JP2001275023A - Image pickup element dustproof structure for video camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To interpose an elastic dustproof member, which has a small spring constant and good contactness and generates neither a flare nor ghost due to internal reflection, between an optical filter and an image pickup element. SOLUTION: An object image picked up by an image pickup element is formed on an image pickup element 13 through an optical filter 10 and an elastic dustproof member 11 is interposed between the optical filter 10 and image pickup element 13 to constitute the image pickup dustproof structure of the video camera. The dustproof member 11 has an opening part 12 for forming the subject image passed through the optical filter 10 on the image pickup element 13 and is provided with a slanting surface 12a which slants inward above a specific angle to a line parallel to the optical axis on the optical filter side of the opening part 12; even if incident light passed through the optical filter is reflected by the slanting surface 12a, the reflected light does not impinges on the image pickup element 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dustproof structure for an image pickup device of a video camera in which an elastic dustproof member is interposed between an optical filter and an image pickup device. Provide an inclined surface inclined inward at a predetermined angle or more with respect to a line parallel to the optical axis, so that even if incident light passing through the optical filter is reflected on the inclined surface, the reflected light does not enter the image sensor. In addition, the contact pressure on the image sensor side of the dustproof member is located inside the contact pressure on the optical filter side, so that the spring constant during compression of the dustproof member is reduced and the adhesion of the video camera is improved. The present invention relates to an image pickup device dustproof structure.

[0002]

2. Description of the Related Art In general, a video camera uses a CCD as an object image picked up by an image pickup lens through an optical filter.
An image is formed on an image sensor such as a (solid-state image sensor), and the subject image is photoelectrically converted by the image sensor. In order to prevent dust from entering between the optical filter and the CCD, a dustproof rubber is provided.

[0003] Dustproof rubber usually uses silicon rubber as a material, and its characteristic is that it does not change with time, but it has a drawback that dust easily adheres. If dust adheres to the dust-proof rubber, the attached dust moves inward because of a member used on the optical path, and enters the optical path to cause a problem of being picked up by the CCD. Therefore, it is desirable that the dust-proof rubber has a shape that is easy to clean in order to remove dust, for example, has a small number of irregularities or a shape having no concave groove with a right angle of corner.

FIG. 12 is a side sectional view of a front panel portion of a video camera provided with such a dustproof rubber. On the front panel 27, a cylindrical portion 27a is projected forward, and a screw for mounting a lens is engraved on the inner periphery of the cylindrical portion 27a. For example, a lens mount 28 for mounting a C-mount type lens is provided. Is formed.

A rectangular hole is formed in the rear end surface of the cylindrical portion 27a of the front panel 27. A filter bracket 30 having a rectangular hole is provided around the rectangular hole with screws 31,
It is screwed and fixed by 31. An optical filter 32 is fitted on the back surface of the filter bracket 30, the front surface of a dust-proof rubber 33 abuts on the peripheral portion of the optical filter 32, and the glass of a CCD (solid-state image sensor) device 35 is placed on the rear peripheral portion of the dust-proof rubber 33. The portion 35a comes into contact. Further, the CCD device 35 is fixed to the front panel 27 with a screw (not shown) via a CCD bracket, and the CCD substrate 36 is fixed to the front panel 27.

[0006]

By the way, in the above-described video camera, in order to make the dust-proof rubber 33 easy to clean, the rectangular hole of the dust-proof rubber 33 is gradually reduced toward the CCD device 35 side. An inclined surface 33a is provided. For this reason, as shown in FIG. 12, there is a possibility that intense light incident through a lens (not shown) is reflected by the inclined surface 33a and enters the element portion 35b of the CCD device 35. As described above, when strong light is reflected by the dust-proof rubber 33 and the reflected light is incident on the element portion 35b of the CCD device 35,
There were problems such as flare and ghosting.

Further, when the dust-proof rubber 33 is strongly pressed against the glass portion 35a of the CCD device 35 in order to prevent dust and dirt from entering the optical path, the thin glass portion 35a may be broken.

