Information reproducing system

• US 6,446,866 B1
• Filed: 01/28/1999
• Issued: 09/10/2002
• Est. Priority Date: 02/02/1998
• Status: Expired due to Fees

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Tatsuta, Seiji
• Primary Examiner(s): Lee, Michael G.
• Assistant Examiner(s): LEE, DIANE I
• Application Number:
  US09/239,439
• Time in Patent Office: 1,321 Days
• Field of Search: 235/494, 235/456, 235/462.01, 382/181, 382/192, 382/203
• US Class Current: 235/454
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence

Abstract

A representative marker sensing section senses one representative marker from a frame shot by an image input section. A pattern dot sensing section senses pattern dots on the basis of the representative marker. A data dot reading point determining section determines reading points. With this configuration, once one representative marker has been sensed from the imaging frame, pattern dots are sensed on the basis of the representative marker and data reading points are calculated. This not only avoids an adverse effect of the disappearance of markers or the occurrence of erroneous markers and prevents the block data from being partially lost but also reduces the marker sensing process, avoids code reproduction failure, and speeds up the processing.

Claims

1. An information reproducing system which optically reads a dot code from an information recording medium and reproduces the information, the information recording medium on which an optically readable dot code has been recorded, the dot code composed of blocks arranged in an array, each block including at least a data code made up of data dots arranged according to the contents of data related to the information to be reproduced, a pattern code placed so as to have a specific positional relationship with the data dots and made up of pattern dots to determine reading points for the data dots, and markers to sense the pattern dots placed so as to have a specific positional relationship with the pattern dots and recorded in a way different from the data dots and the pattern dots, the information reproducing system comprising:

image input means for shooting the dot code on the information recording medium;

representative marker sensing means for sensing only one of the markers as a representative marker on an imaging frame shot by said image input means;

pattern dot sensing means for sensing the pattern dots on the basis of the position of said one of the markers which is sensed as the representative marker by said representative marker sensing means;

data dot reading point determining means for determining a reading point for each data dot on the basis of the positions of the pattern dots sensed by said pattern dot sensing means;

data reading means for reading each data dot at the reading point determined by said data dot reading point determining means; and

data reproducing means for concatenating the data items in each block read by said data reading means and reproducing the information;

wherein said pattern dot sensing means includes;

pattern dot sensing reference point setting means for, on the basis of the position of said one of the markers which is sensed as the representative marker by said representative marker sensing means, setting a pattern dot sensing reference point serving as a reference position to sense the pattern dots,

pattern dot format storage means for storing the positional relationship between each pattern dot in the pattern code and the pattern dot sensing reference point in the form of a pattern dot format, and

pattern dot reading vector storage means for storing a pattern dot reading vector to determine sensing points for the pattern dots on the basis of the pattern dot sensing reference point, and

wherein said pattern dot sensing means is designed to move the sensing point for the each pattern dot according to the pattern dot reading vector, starting from the pattern dot sensing reference point on the basis of the stored pattern dot format.

2. The information reproducing system according to claim 1, wherein said representative marker sensing means is designed to set in the central portion of the imaging frame an area where at least one of the markers constituting a block shot in a readable condition by said image input means can be sensed and sense the single marker in the set area.

3. The information reproducing system according to claim 2, wherein said representative marker sensing means sets the first sensed marker candidate as a representative marker.

4. The information reproducing system according to claim 2, wherein said representative marker sensing means is designed to sense marker candidates and set the marker candidate whose feature value is closest to a specific target value as a representative marker.

5. The information reproducing system according to claim 1, wherein said representative marker sensing means sets the first sensed marker candidate as a representative marker.

6. The information reproducing system according to claim 1, wherein said representative marker sensing means is designed to sense marker candidates and set the marker candidate whose feature value is closest to a specific target value as a representative marker.

7. The information reproducing system according to claim 1, wherein said pattern dot sensing means further includes:

pattern dot sensing feasibility judging means for, before pattern dot sensing, judging whether a point obtained by extending the pattern dot reading vector by one block from the pattern dot sensing reference point exists in the frame shot by said image input means.

