| 摘要 |
PROBLEM TO BE SOLVED: To reproduce gradation number, move than the number of toner particles able to be transferred to one pixel area on a printed output image in the toner transfer type printer. SOLUTION: A RAM 3 is provided to convert gradation data of each pixel of image data 400 into pulse width data of each pixel of an output image. The RAM3 has 9 picture element areas 31-39 corresponding to 9 picture elements a-i in an output image to form, e.g. a 3×3 matrix. Each of the 9 pixel areas 31-39 stores 256 pulse width data corresponding to a number 256 that is a maximum number for kinds of gradation data. The pulse width data in the 9 pixel areas 31-39 are mutually different very slightly among the 9 pixel pixels areas. Gradation data 23 of each pixel of the image data 400 and an address word 2 constituting of coordinates 21, 22 of each pixel in a ×3 pixel matrix are given to the RAM 3. Then the pulse width data corresponding to the gradation data 23 are read from the 9 pixel areas and a laser drive pulse with a pulse width corresponding to the data is generated. |
