LED array and partitive driving method therefor using overlapping activation periods

A light source array for an image read-out apparatus including a plurality of blocks having a plurality of light sources, each of said blocks being independently turned on or extinguished, said array comprising:

• illumination control means for turning on, after the lapse of a time period T1 after a first block is turned on, a succeeding block;
• extinguishment control means for extinguishing, after the lapse of a time period T2 after the succeeding block is turned on, the first block which has been turned on since the time before said succeeding block was turned on;
• and
• time control means for variably setting the time period T2 in accordance with the output signal of a signal source.

An image reading apparatus comprising:

• a light source array including a plurality of blocks having a plurality of light sources, each of said blocks being independently turned on or extinguished, said array further including illumination control means for turning on, after the lapse of a time period T1 after a first block is turned on, a succeeding block,
• extinguishment control means for extinguishing, after the lapse of a time period T2 after the succeeding block is turned on, the first block which has been turned on since the time before said succeeding block was turned on, and
• time control means for variably setting the time period T2 in accordance with the output signal of a signal source;
• and
• a line sensor for reading reflected light from an original illuminated by said light source array.

A partitive driving method for a light source array of an image read-out apparatus having a plurality of light source blocks each of which being independently turned on, said method comprising the steps of:

• turning on, after the lapse of a time period T1 after a block b is turned on, a succeeding block;
• extinguishing, after the lapse of a time period T2 after the block b is turned on, another block a which has been turned on before block b was turned on;
• and
• variably setting the time period T2 in accordance with the output of a signal source.