EP0057612A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Motor controlling circuit of reproducing apparatus and method of controlling
Assignee: Sanyo Electric Co Ltd
•
Filing: 1982-02-02
•
Granted: —
•
Expires: 2002-02-02
Abstract
Abstract A reproducing apparatus comprises a motor (9) for driving a digital audio disc (1), in which digital data and a synchronising signal are recorded. The digital data is modulated in accordance with a predetermined digital modulatIng system such as an EFM modulating system, and is then recorded with the synchronising signal, which comprises signals which have a period substantially corresponding to the maximum period of the signals in the digital data, and which occur at a rate greater than that of the signals in the digital data having said maximum period. A signal is reproduced from the disc and the reproduced signal is subjected to FM demodulation and then a control signal is generated based on the FM demodulated signal. The generated control signal as well as a reference signal is applied to a phase comparator (7) of a phase locked loop (10), whereby the phased locked loop (10) controls the rotational speed of the motor (9).
Inventors
- 👤 Toshiaki Hioki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 18:52
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/10527; G11B19/00; G11B19/20; G11B19/28
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
149 words
A motor controlling circuit of a reproducing apparatus, comprising: a recording medium having digital data and a synchronizing signal recorded, said digital data being modulated in a predetermined digital modulation system and recorded on said recording medium, said synchronizing signal being recorded which includes a repetition number of the maximum period signal included in said digital data which repetition number is larger than that in said digital data, a motor for driving said recording medium, reproducing means for reproducing a signal from said recording medium being driven by said motor, FM demodulating means for FM demodulating the signal reproduced from said reproducing means, control signal generating means for generating a control signal based on the signal as FM demodulated by said FM demodulating means, and rotational speed controlling means responsive to the control signal generated by said control signal generating means for controlling the rotational speed of said motor.
Claim 2
Dependent Claim
149 words
A motor controlling circuit of a reproducing apparatus, comprising: a recording medium having digital data and a synchronizing signal recorded, said digital data being modulated in a predetermined digital modulation system and recorded on said recording medium, said synchronizing signal being recorded which includes a repetition number of the maximum period signal included in said digital data which repetition number is larger than that in said digital data, a motor for driving said recording medium, reproducing means for reproducing a signal from said recording medium being driven by said motor, FM demodulating means for FM demodulating the signal reproduced from said reproducing means, control signal generating means for generating a control signal based on the signal as FM demodulated by said FM demodulating means, and rotational speed controlling means responsive to the control signal generated by said control signal generating means for controlling the rotational speed of said motor.
Claim 3
Dependent Claim
64 words
A motor controlling circuit of a reproducing apparatus in accordance with claim 1, wherein said rotational speed controlling means comprises reference signal generating means for generating a reference signal, phase comparing means for comparing the phases of said reference signal and said control signal, and drive controlling means responsive to the output of said phase comparing means for controlling the driving of said motor.
Claim 4
Dependent Claim
45 words
K motor controlling circuit of a reproducing apparatus in accordance with claim 1, wherein said control signal generating means comprises extracting means for extracting a synchronizing signal having a periodicity as said control signal from the signal as FM demodulated from said FM demodulating means.
Claim 5
Dependent Claim
61 words
A motor controlling circuit of a reproducing apparatus in accordance with claim 1, wherein said motor has a predetermined speed, and said control signal generating means comprises speed comparing means for comparing said normal speed with the speed of said motor at that time, and means responsive to said speed comparing means for generating said control signal in a different manner.
Claim 6
Dependent Claim
92 words
A motor controlling circuit of a reproducing apparatus in accordance with claim 4, wherein said control signal generating means comprises clamping means for clamping the signal as FM demodulated by said FM demodulating means at a predetermined level for providing a signal, and means responsive to said speed comparing means for providing as said control signal a signal obtained for the first time after separation by a predetermined interval from a preceding signal from said clamping means when the speed of said motor is equal to or slower than said normal speed.
