摘要:
A shutter control circuit which normally responds to ambient light switches automatically to a flash mode in response to a charge signal from a flash unit. The light flash eliminates the charge signal. To prevent the absence of a charge signal from returning the shutter to daylight control, a shutter closing signal is generated before a flash synchronizing contact is closed and hence before the charge signal ends. However shutter closing action is then started only after a delay that provides time for the flash to occur when the shutter is fully open.
摘要:
An electronic flash apparatus is provided with a display element positioned in the view-finder of a photographic camera so that the operator is immediately aware if the flash tube has been fired in response to the closure of the synchronous switch. The light emitting operation of this display element is controlled by use of a signal generator arranged to be responsive to the occurrence of discharge through the flash tube of the flash apparatus. With this apparatus, therefore, the operator may rely upon the appearance of this display element to insure that the firing is effected by the flash apparatus even when the object-to-camera distance is relatively small.
摘要:
The present invention relates to a safety device for exposure amount control equipment consisting of a camera and an electronic flash device, including a detecting circuit for detecting the charge voltage of the storage capacitor of the electronic flash device and the voltage of the power source and producing two different electrical signals in accordance with the detected voltages so as to prevent flash light photography with improper exposure amount and a lock member for preventing the movement of a shutter release mechanism of the camera in accordance with the electrical signal produced in the detecting circuit when the detected voltages are lower than a certain determined value.
摘要:
A voltage detecting means is provided in a flash lamp firing circuit for detecting the attainment of the voltage of a storage capacitor to a satisfactory lamp firing voltage level to assure that a photographic camera associated with the flash lighting unit operates in a flash exposure range switched from a daylight exposure range only when a sufficient voltage is available to fire the lamp at the time of striking of the lamp. In one embodiment, the detecting means comprises two transistorized circuits having output terminals one of which is connected to the gate lead of a SCR in a discharge circuit of the lamp, and another output terminal which is arranged to be connectable to a light-emitting diode of the camera and therefrom connected to the gate lead of an electronic change-over switch for selection of the operating ranges of the camera, the light-emitting diode being arranged to be visible from the outside of the camera so that the operator is immediately aware if the storage capacitor voltage has attained the satisfactory firing level.
摘要:
The present invention relates to a shutter time control circuit of the type in which the shutter time is changed over into a predetermined value for flash light photography in response to a flash charge completion signal from the flash light device. In order to eliminate the shortcoming of the conventional shutter time control circuit of this type, in that when the shutter time is changed over into the value predetermined for flash light photography predetermined shutter time is memorized in a memory capacitor for controlling the shutter time in accordance with the value memorized after the charge completion signal has disappeared.
摘要:
A self-adjusting electronic flash is attached to an interchangeable lens camera having a shutter-priority exposure control. For flash operation, aperture information suitable for electronic flash and the film sensitivity is automatically conveyed to the camera's diaphragm control. Thus the aperture can be automatically adjusted for flash as well as daylight operation.
摘要:
The time period necessary to charge a current-to-light convertible energy storing capacitor to a certain voltage is reduced as compared with prior art devices. The energy storing capacitor is connected across a flash tube and switching element series-connected with each other. The switching element is provided with a control circuit, responsive to the voltage of the storage capacitor decreasing to a level at which the flash tube is stopped from producing flash light, for producing a terminating signal by which the switching element is brought into the open or non conducting state. With this arrangement, it is made possible to prevent complete discharge of the electric charge stored in the storage capacitor from occurring, thereby providing the advantage of saving a good fraction of the charging time period which would be otherwise necessary when the storage capacitor is completely discharged to zero voltage.
摘要:
An adapter matches an electronic flash unit with a single terminal carrying diaphragm and charge data to a camera having separate terminals for these data. A second adapter matches a flash unit having two terminals for diaphragm and charge data to a camera in which these data pass through a single terminal. Circuitry in the adapters combine or separate the data as needed.
摘要:
A selector circuit interrupted by an electrical signal from an attachment selectively mounted on the camera body and is connected in the light receiving circuit as well as the exposure determining circuit provided in the camera. When the above mentioned unit is mounted on the camera the exposure determining circuit provided in the camera is automatically connected from the light receiving circuit to the output terminal of the unit by means of the selector circuit, so as to receive the exposure value signal on the unit and set the exposure value corresponding to the exposure value signal.
摘要:
A camera system is composed of a flash and a camera in which the diaphragm and shutter time control as well as the indicating mechanism are automatically switched into a flash mode in response to the charge accumulation completion signal from the electronic flash discharge device.