Imaging device

Abstract

To provide an imaging device that can reduce the deterioration of dehumidification performance. [Solution] The system comprises an image sensor 103a, a cooling means 107 for cooling the image sensor 103a, a case comprising a first case 101 and a second case 102 for housing the image sensor 103a and the cooling means 107, a dehumidifying means 109 attached to the first case 101 for dehumidifying the inside of the case, a heat dissipation section 108 provided in the second case 102 and thermally connected to the cooling means 107, and flow paths 12-14 installed adjacent to the case for generating intake and exhaust airflow by a blower, wherein the heat dissipation section 108 is located inside the flow paths 12-14, and the moisture-dissipating surface 109a of the dehumidifying means 109 is located on the intake side of the heat dissipation section 108 and exposed inside the flow paths 12-14.

Description

Technical Field

[0001] The present invention relates to an imaging device provided with a dehumidifying means.

Background Art

[0002] Conventionally, in order to suppress deterioration of image quality due to an increase in the temperature of an image pickup device, an imaging device provided with a cooling element for cooling the image pickup device has been provided. In this type of imaging device, due to the characteristic that the image pickup device can be cooled below the ambient temperature by the cooling element, there is a possibility of condensation occurring due to the cooling of the cooling element in the housing that houses the image pickup device. When condensation occurs in the housing that houses the image pickup device, problems such as short - circuiting of electrical components are considered to occur. As a countermeasure against this, a configuration including a dehumidifying means for dehumidifying the inside of the housing that houses the image pickup device has been proposed. For example, Patent Document 1 discloses a technique in which a dehumidifying means is embedded in a wall surface near a cooling means so that moisture can be efficiently released.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An electrolytic dehumidifying element used as a dehumidifying means deteriorates in dehumidifying performance and has a short lifespan as the temperature increases. In Patent Document 1, the dehumidifying element is embedded in a radiator, and thus the temperature of the dehumidifying element is high, so there is a risk that the dehumidifying performance will easily deteriorate and the lifespan will be shortened.

[0005] The present invention has been made in view of the above points, and an object thereof is to provide an imaging device capable of reducing deterioration of dehumidifying performance.

Means for Solving the Problems

[0006] The present invention provides an imaging apparatus comprising: an image sensor; a cooling means for cooling the image sensor; a first case and a second case, the case housing the image sensor and the cooling means; a dehumidifying means attached to the first case for dehumidifying the inside of the case; a heat dissipation section provided in the second case and thermally connected to the cooling means; and a flow path installed adjacent to the case, which generates an intake and exhaust airflow by a blower, wherein the heat dissipation section is located inside the flow path, and the moisture-dissipating surface of the dehumidifying means is located on the intake side of the heat dissipation section and exposed inside the flow path. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an imaging device that can reduce the deterioration of dehumidification performance. [Brief explanation of the drawing]

[0008] [Figure 1] This is an exploded perspective view of the imaging device according to the first embodiment. [Figure 2] This is a perspective view of the imaging unit and its surrounding structure of the imaging apparatus according to the first embodiment. [Figure 3] This is an exploded perspective view of the imaging unit of the imaging device according to the first embodiment. [Figure 4] This is a cross-sectional view of the imaging unit and its surrounding structure of an imaging device according to the first embodiment. [Figure 5] This is an exploded perspective view of the imaging unit of the imaging device according to the second embodiment. [Figure 6] This is a cross-sectional view of the imaging unit and its surrounding structure of an imaging device according to the second embodiment. [Figure 7] This is a perspective view of the imaging unit and its surrounding structure of the imaging apparatus according to the third embodiment. [Figure 8] This is an exploded perspective view of the imaging unit of the imaging device according to the third embodiment. [Figure 9]This is a cross-sectional view of the imaging unit and its surrounding structure of an imaging device according to the third embodiment. [Modes for carrying out the invention]

[0009] Preferred embodiments of the present invention will be described below with reference to the attached drawings. Note that descriptions of components, parts, mounting structures, etc., that are not directly related to the present invention may be omitted or not shown. Furthermore, for the sake of clarity, the shapes of components and parts may be described in a simplified manner.

[0010] <First Embodiment> Referring to Figure 1, the schematic configuration of the imaging device 1 according to the first embodiment will be described. Figure 1 is an exploded perspective view of the imaging device 1. In this application, the front and back directions are defined with the shooting direction, which is the direction in which the image sensor 103a of the imaging unit 100 faces, as the front. The imaging device 1 comprises a main housing 4, a front housing 5, a rear housing 6, a first side panel 7, and a second side panel 8. The front housing 5, rear housing 6, first side panel 7, and second side panel 8 are fixed to the main housing 4 by fastening members (not shown), forming the exterior of the imaging device 1. Inside the imaging device 1, as will be described later, an imaging unit 100, an intake duct 12, an exhaust duct 13, a fan unit 14, and a control board 15 are installed.

[0011] The front housing 5 is provided with a mount section 5a to which an interchangeable lens for photographing a subject is attached. The rear housing 6 has several through holes (not shown), from which connectors (not shown) for connecting the imaging device 1 to external equipment and buttons (not shown) for inputting instructions to the imaging device 1 protrude. The first side panel 7 has an air intake port 7a. The air intake port 7a communicates with an air intake duct 12 installed inside the imaging device 1 and draws air into the air intake duct 12. The second side panel 8 has an exhaust port 8a. The exhaust port 8a communicates with an exhaust duct 13 installed inside the imaging device 1 and exhausts from the exhaust duct 13.

