| 摘要 |
<p>The present invention relates to a device for scanning the surface of a generally cylindrical object carrying a raised pattern thereon so as to detect that pattern, notably for scanning a finger, which device comprises: a) a transparent optical body (2) having a substantially arcuate configuration about a first axis and having a convergent radial cross-section, and a channel (5) parallel to and substantially co-axial with that axis, which channel (5) presents a face substantially parallel to the said axis, upon which the object whose surface is to be observed can be placed, and the underside of which face serves as the optical base face to the convergent radial cross-section to the body (2); b) a source of incident light (100) adapted to be directed onto a light entry face (105) of the convergent cross-section of the body (2), the configuratin of the body (2) being such that the incident light is adapted to strike the underside of the said base face at substantially the angle of total internal reflection for the material from which the body (2) is fabricated and to be reflected through a light exit face of the convergent cross-section of the body (2); c) means for causing the incident light from said source (100) to illuminate the surface of an object placed in contact with the planar face of the channel (5); and d) a means for observing the light reflected from the underside of the base face through a light exit face of the convergent cross-section of the body (2) and for providing a signal dependent upon the intensity of the light detected. The invention also provides a method for scanning an article to detect a raised pattern thereon and a novel optical body for use in the method or device of the invention.</p> |
