Imaging device

Abstract

The objective is to provide an imaging device that is compact and can suppress the occurrence of condensation on the front window component. [Solution] The imaging device is characterized by comprising an image sensor, a cooling element arranged to cool the image sensor, a front window member positioned opposite the image sensor, a sealed housing that houses the image sensor and the cooling element and to which the front window member is attached, and a heat transfer path that transfers heat from the heat dissipation surface of the cooling element to the front window member.

Description

Technical Field

[0006] , , ,

[0001] The present invention relates to an imaging device, and particularly to a structure for preventing dew condensation.

Background Art

[0002] It is known that the dark current of an image pickup device of a general imaging device increases as the temperature rises, and the noise increases. The noise caused by the dark current may deteriorate the quality of the captured image, particularly in the case of night surveillance or photography in a dark place. In order to prevent the temperature rise of such an image pickup device, there is an imaging device that cools the image pickup device using a cooling means such as a Peltier element and then performs photography.

[0003] Further, when the image pickup device is cooled, the temperature of a front window member such as an optical glass arranged to face the image pickup device decreases, and it is also known that dew condensation occurs on the side of the front window member facing the image pickup device and on the side facing the subject. Since the occurrence of dew condensation on the front window member may impair the quality of the captured image, a technique for preventing the occurrence of dew condensation on the front window member has also been disclosed.

[0004] For example, in Patent Document 1, a technique is disclosed in which the image pickup device is housed in a sealed space to prevent the intrusion of moisture into the sealed space and prevent dew condensation on the side of the front window member facing the image pickup device. Also, by making the front window member have a double window structure, the heat insulation performance is enhanced, the temperature of the side of the front window member facing the subject is prevented from decreasing, and a technique for preventing dew condensation on the side facing the subject is also disclosed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the prior art disclosed in Patent Document 1 mentioned above, at least two front window members are required on the subject side of the image sensor, and a gap for a heat insulating layer is required between the two front window members. In other words, space for the front window members and gaps is required in front of the image sensor.

[0007] In addition to the above, condensation can be prevented by maintaining a sufficient distance between the image sensor and the front window component so that the temperature of the front window component does not drop to the dew point. However, even in this case, space is required between the image sensor and the front window component.

[0008] Thus, with conventional technology, preventing condensation on the subject side of the front window requires space in front of the image sensor, which in turn leads to the need for a larger imaging device.

[0009] Therefore, the object of the present invention is to provide an imaging device that is compact and can suppress the occurrence of condensation on the front window member. [Means for solving the problem]

[0010] An imaging device according to one embodiment of the present invention is characterized by comprising: an image sensor; a cooling element disposed to cool the image sensor; a front window member disposed opposite the image sensor; a sealed housing that houses the image sensor and the cooling element and to which the front window member is attached; and a heat transfer path that transfers heat from the heat dissipation surface of the cooling element to the front window member. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an imaging device that is compact and can suppress the occurrence of condensation on the front window member. [Brief explanation of the drawing]

[0012] [Figure 1] This is a perspective view showing the external appearance of an imaging device according to Embodiment 1 of the present invention. [Figure 2] This is an exploded perspective view of the imaging device 1. [Figure 3]It is a front view showing the appearance of the sensor Peltier unit 200. [Figure 4] It is a perspective view showing the appearance of the sensor Peltier unit 200. [Figure 5] It is a cross-sectional view of the sensor Peltier unit 200. [Figure 6] It is an exploded perspective view of the sensor Peltier unit 200. [Figure 7] It is a partial perspective view of the sensor Peltier unit 200. [Figure 8] It is a partially exploded perspective view of the sensor Peltier unit according to Embodiment 2 of the present invention. [Figure 9] It is a partially exploded perspective view of the sensor Peltier unit according to Embodiment 3 of the present invention. [Figure 10] It is a cross-sectional view of the sensor Peltier unit according to Embodiment 3 of the present invention. [Figure 11] It is a front view of the sensor substrate according to Embodiment 3 of the present invention. [Figure 12] It is a rear view of the sensor substrate according to Embodiment 3 of the present invention.

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments. Also, the following embodiments do not limit the present invention according to the claims, and not all combinations of the features described in the present embodiments are essential for the solution means of the present invention. In each figure, the same member or element is given the same reference number, and duplicate explanations are omitted or simplified.