FIGS. 13A and 13B are diagrams showing a second example of a conventional dustproof rubber, in which FIG. 13A is a front view thereof, and FIG. The dustproof rubber 38 has the optical filter 3 on one side.
9 is fitted, and the other side is in contact with the glass part of the CCD device. However, the projection 38a of the dustproof rubber 38 on the CCD device side and the optical filter 3
Since the contact portion 38b contacting the outer peripheral portion of No. 9 is located in the optical path, there is a problem that a dust adhesion area is large.

FIGS. 14A and 14B are views showing a third example of a conventional dustproof rubber, in which FIG. 14A is a front view thereof, and FIG. 14B is a sectional view thereof taken along line DD. If the contact area between the dust-proof rubber and the glass part of the optical filter or the CCD device is large, the contact pressure is reduced, and the dust easily enters the dust-proof rubber. On the other hand, if the spring constant at the time of compression of the dustproof rubber is increased, the glass part of the CCD device is easily broken. Therefore, FIG.
The dust-proof rubber 40 shown in FIG. 4 is used to increase the contact pressure when compressing the rubber.
Although the protrusions 40a and the recesses 40b are formed in the contact portions, there is a problem that the cleaning workability is poor because the unevenness increases, and it is particularly difficult to remove dust in the recesses.

In view of the above, the present invention provides an elastic dustproof member interposed between an optical filter and an image pickup element so that the spring constant is small, the adhesion is good, and flare or ghost is not generated due to internal reflection. It is an object of the present invention to provide a dustproof structure for an image sensor of a video camera.

[0011]

According to the present invention, there is provided an image pickup device dustproof structure for a video camera, wherein an object image picked up by an image pickup lens is formed on an image pickup device through an optical filter, and the optical filter and the image pickup device are connected to each other. In a dustproof structure of a video camera in which a dustproof member having elasticity is interposed therebetween, the dustproof member has an opening for forming an image of a subject that has passed through the optical filter on the image pickup device, On the optical filter side of the opening, an inclined surface that is inclined inwardly by a predetermined angle or more with respect to a line parallel to the optical axis is provided. Light is not incident on the image sensor.

In the dustproof structure of the image pickup device of the video camera according to the present invention, even if incident light passing through the optical filter is reflected by the inclined surface provided on the optical filter side of the opening of the dustproof member, the inclined surface has a predetermined angle. Since the light is inclined inward as described above, the reflected light does not enter the image sensor. As a result, it is possible to prevent flare and ghost from occurring during shooting.

Further, the dust-proof structure of an image pickup device of a video camera according to the present invention forms an object image picked up by an image pickup lens on an image pickup device via an optical filter, and provides elasticity between the optical filter and the image pickup device. In a dustproof structure of an image pickup device of a video camera having a dustproof member provided therein, a contact pressure portion on the image pickup device side of the dustproof member is disposed inside a contact pressure portion on the optical filter side. It is.

In the dustproof structure of the image pickup device of the video camera according to the present invention, the contact pressure portion on the image pickup device side of the dustproof member is located inside the contact pressure portion on the optical filter side. The contact pressure point on the side rises all around. Thereby, the dust-proof member can be pressed against the optical filter and the imaging element with a small spring constant, and the adhesion can be improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of an embodiment of a dustproof structure of an image pickup device of a video camera according to the present invention will be described with reference to the drawings. FIG. 2 is an external view of a video camera to which the dust-proof structure of the imaging device of the video camera according to the present invention is applied. The video camera 1 has a front panel 2 and a rear panel 3
And a top panel 5. The front panel 2 is integrated with the bottom panel and has an L-shape when viewed from the side, and a cylindrical portion 2a protrudes forward from the front. The cylindrical portion 2a is open at the front, and a screw for attaching a lens is engraved on the inner periphery thereof to form a lens mount 6. Here, for example, a lens mount 6 for mounting a lens having a U1 screw as a mounting mechanism, that is, a so-called C-mount type lens is formed.

