Detection system and method for automatically adjusting gray scale

A method of automatically adjusting a gray scale of a detection system, comprising:

• detecting a gray scale of a substrate alignment image formed by a detection lens;
• and
• adding or removing a filter in a light path in which the detection lens forms the substrate alignment image according to the gray scale of the substrate alignment image so as to change the gray scale of the substrate alignment image.

A method of aligning a mask with a glass substrate, using a plurality of detection systems to align a plurality of mask alignment marks on a mask with a plurality of corresponding substrate alignment marks on the glass substrate to align the mask with the glass substrate, and comprising:

• detecting gray scales of the substrate alignment images formed by the detection lenses of the detection systems;
• and
• when the substrate alignment images of the detection systems have inconsistent gray scales, adding a filter in the light path in which the detection lens forms the substrate alignment image having a high gray scale in the detection system to reduce the gray scale of the substrate alignment image so that the gray scales of the substrate alignment images formed by the detection lenses in the detection systems are consistent.