Abstract: In order to provide an apparatus which has a simple arrangement, can be easily adjusted, and can authenticate a bill, negotiable instrument, and the like with high reliability, adjustment is performed in advance in the absence of an identification target to equalize outputs from a photoelectric converter with respect to light sources A and B that emit light beams having different wavelengths. In this state, the difference in output between detection signals based on the light beams transmitted through an identification target is detected as an output from a high-pass filter. A sampling circuit samples a signal proportional to the difference in output between the detection values based on the light sources A and B, which is based on this output difference. Authentication is performed on the basis of the sampled value.

Abstract: In order to provide an apparatus which has a simple arrangement, can be easily adjusted, and can authenticate a bill, negotiable instrument, and the like with high reliability, adjustment is performed in advance in the absence of an identification target to equalize outputs from a photoelectric converter with respect to light sources A and B that emit light beams having different wavelengths. In this state, the difference in output between detection signals based on the light beams transmitted through an identification target is detected as an output from a high-pass filter. A sampling circuit samples a signal proportional to the difference in output between the detection values based on the light sources A and B, which is based on this output difference. Authentication is performed on the basis of the sampled value.

Abstract: In order to provide an apparatus which has a simple arrangement, can be easily adjusted, and can authenticate a bill, negotiable instrument, and the like with high reliability, adjustment is performed in advance in the absence of an identification target to equalize outputs from a photoelectric converter with respect to light sources A and B that emit light beams having different wavelengths. In this state, the difference in output between detection signals based on the light beams transmitted through an identification target is detected as an output from a high-pass filter. A sampling circuit samples a signal proportional to the difference in output between the detection values based on the light sources A and B, which is based on this output difference. Authentication is performed on the basis of the sampled value.

Abstract: A device and method for identifying a bank note with simple construction offering easy adjustment and a reliable performance independent of the environment under which it works. The device enables identification of a bank note printed in color with a genuine one by the method of adjusting the intensity of light emission so as to equalize sensitivity of a photoelectric transducer to a light source A and a light source B, emitting lights in different wavelengths when there is no object to be identified, detecting the difference in sensitivity of detected signals of light transmitted through or reflected by the object to be identified as output of a high-pass filter, and sampling, in a sampling circuit, a signal based on the sensitivity difference and proportional to the difference between detected value for light source A and sensitivity of light source B to conduct identification based on the sampling value.