Special pen and system for handwriting recognition

• US 3,906,444 A
• Filed: 10/11/1973
• Issued: 09/16/1975
• Est. Priority Date: 10/11/1973
• Status: Expired due to Term

• Current Assignee: Hewitt David Crane, Robert Ellis Savoie
• Original Assignee: Hewitt David Crane, Robert Ellis Savoie
• Inventors: Crane, Hewitt David, Savoie, Robert Ellis
• Primary Examiner(s): Boudreau, Leo H.
• Application Number:
  US05/405,296
• Time in Patent Office: 705 Days
• Field of Search: 340/146.3AE,146.3SY,146.3SG,146.3R,146.3AC,146.3F 250/202,556,567,578
• US Class Current: 382/122
• CPC Class Codes: B43K 29/08 with measuring, computing or indicating devices
• CPC Class Codes: G06V 40/30 Writer recognition; Reading and verifying signatures
• CPC Class Codes: G07C 9/247 electronically, e.g. by comparing signal of hand-writing with a reference signal from the pass

Abstract

A system enabling automatic identification of a hand written signature is provided. A specimen signature is written with a special pen which will provide as output, signals representing the direction which that pen is moved to produce that signature. This information is converted into direction per unit of time which is stored at a particular address in the memory of a data processing machine. For verification of such a signature, an individual indicates to the machine, in any suitable manner, the address where his signature is stored in memory, and then proceeds to write his signature again with said pen. The direction per unit of time information which is generated at this time, is compared with the direction per unit of time read out of memory. If there is sufficient correlation, the machine indicates the signature is acceptable. If not, it indicates the signature is not acceptable.

Claims

1. A system for verifying a signature, written with a writing instrument, with a previously written signature comprising means, responsive to the direction of motion of said writing instrument while writing said signature to generate direction signals representative thereof, means for generating clock signals, means responsive to said direction signals and said clock signals to produce first clocked direction signals only during the intervals of clock signals, means for establishing second clocked direction signals for said previously written signature, means for normalizing said first clocked direction signals with respect to said second clocked direction signals, means for comparing said normalized first clocked direction signals with said second clocked direction signals of said previously written signature and producing a verification or non-verification output signal, and means responsive to said output signal to indicate verification or non-verification.

2. A system as recited in claim 1 wherein said means responsive to the directions of motion of said writing instrument to generate direction signals representative thereof, includes light emitting means supported within said writing instrument for motion which follows the motion of said writing instrument when writing, and photocell means supported within said writing instrument for generating signals responsive to light from said light emitting means representative of the directions of motion of said light emitting means.

3. A system as recited in claim 1 wherein said means, resPonsive to the direction of motion of said writing instrument while writing said signature, to generate direction signals comprises quadrantial means within said writing instrument for generating first, second, third, and fourth signals respectively representative of motion by said writing instrument in each of four quadrants, means for adding first and second signals to produce a fifth signal, means for adding third and fourth signals to produce a sixth signal, means for adding said first and third signals to produce a seventh signal, means for adding said second and forth signals to produce an eighth signal, means for subtracting said fifth signal from said sixth signal to produce an X direction signal where said X direction signal represents a component of motion in one direction, and means for subtracting said seventh signal from said eighth signal to produce a Y direction signal where said Y direction signal represents a component of motion orthogonal to said component of motion in said one direction.

4. A system as recited in claim 3 wherein said means, responsive to the direction of motion of said writing instrument while writing said signature, to generate direction signals further comprises means for dividing said Y direction signal by said X direction signal to produce a tan theta signal, and means for converting said tan theta signal to a theta signal, where theta represents the angular direction of motion.

5. A system as recited in claim 1 wherein said means for normalizing said first clocked direction signals with respect to said second clocked direction signals includes means for deriving from said first clocked direction signals as many direction signals as there are in said second clocked direction signals.

