US3821582A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for return beam readout through a matrix electron lens
Assignee: General Electric Co
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Filing: 1972-10-02
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Granted: 1974-06-28
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Expires: 1992-10-02
Abstract
Abstract An electron beam-addressable memory apparatus and method for writing information on a memory target and reading information stored thereon are disclosed. Readout of stored information is achieved by scanning a primary electron beam across the target and detecting the secondary electrons emitted therefrom. The primary electron beam is directed first to a specific lenslet of a matrix electron lens by a coarse deflection assembly and then to a precise location on the target by a fine deflection assembly. Secondary emission electrons emanating from the surface of the target as a result of the primary electron beam are focussed back to the matrix electron lens and then are directed along a trajectory substantially similar to that of the primary electron beam to an electron detector. Since the number of detected electrons is modulated by the information stored on the target, information representative of digital data is conveniently stored and efficiently read out from the memory.
Inventors
- 👤 W Hughes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:21
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/46; H01J29/58; G; G11; G11C; G11C11/00; G11C11/21; G11C11/23; G11C13/00; G11C13/04; G11C13/048; H01J29/70; H01J29/72; H01J29/76; H01J31/00; H01J31/08; H01J31/58; H01J31/60
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
166 words
An electron beam-addressable memory system comprising: an electron source for producing a beam of electrons; a data storage target disposed in the path of said beam for storing information thereon; a matrix electron lens disposed in the path of said beam and positioned adjacent to said storage target, said lens comprising a pair of spaced parallel lens plates each having a plurality of lenslets therein for focussing said beam on said target; coarse deflection means positioned between said electron source and said lens for directing said beam to a specific lenslet; fine deflection means positioned between said lens and said storage target for directing said beam to a specific point of impingement on said storage target, said target emitting secondary electrons in response to said beam impinging on said target; means for returning said secondary emission electrons along a path substantially similar to said electron beam; and means for detecting said secondary emission electrons and providing an output signal proportional to the detected secondary emission electrons.
Claim 2
Dependent Claim
166 words
An electron beam-addressable memory system comprising: an electron source for producing a beam of electrons; a data storage target disposed in the path of said beam for storing information thereon; a matrix electron lens disposed in the path of said beam and positioned adjacent to said storage target, said lens comprising a pair of spaced parallel lens plates each having a plurality of lenslets therein for focussing said beam on said target; coarse deflection means positioned between said electron source and said lens for directing said beam to a specific lenslet; fine deflection means positioned between said lens and said storage target for directing said beam to a specific point of impingement on said storage target, said target emitting secondary electrons in response to said beam impinging on said target; means for returning said secondary emission electrons along a path substantially similar to said electron beam; and means for detecting said secondary emission electrons and providing an output signal proportional to the detected secondary emission electrons.
Claim 3
Dependent Claim
31 words
The memory system of claim 1 wherein information stored on said target is representative of digital information and said secondary emission electrons are emitted in proportional response to said stored information.
Claim 4
Dependent Claim
39 words
The memory system of claim 1 further comprising: means establishing a magnetic field along the axis of said electron beam, said magnetic field relaying said focussed electron beam existing from said lenslet to said target with a single node.
Claim 5
Dependent Claim
32 words
The memory system of claim 3 further comprising: means biasing said parallel lens plates to produce a decelerating electric field for decelerating and focussing said electron beam in front of said lenslet.
Claim 6
Dependent Claim
27 words
The memory system of claim 4 wherein said secondary electrons are directed to said detecting means under the influence of said magnetic field and said electric field.
Claim 7
Dependent Claim
32 words
The memory system of claim 5 wherein said secondary electrons emitted from the target surface are directed to a lenslet of said matrix electron lens with a multinode focus of varying pitch.
Claim 8
Dependent Claim
17 words
The memory system of claim 3 wherein said electron beam impinges on said target substantially normal thereto.
Claim 9
Dependent Claim
46 words
The memory system of claim 5 wheRe said means for detecting comprises a semiconductor detector positioned along the path of said electron beam between said coarse deflection means and said electron source, said detector having an aperture therein for the passage of said electron beam therethrough.
Claim 10
Dependent Claim
25 words
The memory system of claim 4 wherein said means biasing said parallel lens plates produces an accelerating ratio in the range of 3 to 5.
Claim 11
Independent Claim
68 words
A method of reading out information stored on a target surface with an electron beam, said method comprising the steps of forming a beam of electrons; focussing said beam of electrons on said target, said target emitting secondary electrons in response to said beam of electrons; returning said secondary emission electrons along a path substantially similar to said electron beam; and detecting said secondary electrons along said path.
Claim 12
Independent Claim
68 words
A method of reading out information stored on a target surface with an electron beam, said method comprising the steps of forming a beam of electrons; focussing said beam of electrons on said target, said target emitting secondary electrons in response to said beam of electrons; returning said secondary emission electrons along a path substantially similar to said electron beam; and detecting said secondary electrons along said path.
Claim 13
Dependent Claim
52 words
The method of claim 10 wherein the step of focussing comprises: coarsely deflecting said beam of electrons to a lenslet of a matrix electron lens; decelerating said beam of electrons with said matrix electron lens; and finely deflecting said beam of electrons to a specific point of impingement on said target surface.
Claim 14
Dependent Claim
21 words
The method of claim 11 wherein said secondary emission electrons are emitted in proportional response to information stored on said target.
Claim 15
Dependent Claim
44 words
The method of claim 12 wherein the step of returning said secondary emission electrons comprises: establishing a magnetic field along the axis of said electron beam for directing said secondary emission electrons to said matrix electron lens with a multinode focus of varying pitch.
Claim 16
Dependent Claim
33 words
The method of claim 13 further comprising: biasing said matrix electron lens to produce a decelerating electric field for said beam of electrons and an accelerating electric field for said secondary emission electrons.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |