US5810477A
Expired / Lapsed
US
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System for identifying surface conditions of a moving medium
Assignee: International Business Machines Corp
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Filing: 1996-05-06
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Granted: 1998-09-22
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Expires: 2016-05-06
Abstract
Abstract A method and apparatus for mapping the character and location of medium conditions for a planar surface. Energy is supplied to a head in close proximity to the planar surface to thereby raise the temperature of the object. The head is moved with respect to the planar surface while keeping the distance from the planar surface substantially constant. An increase, decrease or a rapid variation containing positive and negative temperature excursions is distinguished by electronic means. These variations are used to categorize disturbances or contact with the medium, and the location and type of condition is recorded in hard copy or by computer acquisition for later consideration in the file manufacture process. Additionally, magnetic and thermal information may be combined to provide an even more complete description of the nature of the condition, since the magnetic and thermal signals are descriptive of different physical phenomenon.
Inventors
- 👤 David William Abraham
- 👤 Timothy Joseph Chainer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:15
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/012; G11B11/00; G11B13/00; G11B17/00; G11B17/32; G11B20/00; G11B20/10; G11B20/10009; G11B20/24; G11B33/00; G11B33/10; G11B5/48; G11B5/58; G11B5/596; G11B5/59683; G11B5/60; G11B5/6005; G11B5/6011; G11B5/6076; G11B11/03; G11B11/06; G11B19/00; G11B19/02; G11B19/04; G11B2005/0002; G11B2005/0005; G11B2005/0021; G11B5/02; G11B5/59633; G11B5/74; G11B5/82
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
259 words
A system for identifying surface conditions of a medium moving relative to a head, comprising: an input node for receiving an input signal, the input signal being primarily representative of a thermal environment over the medium monitored by said head; a first processing path coupled to the input node for determining whether the input signal received therefrom meets a first criteria, the first criteria corresponding to a first type of surface disturbance on the medium, wherein the first processing path provides an active first signal indicative of the input signal rising above/falling below a first reference level comprising said first criteria, the first processing path including: a first comparator coupled to the input node for receiving the input signal therefrom, the first comparator for comprising the input signal to the first reference level, and a first pulse generator, triggered by the first comparator, for providing the active first signal; and a second processing path coupled to the input node for determining whether the input signal received therefrom meets a second criteria, the second criteria corresponding to a second type of surface disturbance on the medium, wherein the second processing path provides an active second signal indicative of the input signal falling below/rising above a second reference level comprising said second criteria, the second processing path including: a second comparator coupled to the input node for receiving the input signal therefrom, the second comparator for comparing the input signal to the second reference level, and a second pulse generator, triggered by the second comparator, for providing the active second signal.
Claim 2
Independent Claim
259 words
A system for identifying surface conditions of a medium moving relative to a head, comprising: an input node for receiving an input signal, the input signal being primarily representative of a thermal environment over the medium monitored by said head; a first processing path coupled to the input node for determining whether the input signal received therefrom meets a first criteria, the first criteria corresponding to a first type of surface disturbance on the medium, wherein the first processing path provides an active first signal indicative of the input signal rising above/falling below a first reference level comprising said first criteria, the first processing path including: a first comparator coupled to the input node for receiving the input signal therefrom, the first comparator for comprising the input signal to the first reference level, and a first pulse generator, triggered by the first comparator, for providing the active first signal; and a second processing path coupled to the input node for determining whether the input signal received therefrom meets a second criteria, the second criteria corresponding to a second type of surface disturbance on the medium, wherein the second processing path provides an active second signal indicative of the input signal falling below/rising above a second reference level comprising said second criteria, the second processing path including: a second comparator coupled to the input node for receiving the input signal therefrom, the second comparator for comparing the input signal to the second reference level, and a second pulse generator, triggered by the second comparator, for providing the active second signal.
Claim 3
Dependent Claim
31 words
The system of claim 1, further comprising: a sensor for monitoring said thermal environment; and a circuit, in cooperation with said sensor, to provide the input signal to the input node.
Claim 4
Dependent Claim
16 words
The system of claim 1, wherein a magnetoresistive element is used to monitor the thermal environment.
Claim 5
Dependent Claim
19 words
The system of claim 3, wherein the magnetoresistive element is also used to magnetically read data from said medium.