[0014] <Embodiment 1> Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. First, referring to FIGS. 1 and 2, the schematic configuration of the imaging device main body according to Embodiment 1 of the present invention will be described. FIG. 1 is a perspective view showing the appearance of the imaging device according to Embodiment 1 of the present invention. FIG. 2 is an exploded perspective view of the imaging device 1 in FIG. 1.

[0015] The imaging device 1 includes a lens 102, a front unit 100, a sensor Peltier unit 200, a control board 300, and a rear unit 101. The lens 102 forms the optical system of the imaging device 1 and is an interchangeable lens that can be exchanged with respect to the front unit 100. The front unit 100 is composed of a mount structure capable of attaching a generally known interchangeable lens and a metal base member. The user can detach and exchange various interchangeable lenses according to the subject and the shooting environment. Note that since any known structure may be used for the mount structure for the interchangeable lens, its detailed description is omitted.

[0016] The sensor Peltier unit 200 includes an image sensor 230 (see FIG. 5) described later inside and is attached and fixed to the front unit 100. The light incident on the lens 102 is guided to the image sensor 230, converted into electronic data, and then image - processed by the control board 300. The internal configuration of the sensor Peltier unit 200 will be described later.

[0017] The rear unit 101 includes a metal base part, at least one or more control boards 300, a cable connector and a switch (not shown). The video engine on the control board 300 performs image processing on the electronic data acquired by the image sensor 230. By connecting the imaging device 1 to an external device via the cable connector provided in the rear unit 101, it becomes possible to view and save the data shot by the imaging device 1 on the external device side. Also, the imaging device 1 main body can be controlled by using an external device or a switch connected via the cable connector on the control board 300. Here, the base part of the rear unit 101 is made of a metal such as aluminum die - cast so as to have sufficient strength to support and fix the switch and the cable connector. By attaching and fixing the rear unit 101 to the front unit 100, the exposed parts such as the sensor Peltier unit 200 and the control board 300 inside the imaging device 1 are covered, and the imaging device 1 is completed.

[0018] Next, the configuration of the sensor Peltier unit 200 will be described with reference to Figures 3 to 7. Figure 3 is a front view showing the external appearance of the sensor Peltier unit 200. Figure 4 is a perspective view showing the external appearance of the sensor Peltier unit 200. Figure 5 is a cross-sectional view of the sensor Peltier unit 200. Figure 7 is a partial perspective view of the sensor Peltier unit 200. Figure 7 shows the sensor Peltier unit 200 with the top cover 210, front window member 211, and glass packing 212 removed to reveal the internal structure.

[0019] The top cover 210, which serves as the first sealing member, is a roughly rectangular component that is hollow and has openings on two opposing planes. It is made of a metal such as aluminum die-cast to conduct heat easily and not allow water vapor to pass through. A glass packing 212, which is a packing material made of butyl rubber or fluororubber and has a shape substantially the same as the opening, is placed in one of the openings of the top cover 210. Furthermore, a front window member 211, which is an optical glass with a shape substantially the same as the opening, is adhesively fixed to the top cover 210 from above the glass packing 212. As a result, the glass packing 212 is compressed and sandwiched between the top cover 210 and the front window member 211, sealing the opening. Here, the front window member 211 is attached to the top cover 210 by adhesive fixing, but it may also be attached and fixed by adding a metal part not shown. In that case, the metal parts (not shown) are attached and fixed to the top cover 210 with screws or the like, and the front window member 211 and the glass packing 212 are compressed and sandwiched between the metal parts (not shown) and the top cover 210.

[0020] The Peltier element 220, which is a cooling element, is flat and hollow with a hole approximately in the center. It is positioned so that the opening of the top cover 210 and the hollow portion of the Peltier element 220 are approximately concentric with respect to the inside of the top cover 210. The Peltier element 220 has a Peltier element cooling surface 220b that cools the surroundings, and a Peltier element heat dissipation surface 220a that dissipates heat to the surroundings. The Peltier element 220 is positioned so that the Peltier element heat dissipation surface 220a faces the top cover 210.

