Abstract: A D/A converter performs a D/A conversion on digital light quantity indication data outputted from a CPU to generate an analog light quantity indication signal. The analog light quantity indication signal thus generated is supplied to both a power supply circuit and a light quantity control circuit comprising a photometric sensor, an integration circuit, and a comparison circuit. The light quantity control circuit outputs to a flash light emission circuit a light emission stop signal at the time point when the integrated quantity of light reaches a threshold according to the light quantity indication signal.

Abstract: In a camera wherein a lens cap is detachably attached there are provided first and second photometric sensors on a lens barrel and the camera main frame, respectively. It is detected in accordance with the photometric values by the first and second photometric sensors whether the lens cap is mounted. According to the camera, it is possible to detect with great accuracy whether the lens cap is mounted, with a standard type lens cap.

Abstract: The electronic device of the present invention comprises a chassis, a printed circuit board mounted to the chassis and having circuit patterns formed thereon and a protective element connected onto the circuit patterns which protective element is for attenuating a surge voltage, and screws for holding the printed circuit board on the chassis, wherein the protective element is connected to the chassis through any of the screws.

Abstract: The heat radiating structure of an electronic device according to the present invention comprises upper and lower shielding cases, a printed circuit board disposed between the upper and lower shielding cases, and a heat radiating member mounted to the board to absorb and radiate heat which is generated from a heat generating component. Heat conduction members formed of an insulating material are disposed respectively on upper and lower end sides of the heat radiating member so as to be abutted against the upper and lower shielding cases.

Abstract: An auto-focus camera performs a focusing and a photometry when a shutter button is half depressed in an auto-focus mode. In this case, when an MF button is depressed, a result value of the focusing is held as long as the MF button is depressed even if the shutter button is released. When the shutter button is depressed again, only the photometry is performed. On the other hand, when the MF button is depressed in a manual focus mode, an object distance can be set by an UP/DOWN dial which is also used for setting various kinds of photographing items. The MF button is used for maintaining an AF lock, and is used for instructing the setting of the object distance in the manual-focus mode.

Abstract: In a camera of the present invention, when a shutter button is depressed half, a focusing and a photometry are executed. If the shutter button is held in a state of being depressed half, the results are retained. In this case, if an MF button is depressed, the photometry result is retained while the MF button 48 is being depressed, even if the shutter button is released. When the shutter button is depressed half again, only the photometry is performed.

Abstract: A distance measuring apparatus according to the present invention comprises two types of distance measuring units, which are a first distance measuring unit of the active method for receiving reflected light of measuring light returning from an object and performing distance measurement based on a focused position thereof, and a second distance measuring unit of the passive method for receiving the natural light reflected by the object through two optical systems and performing the distance measurement based on two optical images thus obtained. The apparatus further has a luminance determining unit for determining a luminance of the external field from a photometry result, and a distance selecting device for selecting and outputting either one of distance measurement results obtained by the first distance measuring unit and second distance measuring unit as a proper distance value, based on the luminance of the external field determined by the luminance determining unit.

Abstract: An UP/DOWN dial is used with at least one of switches including a back cover switch detecting whether the cover switch of the camera is opened or closed, so as to also serve as a switch for driving a feed motor by the manual operation. As a result, the number of switches can be reduced. That is, the switch for driving the feed motor by the manual operation is used only when the film is set in the camera (only when the back cover opens). Therefore, if the cover switch detects that the back cover opens, the UP/DOWN dial is operated regardless of the currently-set mode, so that the feed motor can be driven.

Abstract: A distance measuring apparatus includes distance measuring units of the active and passive methods, and a distance-value selecting circuit for selecting and outputting one of distance measurement results obtained from these distance measuring units. When a self-timer mode is set, distance measurement of the active method is inhibited, and distance measurement is executed by only the passive method. When the power supply voltage is lower than a predetermined voltage value at which distance measurement can be properly executed by the active method, distance measurement by the active method is inhibited, and distance measurement is executed by only the passive method. Therefore, erroneous distance measurement can be prevented, and distance measurement having high reliability can be performed.

Abstract: A distance measuring apparatus uses both active and passive distance measuring methods. A preferable distance measuring method is selected based upon the luminance of the field and the distance to the object unless a focus lock switch is switched. When the focus lock switch is switched, then a distance measurement using the active distance measuring method is selected.

Abstract: In a distance measuring apparatus, a light-detecting portion in a trigonometric distance measuring apparatus using a passive method is also used as a light-detecting portion for photometry processing. Thus, the luminance range for distance measurement is widened. The distance measuring apparatus includes two light-detecting portions arranged in correspondence with two optical systems. Correction filters for luminous efficacy correction is arranged in the optical paths of each optical system covering halves of the corresponding light-detecting portions.

Abstract: A lens cap in a camera is shaped so as to cover a distance measuring optical system when it is mounted on a taking lens. A photodiode array as a light receiving element for measurement of distance is utilized to obtain a luminance level of the light incident thereto, and it is compared with a luminance level obtained through a light receiving element for photometry. If a difference between the two luminance levels is large, a predetermined cap alarm process is carried out as determining that the lens cap is mounted on the taking lens. Thus, photography is surely prevented in a mounting state of the lens cap.

