Minolta Camera Kabushiki Kaisha

Minolta Company, Ltd.

Minolta Camera Co., Ltd.

Yoshio Yuasa

Kazuhiko Naruse

Nobukazu Kawagoe

Masahito Inaba

Hidetoshi Yasumoto

Nobuyuki Taniguchi

Norio Ishikawa

Yasushi Goto

Ichiro Yoshiyama

Susumu Shirai

Izumi Horie

Toru Kisanuki

A photometric apparatus includes an exposure value calculator for calculating an exposure value based on light data from a photo sensor and an inputted photosensitivity; an exposure value difference calculator for calculating a difference between a calculated exposure value and a reference exposure value; a gamma characteristic provider, which provides a gamma characteristic concerning a relationship between the exposure value difference and a gradation value of digital data; a gradation calculator for calculating, based on the exposure value difference and the gamma characteristic, a gradation value of digital data in connection with an object having the calculated exposure value when the object is photographed at the reference exposure value; and an indicator for indicating the calculated gradation value of digital data in connection with the object.

Photometric apparatus

An exposure meter has both function of an incident light type exposure meter for measuring an exposure value of an object by an incident light to the object and a reflected light type exposure meter for measuring exposure value of the object by a reflected light from the object. A latitude of a film is calculated from the exposure value by the incident light. The exposure value by the incident light and an upper and a lower limit values of the latitude are displayed on a display device. At least one exposure value measured by the reflected light is further displayed on the display device comparably with the latitude.

Exposure meter

An improved light measuring device for measuring flash light is provided, and includes a sensor for measuring the quantity of flash light to produce a flash measuring signal. A starting signal is produced upon a detection of the start of the flash emission to enable the sensor for measuring the quantity of flash light. The light measuring device is kept in an operative condition for a predetermined time period after it is manually turned on so that it is available to detect the start of any flash emission during that time period. A counter can be utilized to set the predetermined time period, and the counter can be reset in response to any light measuring operation.

Light measuring device

An electronic flash device fires one or a pair of flash tube sequentially for continuous shooting photography with a motor driven photographic camera, for substantially continuous illumination or for sequential illuminations at intervals, as well as fire the flash tube a single time for one shot photography. The flash device is provided with a main capacitor and an auxiliary capacitor which selectively energize the flash tube or tubes. The auxiliary capacitor is charged by the main capacitor and discharged to energize the flash tube for a small amount of flash light and short-time restoration of the flash firing circuit. When a pair of flash tubes are employed, they are alternatively actuated for the sequential firing and one of them is actuated for the single time firing. The pair of flash tubes are coupled with each other through a commutation capacitor and switch elements for quick repetition of their firings.

Electronic flash device

An enlarger for copying a film is provided having two modes of operation. A first mode of operation permits preliminary adjustment of the focus of the lens system while the second mode of operation permits an actual exposure, the first mode of operation being inhibited during the actual exposure of the film in the second mode.

Enlarger for use in photography

A light measuring device for use in flash photography, which measures preliminary flash light and ambient light to obtain camera exposure information under a mixture of primary flash light and ambient light, there are provided light measuring means and means for displaying the result of the measurement in such a manner that the desired exposure information of the several positions of the photographic object can be displayed on a common scale so that the effect of the flash light, ambient light and the total light can be recognized in one glance.

An improved light measuring device that is capable of measuring light upon initialization from either a flash of light or a manual switch is provided. A sensor assembly can produce a light intensity signal and a change in the intensity of the light measured can be used to produce a first signal. A second signal can be produced by a manually operable member. A counter can be used to count the number of signals and to produce a preparing signal upon an initial signal counted and a start signal upon a subsequent signal counted. Measurement of the amount of light in the circuit can be initially enabled when the counting means counts the first signal and the actual light measurement can be started subsequently upon the counting means initiating a start signal. Various sequences of producing the pair of signals can be utilized to control the operation of the light measuring device.