[0021] The sensor base insulation material 222 is a roughly rectangular member with a hole approximately in the center, and is placed inside the top cover 210. By attaching the sensor base 221 to the top cover 210 via the sensor base insulation material 222, the transfer of heat from the top cover 210 to the sensor base 221 can be suppressed. At this time, by positioning the Peltier element 220 in the hole of the sensor base insulation material 222, the outer side surface of the Peltier element 220 is covered, insulating the Peltier element 220 from the surrounding members, and enhancing the cooling effect of the Peltier element 220. The sensor base insulation material 222 is preferably made of a plastic material such as PC (polycarbonate) which has low thermal conductivity.

[0022] The sensor base 221, which is a retaining member, is a substantially rectangular, flat member and has a connector opening 221a for inserting the sensor connector 232 and the sensor FPC 233. FPC is an abbreviation for Flexible printed circuits. The sensor base 221 is attached and fixed to the inside of the top cover 210 by fastening members 223 such as screws, via the Peltier element 220 and the sensor base insulation material 222. In other words, the Peltier element 220 and the sensor base insulation material 222 are compressed and clamped by the sensor base 221 and the top cover 210. At this time, the Peltier element 220 is positioned so that the Peltier element cooling surface 220b faces the sensor base 221. The Peltier element 220 is positioned so as to be able to cool the image sensor 230. Here, it is preferable that the sensor base 221 be made of a metal such as aluminum so as to have sufficient strength to compress and clamp the Peltier element 220 and so as to be able to efficiently transfer the heat generated from the image sensor 230 to the Peltier element 220. More preferably, by making at least a portion of the material of the sensor base 221 copper or a heat pipe, the thermal conductivity from the image sensor 230 to the Peltier element 220 can be increased, thereby improving the cooling efficiency of the Peltier element 220.

[0023] Furthermore, in order to prevent heat from flowing from the top cover 210 to the sensor base 221 via the fastening member 223, it is preferable to incorporate an insulating washer 224 made of an insulating material such as resin into the fastening member 223.

[0024] The insulating cushion 225, which is an insulating means, is a sheet material with substantially the same shape as the sensor base 221. By attaching it to the sensor base 221, it prevents the sensor base 221 from absorbing heat from surrounding materials, thereby improving the cooling efficiency of the Peltier element 220. Here, it is preferable that the insulating cushion 225 be made of a material that does not conduct heat well, such as PP (polypropylene) foam.

[0025] The sensor substrate 231 is an electronic circuit board on which an image sensor 230 is mounted on one side, and a sensor connector 232, which is a connector for communication with an external circuit board, is mounted on the other side, which is the back side of the first side. The sensor substrate 231 has a substrate opening in the area approximately in the center of the back side of the image sensor 230, so that at least a part of the back side of the image sensor 230 is exposed to the outside. The sensor substrate 231 is attached and fixed to the sensor base 221 by screws (not shown) so that the image sensor 230 and the front window member 211 face each other. The front window member 211 is positioned opposite the image sensor 230. Here, by positioning at least a part of the sensor substrate 231 or the image sensor 230 in the hollow portion of the Peltier element 220, space can be used effectively, and thus the sensor Peltier unit 200 can be miniaturized.

[0026] By applying the thermal grease 226 to the substrate opening of the sensor substrate 231 so that the image sensor 230 and the sensor base 221 are thermally connected, heat generated from the image sensor 230 can be efficiently transferred to the sensor base 221.

[0027] The sensor cushion 234 is a sheet material with substantially the same shape as the sensor substrate 231 and has a sheet opening in the center that is substantially the same shape as the image sensor 230. The sensor cushion 234 is attached and fixed to the surface of the sensor substrate 231 on which the image sensor 230 is mounted, so that the image sensor 230 is exposed through the sheet opening. This allows the gap between the sensor substrate 231 and the top cover 210 to be filled with the sensor cushion 234 after assembly, preventing dust from entering the space between the image sensor 230 and the front window member 211. In addition, the sensor cushion 234 insulates the top cover 210 and the sensor substrate 231, thereby improving the cooling efficiency of the image sensor 230.

[0028] The bottom cover 250, which is the second sealing member, is a flat plate-shaped component and has substantially the same shape as the other opening of the top cover 210. It is attached and fixed to the top cover 210 via a bottom packing 251, which is a packing material that has substantially the same shape as the opening. The bottom cover 250 closes the opening of the top cover 210. In other words, the bottom packing 251 is compressed and sandwiched between the top cover 210 and the bottom cover 250. Here, it is preferable that the bottom cover 250 be made of a metal such as aluminum die-cast that does not allow water vapor to pass through and has sufficient strength to compress the bottom packing 251. It is also preferable that the bottom packing 251 be made of fluororubber or butyl rubber, which does not allow water vapor to pass through easily.

