Currency acceptor, and light source for use therein

• US 20030117796A1
• Filed: 12/11/2002
• Published: 06/26/2003
• Est. Priority Date: 12/20/2001
• Status: Active Grant

• Current Assignee: Crane Payment Innovations, Inc. (Crane Company)
• Original Assignee: Mei Incorporated (Crane Company)
• Inventors: Voser, Christian
• Granted Patent: US 6,991,347 B2
• Time in Patent Office: Days
• US Class Current: 362/231
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G06V 10/145 Illumination specially adapted for pattern recognition, e.g. using gratings
• CPC Class Codes: G07D 7/1205 Testing spectral properties
• CPC Class Codes: G07D 7/121 Apparatus characterised by sensor details

Abstract

A multi-wavelength light source for use in a banknote validator comprises a housing containing a plurality of LEDs and a window for releasing light emitted by the LEDs. Visible wavelengths have a direct path to a diffuser located in the window. Infra-red wavelengths have to be diffusively reflected by the interior of the housing before they reach the diffuser, and thereby suffer greater attenuation that the visible wavelengths. The diffuser acts as a substantially point-like light source.

Claims

1. A multi-wavelength light source for illuminating a currency article in a currency validator, the source comprising a housing containing a plurality of LEDs and having a window for releasing light emitted by the LEDs, wherein the light paths from the LEDs to the window differ such that light from at least one LED is attenuated to a greater extent than light from at least one other LED of a different wavelength.

2. A light source as claimed in claim 1, wherein light from said at least one LED can reach the window by diffuse reflection by an inner surface of the housing.

3. A light source as claimed in claim 1 or claim 2, wherein said at least one LED emits infra-red light, and said at least one other LED emits light of a visible wavelength.

4. A light source as claimed in any preceding claim, including a diffuser arranged to diffuse light released by the window.

8. A light source as claimed in any one of claims 4 to 7, wherein at least one of the LEDs is arranged to directly illuminate the diffuser.

9. A light source as claimed in claim 8, wherein said one LED emits light of a visible wavelength.

10. A light source as claimed in any preceding claim, including a collimating lens for producing a collimated light beam from the source.

11. A currency acceptor having a light source as claimed in any preceding claim.

5. A light source for illuminating a currency article in a currency validator, the source comprising a plurality of LEDs and a diffuser receiving light emitted by the LEDs and forming a substantially point-like secondary light source.

6. A light source as claimed in claim 5, wherein the LEDs emit light of different wavelengths.

7. A light source as claimed in claim 5 or 6, wherein the light paths from the LEDs to the diffuser differ such that light from at least one LED is attenuated to a greater extent than light from at least one other LED of a different wavelength.