Picture taking optical reader

• US 20050001035A1
• Filed: 05/11/2004
• Published: 01/06/2005
• Est. Priority Date: 05/12/2003
• Status: Active Grant

• Current Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Longacre, Andrew Jr., Hussey, Robert M., Hawley, Thomas, Ehrhart, Michael A., Meier, Timothy P.
• Granted Patent: US 7,637,430 B2
• Time in Patent Office: Days
• US Class Current: 235/462.210
• CPC Class Codes: G06K 7/10851 Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device basic electronic circuitry H03

Abstract

An optical reader having a picture taking mode and a decode mode. In a picture taking mode, the reader captures and outputs a frame of image data without attempting to decode a decodable symbol in the frame. In the decode mode, the reader captures a frame of image data and attempts to decode a decodable symbol represented in the frame. The reader may have a decode mode in which light from an aiming light source is received by an image sensor.

Claims

1. A bar code decoding device comprising:

a portable housing;

a lens assembly focusing an image onto said two dimensional image sensor;

a control circuit in communication with said illumination assembly and said imaging assembly, wherein said control circuit is configured to operate in a “

decode mode” and

a “

picture taking mode”

; and

a user interface facilitating selection between said decode mode and said picture taking mode;

wherein said control circuit, when operating in said “

decode mode”

loads a “

decode mode”

initial exposure period value, captures a frame of image data utilizing said “

decode mode”

initial exposure period value, builds a histogram summarizing said captured frame, evaluates said histogram according to a “

decode mode”

histogram evaluation, and adjusts said initial exposure period value depending on an outcome of said evaluation;

wherein said control circuit, when operating in said “

picture taking”

mode loads a “

picture taking mode”

initial exposure period value, captures a frame of image data utilizing said initial “

picture taking mode”

initial exposure period value, builds a histogram summarizing said captured frame, evaluates said histogram according to a “

picture taking mode”

histogram evaluation criteria, and adjusts said initial exposure period value depending on an outcome of said evaluation,

wherein said “

decode mode”

initial exposure period value is less than said “

picture taking mode”

initial exposure period value.

2. The optical reader of claim 1, further comprising artificial light sources projecting light from said reader, wherein said at least one camera control parameter is one which maintains all of said artificial light sources “

OFF”

during a “

picture taking mode”

of operation.

3. The optical reader of claim 1, wherein said reader includes a display and wherein said user interface includes icons displayed on said display.

4. The optical reader of claim 1, wherein said control circuit is further configured to operate in an improvement mode in which said control circuit improves a visual output quality of a last captured image captured by said reader independent of whether said last captured image was captured in a “

decode mode”

or in a “

picture taking mode.”

5. The optical reader of claim 1, wherein said portable housing houses said illumination assembly, and wherein said portable housing is configured to be worn on a finger.

6. The optical reader of claim 1, wherein said control circuit in accordance with said “

decode mode”

histogram evaluation criteria determines whether a predetermined near-peak gray scale value of said histogram is above or below a middle range gray scale value.

7. The optical reader of claim 1, wherein said control circuit in accordance with said “

picture taking mode”

histogram evaluation criteria determines whether a median gray scale value of said histogram is above or below a middle range gray scale value.

8. The optical reader of claim 1, wherein said control circuit in accordance with said “

decode mode”

histogram evaluation criteria determines whether a predetermined near peak gray scale value of said histogram is above or below a middle range gray scale value, and wherein said control circuit in accordance with said “

picture taking mode”

histogram evaluation criteria determines whether a median gray scale value of said histogram is above or below a middle range gray scale value.

9. A bar code reader comprising:

an image sensor;

a control circuit in communication with said image sensor and controlling said image sensor to include overlapping frame exposure periods;

at least one illumination light sources projecting an illumination pattern;

at least one aiming light source projecting an aiming pattern onto a target substrate,

wherein said control circuit in at least one operating mode coordinates control of said at least one aiming light source so that said at least one light source is selectively turned “

OFF”

while pixels of said image sensor corresponding to said aiming pattern are being exposed.

10. The bar code reader of claim 9, wherein said image sensor is CMOS image sensor.

11. The bar reader of claim 9, wherein said aiming pattern is single horizontal line aiming pattern.

12. The bar code reader of claim 9, wherein said control circuit is operable in a user-selectable “

linear decode mode” and

a user selectable “

normal operating mode,”

wherein said control circuit in said “

linear decode mode”

maintains said at least one illumination light source “

OFF” and

said at least one aiming light source selectively “

ON”

while pixels corresponding to said aiming pattern are being exposed, and wherein said control circuit in said “

normal operating mode”

selectively turns said at least one aiming LED “

OFF”

while pixels of said image sensor corresponding to said aiming pattern are being exposed.

