US Patent 7664312 Information input and output method using dot pattern

Making a dot pattern so that misalignment in a x direction and a y direction is alternately generated for every adjacent information dots on a virtual grid line, the misalignment is alternately generated in the x direction and the y direction for each dot and this results in that the alternate information dot is necessarily arranged on the same grid line. Therefore, in the case that an optical reading apparatus reads the dot pattern, a search algorithm of a virtual grid line is simplified on an image memory. As a result, the grid point on the image memory is also easy. Therefore, without using a complicated program, it is possible to speed up the reading speed of the dot pattern.