Minolta Camera Kabushiki Kaisha

Yoshiharu Ohta

Hiroshi Hosomizu

Shinji Tominaga

Makoto Kamiya

Katsuhito Akagi

Haruyuki Nagano

Mikio Naya

Masataka Hamada

Kohtaro Hayashi

Masayoshi Sahara

Kazuo Kimura

Motonobu Matsuda

Yukio Maekawa

Keiji Yamazaki

Masatoshi Yoneyama

Ichiro Yoshiyama

Takeo Hohda

In a telescope, the adjustment order is limited so that dioptric power adjustment is made after adjustment of a distance between a pair of optical systems is completed. A pupil distance and a dioptric power correction amount are stored in a memory for every user. When a user uses the telescope, his or her pupil distance and dioptric power correction amount are read out from the memory to automatically make adjustment.

Binocular system with automatic diopter power adjustment

In a telescope according to the present invention, defocus amount of an optical system constituting the telescope is calculated; whether or not the defocus amount is within a predetermined in-focus range obtained from a focal point adjusting ability of human eye is discriminated; and when the defocus amount exceeds the in-focus range as a result of the above discrimination, the optical system is driven. The optical system is driven in a shorter time than a time required for removing a defocus by human eye.

Telescope

An automatic electronic flash device for use with a camera includes a flash tube carried by a housing. A battery is carried by the housing as a source of electric supply. A capacitor is connected to the flash tube to fire it when discharged. A circuit is used to automatically adjust the amount of light emitted from said flash tube upon the firing of the tube. The circuit includes a light receiving element arranged to receive light reflected from a photographic object upon the firing of the tube. The information of distance from the camera to an object to be photographed is fed to the circuit as a function of the amount of light received. A switch is connected to the circuit to cause it to vary the amount of light emitted from the flash tube. A calculator enables calculation of a plurality of combinations of aperture settings and distance setting in response to a film speed setting, so that selection of a desired film speed will result in indication of a desired aperture setting and distance setting. Light emitting diodes are disposed adjacent to the calculator for indication of one of the combinations calculated by the calculator. Another switch connects one of the light emitting diodes to the battery for selective energization thereof in association with the switching of the above switch connected to the circuit.

Automatically controlled electronic flash device

A semiconductor switching element is connected in series with a flash tube to stop emission of flash light therefrom during operation of the flash tube. A first and a second integrating circuit are parallelly arranged to be connected either alternatively, or both together, with the switching element. The first integrating circuit integrates photo-current generated by a photocell receiving light from an object illuminated by the flash light, and the second integrating circuit integrates current that is manually adjustable. When both integrating circuits are connected with the switching element, the switching element is turned off by that integrating circuit which first reaches a predetermined trigger level.

Electronic control circuitry for terminating flash output

In a system where a single power source battery is commonly used for the oscillation circuit of an electronic flash device and for another circuit, such as a control circuit for energizing a light source for a data recording for a given period of time, the operation of the oscillation circuit is interrupted by a semiconductor switching device in response to a firing of the flash tube of the flash device. The oscillation circuit interruption continues for a predetermined period during which the aforesaid another circuit is operated from the battery. To this end, the semiconductor switch may be controlled by a delay circuit.

Operation control circuitry for electronic flash devices

In a camera provided with a data or auxiliary information recording device and an electronic flash device for illuminating an object scene to be photographed, another electronic flash device is provided for the illumination of data to be recorded. A single power source is used for both the above two electronic flash devices and an automatic exposure control circuit. To avoid a voltage drop of the power source during the operation of the exposure control circuit due to charging of the main capacitor for the electronic flash for the scene illumination, a power supply switch for the main capacitor charging circuit is manually closed independently of the camera exposure operation. A capacitor for energizing the electronic flash for the data illumination is charged in conjunction with the camera release operation before the camera exposure is commenced.

Power supply control device for cameras

A device for visually indicating the camera incident light conditions and the readiness of an associated photoflash network on a single element includes an incandescent indicating lamp connected through parallel transistors to a current source. One transistor is controlled in response to the light incident on a photoconductor to apply a steady current to the lamp when the photoconductor incident light is below a predetermined level. The other transistor is controlled by a relax action oscillator including the photoflash triggering capacitor to apply an intermittent current at a visually perceptable frequency to the lamp when the charge on the photoflash main capacitor is at least at a predetermined value. The lamp is advantageously located as to be visible through the camera view finder.

Device for indicating light and photoflash circuit conditions in camera

In an electronic flash device, wherein electrical energy stored by a main capacitor and an electronic flash tube is fired by the stored energy, a relaxation oscillator is adapted to oscillate when the main capacitor is charged to a given voltage level, which is a condition for completion of preparation for flash tube operation. The relaxation oscillator includes a capacitor, a glow discharge tube, and a resistor and the oscillation thereof causes intermittent glow discharge through the glow discharge tube for indicating the completion of preparation for flash tube operation. The electronic flash tube is triggered to emit a light flash by the stored energy of the relaxation oscillator capacitor. Excitation of the flash device, even with a power supply switch open, is prevented by isolating the main capacitor from the trigger capacitor and also from the glow discharge tube to also prevent an indication of flash preparation. The trigger capacitor is also discharged through the resistor to prevent actuation of the flash device should the flash synchro switch be closed with the power supply switch open.

Electronic flash devices

Camera exposure control circuitry for automatically controlling exposure time or the diaphragm aperture in accordance with scene brightness, is provided with an indicating device for indicating exposure conditions to be determined by the control circuitry. In response to a rectangular wave signal produced by a photoflash device upon completion of charging of the main capacitor thereof, the control circuitry is set to provide a proper exposure condition suitable for flash photography. The indicating device intermittently energizes one of a plurality of indicator elements that indicates the proper exposure condition, in response to upper level portions of the rectangular wave signal. An exposure control magnet is controlled by two parallelly connected transistors, one being responsive to the output of the control circuitry and the other being responsive to the signal from the photoflash device.

Growing community of inventors

Izumi, Japan

Yoshiharu Ohta