Sensor array for unauthorized user prevention device

• US 6,817,130 B2
• Filed: 06/16/2003
• Issued: 11/16/2004
• Est. Priority Date: 06/17/2002
• Status: Expired due to Fees

• Current Assignee: New Jersey Institute of Technology
• Original Assignee: New Jersey Institute of Technology
• Inventors: Ivanov, Dentcho
• Primary Examiner(s): JOHNSON, STEPHEN
• Application Number:
  US10/462,384
• Publication Number:
  US 20040031180A1
• Time in Patent Office: 519 Days
• Field of Search: 42/700.1, 42/701.1, 42/700.8, 42/700.6, 42/700.5, 42/66, 382/121, 382/124
• US Class Current: 42/70.06
• CPC Class Codes: F41A 17/066 having means for recognizing biometric parameters, e.g. voice control, finger print or palm print control
• CPC Class Codes: F41A 17/20 Grip or stock safeties, i.e. safeties disengaged by clasping the grip or stock thumb-operated sliding safeties F41A17/52, F41A17/62, F41A17/70, F41A17/80

Abstract

Improvements in the sensor array are disclosed for an array used in a module for preventing unauthorized use of a firearm or other device. The module to which the invention is applicable of the type including a plurality of pressure sensors for sensing a user'"'"'s handgrip on the device; comparator means for comparing a pressure signature profile compiled from an output from said pressure sensors with at least one pressure signature profile in storage; and means for preventing operation of the device when the compared profiles do not match. The improved sensor array comprises a first set of spaced electrically conductive lines formed on the gripping surface; a thin layer of (preferably) piezoresistive material overlying the first set of conductive lines; and a second set of spaced electrically conductive lines formed over the piezoresistive layer. The lines of the second set are orthogonal to the lines of the first set, to establish a grid-like pattern of conductive lines sandwiching the piezoresistive layer. The projected intersections between the lines of the first and second sets (i.e., the grid crossing points) thereby define with the intervening portion of the piezoresistive layer, an array of sensors which are responsive to pressure applied against the gripping surface by a user of the device. Such pressure changes the electrical conductivity in the path including the intersecting lines and intervening piezoresistive material. Signal outputs from the electrical paths including the array of sensors serve to define the pressure signal profile.

Claims

1. In an unauthorized user prevention system for preventing unauthorized users from operating a particular device, said system comprising:

an interlocking means for deactivating the particular device;

a plurality of pressure sensors disposed at a gripping surface of the device for sensing a user'"'"'s handgrip on the device;

comparator means for comparing a pressure signature profile compiled from an output from said pressure sensors with at least one pressure signature profile in storage;

control unit/cpu means for receiving an output from said comparator means indicating that the signature profile compiled by said comparator means matches said at least one pressure signature profile in storage; and

wherein said control unit/cpu means releases said interlocking means upon receipt of a signal from said comparator means that the pressure signature profile of the user'"'"'s handgrip on the particular device matches said at least one pressure signature profile in storage;

The improvement, wherein said sensors comprise;

two orthogonal sets of conductive lines and an intervening piezoresistive or piezoelectric layer being deposited upon said gripping surface, whereby the electrical path between a line of said first set and a line of said second set passes through the intervening piezoresistive or piezoelectric material where the two orthogonal lines cross to define at the crossing a sensor responsive to pressure applied against the gripping surface overlaying the crossing by changing the electrical conductivity or potential in the path including the two said crossing lines and intervening piezoresistive or piezoelectric material;

the multiple crossings of said two orthoganal sets of lines defining an array of said sensors; and

the signal outputs from the electrical paths including said sensors serving to define said pressure signature profile for a user of said device.

2. The invention of claim 1, further including a passivation layer overlying the sets of conductive lines and intervening piezoresistive or piezoelectric layer.

3. The invention of claim 2, wherein said passivation layer comprises silicon nitrite or silicon carbide.

4. In a module for preventing unauthorized use of a fire arm or other device, said module including a plurality of pressure sensors for sensing a user'"'"'s handgrip on the device;

comparator means for comparing a pressure signature profile compiled from an output from said pressure sensors with at least one pressure signature profile in storage; and

means for preventing operation of said device where the compared profiles do not match;

The improvement wherein said sensors comprise;

a first set of spaced electrically conductive lines formed on said gripping surface;

a thin layer of piezoresistive material formed in overlying relation to said first set of lines;

a second set of spaced conductive lines formed over said piezoresistive layer, the lines of said second set being orthogonal to the lines of said first set;

the projected intersections between the lines of said first and second sets defining with the intervening portion of said piezoresistive layer, sensors which are responsive to pressure applied against the gripping surface by a user of the device by said pressure changing the electrical conductivity in the path including the intersecting lines and intervening piezoresistive material;

the signal outputs from the electrical paths including said sensors serving to define said pressure signal profile.

5. The invention of claim 4, further including a passivation layer overlying the sets of conductive lines and intervening piezoresistive layer.

6. The invention of claim 5, wherein said passivation layer comprises silicon nitride or silicon carbide.

7. The invention of claim 4, wherein said device is a firearm.

8. The invention of claim 4, wherein the gripping surface is curved.

9. In an unauthorized user prevention system for preventing unauthorized users from operating a particular device, said system comprising:

an interlocking means for deactivating the particular device;

a plurality of pressure sensors disposed at a gripping surface of the device for sensing a user'"'"'s handgrip on the device;

comparator means for comparing a pressure signature profile compiled from an output from said pressure sensors with at least one pressure signature profile in storage;

control unit/cpu means for receiving an output from said comparator means indicating that the signature profile compiled by said comparator means matches said at least one pressure signature profile in storage; and

wherein said control unit/cpu means releases said interlocking means upon receipt of a signal from said comparator means that the pressure signature profile of the user'"'"'s handgrip on the particular device matches said at least one pressure signature profile in storage;

an improved method for forming the said pressure sensors, comprising;

depositing two orthogonal sets of conductive lines and an intervening piezoresistive or piezoelectric layer being upon said gripping surface, whereby the electrical path between a line of said first set and a line of said second set passes through the intervening piezoresistive or piezoelectric material where the two orthogonal lines cross to define at the crossing a sensor responsive to pressure applied against the gripping surface overlaying the crossing by changing the electrical conductivity or potential in the path including the two said crossing lines and intervening piezoresistive or piezoelectric material;

the multiple crossings of said two orthoganal sets of lines defining an array of said sensors; and

the signal outputs from the electrical paths including said sensors serving to define said pressure signature profile for a user of said device.

10. The method of claim 9, wherein the deposited intervening layer is piezoresistive.

11. The method of claim 9, wherein the outermost set of conductive lines is overcoated with a passivating layer.

12. The method of claim 11, wherein the passivating layer is silicon carbide or silicon nitride.