OPTICAL READING DEVICE, OPTICAL READING METHOD, AND PROGRAM

摘要

An optical reading device authenticates an identification medium with cholesteric liquid crystal layer, having a structure in which no movable parts are necessary for switching circular circularly polarized light filter. The optical reading device reads an image from an identification medium having a cholesteric liquid crystal layer having a hologram processed, and an ink printed pattern layer in this order, and the device includes a light emitting part in which a right circularly polarized light filter is arranged in front of an LED, a light emitting part in which a right circularly polarized light filter is arranged in front of an LED, and a controlling part which switches light emission between the light emitting parts.

主权项

1. An optical reading device for reading an image from an identification medium, the identification medium comprising:
a cholesteric liquid crystal layer in which a hologram is processed; and an ink printed pattern layer, the layers arranged in this order from a reading surface, the optical reading device comprising:
a primary light emitting means;a primary circularly polarized light filter arranged in front of the primary light emitting means and which selectively transmits circularly polarized light of a primary rotating direction,a secondary light emitting means;a secondary circularly polarized light filter arranged in front of the secondary light emitting means and which selectively transmits circularly polarized light of a secondary rotating direction opposite to the primary rotating direction; anda controlling means that controls selecting one of two kinds of irradiation, one is irradiation of the circularly polarized light of the primary rotating direction from the primary circularly polarized light filter to the identification medium, and the other is irradiation of the circularly polarized light of the secondary rotating direction from the secondary circularly polarized light filter to the identification medium.