Method and apparatus for automatic correction of direct exposure apparatus

An automatic correction apparatus for a direct exposure apparatus comprising a plurality of exposure heads having exposure elements arranged in a two-dimensional manner with an inclination with respect to relative movement of an exposure target are arranged in a direction orthogonal to the direction of said relative movement, comprising:

• a sensor having two sensor sets in each of which two linear light detecting sensors that are parallel with each other are arranged at specific angles with respect to the direction in which said exposure heads are arranged, wherein said light detecting sensors are arranged so that said light detecting sensors in one of said sensor sets have said specific angle that is different from those in the other of said sensor sets;
• and
• moving means for moving said sensor, on the side where said exposure heads are illuminated, in the direction in which said exposure heads are arranged so that illumination of two exposure elements, which are included in adjacent ones of said exposure heads and which are to expose an identical line on said exposure target, among said exposure elements can be detected.