Patent ID: 6891620

Claim:
A measuring plate for use in a sensor utilizing the phenomenon of attenuation in total internal reflection comprising a dielectric block provided with a film layer to be brought into contact with a sample, a light source which emits a light beam, an incident optical system which causes the light beam to enter the dielectric block so that total internal reflection conditions are satisfied at the interface of the dielectric block and the film layer and various angles of incidence of the light beam to the interface can be obtained, and a photodetector means which detects the intensity of the light beam reflected in total internal reflection at the interface and detects a state of attenuation in total internal reflection, the measuring plate being for providing the dielectric block and the film layer and comprising a dielectric plate provided with a plurality of recesses each provided with a film layer and holding a sample in contact with the film layer, and a reflecting optical system including a reflecting surface which is formed on the dielectric plate for each of the recesses to cause the light beam emitted from the light source to impinge upon the interface between the film layer of the recess and the dielectric plate and/or to cause the light beam reflected at the interface between the film layer of the recess and the dielectric plate to travel toward a predetermined position.