FIG. 1 is an exploded perspective view of an image pickup device dustproof structure of a video camera according to the present invention. A rectangular hole 2b is formed in the rear end surface of the cylindrical portion 2a of the front panel 2, and screw grooves 2c, 2c for screwing with a screw 8 described later are provided above and below the peripheral portion of the rectangular hole 2b. I have. Front panel 2
A filter bracket 7 having a rectangular hole 7a is in contact with the rear end face of the cylindrical portion 2a. Holes 7b, 7b for inserting the screw portion of the screw 8 are formed on the upper and lower sides of the rectangular hole 7a of the filter bracket 7. The screw portion of the screw 8 is inserted into the hole 7b of the filter bracket 7, and the tip is screwed into the screw groove 2c, so that the filter bracket 7 is screwed and fixed to the rear end surface of the cylindrical portion 2a of the front panel 2. ing.

An optical filter 10 is fitted on the back surface of the filter bracket 7 so as to cover the rectangular hole 7a. The optical filter 10 is in contact with a dustproof rubber 11 made of, for example, silicon rubber, which is an elastic dustproof member having a rectangular hole 12 as an opening so as to press down the periphery of the optical filter 10. A CCD, which is an image sensor, is provided around the rectangular hole 12 of the dustproof rubber 11.
(Solid-state imaging device) The glass portion 13a of the device 13 is in contact with the device. The CCD device 13 is roughly composed of a glass portion 13a, an element portion 13b described later, and a CCD bracket 13c.

At the upper end of the CCD substrate 14, the CCD substrate 14
A pair of left and right holes 14a, 14a for inserting a screw portion of a screw 16 for attaching the front panel 2 to the front panel 2 is formed. At the center of the CCD substrate 9, a CCD bracket 13 is provided.
A pair of left and right cutouts 14b, 14b for inserting a screw 17 for attaching the c to the front panel 2 are provided, and holes 13c-1, 13c of the CCD bracket 13c of the CCD device 13 are provided in front of the cutouts 14b, 14b, respectively.
-1 is located. The details of the filter bracket 7 and the dustproof rubber 11 will be described later.

According to the present invention, a rectangular hole 1 in a dustproof rubber 11 interposed between an optical filter 10 and a CCD device 13 is provided.
2, an inclined surface 12a that is inclined inward at a predetermined angle or more with respect to a line parallel to the optical axis on the optical filter 10 side;
Even if the incident light that has passed through the optical filter 10 is reflected by the inclined surface 12a, the reflected light is prevented from being incident on the element portion 13b of the CCD device 13, thereby preventing the occurrence of flare and ghost and preventing dust. Rubber 11 C
The optical filter 10 is pressed against the CD device 13.
So that the dustproof rubber 11
Even if the spring constant is small, the adhesion is good and the ingress of dust can be reliably prevented.

FIG. 3 is a perspective view of the front panel 2 as viewed from the back side. As shown in FIGS. 3 and 1, a filter bracket 7 having a rectangular hole 7 a is fixed to a rear end surface of the cylindrical portion 2 a of the front panel 2 by screws 8. An optical filter 10 is fitted on the back surface of the filter bracket 7, and the optical filter 10 has a rectangular hole 12.
The open dustproof rubber 11 is in contact.

A peripheral edge 2d for engaging with the peripheral edge of the top panel 5 is formed on the peripheral edge of the rear surface of the front panel 2 in a U-shape with an open bottom. Further, a bracket 2e having a screw hole for screwing with a screw 19 for attaching the top panel 5 is provided on the upper rear surface of the front panel 2.
A pair of bosses 2f having screw holes for screwing with screws 16 for attaching the CCD substrate 14 are provided on both sides of the bracket 2e so as to project inward. An engagement projection 2 for engaging with a notch 11b, which will be described later, of the dustproof rubber 11 is provided below the boss 2f on the left side of the rear surface of the front panel 2 when viewed from the rear.
j is protruded.

