OPTICAL SYMBOL RECOGNITION SYSTEM

• US 3,636,512 A
• Filed: 02/04/1970
• Issued: 01/18/1972
• Est. Priority Date: 02/04/1970
• Status: Expired due to Term

• Current Assignee: Louis J. Edwards
• Original Assignee: Louis J. Edwards
• Inventors: Edwards, Louis J.
• Primary Examiner(s): Robinson, Thomas A.
• Assistant Examiner(s): Kilgore, Robert M.
• Application Number:
  US05/008,499
• Time in Patent Office: 713 Days
• Field of Search: 235/61.11E 250/219CR 356/71 350/16P,162SF 340/146.3P,146.3F
• US Class Current: 382/210
• CPC Class Codes: G02B 27/46 Systems using spatial filters
• CPC Class Codes: G06V 10/88 Image or video recognition using optical means, e.g. reference filters, holographic masks, frequency domain filters or spatial domain filters

Abstract

An automatic reading apparatus composed of three main parts is provided. The first performs image formation on photochromic material, the second performs image recognition by way of optical spatial filtering and the third part of the system converts the recognized image into useable readout.

Claims

1. Apparatus for recognizing a specific pattern or an object comprising:

a. first light means for projecting a beam of light having a first wavelength onto the specific pattern, b. a first imaging lens for focusing reflected light from the specific pattern onto a photochromic image plate sensitive to light of said first wavelength, c. second light means for projecting a collimated beam of light of a second different wavelength onto and through said photochromic image plate, d. a transform lens for causing the collimated light passing directly through the photochromic image plate to focus on a code filter plate and causing the diffracted light to impinge at various points on said code filter plate to give a diffraction pattern characteristic of the specific pattern, and e. a second imaging lens for causing light passing through the code filter plate to indicate the identity of the specific pattern on a recognition source.

2. The apparatus of claim 1 wherein the first source of light is light of short wavelength.

3. The apparatus of claim 2 wherein the light of short wavelength is ultraviolet.

4. The apparatus of claim 1 wherein the second source of light is light of long wavelength.

5. The apparatus of claim 4 wherein the light of long wavelength is laser lIght.

6. The apparatus of claim 1 wherein the photochromic image plate comprises photochromic film or glass.

7. Pattern recognition apparatus comprising:

a. first light means for projecting a beam of light having a first wavelength onto a specific pattern, b. photochromic image means sensitive to light of said first wavelength, c. means for focusing light reflected from said pattern onto said photochromic image means, d. second light means for projecting a collimated beam of light having a second wavelength through said photochromic image means, and e. means responsive to the diffracted light of said second light means passing through said photochromic image means for determining the identity of said specific pattern.