Abstract: A fuel cell system includes a fuel cell, an impedance measuring instrument, and a control device. The control device is connected to the impedance measuring instrument. The impedance measuring instrument measures the impedance of the fuel cell according to the AC impedance method. The control device stores in advance a reference value corresponding to a reference hydrogen concentration. The control device compares the real part Z? of impedance acquired via the impedance measuring instrument against the reference value. When Z? is equal to or greater than the reference value, the control device estimates the hydrogen concentration of the fuel cell to be equal to or less than the reference hydrogen concentration.

Abstract: A fuel cell system includes a fuel cell, an impedance measuring instrument, and a control device. The control device is connected to the impedance measuring instrument. The impedance measuring instrument measures the impedance of the fuel cell according to the AC impedance method. The control device stores in advance a reference value corresponding to a reference hydrogen concentration. The control device compares the real part Z? of impedance acquired via the impedance measuring instrument against the reference value. When Z? is equal to or greater than the reference value, the control device estimates the hydrogen concentration of the fuel cell to be equal to or less than the reference hydrogen concentration.

Abstract: The hydrogen concentration in an anode gas passage of a fuel cell is obtained. When the fuel cell system is started up, one of a first start-up control and a second start-up control is selected based on the obtained hydrogen concentration in the anode gas passage. In the first start-up control, the power generation of the fuel cell is started after purging the anode gas passage. In the second start-up control, the power generation of the fuel cell is started without purging the anode gas passage.

Abstract: A collector plate (14) is connected to an output terminal (16). The collector plate (14) is made such that heat capacity per unit area of a neighboring region (14A) thereof, which is near to a portion where the output terminal (16) is connected, is different to the heat capacity per unit area of other regions (14B, 14C). More specifically, the other regions (14B, 14C) are formed such that the heat capacity per unit area thereof is smaller than that of the neighboring region (14A).

Abstract: A fuel cell having a stack structure is provided. The fuel cell includes plural unit cells each of which includes an anode and a cathode which are provided on both sides of a predetermined electrolyte membrane, and a catalytic layer which is provided in at least one of the anode and the cathode, and which supports a catalyst for promoting an anode reaction or a cathode reaction, the plural unit cells being stacked to form a stack structure. In the fuel cell, the plural unit cells include a unit cell including a catalyst layer supporting a catalyst which is different from catalysts supported by catalyst layers of other unit cells in at least one of type, weight, and specific surface area.

Abstract: A fuel cell system includes a fuel cell (1) having a plurality of unit cells (1a) stacked on each other, first and second end plates (1b, 1c) between which the plurality of unit cells are interposed, and a gas supply passage (1d) and a gas discharge passage (1e), both extending in the stacking direction of the unit cells. An inlet (1f) of the gas supply passage (1d) and an outlet (1g) of the gas discharge passage (1e) are located on the first end plate side. A hydrogen concentration sensor (4) is disposed in the gas discharge passage and detects a hydrogen concentration in the gas discharged from the plurality of unit cells. An electricity generation process in the fuel cell is controlled based on the hydrogen concentration detected by a hydrogen concentration sensor (4).

Abstract: A fuel cell which does not discharge fuel gas supplied to an anode (22) thereof to the outside at least during normal power generation having a gas diffusion layer (15) of a conductive porous material stacked on the anode (22) and having fuel gas flow passages therein through which fuel gas is supplied to the anode (22); a sealing part (16) disposed around the gas diffusion layer for preventing leakage of the fuel gas to the outside of a single cell (10); a gas supply part (52) for supplying the fuel gas; and a first fuel gas supply flow passage formed by a gap between at least a part of a periphery of the gas diffusion layer (15) and the sealing part (16) for supplying the fuel gas supplied from the gas supply part (52) to the gas diffusion layer (15).

Abstract: A collector plate (14) is connected to an output terminal (16). The collector plate (14) is made such that heat capacity per unit area of a neighboring region (14A) thereof, which is near to a portion where the output terminal (16) is connected, is different to the heat capacity per unit area of other regions (14B, 14C). More specifically, the other regions (14B, 14C) are formed such that the heat capacity per unit area thereof is smaller than that of the neighboring region (14A).

Abstract: A fuel cell having a stack structure is provided. The fuel cell includes plural unit cells each of which includes an anode and a cathode which are provided on both sides of a predetermined electrolyte membrane, and a catalytic layer which is provided in at least one of the anode and the cathode, and which supports a catalyst for promoting an anode reaction or a cathode reaction, the plural unit cells being stacked to form a stack structure. In the fuel cell, the plural unit cells include a unit cell including a catalyst layer supporting a catalyst which is different from catalysts supported by catalyst layers of other unit cells in at least one of type, weight, and specific surface area.

Abstract: A camera is provided that includes a camera housing and a TFT panel, which permits verification of a formed image, located on the back of the camera housing. A strobe unit and an electronic viewfinder unit are located in the upper part of the camera housing. The electronic viewfinder unit has a unit body including: a TFT panel permitting viewing of an object image; an eyepiece opposed to the back of the camera housing and used to view the object image displayed on the TFT panel; and a prism serving as an optical path conversion member that bends by a predetermined angle light emitted from an object image displayed on the TFT panel so as to route the light to the eyepiece, and adjoining the TFT panel and the eyepiece.

