JP2005321490A - Camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera restrained from getting larger and realizing the higher power of a fuel cell. <P>SOLUTION: The camera is equipped with the fuel cell having a power generation cell (22) and a fuel tank (25) in which fuel supplied to the power generation cell is stored, and has a 1st main body part for holding an imaging device and a 2nd main body part (21) functioning as a grip part. The power generation cell is arranged in the 2nd main body part, and the fuel tank is arranged in the 1st and the 2nd main body parts respectively. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a camera using a fuel cell as a power source.

  Conventionally, a primary battery such as a manganese battery or a lithium battery, or a secondary battery such as a nickel-cadmium battery or a lithium ion battery is generally used as a power source for a portable device such as a camera. On the other hand, a fuel cell has higher energy per unit volume and unit weight than a conventional lithium battery, so if a fuel cell is used as a power source for a small electronic device, the small electronic device can be driven for a long time or downsized. Weight reduction can be achieved. In particular, it is possible to cope with an increase in power consumption in a digital camera that is becoming increasingly multifunctional.

  In addition, since the fuel cell can be used by replenishing the fuel, there is no need for frequent replacement and charging as in the case of a conventional primary battery, and the convenience when using the digital camera is improved.

  The fuel cell has a pair of electrodes (power generation cell portion) sandwiching an electrolyte and an external load circuit connecting the electrodes. Hydrogen ions (H +) and electrons (e−) are generated by supplying hydrogen or a fuel containing hydrogen to one electrode, and oxygen (air) is supplied to the other electrode (for example, Patent Documents). 1). Here, the electrode supplied with fuel is called a fuel electrode (anode), and the electrode supplied with oxygen is called an oxidant electrode (cathode).

A plurality of types of fuel cells have been proposed as the fuel cell having the above-described configuration. Here, a DHFC (Direct Hydrogen Fuel Cell) type fuel cell that supplies hydrogen directly to an electrode can obtain a high output as compared with a fuel cell that uses a fuel containing hydrogen such as methanol. Capacitance is possible. For this reason, the DHFC type fuel cell is most suitable as a power source for supplying power to a small portable device with large power consumption.
JP 2000-268835 A (paragraph numbers 0018 to 0025, FIG. 2)

  In a camera using a fuel cell as a power supply battery, in order to make the camera easy to use for a user, each member constituting the fuel cell is used so that a large-capacity fuel cell can be used while suppressing an increase in the size of the camera. Need to be placed. However, no proposal has been made for an optimal arrangement of the fuel cell to make an easy-to-use camera.

  An object of this invention is to provide the camera which has arrange | positioned the fuel cell in the optimal position.

  The present invention is a camera including a fuel cell having a power generation cell and a fuel tank that stores fuel supplied to the power generation cell, a first main body portion that holds an image sensor, and a second body as a grip portion. A power generation cell is disposed in the second body portion, and a fuel tank is disposed in the first and second body portions.

  According to the present invention, by disposing the power generation cell in the second main body portion as the grip portion, it is possible to suppress the enlargement of the camera while suppressing the enlargement of the camera as compared with the case where the power generation cell is disposed in another portion. The arrangement space can be increased. Moreover, a large-capacity fuel tank can be used by disposing the fuel tank in the first and second main body portions.

  Examples of the present invention will be described below.

  FIG. 1 is a cross-sectional view of a camera system that is Embodiment 1 of the present invention, and shows a state when the camera system is in a non-shooting state (subject observation state). The camera system of the present embodiment includes a camera body 1 and an interchangeable lens 9 that is attached to the camera body 1.

  In FIG. 1, an interchangeable lens 9 is attached to the camera body 1, and a subject light beam transmitted through a photographing optical system 9 a provided in the interchangeable lens 9 reaches a main mirror 8 disposed in the camera body 1. To do. Here, in the non-photographing state shown in FIG. 1, the main mirror 8 is disposed in the photographing optical path, and the subject luminous flux from the photographing optical system 9 a reaches the main mirror 8. Also, the alternate long and short dash line in FIG. 1 indicates the optical path of the subject luminous flux (part) in the non-shooting state.