A boss 2g having a screw hole to be screwed with a screw 17 for attaching the CCD bracket 13c is provided on the right and left sides of the center of the rear surface of the front panel 2 in a protruding manner. In the center of the bottom of the front panel 2 is a CCD substrate 1
A positioning projection 2h for positioning the projection 4 projects rearward. Further, a pair of left and right mounting holes 2i, 2i through which a screw portion of a screw 20 for mounting the rear panel 3 is inserted is formed at the rear end of the bottom surface of the front panel 2.

FIG. 4 shows the filter bracket 7, and FIG. 4A is a front view showing the lens mount 6 side.
(B) is a rear view on the optical filter 10 side. An inclined portion 7a-1 is formed on the peripheral edge of the rectangular hole 7a of the filter bracket 7 on the front side. At the periphery of the rectangular hole 7a on the rear surface of the filter bracket 7, a substantially rectangular projection 7c for projecting the optical filter 10 is provided in a protruding manner. Notches 7c-1 are formed in the upper, lower, left, and right portions of the projection 7c, respectively. This notch 7c-1
Are for fitting with the protrusions 11a of the dustproof rubber 11, which will be described later. That is, the notch 7c-1 of the projection 7c of the filter bracket 7 is
Are fitted so that a rectangle without a missing portion is formed.

FIG. 5 is a front view of the dustproof rubber 11, and FIG.
7 is a sectional view taken along line AA of FIG. 5, and FIG. 7 is a sectional view taken along line BB of FIG. As shown in FIGS. 5 to 7, the dustproof rubber 11 has a rectangular hole 12 which is an opening at the center, and a projection 11 a is provided at the upper and lower ends and at the center near the left and right ends. Is provided with a notch 11b serving as a reference for positioning for engagement with the engagement projection 2j of the front panel 2. At the periphery of the rectangular hole 12 of the dustproof rubber 11 on the side of the optical filter 10, there is provided an inclined surface 12 a which is inclined inward so as to become gradually smaller toward the rear, and goes rearward on the periphery of the CCD device 13. A second inclined surface 12b inclined outward is provided so as to gradually increase in size. Then, as shown in FIG.
Is formed such that the inclination angle α of the rectangular hole 12 with respect to a line parallel to the optical axis of the first inclined surface 12a is larger than the inclination angle β with respect to a line parallel to the optical axis of the second inclined surface 12b. Have been. Here, for example, the inclination angle α is 45 ° and the inclination angle β is 15 °. Details of the inclination angle α will be described later.

FIG. 8 shows the CCD device 1 of the dustproof rubber 11.
It is a back view which is a 3rd surface. A projection 11c is formed on the surface of the dustproof rubber 11 on the CCD device 13 side over the entire circumference of the second inclined surface 12b, and the outer side surface of the projection 11c is also an inclined surface. The protrusion 11c of the dustproof rubber 11 is C
This is for contacting the glass part 13a of the CD device 13.

FIGS. 9 and 10 are views for explaining the mechanism of the shape change that occurs when the dust-proof rubber 11 incorporates the CCD device 13. FIG. As shown in FIG. 9, when the glass portion 13a of the CCD device 13 is brought into contact with the dustproof rubber 11, the projection 11c of the dustproof rubber 11 is moved to the CCD device 1.
No. 3 glass part 13a. Then, the screw portion of the screw 17 is inserted into the hole 13c-1 of the CCD bracket 13c of the CCD device 13 (see FIG. 1), and the screw 17 is tightened so that the CCD device 13 starts to move to the optical filter 10 side, and the protrusion is generated. The part 11c first collapses.

