Color sensing method and device therefor

A color sensing device, comprising:

• an insulating substrate;
• two first electrodes being formed on said substrate separate from each other;
• an amorphous silicon layer containing an impurity so as to act-as an n-type or p-type semiconductor applied on said electrodes;
• two second electrodes made of transparent conducting material being on said n-type or p-type amorphous silicon layer so as to oppose said first electrodes interposing said amorphous silicon layer, respectively;
• an electric power source for applying a positive voltage and a negative voltage to each pair of a first electrode and a second electrode at the same time, and
• a divider means for calculating a ratio of the two photocurrents obtained, each of which flows between each pair of a first electrode and a second electrode.

A color sensing device for identifying the color of incident light comprising:

• an insulating substrate;
• two first electrodes formed on the substrate and spaced from each other;
• an amorphous silicon layer containing an impurity so as to act as an n-type or p-type semiconductor applied on said electrodes;
• two second electrodes made of a transparent conducting material and positioned on the n-type or p-type amorphous silicon layer so as to be operatively positioned opposite the first electrodes, respectively;
• an electric power source for applying a positive voltage to one set of electrodes and a negative voltage to the other set of electrodes;
• means for measuring the photoelectric current from each set of electrodes when subject to incident light, and
• means for determining the color of the incident light from the measured photoelectric currents.