| 摘要 |
A cleaning wheel positioning mechanism for precisely controlling the contact pressure of a cleaning wheel against a recording drum in a magnetic recording system is presented. In accordance with the invention, the cleaning wheel positioning controller uses knowledge of the drum drive motor voltage (or current) to detect the contact pressure of the cleaning wheel against the drum. During a cleaning operation, which preferably occurs automatically during a periodic cycle, the cleaning wheel positioning controller first detects a reference drum motor voltage/current based on the drum drive motor voltage/current when the cleaning wheel is in its fully retracted position. Cleaning wheel positioning controller then monitors the drum drive motor voltage/current, and compares it to the reference drive motor voltage/current. When a predetermined amount of increase in drum drive motor voltage/current over the reference voltage/current value occurs, which indicates that the cleaning wheel is positioned against the drum, the cleaning wheel positioning controller effectuates the halting of movement of the cleaning wheel rack, preferably by turning off the cleaning wheel drive motor.
|