[0012] Next, referring to FIGS. 2 to 4, the internal configuration of the imaging device 1 will be described. FIG. 2 is a perspective view of the imaging unit 100 and its peripheral structure. FIG. 3 is an exploded perspective view of the imaging unit 100. FIG. 4 is a cross-sectional view of the imaging unit 100 and its peripheral structure. The case (housing) of the imaging unit 100 includes a first case 101 disposed on the imaging direction side and a second case 102 disposed on the side opposite to the imaging direction, and a substantially sealed space is formed inside. The second case 102 has a substantially plate shape, and the first case 101 has a substantially thin box shape with an opening on the surface facing the second case 102. The imaging unit 100 is fixed to the front housing 5 by, for example, an attachment structure not shown.

[0013] As shown in FIGS. 3 and 4, inside the imaging unit 100, from the side of the first case 101, an imaging substrate 103 including an image sensor 103a, a cooling block 104 and a heat insulating member 105 covering the same, and a Peltier element 107 for cooling the image sensor 103a are arranged and accommodated. Further, an electrolytic dehumidifying element 109 is attached to the first case 101 as a dehumidifying means for dehumidifying the inside of the case.

[0014] The second case 102 has a through hole 102a. From the through hole 102a, an imaging substrate cable 103b, a Peltier element cable 107b, and a dehumidifying element cable 109b can be led out to the outside of the imaging unit 100. The imaging substrate cable 103b is a cable for transmitting signals from the imaging substrate 103. The Peltier element cable 107b is a cable for supplying power to the Peltier element 107. The dehumidifying element cable 109b is a cable for supplying power to the dehumidifying element 109. By sealing the gaps between the through hole 102a and the respective cables 103b, 107b, 109b with rubber or an adhesive, the inside of the imaging unit 100 can be kept airtight.

[0015] On the rear side of the imaging unit 100, an intake duct 12, an exhaust duct 13, and a fan unit 14 incorporating a fan 14a (see FIG. 4) as a blowing means are installed. The intake duct 12 is adjacent to and fixed to the rear surface of the second case 102. Also, the fan unit 14 and the exhaust duct 13 are arranged behind the intake duct 12, and the intake duct 12 and the exhaust duct 13 are connected via the fan unit 14. The intake duct 12, the exhaust duct 13, and the fan unit 14 constitute a flow path that intakes air from the intake port 7a of the first side panel 7 and exhausts air from the exhaust port 8a of the second side panel 8 as shown by the dotted arrow A in FIG. 2. Through this flow path, the heat and internal moisture of the imaging unit 100 can be discharged to the outside of the imaging device 1. Thus, a flow path is formed that is installed adjacent to the second case 102 of the imaging unit 100 and in which an air flow for intake and exhaust by the blowing means occurs.

[0016] Behind the imaging unit 100, more specifically, behind the fan unit 14 and the exhaust duct 13, a control board 15 is arranged. To the control board 15, an imaging board cable 103b connected to the imaging element 103a, a Peltier element cable 107b connected to the Peltier element 107, a dehumidifying element cable 109b connected to the dehumidifying element 109, and a fan cable 14b connected to the fan unit 14 are connected. The control board 15 performs processing of signals from the imaging element 103a, control of the operation of the Peltier element 107, control of the operation of the dehumidifying element 109, and control of the operation of the fan unit 14.

[0017] Next, the imaging unit 100 will be described in detail. The second case 102 is made of a material with higher thermal conductivity than the first case 101, which in this embodiment is metal, and has a Peltier element contact surface 102b that the heat dissipation surface of the Peltier element 107 contacts. A heat sink 108, which is a heat dissipation member, is attached to the back of the second case 102, aligned with the position of the Peltier element contact surface 102b. As shown in Figure 4, the heat dissipation section made up of the heat sink 108 is placed inside the intake duct 12 that constitutes the flow path. The heat transferred from the heat dissipation surface of the Peltier element 107 to the second case 102 and the heat sink 108 is discharged to the outside of the imaging device 1 by the airflow in the flow path.

[0018] The front surface of the second case 102 (the surface facing the first case 101) has a groove along its outer circumference, into which the first case packing 110 is fitted. The second case 102 also has an opening 102c that communicates with the intake duct 12. The front surface of the second case 102 has a groove around the opening 102c, into which the second case packing 111 is fitted. The opening 102c is an opening that exposes the moisture-releasing surface 109a of the dehumidifying element 109 attached to the first case 101 to the inside of the intake duct 12.

[0019] The Peltier element 107 is a semiconductor element that absorbs heat (cools) on one side and generates heat (dissipates heat) on the other side when an electric current is applied. The Peltier element 107 is positioned so that its cooling surface is in contact with the cooling block 104 and its heat dissipation surface is in contact with the Peltier element contact surface 102b of the second case 102.

