Indicia reading terminal including optical filter

• US 8,640,958 B2
• Filed: 01/21/2010
• Issued: 02/04/2014
• Est. Priority Date: 01/21/2010
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Lu, Reck, Zhu, Xiaoxun
• Primary Examiner(s): Haupt, Kristy A
• Application Number:
  US13/057,236
• Publication Number:
  US 20120298755A1
• Time in Patent Office: 1,475 Days
• Field of Search: 235/462.11, 235/462.24, 235/462.41, 235/462.42, 235/468
• US Class Current: 235/462.11
• CPC Class Codes: G06K 19/0614 the marking being selective to wavelength, e.g. color barcode or barcodes only visible under UV or IR methods or arrangements for sensing record carriers using a selected wavelength, see G06K7/12
• 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 7/12 using a selected wavelength, e.g. to sense red marks and ignore blue marks

Abstract

Embodiments of the present invention comprise an indicia reading terminal that is operatively configured to decode visible and non-visible decodable indicia. The terminal can comprise an excitation illumination module for illuminating the decodable indicia with light that has a wavelength selected so as to permit the decodable indicia to emit light. The terminal can also comprise a filter module with an optical filter that has filter regions configured to pass certain wavelengths of light. The terminal can also comprise an image sensor module with an image sensor located so as to receive light emitted from the decodable indicia from the filter region.

Claims

1. An indicia reading terminal for imaging decodable indicia comprising a printed material visible in response to light in a non-visible spectrum, said terminal comprising:

an illumination source for casting light onto the decodable indicia, the light having a wavelength in the non-visible spectrum, the wavelength causing light emitted from the printing material having an emission wavelength in a visible spectrum;

an optical filter receiving the emitted light, the optical filter comprising a filter region having a pass-band matching the emission wavelength;

an image sensor responsive to the emission wavelength in a manner permitting decoding of the decodable indicia, the image sensor comprising a plurality of pixels including one or more of a first subset of monochrome pixels and a second subset of color pixels; and

a hand held housing in surrounding relation to one or more of the illumination source, the image sensor, and the optical filter,

wherein the image sensor defines an optical axis on which is aligned the filter region of the optical filter, wherein said hand held terminal is operative for manual activation by a trigger depressed by an operator, wherein the trigger causes at least one attempt to decode the decodable indicia, and wherein said handheld terminal is operative to assign one or more of the pass-band of the optical filter and the wavelength of the light generated by the illumination source based the attempt to decode the decodable indicia.

2. An indicia reading terminal according to claim 1, further comprising an actuator coupled to the optical filter, wherein the actuator is operatively configured to change the wavelength of light that passes through the optical filter along the optical axis.

3. An indicia reading terminal according to claim 2, wherein the optical filter comprise a plurality of the filter regions each of which is configured to pass emitted light that has different emission wavelengths, and wherein the actuator is operatively configured to move the optical filter to place one of the filter regions in position along the optical axis in response to the wavelength of the light generated by the illumination source.

4. An indicia reading terminal according to claim 1, further comprising an imaging lens for use in focusing an image of the decodable indicia onto the image sensor.

5. An indicia reading terminal according to claim 1, wherein the illumination source comprises one or more of:

a light emitting diode assembly for generating a first light beam having a first wavelength for illuminating the printing material; and

an aimer assembly comprising a laser diode for generating a second light beam of laser light.

6. An indicia reading terminal according to claim 1, wherein the optical filter comprises at least one optical coating disposed on one or more of the pixels, and wherein the optical coating forms at least one filter region that passes the emission wavelength of the emitted light.

7. An indicia reading terminal according to claim 6, wherein the optical coating forms a plurality of the filter regions each of which comprise different ones of the pixels, and wherein each of the filter regions is configured to pass emitted light that has different emission wavelengths.

8. An indicia reading terminal according to claim 1, wherein the optical filter comprises a plurality of the filter regions each of which is operatively configured to pass emitted light that has different emission wavelengths.

9. An indicia reading terminal according to claim 1, wherein the illumination source is operatively configured to provide light at a plurality of wavelengths.

10. An indicia reading terminal according to claim 1, further comprising a lens assembly optically coupled to the image sensor, wherein the optical filter comprises at least one optical coating layer disposed on the lens assembly, and wherein the optical coating passes the emission wavelength of the emitted light.

11. An indicia reading terminal according to claim 1, wherein the optical filter blocks all other wavelengths other than the emission wavelength.

12. An indicia reading terminal according to claim 1, wherein the optical filter comprises at least one optical coating disposed on a portion of the pixel array, and wherein the optical coating passes the emission wavelength of the emitted light.

13. An indicia reading terminal according to claim 1, wherein the color pixels are at spaced apart positions among the plurality of pixels in the pixel array.

14. An indicia reading terminal according to claim 1, wherein the optical filter comprises a substrate that has separate pass-bands for wavelengths consistent with red, green, and orange light.

15. A method of decoding decodable indicia comprising a printed material visible in response to light in a non-visible spectrum, said method comprising:

aligning on an optical axis an image sensor and an optical filter, the optical filter comprising at least one filter region having a pass-band for passing an emission wavelength of light emitted by the printing material;

generating light from an illumination source, the light having a wavelength in the non-visible spectrum; and

setting one or more of the wavelength of the light for illuminating the decodable indicia and the pass-band for the optical filter by correlating each of the wavelength and the pass-band to a successful decode of the decodable indicia.

16. A method according to claim 15, further comprising positioning the filter region of the optical filter along the optical axis with an actuator coupled to the optical filter.

17. A method according to claim 16, wherein the optical filter comprise a plurality of the filter regions each of which is configured to pass emitted light that has different emission wavelengths, and wherein the actuator is operatively configured to move the optical filter to place one of the filter regions in position along the optical axis in response to the wavelength of the light generated by the illumination source.

18. A method according to claim 15, further comprising receiving instruction by manual activation of a trigger depressed by an operator, wherein the trigger causes at least one attempt to decode the decodable indicia, and wherein one or more of the pass-band of the optical filter and the wavelength of the light generated by the illumination source are changed based the attempt to decode the decodable indicia.