[0029] The flexible connector sensor FPC233 connects the sensor connector 232 on the sensor board 231 to the control board 300, enabling various forms of communication. The drive cable (not shown) for the Peltier element 220 is connected to the control board 300, enabling control of the Peltier element 220.

[0030] Here, the drive cables for the sensor FPC233 and the Peltier element 220 can be connected to the control board 300 by inserting them through an opening (not shown) provided in the top cover 210 or the bottom cover 250. The gap between the drive cables for the sensor FPC233 and the Peltier element 220 and the opening can be sealed with adhesive or the like, but since this sealing technique is well known, a detailed description is omitted.

[0031] As described above, a sealed housing is formed by combining the top cover 210 and the bottom cover 250, completing the sensor Peltier unit 200. The sealed housing formed by combining the top cover 210 and the bottom cover 250 houses the image sensor 230 and the Peltier element 220.

[0032] The following describes a method for cooling the image sensor 230 using the Peltier element 220 and suppressing condensation on the front window member 211 without increasing the size of the sensor Peltier unit 200.

[0033] When the Peltier element 220 is driven, heat is transferred from the Peltier element cooling surface 220b to the Peltier element heat dissipation surface 220a. The heat generated from the image sensor 230 is transferred to the heat dissipation grease 226, the sensor base 221, and the Peltier element cooling surface 220b, thus lowering the temperature of the image sensor 230. On the other hand, the heat generated from the Peltier element heat dissipation surface 220a is transferred to the front window member 211 via the top cover 210, raising the temperature of the front window member 211. The top cover 210 is an example of a heat transfer path from the Peltier element heat dissipation surface 220a to the front window member 211. As the temperature of the front window member 211 rises, the temperature of the water vapor on the subject side of the front window member 211 does not decrease, making condensation less likely to occur. In this case, there is no need to make the front window member 211 a double-window structure or to increase the distance between the front window member 211 and the image sensor 230, thus keeping the size of the imaging device 1 down.

[0034] <Embodiment 2> The following describes Embodiment 2 of the present invention. The general configuration of the imaging device 1 according to Embodiment 2, which consists of a front unit 100, a sensor Peltier unit 200, a rear unit 101, and a control board 300, is the same as that of Embodiment 1, so the explanation is omitted. The structure in which the sensor Peltier unit 200 according to Embodiment 2 is sealed by a top cover 210, a bottom cover 250, and a front window member 211 is the same as that of Embodiment 1, so the explanation is omitted. The configuration in which the front window member 211 is attached to the top cover 210 of the sensor Peltier unit 200 according to Embodiment 2 is the same as that of Embodiment 1, so the explanation is omitted.

[0035] The internal configuration of the sensor Peltier unit 200 according to Embodiment 2 will be explained with reference to Figure 8. Figure 8 is a partially exploded perspective view of the sensor Peltier unit according to Embodiment 2 of the present invention. Figure 8 shows the sensor Peltier unit 200 according to Embodiment 2 with the top cover 210, front window member 211, and glass packing 212 removed to reveal the internal structure.

[0036] As shown in Figure 8, the sensor Peltier unit 200 according to Embodiment 2 is configured to have two Peltier elements 220. In Embodiment 2, there are at least two Peltier elements. Each of the two Peltier elements 220 is a rectangular flat plate and is positioned inside the top cover 210 and near the outer circumference of the sensor substrate 231, and is mounted and fixed so as to be compressed and sandwiched between the top cover 210 and the sensor base 221. At this time, the heat dissipation surface 220a of each of the two Peltier elements 220 is positioned to face the top cover 210. Here, it is preferable that the two Peltier elements 220 are positioned symmetrically with respect to the image sensor 230. This allows the two Peltier elements 220 to absorb heat from the image sensor 230 evenly, thereby increasing the cooling efficiency.

[0037] Furthermore, when the outer shape of the image sensor 230 is considered to be approximately rectangular, it is more preferable to place the Peltier element 220 on the longer side. In Embodiment 2, the Peltier element 220 is placed on the longer side of the image sensor 230. This shortens the distance from the center of the image sensor 230, which is the heat source, to the Peltier element 220, thereby increasing the cooling efficiency of the Peltier element 220.

