Fingerprint detecting device having a fluid layer sealed in a gap

Abstract

A fingerprint detecting device includes a flat transparent body, a light source, a thin surface film layer, a fluid layer, and an image detection unit. The transparent body on which a skin surface of a finger is pressed has a surface constituted by a scattering surface with a fine three-dimensional unevenness. The light source irradiates incident light from an inside of the transparent body on the skin surface pressed against the surface of the transparent body. The surface film layer is formed on the surface of the transparent body via a small gap, on which a three-dimensional pattern of the skin surface is transferred by pressing the finger. The fluid layer is formed by sealing one of a gas and a liquid in the gap between the surface of the transparent body and the surface film layer, and is pressed by the surface film layer on which the three-dimensional pattern of the skin surface is transferred. The image detection unit detects an image fingerprint pattern on the basis of the light from the light source, the reflection of which is changed at the surface of the transparent body, when the surface film layer comes into contact with the surface of the transparent body in accordance with the three-dimensional pattern of the skin surface.

Dependencies are inferred from the claim text.