Image sensing device with non-linear converting means

DETAILED DESCRIPTION This invention is directed to the solution of these problems of the prior art.
It is, therefore, the principal object of this invention to provide an image sensing device which has the optimum dynamic range and is capable of giving adequate pictures both in the field and frame modes.
It is another object of this invention to provide an image sensing device which is capable of preventing occurrence of blooming even if field reading is performed with a transfer CCD which has a small saturation potential and is designed for frame reading.
To attain this object, an image sensing device arranged according to this invention to permit selection between the field mode and the frame mode is provided with knee effect change-over means for changing the knee effect on the output signal of the image sensor from one value over to another in such a way as to give images with the optimum dynamic range both in the field mode and in the frame mode.
Further, to attain the above stated object, an image sensing device arranged as another embodiment of the invention is provided with overflow level change-over means for changing one overflow level over to another level for each of picture elements in response to a selection made between field reading and frame reading.
With a transfer CCD which has a small saturation potential employed as the image sensor, the above stated arrangement of the embodiment effectively prevents occurrence of blooming because the saturation potential of the transfer CCD is never exceeded by virtue of the overflow control even in the event of field reading.
Other objects and features of this invention will become apparent from the following detailed description of embodiments thereof taken in connection with the accompanying drawings.