US4577251A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic disc cassette having disc flattening means
Assignee: Canon Electronics Inc
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Filing: 1983-03-08
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Granted: 1986-03-18
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Expires: 2003-03-08
Abstract
Abstract A cassette for accommodating a magnetic recording medium which includes a pressing member adjacent a head window pressing the recording/reproducing surface of a magnetic recording medium thereby flattening its surface. Spacing loss between the magnetic disc and the magnetic head and track deviation error are prevented thereby permitting precise recording and reproducing operations.
Inventors
- 👤 Shinichi Okada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:43
CPC Classifications
G; G11; G11B; G11B23/00; G11B23/02; G11B23/03; G11B23/033; G11B23/0332; G11B17/00; G11B17/32
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
175 words
A casette for accommodating a magnetic recording medium in the form of a thin disc, said cassette being adapted for insertion in a magnetic recording/reproducing apparatus having a magnetic head, comprising: a case having first and second substantially flat surfaces defining a cavity therebetween wherein said disc is positioned for rotation in a given direction about an axis normal to said flat surfaces, at least one of said flat surfaces having a window therein for exposing a surface of said disc to said magnetic head, said window having first and second opposite edges; and a pressing member secured to a flat surface of said case adjacent an edge of said window and protruding into said window to resiliently press on a surface of said disc thereby flattening said surface, said pressing member including a pressing piece made of a cushioning material for contacting the surface of said disc and a resilient supporting member interposed between said case and said pressing piece for supporting said pressing piece and urging it against the surface of said disc.
Claim 2
Dependent Claim
175 words
A casette for accommodating a magnetic recording medium in the form of a thin disc, said cassette being adapted for insertion in a magnetic recording/reproducing apparatus having a magnetic head, comprising: a case having first and second substantially flat surfaces defining a cavity therebetween wherein said disc is positioned for rotation in a given direction about an axis normal to said flat surfaces, at least one of said flat surfaces having a window therein for exposing a surface of said disc to said magnetic head, said window having first and second opposite edges; and a pressing member secured to a flat surface of said case adjacent an edge of said window and protruding into said window to resiliently press on a surface of said disc thereby flattening said surface, said pressing member including a pressing piece made of a cushioning material for contacting the surface of said disc and a resilient supporting member interposed between said case and said pressing piece for supporting said pressing piece and urging it against the surface of said disc.
Claim 3
Dependent Claim
49 words
A cassette as claimed in claim 1, wherein said pressing member is secured to said flat surface adjacent the first edge of said window, a given point on said magnetic disc reaching said first edge before passing under said window when said disc is rotated in said given direction.
Claim 4
Dependent Claim
93 words
A cassette as claimed in claim 2, which further includes a second pressing member secured to said flat surface adjacent the second edge of said window, said second pressing member including a second pressing piece made of a cushioning material for contacting the surface of said disc and a second resilient supporting member interposed between said case and said second pressing piece for supporting said second pressing piece and urging it against the surface of said disc, the given point on said magnetic disc reaching said second edge after passing under said window.
Claim 5
Dependent Claim
107 words
A cassette as claimed in claim 2, which further includes a second pressing member secured to a flat surface of said case and resiliently pressing the surface of said disc opposite the surface pressed by said first mentioned pressing member, said second pressing member including a second pressing piece made of a cushioning material for contacting the surface of said disc and a second resilient supporting member interposed between said case and said second pressing piece for supporting said second pressing piece and urging it against the surface of said disc, both of said pressing members pressing both surfaces of said disc thereby flattening the surfaces thereof.
Claim 6
Dependent Claim
128 words
A cassette for accommodating a magnetic recording medium in the form of a thin disc, said cassette being adapted for insertion in a magnetic recording/reproducing apparatus having a magnetic head, comprising: a case having first and second substantially flat surfaces defining a cavity therebetween wherein said disc is positioned for rotation in a given direction about an axis normal to said flat surfaces, at least one of said flat surfaces having a window therein for exposing a surface of said disc to said magnetic head, said window having first and second opposite edges; a shutter movably attached to said case for opening and closing said opening; and a pressing member secured to said shutter, said pressing member resiliently pressing a surface of said disc thereby flattening said surface.
Claim 7
Dependent Claim
128 words
A cassette for accommodating a magnetic recording medium in the form of a thin disc, said cassette being adapted for insertion in a magnetic recording/reproducing apparatus having a magnetic head, comprising: a case having first and second substantially flat surfaces defining a cavity therebetween wherein said disc is positioned for rotation in a given direction about an axis normal to said flat surfaces, at least one of said flat surfaces having a window therein for exposing a surface of said disc to said magnetic head, said window having first and second opposite edges; a shutter movably attached to said case for opening and closing said opening; and a pressing member secured to said shutter, said pressing member resiliently pressing a surface of said disc thereby flattening said surface.
Claim 8
Dependent Claim
17 words
A cassette as claimed in claim 5, wherein said pressing member is made of an elastic material.
Claim 9
Dependent Claim
27 words
A cassette as claimed in claim 5, wherein said pressing member includes a protrudent portion protruding toward said disc surface comprising an integral part of said shutter.
Claim 10
Dependent Claim
54 words
A cassette as claimed in claim 5, wherein said pressing member is located on a portion of said shutter which a given point on said magnetic disc reaches before passing under said window when said disc is rotated in said given direction and said shutter is in a position whereby said window is open.
Claim 11
Dependent Claim
56 words
A cassette as claimed in claim 8, which further includes a second pressing member secured to a flat surface of said case and resiliently pressing the surface of said disc opposite the surface pressed by said first mentioned pressing member, both of said pressing members pressing both surfaces of said disc thereby flattening the surfaces thereof.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-03-17 | 1989-09-16 | 1990-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-17 | 1993-09-16 | 1994-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-17 | 1997-09-16 | 1998-03-18 | $7700.00 | Window Closed / Lapsed |