Canon Kabushiki Kaisha

Zenzo Nakamura

Takashi Uchiyama

Tokuichi Tsunekawa

Shohei Ohtaki

Masanori Uchidoi

Hiroshi Aizawa

Yukio Mashimo

Tetsuya Taguchi

Tadashi Ito

Syohei Ohtaki

Susumu Kozuki

Shyohei Ohtaki

Masayuki A Suzuki

Ryoichi Suzuki

Hideo Yokota

Nobuaki Sakurada

Michio Hirohata

Takehiko Kiyohara

Mutsuhide Matsuda

Yoji Sugiura

Youichi Okuno

Mutsunobu Yazaki

Yoshiyuki Takishima

Noriaki Sanada

Keiko Kondo

Goro Hasegawa

Naoki Nagase

Osamu Okubo

An exposure control system for daylight and flash photography. In the flash mode with computer flash light device, the system accommodates for a variation in the otherwise fixed parameter of diaphragm aperture by taking into account the camera-to-subject distance. In one embodiment of the invention, the diaphragm value and the integrated flash light are varied with distance at equal rates to each other, reaching the maximum possible values simultaneously at a distance twice as long as that when the diaphragm is fixed. In another embodiment, these variables are increased one at a time, reaching the maximum value, after which the other is increased to effect an equivalent result.

Flash photographic exposure control system

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.

Flash lighting unit for a camera

An adapter device for interconnecting a light adjusting flash device and a camera. The adapter device includes a first terminal for connection to a charge completion signal circuit in the flash device, a second terminal for connection to a mode selection circuit in the camera and a transistor which is turned on in response to a charge completion signal to change the electrical condition at the second terminal to operate the mode selecting circuit to select the flashlight mode. The adapter device further includes a third terminal which is connected to an aperture signal forming circuit in the camera and is connectable to the second terminal to transmit a flash aperture value signal to an aperture control circuit in the camera.

Adapter device

An indicating device of computer type electronic flash apparatus has a plurality of display members representing respective limited distance ranges for correct exposure of an object to be photographed. Each of the display members corresponds to a respective set diaphragm value. The indicating device further includes a plurality of indicating marks provided on the same plane of said display members and corresponding to respective set diaphragm values. With this device, it is possible to be aware of the proper distance range satisfactorily.

Indicating device for computer type electronic flash apparatus

An adapter device for use with a versatile light adjusting flash illuminating device of the reflected light reception type or a slightly reformed flash illuminating device receives a light emission preparation signal of the flash illuminating device, for example, the charging completion signal of a main capacitor or a main switch ON signal and forms an exposure control signal for an exclusive camera. The adapter device is provided with a shoe for accommodating the leads of the flash unit and with a foot for connection with the leads of the exclusive camera.

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.

Flash camera system with daylight cutout control

The present invention relates to a device for flash light photography and, more particularly, to a device for flash light photography for adjustable light stroboscope. A major feature of the present invention is that the adjustable light condition of the stroboscope is rendered to be adjusted, based on the film speed and diaphragm value, independently of each other. Thus, when the film speed is made high, the responsive distance for light adjustment is elongated.

Flash exposure control system

An automatic exposure control system for cameras of flash photographic capabilities which is switched to either of the daylight or the mode depending upon whether or not a storage capacitor across which a flash tube is connected is sufficiently charged. The system comprises first and second computers for deriving daylight and flash exposure aperture values respectively, a diaphragm control circuit selectively receptive of the outputs of the computers through a first switch, first and second timing circuits for providing daylight and flash exposure times respectively, and a shutter control circuit selectively receptive of the outputs of the timing circuits through a second switch. The system is characterized in the use of a single mode selection actuator which is common to the first and second switches and which causes an automatic selection of the flash mode when the camera release occurs after the attainment of the voltage of the storage capacitor to the normal firing level. Thus, it is made possible to prevent occurrence of an event where the flash tube is actuated for firing with the simultaneous occurrence of selection of the flash exposure time, while the daylight exposure aperture remains effective, as the storage capacitor voltage reaches the normal firing level at a point in time during the daylight exposure operation.

Camera for daylight and flash photography

The present invention relates to various kinds of the flash light photographic systems consisting of a combination of either of the below mentioned cameras with either of the below mentioned flash light device;

Flash light photographic systems

A photographic data recording device for a camera for photographically recording some data on film together with a photographic image. The device includes a capacitor, a charging circuit for the capacitor which responds to the release of the shutter for commencing charging and an electronic flash device operating in response to the capacitor discharge to illuminate the data. A control device automatically causes the capacitor to discharge electricity to allow the electronic flash device to emit a flash when the charge of the capacitor reaches a preset level of potential and which prevents the capacitor from discharging when the charge is below the preset level of potential. A display lamp may be utilized to indicate when the charged voltage of the capacitor reaches a preset level.

Data printer for a camera

A camera having an electronic flash unit either incorporated therein or removably attached thereto is provided with a flash mode selector and a flash energy supply control switch both arranged to be rendered operative when the shutter cocking lever is pulled from the retracted position to an initial position effective for shutter cocking operation, and, upon detection of occurrence of a lower light value beyond an automatically operating daylight diaphragm aperture range, to be simultaneously closed in automatic response to an actuation of a shutter release trigger in excess of a normal stroke length. This is done while still preventing the shutter from running. When the voltage on a storage capacitor reaches a trigger level for the flash tube in a time interval measuring from the closure of the switch, a flash exposure diaphragm aperture is automatically formed depending upon the flash exposure value and the voltage of the storage capacitor. When the shutter cocking lever is retracted, the switch is opened to prevent accidental consumption of the electrical energy of the power source.

The present invention relates to a light-sensing circuit used in a so-called light regulating type flash device to automatically control the amount of flash emitted. In the present invention, a flash photographing with an appropriate exposure is done, securing such flash amount as providing appropriate exposure always regardless of the position of an object in a photographing frame. This is done by making light-sensing for each of different zones independently using a plural number of light-sensing circuits for stopping the flashing by the output of the one light-sensing circuit reaching a prescribed level of output from the different light-sensing circuits.

Zone responsive, light-sensing circuit for controlling flash

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.

Automatic exposure control camera

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.

Safety device for an exposure amount control equipment

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.

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Urawa, Japan

Zenzo Nakamura