  The main mirror 8 is composed of a half mirror, and reflects a part of the subject light beam emitted from the photographing optical system 9a and transmits the remaining light beam. The light beam reflected by the main mirror 8 is guided to a finder optical system having a focusing screen 12, a pentaprism 11, and a finder lens 13. Thereby, the photographer can observe the subject image via the finder optical system.

  On the other hand, the light beam transmitted through the main mirror 8 is reflected by the sub mirror 7 provided on the back surface (image surface side) of the main mirror 8 and guided to the focus detection unit 10 provided below the camera body 1. The focus detection unit 10 detects the focus state of the photographing optical system 9a by receiving the subject light flux from the sub mirror 7.

  The main mirror 8 and the sub mirror 7 are rotatably attached to a mirror box (see FIG. 3) described later, and operate by receiving a driving force from a driving source (not shown).

  A shutter unit that adjusts the amount of light incident on the image plane is disposed on the image plane side with respect to the main mirror 8 and the sub mirror 7. The shutter unit has an aperture mask 4, a shutter front curtain 5 and a shutter rear curtain 6. In the non-photographing state shown in FIG. 1, the shutter front curtain 5 is in a closed state (deployed state), and the opening of the aperture mask 4 is closed.

  On the image plane side with respect to the shutter unit, an optical filter 3 in which an optical low-pass filter and an infrared cut filter are integrated, a CCD that photoelectrically converts an object image (optical image) formed by the photographing optical system 9a into an electric signal, An image sensor 2 such as a CMOS sensor is disposed.

  When the camera system is switched from the non-photographing state to the photographing state, the main mirror 8 and the sub mirror 7 move above the camera body 1 so as to be retracted from the photographing optical path. As a result, the subject luminous flux from the photographing optical system 9a passes through the opening of the aperture mask 4 and the optical filter 3 as the shutter front curtain 5 switches from the closed state to the open state (superimposed state). Thereafter, the image sensor 2 is reached.

  After a predetermined time has elapsed since the shutter front curtain 5 switches to the open state, the shutter rear curtain 6 in the open state (the state shown in FIG. 1) switches to the closed state. Thereby, the exposure operation to the image sensor 2 is completed.

  The photographing operation described above is started when the photographer operates a release button (not shown) provided on the camera body 1.

  Further, in the above-described photographing operation, the image sensor 2 converts the subject image (optical image) into an electrical signal by photoelectric conversion, and reads the accumulated charge (image signal). Here, a charge reading circuit (not shown) scans and reads the converted charge for each horizontal line of the image sensor.

  The image signal read from the image sensor 2 is subjected to predetermined image processing, and then displayed as a captured image on a display unit (not shown) such as a TFT provided on the back surface of the camera body 1 or recorded. Or recorded on a medium (not shown). The photographer can check the captured image by viewing the display on the display unit.

  The camera system of this embodiment uses a fuel cell as a power source. Here, a general configuration of the fuel cell (DHFC type fuel cell) will be described with reference to FIGS. 6 and 7. Here, FIGS. 6 and 7 are a plan view and a front view of the fuel cell, respectively.

  A vent hole 53 is formed on the side surface of the housing 50 in order to take oxygen used for the reaction as an oxidant into the housing 50. Here, the vent hole 53 also has a role of releasing water (water vapor) and heat generated by power generation in the fuel cell to the outside of the housing 50.

  On the other hand, an electrode 52 for taking out electricity is provided on the upper surface of the housing 50 (the upper surface in FIGS. 6 and 7).

  Inside the housing 50, a cell 51, a fuel tank 56 that stores fuel (including hydrogen), a fuel supply path 55 that connects the fuel tank 56 and the cell 51 (a fuel electrode 502 described later), and a fuel tank 56 A pressure sensor 57 for measuring the internal pressure is arranged. Here, the cell 51 includes a fuel electrode 503, a polymer electrolyte membrane 502, an oxidant electrode 501, and a catalyst (not shown). 6 and 7 show a configuration in which two cells 51 are provided.

