Endoscope and diaphragm of endoscope

An endoscope, comprising:

• a tube unit, which is inserted into a portion to be observed;
• and
• an optical imaging system, which is arranged inside the tube unit, wherein the optical imaging system comprises a diaphragm;
• wherein the diaphragm is provided with a through-hole at a middle of the diaphragm along a radial direction of the diaphragm, wherein the through-hole forms a first light-transmitting region;
• the diaphragm is further provided with a second light-transmitting region, which is located outside the first light-transmitting region along a radial direction of the first light-transmitting region;
• wherein the second light-transmitting region is configured to absorb a light within a first wavelength range and transmit a light within a second wavelength range;
• wherein a wavelength value of the first wavelength range is less than a wavelength value of the second wavelength range.

A diaphragm for an optical imaging system of an endoscope, comprising:

• a first light-transmitting region, which is located at a middle of the diaphragm along a radial direction of the diaphragm;
• and
• a second light-transmitting region, which is located outside the first light-transmitting region along a radial direction of the first light-transmitting region;
• wherein the first light-transmitting region is configured to transmit a light within a first wavelength range and a light within a second wavelength range;
• the second light-transmitting region is configured to absorb the light within the first wavelength range and transmit the light within the second wavelength range;
• wherein the light within the first wavelength range is a light that is reflected after a light source of the endoscope irradiates the portion to be observed, and the light within the second wavelength range is fluorescence that is generated by a fluorescent dye at the portion to be observed when the light source of the endoscope irradiates the fluorescent dye;
• wherein a wavelength value of the first wavelength range is less than a wavelength value of the second wavelength range.