| 摘要 |
<p>PURPOSE:To ensure the uniform luminance with a simple circuit, by forming a luminance pulse similar to a trapezoidal wave by making use of the charging/ discharging function of a capacitor due to a square wave. CONSTITUTION:A pulse generating circuit 2 transmits a square wave pulse of a certain level on the basis of the trigger pulse of a transmission trigger circuit 1. This pulse width can be varied in response to the range of detection. For the transmission period of the pulse, a current flows to a capacitor 7 via resistances 3 and 4 and a diode 6 to perform charging. While the charged electric charge of the capacitor 7 is discharged via a resistance 5 in a period of pause. This charged voltage is cut in terms of DC at a point A by a capacitor 8 and then added to the split voltage which is previously set by the operation of a changeover switch 10 and in response to each detecting range decided by a split resistance 9 of voltage E0 to be split. Thus a luminance signal is supplied to a CRT 11.</p> |
