US4556920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reproduction device
Assignee: Canon Inc
•
Filing: 1983-12-08
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Granted: 1985-12-03
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Expires: 2003-12-08
Abstract
Abstract In the disclosed device first and second reproduction heads contact two recording tracks on a recording medium, and a tracking control controls their tracking such that there is no difference in outputs between the first and second reproduction heads. The distance between the two reproduction heads is set so that tracking deviations from a normal course cause the outputs of the two heads to differ according to the direction and amount of the deviation.
Inventors
- 👤 Masaya Maeda
- 👤 Masahiro Takei
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:51
CPC Classifications
G; G11; G11B; G11B21/00; G11B21/02; G11B21/10; G11B21/103; G11B5/00; G11B5/48; G11B5/58; G11B5/584; G11B5/588; G11B5/592
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
149 words
A reproduction device comprising: first and second reproduction heads respectively face-contacting two recording tracks on a recording medium; and tracking control means for eliminating a difference in reproduction outputs of the first and second reproduction heads, the first and second reproduction heads having widths different from widths of recording tracks, and a distance Y between adjacent edges of first and second head gaps in the direction transverse to the tracks being set against a distance GW between adjacent edges of adjoining tracks in the direction transverse to the tracks and a track pitch TP having approximately the following relation: Y=GW+mTP(m=0, 1, 2 . . . ), or, a distance X between the other edges of each head gap transverse to the tracks having approximately the relation shown below relative to the track width TW, the distance GW and the track pitch TP: X=2TW+GW+nTP(n=0, 1, 2 . . . ).
Claim 2
Dependent Claim
149 words
A reproduction device comprising: first and second reproduction heads respectively face-contacting two recording tracks on a recording medium; and tracking control means for eliminating a difference in reproduction outputs of the first and second reproduction heads, the first and second reproduction heads having widths different from widths of recording tracks, and a distance Y between adjacent edges of first and second head gaps in the direction transverse to the tracks being set against a distance GW between adjacent edges of adjoining tracks in the direction transverse to the tracks and a track pitch TP having approximately the following relation: Y=GW+mTP(m=0, 1, 2 . . . ), or, a distance X between the other edges of each head gap transverse to the tracks having approximately the relation shown below relative to the track width TW, the distance GW and the track pitch TP: X=2TW+GW+nTP(n=0, 1, 2 . . . ).
Claim 3
Dependent Claim
25 words
A reproduction device according to claim 1, wherein widths of the first and second reproduction heads are set wider than widths of the recording tracks.
Claim 4
Dependent Claim
13 words
A reproduction device according to claim 1, wherein, is set m=0, is set.
Claim 5
Dependent Claim
13 words
A reproduction device according to claim 1, wherein, is set n=0, is set.
Claim 6
Dependent Claim
19 words
A reproduction device according to claim 1, wherein the first and second reproduction heads have respectively different azimuth angles.
Claim 7
Dependent Claim
20 words
A reproduction device according to claim 1, wherein gaps of the first and second reproduction heads deviate from each other.
Claim 8
Dependent Claim
26 words
A reproduction device according to claim 1, wherein the tracking control means has a bi-morph plate on which the first and second reproduction heads are mounted.
Claim 9
Dependent Claim
35 words
A reproduction device according to claim 1, wherein the tracking control means has two automatic gain control circuits to respectively amplify outputs of the first and second reproduction heads and control variations of gains thereof.
Claim 10
Dependent Claim
26 words
A reproduction device according to claim 1, wherein the recording medium is a magnetic recording medium, and the first and second reproduction heads are magnetic heads.
Claim 11
Dependent Claim
15 words
A reproduction device according to claim 1, wherein the recording medium has a circular shape.
Claim 12
Dependent Claim
75 words
A reproduction device comprising: first and second reproduction heads respectively face-contacting two recording tracks on a recording medium; first and second amplifiers to amplify reproduction outputs of the first and second reproduction heads; tracking control means to reduce differences in the outputs of the first and second amplifiers to zero; and gain adjusting means to adjust gains of the first and second amplifiers to compensate for reproduction characteristics of the first and second reproduction heads.
Claim 13
Dependent Claim
75 words
A reproduction device comprising: first and second reproduction heads respectively face-contacting two recording tracks on a recording medium; first and second amplifiers to amplify reproduction outputs of the first and second reproduction heads; tracking control means to reduce differences in the outputs of the first and second amplifiers to zero; and gain adjusting means to adjust gains of the first and second amplifiers to compensate for reproduction characteristics of the first and second reproduction heads.
Claim 14
Dependent Claim
133 words
A reproduction device according to claim 11, wherein the first and second reproduction heads are arranged so that widths of said heads are different from the widths of the recording tracks, and a distance Y between adjacent edges of the first and second reproduction head gaps in the direction transverse to the track have approximately the following relation relative to a distance GW between adjacent edges of adjoining tracks in the direction transverse to the tracks, and the track pitch TP: Y=GW+mTP(m=0, 1, 2 . . . ), or a distance X between the other edges of each head gap in the direction transverse to the tracks have approximately the following relation relative to the track width TW, the distance GW, and the track pitch TP: X=2TW+GW+nTP(n=0, 1, 2 . . . ).
Claim 15
Dependent Claim
25 words
A reproduction device according to claim 12, wherein widths of the first and second reproduction heads are wider than the widths of the recording tracks.
Claim 16
Dependent Claim
13 words
A reproduction device according to claim 12, wherein, is set m=0, is set.
Claim 17
Dependent Claim
13 words
A reproduction device according to claim 12, wherein, is set n=0, is set.
Claim 18
Dependent Claim
18 words
A reproduction device according to claim 12, wherein the first and second reproduction heads have different azimuth angles.
Claim 19
Dependent Claim
20 words
A reproduction device according to claim 12, wherein gaps of the first and second reproduction heads deviate from each other.
Claim 20
Dependent Claim
26 words
A reproduction device according to claim 12, wherein the tracking control means has a bi-morph plate on which the first and second reproduction heads are mounted.
Claim 21
Dependent Claim
26 words
A reproduction device according to claim 11, wherein the recording medium is a magnetic recording medium and the first and second reproduction heads are magnetic heads.
Claim 22
Dependent Claim
15 words
A reproduction device according to claim 11, wherein the recording medium has a circular shape.
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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) | 1988-12-02 | 1989-06-03 | 1989-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-02 | 1993-06-03 | 1993-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-02 | 1997-06-03 | 1997-12-03 | $7700.00 | Window Closed / Lapsed |