Patent ID: 8488236

Claim:
An optical system for a thermal image microscope, comprising: an image forming unit for forming a focus; and a relay unit for elongating an optical path, wherein the image forming unit comprises six lenses; the relay unit comprises two lenses; aspheric surfaces of the lenses are all convex surfaces; and the image forming unit comprises: a first lens having a first surface that is a concave surface having a negative refracting power toward an object and a first surface that is a convex surface having a positive refracting power toward an image; a second lens having a second surface that is a convex surface having a positive refracting power toward the object and a second surface that is a concave surface having a negative refracting power toward the image; a third lens having a third surface that is a convex surface having a positive refracting power toward the object and a third surface that is a concave surface having a negative refracting power toward the image; a fourth lens having a fourth surface that is convex surface having a positive refracting power toward the object and a fourth surface that is a concave surface having a negative refracting power toward the image; a fifth lens having a fifth surface that is a convex surface having a positive refracting power toward the object and a fifth surface that is a concave surface having a negative refracting power toward the image; and a sixth lens having a sixth surface that is a concave surface having a negative refracting power toward the object and a sixth surface that is convex surface having a positive refracting power toward the image; and the relay unit comprises: a seventh lens having a seventh surface that is a concave surface having a negative refracting power toward the object and a seventh surface that is a convex surface having a positive refracting power toward the image; and an eighth lens having an eighth surface that is a concave surface having a negative refracting power toward the object and an eighth surface that is a convex surface having a positive refracting power toward the image, which are sequentially arranged and become more distant from an object.