Claim 6
Dependent Claim
47 words
The system of claim 1, further comprising: another input node for receiving another input signal, the another input signal being representative of a magnetic environment on the moving medium; and a magnetic environment processing path for processing the another magnetic input signal and detecting magnetic defects therefrom.
Claim 7
Dependent Claim
43 words
The system of claim 5, wherein the first type of surface disturbance is a protrusion, and wherein the first processing path and the magnetic environment processing path cooperatively determine whether the protrusion is intrinsic to the medium or a particle on the medium.
Claim 8
Dependent Claim
18 words
The system of claim 1 in combination with a head and a medium moving relative to said head.
Claim 9
Dependent Claim
17 words
The combination of claim 7 wherein said medium is a data storage medium accessed by said head.
Claim 10
Dependent Claim
26 words
The system of claim 1, wherein the active first signal comprises a first pulse from the first pulse generator, the first pulse having a predetermined width.
Claim 11
Dependent Claim
30 words
The system of claim 9, wherein the active second signal comprises a second pulse from the second pulse generator in the second path, the second pulse having a predetermined width.
Claim 12
Dependent Claim
41 words
The system of claim 10, wherein the first processing path includes a first gate having first and second inputs for receiving the first and second pulses respectively, the first gate providing a first output when only the first pulse is active.
Claim 13
Dependent Claim
41 words
The system of claim 11, wherein the second processing path includes a second gate having first and second inputs for receiving the first and second pulses respectively, the second gate providing a second output when only the second pulse is active.
Claim 14
Dependent Claim
29 words
The system of claim 12, wherein the first criteria comprises the input signal rising above the first reference level and the first type of surface disturbance is a recess.
Claim 15
Dependent Claim
28 words
The system of claim 13, wherein the second criteria comprises the input signal falling below the second level and the second type of surface disturbance is a protrusion.
Claim 16
Dependent Claim
62 words
The system of claim 10, further comprising a circuit for determining whether the input signal meets a third criteria, the circuit having first and second inputs for receiving the first and second pulses respectively, the circuit providing a third output if coincident first and second pulses are received thereby, the third criteria corresponding to an interaction between the head and the medium.
Claim 17
Independent Claim
135 words
A system for identifying surface conditions of a medium moving relative to a head, comprising: an input node for receiving an input signal, the input signal being representative of a thermal environment over the medium monitored by said head; a first processing path coupled to the input node for determining whether the input signal received therefrom meets a first criteria, the first criteria corresponding to a first type of surface disturbance on the medium: a second processing path coupled to the input node for determining whether the input signal received therefrom meets a second criteria, the second criteria corresponding to a second type of surface disturbance on the medium; and a circuit for determining whether the input signal meets a third criteria, the third criteria corresponding to an interaction between the head and the medium.
Claim 18
Independent Claim
135 words
A system for identifying surface conditions of a medium moving relative to a head, comprising: an input node for receiving an input signal, the input signal being representative of a thermal environment over the medium monitored by said head; a first processing path coupled to the input node for determining whether the input signal received therefrom meets a first criteria, the first criteria corresponding to a first type of surface disturbance on the medium: a second processing path coupled to the input node for determining whether the input signal received therefrom meets a second criteria, the second criteria corresponding to a second type of surface disturbance on the medium; and a circuit for determining whether the input signal meets a third criteria, the third criteria corresponding to an interaction between the head and the medium.
Claim 19
Dependent Claim
58 words
The system of claim 16, wherein the first processing path provides an active first signal indicative of the input signal rising above/falling below a first reference level comprising said first criteria; and wherein the second processing path provides an active second signal indicative of the input signal falling below/rising above a second reference level comprising said second criteria.
Claim 20
Dependent Claim
50 words
The system of claim 17, wherein the first path includes: a comparator coupled to the input node for receiving the input signal therefrom, the comparator for comparing the input signal to the first reference level; and a first pulse generator, triggered by the comparator, for providing the active first signal.
Claim 21
Dependent Claim
25 words
The system of claim 18, wherein the active first signal comprises a first pulse from the pulse generator, the first pulse having a predetermined width.
