| 摘要 |
An agile illumination apparatus for use in biometric authentication is disclosed. A controlled spot flash strobe forms and focuses a narrow illuminating beam so as to cover an area of interest for a biometric authentication of a target with a spot of light of constant size regardless of a distance of the target from the controlled spot flash strobe. A positioner can then be utilized to steer the narrow illuminating beam to a target in a monitored space. The spot size is kept constant and its irradiance distribution is kept uniform in order to deliver a constant amount of energy to the target irrespective of the distance, wherein the controlled spot flash strobe automatically reduces its power as the target moves closer to the controlled spot flash strobe in order to maintain a constant exposure value and provide for enhanced biometric authentication of the target.
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