Thermal recorder

Abstract

Abstract PURPOSE:To compensate the nonlinearity of color development density characteristic to perform multigradation control in a wide temperature range by reading out time information corresponding to a gradation from the second storage part when heating is controlled a number of times corresponding to the gradation and determining the time of each heating driving on a basis of this information. CONSTITUTION:An A/D converting circuit 4 outputs a demodulated picture element signal having 16-stage gradation information, and a selector 6 leads into a storage part 7 or 8 selectively on a basis of a switching signal MSEL. 2048 picture elements corresponding to one scanning line are stored in storage parts 7 and 8. The read address of a read address counter 14 consists of 11 bits of the total of upper and lower outputs, and picture elements are read out from storage parts 7 and 8 16 times in 256-picture element unit. The middle output is inputted as a 4-bit gradation signal to an input B of a comparator 15. This signal is changed at every read time. The comparator 15 compares inputs A and B with each other to picture element signals ''1'' or ''0'' successively. Consequently, picture element signals of storage parts 7 and 8 heat a head 2 a number of times corresponding to the gradation. A processor 16 makes the signal width of an enable signal ENB different each time when 8 signals ENB are given to the head 15 times. Time information indicating the signal width is stored in a ROM17.

Inventors

• 👤 Yoshihiro Hobo
• 👤 芳博 保母

Bibliographic Details