Claim 22
Dependent Claim
30 words
The system of claim 19, wherein the active second signal comprises a second pulse from a second pulse generator in the second path, the second pulse having a predetermined width.
Claim 23
Dependent Claim
47 words
The system of claim 20, wherein the circuit for determining whether the input signal meets a third criteria has first and second inputs for receiving the first and second pulses respectively, the circuit providing a third output signal if coincident first and second pulses are received thereby.
Claim 24
Dependent Claim
41 words
The system of claim 21, wherein the first processing path includes a first gate having first and second inputs for receiving the first and second pulses respectively, the first gate providing a first output when only the first pulse is active.
Claim 25
Dependent Claim
44 words
The system of claim 22, wherein the first gate comprises an AND gate, the first input thereof coupled to the output of the first pulse generator and the second input thereof comprising an inverted input coupled to the output of the second pulse generator.
Claim 26
Dependent Claim
41 words
The system of claim 23, wherein the second processing path includes a second gate having first and second inputs for receiving the first and second pulses respectively, the second gate providing a second output when only the second pulse is active.
Claim 27
Dependent Claim
44 words
The system of claim 24, wherein the second gate comprises an AND gate, the first input thereof coupled to the output of the second pulse generator and the second input thereof comprising an inverted input coupled to the output of the first pulse generator.
Claim 28
Dependent Claim
29 words
The system of claim 25, wherein the first criteria comprises the input signal rising above the first reference level and the first type of surface disturbance is a recess.
Claim 29
Dependent Claim
28 words
The system of claim 26, wherein the second criteria comprises the input signal falling below the second level and the second type of surface disturbance is a protrusion.
Claim 30
Dependent Claim
15 words
The system of claim 27, wherein the third criteria comprises an oscillating input signal level.
Claim 31
Dependent Claim
38 words
The system of claim 17, wherein the first processing path provides a first output signal when the first signal is active; and wherein the second processing path provides a second output signal when the second signal is active.
Claim 32
Dependent Claim
34 words
The system of claim 16, wherein the first criteria comprises a high/low input signal level and the second criteria comprises a low/high input signal level, and the third criteria comprises an oscillating signal level.
Claim 33
Dependent Claim
21 words
The system of claim 30, wherein the oscillating signal level oscillates between two input signal levels within a predetermined time period.
Claim 34
Dependent Claim
49 words
The system of claim 16, further comprising: another input node for receiving another input signal, the another input signal being representative of a magnetic environment on the moving medium; and a magnetic environment processing path for determining whether the another input signal meets the first, second or third criteria.
Claim 35
Independent Claim
102 words
A system for identifying surface conditions of a medium moving relative to a head, comprising: an input node for receiving an input signal, the input signal being representative of a thermal environment over the medium monitored by said head; a first processing path coupled to the input node for determining whether the input signal received therefrom meets a first criteria, the first criteria corresponding to a first type of surface disturbance on the medium; and a circuit for determining whether the input signal received therefrom meets a second criteria, the second criteria corresponding to an interaction between the head and the medium.
Claim 36
Independent Claim
102 words
A system for identifying surface conditions of a medium moving relative to a head, comprising: an input node for receiving an input signal, the input signal being representative of a thermal environment over the medium monitored by said head; a first processing path coupled to the input node for determining whether the input signal received therefrom meets a first criteria, the first criteria corresponding to a first type of surface disturbance on the medium; and a circuit for determining whether the input signal received therefrom meets a second criteria, the second criteria corresponding to an interaction between the head and the medium.
Claim 37
Dependent Claim
35 words
The system of claim 33, further comprising: a second processing path for determining whether the input signal meets a third criteria, the third criteria corresponding to a second type of surface disturbance on the medium.
Claim 38
Dependent Claim
34 words
The system of claim 34, wherein the first criteria comprises a high/low input signal level and the second criteria comprises an oscillating signal level and the third criteria comprises a low/high input signal level.
Claim 39
Dependent Claim
21 words
The system of claim 35, wherein the oscillating signal level oscillates between two input signal levels within a predetermined time period.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-09-21 | 2002-03-23 | 2002-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-21 | 2006-03-23 | 2006-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-21 | 2010-03-23 | 2010-09-22 | $7700.00 | Window Closed / Lapsed |