An electronic flash device fires one or a pair of flash tubes sequentially for continuous shooting photography with a motor driven photographic camera, for substantially continuous illumination or for sequential illuminations at intervals, as well as fire the flash tube a single time for one shot photography. The flash device is provided with a main capacitor and an auxiliary capacitor which selectively energize the flash tube or tubes. The auxiliary capacitor is charged by the main capacitor and discharged to energize the flash tube for a small amount of flash light and shorttime restoration of the flash firing circuit. When a pair of flash tubes are employed, they are alternatively actuated for the sequential firing and one of them is actuated for the single time firing. The pair of flash tubes are coupled with each other through a commutation capacitor and switch elements for quick repetition of their firings.

An enlarger having a light emitting device is provided wherein the amount and color balance of light to be emitted are controlled. The operator can set the amount and color balance of light. The enlarger can measure the amount and color balance of light at a plurality of points within a predetermined plane in which the printing paper is to be located. A first mode of operation can be set which presumes a predetermined standard film set in the enlarger and a second mode of operation can be set wherein a film to be printed is placed in the enlarger. The enlarger is capable of averaging a measured signal to determine an average amount and an average color balance of light wherein these measurements can be utilized to determine a proper amount and color balance of light to be received at the predetermined plane during an enlarging operation.

Exposure determining device for an enlarger

An enlarger for use in photography capable of printing a color copy from a color original film includes a light source for generating a plurality of primary colors and a microcomputer for controlling the light source. The microcomputer has various functions which are: for providing a plurality of exposure data corresponding to a plurality of primary colors; for designating at least one of the primary colors; for altering the exposure data corresponding to the designated primary color; for displaying an information relating to the exposure data to be altered; for indicating the direction of change in tone of the color copy caused by altering the exposure data; for selecting the type of the original film; and for controlling the relation between the direction of change in tone of the color copy as indicated and the direction of change in the exposure data as displayed in response to the selected type of original film.

A color enlarger for use in photography capable of printing a color copy from a color original film includes a plurality of source lights for separately generating lights corresponding to a plurality of primary colors; a monitor for separately picking-up the plurality of source lights to monitor the light generated from the light source, and light measuring circuit for separately measuring the plurality of source lights transmitted through the color original film. The color enlarger further includes a microcomputer which has various functions which are: for providing a color data representative of a color to be reproduced on the color copy; for separately calculating the whole light quantities for the plurality of source lights to be generated upon printing the color copy, in response to the monitor, the light measuring circuit, and the provided color data; and for controlling light sources upon printing the color copy in response to the calculating value.

Color enlarger

Light source for exposure

An improved enlarger for producing prints from an image bearing negative includes a film carrier, an enlarging lens, a light source, and a supporting pole for moving the elements to different operative positions. The apparatus is provided for inputting a signal representative of the focal length, and detectors are provided for determining a first and second datum position with the enlarging lens focused at each position. The information representative of these positions can then be used to automatically provide an in-focus position for the enlarging lens at a desired magnification level when the film carrier is subsequently moved.

Automatic focusing device for an enlarger

An exposure control device for a photographic enlarger includes a printing control means for controlling the exposure of a printing section having a light source. When a printing start means is manually operated, the printing control means actuates the printing section to start the exposure of printing and actuates an attained exposure amount outputting means to measure at each segment of time an amount of exposure attained from the start of printing to that time. A suspending signal for temporarily stopping the exposure and the measurement is generated and fed to the printing control means, when a ratio of the attained exposure to a desired exposure reaches an integer multiple of a fixed ratio of exposures. The exposure of the printing section and the measurement of the attained exposure amount are suspended in response to this suspending signal, and an operator can perform a preparatory operation for the shading and/or burning-in printing process during the suspension.

Exposure control device for a photographic enlarger

In an electronic flash device for use in a still camera, a calculation circuit means calculates a ratio of the amounts of light to be emitted by a plurality of flash light tubes on the basis of color temperature information and control circuit means controls the emission of light of the respective flash light tubes in such a manner that the ratio of light amount emitted from the respective flash light tubes corresponds to the ratio calculated by the calculation circuit means.

Growing community of inventors

Kawachinagano, Japan

Yoshio Yuasa