Optical reader station
View Patent ↗The invention is directed to an optical reader station for reading an object and a method of controlling an illumination source in the station for illuminating the object. The optical reader station comprises a mount for an optical reader and a stand with a surface for receiving the object; the optical reader includes an imager with an object field of view in which the object to be read is positioned. The station further includes a radiation source positioned within the object field of view and arranged to be obstructed by the object when the object is in position to be read. A detection mechanism, which is positioned to receive radiation from the radiation source when the radiation source is not obstructed by the object, deactivates the illumination source when radiation source radiation is detected. The detector mechanism may form part of an auto-exposure control in the imager, which senses ambient light impinging on the imager including the radiation from the radiation source for controlling the illumination level of the illumination source, or it may be a separate detector, which senses the radiation from the radiation source for deactivating the illumination source. The radiation source, which may be an infrared source, a visible light source, a UV source or a luminescence emitter activated by a UV source, may be mounted within the surface of the stand.
1. An optical reader station for reading an object comprising:
an optical reader having:
an imager having an object field of view in which an object is to be positioned to be read; and,
a source of illumination for illuminating the object to be read, wherein the intensity of illumination is controlled by the imager in proportion to the level of ambient light on the object;
a radiation source positioned within the object field of view and being obstructed by the object when the object is positioned to be read; and,
a detector positioned to receive radiation from the radiation source when the radiation source is not obstructed for deactivating the illumination source when radiation is detected.
2. An optical reader station as claimed in claim 1 wherein the radiation source comprises an infrared source.
3. An optical reader station as claimed in claim 1 wherein the radiation source comprises a visible light source.
4. An optical reader station as claimed in claim 1 wherein the radiation source comprises a UV source.
5. An optical reader station as claimed in claim 1 wherein the radiation source comprises a luminescence emitters activated by a UV source.
6. An optical reader station as claimed in claim 1 wherein the detector comprises an auto-exposure control coupled to the imager for detecting the radiation and coupled to the illumination source for controlling the deactivation of the illumination source.
7. An optical reader station as claimed in claim 6 wherein the illumination source is a target source.
8. An optical reader station as claimed in claim 6 wherein the radiation source comprises an infrared source.
9. An optical reader station as claimed in claim 6 wherein the radiation source comprises a visible light source.
10. An optical reader station as claimed in claim 6 wherein the radiation source comprises a UV source.
11. An optical reader station as claimed in claim 6 wherein the radiation source comprises a luminescence emitter activated by a UV source.
12. In an optical reader for reading an object having an imager and an illumination source for illuminating the object to be read, a method for controlling the illumination source comprising:
detecting ambient light impinging on the imager;
controlling the intensity of the illumination source in proportion to the level of ambient light detected by the imager when the object is in a position to be read; and
directing from a radiation source constant radiation having a predetermined threshold level at the imager to determine whether the object is not in a position to be read.
13. A method as claimed in claim 12 wherein the radiation is selected from infrared, visible, UV and luminescent radiation.
14. In an optical reader for reading an object, said reader having an imager and an illumination source for illuminating the object to be read, a method for controlling the illumination source, said method comprising:
detecting ambient light impinging on the imager;
controlling the intensity of the illumination source in proportion to the level of ambient light detected by the imager when the object is in a position to be read;
directing radiation from a radiation source to a detector to determine whether the object is not in a position to be read; and
disabling the illumination source in response to the radiation detected by the detector.
15. A method as claimed in claim 14 wherein the radiation is selected from infrared, visible, UV and luminescent radiation.
16. An optical reader station for reading an object comprising:
an optical reader having:
an imager having an object field of view in which an object is to be positioned to be read; and,
a first source for illuminating the object to be read, the intensity of illumination being controlled by the imager in proportion to the level of ambient light on the object;
a second source positioned within the object field of view and being activated by a radiation from a third source; and,
a detector positioned to receive radiation from the second source when the radiation from the second source is not obstructed by the object for deactivating the first source when the radiation from the second source is detected.
17. An optical reader station as claimed in claim 16 wherein the third source is positioned such that the radiation from the third source to the second source is obstructed by the object when the object is positioned to be read.
18. An optical reader station as claimed in claim 16 wherein the second source comprises a luminescence emitter or a phosphorescent emitter.
19. An optical reader station as claimed in claim 16 wherein the third source comprises a UV source.
20. An optical reader station as claimed in claim 16 wherein the intensity of illumination is controlled by an auto-exposure control.
21. An optical reader station for reading an object comprising:
an optical reader having:
an imager having an object field of view in which an object is to be positioned to be read; and
a source for illuminating the object to be read, the intensity of illumination being controlled by the imager in proportion to the level of ambient light on the object;
a radiation source positioned within the object field of view to be obstructed by the object when the object is positioned to be read;
a detector positioned to receive radiation from the radiation source when the radiation from the radiation source is not obstructed, and
an auto-exposure control for controlling the deactivation of the illumination source when the radiation is detected by the detector.
22. An optical reader station as claimed in claim 21 wherein the illumination source is a target source.
23. An optical reader station as claimed in claim 21 wherein the radiation source comprises an infrared source.
24. An optical reader station as claimed in claim 21 wherein the radiation source comprises a visible light source.
25. An optical reader station as claimed in claim 21 wherein the radiation source comprises a UV source.
26. An optical reader station as claimed in claim 21 wherein the radiation source comprises a luminescence emitter activated by a UV source.