8. The information reproducing system according to claim 1, wherein said pattern dot sensing means includes:

adjacent marker sensing means for sensing a marker adjacent to the representative marker on the basis of the position of the representative marker sensed by said representative marker sensing means, and

pattern dot reading vector computing means for applying a marker pair made up of the representative marker and the adjacent marker to one of the marker pairs constituting the block and calculating a pattern dot reading vector from their positional relationship.

9. The information reproducing system according to claim 8, wherein said adjacent marker sensing means senses an adjacent marker in at least one adjacent marker sensing area determined by the size and position of the representative marker sensed by said representative marker sensing means and a predetermined allowed skew angle.

10. The information reproducing system according to claim 8, wherein said pattern dot reading vector computing means further includes pattern dot reading vector recomputing means for, when pattern dots cannot be sensed on the basis of the calculated pattern dot reading vector, applying a marker pair made up of the representative marker and the adjacent marker again to another marker pair constituting the block and recomputing the pattern dot reading vector.

11. The information reproducing system according to claim 1, wherein said pattern dot sensing means further includes pattern dot sensing position correcting means for correcting the pattern dot sensing position each time a pattern dot is sensed, in order to sense a pattern dot reliably.

12. The information reproducing system according to claim 11, wherein said pattern dot sensing means further includes means for, when a first pattern dot is sensed, calculating its centroid, correcting the pattern dot sensing position on the basis of the position of the centroid of the calculated pattern dot, and sensing a pattern dot again.

13. The information reproducing system according to claim 1, wherein said pattern dot sensing means senses pattern dots included in pattern codes sharing the pattern dot sensing reference point set by said pattern dot sensing reference point setting means.

14. The information reproducing system according to claim 1, wherein said data dot reading point determining means includes:

reading reference value computing means for calculating a reading reference point and a reading reference vector in data dots with a method of least on the basis of the positions of the pattern dots sensed by said pattern dot sensing means, and

reading point computing means for calculating reading points for the data dots on the basis of the reading reference point and reading reference vector calculated by said reading reference value computing means.

15. The information reproducing system according to claim 17, wherein said reading point computing means calculates reading points for block data using reading reference points and reading reference vectors.

16. The information reproducing system according to claim 14, wherein:

said pattern dot sensing means includes;

pattern dot sensing reference point setting means for setting a pattern dot sensing reference point serving as a reference position to sense the pattern dots on the basis of the position of said one of the markers which is sensed by said representative marker sensing means,

pattern dot format storage means for storing the positional relationship between each pattern dot in the pattern code and the pattern dot sensing reference point in the form of a pattern dot format, and

pattern dot reading vector storage means for storing a pattern dot reading vector to determine a sensing point for the pattern dots on the basis of the pattern dot sensing reference point, and

said pattern dot sensing means is designed to sense the pattern dots by moving the sensing point for the pattern dot according to the pattern dot reading vector, starting from the pattern dot sensing reference point, on the basis of the stored pattern dot format, and

said pattern dot reading vector storage means is designed to calculate a pattern dot reading vector according to the reading reference vector calculated by said reading reference value computing means and store the resulting vector.

17. The information reproducing system according to claim 16, wherein said pattern dot reading vector storage means is designed to relate the reading reference vectors calculated by said reading reference value computing means to the corresponding reading reference points, store them as pattern dot reading vectors, and selectively apply the stored pattern dot reading vectors in the next imaging frame on the basis of the positional relationship between the pattern dot sensing reference point and the stored reading reference point.

18. An information reproducing system which optically reads a dot code from an information recording medium and reproduces the information, the information recording medium on which an optically readable dot code has been recorded, the dot code composed of blocks arranged in an array, each block including at least a data code made up of data dots arranged according to the contents of data related to the information to be reproduced, a pattern code placed so as to have a specific positional relationship with the data dots and made up of pattern dots to determine reading points for the data dots, and markers to sense the pattern dots placed so as to have a specific positional relationship with the pattern dots and recorded in a way different from the data dots and the pattern dots, the information reproducing system comprising:

image input means for shooting the dot code on the information recording medium;

representative marker sensing means for sensing only one of the markers as a representative marker on an imaging frame shot by said image input means;

