Minolta Camera Kabushiki Kaisha

Seiji Yamada

Yasuhiro Nanba

Mashio Kitaura

Toshio Kobori

Kayoshi Tsujimoto

Shinji Tominaga

Toshinori Imura

Norio Beppu

Yasuzi Kogure

Ichiro Yoshiyama

Hiroshi Ueda

Masayoshi Sahara

Motonobu Matsuda

Keisuke Maeda

Kotaro Yata

An exposure indicating device indicates at the same time a result of average light measurement which measures a light level of a substantial portion of a scene to be photographed, and a result of spot light measurement which measures a brightness at a small portion of the scene. One of the values of the average and spot light measurements is displayed numerically to indicate its absolute value, while the other is displayed as a deviation from the former value.

Exposure indicating device

A focus condition indicating system for use in a camera includes a control signal producer provided in association with an objective lens of the camera for producing a control signal when the objective lens moves past a proper focus position and a sound producer for producing a sound signal upon receipt of the control signal.

Focus condition indicating system for use in a camera

In a multi-mode exposure control device for a photographic camera which automatically controls camera exposure in any desired one of diaphragm aperture priority mode, shutter speed priority mode and program mode, the selection of the exposure control mode as well as the setting of the exposure parameter to be manually determined are effected by manual operation of a single one of a plurality of manual members. A signal selector circuit receives three pairs of diaphragm control and shutter control signals for the three exposure control modes, and selects one of the pairs depending on the last operated one of diaphragm aperture setting, shutter speed setting and program mode selecting manual members. The selected pair of diaphragm control signal and shutter control signal are respectively supplied to diaphragm and shutter control circuits as well as to display devices.

Selection and setting device for camera exposure control

In an exposure control system for a camera having an interchangeable objective lens, a diaphragm mechanism defining the diaphragm aperture, a preset means for presetting the f-number of the diaphragm aperture and a shutter mechanism for effecting an exposure, a light measuring circuit generates an output signal having a level representative of the light from an object to be photographed and a reference signal circuit generates a reference signal having a predetermined level. A programmed signal circuit generates a programmed signal in accordance with the output signal and the reference signal, and an exposure control circuit controls both the diaphragm and the shutter mechanisms such that the diaphragm aperture and the shutter speed have a combination of values commensurate with the programmed signal. The programmed signal circuit includes a variable member having an electric parameter variable in accordance with the number of steps of the diaphragm aperture from the minimum f-number to a preset f-number.

Exposure control system for lens interchangeable cameras

A through-the-lens type automatic exposure control system controls exposure time in accordance with an object light representative signal stored in a storage device prior to a shutter actuation, with respect to exposure time faster than a given value, and in accordance with the output of a light measuring circuit measuring the object light passing through the camera objective and reflected from a film surface, with respect to exposure time slower than the given value. In response to a manual operation, the light signal is stored in the storage device independently of camera release operation, with the exposure time being controlled in accordance with the stored signal regardless of the exposure time.

Exposure control system for single lens reflex cameras

An automatic exposure control system for a single lens reflex camera, of the type wherein diaphragm blades defining a diaphragm aperture are driven in response to a camera release operation to change the aperture in accordance with the light from an object to be photographed (object light) as measured by a light measuring device which has a photoelectric element adapted to receive the object light through changing diaphragm aperture as well as through the camera objective. When the output of the light measuring device reaches or goes beyond a given level, a control device generates an output signal to actuate a first electromagnetic device which stops the operation of the diaphragm blades so that a diaphragm aperture suitable for the object brightness is determined as a function of a set shutter speed and a set film sensitivity. The output signal also serves to actuate a second electromagnetic device which actuates a reflex mirror immediately after the diaphragm aperture determination, with a shutter mechanism being actuated subsequently for film exposure. The shutter may be controlled in accordance with the output of the light measuring circuit which measures the scene brightness through the determined diaphragm aperture.

