| 摘要 |
PURPOSE:To correct print density by automatically detecting the state of input picture quality such as light or deep by a picture quality detection circuit. CONSTITUTION:The picture quality detection circuit 9 is to detect the picture quality state of an input video signal i.e., the state of the input picture quality such as light or deep, and it is comprised of a matrix circuit 10 which converts chrominance signal data of R, G, and B of one picture read out of image memory 3 to luminance signal (Y) data, and a counter circuit 11 which counts the data of the most significant bit in luminance signal data from the matrix circuit 10. A control circuit 7 as a print density correction means compares the detection data A of eight bits of the picture quality detection circuit 9 with plural preset values B1-Bn set in advance, and it is discriminated whether or not the detection data A satisfies either A<B1, B1<=A<B2, B2<=A<B3,...Bn<=A, and the print density is corrected. In such a way, the energizing time of a thermal head is corrected by controlling a print processing circuit 5, thereby, print is performed with the optimum print density. |
