Patent ID: 6071024
Filing Date: 2000-06-06
Classification: B41J

Abstract:
An ink ribbon positioning system of a color printer for identifying various positions of a color ink ribbon of the color printer and generating corresponding position signals, the color printer comprising a thermal print head and a control circuit which uses the position signals to control the printing of the thermal print head, the ink ribbon being windingly installed inside an ink ribbon box having a plurality of sequentially arranged dye blocks, each of the dye blocks comprising a predetermined number of sequentially arranged transparent color frames for storing different color dyes; the ink ribbon positioning system comprising:a light source installed at one side of the ink ribbon for emitting a light beam of a predetermined color through the ink ribbon;only a single optical sensor for detecting the light beam penetrated through the ink ribbon and generating an output voltage; andan identification device having a plurality of comparators with different predetermined reference voltages respectively, for identifying positions of each of the dye blocks of the ink ribbon and the color frames within each of the dye blocks according to the output voltage generated by the optical sensor and generating corresponding position signals;wherein the light beam of the predetermined color emitted by the light source has different penetration rates for different color frames of each of the dye blocks, and the output voltage generated by the optical sensor varies when each of the color frames within each of the dye blocks passes by the optical sensor, and wherein the identification device generates said corresponding position signals to identify the position of each of the dye blocks and the position of each of the color frames within each dye block according to the comparison of the output voltage of the optical sensor with the reference voltages of the comparators.