INFORMATION PATTERN CARRIER AND METHOD FOR OPTICALLY READING INFORMATION PATTERN

摘要

Provided is an information pattern carrier, wherein an information pattern (12) is made invisible by forming a mask (13) on the information pattern formed by colored ink or making the color of the colored ink the same as the ground color of an information recording medium (11) or the color of a colored underprint portion.  When the information recording medium (11) having the information pattern (12) is mounted on or carried into a predetermined position, excitation light (H1) having energy higher than that of the bandgap of semiconductor quantum dots is applied to the information pattern (12) from a light-emitting diode (15) to thereby thermally expand the semiconductor quantum dots.  Light having a wavelength that is shifted to the long-wavelength side is emitted from the thermally expanded semiconductor quantum dots, the emitted light is received by a light sensor (16) having sensitivity to a portion on the long-wavelength side of the shifted wavelength, and the information pattern (12) is read by an information determining unit (17).