Further, by tightening the screw 17,
Since the contact pressure point R on the CCD device 13 side (the middle point of the protruding portion 11c) is located inside the contact pressure point F on the optical filter 10 side by δ, as shown in FIG. 12a is tilted toward the optical filter 10, and the pressure due to the displacement concentrates on the contact pressure point F on the optical filter 10 side. Thereby, the contact pressure point F portion, which is the smaller dimension of the contact pressure portion dimension L of the dustproof rubber 11 on the optical filter 10 side, protrudes over the entire circumference, so that the contact pressure on the optical filter 10 side is improved. Optical filter 10 of dustproof rubber 11
And the contact pressure point R of the dustproof rubber 11 on the side of the CCD device 13 is compressed over the entire circumference.
The contact pressure on the side also increases. For this reason, the spring constant at the time of compression of the dustproof rubber 11 can be reduced, and at the time of compression, the contact pressure point F on the optical filter 10 side rises over the entire circumference,
In addition, since the contact pressure point R on the CCD device 13 side is compressed over the entire circumference, the adhesion can be improved.

Therefore, the contact pressure point R of the dustproof rubber 11 on the CCD device 13 side is changed to the contact pressure point F of the optical filter 10 side.
The CCD device 13 is pressed against the dust-proof rubber 11 so that the contact pressure point F of the dust-proof rubber 11 on the optical filter 10 side is increased.
Is raised over the entire circumference, and the CC of the dustproof rubber 11 is
Since the contact pressure point R on the side of the D device 13 is compressed over the entire circumference, the optical filter 10 of the dustproof rubber 11 and the CCD
Contact pressure to device 13, optical filter 10 and C
The adhesion to the CD device 13 is improved, and the dustproof rubber 11 is improved.
It is possible to reliably prevent dust from entering the inside of the vehicle.

Also, because of the offset shape, the dust-proof rubber 1
1, the spring constant of the compression can be reduced, and the dimensional variation between the CCD device 13 and the optical filter 10 can be absorbed in mass production. In addition, the variation in the compressive force is suppressed, and the stress on the glass surfaces of both the CCD device 13 and the optical filter 10 can be reduced.

Furthermore, there is no concave shape in the optical path of the dustproof rubber 11, and the first inclined surface 12a and the second inclined surface
, And has a shape that is easy to clean and hardly leaves dust, so that the dust cleaning property can be improved and the dust-proof rubber 1 can be improved.
Since the dust adhering area is small in the first optical path, the adhering of dust can be suppressed.

FIG. 11 is a view for explaining the reflection of light when photographing high-intensity light. For example, even if high-luminance light is incident on the first inclined surface 12a of the dustproof rubber 11 substantially parallel to the optical axis via a lens (not shown), the first inclined surface 12a is parallel to the optical axis. Since it is inclined 45 ° inward with respect to the line,
The light is reflected by the first inclined surface 12a at a substantially right angle, and then reflected by the first inclined surface 12a on the opposite side.
The reflected light can be prevented from entering the element section 13b of the D device 13. Here, the first inclined surface 12a
Is inclined 45 ° to a line parallel to the optical axis,
If the angle is approximately 45 ° or more, it is possible to prevent reflected light from being incident on the element section 13b of the CCD device 13.

Therefore, since the first inclined surface 12a on the optical filter 10 side, which is the incident side of the dustproof rubber 11, is inclined 45 ° inward with respect to a line parallel to the optical axis, high-intensity light is emitted from the first When reflected on the inclined surface 12a, the reflected light can be prevented from being incident on the element portion 13b of the CCD device 13, whereby the flare or ghost phenomenon at the time of photographing can be reliably prevented.

In the above embodiment, the dustproof rubber 11
First inclined surface 1 on the optical filter 10 side which is the incident side of
2a is inclined 45 ° inward with respect to a line parallel to the optical axis. However, the present invention is not limited to this. At approximately 45 ° or more, high-intensity light is reflected on the first inclined surface 12a. Needless to say, the angle may be such that the reflected light does not enter the element portion 13b of the CCD device 13.

Although the dustproof rubber 11 is made of silicon rubber, it is not limited to this, and another rubber member may be used. Although the image pickup device dustproof structure is applied to a single-panel video camera, the invention is not limited thereto, and may be applied to a three-panel video camera.
Although the front panel 2 is integrated with the bottom panel, the present invention is not limited to this, and the front panel and the bottom panel may be provided separately.

