| 摘要 |
PROBLEM TO BE SOLVED: To enhance security of recorded image by heating a same part at different temperatures using a recording medium developing a plurality of colors and recording a unit image, e.g. a unit character, on the recording medium with a plurality of mixed colors while imparting each color with a gradation. SOLUTION: A record control section 15 comprises a conduction time control section 23 generating a conduction time corresponding to a recording energy for black recording and red recording, and a record drive section 22 generating a drive conduction pulse for a thermal head 16 based on that data. The record control section 15 further comprises a weighting table 20 storing a weighting pattern corresponding to the gradation pattern, and a multilevel conversion section 21 for converting a binary pixel into multilevel pixel information with reference to the weighting table 20. A same part is heated at different temperatures using a recording medium developing two different colors and a unit image, e.g. one character, is recorded with two colors while imparting each color with a gradation thus ensuring high security. |
