| 摘要 |
PURPOSE:To enable multi-gradation images to be printed, by a method wherein a multi-gradation test pattern is recorded prior to normal recording on a paper, the ink density of the test pattern is detected by a detector, and variations in recorded density characteristics with variations in printing conditions are corrected. CONSTITUTION:Prior to normal recording, a test printing command 9 causes a multi-gradation pattern generating circuit to record a multi-gradation test pattern 16 on the paper 5, the density of the recorded test pattern is detected by the detector 7, and the detection signal is processed by a memory, a discriminating circuit 12, a dividing circuit 13 and a recorded density characteristic correcting circuit 14. Therefore, the record density characteristics under total recording conditions such as an ink paper 1, the paper 5, a thermal head 3 and the ambient temperature. Accordingly, when a printing command 15 is inputted to a head-driving circuit 10 after the above operations, the multi- gradation printing data contained in the printing command 15 are converted into pulses corresponding to voltage-impressing time by the circuit 14 in accordance with the recorded density characteristics, and the pulses are outputted, thereby performing normal recording on the paper 5. |