One cell 51 in the fuel cell configured as described above has an electromotive force of about 0.8 V and a current density of about 300 mA / cm ² . The size of the cell 51 is set to a size of about 1.2 cm × 2 cm. Here, if the eight cells 51 are connected in series, the output of the entire fuel cell becomes about 4.6 W at about 6.4 V and 720 mA.

  Although the fuel cell shown in FIGS. 6 and 7 has a configuration in which two cells 51 are stacked, a high voltage can be obtained by stacking a plurality of cells and connecting them in series.

  Next, the fuel tank 56 will be described. The fuel tank 56 is filled with a hydrogen storage alloy capable of storing hydrogen. Since the pressure resistance of the polymer electrolyte membrane 502 used in the fuel cell is 0.3 to 0.5 MPa, it is necessary to use a hydrogen storage alloy within the range where the differential pressure from the external pressure is within 0.1 MPa.

For example, LaNi ₅ is used as a hydrogen storage alloy having a hydrogen release pressure (dehydrogenation pressure) of 0.2 MPa at room temperature. If the volume of the fuel tank 56 is half the total volume of the fuel cell, the thickness of the fuel tank 56 is 1 mm, and the material of the fuel tank 56 is titanium, the weight of the fuel tank 56 is about 50 g and the volume is 5.2 cm ³ . Become. Since LaNi ₅ can absorb and desorb 1.1 wt% of hydrogen per unit weight, the amount of hydrogen stored in the fuel tank 56 is 0.4 g, and the energy that can be generated is about 11.3 [W · hr It becomes about 4 times compared with the energy of the conventional lithium ion battery.

  On the other hand, when using a hydrogen storage alloy whose hydrogen release pressure exceeds 0.2 MPa at room temperature, it is necessary to provide a pressure reducing valve between the fuel tank 56 and the fuel electrode 503.

  The hydrogen stored in the fuel tank 56 is supplied to the fuel electrode 503 through the fuel supply path 55. Further, outside air (including oxygen) is supplied to the oxidant electrode 501 through the vent hole 53. Electricity generated in the fuel cell is supplied from the electrode 52 to each circuit provided in the camera system.

  In addition, at the time of charging, at least a portion of each electrode (the fuel electrode 503 and the oxidizer electrode 501) in contact with water so that the electrode in the fuel cell does not conduct through the water for electrolysis. Is insulated. As the insulation treatment, there is a method in which a portion of the electrode that is not in contact with the polymer electrolyte membrane is covered with an insulator.

  FIG. 4 is a schematic diagram showing the configuration of the fuel cell provided in the camera body 1 of the present embodiment.

  The fuel tank 25 is filled with fuel (including hydrogen), and the fuel in the fuel tank 25 is supplied to the fuel electrode 201 in the power generation cell 22 through the fuel supply path 24. Here, the power generation cell 22 includes a fuel electrode 201, an oxidant electrode 203, and a polymer electrolyte membrane 204 disposed between the fuel electrode 201 and the oxidant electrode 203. A catalyst (not shown) for promoting a chemical reaction is provided between the fuel electrode 201 and the polymer electrolyte membrane 204 and between the oxidant electrode 203 and the polymer electrolyte membrane 204.

  When the fuel in the fuel tank 25 is supplied to the fuel electrode 201 through the fuel supply path 24, the fuel containing hydrogen or hydrogen ions is oxidized, so that electrons (e−) and hydrogen ions (H +) are generated. Generated. Then, hydrogen ions move from the fuel electrode 201 to the oxidant electrode 203 through the polymer electrolyte membrane 204 and react with the oxidant gas supplied to the oxidant electrode 203 to generate water. Here, oxygen present in the air outside the camera body is used as the oxidant gas.

  Oxygen in the air outside the camera system is supplied to the oxidant electrode 132 of the power generation cell 102 through the opening 202 formed in the camera body 1.

  Electrons (e−) generated by the oxidation of the fuel containing hydrogen supplied to the fuel electrode 201 from the negative electrode terminal provided at the end of the fuel electrode 201 to the positive electrode terminal provided at the end of the oxidant electrode 203. To generate a direct current, and electric power is supplied to an external load (electrical component disposed in the camera body 1) 205. Further, at the time of power generation, water is generated at the oxidizer electrode 203 by the combination of hydrogen ions and oxygen, and this water is discharged as water vapor from the opening 202 to the outside of the camera body 1.

