Linear image sensor having some parts selectively read or disabled

Abstract

The sensor 12 of a telecine projector is a charge coupled device and comprises a line of photo-sensitive elements 42 and a line of associated storge elements 44. An image form cinematographic film generates packets of charge in the elements 42 when focussed on the sensor. The charge packets may be transferred to the storage elements 44. The packets may then be shifted along the line of storage elements for reading (in serial form) by control circuitry 24. Reading takes place through an output port 26 at the end of the line. A switch 28 enables the two halves of the line to be disconnected, so that signals from only the lower half of the array can be read through the port 26, the signals from the upper half being discarded into a current sink. This reduces the clock frequency necessary to read out the signals in a set time, and enables the array to cope with normal, wide angle or anamorphic film stock.