Integrated solid state light emitting and detecting array and apparatus employing said array

• US 5,319,182 A
• Filed: 03/04/1992
• Issued: 06/07/1994
• Est. Priority Date: 03/04/1992
• Status: Expired due to Fees

• Current Assignee: Welch Allyn Data Collection Inc (Welch Allyn Incorporated)
• Original Assignee: Welch Allyn Incorporated
• Inventors: Havens, William H., Hammond, Charles M. Jr.
• Primary Examiner(s): Hajec, Donald
• Assistant Examiner(s): Chin, Esther
• Application Number:
  US07/846,471
• Time in Patent Office: 825 Days
• Field of Search: 235/472, 235/454, 235/460, 235/462, 235/440, 250/208.2, 250/208.1, 250/552, 250/553, 250/568, 250/566
• US Class Current: 235/462.42
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10831 Arrangement of optical elements, e.g. lenses, mirrors, prisms optical elements per se G02B
• CPC Class Codes: G06K 7/10841 Particularities of the light-sensitive elements semiconductor devices H01L
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 31/173 formed in, or on, a common substrate

Abstract

There is provided an integrated semiconductor source-detector matrix in which solid state photonic diodes are configured as LEDs, disposed on a substrate and coupled to electronic circuits so that the diodes can be individually driven to emit light or to detect light as may be desired. Providing an integrated matrix of light source (emitter) and light sensor units disposed in close proximity results in each unit having nearly coextensive fields of view and illumination. Apparatus, such as bar code and optical readers utilizing such a matrix are shown, and are insensitive to the diffusion and laminate effects. In alternate embodiments the matrix is coupled to remote sensors or another similar matrix to provide optical communication and interchange devices having high bandwidth.

Claims

1. An optical information detecting apparatus comprising:

an integrated, solid state structure further comprising

a plurality of photonic diodes configured as a plurality of light sensors and a plurality of light emitting elements disposed on a substrate and are electrically isolated from one another, said light sensors being optically isolated from said light emitting elements, said diodes having a vertical structure, comprising a plurality of identically fabricated layers, corresponding layers of said diodes being mutually coplanar;

circuit means connected to said light sensors for enabling said diodes to detect light, whereby a signal is generated in response to said detected light; and

means for directing light that emanates from said light emitting elements to a target and for returning light that contains optical information to said light sensors, said means for directing light being external to said solid state structure;

whereby said signal is indicative of an optical characteristic of said target.

2. The apparatus of claim 1, further comprising control means for selectively enabling and disabling said diodes.

3. The apparatus of claim 1 wherein said photonic diodes have identical length and width dimensions.

4. The apparatus of claim 1, further comprising means for processing said signal.

5. The apparatus of claim 1, wherein said diodes are disposed between said substrate and said light directing means.

6. An optical information detecting apparatus comprising

an integrated, solid state structure further comprising

a first plurality of substantially coplanar photonic diodes disposed on a substrate and are optically and electrically isolated from one another;

circuit means for enabling said diodes to detect light, whereby a signal is generated in response to said detected light;

a second plurality of light emitting elements comprising identically fabricated photonic diodes that are substantially coplanar with said first plurality of photonic diodes said first and second plurality of photonic diodes being identically fabricated;

means for switchably operating at least one of said identically fabricated photonic diodes in a photoemissive mode and a photodetecting mode; and

means for directing light that emanates from said light emitting elements to a target and for returning light that contains optical information to said diodes, said means for directing light being external to said solid state structure;

whereby said signal is indicative of an optical characteristic of said target.

7. A bar code reading apparatus having an integrated, solid state structure that comprises

a plurality of photodiodes disposed on a substrate and are electrically isolated from one another, said diodes having a vertical structure, comprising a plurality of layers, corresponding layers of said diodes being mutually coplanar, said diodes further having identical length and width dimensions;

circuit means for enabling said photodiodes to detect light, whereby a signal is generated in response to said detected light,

a plurality of light emitting diodes having a vertical structure, comprising a plurality of layers that are substantially coplanar with corresponding layers of said photodiodes, said photodiodes and said light emitting diodes being identically fabricated and

means for directing light that emanates from said light emitting diodes onto indicia being read and for returning light reflected from said indicia to said photodiodes, said means for directing light being external to said solid state structure.

