Color sensor system using a secondary light receiver

Claim 1

A photoelectric color sensor comprising: at least two light sources disposed in a fixed array directed toward an optical transmission device having a primary path for transmitting light from said light sources to an object whose color is to be measured and a secondary path, each of said light sources operable to generate emitted light having a limited characteristic range of chromaticity differing from the characterization range of chromaticity of each other light source; a primary photosensitive receiver positioned to receive said emitted light reflected from an object whose color is to be measured; a secondary photosensitive receiver positioned to receive a portion of said emitted light transmitted from said light sources through said secondary path; said secondary photosensitive receiver generating an output signal representing the level of said emitted light; a control circuit connected between said secondary photosensitive receiver and said light sources for controlling the light energy emitted by said light sources, said control conduit having a level comparator electrically connected to said secondary photosensitive receiver for comparing said output signal to a reference level and controlling a current driver for powering said light sources to produce a level of emitted light according to said reference level logic means in circuit with said light sources and said primary photosensitive receiver operative to sequentially energize said light sources and to receive resultant sample signals from said primary photosensitive receiver in response to each said light source energization, said logic means being further operative to generate a resultant signal as a function of said sample signals, to compare said resultant signal with a predetermined reference standard and generate a condition output signal when the difference between said resultant signal and reference standard exceeds a tolerance limit, wherein said reference standard has been established during an earlier test mode operation of said logic means in which a standard color mode operation of said logic means in which sensing region and sequentially illuminated by said light sources, said reference standard and said resultant signal comprising a respective single signal for each said characteristic range of chromaticity.

Claim 19

A method of measuring the color of an object comprising: providing at least two light sources disposed in a fixed array directed toward an optical transmission device having a primary path for transmitting light from said light sources to an object whose color is to be measured and a secondary path, each of said light sources operable to emit light having a limited characteristic range of chromaticity; providing a primary photosensitive receiver positioned to receive reflected light from said object whose color is to be measured for generating a primary signal indicative of a level of said reflected light; providing a secondary photosensitive receiver positioned to receive light from said secondary path for generating a secondary signal indicative of a level of light transmitted along said secondary path; providing a microprocessor for calculation of the color of said object dependent on said primary signal and said secondary signal; energizing at least one of said light sources having a selected chromaticity; dividing said primary signal by said secondary signal to obtain a resultant; and transmitting said resultant to said microprocessor for calculation of a level of color.

Claim 20

A method of measuring the color of an object comprising: providing at least two light sources disposed in a fixed array directed toward an optical transmission device having a primary path for transmitting light from said light sources to an object whose color is to be measured and a secondary path, each of said light sources operable to emit light having a limited characteristic range of chromaticity; providing a primary photosensitive receiver positioned to receive reflected light from said object whose color is to be measured for generating a primary signal indicative of a level of said reflected light; providing a secondary photosensitive receiver positioned to receive light from said secondary path for generating a secondary signal indicative of a level of light transmitted along said secondary path; providing a microprocessor for calculation of the color of said object dependent on said primary signal and said secondary signal; energizing at least one of said light sources having a selected chromaticity; dividing said primary signal by said secondary signal to obtain a resultant; and transmitting said resultant to said microprocessor for calculation of a level of color.

Claim 21

A method of measuring the color of an object comprising: providing at least two light sources disposed in a fixed array directed toward an optical transmission device having a primary path for transmitting light from said light sources to an object whose color is to be measured and a secondary path, each of said light sources operable to emit light having a limited characteristic range of chromaticity; providing a primary photosensitive receiver positioned to receive reflected light from said object whose color is to be measured for generating a primary signal indicative of a level of said reflected light; providing a secondary photosensitive receiver positioned to receive light from said secondary path for generating a secondary signal indicative of a level of light transmitted along said secondary path; providing a microprocessor for calculation of the color of said object dependent on said primary signal and said secondary signal; providing a current driver to power said light sources; providing a level comparator connected to said secondary photosensitive receiver and to said current driver; energizing at least one of said light sources having a selected chromaticity; comparing said secondary signal to said reference power signal and transmitting a resultant to said current driver; adjusting the output of said current driver according to said resultant to control the level of light transmission from said light sources; and transmitting said primary signal to said microprocessor for calculation of the color of said object.

Claim 22

A method of measuring the color of an object comprising: providing at least two light sources disposed in a fixed array directed toward an optical transmission device having a primary path for transmitting light from said light sources to an object whose color is to be measured and a secondary path, each of said light sources operable to emit light having a limited characteristic range of chromaticity; providing a primary photosensitive receiver positioned to receive reflected light from said object whose color is to be measured for generating a primary signal indicative of a level of said reflected light; providing a secondary photosensitive receiver positioned to receive light from said secondary path for generating a secondary signal indicative of a level of light transmitted along said secondary path; providing a microprocessor for calculation of the color of said object dependent on said primary signal and said secondary signal; providing a current driver to power said light sources; providing a level comparator connected to said secondary photosensitive receiver and to said current driver; energizing at least one of said light sources having a selected chromaticity; comparing said secondary signal to said reference power signal and transmitting a resultant to said current driver; adjusting the output of said current driver according to said resultant to control the level of light transmission from said light sources; and transmitting said primary signal to said microprocessor for calculation of the color of said object.