[0038] The sensor base insulation material 222 is a roughly rectangular component with a hole approximately in the center, and is placed inside the top cover 210. By attaching the sensor base 221 to the top cover 210 via the sensor base insulation material 222, heat transfer from the top cover 210 to the sensor base 221 can be suppressed. The Peltier element 220, the desiccant 227, and the sensor substrate 231 are placed in the hole in the sensor base insulation material 222.

[0039] The sensor base 221 is a roughly rectangular, flat member and has a connector opening 221a (see Figure 6) for inserting the sensor connector 232 and the sensor FPC 233. The sensor base 221 is attached and fixed to the top cover 210 by fastening members 223 such as screws via the Peltier element 220 and the sensor base insulation material 222. In other words, the Peltier element 220 and the sensor base insulation material 222 are compressed and sandwiched between the sensor base 221 and the top cover 210. At this time, the Peltier element cooling surface 220b is positioned on the sensor base 221 side.

[0040] The sensor board 231 is an electronic circuit board equipped with an image sensor 230 and a sensor connector 232 for communication with external devices, and has a board opening on the back side of the image sensor 230. The sensor board 231 is positioned so that the image sensor 230 and the front window member 211 face each other, and is attached and fixed to the sensor base 221 with screws or adhesive (not shown).

[0041] By applying the thermal grease 226 (see Figure 5) to the substrate opening of the sensor substrate 231 so as to be in contact with the image sensor 230 and the sensor base 221, heat generated from the image sensor 230 can be efficiently transferred to the sensor base 221.

[0042] The desiccant 227 is a rectangular, flat sheet material composed of a desiccant such as silica gel. The desiccant 227 is placed near the outer periphery of the sensor substrate 231 on the sensor base 221. After assembling the sensor Peltier unit 200, the desiccant 227 absorbs moisture from the air contained inside, thereby preventing condensation from forming inside the sealed space. The desiccant 227 is a desiccant for absorbing moisture inside the sealed housing formed by combining the top cover 210 and the bottom cover 250.

[0043] Here, a connector opening 221a is required where the sensor connector 232 of the sensor base 221 is located. If the connector opening 221a and the Peltier element 220 are located on the same side, the connector opening 221a will be located between the image sensor 230 and the Peltier element 220, which may lengthen the heat transfer path and reduce thermal efficiency. Therefore, it is preferable to place the sensor connector 232 on a different side from the Peltier element 220.

[0044] Furthermore, it is preferable that the desiccant 227 be placed near the outer edge of the sensor substrate 231 and on an edge where the Peltier element 220 is not located. By utilizing the empty space where the Peltier element 220 is not located, it is not necessary to provide a separate space for the desiccant 227, thus preventing the sensor Peltier unit 200 from becoming larger.

[0045] The following describes a method for cooling the image sensor 230 using the Peltier element 220 and suppressing condensation on the front window member 211 without increasing the size of the sensor Peltier unit 200.

[0046] When each Peltier element 220 is driven, heat is transferred from the Peltier element cooling surface 220b to the Peltier element heat dissipation surface 220a. At this time, the heat generated from the image sensor 230 is transferred to each Peltier element cooling surface 220b via the thermal grease 226 and the sensor base 221, thereby lowering the temperature of the image sensor 230. On the other hand, the heat generated from each Peltier element heat dissipation surface 220a is transferred to the front window member 211 via the top cover 210, and by heating the front window member 211, condensation can be suppressed. The top cover 210 is an example of a heat transfer path from the Peltier element heat dissipation surface 220a to the front window member 211.

[0047] Embodiment 2 offers superior mass-producibility compared to Embodiment 1 due to the simpler shape of the Peltier element 220. Furthermore, by simplifying the shape of the Peltier element 220, the desiccant 227 and sensor connector 232 can be placed in the remaining space, allowing for further miniaturization of the sensor Peltier unit 200.

[0048] <Embodiment 3> The following describes Embodiment 3 of the present invention. The general configuration of the imaging device 1 according to Embodiment 3, which consists of a front unit 100, a sensor Peltier unit 200, a rear unit 101, and a control board 300, is the same as that of Embodiment 2, so the explanation is omitted. Also, the configuration in which the sensor Peltier unit 200 according to Embodiment 3 is sealed by a top cover 210, a bottom cover 250, and a front window member 211 is the same as that of Embodiment 2, so the explanation is omitted.

