JP4552580B2 - Image sensor unit - Google Patents

Description

  The present invention relates to an image sensor unit of a digital camera.

  The digital camera arranges an imaging lens and a solid-state imaging device (CCD) in the camera body, and controls light that is captured by the imaging lens and incident on the solid-state imaging device in front of the solid-state imaging device. A phase grating type optical low-pass filter is arranged.

  In this digital camera, it is necessary to set the distance between the solid-state image sensor and the low-pass filter in accordance with the performance of the solid-state image sensor and the imaging lens. If they are arranged individually, the structure is complicated and it is difficult to make the digital camera thinner.

Therefore, conventionally, an adhesive in which a spherical spacer is mixed on the front surface of the solid-state imaging device is applied in a frame shape surrounding the imaging area of the solid-state imaging device, and a low-pass filter is overlaid thereon, and the solid-state imaging device and the low-pass filter The distance between the solid-state imaging device and the low-pass filter is regulated by the spherical spacer and adhered by the adhesive, so that the solid-state imaging device and the low-pass filter can be combined into a digital camera as one imaging device unit. It is mounted (see Patent Document 1).
JP-A-6-58810

However, the conventional image sensor unit by means of an adhesive coated in a frame shape and a solid-state image pickup element and the optical filter, since the space between the solid-state image pickup element and the optical filter is sealed, the temperature change, There is a problem in that moisture in the air in the space is condensed on the opposing surfaces of the solid-state imaging device and the optical filter to cause fogging, which significantly reduces imaging performance.

In the present invention, a solid-state image pickup device and an optical filter are bonded together to form a single unit, but the opposition surface of the solid-state image pickup device and the optical filter due to temperature change is eliminated to always maintain good image pickup performance. An object of the present invention is to provide an imaging device unit that can be used.

The image sensor unit of the first aspect of the invention, a solid-state imaging device, an optical filter placed in front of the solid-made frame surrounding the imaging area of the solid-before Symbol solid-state imaging device It is arranged between the optical filter, the length from the inner periphery to the outer periphery of at least one of the application surface of the solid-state imaging device and the application surface of the optical filter, and the length direction of the frame side And a spacer frame having a plurality of ventilation grooves formed in a direction obliquely intersecting with each other, and the solid-state imaging device and the optical filter are bonded together via the spacer frame. .

An image sensor unit according to a second aspect of the present invention includes a solid-state image sensor, an optical filter disposed in front of the solid-state image sensor, and a frame surrounding an imaging area of the solid-state image sensor. Between the optical filter and at least one of the affixing surface of the solid-state imaging device and the affixing surface of the optical filter, the length extending from the inner periphery to the outer periphery, and in the length direction of the frame side On the other hand, a plurality of ventilation grooves are formed in a net shape along two directions, a direction obliquely intersecting one direction and a direction obliquely intersecting the other direction with respect to the length direction of the frame side. The solid-state imaging device and the optical filter are bonded together via the spacer frame.

An image sensor unit according to a third aspect of the present invention includes a solid-state image sensor, an optical filter disposed in front of the solid-state image sensor, and a frame surrounding an imaging area of the solid-state image sensor. A plurality of ventilation grooves having a length extending from the inner periphery to the outer periphery are formed on at least one of the attachment surface of the solid-state imaging device and the attachment surface of the optical filter. And a spacer frame provided with a foreign matter adhesion film, and the solid-state imaging device and the optical filter are bonded together via the spacer frame.

  When the spacer frame is a frame in which the ventilation groove is formed, the ventilation groove is preferably a narrow groove having a width and a depth of 10 μm or less.

The image sensor unit of the present invention is a solid image sensor and an optical filter that are bonded together via a spacer frame having air permeability that allows air to flow at least between the inner periphery and the outer periphery of the frame body. Therefore, although the solid-state imaging device and the optical filter are bonded together to form one unit, it is possible to always maintain good imaging performance by eliminating fogging of the opposing surfaces of the solid-state imaging device and the optical filter due to temperature change. it can.

  In this image sensor unit, it is desirable that the spacer frame has elasticity. By doing so, the image sensor unit can be provided with impact resistance.

