Integrating light mixer

• US 6,222,623 B1
• Filed: 09/03/1999
• Issued: 04/24/2001
• Est. Priority Date: 09/03/1999
• Status: Expired due to Term

• Current Assignee: Crane Payment Innovations, Inc. (Crane Company)
• Original Assignee: Mars Incorporated
• Inventors: Wetherell, William B.
• Primary Examiner(s): Font, Frank G.
• Assistant Examiner(s): LAUCHMAN, LAYLA G
• Application Number:
  US09/390,125
• Time in Patent Office: 599 Days
• Field of Search: 356/236, 250/228
• US Class Current: 356/236
• CPC Class Codes: G02B 27/123 The splitting element being a lens or a system of lenses, including arrays and surfaces with refractive power
• CPC Class Codes: G07D 7/121 Apparatus characterised by sensor details

Abstract

A document validation subassembly is described. The subassembly includes a light mixer for generating at least one substantially homogenous light spot. The light mixer includes a light mixing chamber, at least one input port for accommodating at least one light source, at least one output, and at least one collimator connected to the output. In an implementation, the light mixing chamber is substantially spherical, but other shapes, such as cylindrical chambers, are also contemplated. Also described are solid core light mixer implementations.

Claims

1. A document validation subsystem, comprising:

a light mixer for generating at least one substantially homogenous light spot, the light mixer comprising

a light mixing chamber,

at least one input port associated with the mixing chamber to accommodate at least one light source,

at least one output associated with the mixing chamber, and

at least one collimator including at least one reflecting surface, the collimator connected to the output; and

at least one light receiver.

2. The apparatus of claim 1, wherein the light mixing chamber includes a diffuse reflective liner applied to an interior surface.

3. The apparatus of claim 1, wherein the reflecting surface is a mirror.

4. The apparatus of claim 1, wherein the input port houses a plurality of LED light sources.

5. The apparatus of claim 4, wherein at least two light sources are of different wavelengths.

6. The apparatus of claim 4, wherein the light sources are of the same wavelength.

7. The apparatus of claim 4, wherein the LED light sources are operable to turn ON sequentially.

8. The apparatus of claim 4, wherein the LED light sources are operable to turn ON simultaneously.

9. The apparatus of claim 1, wherein a plurality of output apertures are associated with the mixing chamber, and a plurality of collimators are connected to the output apertures to generate a plurality of substantially homogenous light spots.

10. The apparatus of claim 1, wherein at least one collimator includes at least one lens.

11. The apparatus of claim 1, further comprising at least one lens component attached to an upper platen of a document passageway.

12. A method for constructing a document validation subsystem, comprising:

constructing a light mixer for generating at least one substantially homogenous light spot;

connecting a light source to the light mixer;

connecting the light mixer and source to a wall of a document passageway; and

connecting a light receiver to a wall of the document passageway to receive a light signal resulting from the substantially homogenous spot.

13. The method of claim 12, wherein the light mixer is constructed by:

molding a chamber having at least one input port and at least one output aperture;

applying a diffuse reflecting coating to an interior surface of the chamber; and

connecting at least one collimator to at least one output aperture.

14. The method of claim 13, wherein the chamber is cast in two hemispheres.

15. The method of claim 13, further comprising attaching a mirror to at least one collimator for directing light.

16. The method of claim 13, further comprising attaching a lens to at least one collimator.

17. The method of claim 12, wherein the light mixer is constructed by:

molding a light mixing chamber using an optical plastics material, wherein the chamber includes at least one input port and at least one output aperture; and

connecting at least one collimator to at least one output aperture.

18. The method of claim 17, further comprising attaching a lens to the collimator.

19. A modular light mixer assembly for use with a document validator, comprising:

a plurality of light mixers, each having at least one input port, at least one output aperture and at least one collimator connected to an aperture, the light mixers arranged to provide light spot output coverage across the width of a document passageway;

a plurality of light sources, wherein at least one light source is connected to each input port; and

at least one light receiver for sensing the light generated by the light spots and for generating document validation signals.

