US4653040A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Disk size detecting circuit
Assignee: Pioneer Corp
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Filing: 1985-03-18
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Granted: 1987-03-24
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Expires: 2005-03-18
Abstract
Abstract In a disk size detecting circuit, the size of a disk is determined according to the speed of a motor adapted to rotate the disk and the angle through which motor has rotated after the start thereof. A counter, which is reset with the signal which starts the operation of the motor, counts pulses indicative of the amount of rotation of the motor. A rotational speed detector circuit, which may take the form of a frequency-to-voltage converter followed by a voltage comparator or a frequency counter followed by a digital comparator, produces a signal indicating the rotational speed of the motor. The output of the counter and the output of the rotational speed detector are applied to a circuit which discriminates the size of the disk according to the two signals.
Inventors
- 👤 Hitoshi Senso
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:43
CPC Classifications
G; G11; G11B; G11B19/00; G11B19/02; G11B19/12; G11B19/20; G11B19/28; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/908; Y10S388/912
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
96 words
A disk size detecting circuit comprising: an electric motor for rotating a disk; rotational speed detecting means for producing a speed signal having a first state when a rotational speed of said motor exceeds a predetermined rotational speed and a second state otherwise; rotational angle detecting means for producing an angle signal indicating an angle through which said motor has rotated after the start thereof; and means for comparing said angle signal with a reference value at a transition of said speed signal between said first and second states, thereby discriminating the size of said disk.
Claim 2
Dependent Claim
96 words
A disk size detecting circuit comprising: an electric motor for rotating a disk; rotational speed detecting means for producing a speed signal having a first state when a rotational speed of said motor exceeds a predetermined rotational speed and a second state otherwise; rotational angle detecting means for producing an angle signal indicating an angle through which said motor has rotated after the start thereof; and means for comparing said angle signal with a reference value at a transition of said speed signal between said first and second states, thereby discriminating the size of said disk.
Claim 3
Dependent Claim
45 words
The disk size detecting circuit of claim 1, wherein said rotational angle detecting means comprises a counter having a count input receiving a pulse signal, each pulse indicating a predetermined angular rotation of said motor and further having an output applied to said comparing means.
Claim 4
Dependent Claim
90 words
The disk size detecting circuit of claim 2, wherein said rotational speed detecting means comprises: a rotational speed detecting pulse generator coupled to said motor, said input of said counter being coupled to an output of said rotational speed detecting pulse generator; a frequency-to-voltage converter having an input coupled to said output of said rotational speed detecting pulse generator; and a voltage comparator having a first input terminal coupled to an output terminal of said frequency-to-voltage converter and a second input terminal coupled to a source of a reference voltage.
Claim 5
Dependent Claim
72 words
The disk size detecting circuit of claim 2, wherein said rotational speed detecting means comprises: a rotational speed detecting pulse generator coupled to said motor; a second counter having a count input coupled to an output of said rotational speed detecting pulse generator; and a digital comparator having a first input port coupled to a count output port of said second counter and a second input port receiving a comparison digital value.
Claim 6
Dependent Claim
27 words
The disk size detecting circuit of claim 2, wherein a start signal for starting operation of said motor is applied to a reset input of said counter.
Claim 7
Dependent Claim
33 words
The disk size detecting circuit of claim 2, further comprising delay means coupled between a source of a start signal for starting operation of said motor and a reset input of said counter.
Claim 8
Dependent Claim
76 words
The disk size detecting circuit of claim 3, wherein said rotational angle detecting means comprises: a second frequency-to-voltage converter having an input coupled to an output of said rotational speed detecting pulse generator; and a second voltage comparator having a first input terminal coupled to an output of said second frequency-to-voltage converter, a second input terminal coupled to a source of a second reference voltage, and an output coupled to a reset input of said counter.
Claim 9
Dependent Claim
20 words
The disk size detecting circuit of claim 7, wherein said second reference voltage is lower than said first-mentioned reference voltage.
References Cited (Backward Citations)
JPS5334502A
Cited
US4302833A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-23 | 1990-09-22 | 1991-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-23 | 1994-09-22 | 1995-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-23 | 1998-09-22 | 1999-03-24 | $7700.00 | Window Closed / Lapsed |