Abstract: An information processing apparatus having the function of reproducing digital information recorded on a recording medium has binarizing circuit for transforming a reproduction signal read from the recording medium into a binary signal, circuit for making from the binary signal a bit synchronous signal for use when the binary signal is demodulated, circuit for detecting the inverted portion of the binary signal by a periodical window of a predetermined period and producing a synchronous binary signal synchronized with the bit synchronous signal in accordance with the result of the detection, demodulating circuit for demodulating the digital information on the recording medium on the basis of the synchronous binary signal, and circuit for varying the period of the window in conformity with the situation.

Abstract: To adjust the density of alphanumeric to be thermally printed by a thermal printer, a time duration for applying the row or column drive current to the selected dot elements in a thermal head is varied so as to vary a time duration for which the selected dot elements are energized, to thereby change the quantity of heat dissipated therefrom depending upon the environmental temperature, the thermal characteristics and aging of thermally sensitive paper and so forth. The drive current flowing duration may be varied by varying a cycle of the drive current signals to be sequentially applied to the row or column drive lines of a dot element matrix circuit through a character generator. In one embodiment of the present invention, the cycle of the drive current signals may be varied by the frequency division or count down of the clock pulses with a variable pulse repetitive rate used in an electronic computer.