13. An optical reader comprising:

a two-dimensional image sensor including pixels;

a lens assembly;

an aiming and illumination system comprising at least one aiming light source and at least one illumination light source, wherein said reader is configured so that actuation of said at least on aiming light source projects an aiming pattern, and further so that actuation of said at least one illumination light source projects an illumination pattern, wherein said aiming pattern and said illumination pattern at least partially overlap;

a control circuit in communication with said two dimensional image sensor and said illumination system, said control circuit configured to operate in linear decode mode in which, during a frame exposure period, said aiming and illumination system projects said aiming pattern without projecting said illumination pattern.

14. The optical reader of claim 13, wherein said aiming pattern consist of a horizontal aiming line.

15. The optical reader of claim 13, wherein said aiming an illumination system and said control circuit are configured so that said control circuit preferentially processes image data corresponding to an area illuminated by said horizontal aiming line.

16. The optical reader of claim 15, wherein said control circuit in preferentially processing image data clocks out and captures a partial frame of image data corresponding to said area illuminated by said horizontal aiming line.

17. The optical reader of claim 15, wherein said control circuit in preferentially processing image data launches a scan line relative to pixel values representing said area illuminated by said horizontal aiming line.

18. The optical reader of claim 13, wherein said lens assembly is configured so that said reader has a fixed best focus distance of less than two feet.

19. The optical reader of claim 13, wherein said reader is configured to be driven into said linear decode mode on receipt of a command from a host computer.

20. The optical reader of claim 13, wherein said reader is configured to automatically cease operating in said linear decode mode if said control circuit fails to decode a symbol while operating in said linear decode mode.

21. An optical reader comprising:

a two-dimensional image sensor comprising a plurality of pixels;

an imaging assembly;

an aiming and illumination system comprising at least one aiming light source and at least one illumination light source, wherein said reader is configured so that actuation of said at least one aiming light source projects an aiming pattern, and further so that actuation of said at least one illumination light projects an illumination pattern;

a control circuit configured to operate in a first decode mode and a second decode mode, wherein said control circuit in said first decode mode simultaneously projects said aiming pattern and said illumination pattern during a frame exposure period so that said imaging assembly senses light from both of said at least one aiming light source and said illumination light source during said frame exposure period.

22. The optical reader of claim 21, wherein said aiming pattern consists of a horizontal aiming line.

23. The optical reader of claim 21, wherein said aiming an illumination system and said control circuit are configured so that said control circuit preferentially processes image data corresponding to an area illuminated by said horizontal aiming line.

24. The optical reader of claim 23, wherein said control circuit in preferentially processing image data clocks out and captures a partial frame of image data corresponding to said area illuminated by said horizontal aiming line.

25. The optical reader of claim 23, wherein said control circuit in preferentially processing image data launches a scan line relative to pixel values representing said area illuminated by said horizontal aiming line.

26. The optical reader of claim 23, wherein said reader is configured to automatically cease operating in said linear decode mode if said control circuit fails to decode a symbol while operating in said linear decode mode.

27. The optical reader of claim 21, wherein said control circuit during said normal decode mode selectively projects said aiming pattern intermediate frame exposure periods and selectively projects said illumination pattern during frame exposure periods.

28. An optical reader comprising:

a portable housing;

an illumination assembly;

an imaging assembly;

a control circuit;

a user interface enabling selection between modes of operation;

a picture taking mode executable by said control circuit in which said reader captures a frame of image data and without attempting to decode decodable symbol therein outputs said capture frame of image data;

a decode mode executable by said control circuit in which said control circuit captures a frame of image data and decodes a decodable symbol represented therein;

a picture improvement mode in which said optical reader improves a visual output quality of a last captured frame, wherein said reader is configured to be driven into said picture improvement mode irrespective of the mode of operation of the reader in during a most recent frame capture period.

29. The reader of claim 28, wherein said user interface includes displayed menu options.

30. The reader of claim 28, wherein said imaging assembly is configured so that said reader has a fixed best focus distance of less than two feet.

31. The reader of claim 28, wherein said menu interface includes menu symbols.

32. The reader of claim 28, wherein said menu interface facilitates selection of said picture taking mode, said decode mode and said improvement mode by input of a command into a remote device nonintegrated relative to said portable housing.

33. The reader of claim 28, wherein said control circuit in said picture improvement mode decreases a value of light pixel values and increases a value of dark pixel values.