Microparticle measuring apparatus

Patent metadata

Field	Value
Publication number	US-9429508-B2
Application number	US-201314434404-A
Country	US
Kind code	B2
Filing date	Aug 30, 2013
Priority date	Oct 15, 2012
Publication date	Aug 30, 2016
Grant date	Aug 30, 2016

Abstract

A microparticle measuring apparatus for highly accurately detecting the position of a microparticle flowing through a flow channel includes a light irradiation unit for irradiating a microparticle flowing through a flow channel with light, and a scattered light detection unit for detecting scattered light from the microparticle, including an objective lens for collecting light from the microparticle, a light splitting element for dividing the scattered light from the light collected by the objective lens, into first and second scattered light, a first scattered light detector for receiving an S-polarized light component, and an astigmatic element disposed between the light splitting element and the first scattered light detector, and making the first scattered light astigmatic. A relationship between a length L from a rear principal point of the objective lens to a front principal point of the astigmatic element, and a focal length f of the astigmatic element satisfies the following formula I.

1.5 f ≦L≦2.5 f   (I)

First claim

The invention claimed is:

1. A microparticle measuring apparatus comprising:
a light irradiation unit configured to irradiate a microparticle flowing through a flow channel with light; and
a scattered light detection unit configured to detect scattered light from the microparticle,
the scattered light detection unit at least including:
an objective lens configured to collect light emitted from the microparticle;
a light splitting element configured to divide the scattered light from the light having been collected by the objective lens, into first scattered light and second scattered light;
a first scattered light detector configured to receive the first scattered light; and
an astigmatic element disposed between the light splitting element and the first scattered light detector, the astigmatic element configured to make the first scattered light astigmatic, wherein

a relationship between a length L from a rear principal point of the objective lens to a front principal point of the astigmatic element, and a focal length f of the astigmatic element satisfies the following formula (I)
1.5 f≦L≦ 2.5 f   (I).

2. The microparticle measuring apparatus according to claim 1 , wherein the light splitting element is a polarization element configured to diffracting the scattered light into an S-polarized light component and a P-polarized light component, and the first scattered light is the S-polarized light component.

3. The microparticle measuring apparatus according to claim 1 , wherein the astigmatic element is a cylindrical lens.

4. The microparticle measuring apparatus according to claim 3 , wherein when a light input direction to the microparticle is defined as the z-direction, a flowing direction of the microparticle is defined as the x-direction, and a direction perpendicular to the z- and x-directions is defined as the y-direction, the astigmatic element is disposed on a plane perpendicular to a y-direction to have an angle 0° to 5° between a generatrix of the astigmatic element and a line extending in an x-direction or a line extending in a z-direction.

5. The microparticle measuring apparatus according to claim 1 , wherein the first scattered light detector is a detector having a light receiving surface divided into a plurality of areas.

6. The microparticle measuring apparatus according to claim 5 , wherein the first scattered light detector is a quadrant photodiode.

7. The microparticle measuring apparatus according to claim 6 , wherein when the light input direction to the microparticle is defined as the z-direction, the flowing direction of the microparticle is defined as the x-direction, and the direction perpendicular to the z- and x-directions is defined as the y-direction, the first scattered light detector is disposed on a plane perpendicular to the y-direction to have an angle of 40° to 50° between a dividing line of the first scattered light detector and a line extending in the x-direction or a line extending in the z-direction.

8. The microparticle measuring apparatus according to claim 1 , wherein a flowing position of the microparticle is detected based on the change in light receiving position of the first scattered light.

9. The microparticle measuring apparatus according to claim 8 , wherein
the light receiving surface of the first scattered light detector is divided into a lattice shape to have a first area, a second area, a third area, and a fourth area, and
the first scattered light detector acquires the positional information of the microparticle based on a difference (A-C) between a detection value A of the first area and a detection value C of the third area not adjacent to the first area.

10. The microparticle measuring apparatus according to claim 8 , wherein
the light receiving surface of the first scattered light detector is divided into a lattice shape to have a first area, a second area, a third area, and a fourth area, and
the first scattered light detector acquires the positional information of the microparticle based on a difference ((A+C)−(B+D)) between the sum (A+C) of the detection value A of the first area and the detection value C of the third area not adjacent to the first area, and the sum (B+D) of a detection value B of the second area adjacent to the first area and a detection value D of the fourth area not adjacent to the second area.

11. The microparticle measuring apparatus according to claim 1 , wherein the light irradiation unit irradiates the microparticle flowing through an analysis chip including a microchannel, with light.

Assignees

• Sony Corp

Inventors

• Takeuchi Taichi
• Imanishi Shingo

Classifications

• G01N15/1434 Primary

  Optical arrangements · CPC title

• G01N21/53

  within a flowing fluid, e.g. smoke · CPC title

• G01N15/1436 Primary

  the optical arrangement forming an integrated apparatus with the sample container, e.g. a flow cell · CPC title

• G01N21/49

  within a body or fluid · CPC title

• G01N2015/1006

  for cytology · CPC title