Automatic control device for correcting filters
First Claim
1. An automatic filter selection apparatus, for selecting from a plurality of light condition correcting filters the proper ones for use in a photography operation, comprisinga. a first discriminator means responsive to the spectral characteristic of an illuminating source of light for providing a first output signal, the condition of which indicates whether or not the illuminating source of light is incandescent lighting,b. a second discriminator means responsive to the amount of flicker is an illuminating source of light for providing a second output signal, the condition of which indicates whether or not the illuminating signal is sunlight,c. first logic means responsive to said first and second output signals for generating a group of logic output signals, the condition of which indicates whether the illuminating light is sunlight, incandescent or fluorescent,d. first selecting means responsive to said group of logic signals for selecting a correcting filter from a first set of said correcting filters in dependence upon the condition of said logic signals,e. second selecting means responsive to said group of logic signals for selecting a correcting filter from a second set of said correcting filters in dependence upon the condition of said logic signals, andf. switching means for selectively applying said group of logic signals to said first and second selecting means.
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Accused Products
Abstract
A control device, adapted to automatically insert a proper correcting filter in a photographing light path dependent upon the color balance of the film used and the type of lighting conditions, is disclosed. Three signals are developed indicating, respectively, that the illuminating light is sunlight, incandescent light, and fluorescent light. The different types of light are detected by a pair of discriminators, one of which is based upon spectral content and the other of which is based on the presence of flicker. Incandescent light is distinguished from the other types of light by its unique spectral characteristic. Sunlight is distinguished from the other types by the absence of an a.c. flicker in such light. The three signals are applied to a mechanism which inserts the filters. A switching means is provided in-between the latter three signals and the filters so that the set of filters connected to be responsive to the three signals depends upon the color balance of the film used.
32 Citations
7 Claims
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1. An automatic filter selection apparatus, for selecting from a plurality of light condition correcting filters the proper ones for use in a photography operation, comprising
a. a first discriminator means responsive to the spectral characteristic of an illuminating source of light for providing a first output signal, the condition of which indicates whether or not the illuminating source of light is incandescent lighting, b. a second discriminator means responsive to the amount of flicker is an illuminating source of light for providing a second output signal, the condition of which indicates whether or not the illuminating signal is sunlight, c. first logic means responsive to said first and second output signals for generating a group of logic output signals, the condition of which indicates whether the illuminating light is sunlight, incandescent or fluorescent, d. first selecting means responsive to said group of logic signals for selecting a correcting filter from a first set of said correcting filters in dependence upon the condition of said logic signals, e. second selecting means responsive to said group of logic signals for selecting a correcting filter from a second set of said correcting filters in dependence upon the condition of said logic signals, and f. switching means for selectively applying said group of logic signals to said first and second selecting means.
Specification