| 摘要 |
<p>A film video player (10) includes an electronic strobe light (12) operable for repetitively firing a flash tube (52), to flash illuminate a solid state image sensor (13) via a pulse of light projected onto a photographic film (14) at the vertical retrace rate of a standard television signal. Detector circuitry (25), responsive to a signal relating to an output of the image sensor, produces a control signal that is functionally related to whether or not the illumination of the image sensor is above, below, or within a predertermined range near the saturation level of the image sensor. A microprocessor (32) adjusts an exposure level signal at the vertical retrace rate in accordance with the control signal. Logic switching circuitry (62), having an input coupled to the microprocessor and responsive to the exposure level signal and an output coupled to the electronic strobe light, causes the electronic strobe light to produce a pulse of light within each vertical retrace interval that is sufficient to illuminate the image sensor near its saturation level, without the illumination saturating the sensor, to optimize the signal-to-noise of the image sensor.</p> |
