EP0055017A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Magnetic bubble memory cassette
Assignee: Fujitsu Ltd
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Filing: 1981-10-30
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Granted: —
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Expires: 2001-10-30
Abstract
Abstract A magnetic bubble memory cassette includes a magnetic bubble memory chip, a package (35) accommodating the chip, and upper and lower casing members (31, 32). In the cassette, two magnetic shield plates (42, 43) are provided adjacent to the inner surfaces of the upper and lower casing members respectively.
Inventors
- 👤 Toshiaki Sukeda
- 👤 Shiro Naoi
- 👤 Harumi Maegawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 08:40
CPC Classifications
H; H05; H05K; H05K5/00; H05K5/02; H05K5/0256; H05K5/026; G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/085
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
113 words
A magnetic bubble memory cassette comprising a printed-circuit board on which is mounted a package containing a magnetic bubble memory chip, which package also contains coils surrounding the magnetic bubble memory chip, for applying a rotating magnetic field to the magnetic bubble memory chip, and permanent magnet means arranged to apply a bias magnetic field to the magnetic bubble memory chip; the cassette further comprising a housing structure accommodating the printed-circuit board and the said package; and there being two plate-form magnetic shielding parts (42,43) disposed respectively, within the said housing structure (31,32), to opposite sides of the said package so as to extend substantially parallel to the magnetic bubble memory chip therebetween.
Claim 2
Dependent Claim
113 words
A magnetic bubble memory cassette comprising a printed-circuit board on which is mounted a package containing a magnetic bubble memory chip, which package also contains coils surrounding the magnetic bubble memory chip, for applying a rotating magnetic field to the magnetic bubble memory chip, and permanent magnet means arranged to apply a bias magnetic field to the magnetic bubble memory chip; the cassette further comprising a housing structure accommodating the printed-circuit board and the said package; and there being two plate-form magnetic shielding parts (42,43) disposed respectively, within the said housing structure (31,32), to opposite sides of the said package so as to extend substantially parallel to the magnetic bubble memory chip therebetween.
Claim 3
Dependent Claim
21 words
A cassette as claimed in claim 1, wherein each of the plate-form magnetic shielding parts is spaced from the said package.
Claim 4
Dependent Claim
43 words
A cassette as claimed in claim 1 or 2, wherein the plate-form magnetic shielding parts are base portions of respective magnetic shielding members, one of which has side-wall portions which project across the interior of the cassette towards the other magnetic shielding member.
Claim 5
Dependent Claim
34 words
A cassette as claimed in claim 3, wherein the said other magnetic shielding member has side-wall portions which project, across the interior of the cassette, towards the said one of the magnetic shielding members.
Claim 6
Dependent Claim
45 words
A cassette as claimed in claim 4, wherein such side-wall portions of the said one magnetic shielding member overlap with such side-wall portions of the other magnetic shielding member, so that the said package is surrounded by the material of the said magnetic shielding members.
Claim 7
Dependent Claim
19 words
A cassette as claimed in any preceding claim, wherein the said magnetic shielding parts are made of a permalloy.
Claim 8
Dependent Claim
23 words
A cassette as claimed in any one of claims 1 to 5, wherein the said magnetic shielding parts are made of pure iron.
Claim 9
Dependent Claim
64 words
A-z-ssette as claimed in any preceding claim, wherein the said housing structure comprises first and second opposed casing members having respective edge portions which abut against one another so that the first and second casing members together surround the said package and printed-circuit board therebetween, the said magnetic shielding parts being fixed respectively against inner surfaces of the said first and second casing members.
Claim 10
Dependent Claim
41 words
A cassette as claimed in any preceding claim, wherein the said housing structure is formed with at least one aperture for exposing an outer surface portion of at least one of the said magnetic shielding parts to air outside the cassette.
Claim 11
Dependent Claim
25 words
A cassette as claimed in claim 9, wherein heat dissipating means are arranged between the said package and one of the said magnetic shielding parts.
Claim 12
Dependent Claim
32 words
A cassette as claimed in claim 10, wherein the said heat dissipating means are arranged at an upper surface of the said package, which surface is remote from the said printed-circuit board.
Claim 13
Dependent Claim
25 words
A cassette as claimed in claim 10 or 11, wherein the said heat dissipating means comprise a plate made of material of high thermal conductivity.
Claim 14
Dependent Claim
24 words
A cassette as claimed in claim 10 or 11, wherein the said heat dissipating means comprise fins made of material of high thermal conductivity.
Claim 15
Dependent Claim
24 words
A cassette as claimed in claim 12 or 13, wherein the material of the said heat dissipating means is aluminium or an aluminium alloy.
Claim 16
Dependent Claim
41 words
A cassette as claimed in any preceding claim, wherein the said housing structure is made of a mixture of materials, one of which is a carbon material, such as to protect the magnetic bubble memory chip against damage from electrostatic effects.
Claim 17
Independent Claim
32 words
A device as claimed in any preceding claim, wherein the said housing structure is coated with a metal, so as to protect the magnetic bubble memory chip against damage from electrostatic effects.
References Cited (Backward Citations)
US4156934A
Cited
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