US3733590A
Expired / Lapsed
US
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Optimum electrode configuration ceramic memories with ceramic motor element and mechanical damping
Assignee: Unisys Corp
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Filing: 1971-04-15
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Granted: 1973-05-15
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Expires: 1991-04-15
Abstract
Abstract Ceramic memories utilize an electrostrictive ceramic motor element mechanically bonded to a ferroelectric ceramic memory element. Signal or ''''bit'''' electrodes are disposed over only the portion of the memory element to which maximum stress is transmitted by the motor element. In disc shaped embodiments, the bit electrodes are restricted to the central 50 percent of the memory device surface; in rectangular embodiments, the bit electrodes are disposed along the longitudinal centerline of the memory element and have a width less than one-half that of the memory device. In other embodiments, a portion of the memory element ceramic slab performs a motor function, or alternatively, dual motor elements are employed. To prevent ringing, each memory device may employ a damping electrode fabricated of an electrically conductive alloy exhibiting mechanical damping capacity. Alternatively, the device may be mounted to a substrate by means of an energy absorbing material, or may have an edge mechanically clamped or adhesively bonded to the substrate to prevent ringing.
Inventors
- 👤 A Kaufman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:40
CPC Classifications
G; G11; G11C; G11C8/00; G11C8/005; G11C11/00; G11C11/21; G11C11/22; G11C11/56; G11C11/5657; H; H04; H04R; H04R17/00; H04R17/04; H04R17/08
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
86 words
A two layer ceramic bender memory including: a. a motor element mechanically bonded to a memory element having one or more bit electrodes, b. the area of said bit electrodes being less than about onehalf the area of said motor element, c. said bit electrodes being disposed adjacent the center of said memory element so that the data storage regions of said memory element are restricted only to the region receiving maximum stress, and the ''''sink'''' effect of the remainder of said memory element is minimized.
Claim 2
Dependent Claim
86 words
A two layer ceramic bender memory including: a. a motor element mechanically bonded to a memory element having one or more bit electrodes, b. the area of said bit electrodes being less than about onehalf the area of said motor element, c. said bit electrodes being disposed adjacent the center of said memory element so that the data storage regions of said memory element are restricted only to the region receiving maximum stress, and the ''''sink'''' effect of the remainder of said memory element is minimized.
Claim 3
Dependent Claim
17 words
A ceramic memory according to claim 1 further comprising: d. means for mechanically damping said memory element.
Claim 4
Dependent Claim
54 words
In a ceramic memory of the type including a motor element of electrostrictive material, a memory element of ferroelectric ceramic material mounted to be stressed by said motor element, the improvement comprising a damping electrode disposed between said motor and memory elements, said electrode comprising an electrically conductive alloy exhibiting significant specific damping capacity.
Claim 5
Dependent Claim
54 words
In a ceramic memory of the type including a motor element of electrostrictive material, a memory element of ferroelectric ceramic material mounted to be stressed by said motor element, the improvement comprising a damping electrode disposed between said motor and memory elements, said electrode comprising an electrically conductive alloy exhibiting significant specific damping capacity.
Claim 6
Dependent Claim
22 words
A ceramic memory element as defined in claim 3 wherein said alloy exhibits a specific damping capacity of at least 20 percent.
Claim 7
Dependent Claim
33 words
A ceramic memory element as defined in claim 4 wherein a portion of said memory element exhibits an electrostrictive effect and performs a motor function enhancing the stress produced by said motor element.
Claim 8
Dependent Claim
157 words
A nondestructive ceramic memory comprising: a. a thin, rectangular sheet of electrostrictive material, b. a first thin film electrode disposed atop said electrostrictive sheet, c. a second thin film electrode disposed beneath said electrostrictive sheet, d. a thin sheet of ceramic material mechanically mounted atop said first electrode and adapted to be stressed by said electrostrictive sheet upon application of an electric field between said first and second film electrodes, e. a plurality of thin film bit electrodes disposed atop said ceramic sheet only in the regions maximally stressed by said electrostrictive sheet, f. the ceramic material beneath each bit electrode being polarizable to one of two ferroelectric domain orientations in response to an electric field of sufficient magnitude applied via that bit electrode, stress of said ceramic sheet producing a voltage at each bit electrode having a polarity indicative of the stored domain orientation beneath that electrode, and g. means for mechanically damping said ceramic sheet.
Claim 9
Dependent Claim
157 words
A nondestructive ceramic memory comprising: a. a thin, rectangular sheet of electrostrictive material, b. a first thin film electrode disposed atop said electrostrictive sheet, c. a second thin film electrode disposed beneath said electrostrictive sheet, d. a thin sheet of ceramic material mechanically mounted atop said first electrode and adapted to be stressed by said electrostrictive sheet upon application of an electric field between said first and second film electrodes, e. a plurality of thin film bit electrodes disposed atop said ceramic sheet only in the regions maximally stressed by said electrostrictive sheet, f. the ceramic material beneath each bit electrode being polarizable to one of two ferroelectric domain orientations in response to an electric field of sufficient magnitude applied via that bit electrode, stress of said ceramic sheet producing a voltage at each bit electrode having a polarity indicative of the stored domain orientation beneath that electrode, and g. means for mechanically damping said ceramic sheet.
Claim 10
Dependent Claim
28 words
A ceramic memory according to claim 6 wherein said means for mechanically damping comprises an energy absorbing synthetic rubber used to mount said ceramic memory to a substrate.
Claim 11
Dependent Claim
29 words
A ceramic memory according to claim 6 wherein said means for mechanically damping comprises an epoxy resin bead attaching one edge of said ceramic memory to a rigid substrate.
