 32 and the circuit board 7 is not limited to screw fastening.
An imaging element 6 is mounted on the surface of the circuit board 7 on the imaging lens side. On the other hand, a cable 8 extends from the surface of the circuit board 7 opposite to the surface on which the image sensor 6 is mounted, and the cable 8 is drawn to the outside through the rear case 3.
The front case 2 and the rear case 3 are made of resin, for example.

  Thus, according to this embodiment, since the imaging lens 5 is fixed to the front case 2 and the circuit board 7 on which the imaging element 6 is mounted is fixed to the rear case 3, the front case 2 and the rear case 3 are connected. By removing the case and opening the case, the imaging lens 5 and the imaging element 6 are respectively exposed, and maintenance can be easily performed. Further, since the circuit board 7 is fixed to the rear case 3, the circuit board 7 and the cable 8 can be combined into the rear case 3, thereby avoiding unreasonable wiring and connection and causing problems and contact due to stress on the cable 8. Can prevent defects.

  Further, the front case 2 and the rear case 3 are fixed by the fixing means 11 with the second opening 22 and the opening 31 facing each other. The fixing means 11 has a configuration in which the optical axis can be adjusted by finely adjusting the relative position between the front case 2 and the rear case 3 in the direction perpendicular to the optical axis of the imaging lens 5. This optical axis adjustment method will be described later. As the fixing means 11, fastening with screws, adhesion or welding is preferably used. Thereby, the optical axis adjustment can be easily performed, and the front case 2 and the rear case 3 can be securely fixed after the optical axis adjustment.

  In the present embodiment, as an example, a case where a fastening screw is used for the fixing means 11 will be described. In this case, a screw hole 23 is formed in the front case 2, and a screw through hole 35 is formed in the rear case 3 corresponding to the screw hole 23. Then, the front case 2 and the rear case 3 are brought into contact with each other so that the fastening screw 11 passing through the screw through hole 35 is screwed into the screw hole 23 so that the front case 2 and the rear case 3 are fixed. It has become.

  FIG. 2 is an external side view showing the imaging apparatus 1 according to the embodiment of the present invention. As shown in the figure, it is preferable to provide a step at a portion where the screw through hole 35 is opened on the outer periphery of the rear case 3 so that the head 11 a of the fastening screw 11 does not protrude from the rear case 3.

  Returning to FIG. 1, an annular spacer 10 is interposed between the front case 2 and the rear case 3. The spacer 10 may be a resin or a metal, but preferably has a rigidity that does not cause deformation due to pressure by the fastening screw 11. This is to prevent the distance between the imaging lens 5 and the imaging element 6 adjusted by the spacer 10 from changing when the front case 2 and the rear case 3 are fixed.

FIG. 3 is a perspective view showing the internal structure of the front case. As shown in the figure, it is preferable to provide a stepped portion 24 over the entire inner periphery of the front case 2 and fit the annular spacer 10 into the stepped portion 24.
FIG. 4 is a perspective view showing the internal structure of the rear case. Also in the rear case 3, it is preferable to provide a stepped portion 36 similarly to the above-described front case 2 and to fit the annular spacer 10 into the stepped portion 36. Thereby, it can prevent that the position shifts after installing spacer 10. The height of the stepped portion 24 and the stepped portion 36 is set so that the sum of the stepped portions 24 and 36 is smaller than the thickness of the spacer 10.

FIG. 5A is a perspective view of an annular spacer, and FIG. 5B is a side view. As shown in the figure, it is preferable that the thickness can be adjusted by stacking a plurality of spacers 10A and 10B. The distance between the imaging lens 5 and the imaging element 6 can be adjusted (focus adjustment) by the number of stacked spacers 10.
In addition to the above-described focus adjustment methods, a plurality of types of spacers 10 having different thicknesses may be prepared, and a spacer 10 having an appropriate thickness may be selected to perform focus adjustment. Focus adjustment may be performed by stacking a plurality of types of spacers 10 in combination.

  As described above, since the focus adjustment is performed by the annular spacer 10 interposed between the front case 2 and the rear case 3, the number of the spacers 10 used can be minimized, and the spacer 10 can be used more than the one interposed in the post. Can be made large, making handling easier and improving assembly efficiency.

  Further, the spacer 10 is provided with step portions 101A, 102A, 101B, and 102B on the outer periphery and inner periphery thereof, and among the stacked spacers 10, the inner peripheral step portion 102A of the adjacent spacers 10A and 10B and the outer peripheral side It is preferable to configure so that the step portion 101B is fitted. Accordingly, the stacked spacers 10A and 10B can be reliably fixed without being displaced from each other.

