Spindle motor controlling circuit of an optical disk system
First Claim
1. A circuit for controlling a spindle motor of an optical disk system, comprising:
- spindle motor rotation sensing means for generating a phase frequency in accordance with an amount of rotation of said spindle motor;
means for setting a variable desired spindle motor speed;
means for setting a variable desired phase value;
speed error signal generating means for generating speed error data indicative of a difference between a period of said phase frequency and data representing said variable desired spindle motor speed;
speed driving voltage generating means for generating a speed driving voltage corresponding to said generated speed error data and for driving said spindle motor according to said generated speed driving voltage; and
means for automatically controlling a phase difference between said spindle motor and said variable desired phase value when said speed error data is within a predetermined range and while said speed driving voltage generating means drives said spindle motor according to said speed driving voltage, and disabling control of said phase difference when said speed error data exceeds said predetermined range.
1 Assignment
0 Petitions
Accused Products
Abstract
A spindle motor controlling circuit for controlling the rotation of an optical disk system using a constant linear velocity servo. The circuit includes a spindle motor rotation sensing circuit for generating a phase frequency in response to the rotation of the spindle motor. A speed control part of the controlling circuit includes a speed error signal generating circuit that generates speed error data indicative of a difference between the period of the phase frequency and data representing a desired spindle motor speed. A phase control part of the control circuit includes a phase coefficient pulse generating circuit, a reference phase signal generating circuit and a phase error signal generating circuit. Finally, the controlling circuit includes a driving voltage generating circuit for generating a speed driving voltage corresponding to the speed error data and a phase driving voltage corresponding to the phase error signal. The driving voltages are used for driving the spindle motor.
-
Citations
12 Claims
-
1. A circuit for controlling a spindle motor of an optical disk system, comprising:
-
spindle motor rotation sensing means for generating a phase frequency in accordance with an amount of rotation of said spindle motor; means for setting a variable desired spindle motor speed; means for setting a variable desired phase value; speed error signal generating means for generating speed error data indicative of a difference between a period of said phase frequency and data representing said variable desired spindle motor speed; speed driving voltage generating means for generating a speed driving voltage corresponding to said generated speed error data and for driving said spindle motor according to said generated speed driving voltage; and means for automatically controlling a phase difference between said spindle motor and said variable desired phase value when said speed error data is within a predetermined range and while said speed driving voltage generating means drives said spindle motor according to said speed driving voltage, and disabling control of said phase difference when said speed error data exceeds said predetermined range. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A circuit for controlling a spindle motor of an optical disk system, comprising:
-
spindle motor rotation sensing means for generating a phase frequency in accordance with an amount of rotation of said spindle motor; speed error signal generating means for generating speed error data indicative of a difference between a period of said phase frequency and data representing a desired spindle motor speed; phase coefficient pulse generating means for generating a current-position phase pulse from said phase frequency just before said spindle motor performs a shift from a current position and for generating double edge detecting pulses by detecting rising and falling edges of said phase frequency occurring subsequent to said current-position phase pulse; desired phase detecting means for generating a desired phase detecting signal when, in response to said current-position phase pulse, said double edge detecting pulses are counted up to a desired phase data value, said desired phase data value indicating a number of double edge detecting pulses to be counted up to arrival at a desired position after the shift is completed; reference phase signal generating means for setting a reference phase data value corresponding to N times said data representing the desired spindle motor speed to one rotation period of a desired track, for counting a first clock in response to said current-position phase pulse, and for generating a reference phase detecting signal when the counted value reaches the set reference phase data value; phase error signal generating means for detecting a phase difference between a current phase and a desired phase in response to said reference phase detecting signal, and for generating a phase error signal in accordance with said phase difference; and driving means for generating a speed driving voltage and a phase driving voltage, corresponding to said speed error data and said phase error signal, respectively, in order to drive said spindle motor. - View Dependent Claims (7, 8, 9, 10)
-
-
11. A method of controlling a spindle motor of an optical disk system using a constant linear velocity servo, comprising the steps of:
-
generating a phase frequency in accordance with an amount of rotation of said spindle motor, by sensing rotation of said spindle motor; setting a variable desired spindle motor speed; setting a variable desired phase value; generating speed error data indicative of a difference between a period of said phase frequency and data representing said variable desired spindle motor speed; generating a speed driving voltage corresponding to said generated speed error data and driving said spindle motor according to said generated speed driving voltage; and automatically controlling a phase difference between said spindle motor and a desired phase value when said speed error data is within a predetermined range and while said speed driving voltage generating means drives said spindle motor according to said speed driving voltage, and disabling control of said phase difference when said speed error data exceeds said predetermined range.
-
-
12. A circuit for controlling a spindle motor of an optical disk system using a constant linear velocity, comprising:
-
generating a phase frequency in accordance with an amount of rotation of said spindle motor, by sensing rotation of said spindle motor; generating a current position phase pulse from said phase frequency just before said spindle motor performs a shift from a current position and generating double edge detecting pulses by detecting rising and falling edges of said phase frequency occurring subsequent to said current position phase pulse; generating a desired phase detecting signal when, in response to said current position phase pulse, said double edge detecting pulses are counted up to a desired phase data value, said desired phase data value indicating a number of double edge detecting pulses to be counted up to arrival at a desired position after the shift is completed; setting a reference phase data value corresponding to N times said data representing the desired spindle motor speed to one rotation period of a desired track, counting a first clock in response to said current-position phase pulse, and generating a reference phase detecting signal when the counted value reaches the set reference phase data value; detecting a phase difference between a current phase and a desired phase in response to said reference phase detecting signal, and generating a phase error signal in accordance with said phase difference; and generating a phase driving voltage, corresponding to said phase error signal, in order to drive said spindle motor.
-
Specification