Tracking servo device for information reader

Abstract

Abstract PURPOSE:To secure a steady and assured lock-in for the servo, by closing the servo pool when the level of the tracking error signal becomes lower than the fixed level and at the same time the level of the aural carrier signal becomes higher than the fixed level. CONSTITUTION:The servocontrol spots 1 and 2 are converted into the electric signals, and the error signal showing the difference signal is obtained through the differential amplifier 8. This error signal is supplied to the coil 13 which drives the tracking mirror and at the same time compared with the reference voltage V1 to be turned into the pulse signal. This pulse signal is supplied to the AND gate 17 after a differentiation. The reading spot 3 is turned into the reproduced RF signal and then separated into the aural information signal and the video information signal. The RF signal is compared with the reference voltage V2 after receiving a wave detection through the level detecting circuit 27 and then turned into the pulse signal to be used as the gate signal of the gate 17. Then the switch 10 is closed by the timing of the output signal of the gate 17, and the servo loop is closed.

Inventors

• 👤 Minoru Kosake

Bibliographic Details