Patent ID: 8179340

Claim:
A two-dimensional code pattern constructed by blocks of pixels arranged in N columns×M rows, comprising: a boundary pattern in which each pixel belonging to a predetermined first pixel group in each of said blocks is set into a turn-on state or a turn-off state by a predetermined light emitting pattern showing a boundary position; a rotation detection pattern in which each pixel belonging to a predetermined second pixel group in each of said blocks is set into the turn-on state or the turn-off state by a light emitting pattern which can detect a rotational angle upon reading of said block; and an information pattern in which in each of first to fourth quadrant regions in said block, both of each of said pixels belonging to said first quadrant region and each of said pixels belonging to said third quadrant region are set into the turn-on state or the turn-off state according to first information data and both of each of said pixels belonging to said second quadrant region and each of said pixels belonging to said fourth quadrant region are set into the turn-on state or the turn-off state according to second information data.