CCD Camera

In a system for observing a radiation emitting scene with a camera having an array of CCD elements each of which operate to produce a charge of magnitude dependent upon the exposure time and intensity of radiation received thereby, the camera and scene having relative motion and the array transferring the charges on the CCD elements periodically to output means so that the output means receives signals indicative of the radiation from successive portions of the scene, the improvement comprising:

• radiation transmitting means operable between a time T.sub.a and a time T.sub.b to expose the array to radiation from a first portion of the scene;
• timing means operable subsequent to time T.sub.b to transfer the charge on the CCD array to output means;
• adjusting means responsive to the relative speed of the camera and the scene connected to the radiation transmitting means and operable between a time T.sub.c and a time T.sub.d to expose the array to radiation from a second portion of the scene, the period between T.sub.b and T.sub.c being adjusted in accordance with the relative speed so that the first and second portions of the scene are substantially adjacent;
• and
• sensing means responsive to the intensity of radiation from the scene and connected to the radiation transmitting means to adjust the period between time T.sub.a and time T.sub.b and the period between time T.sub.c and time T.sub.d in accordance with changes in the intensity of radiation from the scene so as to maintain the charge transferred to the output means proximate the predetermined average level.

A camera useable to produce an output indicative of a scene that produces radiation which varies in intensity, the scene and the camera having relative motion which varies in speed comprising:

• a CCD array;
• optical means for directing radiation from the scene to the CCD array;
• a first clock;
• a second clock;
• a first shift register;
• a transfer gate connected to the array, to the first clock and to the first shift register to transfer signals from the array to the first shift register upon receipt of a clock signal from the first clock, the shift register producing an output signal indicative of the transferred signals from the array upon receipt of a clock signal from the second clock;
• selector means connected to receive the output from the first shift register and operable upon receipt of an input signal to transfer the output from the first shift register to a resultant output and to discard the output from the first shift register in the absence of an input signal;
• computer means;
• speed sensing means connected to the computer means to supply a signal thereto indicative of the relative speed of the camera and the scene;
• and
• intensity sensing means connected to the computer means to supply a signal thereto indicative of the intensity of radiation from the scene, the computer means having a first output connected to the first clock to vary the times of transfer of signals from the array to the first shift register in accordance with the signals from the speed sensing means and the intensity sensing means, the computer means having a second output connected to the selector means to supply the input signal to the selector means in accordance with the signals from the speed and intensity sensing means.