Returning to FIG. 1, the imaging apparatus 1 of the present embodiment can be made waterproof / drip-proof structure by attaching the elastic member 12. The elastic member 12 is formed in an annular shape, is disposed on the inner peripheral side or the outer peripheral side of the spacer 10, and is sandwiched between the front case 2 and the rear case 3 together with the spacer 10. The cross-sectional shape of the elastic member 12 may be circular or rectangular.
FIG. 1 shows a case where the elastic member 12 is arranged on the outer peripheral side of the spacer 10 as an example. Further, the elastic member 12 is deformed and adhered between the front case 2 and the rear case 3 so as to seal a gap between the cases.

  In this way, by sealing the gap between the front case 2 and the rear case 3 with the elastic member 12, the imaging device 1 having a waterproof / drip-proof effect can be obtained. It can also be suitably used for surveillance cameras.

  Next, the optical axis adjustment will be described with reference to FIG. FIG. 6 is an enlarged cross-sectional view showing a fixed part of the front case 2 and the rear case 3. Here, the case where the fastening screw 11 is used as the fixing means is shown as an example. In this case, the diameter D1 of the screw hole 23 of the front case 2 is formed so as to coincide with the diameter of the fastening screw 11, and the diameter D2 of the screw through hole 35 of the rear case 3 is formed larger than the diameter of the fastening screw. That is, D1 <D2. At this time, the diameter D2 of the screw through hole 35 of the rear case 3 is naturally smaller than the head 11a of the fastening screw 11. The screw through hole 35 of the rear case 3 may not be provided with a female screw.

  When adjusting the optical axis, the spacers 10 are interposed between the front case 2 and the rear case 3 to clamp the respective cases, and the fastening screws 11 inserted through the screw through holes 35 of the rear case 3 are attached to the front case 2. The screw hole 23 is screwed. At this time, the screwing amount is adjusted so that the rear case 3 has a pressing force enough to move in the horizontal direction with respect to the optical axis P of the imaging lens 5. Then, the rear case 3 is finely adjusted in the horizontal direction with respect to the optical axis P so that the optical axis P of the imaging lens 5 is positioned at an appropriate position. When the optical axis adjustment is completed, the fastening screw 11 is further screwed and fixed so that the front case 2 and the rear case 3 are not displaced by the pressing force of the head portion 11a of the fastening screw 11.

  As described above, it is possible to easily adjust the optical axis by adjusting the relative position between the front case 2 and the rear case 3. At this time, as compared with the conventional case where the optical axis is adjusted by clamping the circuit board 7, the case is easy to handle because the case is clamped, and the optical axis is adjusted after the front case 2 and the rear case 3 are assembled. Therefore, it is also suitable for recorrecting the optical axis.

DESCRIPTION OF SYMBOLS 1 Imaging device 2 Front case 3 Rear case 5 Imaging lens 6 Imaging element 7 Circuit board 10 Spacer 11 Fixing means (fastening screw)
12 Elastic member 18 Substrate fixing screw 21 First opening 22 Second opening 24 Stepped portion 31 Opened 32 Post 36 Stepped portion

Claims (6)

An imaging lens;
An image sensor for imaging a subject image formed by the imaging lens;
A circuit board on which the image sensor is mounted;
A first housing having a first opening for holding the imaging lens, and a second opening provided on the image forming side opposite to the first opening;
A second housing having an opening corresponding to the second opening and holding the circuit board;
An annular spacer sandwiched between the second opening of the first housing and the opening of the second housing;
An elastic member disposed on the inner peripheral side or outer peripheral side of the spacer and sandwiched between the first casing and the second casing together with the spacer;
A fixing means for fixing the first casing and the second casing in a state of sandwiching the spacer;
The distance between the imaging lens and the imaging element can be adjusted by changing the thickness of the spacer or the number of stacked layers ,
The imaging apparatus according to claim 1, wherein the elastic member is deformed and adhered between the first casing and the second casing to seal the gap . The fixing means is configured to finely adjust a relative position between the first casing and the second casing in a direction perpendicular to the optical axis of the imaging lens, and to hold and fix the finely adjusted state. The imaging apparatus according to claim 1 , wherein: It said locking means, fastening by screws, an imaging apparatus according to claim 1 or 2, characterized in that an adhesive or welding. A step portion is formed over the entire inner circumference of each of the first casing and the second casing,
  The spacer is fitted in a first step portion formed over the entire circumference on the inner circumference side of the first casing, and over the entire circumference on the inner circumference side of the second casing. The imaging device according to claim 1, wherein the imaging device is fitted into the formed second step portion. The imaging apparatus according to claim 4, wherein a sum of heights of the first step portion and the second step portion is smaller than a thickness of the spacer. The spacer has an inner peripheral side stepped portion and an outer peripheral side stepped portion, and is configured so that the inner peripheral side stepped portion and the outer peripheral side stepped portion of adjacent spacers are fitted together when stacked. The imaging apparatus according to claim 1, wherein the imaging apparatus is an imaging apparatus.

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