Servo circuit positioning actuator
First Claim
Patent Images
1. A servo circuit comprising:
- positioning actuator means for moving an object in response to a servo signal;
detector means, having a plurality of outputs, for varying a first set of said outputs in accordance with the position of the object;
signal processing means for receiving said outputs of said detector means, for digitally processing said first set of outputs such that a sum of said first set of outputs normalizes a difference of said first set of outputs and for providing the servo signal varying in accordance with said processing of said first set of outputs, said signal processing means includingA/D conversion means for converting an analog input to digital form in accordance with said sum of said first set of outputs and for providing, as a digital output, the digital form of said analog input, a digital form of said difference of said first set of outputs corresponding to said servo signal, andmeans for providing said difference of said first set of outputs to said analog input; and
additional positioning actuator means for moving an additional object in response to an additional servo signal, and whereinsaid detector means comprises means for varying a second set of said plurality of outputs in accordance with the position of said additional object, and whereinsaid means for providing comprises time division switching means for selectively providing said difference of said first set of outputs and a difference of said second set of outputs to said analog input of said A/D conversion means, such that a digital form of said differences of said second set of outputs corresponds to said additional servo signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A servo system for controlling the position of an object in accordance with a servo signal, employing an A/D converter to normalize an error in the position of the object and to enable digital correction of any offset in the system and digital compensation for track jumping and drop outs.
-
Citations
5 Claims
-
1. A servo circuit comprising:
-
positioning actuator means for moving an object in response to a servo signal; detector means, having a plurality of outputs, for varying a first set of said outputs in accordance with the position of the object; signal processing means for receiving said outputs of said detector means, for digitally processing said first set of outputs such that a sum of said first set of outputs normalizes a difference of said first set of outputs and for providing the servo signal varying in accordance with said processing of said first set of outputs, said signal processing means including A/D conversion means for converting an analog input to digital form in accordance with said sum of said first set of outputs and for providing, as a digital output, the digital form of said analog input, a digital form of said difference of said first set of outputs corresponding to said servo signal, and means for providing said difference of said first set of outputs to said analog input; and additional positioning actuator means for moving an additional object in response to an additional servo signal, and wherein said detector means comprises means for varying a second set of said plurality of outputs in accordance with the position of said additional object, and wherein said means for providing comprises time division switching means for selectively providing said difference of said first set of outputs and a difference of said second set of outputs to said analog input of said A/D conversion means, such that a digital form of said differences of said second set of outputs corresponds to said additional servo signal. - View Dependent Claims (2, 3, 4, 5)
-
Specification