Data reading apparatus

• US 6,364,209 B1
• Filed: 02/15/2000
• Issued: 04/02/2002
• Est. Priority Date: 02/17/1999
• Status: Expired due to Fees

• Current Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Original Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Inventors: Matsui, Akira, Tatsuta, Seiji
• Primary Examiner(s): Lee, Michael G.
• Assistant Examiner(s): WALSH, DANIEL I
• Application Number:
  US09/503,147
• Time in Patent Office: 777 Days
• Field of Search: 235/494, 235/492, 235/454, 235/493, 235/460
• US Class Current: 235/494
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 7/1443 locating of the code in an image
• CPC Class Codes: G11B 7/0033 with cards or other card-like flat carriers, e.g. flat sheets of optical film
• CPC Class Codes: G11B 7/013 for discrete information, i.e. where each information unit is stored in a distinct discrete location , e.g. digital information formats within a data block or sector

Abstract

A dot code contains a plurality of data dots arranged according to the data to be recorded and markers providing data dot read reference points for reading the data dots and showing a predetermined relationship relative to the data dots in terms of a predetermined physical characteristic quantity, the data dots and the markers being arranged to show a predetermined positional relationship according a predetermined format. The parameter setting section determines parameters necessary for the marker detecting section to detect markers from the dot code image stored in the image data storage section. The parameters are determined on the basis of the relationship between the markers and the data dots in terms of the predetermined physical characteristic quantity in such a way that markers are detected firstly without detecting data dots.

Claims

1. A data reading apparatus comprising:

an imaging section for picking up an image of an optically readable dot code containing a plurality of data dots arranged according to data to be recorded and markers providing data dot read reference points for reading the data dots and showing a predetermined relationship relative to the data dots in terms of a predetermined physical characteristic quantity, said data dots and said markers being arranged to show a predetermined positional relationship;

an image data storage section for storing image data of the dot code picked up by said imaging section;

a parameter setting section for setting parameters to be used for detecting markers based on the relationship between the data dots and the markers in terms of the predetermined physical characteristic quantity;

a marker detecting section for detecting markers from the image data stored in said image data storage section based on the parameters set by said parameter setting section;

a data dot read reference points determining section for determining the data dot read reference points for reading the data dots of the dot code based on the markers detected by said marker detecting section; and

a data dot reading section for reading the data dots by referring to the data dot read reference points determined by said data dot read reference points determining section;

wherein said parameter setting section is adapted to determine parameters suitable for detecting markers firstly without detecting data dots from the image data of the dot code stored in said image data storage section based on the relationship between the data dots and the markers in terms of said physical characteristic quantity.

2. The data reading apparatus according to claim 1, wherein:

said parameter setting section includes a parameter storage section for storing in advance a parameter determined based on the relationship between the markers and the data dots in terms of said physical characteristic quantity in order to detect markers firstly without detecting data dots.

3. The data reading apparatus according to claim 2, wherein:

said parameter storage section stores a plurality of parameters that are different from each other; and

said parameter setting section includes a parameter setting sequence controlling section for sequentially selecting parameters out of said plurality of parameters on a one by one basis in an order good for detecting markers firstly from the image data stored in said image data storage section without detecting data dots.

4. The data reading apparatus according to claim 3, wherein:

said parameter storage section divides a total variable range of the physical characteristic quantity of the markers to be detected by said marker detecting section into a plurality of ranges based on the relationship between the markers and the data dots in terms of the physical characteristic quantity and based on the total variable range so as to detect markers firstly without detecting data dots and stores a plurality of parameters for each of the ranges of the physical characteristic quantity of the markers to be detected.

5. The data reading apparatus according to claim 1, wherein:

said parameter setting section includes a parameter computing section for computationally determining parameters to be used for detecting markers firstly without detecting data dots based on the relationship between the markers and the data dots in terms of said physical characteristic quantity.

6. The data reading apparatus according to claim 5, wherein:

said parameter setting section includes a parameter computing sequence controlling section for controlling operation of said parameter computing section so as to make said parameter computing section computationally determine parameters in a sequence good for detecting markers firstly without detecting data dots from the image data stored in said image data storage section.