Abstract: There is provided a distance measuring apparatus capable of avoiding a situation in which the distance measurement time is prolonged. This apparatus executes distance measurement of an active method and distance measurement of a passive method. When a determining portion detects that the distance measurement of the passive method using a large number of photodiodes exceeds a predetermined time, a distance-value selecting circuit selects the distance measurement result of the active method as a distance measurement value.

Abstract: A distance measuring apparatus for measuring a distance to an object, which comprises an active distance measuring unit, a passive distance measuring unit, a parameter determining unit, a memory and a distance-value selecting circuit. The memory stores a distance measurement value look-up table and a parameter look-up table. The distance-value selecting circuit outputs an active distance measurement value or a passive distance measurement value as a distance to the object on the basis of first type active and passive distance measurement points picked up from the distance measurement value look-up table and second type active and passive distance measurement points picked up from the parameter look-up table.

Abstract: A camera is of a type using the 120 size of roll film or the 220 size of roll film, which is so arranged that the height of a pressure plate on a back lid is changed over depending upon a type of a used film. A reflection-type photosensor is provided in the camera body, whereby a state of a lock mechanism of the back lid is detected. A second reflective plate is mounted on the pressure plate, and the second reflective plate reflects light from the photosensor when the back lid is in a lock state. A reflecting position where the light from the photosensor impinges is changed between reflective portions depending upon the height of the pressure plate. Since reflectivities of these reflective portions are different from each other, the height of the pressure plate, that is, the type of the used film can be determined by analyzing an output from the photosensor receiving the reflected light from the second reflective plate.

Abstract: A distance measuring apparatus according to the present invention comprises two types of distance measuring units, which are a first distance measuring unit of the active method for receiving reflected light of measuring light returning from an object and performing distance measurement based on a focused position thereof, and a second distance measuring unit of the passive method for receiving the natural light reflected by the object through two optical systems and performing the distance measurement based on two optical images thus obtained. The apparatus further has a luminance determining unit for determining a luminance of the external field from a photometry result, and a distance selecting device for selecting and outputting either one of distance measurement results obtained by the first distance measuring unit and second distance measuring unit as a proper distance value, based on the luminance of the external field determined by the luminance determining unit.

Abstract: A source voltage monitor for a photographic camera is adapted to determine, prior to release, whether the source voltage is at a level sufficiently high for effective release for exposure. The monitor uses a predetermined reference voltage for the comparison, which voltage is selected independently of the selected mode of photographing. According to the invention, the source voltage is checked prior to release with a lens barrel driving circuit and/or a shutter blade driving circuit energized, depending on the selected mode of photographing. In the preflash mode, for example, both the lens barrel driving circuit and the shutter blade driving circuit are energized during the source voltage check. In low luminance automatic strobe discharge mode, only the lens barrel driving circuit is energized during the source voltage check.

Abstract: In an apparatus for suspending from a quartz rotary shaft, a glass article to be heat treated in a heating furnace so as to support the glass article, a slot is provided for receiving a cylindrical projection formed at an upper end of the glass article, the slot has an elliptical cross section and is formed at a lower end of the rotary shaft. A pin hole for securing the glass article to the rotary shaft, which is formed on the rotary shaft along a minor axis of the slot; wherein a clearance between a peripheral surface of the slot and that of the cylindrical projection along the minor axis of the slot is set to not more than 0.2 mm, while a clearance between the peripheral surface of the slot and that of the cylindrical projection along a major axis of the slot is set to not less than 0.4 mm. An apparatus for supporting a glass article including first and second dummy rods and a coupling member is also provided.

Abstract: A multi-beam type rangefinding method and device uses three LEDs arranged along a line perpendicular to a base line, and a PSD for receiving light reflected from three measurement regions of a photographic scene. In the gain determining procedure, a selected LED emits light at least once. In the rangefinding procedure, it emits light a plurality of times. Light reflected from an object is received by the PSD which outputs two channel signals. The two channel signals are amplified by two gain control amplifiers which are adjusted to have the same gain. The gain is adjusted to be an optimum value for the two channel output signal levels. Upon changing the gain, light projection by a selected LED is stopped until the output of each gain control amplifier becomes stable. If one of the two channel output signals saturates during the rangefinding procedure, the light projection/measurement is repeated at the same gain after a lapse of predetermined delay time.

Abstract: An input system for photographic cameras is provided with a plurality of input switches. The input system includes a matrix input circuit having a plurality of inputs corresponding to a plurality of outputs. A state detector scans key signals output from matrix input circuit at predetermined time intervals and detects states of respective switches provided in the camera so that the camera may operate according to these states. The time interval at which the key scan signals are output is adjustable depending on a state of a main switch. Specifically, the time interval may be relatively long when the main switch is in an OFF state and relatively short when the main switch is in an ON state. More specifically, when the main switch is in the ON state, the time interval of key scan should be adjusted relatively short so that the camera may rapidly operate in response to the states of the respective switches because the camera is ready for photographing in this state of the main switch.