摘要:
An exposure control device for a single lens reflex camera has an exposure calculating mechanism for determining the amount of exposure in accordance with desired shutter time, aperture value, film sensitivity and brightness of the object to be photographed. The exposure calculating mechanism is carried along one external wall of a casing for the reflex mirror of the camera.
摘要:
An exposure control device for a camera, having a first light receiving element for sensing light beams reflected from a film surface and a second light receiving element for sensing light beams from an object before taking a photograph. In this arrangement an auxiliary diaphragm, which is opened as a shutter is closed and is closed as the shutter is opened, is provided in front of the second light receiving element. The first and second light receiving elements are connected in parallel between input terminals of an operational amplifier for the light measuring. Accordingly, an exposure control with a high degree of accuracy is effected based on an output of the light measuring operational amplifier.
摘要:
A leak current suppressing printed circuit board in which the input circuit is so designed that between the input terminals a light sensing photoelectric converting element operating in the current mode is connected. The input is guarded by means of the circuit net, whose potential is same as that at the input terminal of the inverting input circuit or the non-inverting input circuit of the high input impedance operation amplifier.
摘要:
The present invention relates to a light measuring circuit consisting of an operational amplifier, a feed back path connected with said operational amplifier, a photo voltaic cell and a switching circuit for bringing the input terminals of said operational amplifier to the same potential at the time light measurement is commenced. By means of this switching circuit connected to the light measuring circuit the delayed response of the light measuring circuit due to the stray capacitence existing between the input terminal of the operational amplifier and ground is remarkably improved.
摘要:
The present invention relates to an exposure control apparatus for a camera which is so designed that the output terminal of the light measuring circuit of the brightness of the object to be photographed having a photo electric transducing means is connected to one input terminal of an operation amplifier. The output of the photographing information setting circuit, having a variable resistance means for setting other photographing informations than the information of the brightness of the object to be photographed, is connected to the other input terminal of the above mentioned operation amplifier. This is done in such a manner that proper exposure conditions can be obtained by means of the output of the exposure control circuit connected to the output of the above mentioned operation amplifier. Each input signal to the operational amplifier is adjusted by a bias signal which is controlled in accordance with ambient temperature conditions.
摘要:
A filter for compensation of spectral sensitivity is provided in front of a light receiving element through a light shielding tube. A light source emitting such light as having wave length characteristics which fall within a sensitive wave length zone of the light receiving element yet fall outside of transmitting wave length zone of the filter is provided between the filter and the light receiving element. Light from outside irradiates the light receiving element through the filter while light from the light source is so controlled as irradiating the light receiving element but not leaking through the filter to outside, so that the light from the light source can irradiate the light receiving element without any relationship with the irradiation of outside light on the light receiving element.
摘要:
An exposure control device in which the output of a light measuring circuit which produces an electrical signal corresponding to the brightness of an object is compared with an output of a level signal circuit which produces an electrical signal of a predetermined level. When the compared value reaches a predetermined value, a flash circuit is made ready to flash, whereby the shutter time is changed over to a predetermined time suited for a flash photography and the flash circuit is made to flash in association with the shutter operation and the shutter is controlled with a constant time.
摘要:
In a camera provided with a day-light exposure range and with a flash exposure range, an automatic exposure control system for controlling the iris of the camera in accordance with a computed exposure value and a preselected shutter time is associated with a flash exposure time range bracketing device in order to insure that the formation of a correct flash exposure aperture is effected with automatic selection of one of the bracketed exposure times despite an accidentally incorrect setting of the shutter dial of the camera which may be encountered particularly when the day-light exposure range is to be left for the flash exposure range without the necessary manipulation of the shutter dial therefor. The bracketing device of the present invention comprises three timing circuits in combination with a selector responsive to the position of the shutter dial for selecting either the first, or the second, or the third timing circuit for cooperation with an electronic switch controlling the period of actuation of the camera shutter when the shutter dial is set either within, or on the faster side of, or on the slower side of a possible flash exposure time range respectively, whereby the resultant actuation period is equal to either the shutter time preselected on the shutter dial, or the faster limit of, or the slower limit of the flash exposure time range respectively.
摘要:
A distance detecting device comprising radiation projecting means for projecting a radiation beam; radiation sensing means which is disposed away from the radiation projecting means with a given length and is arranged to receive a reflected radiation beam coming from an object whose distance is to be detected as the radiation beam is projected from the projecting means; and movable means for relatively varying the incident condition of the projected radiation beam onto the sensing means. The distance to the object is found either by the position of the movable means or by the amount of displacement thereof which occurs at a time point at which the sensing means optimally receive the reflected radiation beam coming from the object in the process of relatively varying the incident condition of the projected radiation beam onto the sensing means. In the incident condition varying process, the output signal of the sensing means and a delayed signal which is obtained by delaying the output signal a predetermined period of time are compared with each other to detect a time point at which the output signal of the sensing means has reached its peak level and, accordingly, to detect when the sensing means optimally receive the reflected radiation beam coming from the object.
摘要:
The present invention relates to an exposure meter circuit of a camera with a matching network for a flash device with which camera auxiliary light photography can be carried out the flash device presents a detecting output terminal of a detecting network for detecting the level of the stored energy of an energy storing means provided in the flash circuit of the flash device, a voltage supply terminal for supplying the operation voltage to the detecting network and a synchronizing terminal for triggering the flash device. With this camera, daylight photographing can also be carried out without a flash device. The exposure meter circuit is characterized in that in the exposure meter circuit a current source is included for the exposure meter. A first switching means is connected with one electrode of the current source. Grounding of the current source occurs in functional connection with the switching of the flashlight photographing over to the daylight photographing. A second switching means is connected in the exposure meter circuit and switches off the light receiving means, where in the case of the flash photographing, the voltage is given to the supply terminal from the current source for the exposure meter by means of said first switching means so as to operate the detecting network. In the case of the daylight photographing, the light receiving means is connected in the exposure meter circuit by means of the first and the second switching means so as to bring the detecting network out of operation by grounding the current source.