  FIG. 2 is a top view of the camera system of the present embodiment, and shows the internal structure of the camera body with respect to the grip portion. FIG. 3 is a front view of the camera system of this embodiment, and also shows a part of the structure inside the camera.

  When the user uses the camera system, the grip part (second body part) 21 of the camera body 1 is held. Here, as shown in FIGS. 2 and 3, the grip portion 21 corresponds to a portion of the exterior of the camera body 1 that is within the range indicated by the region A. Moreover, the grip part 21 has the part which protrudes in the front surface of the camera main body 1, as shown in FIG.

  On the other hand, the interchangeable lens 9 can be attached to a portion (first main body portion) other than the grip portion 21 in the exterior of the camera body 1, that is, a portion within the range shown in the region B shown in FIGS. It is like that. Further, inside the camera body 1 other than the grip portion 21, the mirror box 23, the above-described imaging device 2, the focus detection unit 10, and the like are arranged.

  Inside the grip portion 21, a power generation cell 22 of a fuel cell is disposed (fixed). Here, by forming the power generation cell 22 in a shape that matches the shape of the grip portion 21, the space in the grip portion 21 can be used efficiently. Further, if the power generation cell 22 is configured by stacking a plurality of cells, a high output can be obtained, and a large current can be generated by increasing the surface area of each cell.

  In addition, the above-described opening 202 (see FIG. 4) is formed in the camera body 1. Here, if the opening 202 is formed on the upper surface of the grip portion 21, the opening 202 can be brought closer to the power generation cell 22 as compared with the case where the opening 202 is formed in another part of the camera body 1. Thereby, supply of air (oxygen) to the power generation cell 22 and discharge of water vapor generated in the power generation cell 22 can be performed efficiently.

  A fuel tank 25 is disposed below the camera body 1 with respect to the power generation cell 22, and the fuel tank 25 is arranged inside the grip portion 21 and inside the camera body 1 other than the grip portion 21 as shown in FIG. 3. Is arranged. The fuel tank 25 is connected to the power generation cell 22 through a fuel supply path 24 disposed (fixed) in the grip portion 21.

  Here, the fuel tank 25 is detachable from the fuel supply path 24 and is connected to the fuel supply unit 24 when the camera system is used. When the fuel in the fuel tank 25 becomes empty, the fuel tank 25 is removed from the fuel supply path 24 and a new fuel tank 25 filled with fuel is attached to the fuel supply path 24.

  In the present embodiment, the fuel tank 25 is detachable from the fuel supply path 24, but the fuel tank 25 may be fixed in the camera body 1. In this case, the fuel tank fixed in the camera body 1 is filled with fuel.

  However, if the fuel tank 25 is configured to be detachable from the fuel supply path 24, the camera system can continue to be used by replacing only the fuel tank. That is, when the fuel tank is fixed in the camera body, it is not necessary to perform the troublesome work of filling the fuel tank with fuel, and the usability of the camera system (camera body) is improved.

  A fuel cell lid 26 is provided on the lower surface of the camera body 1, and the fuel cell lid 26 opens and closes the storage port of the fuel tank 25. Here, the fuel cell lid 26 is located in the region A and the region B as shown in FIG. When the fuel tank 25 is replaced, the fuel cell lid 26 in the closed state is opened.

  A mirror box 23 that rotatably holds the main mirror 8 (including the sub mirror 7) described above is disposed behind the interchangeable lens 9 (on the image plane side). A focus detection unit 10 is disposed in the lower region. As shown in FIG. 3, the focus detection unit 10 has a shorter length in the lateral direction of the camera body 1 (lateral direction in FIG. 3) than the mirror box 23.

  Here, a part of the fuel tank 25 is in a region on the bottom surface side of the camera body 1 with respect to the mirror box 23 and is generated due to a difference in length between the focus detection unit 10 and the mirror box 23 as described above. Located in the area.

