PURPOSE: To realize the reliability as well as a simple and compact structure for a tilt signal generating circuit, by controlling the charge/discharge of a constant current to a capacitor only through a logical circuit.

CONSTITUTION: When the sample holding pulse S/H is set at a low level, a switch SW1 is turned on via an AND gate 3. At the same time, a switch SW2 is also turned on with a low level output of an NAND gate 8 via an inverter 7, etc. to which the RS type FF reference signals produced from the NAND gates 5 and 6 which work in response to a high level output of a level comparator 4 is applied. Then the switch SW2 is turned off by the comparator 4 and the RS type FF when a capacitor C discharges a constant current to reach a prescribed level of voltage. Thus the capacitor C receives the charge of a constant current to produce a tilt signal, and the level is clamped via a transistor Q1 when the capacitor C reaches a prescribed level of voltage. In such way, the charge/discharge of the constant current is controlled only by a logical circuit with no use of a monostable multivibrator which is unstable to the temperature, etc. Thus the reliability and a simple and compact structure are attained for a tilt signal generating circuit.