Method of reading electrical information and information carrying member for use in the method

• US 5,453,602 A
• Filed: 08/31/1992
• Issued: 09/26/1995
• Est. Priority Date: 09/01/1989
• Status: Expired due to Fees

• Current Assignee: TOYO Ink Manufacturing Company Limited
• Original Assignee: TOYO Ink Manufacturing Company Limited
• Inventors: Hanada, Koji
• Primary Examiner(s): Hajec, Donald
• Assistant Examiner(s): Frech, Karl D.
• Application Number:
  US07/937,451
• Time in Patent Office: 1,121 Days
• Field of Search: 235/439, 235/435, 235/444, 235/449, 235/451, 235/492, 235/493, 369/126
• US Class Current: 235/439
• CPC Class Codes: G06K 7/081 electrostatic, e.g. by detecting the charge of capacitance between electrodes

Abstract

A method of reading electrical information, which comprises arranging electric field-generating means having a pulse oscillator and detection means of detecting a potential in the electric field to form an electrostatic coupling space and/or a latent electrostatic coupling space where the and the detection means can sense a change in the electric field as a change of potential passing an information carrying member formed by covering an electrically conductive member having a form expressing information with an electrically nonconductive material through the electrostatic coupling space or the latent electrostatic coupling space, thereby to detect the information expressed by the form of the electrically conductive member, and information carrying member for use in the method.

Claims

1. A method of detecting an electrically conductive pattern contained in an information carrying member, the conductive pattern representative of predetermined information and being covered by an electrically non-conductive material, said method comprising the steps of:

forming an electrostatic coupling space by applying a voltage to an electric field generating device to generate an electric field extending from the electric field generating device to an electric field detecting device;

passing the information carrying member through said electrostatic coupling space;

electrostatically grounding the conductive pattern of the information carrying member while the information carrying member is passed through said electrostatic coupling space;

detecting a change in the electric field from an ON state of an OFF state, using said electric field detecting device, while the information carrying member is passed through said electrostatic coupling space; and

,

discriminating a presence of said conductive pattern within said electrostatic coupling space in response to a detected change in said electric field from said ON state to said OFF state;

wherein said electric field extending from said electric field generating device to said electric field detecting device becomes said OFF state when said electric field is cut off by an electrostatic screening effect when said conductive pattern is electrostatically grounded and located within said electrostatic coupling space.

2. A method according to claim 1, wherein the information carrying member further includes a common electrically conductive plate member electrically coupled to said conductive pattern.

3. A method according to claim 2, wherein said electrostatically grounding step includes electrostatically coupling said common electrically conductive plate with a grounding plate.

4. A method according to claim 1, wherein said electrostatically grounding step includes positioning said information carrying member in parallel with and contiguous to a grounding plate.

5. A method according to claim 1, further comprising providing a guard plate in association with at least one of said electric field generating device and said electric field detecting device to control formation of said electrostatic coupling space.

6. A method of detecting an electrically conductive pattern contained in an information carrying member, the conductive pattern representative of predetermined information and being covered by an electrically non-conductive material, said method comprising the steps of:

forming a latent electrostatic coupling space by applying a voltage to an electric field generating device to generate an electric field extending from the electric field generating device to an electric field detecting device;

passing the information carrying member through said latent electrostatic coupling space;

electrostatically grounding the conductive pattern of the information carrying member while the information carrying member is passed through said latent electrostatic coupling space;

detecting a change in the electric field, using said electric field detecting device, while the information carrying member is passed through said latent electrostatic coupling space; and

,

discriminating a presence of said conductive pattern within said latent electrostatic coupling space according to a detected change in said electric field;

wherein said electric field extending from said electric field generating device to said electric field detecting device is cut off by an electrostatic screening effect when said conductive pattern is electrostatically grounded and located within said latent electrostatic coupling space;

wherein said electric field generating device and said electric field detecting device are entirely located on a same side of the information carrying member during said passing step;

wherein said electrostatically grounding step includes positioning said information carrying member in parallel with and contiguous to a grounding plate; and

wherein said method further comprises providing a guard plate surrounding said electric field generating device and said electric field detecting device, said guard plate having an edge defining an opening therein, and connecting said grounding plate to said edge of said guard plate such that said grounding plate does not cover said opening, and wherein said passing step includes moving the information carrier relative to said electric field generating device and said electric field detecting device so as to pass the opening of said guard plate along said information carrying member.

7. A method of detecting an electrically conductive pattern contained in an information carrying member, the conductive pattern representative of predetermined information and being covered by an electrically non-conductive material, said method comprising the steps of:

forming a latent electrostatic coupling space by applying a voltage to an electric field generating device to generate an electric field extending from the electric field generating device to an electric field detecting device;

passing the information carrying member through said latent electrostatic coupling space;

electrostatically grounding the conductive pattern of the information carrying member while the information carrying member is passed through said latent electrostatic coupling space;

detecting a change in the electric field, using said electric field detecting device, while the information carrying member is passed through said latent electrostatic coupling space; and

,

discriminating a presence of said conductive pattern within said latent electrostatic coupling space according to a detected change in said electric field;

wherein said electric field extending from said electric field generating device to said electric field detecting device is cut off by an electrostatic screening effect when said conductive pattern is electrostatically grounded and located within said latent electrostatic coupling space;

wherein said electric field generating device and said electric field detecting device are entirely located on a same side of the information carrying member during said passing step;

wherein said electrostatically grounding step includes positioning said information carrying member in parallel with and contiguous to a grounding plate; and

wherein said method further comprises providing said electric field detecting device so as to surround said electric field generating device, and providing said guard plate as first and second guard plates, the first guard plate being provided so as to surround the electric field detecting device, and the second guard plate being provided partially interposed between the electric field detecting device and the electric field generating device.