20. A light mixer assembly for use with a document validator, comprising:

a plurality of light mixers, each having at least one input port, at least one output aperture and at least one collimator connected to an aperture, the light mixers arranged to provide light spot output coverage across the width of a document passageway;

a plurality of light sources, wherein at least one light source is connected to each input port; and

at least one light receiver for sensing the light spots and for generating document validation signals.

21. A document validator subassembly, comprising:

a cylinder having a cavity and at least one input port and a slit output, wherein a reflective and diffusive coating is applied to the cavity and at least one collimator having a reflection surface is aligned with the slit output;

at least one light source connected to the input port; and

at least one light receiver.

22. A document validator subassembly, comprising:

a cylinder having a cavity and at least one input port and a plurality of output apertures for generating a plurality of substantially homogenous light spots, wherein a reflective and diffusive coating is applied to the cavity, and a plurality of collimators is attached to the output apertures;

at least one light source connected to the input port; and

at least one light receiver.

23. The subassembly of claim 22, further comprising at least one light pipe connected at a first end to an output aperture and at a second end to a collimator.

24. A document validator subassembly, comprising:

a block of optical material having a cavity that includes an internally reflecting and diffuse surface, at least one input port and at least one output aperture;

at least one collimator having at least one reflecting surface, the collimator attached to the output aperture for generating at least one substantially homogenous output spot;

at least one light source connected to the input port; and

at least one receiver.

25. A method for constructing a document validator subassembly, comprising:

connecting a light mixer to a wall of a document passageway, the light mixer capable of generating at least one substantially homogenous light spot, the light mixer formed by;

cutting a cavity into a block of optical material, the cavity having reflective and diffuse characteristics;

forming at least one input port and at least one output aperture that connect to the cavity;

connecting at least one light source to each input port; and

connecting at least one collimator to an output aperture; and

connecting at least one light receiver to a wall of the document passageway to receive light resulting from the substantially homogenous light spot.

26. A document validator subassembly, comprising:

a light mixer for generating at least one substantially homogenous light spot, the light mixer including a solid core light mixing chamber having an outside coating with diffuse and reflective characteristics, wherein the coating includes at least one input area for accommodating at least one light source, and the coating includes at least one output area, and at least one light directing means including a reflection surface for feeding light energy back into the mixing chamber, the directing means connected to the output area; and

a light receiver.

27. The apparatus of claim 26, wherein the light directing means includes an output area for directing light.

28. The apparatus of claim 27, wherein the light directing means is substantially hemispherically shaped.

29. The apparatus of claim 26, further comprising at least one light source means connected to the input area.

30. The apparatus of claim 26, further comprising a flat mirror for redirecting light from the light direction means.

31. The apparatus of claim 26, further comprising a collimating lens connected to a platen of a document passageway.

32. The apparatus of claim 26, wherein the light mixing chamber is spherical.

33. The apparatus of claim 26, wherein the light mixing chamber is cylindrical.

34. The apparatus of claim 33, further comprising a linear array light source connected to the mixing chamber.

35. A method for constructing a document validator subassembly for generating at least one substantially homogenous light spot, comprising:

forming a solid core light mixer by forming a light mixing chamber of optical material, coating the chamber with a material having reflective and diffuse characteristics, forming at least one input area and at least one output area, and connecting a light directing means to each output area that directs light energy within a collecting angle to a document passageway, and reflects light energy outside the collecting angle back into the mixing chamber;

connecting the solid core light mixer to a wall of a document passageway; and

connecting a light receiver to a wall of the document passageway.

36. The method of claim 35, further comprising applying an external protective layer to the coating material.

37. The method of claim 35, further comprising connecting at least one light source to each input area.

38. The method of claim 35, wherein the light directing means directs light within a collecting angle to a document passageway, and reflects light energy outside the collecting angle back into the mixing chamber.

39. The method of claim 35, wherein the light mixing chamber is formed in a spherical shape.

40. The method of claim 35, wherein the light mixing chamber is formed in a cylindrical shape.