Imaging barcode reader with color-separated aimer and illuminator

• US 10,055,625 B2
• Filed: 03/28/2017
• Issued: 08/21/2018
• Est. Priority Date: 04/15/2016
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Feng, Chen, Ren, Jie
• Primary Examiner(s): Labaze, Edwyn
• Application Number:
  US15/470,971
• Publication Number:
  US 20170300728A1
• Time in Patent Office: 511 Days
• Field of Search: 23546211, 2354621, 23546224, 23546241, 235375
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 2207/1011 Aiming
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10811 Focalisation
• CPC Class Codes: G06K 7/10881 constructional details of hand-held scanners
• CPC Class Codes: G06K 7/12 using a selected wavelength, e.g. to sense red marks and ignore blue marks
• CPC Class Codes: G06K 7/1417 2D bar codes

Abstract

A scanner for machine-readable symbols, such as barcodes and two-dimensional matrix symbols, employs at least two different light frequencies (colors). The first frequency supports accurate aiming of the scanner at a symbol. The second frequency supports illumination of a machine-readable symbol so that the reflected illumination light can be read at the second frequency by the scanner'"'"'s optical imaging element. Employing two different light frequencies enables both aiming and scanning to occur simultaneously, while the aiming process does not interfere with the scanning process. It enables the aiming frequency to be used for additional purposes, such as providing signaling to a user of the scanner. In an embodiment, two distinct light sources are used in the scanner to provide the different light frequencies. In an embodiment, various color filters are employed to separate and distinguish light frequencies. In an embodiment, signal processing may be employed to digitally distinguish multiple separate frequencies in light reflected from the symbol.

Claims

1. A scanner, comprising:

an aimer configured to provide aiming light comprising at least one aiming frequency to support aiming of the scanner at a machine-readable symbol (MRS);

an illuminator configured to provide reading light comprising at least one reading frequency which illuminates the MRS to support optical reading of the MRS; and

an imaging sensor having an optical filter configured to block the at least one aiming frequency and to transmit the at least one reading frequency, the imaging sensor configured to;

receive light reflected by the MRS, and

convert the reflected light to an electrical signal suitable for signal processing by the scanner;

wherein the illuminator comprises an illuminator filter configured to block the at least one aiming frequency.

2. The scanner of claim 1, wherein:

the aimer is configured to provide aiming light which consists essentially of a first frequency;

the illuminator is configured to provide reading light of a second frequency which is different from the first frequency; and

the imaging sensor is configured to be responsive to the second frequency and to not be responsive to the first frequency.

3. The scanner of claim 1, wherein:

the aimer is configured to provide aiming light which consists essentially of a first frequency;

the illuminator is configured to provide reading light of a second frequency which is different from the first frequency;

the optical filter is configured to block the first frequency and to transmit the second frequency; and

the optical filter is configured and arranged to filter along an optical path which conveys the light reflected from the MRS to the imaging sensor.

4. The scanner of claim 1, wherein:

the aimer is configured to provide aiming light which consists essentially of a first frequency;

the illuminator is configured to provide reading light of a second frequency which is different from the first frequency;

the optical filter is configured to block the first frequency and to transmit the second frequency; and

the optical filter is interposed between the image sensor and the MRS.

5. The scanner of claim 1, wherein:

the aimer is configured to provide aiming light which consists essentially of a first frequency;

the illuminator is configured to provide reading light comprising a plurality of frequencies, the plurality of frequencies comprising at least a second frequency which is different from the first frequency; and

the imaging sensor is configured to be responsive to at least the second frequency and to not be responsive to the first frequency.

6. The scanner of claim 1, wherein:

the aimer is configured to provide aiming light which consists essentially of a first frequency;

the illuminator is configured to provide reading light comprising a plurality of frequencies, the plurality of frequencies comprising at least a second frequency which is different from the first frequency;

the optical filter is configured to block the first frequency and to transmit the second frequency; and

the optical filter is configured and arranged to filter along an optical path which conveys the light reflected from the MRS to the imaging sensor.

7. The scanner of claim 1, wherein:

the aimer is configured to emit a first plurality of frequencies;

the at least one reading frequency being a frequency which is not emitted by the aimer; and

the imaging sensor is configured to be responsive to the at least one reading frequency.

8. The scanner of claim 7, wherein the aimer comprises:

an aimer light source which emits the first plurality of frequencies and emits the at least one reading frequency; and

an aimer filter configured to block the at least one reading frequency.

9. The scanner of claim 1, wherein:

the aimer is configured to emit a first plurality of frequencies;

the at least one reading frequency being a frequency which is not emitted by the aimer;

the optical filter is configured to transmit light of the least one reading frequency and block light of the first plurality of frequencies emitted by the aimer.

10. The scanner of claim 1, wherein the aimer is configured to generate a visual indicator of at least one of:

a data of the machine-readable symbol;

an instruction for operation of the electronic scanner;

an electronic scanner function;

an electronic scanner status; and

an electronic scanner activity.

11. The scanner of claim 10, wherein the aimer is configured to generate the visual indicator via at least one of:

an aimer light source which emits a plurality of colors;

a plurality of aimer light sources, each light source of the plurality emitting a different color;

an aimer filter configured to select a color from among a plurality of colors emitted by the aimer; and

an image projector element.

12. The scanner of claim 1, wherein:

the aimer and the illuminator are configurable to be operable simultaneously; and

the imaging sensor is configured to acquire the MRS while the aiming light is being emitted.

13. The scanner of claim 1, wherein the aimer is configured to emit a full-frame light pattern comprising a complete field-of-view of the MRS.

14. The scanner of claim 1, wherein the imaging sensor comprises:

a photosensitive element to convert the received reflected light to an electrical signal; and

a signal processing module configured to remove, from the electrical signal, a signal element representative of the aiming light reflected from the MRS.

15. A scanner, comprising:

an aimer to provide aiming light to support aiming of the scanner at a machine-readable symbol (MRS);

an illuminator to provide reading light which illuminates the MRS to support optical reading of the MRS; and

an imaging sensor comprising a light-to-electricity conversion element and a signal filter module, and configured so that upon receiving light reflected from the MRS;

the light-to-electricity conversion element converts the received light reflected from the MRS to a first electrical signal; and

the signal filter module performs a signal filtering operation to extract, from the first electrical signal, a second electrical signal representative of the received reading light suitable for determining a data content of the MRS by the scanner.

16. The scanner of claim 15, wherein the imaging sensor is configured to distinguish a first light frequency which is present in the reading light and which is not present in the aiming light.

17. The scanner of claim 16, comprising an optical bandpass filter configured to pass the first light frequency and to block a second light frequency.

18. The scanner of claim 15, wherein:

the imaging sensor is configured so that upon receiving light reflected from the MRS the imaging sensor distinguishes, in the received light, aiming light reflected from the MRS from reading light reflected from the MRS.

19. The scanner of claim 18, wherein the signal filtering module is configured to dynamically select, from among a plurality of frequencies of the received reading light, an optimum frequency to convert to the electrical signal suitable for determining the data content of the MRS.

20. The scanner of claim 19, wherein the selection of the optimum frequency is determined based on at least one of:

an ambient light spectrum impinging on the MRS; and

an optical signal-to-noise ratio optimization with respect to the imaging sensor.