8. The apparatus of claim 7, further comprising control means for selectively enabling and disabling said light emitting diodes and said photodiodes, whereby a variable area on a target can be scanned.

9. The apparatus of claim 7 wherein said light emitting diodes and said photodiodes have identical length and width dimensions.

10. The apparatus of claim 7, wherein said light emitting elements and said photodiodes comprise identically fabricated photonic diodes.

11. The apparatus of claim 7, further comprising means for processing said signal.

12. The apparatus of claim 11, wherein said means for processing and said integrated solid state structure are integral within a common housing.

13. The apparatus of claim 11, wherein said means for processing and said solid state structure are integrated on a common substrate.

14. The apparatus of claim 7, wherein said photodiodes and said light emitting diodes are operatively associated as members of functional subunits, and light that emanates from light emitting members of a subunit and passes through said light directing means is reflected from said indicia and communicated to light sensing members of said subunit.

15. The apparatus of claim 7, wherein at least two light emitting diodes are connected in non-isolated electrical connection to a common data line, whereby a plurality of light emitting diodes can be simultaneously controlled in a matrix without addressing logic.

16. The apparatus in accordance with claim 7, wherein said photodiodes are optically isolated from said light emitting diodes.

17. The apparatus in accordance with claim 7, wherein said photodiodes are identically fabricated.

18. A method of reading indicia on a substrate, comprising the steps of:

collocating a plurality of identically fabricated light emitting and light sensing elements in a region, said elements having a vertical structure, comprising a plurality of layers, corresponding layers of said elements being mutually coplanar, said elements further having identical length and width dimensions;

forming optical images of said elements on an indicia;

causing a light emitting element to emit light that is incident on said indicia and is reflected therefrom into said region;

detecting reflected light with at least one of said light sensing elements and producing a signal in response thereto that is indicative of an optical characteristic of said indicia.

19. The method of claim 18, wherein said substrate has a diffusion path length, and optical images of said elements are no larger than said diffusion path length.

20. The method of claim 19, wherein said diffusion path length is less than about 0.05 mm.

21. The method of claim 18, further comprising the steps of connecting at least two identical elements selected from said light sensing elements and said light emitting elements in non-isolated electrical connection with a common data.

22. The method according to claim 18, wherein said light emitting elements are optically isolated from said light sensing elements.

23. An optical information detecting apparatus comprising:

an integrated, solid state structure further comprising

a plurality of photodiodes configured as light sensors disposed on a substrate, said photodiodes each having a non-isolated electrical connection to a common control line, whereby a matrix of said photodiodes can be controlled without addressing logic; and

a plurality of light emitting elements that are substantially coplanar with said photodiodes, said photodiodes and said light emitting elements being identically fabricated; and

means for directing light that emanates from said light emitting elements to a target and for returning light that contains optical information to said photodiodes, said means for directing light being external to said solid state structure;

whereby said signal is indicative of an optical characteristic of said target.

24. The apparatus in accordance with claim 23, wherein said photodiodes are optically isolated from said light emitting elements.

25. An optical information detecting apparatus comprising:

an integrated, solid state structure further comprising;

a plurality of photonic diodes configured as a plurality of light sensors that generate a signal responsive to light incident thereon, and a plurality of light emitting diodes disposed on a substrate, said diodes having a vertical structure comprising a plurality of identically fabricated layers, corresponding layers of said diodes being mutually coplanar; and

means for directing light that emanates from said light emitting diodes to a target and for returning light that contains optical information to said light sensors, said means for directing light being external to said solid state structure;

whereby said signal is indicative of an optical characteristic of said target.

26. The apparatus of claim 25 wherein said photonic diodes have identical length and width dimensions.

27. The apparatus in accordance with claim 25, wherein said light sensors are optically isolated from said light emitting diodes.

28. A method of reading indicia on a substrate, comprising the steps of:

collocating a plurality of light emitting and light sensing elements in a region, said light emitting and light sensing elements being identically fabricated;

connecting at least two identical elements selected from said light sensing elements and said light emitting elements in non-isolated electrical connection with a common data line;

forming optical images of said elements on an indicia;

causing a light emitting element to emit light that is incident on said indicia and is reflected therefrom into said region;

detecting reflected light with at least one of said input sensing elements and producing a signal in response thereto that is indicative of an optical characteristic of said indicia.

29. The method according to claim 28, wherein said light emitting elements are optically isolated from said light sensing elements.