Patent ID: 6677603
Filing Date: 2004-01-13
Classification: G07D

Abstract:
A paper sheet discriminating device which irradiates lights of at least two or more wavelengths from a light source to a paper sheet and receives transmitting lights which transmit through said paper sheet by a photo sensor and performs the discrimination of said paper sheet in response to received light signals from said photo sensor, wherein the improvement being characterized in that said paper sheet discriminating device further includes reference value setting means which adjusts a light emission quantity of said light source such that the output of said photo sensor becomes a given value in a state that a reference medium is set between said light source and said photo sensor and also stores the output value of said photo sensor which directly receives light without the reference medium from said light source as an adjustment reference value in a memory part, and adjustment means which adjusts the light emission quantity of said light source such that the output value of said photo sensor which directly receives light without the reference medium from said light source is made to agree with the stored adjustment reference value;wherein lights of at least two or more wavelengths are commonly used as said light source and said paper sheet discriminating device further includes a light receiving circuit system which is comprised of an amplifying circuit for amplifying output signals from the photo sensor, a gain changeover circuit which changes over an output gain, an offset circuit which adjusts an offset and a separation circuit for separating output signals of said lights of respective wavelengths. 2.A paper sheet discriminating device according to claim 1, wherein said two or more wavelengths are two wavelengths of red light and infrared light.