[0049] The internal configuration of the sensor Peltier unit 200 according to Embodiment 3 will be explained with reference to Figures 9 to 12. Figure 9 is a partial perspective view of the sensor Peltier unit 200 according to Embodiment 3. Figure 9 shows the sensor Peltier unit 200 with the top cover 210, front window member 211, and glass packing 212 removed to reveal the internal structure. Figure 10 is a cross-sectional view of the sensor Peltier unit 200 according to Embodiment 3. Figure 10 is a cross-sectional view at position AA shown in Figure 3. Figure 11 is a front view of the sensor substrate 231 according to Embodiment 3. Figure 12 is a rear view of the sensor substrate 231 according to Embodiment 3.

[0050] The two Peltier elements 220 are each rectangular flat plates and are positioned inside the top cover 210 and near the outer periphery of the sensor substrate 231. They are mounted and fixed so as to be compressed and sandwiched between the top cover 210 and the sensor base 221. At this time, the heat dissipation surfaces 220a of each of the two Peltier elements 220 are positioned to face the top cover 210.

[0051] The sensor base insulation material 222 is a roughly rectangular component with a hole approximately in the center, and is placed inside the top cover 210. By attaching the sensor base 221 to the top cover 210 via the sensor base insulation material 222, heat transfer from the top cover 210 to the sensor base 221 can be suppressed. The Peltier element 220, the desiccant 227, and the sensor substrate 231 are placed in the hole in the sensor base insulation material 222.

[0052] The sensor base 221, which is a retaining member, is a roughly rectangular member and has a sensor base opening 221b, which is a retaining member opening slightly larger than the image sensor 230. The sensor base 221 is attached and fixed to the top cover 210 by fastening members 223 such as screws, via the Peltier element 220 and the sensor base insulation material 222. In other words, the Peltier element 220 and the sensor base insulation material 222 are compressed and sandwiched by the sensor base 221 and the top cover 210. At this time, the Peltier element cooling surfaces 220b of each of the two Peltier elements 220 are positioned on the sensor base 221 side.

[0053] The sensor substrate 231 is a substrate equipped with an image sensor 230 and a sensor connector 232. The substrate portion is positioned on the opposite side of the sensor base 221 from the Peltier element 220, and the image sensor 230 is positioned so that it is exposed from the sensor base opening 221b toward the front window member 211. After the sensor substrate 231 is positioned relative to the sensor base 221 in the direction of the optical axis and perpendicular to the optical axis, it is fixed by bonding the gap between the image sensor 230 and the sensor base opening 221b with sensor bond 235. Furthermore, the sensor substrate 231 has a heat dissipation pattern 236 on its surface and interior, which consists of gold-plated patterns and through-holes, as a heat transfer means. The heat dissipation pattern 236 extends from near the image sensor 230 to near where the Peltier element 220 is attached on the sensor base 221, and can transfer the heat generated by the image sensor 230 to the Peltier element cooling surface 220b.

[0054] Here, since many patterns (not shown) for transmitting communication signals are arranged near the sensor connector 232, the space available for placing the heat dissipation pattern 236 may be limited. For this reason, it is preferable to place the sensor connector 232 on a different side from the Peltier element 220, thereby allowing for the placement of more heat dissipation patterns 236 and improving the cooling efficiency of the image sensor 230.

[0055] The thermal grease 226 is filled between the sensor base 221 and the sensor substrate 231. This ensures that even after the sensor substrate 231 is positioned and bonded to the sensor base 221, the sensor substrate 231 and the sensor base 221 remain thermally connected by the thermal grease 226. The sensor substrate 231 is mounted to the sensor base 221, which acts as a retaining member, in a way that allows for heat transfer.

[0056] The two desiccant 227 are each rectangular flat plates and are composed of a desiccant such as silica gel. The desiccant 227 are placed near the outer edge of the sensor substrate 231 on the sensor base 221, on the side where the Peltier element 220 is not located, so as to be optically symmetric with respect to the image sensor 230. After the sensor Peltier unit 200 is assembled, the desiccant 227 absorb moisture from the air contained inside, thereby preventing condensation inside the sealed space.