pattern dot sensing means for sensing the pattern dots on the basis of the position of said one of the markers which is sensed as the representative marker by said representative marker sensing means;

data dot reading point determining means for determining a reading point for each data dot on the basis of the positions of the pattern dots sensed by said pattern dot sensing means;

data reading means for reading each data dot at the reading point determined by said data dot reading point determining means; and

data reproducing means for concatenating the data items in each block read by said data reading means and reproducing the information;

wherein said pattern dot sensing means includes;

pattern dot sensing reference point setting means for setting a pattern dot sensing reference point serving as a reference position to sense the pattern dots on the basis of the position of said one of the markers which is sensed as a representative marker by said representative marker sensing means,

pattern dot format storage means for storing the positional relationship between each pattern dot in the pattern code and the pattern dot sensing reference point in the form of a pattern dot format, and

pattern dot reading vector storage means for storing a pattern dot reading vector to determine sensing points for the pattern dots on the basis of the pattern dot sensing reference point, and

wherein said pattern dot sensing means senses the pattern dots by moving the sensing point for the pattern dot according to the pattern dot reading vector, starting from the pattern dot sensing reference point, on the basis of the stored pattern dot format,

said data dot reading point determining means includes reading reference value computing means for calculating a reading reference point and a reading reference vector from the positions of the pattern dots sensed by said pattern dot sensing means,

said pattern dot sensing means further includes block skip vector computing/storage means for calculating a block skip vector on the basis of the reading reference vector calculated by said reading reference value computing means and storing the block skip vector, and

said pattern dot sensing reference point setting means is designed to set the next pattern dot sensing reference point on the basis of the reading reference point calculated by said reading reference value computing means and the block skip vector computed and stored by said block skip vector computing/storage means.

19. The information reproducing system according to claim 18, wherein said block skip vector computing/storage means is designed to relate the calculated block skip vectors on the present imaging screen to the corresponding reading reference points and store them and selectively apply the stored block skip vectors on the next imaging screen on the basis of the positional relationship between reading reference points and the stored reading reference points.

20. An information reproducing system which optically reads a dot code from an information recording medium and reproduces the information, the information recording medium on which an optically readable dot code has been recorded, the dot code composed of blocks arranged in an array, each block including at least a data code made up of data dots arranged according to the contents of data related to the information to be reproduced, a pattern code placed so as to have a specific positional relationship with the data dots and made up of pattern dots to determine reading points for the data dots, and markers to sense the pattern dots placed so as to have a specific positional relationship with the pattern dots and recorded in a way different from the data dots and the pattern dots, the information reproducing system comprising:

image input means for shooting the dot code on the information recording medium;

representative marker sensing means for sensing only one of the markers as a representative marker on an imaging frame shot by said image input means;

pattern dot sensing means for sensing the pattern dots on the basis of the position of said one of the markers which is sensed as the representative marker by said representative marker sensing means;

data dot reading point determining means for determining a reading point for each data dot on the basis of the positions of the pattern dots sensed by said pattern dot sensing means;

data reading means for reading each data dot at the reading point determined by said data dot reading point determining means; and

data reproducing means for concatenating the data items in each block read by said data reading means and reproducing the information,

wherein the dot code has blocks with the same contents placed at regular intervals of several blocks and recorded in such a manner that part of them may overlap with each other on an imaging frame by said image input means,

said data dot reading point determining means includes;

reading reference value computing means for calculating a reading reference point and a reading reference vector from the positions of the pattern dots sensed by said pattern dot sensing means, and

divided block data reading point computing means for calculating the data dot reading points for blocks with the same contents part of which are missing because they partially cover the end of the imaging screen, from the reading reference point and reading reference vector calculated by said reading reference value computing means, and

wherein said data reading means includes divided block data concatenation reading means for reading data dots on the basis of the reading points calculated by said divided block data reading point computing means and concatenating the divided block data items into a single block data item.

21. The information reproducing system according to claim 20, wherein said data dot reading point determining means is designed to calculate a reading reference point and a reading reference vector from the block and the positions of pattern dots near the block to calculate reading points for the block data part of which is missing because the block partially covers the end of the imaging frame.