6. A system for verifying a signature written with a writing instrument with a previously written signature comprising means, responsive to the direction of motion of said writing instrument while writing, for producing X signals, representative of a component of motion in one direction and Y signals representative of a component of motion in a direction orthogonal to said motion in one direction, means for dividing said Y signals by said X signals to provide tan theta signals, where theta is an angular direction signal, means for generating clock signals, means responsive to said clock signals for sampling said tan theta signals over the interval of writing said signature with said writing instrument to produce clocked tan theta signals, means for converting said clocked tan theta signals to first clocked theta signals, means for establishing second clocked theta signals for said previously written signature, means for normalizing said first clocked theta signals with respect to said second clocked theta signals, means for comparing said normalized first clocked theta signals with said second clocked theta signals and producing a verification or non-verification output signal, and means responsive to said output signal to indicate verification or non-verification

7. A system as recited in claim 6 wherein said means responsive to the direction of motion of said writing instrument while writing for producing X and Y signals includes light emitting means supported within said writing instrument for motion which follows the motion of said writing instrument when writing, and photocell means supported within said writing instrument for generating signals responsive to light from said light emitting means representative of the directions of motion of said light emitting means.

8. A system as recited in claim 6 wherein said means for normalizing said first clocked theta signals with respect to said second clocked theta signals includes means for deriving from said normalized first clocked theta signals as many clocked theta signals as there are in said second clocked theta signals.

9. A systEm as recited in claim 6 wherein said means for comparing said normalized first clock signals with said second clocked theta signals and producing a verification or non-verification thereof includes means for subtracting said normalized first clocked theta signals from said second clocked theta signals and producing difference signals, means for squaring said difference signals, means for summing said squared difference signals, to produce summed signals, means for establishing threshold signals, and means for subtracting said summed signals from said threshold signals to produce verification or nonverification signals.

10. The method of verifying a signature written with a writing instrument with a previously written signature comprising generating X signals representative of motion in one direction and Y signals representative of motion in a direction orthogonal to said one direction while said writing instrument is writing said signature, dividing said Y signals by said X signals to provide tan theta signals, sampling said tan theta signals with clock signals over the interval of the writing of said signature to produce clocked tan theta signals, converting said clocked tan theta signals to first clocked theta signals, establishing second clocked theta signals for said previously written signature, normalizing said first clocked theta signals with respect to said second clocked theta signals, and comparing said normalized clocked theta signals with said second clocked theta signals and producing a verification or non-verification output signal in response to said comparison.

11. A system for generating signals representative of the direction of motion taken in writing comprising a housing enclosing an elongated member having writing means on one end and light emitting means on the other end, means for movably supporting said elongated member within said housing to enable said other end on which said light emitting means is mounted to move to a position determined by the direction of motion described by said one end while writing, photocell means responsive to the light emitted by said light emitting means for generating four signals representative of each quadrant of motion described by said one end while writing, and switch means within said housing actuated responsive to writing pressure being applied to said writing means for enabling said light emitting means to become operative to emit light.

12. A system as recited in claim 11 wherein there is further included means for adding a first and second of said four signals for generating a fifth signal, means for adding a second and third of said four signals for generating a sixth signal, means for adding said first and third signals for generating a seventh signal, means for adding said second to said fourth signals for generating an eighth signal, means for subtracting said fifth signal from said sixth signal for producing an X direction signal where said X direction signal represents a component of motion in one direction, and means for subtracting said seventh signal from said eighth signal to produce a Y direction signal where said Y direction signal represents a component of motion orthogonal to said component of motion in said one direction.

13. A system as recited in claim 12 wherein there is included means for dividing said Y direction signal by said X direction signal to produce a tan theta signal, and means to convert said tan theta signal to a theta signal wherein theta represents the angular direction of motion.

14. A system as recited in claim 11 wherein said means for movably supporting said elongated member within said housing comprises a ball and socket joint, and said photocell means comprises four photocell means positioned within said housing for generating a separate signal for each quadrant illuminated by said light eMitting means.