Claim 7
Dependent Claim
53 words
A motor controlling circuit of a reproducing apparatus in accordance with claim 5, wherein said control signal generating means comprises means responsive to said speed comparing means for providing as said control signal the signal as such from said clamping means when the speed of said motor is faster than said normal speed.
Claim 8
Dependent Claim
60 words
A motor controlling circuit of a reproducing apparatus in accordance with claim 5, wherein said control signal generating means comprises means responsive to said speed comparing means for providing as said control signal the output obtained by adding another signal to the signal obtained from said clamping means when the speed of said motor is faster than said normal speed.
Claim 9
Dependent Claim
68 words
A motor controlling circuit of a reproducing apparatus in accordance with claim 4, wherein said digital data is recorded in said recording midium as a pulse train having a plurality of kinds of signal inversion intervals minimum and maximum of which are predetermined, and said speed comparing means comprises means responsive to said minimum signal inversion interval for comparing said normal speed with the speed of said motor.
Claim 10
Dependent Claim
68 words
A motor controlling circuit of a reproducing apparatus in accordance with claim 4, wherein said digital data is recorded in said recording midium as a pulse train having a plurality of kinds of signal inversion intervals minimum and maximum of which are predetermined, and said speed comparing means comprises means responsive to said maximum signal inversion interval for comparing said normal speed with the speed of said motor.
Claim 11
Dependent Claim
84 words
A motor controlling circuit of a reproducing apparatus in accordance with claim 1, which further comprises means for 1/2 frequency dividing each of the rise and fall of the signal reproduced from said reproducing means, said FM demodulating means FM demodulating the respective outputs from said 1/2 frequency dividing means, and said control signal generating means including means for clamping the respective outputs from said FM demodulating means at a predetermined level, the output from said clamping means being applied as said control signal.
Claim 12
Dependent Claim
81 words
A motor controlling circuit of a reproducing apparatus in accordance with any one of the preceding claims 1 to 10, wherein said motor has a predetermined normal speed, and which further comprises digital demodulating means for digitally demodulating the signal,as reproduced from said reproducing means, and said control signal generating means includes means for generating said control signal based on the signal as digitally demodulated from said digital demodulating means after the speed of said motor has reached said normal speed.
Claim 13
Independent Claim
94 words
A method of controlling a motor, comprising the steps of recording in a recording medium digital data modulated in accordance with a predetermined digital modulating system and recording as said synchronizing signal a maximum period signal included in said digital data with a repetition number larger than that of said digital data, reproducing the signal from said recording medium, FM demodulating said reproduced signal, generating a control signal based on the signal as FM demodulated, and controlling the rotational speed of a motor for driving said recording medium in accordance with said control signal.
Claim 14
Independent Claim
94 words
A method of controlling a motor, comprising the steps of recording in a recording medium digital data modulated in accordance with a predetermined digital modulating system and recording as said synchronizing signal a maximum period signal included in said digital data with a repetition number larger than that of said digital data, reproducing the signal from said recording medium, FM demodulating said reproduced signal, generating a control signal based on the signal as FM demodulated, and controlling the rotational speed of a motor for driving said recording medium in accordance with said control signal.
Claim 15
Dependent Claim
37 words
A method of controlling a motor in accordance with claim 12, wherein said control signal generating step comprises the step of extracting a signal having a periodicity from said signal as FM demodulated as said control signal.
Claim 16
Dependent Claim
57 words
A method of controlling a motor in accordance with claim 12, wherein said motor has a predetermined normal speed, and said control signal generating step comprises the steps of comparing said normal speed with the speed of said, motor at that time, and generating a control signal in different manners depending on the speed of said motor.
Claim 17
Dependent Claim
65 words
A method of controlling a motor in accordance with claim 12, which further comprises the steps of 1/2 frequency dividing the reproduced signal with respect to the rise and fall of said reproduced signal, FM demodulating said 1/2 frequency divided signal, clamping said FM demodulated signal at predetermined levels, and providing as said control signal the signal obtained by clamping the signal as FM demodulated.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.