  In the camera system of the present embodiment, since the power generation cell 22 of the fuel cell is disposed in the grip portion 21 of the camera body 1, compared to the case where the power generation cell 22 is disposed in another region in the camera body 1, The arrangement space of the power generation cells 22 can be increased without increasing the size of the camera body 1. Thereby, since the electric power generation cell comprised by laminating | stacking a some cell can be used, high output can be obtained. In addition, since the surface area of each cell can be increased, a large current can be obtained by increasing the surface area of each cell.

  In addition, since the fuel tank 25 is disposed in the lower region of the camera body 1 with respect to the power generation cell 22 and the fuel cell lid 26 is provided on the bottom surface of the camera body 1, the fuel tank 25 can be replaced simply by opening the fuel cell lid 26. The frequent fuel tank 25 can be easily replaced. Since the camera system can be used continuously only by replacing the fuel tank 25, the usability of the camera system (camera body) is improved.

  Further, since the fuel tank 25 extends to a region below the mirror box 23 and is generated by a difference in lateral width between the focus detection unit 10 and the mirror box 23, the fuel tank 25 is only in the grip portion 21. Compared to the arrangement, the capacity of the fuel tank can be increased. Thus, by increasing the capacity of the fuel tank, the power capacity of the fuel cell can be increased.

  In addition, since the fuel tank 25 is arranged using the space (dead space) generated by the difference in size between the focus detection unit 10 and the mirror box 23, the space in the camera body 1 can be used efficiently. The camera body 1 is not unnecessarily enlarged.

  In the present embodiment, the configuration in which the power generation cell 22 and the fuel supply path 24 are fixed in the grip portion 21 has been described. However, the configuration in which at least one of the power generation cell 22 and the fuel supply path 24 can be detached from the grip portion 21. It is good.

  A power generation cell of a fuel cell may have a decrease in power generation efficiency due to exhaustion of a catalyst inside the power generation cell and deterioration of a polymer electrolyte membrane due to long-term use. Also, the fuel supply path may be deteriorated by long-term use. Furthermore, there is a possibility that the power generation cell and the fuel supply path may be damaged by an external impact or the like.

  For this reason, it is possible to easily replace the deteriorated power generation cell and the fuel supply path by configuring the power generation cell and the fuel supply path to be removable from the grip portion as described above. In this case, for example, the power generation cell and the fuel supply path can be exchanged by opening the fuel cell lid 26 and removing the fuel supply path and the power generation cell together with the fuel tank 25.

  On the other hand, in this embodiment, as described above, a part of the fuel tank 25 is located in the lower region of the mirror box 23, but may not be located in the lower region of the mirror box 23. Good. In other words, in addition to the space in the grip part 21, the fuel tank 25 may be arranged using the space in the camera body 1 other than the grip part 21. With this configuration, the capacity of the fuel tank can be increased as compared with the case where the fuel tank 25 is disposed only in the grip portion 21.

  A plurality of fuel tanks may be arranged in the camera body 1. Specifically, one fuel tank is arranged in the grip part 21 and other fuel tanks are arranged in an area in the camera body 1 other than the grip part 21, and these fuel tanks are connected via a fuel supply path. You may make it supply a fuel to the power generation cell in the grip part 21. FIG. Here, the plurality of fuel tanks may be detachable from the camera body, or may be fixed in the camera body.

  In this embodiment, a camera system having a camera body and an interchangeable lens has been described. However, the present invention can also be applied to a lens-integrated camera. That is, in the lens-integrated camera having the external shape as shown in FIGS. 2 and 3, the power generation cell and the fuel supply path are arranged in the grip portion, and the fuel tank is placed in the grip portion and in a region other than the grip portion. Can be arranged. Here, the fuel tank can be disposed in a region formed on the bottom surface side of the camera with respect to the image sensor.

  FIG. 5 is a schematic diagram illustrating a configuration viewed from the front of a camera system that is Embodiment 2 of the present invention. Note that the present embodiment can also be applied to a lens-integrated camera.

