Patent ID: 8210434

Claim:
An error detecting apparatus for detecting an error in reading a two-dimensional code pattern, the two-dimensional code pattern comprising a plurality of information blocks each of which includes an information pattern and a boundary pattern, the information pattern including a plurality of first pattern images each of which corresponds to first information data and a plurality of second pattern images each of which corresponds to second information data, the boundary pattern indicating a boundary position, said error detecting apparatus comprising: a reading device for obtaining an image read signal by reading the two-dimensional code pattern in each reading range corresponding to a size which is equal to or more than a size of the information block; a reference point detecting device for detecting an intersection in the boundary pattern, as a block reference point, from the image read signal; an extracting device for extracting each of the first information data and the second information data, on the basis of one portion of the plurality of first pattern images and the plurality of second pattern images which belong to an information data extraction area, the information data extraction area being determined in accordance with a position in the reading range at which the block reference point exists, the information data extraction area being referred to in order to extract each of the first information data and the second information data; and an error detecting device for detecting whether or not there is an error in at least one of the first information data and the second information data extracted by said extracting device, on the basis of another portion of the plurality of first pattern images and the plurality of second pattern images which belongs to another area other than the information data extraction area, wherein the information block is provided with pixels arranged in M rows and N columns, the information block includes the first pattern images in a first quadrant area and a third quadrant area in the information block, and the information block includes the second pattern images in a second quadrant area and a fourth quadrant area in the information block.