Optical member inspecting apparatus and method of inspection thereof

An optical member inspection apparatus comprising:

• an inspection optical system, said inspection optical system including a light source;
• a diffuser positioned to diffuse the light emitted from said light source, said diffuser comprising a central portion and a peripheral portion, a diffusion transmittance of said peripheral portion being higher than a diffusion transmittance of said central portion;
• and an image pick-up positioned to receive light emitted from said light source and transmitted through said diffuser and an optical member to be inspected, whereby said image pick-up obtains an image of said optical member;
• and
• a processor, wherein said processor receives image signals output from said image pick-up and determines whether said optical member is defective based on said image signals;
• wherein said diffuser comprises a first diffusing plate and a second diffusing plate, which together determine said central portion and said peripheral portion, a shape of the one of said first and second diffusing plates that determines said central portion being similar to a shape of said optical member to be inspected and being positioned closer to said optical member to be inspected than the other of the first and second diffusing plates.

An optical member inspection apparatus, comprising:

• a plurality of inspection optical systems, each of said plurality of inspection optical systems consisting of:
• a light source;
• means for diffusing light emitted from said light source, said diffusing means comprising a central portion and a peripheral portion, a diffusion transmittance of said peripheral portion being higher than that of said central portion;
• and
• means for picking-up an image of an optical member to be inspected, said image pickup means being positioned to receive light emitted from said light source and transmitted through said diffusing means and said optical member;
• and
• means for judging whether or not said optical member has a defect in accordance with image signal output from said image pick-up means;
• wherein a ratio of a strength of light emitted from said central portion of said diffusing means and incident on said optical member and a strength of light emitted from said peripheral portion of said diffusing means and incident on said optical member, is set differently in each of said plurality of inspection optical systems.

An optical member inspection apparatus comprising:

• a plurality of inspection optical systems, each inspection optical system including a light source;
• a diffuser positioned to diffuse the light emitted from said light source, said diffuser comprising a central portion and a peripheral portion, a diffusion transmittance of said peripheral portion being higher than a diffusion transmittance of said central portion;
• and an image pick-up positioned to receive light emitted from said light source and transmitted through said diffuser and an optical member to be inspected, whereby said image pick-up obtains an image of said optical member;
• and
• a processor, wherein said processor receives image signals output from said image pick-up and determines whether said optical member is defective based on said image signals;
• wherein a ratio of a strength of light emitted from said central portion of said diffusing means and incident on said optical member and a strength of light emitted from said peripheral portion of said diffusing means and incident on said optical member is set differently in each of said plurality of inspection optical systems.