[0020] The cooling block 104 is made of metal and has a protrusion 104a that the image sensor 103a contacts. The side opposite to the protrusion 104a is positioned to contact the cooling surface of the Peltier element 107 through the opening 105b of the heat insulating member 105. The cooling block 104 is fixed to the second case 102 together with the heat insulating member 105 by a plurality of fastening members 113 arranged around the protrusion 104a. As a result, the Peltier element 107 is sandwiched between the cooling block 104 and the second case 102.

[0021] Around the Peltier element 107, a resin-based heat insulating member 105 is sandwiched between the cooling block 104 and the second case 10 to reduce the heat transferred from the second case 102 to the cooling block 104. The heat insulating member 105 has a wall portion 105a configured to surround the cooling block 104, reducing the heat transferred from the air inside the imaging unit 100 to the cooling block 104. In addition, a resin-based heat insulating washer 114 is sandwiched between the cooling block 104 and the seating surface of the fastening member 113 to reduce the heat transferred from the second case 102 through the fastening member 113 to the cooling block 104.

[0022] The imaging substrate 103 is positioned such that the image sensor 103a is in contact with the protrusion 104a of the cooling block 104, and is fixed to the cooling block 104. With this configuration, by energizing the Peltier element 107, the heat from the image sensor 103a is absorbed by the Peltier element 107 via the cooling block 104, thereby lowering the temperature of the image sensor 103a. This suppresses the deterioration of image quality that occurs when the temperature of the image sensor 103a rises.

[0023] Furthermore, a heat dissipation sheet or thermal grease (not shown) may be interposed between the image sensor 103a and the protrusion 104a of the cooling block 104. Also, a heat dissipation sheet or thermal grease (not shown) may be interposed between the cooling block 104 and the cooling surface of the Peltier element 107. Furthermore, a heat dissipation sheet or thermal grease (not shown) may be interposed between the heat dissipation surface of the Peltier element 107 and the Peltier element contact surface 102b of the second case 102. Furthermore, a heat dissipation sheet or thermal grease (not shown) may be interposed between the second case 102 and the heat sink 108.

[0024] The first case 101 is made of a material with lower thermal conductivity compared to the second case 102, and in this embodiment, it is made of resin. The first case 101 is fixed to the second case 102 by a plurality of fastening members 115. As a result, the case packings 110 and 111 are sandwiched between the first case 101 and the second case 102, forming part of a sealed housing.

[0025] The first case 101 is provided with a first opening 101a and a second opening 101b. The first opening 101a is an opening for allowing light to enter the image sensor 103a. The first case 101 is also provided with a bulge 101c in the direction toward the second case 102, and the second opening 101b is formed inside the bulge 101c. A groove is provided on the front surface of the first case 101 around the first opening 101a, and a cover glass packing 120 is fitted into this groove. A groove is also provided on the front surface of the first case 101 around the second opening 101b, and a case lid packing 121 is fitted into this groove.

[0026] A cover glass retaining member 118 is attached to the front of the first case 101. The cover glass retaining member 118 is made of sheet metal and is fixed to the first case 101 so as to sandwich the cover glass 117 and the cover glass packing 120. As a result, the first opening 101a of the first case 101 is covered by the cover glass 117, and the inside of the imaging unit 100 is kept airtight by the cover glass packing 120. The cover glass 117 is made of a transparent material such as glass so that light incident from the front housing 5 reaches the image sensor 103a.

[0027] Furthermore, a case cover 119 is attached to the front of the first case 101. The case cover 119 is made of sheet metal and is fixed to the first case 101 so as to sandwich the case cover packing 121. As a result, the second opening 101b of the first case 101 is covered by the case cover 119, and the inside of the imaging unit 100 is kept sealed by the case cover packing 121.

[0028] The dehumidifying element 109 is a dehumidifier that removes water vapor from the air by electrolysis using a solid polymer electrolyte membrane. When a voltage is applied to the anode and cathode of the dehumidifying element 109, water molecules are decomposed into hydrogen ions and oxygen on the anode side, reducing humidity, and the decomposed hydrogen ions react with oxygen in the air on the cathode side to form water molecules which are then released. The dehumidifying element 109 is fixed to the second opening 101b of the bulge 101c of the first case 101, for example, by screwing it in. A dehumidifying element packing 112 is sandwiched between the dehumidifying element 109 and the first case 101. The dehumidifying element 109 dehumidifies the inside of the imaging unit 100 and prevents condensation from occurring due to the cooling of the Peltier element 107. The moisture-releasing surface 109a of the dehumidifying element 109 is exposed to the inside of the intake duct 12 through the opening 102c of the second case 102, and the water molecules released from the moisture-releasing surface 109a (moisture inside the imaging unit 100) by the airflow in the flow path are discharged to the outside of the imaging device 1.

[0029] Furthermore, each packing 110, 111, 112, 120, and 121 is preferably made of an elastic material such as butyl rubber or fluororubber that is impermeable to water vapor in order to improve the airtightness of the inside of the imaging unit 100.