22. The information reproducing system according to claim 20, wherein said divided block data reading point computing means is designed to extrapolate a reading reference point and reading reference vector calculated from a pattern code imaged without any loss to calculate reading points for the block data part of which is missing because the block partially covers the end of the imaging screen.

23. An information reproducing system which optically reads a dot code from an information recording medium and reproduces the information, the information recording medium on which an optically readable dot code has been recorded, the dot code composed of blocks arranged in an array, each block including at least a data code made up of data dots arranged according to the contents of data related to the information to be reproduced, a pattern code placed so as to have a specific positional relationship with the data dots and made up of pattern dots to determine reading points for the data dots, and markers to sense the pattern dots placed so as to have a specific positional relationship with the pattern dots and recorded in a way different from the data dots and the pattern dots, the information reproducing system comprising:

image input means for shooting the dot code on the information recording medium;

representative marker sensing means for sensing only one of the markers as a representative marker on an imaging frame shot by said image input means;

pattern dot sensing means for sensing the pattern dots on the basis of the position of said one of the markers which is sensed as the representative marker by said representative marker sensing means;

data dot reading point determining means for determining a reading point for each data dot on the basis of the positions of the pattern dots sensed by said pattern dot sensing means;

data reading means for reading each data dot at the reading point determined by said data dot reading point determining means; and

data reproducing means for concatenating the data items in each block read by said data reading means and reproducing the information,

wherein said image input means includes;

lighting means for lighting dot codes to be imaged,

imaging means for shooting dot codes,

peak value sensing means for sensing the maximum value and minimum value of luminance from the frame shot by said imaging means,

exposure control means for controlling the amount of lighting by said lighting means or the amount of exposure, such as the exposure time, by said imaging means so that the maximum value of luminance sensed by said peak value sensing means may lie in a specific range, and

binarizing means for binarizing the frame shot by said imaging means according to a threshold value determined on the basis of the maximum value and minimum value of luminance sensed by said peak value sensing means, and

wherein said peak value sensing means is designed to sense the maximum value from an area where an increase in the luminance due to direct reflection is smaller than a specific allowed value even for an allowed lifting or tilting of the imaging device.

24. An information reproducing system which optically reads a dot code from an information recording medium and reproduces the information, the information recording medium on which an optically readable dot code has been recorded, the dot code composed of blocks arranged in an array, each block including at least a data code made up of data dots arranged according to the contents of data related to the information to be reproduced, a pattern code placed so as to have a specific positional relationship with the data dots and made up of pattern dots to determine reading points for the data dots, and markers to sense the pattern dots placed so as to have a specific positional relationship with the pattern dots and recorded in a way different from the data dots and the pattern dots, the information reproducing system comprising:

image input means for shooting the dot code on the information recording medium;

representative marker sensing means for sensing only one of the markers as a representative marker on an imaging frame shot by said image input means;

pattern dot sensing means for sensing the pattern dots on the basis of the position of said one of the markers which is sensed as the representative marker by said representative marker sensing means;

data dot reading point determining means for determining a reading point for each data dot on the basis of the positions of the pattern dots sensed by said pattern dot sensing means;

data reading means for reading each data dot at the reading point determined by said data dot reading point determining means; and

data reproducing means for concatenating the data items in each block read by said data reading means and reproducing the information;

wherein said image input means includes;

lighting means for lighting dot codes to be imaged,

imaging means for shooting dot codes,

peak value sensing means for sensing the maximum value and minimum value of luminance from the frame shot by said imaging means,

exposure control means for controlling the amount of lighting by said lighting means or the amount of exposure, such as the exposure time, by said imaging means so that the maximum value of luminance sensed by said peak value sensing means may lie in a specific range, and

binarizing means for binarizing the screen shot by said imaging means according to a threshold value determined on the basis of the maximum value and minimum value of luminance sensed by said peak value sensing means, and

wherein said peak value sensing means is designed to sense the minimum value from an area where a decrease in the luminance due to shading is smaller than a specific allowed value for an allowed lifting or tilting of the imaging device.