| 摘要 |
The system reflects scattered beam at valleys of fingerprint and detects reflected beam in area CCD producing image representation. A laser light source (1) emits a spherical beam (10) which is converted to a plane beam (11) in a collimating hologram (2). A diffuser (3) scatters the plane beam (11), producing a scattered beam (12). A triangular prism (4) absorbs the scattered beam (12) at ridges of a fingerprint, and reflects the scattered beam (12) at valleys of the fingerprint. A fingerprint image producing hologram (5) processes the reflected spherical beam (13) from the valleys and condenses a spherical beam representing the subject fingerprint upon an area CCD (6) to produce an electrical signal which is amplified and analysed in the amplifying and analysing circuit (19).
|
