Apparatus and method for reading data from an image detector

A method for reading image data from a detector array having individual photodetectors arranged in n rows and m columns, where m and n are integers, with at least a portion of the photodetectors in each column being connected by a switch means to a common column output line, said method comprising the steps of:

• (a) applying signals from the photodetectors in an initial group of rows at the center of the detector array to the column output lines;
• (b) applying signals from the photodetectors in a group of rows on one side of the initial group of rows to the column output lines;
• (c) applying signals from the photodetectors in a group of rows on the other side of the initial group of rows to the column output lines;
• and
• (d) repeating steps b and c until signal from all of the rows of photodetector have been applied to the column output lines.

A method for reading image data from an array of photodetectors arranged in n rows and m columns with at least a portion of the photodetectors in each column being connected by a selector means to a separate output line for that column, said method comprising the steps of:

• (a) activating given selector means to apply signals from the photodetectors in a group of p rows simultaneously to the output lines;
• (b) producing a plurality of combined output signals, each of which being produced by additively combining the signals from a group of q output lines;
• and
• (c) repeating steps a and b for other group of rows in the detector array;
• where m, n, p and q are integers where both p and q are greater than one.