[0030] Next, the wiring layout of the imaging unit 100 will be described with reference to Figures 2 and 3. As described above, the imaging substrate cable 103b, the Peltier element cable 107b, and the dehumidifying element cable 109b are led out of the imaging unit 100 through the through hole 102a of the second case 102. At this time, the gap between the through hole 102a and each cable 103b, 107b, and 109b is sealed with rubber or adhesive to keep the inside of the imaging unit 100 airtight. Here, the through-hole 102a is positioned on the same side as the dehumidifying element 109 relative to the image sensor 103a. That is, the through-hole 102a and the dehumidifying element 109 are positioned within a range of less than 180 degrees around the optical axis R (see Figure 3) of the light incident on the image sensor 103a. This allows the space required for positioning the dehumidifying element 109 to be utilized for the wiring layout, and facilitates sealing when the imaging substrate cable 103b, Peltier element cable 107b, and dehumidifying element cable 109b are brought out to the outside of the imaging unit 100.

[0031] In this embodiment, a terminal (not shown) for the dehumidifying element cable 109b of the dehumidifying element 109 is located inside the imaging unit 100, and the dehumidifying element cable 109b needs to be led out to the outside of the imaging unit 100, but this is not limited to this configuration. The terminal for the dehumidifying element cable 109b may be located outside the imaging unit 100. In this case, even if the dehumidifying performance of the dehumidifying element 109 deteriorates over time, the dehumidifying element 109 can be easily replaced with a new one.

[0032] Next, with reference to Figures 3 and 4, a configuration that reduces the degradation of the dehumidifying element 109 and extends its lifespan will be described. The dehumidifying performance of the electrolytic dehumidifying element 109 deteriorates and its lifespan shortens as the temperature increases. Therefore, in order to reduce the deterioration of the dehumidifying element 109 and extend its lifespan, it is desirable to reduce the temperature rise of the mounting part of the dehumidifying element 109 and the temperature rise of the atmosphere in which the dehumidifying element 109 is exposed.

[0033] First, we will describe a configuration that reduces the temperature rise at the mounting portion of the dehumidifying element 109. The second case 102 is made of a metal with high thermal conductivity in order to transfer heat from the heat dissipation surface of the Peltier element 107 to the heat sink 108. Therefore, the second case 102 is prone to temperature rise, and if a dehumidifying element 109 is attached to the second case 102, the dehumidifying element 109 will also be prone to temperature rise.

[0034] In this embodiment, the first case 101 and the second case 102 sandwich the first case packing 110 and the second case packing 111 to form a part of the sealed housing, and come into contact only at the fastening portion of the fastening member 115. The first case 101 is molded from a resin with low thermal conductivity and functions as an insulating material, so heat is not easily transferred from the second case 102 to the first case 101 at the fastening portion between the first case 101 and the second case 102. Also, the first case packing 110 and the second case packing 111 are made of rubber with low thermal conductivity and function as insulating materials, so heat is not easily transferred from the second case 102 to the first case 101 via the first case packing 110 and the second case packing 111. In this way, the first case 101 and the second case 102 are thermally isolated, and the temperature of the first case 101 does not easily rise. By providing a mounting portion for the dehumidifying element 109 (a bulging portion 101c having a second opening 101b) in this first case 101, the temperature rise of the dehumidifying element 109 can be reduced.

[0035] Generally, since resin is more permeable to water vapor than metal, if it is desirable to suppress the intrusion of water vapor into the imaging unit 100 over time as a measure against condensation, it is desirable to make the first case 101 out of metal, just like the second case 102. In this case, by sandwiching a resin insulating washer (not shown) between the fastening portion of the first case 101 and the second case 102, the heat transferred from the second case 102 to the first case 101 can be reduced. Also, by sandwiching a resin insulating washer (not shown) between the first case 101 and the seating surface of the fastening member 115, the heat transferred from the second case 102 through the fastening member 115 to the first case 101 can be reduced. In this way, by interposing an insulating material between the first case 101 and the second case 102, it is possible to reduce the temperature rise of the first case 101 even if the first case 101 is made of metal. By attaching the dehumidifying element 109 to this first case 101, the temperature rise of the dehumidifying element 109 can be reduced.

[0036] Secondly, a configuration for reducing the temperature rise of the atmosphere in which the dehumidifying element 109 is exposed will be described. Specifically, a configuration for reducing the temperature rise of the air in the environment in which the moisture-releasing surface 109a of the dehumidifying element 109 is exposed will be described. The moisture-releasing surface 109a of the dehumidifying element 109 attached to the first case 101 is exposed to the inside of the intake duct 12 through the opening 102c of the second case 102. This allows the air flowing in the direction of the dotted arrow A shown in Figure 4 to efficiently discharge moisture from inside the imaging unit 100 to the outside of the imaging device 1.

[0037] Here, the temperature of the air inside the intake duct 12 is approximately the same as the ambient air temperature on the intake side of the heat sink 108. In contrast, on the exhaust side of the heat sink 108, the temperature rises above the ambient air temperature due to the forced air cooling of the heat sink 108, which is thermally connected to the heat dissipation surface of the Peltier element 107. Therefore, if the moisture-releasing surface 109a exposed inside the intake duct 12 is positioned on the exhaust side of the heat sink 108, it will be exposed to hotter air. For this reason, it is desirable to position it on the intake side of the heat sink 108. By positioning the moisture-releasing surface 109a of the dehumidifying element 109 on the intake side of the heat sink 108, it will not be affected by the temperature rise of the air due to the forced air cooling of the heat sink 108 and will be exposed to air at approximately the same temperature as the ambient air, thereby reducing the temperature rise of the dehumidifying element 109.

