CARD-CHANGEABLE CAPACITOR READ-ONLY MEMORY

• US 3,593,319 A
• Filed: 12/23/1968
• Issued: 07/13/1971
• Est. Priority Date: 12/23/1968
• Status: Expired due to Term

• Current Assignee: William D. Barber
• Original Assignee: William D. Barber
• Inventors: Barber, William D.
• Application Number:
  US04/786,269
• Time in Patent Office: 932 Days
• US Class Current: 365/102
• CPC Class Codes: G11C 17/04 using capacitive elements G11C17/06, G11C17/14 take precedence

Abstract

A low cost read-only capacitive storage memory is described wherein the word lines and bit lines of the read matrix are formed as a plurality of straight conductors orthogonally disposed on opposite sides of an insulating layer. To encode the read matrix, a printed circuit card having conductive platelets selectively positioned thereon is disposed conductor-side downward atop the matrix with the platelets in registration with selective crossover areas of the word and bit lines and readout is effected by a measurement of the electrical signal capacitively coupled from a driven word line to the bit lines. Preferably the platelets are formed as orthogonal crosses vacuum deposited atop a flexible substrate to permit contouring of the platelets for maximum capacitive coupling between the word and bit lines.

Claims

1. A read-only capacitive memory comprising a. A read matrix characterized by an insulating layer, a first plurality of parallel conductors extending across and completely underlying said insulating layer, a second plurality of parallel conductors extending across and completely overlying said insulating layer, said first conductors being orthogonal to said second conductors to form a matrix having a multiplicity of crossover areas common to said first and second plurality of conductors, said first and second plurality of parallel conductors forming an irregular surface on said insulating layer;

b. A storage medium for encoding the matrix, said storage medium being characterized by areas of a relatively high conductivity material representative of information of a first magnitude and areas of a relatively low conductivity material representative of information of a second magnitude, said storage medium being flexible and conforming in a complementary fashion to the irregular surface of said read matrix for encoding said matrix by being so positioned in close proximity thereto that each information area of said storage medium is registered with the crossover areas of said conductors forming the matrix and extends beyond at least one edge the crossover areas to capacitively couple the first and second conductors common to the crossover area;

c. Means for selectively driving at least one conductor forming the matrix; and

d. Means for detecting the electrical signal capacitively coupled from said driven conductor to an orthogonally disposed conductor.

2. A read-only capacitive memory according to claim 1 wherein said relatively high conductivity areas are shaped as orthogonal crosses, the center of said crosses being registered with the center of selective crossover areas of said conductors forming the matrix.

3. A read-only capacitive memory according to claim 2 wherein the arms of said cross extend beyond the edges of the immediately underlying conductor by a distance at least equal to the span from said storage medium plane to the plane of said plurality of conductors remote from said storage medium.

4. A read-only capacitive memory according to claim 1 wherein said insulating layer is partially etched in areas intermediate one set of parallel conductors to form a contoured surface and said storage medium comprises a flexible dielectric substrate having relatively high conductivity areas selectively formed thereon, said capacitive memory further including means for contouring said flexible substrate to a complementary configuration relative to said insulating layer contoured surface.

5. A read-only capacitive memory according to claim 4 wherein said metallic areas have the general configuration of orthogonal crosses and said contouring means include means for applying forced air upon said flexible substrate face remote from said metallic areas.

6. A read-only capacitive memory according to claim 1 wherein four crossover areas of said orthogonally disposed conductors are employed to form each information storage site of said memory and said relatively high conductivity areas of said storage medium are '"'"''"'"''"'"''"'"'L'"'"''"'"''"'"''"'"' shaped, each arm of said L-shaped area extending beyond the registered crossover areas in a direction toward two other crossover areas forming the storage site.