In addition, the spacer frame having air permeability may be a foamed resin frame having open cells as long as it has air permeability between at least an inner periphery and an outer periphery thereof, and a solid image pickup device attachment surface and the optical filter. It may be a frame in which a plurality of ventilation grooves extending from the inner periphery to the outer periphery are formed on at least one of the pasting surfaces, and the space between the solid-state imaging device and the optical filter can be used regardless of which spacer frame is used. The temperature inside can be changed by following the temperature change outside the image sensor unit by the air flow inside the space and outside the image sensor unit.

When the spacer frame is a frame formed with the ventilation groove, the ventilation groove is preferably a narrow groove having a width and a depth of 10 μm or less. It is possible to prevent foreign matter from entering the space between the solid-state image sensor and the optical filter through the image sensor. Therefore, a shadow defect caused by entry of foreign matter from the outside is generated in the image captured by the solid-state image sensor. There is no.

The ventilation grooves are preferably formed at substantially equal pitches on each frame side of the spacer frame. By doing so, air in the space between the solid-state image sensor and the optical filter and the image sensor When the amount of mutual flow with the air outside the unit is further increased, and the fogging of the opposing surfaces of the solid-state imaging device and the optical filter due to temperature change can be further effectively eliminated, and the spacer frame has elasticity Can further improve the impact resistance of the image sensor unit.

  Further, the ventilation groove is preferably formed along a direction obliquely intersecting with the length direction of the frame side of the spacer frame, and in this way, the length of the ventilation groove is increased. Further, it is possible to more effectively prevent foreign substances from entering from the outside.

Further, the ventilation groove obliquely intersects one direction with respect to the length direction of the frame side of the spacer frame and obliquely intersects the other direction with respect to the length direction of the frame side. It is more preferable to form a net along the two directions. By doing so, it is possible to effectively prevent the entry of foreign matter from the outside, and the space between the solid-state imaging device and the optical filter. The amount of mutual flow between the air inside and the air outside the image sensor unit can be increased, and fogging of the opposing surfaces of the solid-state image sensor and the optical filter due to temperature change can be more effectively eliminated.

  In addition, when the spacer frame is a frame body in which the ventilation groove is formed, it is desirable to provide a foreign matter adhesion film on the surface of the ventilation groove, so that the entry of foreign matter from the outside can be more reliably performed. Can be prevented.

  1 to 4 show an embodiment of the present invention. FIG. 1 is an exploded perspective view of an image sensor unit, and FIG. 2 is a sectional view of the image sensor unit.

  As shown in FIGS. 1 and 2, the image sensor unit 1 includes a solid-state image sensor (CCD) 2, a phase grating optical low-pass filter 6 disposed in front of the solid-state image sensor 2, and the solid-state image sensor. A spacer frame 7 is provided between the element 2 and the low-pass filter 6.

  The solid-state imaging device 2 has a plurality of imaging pixels (not shown) arranged in a matrix on the front surface thereof, and the front surface of the solid-state imaging device 2, that is, the imaging surface, is a cover that protects the imaging surface. The glass 3 is affixed and the mounting plate 4 is attached to the rear surface. Note that both end portions of the mounting plate 4 protrude outwardly on both sides of the solid-state imaging device 2, and screw insertion holes 5 are provided in these protruding portions.

  The phase grating optical low-pass filter 6 has a plurality of low-pass filter elements (not shown) arranged in a matrix on one surface of a transparent glass plate.

  On the other hand, the spacer frame 7 is formed of a rectangular frame surrounding an imaging area 2a in which a plurality of imaging pixels of the solid-state imaging device 2 are arranged in a matrix, and the thickness between both surfaces is determined by the solid-state imaging. It is set according to the design distance between the imaging surface of the element 2 and the phase grating optical low pass filter 6.

  This spacer frame has air permeability at least between the inner periphery and the outer periphery of the frame body. The spacer frame 7 used in this embodiment is a frame body in which a plurality of ventilation grooves 8 each having a length extending from the inner peripheral edge to the outer peripheral edge are formed on both surfaces, and air is passed through the plurality of ventilation grooves 8. It has sex.

  In this embodiment, the spacer frame 7 is an elastic frame made of an elastic material such as silicon rubber.

  3 and 4 are a perspective view of the spacer frame 7 and an enlarged view of a part thereof. The ventilation groove 8 is a narrow groove having a width and depth of 10 μm or less, preferably 2 to 5 μm. Each frame side of the frame 7 is formed with a substantially equal pitch.

  Further, the plurality of ventilation grooves 8 are formed on both surfaces of the spacer frame 7 along a direction that obliquely intersects with the length direction of the frame side at an angle of 30 to 60 degrees, preferably 40 to 50 degrees. Are formed parallel to each other.

  Further, as shown in FIG. 4, a foreign substance adhesion film 9 made of a coating film of non-drying oil such as grease is extremely small, for example, about 0.5 μm on the groove surfaces of the plurality of ventilation grooves 8. It is provided in a thin thickness.

  The solid-state image sensor 2 and the phase grating optical low-pass filter 6 are bonded together via the spacer frame 7 as shown in FIG.

  In this embodiment, the front surface of the solid-state imaging device 2 (the front surface of the cover glass 3) and the filter surface of the low-pass filter 6 are respectively formed by the double-sided adhesive tapes 10a and 10b having substantially the same frame shape as the spacer frame 7. The spacer frame 7 is attached to one surface and the other surface.

  The image sensor unit 1 is mounted on a thin digital camera. For example, as shown in FIG. 2, the inner side of the casing 11 whose front surface indicated by a virtual line (two-dot chain line) in FIG. The low-pass filter 6 is directed to the opening, the mounting plate 4 on the rear surface of the solid-state imaging device 2 is screwed to the inner back surface of the casing 11, and the imaging lens is disposed on the front side in the casing 11. By inserting 12, a single imaging module is mounted in a camera body (not shown).

  Although the imaging lens 12 is simplified in FIG. 2, the imaging lens 12 has a fixed lens barrel and a movable lens barrel, protrudes from the front surface of the camera body during operation imaging, and is retracted when not in use. The image pickup device unit 1 is arranged with the low-pass filter 6 close to the rear end of the image pickup lens 12.

  Since the image sensor unit 1 is formed by bonding a solid-state image sensor 2 and a phase grating optical low-pass filter 6 through a spacer frame 7 having air permeability between an inner periphery and an outer periphery, Although the image pickup device 2 and the low-pass filter 6 are bonded to form one unit, the opposing surface of the solid-state image pickup device 2 and the low-pass filter 6 due to temperature change, that is, the front surface of the solid-state image pickup device 2 (the front surface of the cover glass 3). ) And the fogging of the rear surface of the low-pass filter 6 can be eliminated to always maintain good imaging performance.

  That is, in the conventional image sensor unit in which the solid-state image sensor and the low-pass filter are bonded with an adhesive applied in a frame shape, the space between the solid-state image sensor and the low-pass filter is sealed. Even when the temperature inside the camera body, that is, the temperature outside the image sensor unit rapidly rises like when a digital camera is brought indoors heated from the outside, the solid-state image sensor and the low-pass filter of the image sensor unit The temperature in the space between the two does not change immediately, so that there is a large difference between the temperature outside the image sensor unit and the temperature in the space of the image sensor unit, and moisture in the air in the space However, condensation occurs on the opposing surfaces of the solid-state imaging device and the low-pass filter, resulting in fogging, which significantly reduces imaging performance.

  On the other hand, the image pickup device unit 1 of the above embodiment has a breathable spacer in which the solid-state image pickup device 2 and the low-pass filter 6 are each formed with a plurality of ventilation grooves 8 each having a length extending from the inner periphery to the outer periphery. Since it is bonded through the frame 7, the temperature in the space between the solid-state image sensor 2 and the low-pass filter 6 of the image sensor unit 1 is such that the air in the space and the air outside the image sensor unit 1. To follow the temperature change outside the image sensor unit 1.

  Therefore, the image sensor unit 1 does not cause a large difference between the temperature outside the image sensor unit 1 and the temperature in the space. Therefore, for example, a digital camera is brought into a room heated from a low temperature outdoors in winter. Even at this time, good imaging performance can be maintained without causing fogging on the opposing surfaces of the solid-state imaging device 2 and the low-pass filter 6.

  Further, in the above embodiment, the spacer frame 7 is an elastic frame made of an elastic material such as silicon rubber. Therefore, even when an impact is applied during the mounting operation in the casing 11, for example, the impact is applied to the spacer. It can be absorbed by the frame 7, so that the image pickup device unit 1 can have impact resistance.

  Moreover, since the spacer frame 7 has elasticity, the image sensor unit 1 is provided with, for example, a screw mechanism that draws the low-pass filter 6 toward the solid-state image sensor 2 on the outside of the image sensor unit 1. The distance between the imaging surface of the solid-state imaging device 2 and the low-pass filter 6 can be finely adjusted by elastically deforming the spacer frame 7 in the thickness direction by the pulling force of the low-pass filter 6.

  Further, since the imaging element unit 1 has the width and depth of the ventilation grooves 8 on both surfaces of the spacer frame 7 set to 10 μm or less (preferably 2 to 5 μm), the inside of the ventilation groove 8 from outside the imaging element unit 1 is formed. It is possible to prevent foreign matter from entering the space between the solid-state image pickup device 2 and the low-pass filter 6, and thus cause a shadow defect due to the entry of foreign matter from the outside in the image picked up by the solid-state image pickup device 2. There is nothing.

  Further, since the imaging device unit 1 is formed with the ventilation grooves 8 at substantially equal pitches on each side of the spacer frame 7, the space between the solid-state imaging device 2 and the low-pass filter 6. The amount of mutual flow between the air inside and the air outside the image sensor unit 1 can be further increased, and the fogging of the opposing surfaces of the solid-state image sensor 2 and the low-pass filter 6 due to temperature change can be further effectively eliminated, and from the outside When an impact is applied, the impact force can be dispersed and absorbed in the portion between the ventilation grooves 8 of the spacer frame 7, so that the impact resistance of the image sensor unit 1 can be further improved. .

  Further, since the imaging element unit 1 is formed with the ventilation groove 8 along a direction obliquely intersecting with the length direction of the frame side of the spacer frame 7, the length of the ventilation groove 8 is increased. It is possible to more effectively prevent foreign substances from entering from the outside.

  Further, since the image pickup device unit 1 is provided with the foreign substance adhesion film 9 made of a non-drying oil and grease coating film such as grease on the ventilation groove surface of the spacer frame 7, extremely fine foreign substances are introduced into the ventilation frame from the outside. Even if it enters the groove 8, the foreign matter can be adsorbed by the foreign matter adhesion film 9, so that foreign matter can be prevented from entering from the outside more reliably.

  In addition, in the above embodiment, the front surface of the solid-state imaging device 2 (the front surface of the cover glass 3) and the filter surface of the low-pass filter 6 are respectively formed by the double-sided adhesive tapes 10a and 10b having substantially the same frame shape as the spacer frame 7. Since it is affixed to one side and the other side of the spacer frame 7, fine foreign matter that has entered the ventilation groove 8 from the outside is exposed in the ventilation groove 8 of the double-sided adhesive tape 10a, 10b. Even the portion can be adsorbed, and therefore, the entry of foreign matter from the outside can be more reliably prevented.

  In the above embodiment, a plurality of ventilation grooves 8 are formed on both surfaces of the spacer frame 7 in parallel with each other along a direction obliquely intersecting the length direction of the frame side. As in the other embodiment shown in FIG. 5, the ventilation groove 8 is formed in a direction obliquely intersecting one direction with respect to the length direction of the frame side of the spacer frame 7 and in the length direction of the frame side. On the other hand, it is more preferable to form a net-like shape along two directions obliquely intersecting the other direction. By doing so, it is possible to effectively prevent entry of foreign matters from the outside, and The amount of mutual circulation between the air in the space between the image sensor 2 and the low-pass filter 6 and the air outside the image sensor unit 1 is increased, and the clouding of the opposing surfaces of the solid-state image sensor 2 and the low-pass filter 6 due to temperature change is further increased. It can be effectively eliminated.