Control system for single lens reflex camera

A lamp control circuit for energizing a data imprinting lamp in response to an actuation of a flash trigger switch in a camera, for a given period so that data images illuminated by the lamp are imprinted on a film with a suitable exposure. The control circuit includes a series connection of a SCR element and a capacitor, a trigger circuit for applying a single pulse to the control terminal of the SCR element, a capacitor discharge circuit for discharging with a given time constant the capacitor that has been charged through the SCR element, and a switching circuit for energizing the lamp while the terminal voltage of the capacitor is above a threshold level. The trigger circuit has a high input impedance to protect the control circuit from high voltage which otherwise may be applied thereto through a camera synchro terminal to which the input terminal of the trigger circuit is connectable.

Data imprinting lamp control circuit

An automatic focus control camera which includes automatic exposure control means, automatic focus adjusting means, and flash means. These three means are arranged to have a power source in common, and furthermore, the automatic focus adjusting means and flash means are supplied with electric power through an electric voltage boosting circuit which is arranged not to function during an exposure period for taking photographs. Moreover, an electric voltage checking circuit is included for checking a voltage supplied to the automatic focus adjusting means so that the shutter can not be released unless the voltage reaches a predetermined level.

Automatic focus control camera

In a photographic camera having programmed automatic exposure control, a light measuring output is produced by measuring scene light and an exposure value signal is generated in response to the light measuring output. A time value and aperture value signal are automatically varied as a function of the changes in the exposure value signal, which function is adapted to be altered in a predetermined manner by the change in the exposure value signal. The aperture size is determined in response to the size in the aperture value signal and the exposure time is determined in accordance with the time value signal.

Programmed exposure control system for a camera

An auto-focus camera including an automatic rangefinder device for generating a distance signal indicative of the distance between the camera and a target object to be photographed, a timer circuit for generating an output signal a predetermined time after a power switch is closed, to place a lens drive mechanism in an operative condition for repositioning an objective lens assembly of the camera in search of the true focus setting, and a lens arresting circuit including electromagnetic units. Either of the electromagnetic units is operable to arrest the objective lens assembly at a corresponding focal position when energized by the distance signal. The automatic rangefinder device can measure the distance from the camera to the target object independent of the release of the lens drive mechanism.

Auto-focus camera having rangefinder system

A position-to-digital encoder for generating digital signals in the form of binary code in accordance with the relative positions between a pair of brush contacts and a series of contacts arranged in order. The latter contacts are disposed in a row along the path of movement of the brush contacts, with equal pitches and gaps between adjacent contacts. The brush contacts are spaced from each other along their path of movement with such a distance that two brush contacts are in contact with a single one of the series of contacts or with an adjacent two of the series of contacts, respectively. One line extends from each contact to a decoder which generates signals in accordance with which contact or contacts of the contact series is engaged by the brush contacts. The decoder generates different signals in accordance with whether a single or double contact is engaged by the brush contacts so that (2n-1) different signals may be obtained as a function of the relative position between the brush, contacts and the series of contacts, where n is the number of the latter contacts.

Position-to-digital encoder

An exposure meter for use in photography which includes means for measuring brightness at a plurality of places in a scene to be measured for exposure, means for calculating frequency distribution of the brightness which divides brightness value into many stages and counts frequency of occurrence of brightness at each of the stages, and means for calculating, under designated conditions, position whereat film latitude is to be present within the width of the brightness distribution.

Exposure meter

An exposure meter provides a display indicating the brightness of selected portions of a scene to be photographed. In one embodiment, a photometering block including a plurality of light sensitive elements is employed, and there is an automatic fixed display indicating the brightness level of the brightest and the darkest portions of the objective scene together with a display of a median value. Another embodiment employs a spot photometering device with only one light sensitive element, and a display of the brightness level of different portions of the scene selected by the photographer.

Growing community of inventors

Sakai, Japan

Seiji Yamada