Patent ID: 8908248
Filing Date: 2014-12-09
Classification: G03H,G07D

Abstract:
1. An image reading device comprising: a conveying unit for conveying an irradiated member that has a hologram area in a conveying direction; a hologram detecting unit for detecting the passage of the hologram area of the irradiated member to output a detecting signal; a first light source for applying light to an irradiated part in the hologram area of the irradiated member; a second light source separated from the first light source along the conveying direction of the irradiated member and applying light to an irradiated part in the hologram area after the first light source applied light to the irradiated part of the hologram area and the irradiated member is conveyed by a prescribed distance, wherein a magnitude of an irradiation angle of the second light source being different from a magnitude of a prescribed irradiation angle of the first light source; a lighting control unit for respectively controlling the first and second light sources to be turned on when the detecting signal of the hologram detecting unit is received; first and second rod lens arrays for respectively converging the lights of the first and second light sources reflected by the irradiated part of the hologram area, a respective optical axis of the first and second rod lens arrays being disposed orthogonal to the surface of the irradiated member wherein the second lens array is separated from the first lens array along the conveying direction of the irradiated member; a first sensor for receiving the light from the first light source reflected from the hologram area and converged by the first rod lens array to detect a first signal of a hologram in the hologram area of the irradiated member, a second sensor for receiving the light from the second light source reflected from the hologram area and converged by the second rod lens array to detect a second signal of the hologram in the hologram area of the irradiated member; and a controller for comparing output signals of the first and second sensors with each other to check whether a hologram in the hologram area of the irradiated member is true or false.