Patent EP0332099A2 successfully refreshed from Google Patents.
EP0332099A2
Expired / Lapsed
EP
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Control circuit for spindle motor
Assignee: NEC Corp
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Filing: 1989-03-06
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Granted: —
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Expires: 2009-03-06
Abstract
Abstract A control circuit for controlling according to external standard pulses a spindle motor used to rotate a recording disc medium pre-recorded thereon with clock data indicative of angular position thereof. A detecter operates during the rotation of recording disc medium for detecting the clock data and producing successively clock pulses in response to detection of the clock data. A comparator compares phase of the clock pulses with that of the external standard pulses inputted from a standard pulse source outside the control circuit to produce a phase error signal indicative of phase difference between the clock pulses and the standard pulses. A controller controls rotation speed of the spindle motor according to the phase error signal to thereby synchronize the clock pulses to the standard pulses.
Inventors
- 👤 Hideaki C/O Nec Corporation Uchikura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 00:45
CPC Classifications
G; G11; G11B; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G11B27/32; G11B19/00; G11B19/20; G11B19/28
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
124 words
A control circuit for controlling a spindle motor used to rotate a recording disc medium pre-recorded thereon with clock data indicative of angular position thereof, characterized by: detecting means operative during the rotation of recording disc medium for detecting the clock data and producing successively clock pulses in response to detection of the clock data; comparing means for comparing phases of the clock pulses with that of external standard pulses inputted from a standard pulse source outside the control circuit to produce phase error signals indicative of phase differences between the clock pulses and the standard pulses; and controlling means for controlling rotation speed of the spindle motor according to the phase error signal to thereby synchronize the clock pulses to the standard pulses.
Claim 2
Dependent Claim
124 words
A control circuit for controlling a spindle motor used to rotate a recording disc medium pre-recorded thereon with clock data indicative of angular position thereof, characterized by: detecting means operative during the rotation of recording disc medium for detecting the clock data and producing successively clock pulses in response to detection of the clock data; comparing means for comparing phases of the clock pulses with that of external standard pulses inputted from a standard pulse source outside the control circuit to produce phase error signals indicative of phase differences between the clock pulses and the standard pulses; and controlling means for controlling rotation speed of the spindle motor according to the phase error signal to thereby synchronize the clock pulses to the standard pulses.
Claim 3
Dependent Claim
29 words
A control circuit as claimed in claim 1, characterized in that the said clock data is an index clock pulse occuring once each ratation of the recording disc medium.
Claim 4
Dependent Claim
61 words
A control circuit as claimed in claim 1 or 2, characterized in that the detecting means includes a pattern decoder for decoding the clock data to produce index clock pulses occurring once each rotation of the recording disc medium and being used for coarse synchronization, and to produce bit clock pulses occurring on bit-by-bit basis and being used for fine synchronization.
Claim 5
Dependent Claim
104 words
A control circuit as claimed in claim 3, characterized in that the comparing means includes a first phase comparator for comparing the phase of index clock pulses with that of first standard pulses set to occur once each rotation of the recording disc medium to thereby produce a coarse phase error signal effective to coarsely control the rotation of spindle motor, and a second phase comparator for comparing the phase of bit clock pulses with that of second standard pulses set to occur periodically on the bit-by-bit basis to produce a fine phase error signal effective to finely control the rotation of spindle motor.
Claim 6
Dependent Claim
46 words
A control circuit as claimed in claim 4, characterized in that the first phase comparator includes means operative when the phase of index clock pulses matches with that of the first standard pulses to produce a phase-matching confirming signal effectire to activate the second phase comparator.
Claim 7
Dependent Claim
34 words
A control circuit as claimed in claim 4 or 5, characterized in that the comparing means includes a low-pass filter for leveling the fine phase error signal for direct use in the controlling means.
References Cited (Backward Citations)
No citation records indexed.
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