CODED TAPE AND OPEN CONTACT SENSING CIRCUIT

• US 3,666,925 A
• Filed: 05/21/1970
• Issued: 05/30/1972
• Est. Priority Date: 05/21/1970
• Status: Expired due to Term

• Current Assignee: Ira R. Marcus
• Original Assignee: Ira R. Marcus
• Inventors: Marcus, Ira R.
• Primary Examiner(s): Robinson, Thomas A.
• Application Number:
  US05/039,402
• Time in Patent Office: 740 Days
• Field of Search: 340/347PR 235/61.111,61.113
• US Class Current: 235/441
• CPC Class Codes: G06K 19/067 Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
• CPC Class Codes: G06K 7/065 for conductive marks
• CPC Class Codes: H03M 1/26 with weighted coding, i.e. the weight given to a digit depends on the position of the digit within the block or code word, e.g. there is a given radix and the weights are powers of this radix

Abstract

A coded tape used to preset a binary counter to any desired predetermined count is composed of two principal parts. The first part comprises an insulating layer or substrate and a conducting layer. The conducting layer is etched or scribed to divide it into a plurality of bit tracks. The second part also comprises two layers and may comprise an insulating layer and a conducting layer which are punched out in the form of the Gray Code pattern. This part is laminated to the first part to form a unitary structure. Alternatively, a conductive layer is bonded to the first part by an adhesive which acts as an insulating layer. The second conductive layer and adhesive are selectively etched to form the Gray Code pattern. One of the conducting layers is biased through a resistance to ground while the other is biased to a different potential. The binary counter is preset by positioning the tape with respect to a read head having a brush for each of the plurality of bit tracks. The code at that point on the tape is transferred from the read head through a code converter to the binary counter. A brush contacting the first conductive layer causes a binary '"'"''"'"''"'"''"'"'zero'"'"''"'"''"'"''"'"' to be read, and a brush contacting the second conductive layer causes a binary '"'"''"'"''"'"''"'"'one'"'"''"'"''"'"''"'"' to be read. The open contact sensing circuit senses when any brush is not in contact with either the first or second conductive layers and prevents the binary counter from being preset.

Claims

1. A coded record for cooperating with a read head having a plurality of brush contacts, comprising:

a. a first insulating layer, b. a first electrically conductive layer bonded to said first insulating layer and divided into a plurality of bit tracks, c. a second insulating layer, and d. a second electrically conductive layer, both said second insulating layer and said second conductive layer being bonded to said first conductive layer and formed into a coded pattern, each layer being non-planar with the other layers to form a laminate structure, said first conductive layer connected to a first potential and said second conductive layer connected to a second potential.

2. a first conductive layer bonded to said first insulating substrate and divided into a plurality of bit tracks, said first conductive layer being connected to a first potential,

3. The combination recited in claim 2 wherein the open brush contact sensor comprises:

a. a multiple input OR circuit connected to said brush contacts, and b. means for sampling the output of said multiple input OR circuit.

4. a second conductive layer, both said second insulating layer and said second conductive layer being bonded to said first conductive layer and formed into a coded pattern, said second conductive layer being connected to a second potential, b. a read head having at least one brush contact for each bit track, the brush contact sensing the occurrence of a first or second potential on an associated track, and c. an open brush contact sensor connected to each of said brush contacts to provide a first output when all of said brush contacts sense either said first or second potential and a second output if any one of said brush contacts senses an open circuit.

5. The combination as recited in claim 4 wherein said means for sampling includes an MOS transistor having its gate electrode connected to the output of said multiple input OR circuit, said MOS transistor having a minimum threshold voltage greater than said voltage range and a maximum threshold voltage less than said greater voltage.