| 摘要 |
An apparatus for optically imaging features on a surface of a hand, comprising: a light source to illuminate an imaging area; a rotatable transparent cylinder having a cylindrical contact surface to contact the hand and configured to guide portions of the hand contacting the contact surface through the imaging area; and a detector positioned to intercept light from the imaging area and to generate therefrom a signal representative of surface features of the hand contacting the contact surface in the imaging area, the detector being configured to receive primarily light reflecting from the contact surface at an observation angle relative to a normal to the contact surface in the imaging area that is greater than a critical angle for an interface between the contact surface and water.
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