[0038] With the configuration described above, it is possible to provide an imaging device 1 that can reduce the temperature rise of the dehumidifying element 109 and reduce the deterioration of dehumidification performance.

[0039] <Second Embodiment> Next, a second embodiment will be described with reference to Figures 5 and 6. In the imaging device according to the second embodiment, the same reference numerals are used for the same components as in the imaging device 1 according to the first embodiment, and their detailed descriptions are omitted. The imaging device according to this embodiment differs from the imaging device 1 according to the first embodiment in the holding structure of the dehumidifying element 109 in the imaging unit. Figure 5 is a perspective view of the imaging unit 200 and its surrounding structure. Figure 6 is an exploded perspective view of the imaging unit 200. The imaging device according to this embodiment includes a holding member 222 for holding the dehumidifying element 109, and the dehumidifying element 109 is attached to the first case 201 via the holding member 222. That is, the first case 201 does not have a bulge 101c having a second opening 101b like the first case 101 of the first embodiment, but has a flat surface to which the holding member 222 is fixed. This makes it possible to simplify the shape and structure of the case of the imaging unit 200.

[0040] The first case 201 is made of a material with lower thermal conductivity compared to the second case 102, and in this embodiment, it is made of resin. Similar to the first embodiment, the first case 201 is fixed to the second case 102 by a plurality of fastening members 115, and the first case packing 110 is sandwiched between the first case 201 and the second case 102. In addition, the second case packing 111 around the opening 102c is sandwiched between the first case 201 and the retaining member 222.

[0041] The first case 201 is provided with an opening 201a. The opening 201a is an opening for allowing light to enter the image sensor 103a. Similar to the first embodiment, a cover glass retaining member 118 is attached to the front of the first case 201. The cover glass retaining member 118 is made of sheet metal and is fixed to the first case 201 so as to sandwich the cover glass 117 and the cover glass packing 120.

[0042] The dehumidifying element 109 is fixed to the holding member 222, for example, by screwing it in. A dehumidifying element packing 112 is sandwiched between the dehumidifying element 109 and the holding member 222. The dehumidifying element 109 dehumidifies the inside of the imaging unit 100 and prevents condensation from occurring due to the cooling of the Peltier element 107. The moisture-releasing surface 109a of the dehumidifying element 109 is exposed to the inside of the intake duct 12 through the opening 102c of the second case 102, and the water molecules released from the moisture-releasing surface 109a (moisture inside the imaging unit 100) by the airflow in the flow path are discharged to the outside of the imaging device.

[0043] As described above, in this embodiment, the dehumidifying element 109 is fixed to the first case 201 via the holding member 222, so there is no need to provide a mounting portion (a bulge portion 101c having a second opening 101b) in the first case 201. Therefore, the first case 201 does not have an opening corresponding to the second opening 101b of the first case 101 in the first embodiment, which allows for simplification of the shape and structure of the imaging unit 200 case and simplification of the sealing structure.

[0044] Furthermore, in this embodiment, compared to the first embodiment, the contact thermal resistance between the first case 201 and the holding member 222 increases as the thermal resistance of the heat conduction path from the second case 102 to the mounting portion of the dehumidifying element 109. As a result, heat is less likely to be transferred from the second case 102 to the holding member 222. Therefore, the temperature rise of the holding member 222, which is the mounting portion of the dehumidifying element 109, can be further reduced, and the temperature rise of the dehumidifying element 109 can be further reduced. The configuration for reducing the temperature rise of the atmosphere in which the dehumidifying element 109 is exposed is the same as in the first embodiment, and therefore its explanation will be omitted.

[0045] With the configuration described above, it is possible to provide an imaging device that can reduce the temperature rise of the dehumidifying element 109 and reduce the deterioration of dehumidification performance.

[0046] <Third Embodiment> Next, a third embodiment will be described with reference to Figures 7 to 9. In the imaging apparatus according to the third embodiment, the same reference numerals are used for the same components as in the imaging apparatus 1 according to the first embodiment, and their detailed descriptions are omitted. The imaging device according to this embodiment differs from the imaging device 1 according to the first embodiment in the position of the dehumidifying element 109 in the imaging unit and the configuration of the flow path. Figure 7 is a perspective view of the imaging unit 300 and its surrounding structure, where (a) is a rear perspective view seen from the exhaust duct 32 side and (b) is a rear perspective view seen from the intake duct 32 side. Figure 8 is an exploded perspective view of the imaging unit 300. Figure 9 is a cross-sectional view of the imaging unit 300 and its surrounding structure.

[0047] The case (housing) of the imaging unit 300 comprises a first case 301 positioned on the side facing the imaging direction and a second case 302 positioned on the opposite side facing the imaging direction, forming a substantially sealed space inside. In the first embodiment, the cases (first case 101 and second case 102) are shaped like vertical boxes in order to provide an opening 102c for exposing the moisture-releasing surface 109a of the dehumidifying element 109. In contrast, in this embodiment, by changing the position of the dehumidifying element 109, the cases (first case 301 and second case 302) are shaped like boxes that are close to a square. This makes it possible to miniaturize the imaging unit 300 in a plane perpendicular to the optical axis R.