[0057] The following describes a method for cooling the image sensor 230 using the Peltier element 220 and suppressing condensation on the front window member 211 without increasing the size of the sensor Peltier unit 200.

[0058] When the Peltier element 220 is driven, heat is transferred from the Peltier element cooling surface 220b to the Peltier element heat dissipation surface 220a. The heat generated from the image sensor 230 is transferred to the heat dissipation pattern 236, the heat dissipation grease 226, the sensor base 221, and the Peltier element cooling surface 220b, thereby lowering the temperature of the image sensor 230. On the other hand, the heat generated from the Peltier element heat dissipation surface 220a is transferred to the front window member 211 via the top cover 210, raising the temperature of the front window member 211. The top cover 210 is an example of a heat transfer path from the Peltier element heat dissipation surface 220a to the front window member 211. As the temperature of the front window member 211 rises, the temperature of the water vapor on the subject side of the front window member 211 does not decrease, making condensation less likely to occur.

[0059] In this case, since there is no need to make the front window member 211 a double-window structure or to increase the distance between the front window member 211 and the image sensor 230, the size of the imaging device 1 can be kept down.

[0060] In Embodiment 3, compared to Embodiments 1 and 2, the position of the image sensor 230 is adjusted relative to the sensor base 221 in the direction of the optical axis and in the direction perpendicular to the optical axis, and then bonded and fixed with the sensor bond 235. Therefore, according to Embodiment 3, optical adjustments such as the flange back distance can be easily performed.

[0061] In the embodiments described above, the front window member 211 was made of optical glass, but the front window member 211 may be made of a transparent resin part such as polycarbonate, as long as moisture does not permeate into the sealed space of the sensor Peltier unit 200. Also, if necessary, the front window member 211 may be made of a translucent material with optical properties such as a low-pass filter or a high-pass filter.

[0062] Furthermore, in each of the embodiments described above, the glass packing 212 and bottom packing 251 were made of butyl rubber or fluororubber. However, the glass packing 212 and bottom packing 251 may be made of other elastic materials such as silicone rubber, as long as the airtightness of the sensor Peltier unit 200 is maintained. Also, the various packings may be omitted as long as the airtightness of the sensor Peltier unit 200 is maintained.

[0063] Furthermore, sheets or grease to enhance thermal conductivity may be applied to the contact surfaces between heat-transferring components, such as between the Peltier element 220 and the top cover 210, between the Peltier element 220 and the sensor base 221, and between the top cover 210 and the front window member 211. Conversely, if sufficient heat is transferred between the components, the heat dissipation sheets or thermal grease may be omitted.

[0064] Furthermore, in each of the embodiments described above, the Peltier element heat dissipation surface 220a is mounted so as to be in contact with the top cover 210. However, if the heat from the Peltier element 220 is transferred to the front window member 211 and sufficient compressive force is maintained on the Peltier element 220 and the glass packing 212, the Peltier element heat dissipation surface 220a may be in direct contact with the front window member 211.

[0065] Furthermore, in each of the embodiments described above, the Peltier element 220 and the sensor base insulation material 222 are fixed to the sensor base 221. However, if the sensor substrate 231 has sufficient strength, the Peltier element 220 and the sensor base insulation material 222 may be fixed directly to the sensor substrate 231.

[0066] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist.