Abstract: A camera in accordance with the present invention has a TFT panel, which permits verification of a formed image, located on the back of a camera housing. A strobe unit and an electronic viewfinder unit are located in the upper part of the camera housing. The electronic viewfinder unit 13 has a unit body including: a TFT panel permitting viewing of an object image; an eyepiece opposed to the back of the camera housing and used to view the object image displayed on the TFT panel; and a prism serving as an optical path conversion member that bends by a predetermined angle light emitted from an object image displayed on the TFT panel so as to route the light to the eyepiece, and adjoining the TFT panel and the eyepiece. This results in a small-sized electronic viewfinder unit. Eventually, the camera can be designed compactly and thinly.

Abstract: A switch operating unit for a camera is assembled in the switch supporting frame of the front cover thereof and provided with an inner button, an outer button, and a dial for switch operation. Under the buttons and the dial, there is provided a metal supporting plate for supporting same. Under the supporting plate, there is provided a flexible printed circuit (FPC). Since the contact of the supporting plate is in contact with the ground pattern on the FPC, even when static electricity is generated with or applied to those buttons or the dial, such static electricity is directed to the ground through the supporting plate. Thus, the electronic circuit element mounted on the FPC is protected against static electricity.

Abstract: A lens barrel assembly includes a lens barrel and a lens hood detachably mounted on the lens barrel. A lens barrel includes a mounting threaded portion and three guide rails at three circularly equally spaced positions around the lens barrel. Each guide rail is provided with a forward latch and a rearward latch. The lens hood is constructed of an elastically deformable member, and has a notch to be engaged with the rail. The lens hood is in sliding engagement with the outer circumference of the lens barrel, and is movable between a retracted position and a photographing position. At each position, the lens hood is locked by the respective latch. The lens hood is easily shifted to the photographing position or to the retracted position along the lens barrel, and is also easily attached to and detached from a camera.

Abstract: A camera comprises a fixed lens barrel including a moving lens barrel movable to a collapsed position for non-photography and to a thrust position for photography, and a lens cover capable of pivoting with support shafts, which lie parallel to a plane substantially perpendicular to the optical axis of a photography lens, as a center so as to move to a closed position at which at least part of the face of the photography lens is shielded and to an open position at which the face of the photography lens is exposed. When the lens cover is open, if an external force is applied in a direction in which the lens cover is further opened, the lens cover comes off from the support shafts. The support shafts are formed with two shaft members whose distal portions are formed with tapered surfaces and which are constrained to move in directions in which they are separated from each other. The support shafts are mounted on a member which allows the support shafts to move along the optical axis of the photography lens.

Abstract: A camera comprises a fixed lens barrel including a moving lens barrel moveable to a collapsed position for non-photography and to a thrust position for photography, and a lens cover capable of pivoting with support shafts, which lie parallel to a plane substantially perpendicular to the optical axis of a photography lens, as a center so as to move to a closed position at which at least part of the face of the photography lens is shielded and to an open position at which the face of the photography lens is exposed. When the lens cover is open, if an external force is applied in a direction in which the lens cover is further opened, the lens cover separates from the support shafts. The support shafts are formed with two shaft members whose distal portions are formed with tapered surfaces and which are constrained to move in directions in which they are separated from each other.

Abstract: In a camera according to the present invention, a parallax correction indicator for normal-size photography and a parallax correction indicator for panorama-size photography, which are formed on an image formation plane of a finder optical system, are separately displayed in a finder image display screen set in N photographing mode and in a finder image display screen set in P photographing mode. Therefore, using the camera or the present invention, the finder display will not be complicated but be easy to see during N size photography and panorama-size photography alike. This reduces occurrence of a photographic error.

Abstract: A photographic camera capable of switching the size of a photographic image includes a photographic image size information display device for displaying information on the size of a photographed image on a tongue portion of the film and/or a film cartridge in which the film is loaded. The photographic image size information display device includes a device for printing a printing type in accordance with the photographic image size, and a marking device for making a mark using a laser. Information on the photographic image size can be displayed automatically by this camera using these devices. As a result, no special inconvenience is given to a photographer, and the photographic image size can be reliably recognized in a processing laboratory.

Abstract: The picture-format switchable camera of the present invention is fabricated with a photographic optical system which, in this invention, is a photographic lens; a display unit portion having a lamp light source, a reflection mirror, a condenser lens, and a liquid crystal display; and a mechanical portion, for switching the image plane, having a mask for switching the image plane while retaining an objective lens of an image-forming optical system for inscribing data and a total reflection mirror, and a mask B located in the position facing the mask A; wherein a data-inscribing operation can form the image of the inscribing data on a film by moving the data-inscribing optical system such as the objective lens being interlocked with the up-and-down movement of the mask. Accordingly, an image of the inscribing data can be formed in the predetermined position in accordance with the switched picture format.

Abstract: A camera wherein the photographed picture size can be switched and is formed mostly of a magnification variable finder optical system, a photographed picture size switching mechanism and a finder visual field frame switching mechanism. When the picture size is switched by operating the photographed picture size switching mechanism, the finder magnification will be altered to a magnification corresponding to the picture size through a finder cam as operatively connected with the operation and at the same time the finder visual field frame will be also altered in conformity with the finder magnification and picture size. According to this camera, for example, even if the picture frame becomes narrow, the finder magnification will be elevated by switching the picture size and further the image will be made easy to observe by expanding the finder visual field frame.