[0048] As shown in Figures 8 and 9, the imaging unit 300 houses, from the first case 301 side, an imaging substrate 103 equipped with an image sensor 103a, a cooling block 104 and a heat insulating member 105 covering it, and a Peltier element 107 for cooling the image sensor 103a. In addition, an electrolytic dehumidifying element 109 is attached to the first case 301 as a dehumidifying means for dehumidifying the inside of the case.

[0049] The second case 302 has a through hole 302a. The imaging substrate cable 103b, the Peltier element cable 107b, and the dehumidifying element cable 109b can be led out of the imaging unit 100 through the through hole 302a. By sealing the gap between the through hole 302a and each cable 103b, 107b, and 109b with rubber or adhesive, the inside of the imaging unit 100 can be kept airtight.

[0050] Behind the imaging unit 300, an intake duct 32, an exhaust duct 13, and a fan unit 14 containing a fan 14a (see Figure 9), which is a means of blowing air, are installed. The intake duct 32 consists of a first intake duct 32a, which is adjacent to and fixed to the side of the first case 301, and a second intake duct 32b, which is adjacent to and fixed to the rear of the second case 302. The intake duct 32, exhaust duct 13, and fan unit 14 form a flow path that draws in air from the intake port 7a of the first side panel 7 and exhausts it from the exhaust port 8a of the second side panel 8, as shown by the dotted arrow A in Figure 7. This flow path allows heat and internal moisture from the imaging unit 300 to be discharged to the outside of the imaging device. In this way, a flow path is formed that is installed adjacent to the first case 301 and the second case 302 of the imaging unit 300, and generates airflow for intake and exhaust by the blowing means.

[0051] Next, we will describe the imaging unit 300 in detail. The second case 302 is made of a material with higher thermal conductivity than the first case 301, which in this embodiment is metal, and has a Peltier element contact surface 302b that the heat dissipation surface of the Peltier element 107 contacts. A heat sink 108, which is a heat dissipation member, is attached to the back of the second case 302, aligned with the position of the Peltier element contact surface 302b. A heat dissipation sheet or thermal grease (not shown) may be interposed between the heat dissipation surface of the Peltier element 107 and the Peltier element contact surface 302b of the second case 302, or between the second case 302 and the heat sink 108. As shown in Figure 9, the heat dissipation section formed by the heat sink 108 is placed inside the intake duct 32 (second intake duct 32b) that constitutes the flow path. The heat transferred from the heat dissipation surface of the Peltier element 107 to the second case 302 and the heat sink 108 is discharged to the outside of the imaging device by the airflow in the flow path.

[0052] The front surface of the second case 302 (the surface facing the first case 301) has a groove along its outer circumference, into which the case packing 310 is fitted.

[0053] The first case 301 is made of a material with lower thermal conductivity than the second case 302, which in this embodiment is made of resin. The first case 301 is fixed to the second case 302 by a plurality of fastening members 115. As a result, the case packing 310 is sandwiched between the first case 301 and the second case 302, forming part of a sealed housing. It is preferable that the packing 310 be made of an elastic material such as butyl rubber or fluororubber that is impermeable to water vapor in order to improve the airtightness inside the imaging unit 100.

[0054] The first case 301 is provided with an opening 301a. The opening 301a is an opening for allowing light to enter the image sensor 103a. A groove is provided on the front surface of the first case 301 around the opening 301a, and the cover glass packing 120 is fitted into this groove. A cover glass retaining member 318 is attached to the front of the first case 301. The cover glass retaining member 318 is made of sheet metal and is fixed to the first case 301 so as to sandwich the cover glass 117 and the cover glass packing 120. As a result, the opening 301a of the first case 301 is covered by the cover glass 117, and the inside of the imaging unit 100 is kept airtight by the cover glass packing 120.

[0055] Furthermore, a mounting portion 301c having an opening 301b is provided on the side of the first case 301 (the side facing the first side panel 7 where the air intake port 7a is located). The dehumidifying element 109 is fixed to the opening 301b of the mounting portion 301c, for example, by screwing, so as to sandwich the dehumidifying element packing 112. At this time, the dehumidifying surface 109a of the dehumidifying element 109 is positioned to face outward. The dehumidifying element 109 dehumidifies the inside of the imaging unit 300 and prevents condensation from occurring due to the cooling of the Peltier element 107. The moisture-releasing surface 109a of the dehumidifying element 109 is exposed inside the air intake duct 32 (first air intake duct 32a), and water molecules (moisture inside the imaging unit 100) released from the moisture-releasing surface 109a by the airflow in the flow path are discharged to the outside of the imaging device.

[0056] Next, the wiring layout of the imaging unit 300 will be described with reference to Figures 7 and 8. As described above, the imaging substrate cable 103b, the Peltier element cable 107b, and the dehumidifying element cable 109b are led out of the imaging unit 100 through the through hole 302a of the second case 302. At this time, the gap between the through hole 302a and each cable 103b, 107b, and 109b is sealed with rubber or adhesive to keep the inside of the imaging unit 100 airtight. Here, similar to the through-hole 102a in the first embodiment, the through-hole 302a is positioned on the same side as the dehumidifying element 109 relative to the image sensor 103a. This allows the space required for the placement of the dehumidifying element 109 to be utilized for the wiring layout, and facilitates sealing when the image substrate cable 103b, Peltier element cable 107b, and dehumidifying element cable 109b are brought out to the outside of the imaging unit 100.