[0067] This embodiment includes the following configuration. (Composition 1) Image sensor and A cooling element is arranged to cool the aforementioned image sensor, A front window member positioned opposite the image sensor, A sealed housing comprising the image sensor and the cooling element, and to which the front window member is attached, A heat transfer path from the heat dissipation surface of the cooling element to the front window member, An imaging device characterized by having the following features. (Configuration 2) The sealed housing comprises a first sealed member to which the front window member is attached, and a second sealed member that closes the opening of the first sealed member. The heat transfer path is formed by attaching and fixing the heat dissipation surface to the first sealing member or the front window member. The imaging apparatus according to configuration 1, characterized by the features described above. (Composition 3) The sensor substrate includes the image sensor, and the restraining member holds the cooling element together with the first sealing member or the front window member. The sensor substrate is mounted to the retaining member in a manner that allows heat to be transferred. The imaging apparatus according to configuration 2, characterized in that... (Composition 4) The cooling element has a hollow shape, and at least a portion of the image sensor or the sensor substrate is arranged in the hollow portion. The imaging apparatus according to configuration 2 or configuration 3, characterized in that it is a device. (Composition 5) The material of the aforementioned retaining member shall be, at least in part, copper or heat pipe. The imaging apparatus according to configuration 3, characterized by the above. (Composition 6) The aforementioned retaining member is insulated by an insulating means at least in part. The imaging device according to configuration 3 or configuration 5, characterized by the above. (Composition 7) The cooling element consists of at least two or more elements. The cooling element is arranged symmetrically with respect to the image sensor. The imaging apparatus according to configuration 2 or configuration 3, characterized in that it is a device. (Composition 8) The cooling element is positioned on the longer side of the image sensor. The imaging device according to configuration 7, characterized by the features described above. (Composition 9) The aforementioned sensor board is equipped with a sensor connector for communication, The sensor connector is positioned on one of the sides of the image sensor that does not have the cooling element. The imaging device according to configuration 7, characterized by the features described above. (Composition 10) The sealed enclosure includes a desiccant for absorbing moisture inside the enclosure, The desiccant is placed on the side of the image sensor where the cooling element is not located. The imaging device according to configuration 7, characterized by the features described above. (Composition 11) The retaining member has a retaining member opening that is larger than the image sensor, at least a portion of the image sensor is positioned in the retaining member opening, and has a heat transfer means that transmits the heat of the image sensor to the cooling element. The imaging apparatus according to configuration 3, configuration 5, or configuration 6, characterized in that it is a feature of the imaging apparatus according to configuration 3, configuration 5, or configuration 6. [Explanation of symbols]

[0068] 1. Imaging device 100 Front Unit 101 Rear Unit 102 Lens 200 Sensor Peltier Unit 210 Top Cover 211 Front window component 212 Glass gasket 220 Peltier elements 220a Peltier element heat dissipation surface 220b Peltier element cooling surface 221 Sensor Base 221a Connector opening 221b Sensor base aperture 222 Sensor-based insulation 223 Fastening Members 224 Insulating Washer 225 Insulating Cushion 226 Thermal grease 227 Dehumidifier 230 image sensors 231 Sensor board 232 Sensor Connector 233 Sensor FPC 234 Sensor Cushion 235 Sensor Bond 236 Heat dissipation patterns 250 Bottom Cover 251 Bottom packing 300 Control board

Claims

1. Image sensor and A cooling element is arranged to cool the aforementioned image sensor, A front window member positioned opposite the image sensor, A sealed housing comprising the image sensor and the cooling element, and to which the front window member is attached, A heat transfer path from the heat dissipation surface of the cooling element to the front window member, An imaging device characterized by having the following features.

2. The sealed housing comprises a first sealed member to which the front window member is attached, and a second sealed member that closes the opening of the first sealed member. The heat transfer path is formed by attaching and fixing the heat dissipation surface to the first sealing member or the front window member. The imaging apparatus according to feature 1.

3. The sensor substrate includes the image sensor, and a retaining member that holds the cooling element together with the first sealing member or the front window member. The sensor substrate is mounted to the retaining member in a manner that allows heat to be transferred. The imaging device according to feature 2.

4. The cooling element has a hollow shape, and at least a portion of the image sensor or the sensor substrate is arranged in the hollow portion. The imaging device according to feature 2.

5. The material of the aforementioned retaining member shall be, at least in part, copper or heat pipe. The imaging device according to feature 3.

6. The aforementioned retaining member is insulated by an insulating means at least in part. The imaging device according to feature 3.

7. The cooling element consists of at least two or more elements. The cooling element is arranged symmetrically with respect to the image sensor. The imaging device according to feature 2.

8. The cooling element is positioned on the longer side of the image sensor. The imaging apparatus according to feature 7.

9. The aforementioned sensor board is equipped with a sensor connector for communication, The sensor connector is positioned on one of the sides of the image sensor that does not have the cooling element. The imaging apparatus according to feature 7.

10. The sealed enclosure includes a desiccant for absorbing moisture inside the enclosure, The desiccant is placed on the side of the image sensor where the cooling element is not located. The imaging apparatus according to feature 7.

11. The retaining member has a retaining member opening that is larger than the image sensor, at least a portion of the image sensor is positioned in the retaining member opening, and has a heat transfer means that transmits the heat of the image sensor to the cooling element. The imaging device according to feature 3.

Images