  In this embodiment, the interchangeable lens 109 can be attached to and detached from the camera body 101. The grip unit (second main body) 131 held by the photographer is detachable from the camera main body 101 (first main body) having an image sensor and the like. In the grip unit 131, a power generation cell 122, a fuel supply unit 124, and a fuel tank 125 constituting a fuel cell are arranged. The fuel tank 125 is detachable from the fuel supply path 124.

  When the grip unit 131 is attached to the camera body 101, electric power generated by the fuel cell (power generation cell 122) is supplied to each electronic component in the camera body 101 via the fuel cell contact 141 provided in the grip unit 131. It has become so.

  On the other hand, a fuel cell lid 132 is provided on the lower surface of the grip unit 131 and opens and closes the storage port of the fuel tank 125. By opening the fuel cell lid 132, the fuel tank 125 can be removed from the fuel supply path 124. As a result, the fuel tank 125 in which the fuel has been consumed can be replaced with a new fuel tank that has been filled with fuel.

  In the camera system of the present embodiment, the grip unit 131 provided with the fuel cell can be detached from the camera body 101. Therefore, the fuel tank 125 can be replaced with the grip unit 131 removed from the camera body 101. .

  In this embodiment, the power generation cell 122 and the fuel supply path 124 are fixed to the grip unit 131, but at least one of the power generation cell 122 and the fuel supply path 124 may be detachable from the grip unit 131. If comprised in this way, even if the power generation cell 122 and the fuel supply path 124 deteriorate, it can be exchanged for a new power generation cell or fuel supply path.

  In this case, since the power generation cell and the fuel supply path can be replaced with the grip unit 131 removed from the camera body 101, the power generation cell and the like are replaced with the grip unit fixed to the camera body. Compared to the above, it is possible to easily replace the power generation cell and the like.

  On the other hand, the fuel tank 125 may be fixed to the grip unit 131. In this case, the fuel tank 125 can be easily replenished with fuel with the grip unit 131 removed from the camera body 101. That is, since the fuel can be replenished by holding only the grip unit 131, the fuel can be replenished more easily than when the grip unit 131 is fixed to the camera body 101 and the fuel is replenished. Can do.

FIG. 3 is a central cross-sectional view of the camera system that is Embodiment 1 in a non-photographing state. 1 is a top view of a camera system that is Embodiment 1. FIG. 1 is a front view of a camera system that is Embodiment 1. FIG. Schematic which shows the structure of a fuel cell. FIG. 6 is a front view of a camera system that is Embodiment 2. The top view which shows the structure of a fuel cell. The front view which shows the structure of a fuel cell.

Explanation of symbols

21: Grip part 22: Power generation cell 23: Mirror box 24: Fuel supply path 25: Fuel tank 131: Grip unit 122: Power generation cell 124: Fuel supply path 125: Fuel tank

Claims (7)

A camera provided with a fuel cell having a power generation cell and a fuel tank for storing fuel supplied to the power generation cell,
A first main body that holds the image sensor and a second main body serving as a grip;
The camera, wherein the power generation cell is disposed in the second main body, and the fuel tank is disposed in the first and second main bodies.   2. The camera according to claim 1, wherein a part of the fuel tank is disposed in a region of the first main body that extends downward with respect to an optical path toward the image sensor. A mirror member that reflects subject light from the photographing optical system, and a mirror box that supports the mirror member;
The camera according to claim 2, wherein a part of the fuel tank is disposed in a region that extends downward with respect to the mirror box. A focus detection unit disposed below the mirror box and performing focus detection based on subject light guided from the mirror member;
The camera according to claim 3, wherein the fuel tank is disposed adjacent to the focus detection unit. The fuel tank is attachable to the power generation cell;
The camera according to any one of claims 1 to 4, further comprising a lid member that opens and closes a storage port of the fuel tank. A camera with a fuel cell,
A camera comprising: a first main body portion that holds an imaging element; and a second main body portion that houses the fuel cell and is attached to the first main body portion. The fuel cell includes a power generation cell and a fuel tank that contains fuel supplied to the power generation cell and is attached to the power generation cell.
The camera according to claim 6, wherein the second main body has a lid member that opens and closes a storage port of the fuel tank.

Images