Abstract: A light measuring device in which the field of a photometric system is divided into a plurality of areas, and the outputs of these areas are computed based on the one of various formulae which is selected depending on the relative size of the subject image to the total field as the focal length of a photographic lens varies, to obtain an exposure value.

Abstract: A photometric device of the kind obtaining information on the luminance of each of photometric areas defined by dividing a photographing field at least into a middle area and a peripheral area and computing a photometric value on the basis of luminance information obtained from the middle and peripheral areas includes: detecting means for detecting whether the luminance information obtained from the peripheral area exceeds a given upper limit luminance level; and correcting means which is arranged to substitute a specific luminance information value for the luminance information obtained from the peripheral area when the latter is detected by the detecting means to be exceeding the upper limit luminance level.

Abstract: A light measuring device comprises light receiving means arranged to divide a photographing field at least into three areas including a middle area located in the middle of the field, a first outer area located on the outer side of the middle area and a second outer area located on the outer side of the first outer area and to obtain luminance information on each of the areas; luminance difference detecting means for obtaining information of a luminance difference between adjacent areas among the plurality of areas from a plurality of luminance information values obtained by the light receiving means; computing means including photometric value computing circuits equivalent to a plurality of computing formulas each of which including as a function at least one of the plurality of luminance information values obtained by the light receiving means; and selection means for selecting one of the photometric value computing circuits of the computing means which is equivalent to one of the computing formulas on the

Abstract: A light measuring device for a camera comprises a light receiving circuit having a plurality of light receiving portions for seeking an area brightness information of each of at least two areas into which the field of view is divided, including a central area located at a center of the field of view and an outer area located outside of the central area, a discrimination circuit for discriminating whether or not the camera has been set in the fill-in flash mode, and a computing circuit for seeking a measuring light value by a computation formula including at least one brightness information out of the plurality of brightness informations sought by the light receiving circuit as a function, the computing circuit performing the light value computation with a weight on the area brightness information of the outer area when the setting of a flash exposure in the fill-in flash mode has been discriminated by the discriminating circuit.

Abstract: A device for driving an electro-luminescence in which an electrical power source, a coil and a switching means are connected in series to each other. The switching means is time-serially opened and closed by a control unit, and is connected in parallel to the electro-luminescence.

Abstract: A light measuring device having an automatic focus control mechanism including one-shot type focus control means for effecting focus control in one-shot type focus control mode and servo type focus control means for effecting focus control in servo type focus control mode, in which a field to be photographed is divided into a plurality of areas which are subjected to light-measurement, and a control circuit is provided to vary weighting for light-measurement of these divided areas according to the selection of the above-mentioned focus control mode effected by said automatic focus control mechanism.

Abstract: A light pulse detecting device having a photo-transistor whose output is compared with a level to detect incidence of a light pulse thereon. In this device, the photo-transistor is provided with other transistors cascode-connected thereto. For this reason, the capacitance of the emitter-collector path of the photo-transistor becomes equivalently smaller, improving the response characteristic of the light pulse detecting device.

Abstract: The present invention relates to a so-called AE lock device for camera, and more particularly to such device in which as the object brightness is changing rapidly, when the stored value of brightness at the time of the AE lock is later found to give an improper exposure value, either photographer is warned of this, or the AE lock mode is cancelled automatically.

Abstract: The disclosed AD conversion device has an AD conversion circuit for AD converting information corresponding to object brightness and other photographic information in a double integrating system. The integrating time for AD converting the photographic information not corresponding to the object brightness is shorter than the integrating time for AD converting the information corresponding to the object brightness.