Optical system for a particle analyzer and particle analyzer using same

A particle analyzer, comprising:

• a flow cell through which particles pass;
• a light source configured to irradiate light to the particles passing through the flow cell;
• a photodetector configured to receive the light scattered from the particles;
• a detecting lens, which is disposed between the flow cell and the photodetector, configured to direct the light scattered from the particle toward the photodetector;
• a light shielding plate, which is disposed between the detecting lens and the photodetector, configured to block the light coming directly from the light source from entering the photodetector and having a first and a second apertures and an elongated light shielding part which is arranged between the first and second apertures;
• an irradiation optical system disposed between the light source and the flow cell;
• and
• an analyzing part configured to analyze the particles based on detection results from the photodetector.

A blood analyzer, comprising:

• a flow cell through which blood cells pass;
• a light source configured to irradiate light to the blood cells passing through the flow cell;
• a photodetector configured to receive the light scattered by the blood cells;
• a detecting lens, which is disposed between the flow cell and the photodetector, configured to direct the light scattered from the blood cell toward the photodetector;
• a light shielding plate, which is disposed between the detecting lens and the photodetector, configured to block the light coming directly from the light source from entering the photodetector and having a first and a second apertures and an elongated light shielding part which is arranged between the first and second apertures;
• an irradiation optical system disposed between the light source and the flow cell;
• and
• an analyzing part configured to analyze the blood cells based on detection results from the photodetector.