Claim 12
Dependent Claim
27 words
A ceramic memory according to claim 6 wherein said means for mechanically damping comprises a clamp attaching one edge of said ceramic memory to a rigid substrate.
Claim 13
Dependent Claim
23 words
A ceramic memory according to claim 6 wherein said means for mechanically damping comprises a mechanical damping alloy utilized as said second electrode.
Claim 14
Dependent Claim
47 words
A ceramic memory according to claim 6 wherein said electrostrictive and ceramic sheets are generally rectangular, said bit electrodes being disposed in a row along the centerline of said ceramic sheet, each bit electrode having a width less than about one-half the width of said electrostrictive sheet.
Claim 15
Dependent Claim
92 words
A ceramic memory according to claim 11 wherein the width of said ceramic sheet is substantially equal to the width of said electrostrictive sheet, and further comprising a generally U-shaped electrode disposed atop said ceramic sheet between said bit electrodes and the longitudinal edges of said ceramic sheet, the portion of ceramic sheet beneath said U-shaped electrode exhibiting an electrostrictive effect so tHat application of an electric field between said U-shaped electrode and said first film electrode will cause said portion to deform and enhance the stress produced by said electrostrictive sheet.
Claim 16
Dependent Claim
116 words
A ceramic memory comprising: a. a first thin sheet of electrostrictive ceramic material, said first sheet electrostrictively functioning as a motor element, b. a second thin sheet of ceramic material mechanically bonded to said first sheet, a portion of said second sheet exhibiting a ferroelectric effect and functioning as a memory element, c. a first planar electrode sandwiched between said first and second sheets, and a second planar electrode disposed on the bottom surface of said motor element, and d. one or more signal bit electrodes disposed atop said memory element adjacent the center thereof, the maximum dimension of each bit electrode being no greater than about one-half the maximum width dimension of said motor element.
Claim 17
Dependent Claim
116 words
A ceramic memory comprising: a. a first thin sheet of electrostrictive ceramic material, said first sheet electrostrictively functioning as a motor element, b. a second thin sheet of ceramic material mechanically bonded to said first sheet, a portion of said second sheet exhibiting a ferroelectric effect and functioning as a memory element, c. a first planar electrode sandwiched between said first and second sheets, and a second planar electrode disposed on the bottom surface of said motor element, and d. one or more signal bit electrodes disposed atop said memory element adjacent the center thereof, the maximum dimension of each bit electrode being no greater than about one-half the maximum width dimension of said motor element.
Claim 18
Dependent Claim
28 words
A ceramic memory according to claim 13 wherein said first and second sheets both are either generally disc shaped or rectangular and both are of approximately equal size.
Claim 19
Dependent Claim
72 words
A ceramic memory according to claim 13 wherein said first and second sheets are generally rectangular, the length of said first sheet being at least twice the width of said first sheet, said second sheet having a width less than about one-half the width of said first sheet and being disposed along the centerline of said motor element, a plurality of bit electrodes being disposed in a row atop said second sheet.
Claim 20
Dependent Claim
45 words
A ceramic memory according to claim 13 wherein said first and second sheets are circular and wherein said memory element is disposed atop the center of said motor element and has an area less than about 50 percent of the area of said motor element.
Claim 21
Dependent Claim
35 words
A credit, identification or security key card comprising: a generally planar electrically insulative housing, a ceramic memory according to claim 13 incorporated within said housing, and conductor means for making electrical connections to said memory.
Claim 22
Dependent Claim
49 words
A ceramic memory according to claim 13 further comprising interrogate signal means for applying an interrogate voltage across said first and second planar electrodes, the resultant deformation produced within said motor element being transmitted to cause maximum stress of said memory element in the regions beneath said bit electrodes.
Claim 23
Dependent Claim
89 words
A ceramic memory according to claim 18 wherein the regions of said second sheet between said bit electrodes and the outer edge or edges of said second sheet exhibit an electrostrictive effect, and further comprising another electrode disposed atop said electrostrictive regions of said second sheet, said interrogate voltage also being applied between said other electrode and said first planar electrode, the resultant deformation produced in said electrostrictive regions of said second sheet being transmitted to said memory element to enhance the stress produced therein by said motor element.
Claim 24
Dependent Claim
44 words
A ceramic memory according to claim 18 further comprising a second electrostrictive motor element disposed beneath said second planar electrode, a third planar electrode beneath said second motor element, and wherein said interrogate voltage also is applied between said second and third planar electrodes.
Claim 25
Dependent Claim
30 words
A ceramic memory according to claim 18 and transistor circuit means for receiving the unamplified output signal produced at said bit electrode in response to application of said interrogate voltage.
Claim 26
Dependent Claim
16 words
A ceramic memory according to claim 13 further comprising means for mechanically damping said memory element.
Claim 27
Dependent Claim
23 words
A ceramic memory according to claim 22 wherein said means for damping comprises an energy absorbing synthetic rubber mounting for said ceramic memory.
Claim 28
Dependent Claim
26 words
A ceramic memory according to claim 22 wherein said means for damping comprises means for clamping an edge of said ceramic memory to a rigid substrate.
Claim 29
Dependent Claim
20 words
A ceramic memory accoRding to claim 22 wherein said means for damping comprises a Hidamet used as said first electrode.
Claim 30
Dependent Claim
17 words
A ceramic memory according to claim 25 wherein said Hidamet comprises an alloy of nickel and titanium.
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) | 1976-05-14 | 1976-11-13 | 1977-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-14 | 1980-11-13 | 1981-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-14 | 1984-11-13 | 1985-05-15 | $7700.00 | Window Closed / Lapsed |