[0057] In this embodiment, as in the first embodiment, it is necessary to lead the dehumidifying element cable 109b to the outside of the imaging unit 300, but this is not limited to this. The terminal for the dehumidifying element cable 109b may be configured to be located outside the imaging unit 300. In this case, even if the dehumidifying performance of the dehumidifying element 109 deteriorates over time, the dehumidifying element 109 can be easily replaced with a new one.

[0058] Next, with reference to Figures 8 and 9, a configuration for reducing the degradation of the dehumidifying element 109 and extending its lifespan will be described. As mentioned in the first embodiment, in order to reduce the degradation of the dehumidifying element 109 and extend its lifespan, it is desirable to reduce the temperature rise of the mounting part of the dehumidifying element 109 and the temperature rise of the atmosphere in which the dehumidifying element 109 is exposed.

[0059] First, we will describe a configuration that reduces the temperature rise at the mounting portion of the dehumidifying element 109. In this embodiment, similar to the first embodiment, the first case 301 and the second case 302 sandwich the case packing 310 to form a part of the sealed housing and come into contact only at the fastening portion of the fastening member 115. The first case 301 is molded from a resin with low thermal conductivity and functions as an insulating material, so heat is not easily transferred from the second case 302 to the first case 301 at the fastening portion between the first case 301 and the second case 302. Also, the case packing 310 is made of rubber with low thermal conductivity and functions as an insulating material, so heat is not easily transferred from the second case 302 to the first case 301 via the case packing 310. In this way, the first case 301 and the second case 302 are thermally isolated, the temperature of the first case 301 does not rise easily, and by providing the mounting portion 301c for the dehumidifying element 109 on the first case 301, the temperature rise of the dehumidifying element 109 can be reduced.

[0060] Generally, since resin is more permeable to water vapor than metal, if it is desirable to suppress the intrusion of water vapor into the imaging unit 300 over time as a measure against condensation, it is desirable to make the first case 301 out of metal, just like the second case 302. In this case, by sandwiching a resin insulating washer (not shown) between the fastening portion of the first case 301 and the second case 302, the heat transferred from the second case 302 to the first case 301 can be reduced. Also, by sandwiching a resin insulating washer (not shown) between the first case 301 and the seating surface of the fastening member 115, the heat transferred from the second case 302 through the fastening member 115 to the first case 301 can be reduced. In this way, by interposing an insulating material between the first case 301 and the second case 302, it is possible to reduce the temperature rise of the first case 301 even if the first case 301 is made of metal. By attaching the dehumidifying element 109 to this first case 301, the temperature rise of the dehumidifying element 109 can be reduced.

[0061] Secondly, a configuration for reducing the temperature rise of the atmosphere in which the dehumidifying element 109 is exposed will be described. Specifically, a configuration for reducing the temperature rise of the air in the environment in which the moisture-releasing surface 109a of the dehumidifying element 109 is exposed will be described. The moisture-releasing surface 109a of the dehumidifying element 109 attached to the first case 301 is exposed to the inside of the intake duct 32 through the opening 301b of the first case 301. This allows the air flowing in the direction of the dotted arrow A shown in Figure 9 to efficiently discharge moisture from inside the imaging unit 300 to the outside of the imaging device.

[0062] Here, the temperature of the air inside the intake duct 32 is approximately the same as the ambient temperature on the intake side of the heat sink 108. In contrast, on the exhaust side of the heat sink 108, the temperature rises above the ambient temperature due to the forced air cooling of the heat sink 108, which is thermally connected to the heat dissipation surface of the Peltier element 107. Therefore, if the moisture-releasing surface 109a exposed inside the intake duct 32 is positioned on the exhaust side of the heat sink 108, it will be exposed to hotter air. For this reason, it is desirable to position it on the intake side of the heat sink 108. By positioning the moisture-releasing surface 109a of the dehumidifying element 109 on the intake side of the heat sink 108, it will not be affected by the temperature rise of the air due to the forced air cooling of the heat sink 108 and will be exposed to air at approximately the same temperature as the ambient air, thereby reducing the temperature rise of the dehumidifying element 109.

[0063] With the configuration described above, it is possible to provide an imaging device that can reduce the temperature rise of the dehumidifying element 109 and reduce the deterioration of dehumidification performance. Furthermore, by arranging the dehumidifying element 109 on the side of the case of the imaging unit 300, it becomes possible to miniaturize the imaging unit 300 in a plane perpendicular to the optical axis R.

[0064] Although the present invention has been described above along with its embodiments, these embodiments are merely examples of how the present invention can be implemented, and the technical scope of the present invention should not be interpreted as being limited by them. In other words, the present invention can be implemented in various forms without departing from its technical concept or its main features. The dimensions, materials, and relative positions of components described in the embodiments are arbitrary and can be changed depending on the configuration of the device to which the present invention is applied or various conditions.