[0035]

As described above, according to the present invention,
Even if incident light that has passed through the optical filter is reflected by the inclined surface provided on the optical filter side of the opening of the dustproof member, the reflected light is imaged because the inclined surface is inclined inward by a predetermined angle or more. The light does not enter the element, and flare and ghost can be reliably prevented from occurring during photographing.

The dustproof member does not have a concave shape in the optical path, but has only a convex shape at the center, and has a shape that is easy to clean and hardly causes dust to be left. Since the dust adhesion area is small in the optical path of the member, the adhesion of dust can be suppressed.

Further, since the contact pressure portion on the image sensor side of the dustproof member is arranged inside the contact pressure portion on the optical filter side, the contact pressure portion on the optical filter rises over the entire circumference when the dustproof member is compressed. Thereby, the dust-proof member can be pressed against the optical filter and the imaging element with a small spring constant, and the adhesion can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a dustproof structure of an image sensor of a video camera according to the present invention.

FIG. 2 is an external view of a video camera to which an image pickup device dustproof structure of the video camera according to the present invention is applied.

FIG. 3 is a perspective view of the front panel viewed from the back side.

4A and 4B show a filter bracket, wherein FIG. 4A is a front view and FIG. 4B is a rear view.

FIG. 5 is a front view of the dustproof rubber.

FIG. 6 is a sectional view taken along line AA of FIG. 5;

FIG. 7 is a sectional view taken along line BB of FIG. 5;

FIG. 8 is a rear view of the dustproof rubber.

FIG. 9 is a side sectional view showing a state where a glass part of the CCD device is in contact with dustproof rubber.

FIG. 10 is a side sectional view showing a state in which a glass part of a CCD device is pressed against dustproof rubber.

FIG. 11 is a diagram illustrating light reflection during high-brightness light imaging.

FIG. 12 is a side sectional view showing a dustproof structure of an image pickup device of a conventional video camera.

FIG. 13 is a view showing a second example of a conventional dustproof rubber.

FIG. 14 is a view showing a third example of a conventional dustproof rubber.

[Explanation of symbols]

1. Video camera 2. Front panel 3.
..Rear panel, 5 ... Top panel, 6 ... Lens mount, 7 ... Filter bracket, 10 ...
・ Optical filter, 11 ・ ・ ・ Dustproof rubber (dustproof member),
11a: protrusion, 12: rectangular hole (opening), 1
2a: first inclined surface (inclined surface), 12b: second
Inclined surface, 13 ... CCD device (imaging device),
13a: glass part, 13b: element part, 13c
..CCD bracket, 14 ... CCD board, R ..
-Contact pressure point on CCD device (imaging device) side, F ...
Contact pressure point on optical filter side

Claims (5)

[Claims] 1. An image pickup device for a video camera in which an object image picked up by an image pickup lens is formed on an image pickup device via an optical filter, and an elastic dustproof member is interposed between the optical filter and the image pickup device. In the structure, the dustproof member has an opening for forming an image of a subject that has passed through the optical filter on the image sensor, and the opening is provided on an optical filter side of the opening with respect to a line parallel to an optical axis. A video camera, characterized in that even if an incident light passing through the optical filter is reflected on the inclined surface, the reflected light is not incident on the image pickup device. Element dustproof structure. 2. The dustproof structure according to claim 1, wherein the predetermined angle is approximately 45 degrees. 3. The image pickup device of a video camera according to claim 1, wherein a second inclined surface inclined outward is provided on the image pickup device side of the opening of the dustproof member. Dust proof structure. 4. An image pickup device for a video camera, wherein an image of a subject taken by an image pickup lens is formed on an image pickup device via an optical filter, and an elastic dustproof member is interposed between the optical filter and the image pickup device. In the structure, a contact pressure portion on the image sensor side of the dustproof member is disposed inside a contact pressure portion on the optical filter side. 5. The dustproof structure according to claim 4, wherein, when the dustproof member is compressed, a contact pressure portion on the optical filter side protrudes all around.