7. The data reading apparatus according to claim 6, wherein:

said parameter computing section divides a total variable range of the physical characteristic quantity of the markers to be detected by said marker detecting section into a plurality of ranges based on the relationship between the markers and the data dots in terms of the physical characteristic quantity and based on the total variable range so as to detect markers firstly without detecting data dots and computationally determines said parameters in a sequence good for detecting markers having the physical characteristic quantity of each of the ranges.

8. The data reading apparatus according to claim 1, wherein:

said marker detecting section further includes a judging section for determining if one or more than one of the markers are detected by means of the parameters set by said parameter setting section.

9. The data reading apparatus according to claim 1, wherein:

said marker detecting section detects markers by means of a marker detecting method adapted to the parameters set by said parameter setting section.

10. The data reading apparatus according to claim 1, wherein:

said physical characteristic quantity represents values indicating sizes of said markers and said data dots; and

the parameters set by said parameter setting section are threshold values for processing said markers and said data dots depending on their sizes.

11. The data reading apparatus according to claim 10, wherein:

the parameters set by said parameter setting section include a marker detecting region to be used by said marker detecting section for detecting markers from the image data stored in said image data storage section.

12. The data reading apparatus according to claim 10, wherein:

said marker detecting section detects a plurality of markers from the image data stored in said image data storage section; and

said data dot read reference points determining section determines the data dot read reference points based on the plurality of markers detected by said marker detecting section;

the parameters set by said parameter setting section include a marker detecting region to be used by said marker detecting section for detecting the markers other than a first marker detected by said marker detecting section based on the detected first marker.

13. The data reading apparatus according to claim 10, wherein:

said dot code further contains a plurality of pattern dots arranged with a predetermined positional relationship relative to said data dots and said markers and used for determining said data dot read reference points; and

said data dot read reference points determining section includes a pattern dot detecting section for detecting the pattern dots by referring to positions of the markers detected by said marker detecting section and is arranged to define said data dot read reference points based on the pattern dots detected by said pattern dot detecting section;

the parameters set by said parameter setting section include a pattern dot detecting region for the pattern dot detecting section to detect pattern dots therefrom based on the positions of the markers detected by said marker detecting section.

14. The data reading apparatus according to claim 1, wherein:

said physical characteristic quantity represents values indicating optical densities of said markers and said data dots; and

the parameters set by said parameter setting section are threshold values for processing said markers and said data dots depending on their optical densities.

15. The data reading apparatus according to claim 14, wherein:

the parameters set by said parameter setting section include a marker detecting region to be used by said marker detecting section for detecting markers from the image data stored in said image data storage section.

16. The data reading apparatus according to claim 14, wherein:

said marker detecting section detects a plurality of markers from the image data stored in said image data storage section; and

said data dot read reference points determining section determines data dot read reference points based on the plurality of markers detected by said marker detecting section;

the parameters set by said parameter setting section include a marker detecting region to be used by said marker detecting section for detecting the markers other than a first marker detected by said marker detecting section based on the detected first marker.

17. The data reading apparatus according to claim 14, wherein:

said dot code further contains a plurality of pattern dots arranged with a predetermined positional relationship relative to said data dots and said markers and used for determining said data dot read reference points; and

said data dot read reference points determining section includes a pattern dot detecting section for detecting the pattern dots by referring to positions of the markers detected by said marker detecting section and is arranged to define said data dot read reference points based on the pattern dots detected by said pattern dot detecting section;

the parameters set by said parameter setting section include a pattern dot detecting region for the pattern dot detecting section to detect pattern dots therefrom based on the positions of the markers detected by said marker detecting section.

18. The data reading apparatus according to claim 1, wherein said parameter setting section includes:

a characteristic quantity extracting section for extracting a physical characteristic quantity relating to at least one of the markers detected by said marker detecting section from said at least one marker; and

a parameter resetting section for resetting parameters for said marker detecting section as determined based on the physical characteristic quantity relating to said at least one marker extracted by said characteristic quantity extracting section.

19. The data reading apparatus according to claim 18, wherein:

said parameter setting section sets parameters to be used for a next picked up image for each image picked up by said imaging section.

20. The data reading apparatus according to claim 19, wherein:

said marker detecting section further includes a judging section for determining if one or more than one of the markers are detected by means of the parameters set by said parameter setting section; and

said parameter setting section determines parameters to be used for detecting markers firstly without detecting data dots based on the relationship between the markers and the data dots in terms of said physical characteristic quantity when said judging section determines that no marker is detected.