| 摘要 |
PURPOSE:To prevent the generation of ununiformity of picture density, by holding a voltage applied to a heating element constant, or by varying the time width of electric conduction according to the applied voltage to the heating element, and thus making electric supply energy invariably constant. CONSTITUTION:A counter 59 counts the number of data on ''black (recorded)'' in recording data 35 by a horizontal synchronizing signal 6. For example, when a feeding start signal 38 arrives after 28-dot recording data is transferred, a pulse generating circuit 61 generates a pulse 62 with constant width. At the same time, the counted value of the counter 59, i.e. said number of data on ''black'' is set in a counter 60. The counter 60 while regarding the set counted value as its initial value counts the horizontal synchronizing signal 6, and sends a carry output 63 once going up to a specific counted value. A J-KFF64 is set by the output 63 to open an AND gate 66. Therefore, while the 2nd counter 60 goes from the initial value up to the specific counted value, the pulses 62 are masked to inhibit the feeding to a recording head. Namely, the width of a feeding pulse 39 is wider and wider as the initial value of the 2nd counter, i.e. the number of data on ''black'' in the recording data is greater and greater, thereby compensating a voltage drop due to variation of the feeding current to the recording head. |