  Moreover, in the said Example, although the some ventilation groove | channel 8 is formed in both surfaces of the spacer frame 7, respectively, the said ventilation groove | channel 8 is either one of the bonding surface of the solid-state image sensor 2, and the bonding surface of the low-pass filter 6. It may be formed only on the surface.

  Further, in the above embodiment, the spacer frame 7 is provided on the affixing surface of the solid-state imaging device 2 and the affixing surface of the low-pass filter 6 (or at least one of the surfaces), and a plurality of ventilation holes having a length extending from the inner periphery to the outer periphery. Although the frame body is formed with the grooves 8, the spacer frame disposed between the solid-state imaging device 2 and the low-pass filter 6 may be a frame body made of foamed resin such as foamed polystyrene or foamed polyurethane having open cells, Even if this spacer frame is used, the temperature in the space between the solid-state image sensor 2 and the low-pass filter 6 is caused to follow the temperature change outside the image sensor unit 1 by the air flow between the space and the image sensor unit 1. Thus, it is possible to eliminate the fogging of the opposing surfaces of the solid-state imaging device 2 and the low-pass filter 6 due to temperature changes, and always maintain good imaging performance.

1 is an exploded perspective view of an image sensor unit showing an embodiment of the present invention. Sectional drawing of the said image pick-up element unit. The expansion perspective view of the spacer frame of the image sensor unit. FIG. 4 is an enlarged view of a part of FIG. 3. The perspective view of the spacer frame of the image sensor unit which shows other examples of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Image sensor unit, 2 ... Solid-state image sensor, 2a ... Imaging area, 3 ... Cover glass, 4 ... Mounting plate, 6 ... Phase grating type | mold optical low-pass filter, 7 ... Spacer frame, 8 ... Ventilation groove, 9 ... Foreign material Adhesion film, 10a, 10b ... double-sided adhesive tape, 11 ... casing, 12 ... imaging lens.

Claims (4)

A solid-state image sensor;
An optical filter disposed in front of the solid-state image sensor;
The solid consists frame surrounding the imaging area of the imaging element, is arranged between the front Stories solid-state imaging element and said optical filter, at least one of the joining surfaces of the joining surface and the optical filter of the solid-state image capturing device, that A spacer frame having a length extending from the inner peripheral edge to the outer peripheral edge and formed with a plurality of ventilation grooves along a direction obliquely intersecting the length direction of the frame side;
An image sensor unit, wherein the solid-state image sensor and the optical filter are bonded together via the spacer frame. A solid-state image sensor;
An optical filter disposed in front of the solid-state image sensor;
The solid consists frame surrounding the imaging area of the imaging element, is arranged between the front Stories solid-state imaging element and said optical filter, at least one of the joining surfaces of the joining surface and the optical filter of the solid-state image capturing device, that A length extending from the inner peripheral edge to the outer peripheral edge and obliquely intersecting one direction with respect to the length direction of the frame side, and obliquely extending in the other direction with respect to the length direction of the frame side A spacer frame having a plurality of ventilation grooves formed in a net shape along two directions of intersecting directions ,
An image sensor unit, wherein the solid-state image sensor and the optical filter are bonded together via the spacer frame. A solid-state image sensor;
An optical filter disposed in front of the solid-state image sensor;
The solid consists frame surrounding the imaging area of the imaging element, is arranged between the front Stories solid-state imaging element and said optical filter, at least one of the joining surfaces of the joining surface and the optical filter of the solid-state image capturing device, that A plurality of ventilation grooves having a length extending from the inner peripheral edge to the outer peripheral edge, and a spacer frame provided with a foreign substance adhesion film on the ventilation groove surface ;
An image sensor unit, wherein the solid-state image sensor and the optical filter are bonded together via the spacer frame. Said vent groove, image sensor unit according to any one of claims 1 to 3, wherein the width and depth are less narrow groove 10 [mu] m.

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