Examination apparatus, method for controlling examination apparatus, system, light guide, and scale

An inspection module for obtaining a tissue image comprising:

• an objective lens for focusing a reflected light originated from the tissue to the imaging device,
• a plurality of LEDs that surround the optical axis of the objective lens and expose light to the tissue,
• a circular polarization filter comprising polarization state-regulating parts for exposing the light from the LEDs to the tissue directly or as circularly polarized light, and
• an alignment mechanism for aligning the polarization state-regulating parts with the position of the LEDs.

A method of controlling an inspection device comprising:

• an imaging device, and
• an inspection module for allowing the imaging device to take tissue images in a direct mode and a polarization mode at a same tissue position,
• the method comprising:
• adjusting the position of polarization state-regulating parts formed in a circular polarization filter through the inspection module positioned on a tissue, exposing light of LEDs directly from the LEDs to the tissue, and recording a first digital image;
• and
• readjusting the position of the polarization state-regulating parts formed in the circular polarization filter, exposing the light of the LEDs to the tissue after making the LEDs light as circularly polarized light, and recording a second digital image.