System for inspecting an apparatus of a printed circuit board

An image pickup apparatus for use in an inspection system for inspecting an object of a circuit component installed on a board, said image pickup apparatus comprising:

• an image pickup device operable to scan an image of the object to be inspected and generate an image signal, said image pickup device having a fixed position;
• a linear moving device operable to move the inspection object installed on the board along the single axis;
• an encoder operable to directly detect a movement amount of the inspection object moved by said linear moving device and generate a detecting signal corresponding to the movement amount;
• a timing signal generating device operable to generate an image pickup start timing signal to be supplied to said image pickup device based on the detecting signal generated by said encoder;
• a time measuring device operable to measure an image storing time based on the image pickup start timing signal supplied from said timing signal generating device;
• and
• a normalizing calculation device operable to normalize the image signal supplied from said image pickup device according to the image storing time fed from said time measuring device;
• wherein said encoder has a roller part which is in direct contact with a portion of the board where there is no circuit component installed thereon.