A solid state imager includes an arrangement for converting analog pixel values
to digital form on an arrayed per-column basis. An N-bit counter supplies an N-bit
DAC to produce an analog ramp output providing a ramp signal with a level that
varies corresponding to the contents of the counter. Latches or equivalent digital
storage elements are each associated with a respective column. A counter bus connects
the counter to latch inputs of said latches, and comparators associated the columns
gate the latches when the analog ramp equals the pixel value for that column. The
contents of the latch elements are transferred sequentially to a video output bus
to produce the digital video signal. There can be additionally black-level readout
latch elements, for storing a digital value that corresponds to the dark or black
video level, and a subtraction element subtracts the black level value from the
pixel value to reduce fixed pattern noise. An additional array of buffer latches
can be employed.