Electronic flash device
AssigneeMinolta Camera Kabushiki Kaisha
InventorsIchiro Yoshiyama, Yoshio Yuasa, Nobuyuki Taniguchi, Norio Ishikawa
Life of this patent
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Abstract
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.
Claims24
An electronic flash device for use in a still camera, said device comprising:
- means for producing color temperature information;
- at least two flash light emitting means, each of which can emit flash light having different spectral characteristics;
- calculation circuit means for calculating a ratio of the amounts of light to be emitted by the respective flash light emitting means on the basis of the information fed from the means for producing the color temperature information;
- and
- control circuit means for controlling the emission of light of the respective flash light emitting means in such a manner that the ratio of the light amount emitted from the respective flash light emitting means corresponds to the ratio calculated by the calculation circuit means.
An electronic flash device for use with a still camera, said device comprising:
- means for producing color temperature information;
- at least two flash light emitting means each of which can emit light having different spectral characteristics;
- first flash control means provided for controlling the starting and stopping of the light emission of one of the flash light emitting means;
- second light measuring means for measuring the amount of light emitted from said one of the flash light emitting means;
- light amount calculating means for calculating the amount of light to be emitted by the remaining flash light emitting means on the basis of a value defined by the amount of light measured by the second light measuring means and the color temperature information;
- and
- second flash control means for controlling the starting and stopping of the remaining flash light emitting means on the basis of the result of the calculation in the light amount calculation means.
An electronic illuminating device for cameras comprising:
- means for measuring the amount of red, blue and green color in an ambient light object scene and producing corresponding color signals;
- means for producing color temperature signals from the color signals to calculate the desired quantity of each light to be added to the ambient light to produce a uniform color tone of the desired scene to be recorded including means for taking into consideration the spectral characteristics of the recording medium;
- means for selectively emitting light of a red, blue and green color;
- and
- means for controlling the total quantity of one color light produced by the emitting means as a function of the total quantity of another color predetermined from the means for producing color temperature signals and a ratio of the actually measured light of those respective colors.
An auxiliary illumination lighting device to assist in recording color images of an object scene comprising:
- means for measuring the amount of ambient light of different spectral values and producing corresponding signals;
- means for providing color temperature information from the measured signals to enable a uniform color tone of the desired scene to be recorded;
- at least two separate sources of light for emitting light of different spectral characteristics, and
- automatic means for controlling the total quantity of light of one spectral characteristic as a function of a total quantity of the other spectral characteristic light predetermined from the means for providing color temperature and a ratio of the actually measured light of each spectral characteristic.
Dependencies are inferred from the claim text.