[0065] This embodiment includes the following configuration. (Composition 1) Image sensor and A cooling means for cooling the image sensor, A case comprising a first case and a second case, which houses the image sensor and the cooling means, A dehumidifying means attached to the first case for dehumidifying the inside of the case, A heat dissipation section is provided in the second case and is thermally connected to the cooling means, The case is provided with a passage that is installed adjacent to the aforementioned case and generates an airflow for intake and exhaust by a blowing means, The heat dissipation section is arranged inside the flow path. An imaging device characterized in that the moisture-releasing surface of the dehumidifying means is arranged to be exposed inside the flow path on the intake side of the heat dissipation section. (Configuration 2) The imaging apparatus according to configuration 1, characterized in that the first case is arranged on the side facing the shooting direction, and the second case is arranged on the side opposite to the shooting direction. (Composition 3) The second case has through holes for leading out the cable connected to the image sensor and the cable connected to the cooling means to the outside. The imaging apparatus according to configuration 1 or 2, characterized in that the through hole is located on the same side as the dehumidifying means with respect to the image sensor. (Composition 4) The aforementioned flow path is installed adjacent to the second case, The imaging apparatus according to any one of configurations 1 to 3, characterized in that the moisture-releasing surface of the dehumidifying means is exposed to the inside of the flow path through an opening provided in the second case. (Composition 5) The aforementioned flow path is installed adjacent to the first case and the second case, The imaging apparatus according to any one of configurations 1 to 3, characterized in that the moisture-releasing surface of the dehumidifying means is exposed to the inside of the flow path through an opening provided in the first case. (Composition 6) The imaging apparatus according to any one of configurations 1 to 5, characterized in that the first case is made of a material with lower thermal conductivity compared to the second case. (Composition 7) The imaging apparatus according to any one of configurations 1 to 6, characterized in that the second case is made of metal. (Composition 8) The imaging apparatus according to any one of configurations 1 to 7, characterized in that the first case is made of resin. (Composition 9) An imaging apparatus according to any one of configurations 1 to 8, characterized in that an insulating material is interposed between the first case and the second case. (Composition 10) The dehumidifying means is provided with a holding member, The imaging apparatus according to any one of configurations 1 to 9, characterized in that the holding member is attached to the first case via the holding member. (Composition 11) The imaging apparatus according to configuration 10, characterized in that the holding member is made of resin. (Composition 12) The imaging apparatus according to any one of configurations 1 to 11, characterized in that the cooling means is a Peltier element. [Explanation of symbols]

[0066] 1: Imaging device, 12, 32: Intake duct, 13: Exhaust duct, 14: Fan unit, 14a: Fan, 100, 200, 300: Imaging unit, 101, 201, 301: First case, 101c: Bulging part, 102, 302: Second case, 102c: Opening, 103: Imaging substrate, 103a: Image sensor, 104: Cooling block, 105: Thermal insulation member, 107: Peltier element, 108: Heat sink, 109: Dehumidifying element, 109a: Moisture-releasing surface, 222: Holding member, 301b: Opening, 301c: Mounting part

Claims

1. Image sensor and A cooling means for cooling the image sensor, A case comprising a first case and a second case, which houses the image sensor and the cooling means, A dehumidifying means attached to the first case for dehumidifying the inside of the case, A heat dissipation section is provided in the second case and is thermally connected to the cooling means, The case is provided with a passage that is installed adjacent to the aforementioned case and generates an airflow for intake and exhaust by a blowing means, The heat dissipation section is arranged inside the flow path. An imaging device characterized in that the moisture-releasing surface of the dehumidifying means is arranged to be exposed inside the flow path on the intake side of the heat dissipation section.

2. The imaging apparatus according to claim 1, characterized in that the first case is arranged on the side facing the shooting direction, and the second case is arranged on the side opposite to the shooting direction.

3. The second case has through holes for leading out the cable connected to the image sensor and the cable connected to the cooling means to the outside. The imaging apparatus according to claim 1 or 2, characterized in that the through hole is located on the same side as the dehumidifying means with respect to the image sensor.

4. The aforementioned flow path is installed adjacent to the second case, The imaging apparatus according to claim 1 or 2, characterized in that the moisture-releasing surface of the dehumidifying means is exposed to the inside of the flow path through an opening provided in the second case.

5. The aforementioned flow path is installed adjacent to the first case and the second case, The imaging apparatus according to claim 1 or 2, characterized in that the moisture-releasing surface of the dehumidifying means is exposed to the inside of the flow path through an opening provided in the first case.

6. The imaging apparatus according to claim 1 or 2, characterized in that the first case is made of a material with lower thermal conductivity compared to the second case.

7. The imaging apparatus according to claim 1 or 2, characterized in that the second case is made of metal.

8. The imaging apparatus according to claim 1 or 2, characterized in that the first case is made of resin.

9. The imaging apparatus according to claim 1 or 2, characterized in that an insulating material is interposed between the first case and the second case.

10. The dehumidifying means is provided with a holding member, The imaging apparatus according to claim 1 or 2, characterized in that the retaining member is attached to the first case via the retaining member.

11. The imaging apparatus according to claim 10, characterized in that the holding member is made of resin.

12. The imaging apparatus according to claim 1 or 2, characterized in that the cooling means is a Peltier element.

Images