US3777186A
Expired / Lapsed
US
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Charge transfer logic device
Assignee: International Business Machines Corp
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Filing: 1972-07-03
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Granted: 1973-12-04
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Expires: 1992-07-03
Abstract
Abstract A monolithic charge transfer device wherein logic functions are performed is disclosed. A logical AND gate is provided which utilizes a quantized potential well formed in a surface region of a semi-conducting, or semi-insulating, material by a pattern of control electrodes. Various applications of the AND gate structure provide additional logical functions of Exclusive OR and Exclusive NOR gates.
Inventors
- 👤 W Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:08
CPC Classifications
H; H03; H03K; H03K19/00; H03K19/02; H03K19/08; H03K19/0806; G; G11; G11C; G11C19/00; G11C19/28; G11C19/282; H10; H10D; H10D44/00; H10D44/40; H10D44/45; H10D44/472
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
252 words
In charge transfer apparatus of the type used for storage and transfer of binary data units in localized potential wells periodically induced in a storage medium, wherein the presence of a packet of charge represents a first logical state and the absence of charge represents a second logical state a logical gate comprising: first potential inducing means for periodically inducing a first and a second potential well in spaced relation in said storage medium, said potential wells being connected by a charge transfer path capable of allowing charge to transfer from said first potential well to said second potential well during a first time period, said charge transfer path including a potential barrier of less magnitude than said first and second potential wells to provide isolation between said first potential wells and to provide said first potential well with a charge capacity equal to at least one packet of charge, data input means adjacent to said first potential well for periodically allowing the transfer of at least two separate binary data units into said first potential well during said first time period, said charge transfer path allowing the transfer of any quantity of charge in excess of the capacity of said first potential well to be transferred over said potential barrier to said second potential well to provide an isolated charge in said second potential well whenever said data input means provides a quantity of charge, representive of said first logical state, in excess of the capacity of said first potential well.
Claim 2
Dependent Claim
252 words
In charge transfer apparatus of the type used for storage and transfer of binary data units in localized potential wells periodically induced in a storage medium, wherein the presence of a packet of charge represents a first logical state and the absence of charge represents a second logical state a logical gate comprising: first potential inducing means for periodically inducing a first and a second potential well in spaced relation in said storage medium, said potential wells being connected by a charge transfer path capable of allowing charge to transfer from said first potential well to said second potential well during a first time period, said charge transfer path including a potential barrier of less magnitude than said first and second potential wells to provide isolation between said first potential wells and to provide said first potential well with a charge capacity equal to at least one packet of charge, data input means adjacent to said first potential well for periodically allowing the transfer of at least two separate binary data units into said first potential well during said first time period, said charge transfer path allowing the transfer of any quantity of charge in excess of the capacity of said first potential well to be transferred over said potential barrier to said second potential well to provide an isolated charge in said second potential well whenever said data input means provides a quantity of charge, representive of said first logical state, in excess of the capacity of said first potential well.
Claim 3
Dependent Claim
38 words
The apparatus of claim 1 further including: means responsive to the charge condition of said second potential well during a second time period for determining the logical condition of said data input means during said first time period.
Claim 4
Dependent Claim
40 words
The apparatus of claim 1 further including: second potential inducing adjacent to said second potential well for periodically inducing, during at least a second time period, a third potential well for receiving the charge contents of said second potential well.
Claim 5
Dependent Claim
82 words
The apparatus of claim 1 wherein said first potential well has a capacity of N-1 packets of charge, where N is an integer greater than 1, and further wherein said data input means is capable of providing N separate binary data units to said first potential well during said first time period, said apparatus acting as a logical AND gate by providing a charge in said second potential well only when N packets of charge are transferred to said first potential well.
Claim 6
Dependent Claim
32 words
The apparatus of claim 1 wherein said first and second potential wells and said charge transfer path are simultaneously created by two spaced electrodes adjacent to the surface of said storage medium.
Claim 7
Dependent Claim
64 words
The apparatus of claim 1 wherein said first and second potential wells are induced by application of a first potential to a first and second spaced location on the surface of said storage medium and said charge transfer path is induced by application of a second potential of smaller magnitude than said first potential in a third location intermediate said first and second locations.
Claim 8
Dependent Claim
52 words
The apparatus of claim 1 wherein said storage medium is a semiconductor material and said first potential inducing means comprises a metallic electrode having a periodic electrical potential applied thereto, portions of said electrode being spaced from the surface of said semiconductor material by at least two different thicknesses of insulating material.
Claim 9
Dependent Claim
31 words
The apparatus of claim 1 including means adjacent to said first potential well for dissipating any charge quantity remaining in said first potential well after said first time period has passed.
Claim 10
Dependent Claim
38 words
The apparatus of claim 1 including means adjacent to said first potential well for utilizing any charge present in said first potential well after said first time period has passed as the output of a logical OR function.
Claim 11
Dependent Claim
180 words
The apparatus of claim 3 wherein said first potential well has a capacity of one packet of charge and said data input means is capable of allowing the transfer of two separate binary data units said apparatus further including: charge sensing means in sensing relation to said second potential inducing means for sensing the charge condition of said third potential well; control means responsive to said charge sensing means for controlling the transfer of charge in said first potential well to an output means, said control means being capable of inducing a potential well sufficient to transfer a packet of charge from said first potential well only when substantially no charge quantity is sensed by said sensing means; and output means adjacent to said control means for inducing a fourth potential well for receiving a transferred charge from said first potential well, said apparatus acting as a logical Exclusive OR gate by providing a charge in said fourth potential well only when a single packet of charge has been transferred to said first potential well during said first time period.
Claim 12
Dependent Claim
15 words
The apparatus of claim 10 wherein said sensing means is an electrically floating metallic electrode.
Claim 13
Dependent Claim
31 words
The apparatus of claim 10 wherein said storage medium is a semiconductor of a first conductivity type and said sensing means is a diffused semiconductor region of a second conductivity type.
Claim 14
Dependent Claim
224 words
The apparatus of claim 1 wherein said first potential well has a capacity of more than one and less than two packets of charge and said data input means is capable of allowing the transfer of two separate binary data units to said first potential well during said first time period, said apparatus further including; second potential inducing means adjacent to said first potential well for periodically indUcing a third potential well for receiving the charge contents of said first potential well; charge sensing means in sensing relation to said third potential well for sensing the presence of charge in said third potential well; charge injection means for providing a source of charge; and control means responsive to said charge sensing means, said control means being adjacent to both said charge injection means and said second potential well to control the transfer of charge from said injection means to said second potential well on the condition that substantially no charge is sensed by said sensing means, a charge being available in said second potential well on the condition that no charge has been introduced into said first potential well and on the condition that two charges have been introduced into said first potential well, said apparatus providing a charge in said second potential well representative of the output of a logical Exclusive NOR gate.
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) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |