JP2001268420A - Image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cool an image pickup element without enlarging device constitution or raising the cost and to perform long time exposure like celestial photographing. SOLUTION: In an electronic camera for image-forming an object image obtained through a lens 21 on the light receiving surface of the image pickup element 22 and picking up the image of the object by the image pickup element 22, by providing a pocket 12 for feeding a coolant near the back surface of the image pickup element 22 and feeding dry ice into the pocket 12, the celestial photographing is performed under the condition of less dark current.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus using an image pickup device such as a CCD, and more particularly to an image pickup device having a function of cooling the image pickup device for long-time photographing.

[0002]

2. Description of the Related Art In an electronic camera (digital still camera) using an image pickup device such as a CCD, it is necessary to perform long-time exposure in order to photograph a subject having extremely low luminance, such as astronomical photography. For long-time exposure, it is most important to reduce the dark current, and the image sensor must be cooled for the purpose of reducing the dark current. As a technique for cooling an imaging device in an electronic camera, it is known to use an electronic cooling device such as a Peltier device (Japanese Patent Laid-Open No. 7-38).
019 publication).

[0003] However, this type of apparatus has the following problems. That is, since an electronic cooling element such as a Peltier element is used, it is necessary to consume relatively large power and to radiate heat generated by the cooling element. For this reason, there has been a problem that the apparatus is totally dedicated exclusively, the apparatus configuration becomes large, and the manufacturing cost increases. Further, it is inconvenient to carry such an electronic camera on a daily basis.

[0004]

As described above, conventionally, in the cooling imaging technique of the image pickup apparatus, since an electronic cooling element such as a Peltier element is generally used, it is necessary to consume electric power and dissipate heat generated by the cooling element. As a result, there is a problem that the size of the apparatus is increased and the cost is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to cool an imaging device without increasing the size and cost of the apparatus.
An object of the present invention is to provide an imaging device capable of long-time exposure such as astronomical photography.

[0006]

(Structure) In order to solve the above problem, the present invention employs the following structure.

That is, the present invention relates to an imaging apparatus for forming a subject image obtained through a lens on a light receiving surface of an image pickup device and picking up an image of a subject with the image pickup device, wherein a cooling agent is provided near the image pickup device. A charging pocket or a mounting pocket to which a coolant unit can be mounted is provided.

The present invention also relates to a coolant unit for cooling an image pickup device of an image pickup device provided with an image pickup device for photographing a subject image, wherein the pocket unit is provided near the image pickup device of the image pickup device. It is characterized by being detachably attached to the.

Here, preferred embodiments of the present invention include the following. (1) The pocket is located on the back side of the image sensor and has a room-like structure having a lid, and the lid continuously forms an exterior surface of an apparatus housing containing the image sensor and the lens. That. (2) The back side of the image sensor is in direct contact with the wall surface of the room-like structure constituting the pocket or via a good heat conductor.

(3) An opening is provided in a circuit board on which the image pickup device is mounted so that the image pickup device is brought into contact with the wall surface of the room-like structure directly or through a good heat conductor. Mounted so that the back side protrudes from the opening. (4) Coolant shall be dry ice.

(Operation) According to the present invention, an inexpensive coolant such as dry ice, which is easily available, is charged or mounted in a pocket provided in the main body of the image pickup apparatus, so that dark current in the image pickup element is reduced. Can be made extremely small, and long-time exposure required for astronomical photography or the like can be performed. In this case, since the imaging device can be easily cooled without using a Peltier device or the like, it is possible to suppress an increase in the size and cost of the device configuration. That is,
In normal times, the camera can be carried around as a general camera on a daily basis, and cooling imaging can be temporarily performed as needed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
1A is a view for explaining a basic configuration of an electronic camera according to the embodiment, FIG. 1A is a horizontal sectional view seen from above, and FIG.
Is a rear view.

In the figure, reference numeral 10 denotes a camera housing, in which a lens 21, an image pickup device 22, a circuit board 23,
And various components (not shown) are accommodated. Lens 21
Is the outermost lens and one surface is exposed to the outside. Further, a focusing lens and a zoom lens (not shown) are arranged between the lens 21 and the image sensor 22. The image sensor 22 is, for example, a CCD image sensor, and is mounted on a circuit board 23.

Although the basic configuration up to this point is the same as that of a conventional general electronic camera, in the present embodiment, in addition to this, a coolant supply port for supplying a coolant is provided on the back side 11 of the camera housing 10. Pocket 12 is provided. The pocket 12 is located on the back side of the image sensor 22 and has a lid 13.
, And the lid 13 continuously forms the exterior surface of the camera housing 10. A part of the wall surface of the pocket 13 is
Is in direct contact with

In FIG. 1, reference numeral 14 denotes a lock mechanism for locking the lid 13 to the camera housing 10, and reference numeral 24 denotes the image pickup device 2.
2, a cover glass provided on the light receiving surface side, and 25 indicates a lead wire.

In such a configuration, when nothing is put in the pocket 12, it can be used as a normal electronic camera. On the other hand, by introducing a coolant such as dry ice into the pocket 12,
2 can be efficiently cooled, and imaging can be performed with little dark current. As a result, it is possible to photograph an extremely low-luminance subject such as an astronomical photograph that requires long-time exposure.

Therefore, according to the present embodiment, as compared with a conventional apparatus using a cooling mechanism such as a Peltier element for cooling an image pickup element, the configuration of the apparatus can be reduced, and the manufacturing cost can be significantly reduced. Can be. In addition, the camera can be carried around as a general camera on a daily basis, and can be cooled and photographed temporarily as needed, and its usefulness is extremely large.

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention.
FIG. 3 is a cross-sectional view illustrating a configuration of a main part of the electronic camera according to the embodiment. The same parts as those in FIG.
Detailed description is omitted.

The present embodiment differs from the above-described first embodiment in that the rear surface of the image sensor 22 is not directly cooled via the circuit board 23 but is directly cooled on the rear surface of the image sensor 22. That's what I did. That is, the image sensor 22
An opening is provided in the circuit board 23 on which the image sensor 22 is mounted, and the back surface of the image sensor 22 is exposed from the opening. The back surface of the imaging element 22 exposed at the opening is in direct contact with one surface of the wall constituting the pocket 12.

With such a configuration, the imaging device 22 can be cooled as required, and the same effects as those of the first embodiment can be obtained. The image sensor 22 can be efficiently cooled.

(Third Embodiment) FIG. 3 shows a third embodiment of the present invention.
1A is a view for explaining a basic configuration of an electronic camera according to the embodiment, FIG. 1A is a horizontal sectional view seen from above, and FIG.
Is a rear view, and (c) is a structural sectional view of a coolant unit. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

The present embodiment differs from the first embodiment described above in that a mounting pocket 16 to which a coolant unit 30 can be mounted is provided instead of the dry ice charging pocket 12. The pocket 16 is formed by providing a concave portion on the rear side 11 of the camera housing 10, and the coolant unit 30 is detachable.

The coolant unit 30 comprises a structure 31 having an internal cavity and a cool agent 32 filled and sealed in the cavity, and the outer shape of the unit 30 is determined so as to fit into the pocket 16. And in the mounted state,
As shown in FIG. 3A, the rear surface (exposed surface) of the unit 30 continuously forms the exterior surface of the camera housing 10.

The cooling agent 32 of the cooling unit 30 utilizes the heat storage effect of the latent heat of the substance and can be cooled very easily for a relatively long time by previously cooling it in, for example, a freezing room of a home refrigerator. It is assumed that. In addition, such a refrigerant itself has been put into practical use as a general-purpose refrigerant pack (in which a refrigerant is sealed in a soft plastic pack) used for homes such as "ice bags that do not require ice," and various kinds of compositions are used. Things exist. Coolant 32 in the context of the present invention
Can be used, but for example, a mixture of water, a gelling agent and ethylene glycol may be used.

With such a configuration, the coolant unit 30 can be used as a normal electronic camera with the coolant unit 30 mounted without any particular cooling. Alternatively, if the unit 30 is removed from the pocket 16 and used, the weight can be further reduced. On the other hand, by sufficiently cooling beforehand in the pocket 16 and then fitting the coolant unit 30, the image sensor 22 can be efficiently cooled, and an extremely low-luminance subject can be photographed like an astronomical photograph. It becomes possible. Therefore, the same effect as in the first embodiment can be obtained.

Also in this embodiment, similarly to the second embodiment, an opening is formed in the circuit board 23 and the image pickup device 22 is opened.
May be directly cooled.

Here, when the first and third embodiments are generally compared, they have the following features.

First Embodiment: It is not necessary to pre-cool the unit as in the third embodiment, so that it is excellent in immediacy.

Third Embodiment: There is no need to prepare a coolant, and in particular, since the unit can always be carried integrally with the camera, it can be used anywhere as long as there is a refrigerator, and cooling costs are virtually unnecessary. is there.

The present invention is not limited to the above embodiments. In the first embodiment, dry ice is used as the coolant to be charged into the coolant charging pocket. However, an ultra-small general-purpose refrigerant pack described above may be made and charged. Alternatively, a dedicated cooling agent unit corresponding to the shape of the pocket may be prepared and inserted. In this case, it can be said that in the third embodiment, a lid is provided in the pocket. Further, if the pocket is configured to have a waterproof structure, it is possible to use ice, and there is an effect that availability of a usable coolant is significantly increased.

The lid shown in the figure has an outwardly open structure with a hinge. However, if it is configured as a slide type (sliding laterally open), it can be used even with the lid open, so that the lid can be used. In such a case, there is an effect that the heat radiation effect at all times when the coolant is not inserted is improved.

In the third embodiment, a cooling unit filled with a cooling agent inside (referred to as a cooling agent type) is used as the cooling unit. However, the present invention is not limited to this. May be provided with a pocket having a lid portion, into which can be put. In this case, the coolant unit (referred to as a pocket type) having such a configuration and the above-described coolant type unit can be formed in a common mounting shape, and can be configured to be exchangeable for one camera. Such a configuration has an extremely large effect having all the features of versatility and low cost by using a pocket type unit as needed, and by using a cold storage type unit as needed.

The opening position of the pocket of the camera is not limited to the rear side of the camera body. If you want to place the monitor LCD in the center position on the back of the camera, or if you have a body that is long in the direction of the lens optical axis, such as a video movie,
It can be provided on any surface as needed, such as by providing a pocket opening on the top side of the camera body (and thus on the rear side of the image sensor). In addition, various modifications can be made without departing from the scope of the present invention.

[0035]

As described in detail above, according to the present invention, a pocket for introducing a coolant or a pocket for attaching a coolant unit is provided near the image sensor, so that the image sensor can be simplified as required. Can be cooled. In this case, the imaging device can be cooled without increasing the size of the device or increasing the cost, and long-time exposure such as in astrophotography can be performed.

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view and a rear view for explaining a basic configuration of an electronic camera according to a first embodiment.

FIG. 2 is an exemplary cross-sectional view illustrating a main configuration of an electronic camera according to a second embodiment;

FIG. 3 is a horizontal sectional view and a rear view for explaining a basic configuration of an electronic camera according to a third embodiment, and a structural sectional view of a cooling unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Camera housing 11 ... Back side (back of camera) 12 ... Coolant charging pocket 13 ... Lid 14 ... Lock mechanism 16 ... Coolant unit mounting pocket 21 ... Lens 22 ... Image sensor 23 ... Circuit board 24 ... Cover Glass 25: Lead wire 30: Coolant unit

Claims (6)

[Claims] 1. An imaging device for forming an image of a subject obtained through a lens on a light receiving surface of an image sensor, and capturing an image of the subject with the image sensor. An imaging device having a pocket. 2. The device according to claim 1, wherein the pocket is located on the back side of the image sensor and has a room-like structure having a lid. The lid continuously connects an exterior surface of an apparatus housing containing the image sensor and the lens. 2. The method according to claim 1, wherein
An imaging device according to any one of the preceding claims. 3. An imaging device for forming an image of a subject obtained through a lens on a light receiving surface of an image sensor, and capturing an image of the subject with the image sensor, wherein a coolant unit is mounted near the image sensor. An imaging device having a possible mounting pocket. 4. The imaging device according to claim 1, wherein the back surface of the imaging device is in contact with a wall surface of the room-like structure constituting the pocket directly or via a good heat conductor. Imaging device. 5. A coolant unit for cooling an image pickup device of an image pickup device provided with an image pickup device for photographing a subject image, the coolant unit being detachable from a pocket provided near the image pickup device of the image pickup device. A coolant unit, which is mounted on a coolant unit. 6. An imaging device according to claim 6, wherein said exposure surface in a state of being attached to a pocket provided near said imaging device is continuous with an exterior surface of a device housing containing said imaging device and a lens of said imaging device. 6. The coolant unit according to claim 5, wherein: