Flow cell and particle measuring device
Inventors
Yaguchi, Hiroaki • Yamakawa, Yuki • SHIMMURA, Masaki • Matsuda, Tomonobu
Assignees
Publication Number
US-11268894-B2
Publication Date
2022-03-08
Expiration Date
2040-12-24
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Abstract
A flow cell includes a body and a flow channel. The body is formed out of blocks made of an uniaxial crystal material and joined to one another. The flow channel is formed inside the body, so that the flow cell is configured to be used to measure particles passing through the flow channel based on reception of scattered light generated from the particles. A crystallographic c-axis in a predetermined part of the body is configured to being substantially perpendicular to both a receiving direction and a polarization direction of the scattered light.
Core Innovation
The invention relates to a flow cell formed from blocks of an uniaxial crystal material joined together, with a flow channel inside for measuring particles passing through based on scattered light reception. A key feature is that the crystallographic c-axis in a predetermined part of the body is configured to be substantially perpendicular to both the receiving direction and the polarization direction of the scattered light. This arrangement suppresses the generation of extraordinary light caused by birefringence when scattered light passes through the flow cell's crystalline material.
The problem addressed is that in particle measuring devices using crystalline flow cells, birefringence causes astigmatism, spot size increase, and phase rotation in the extraordinary light component of scattered light. In conventional designs where the flow channel is oriented along the c-axis, the polarization direction of scattered light coincides with the c-axis, resulting in extraordinary light which degrades light condensing performance and the signal-to-noise ratio for particle measurement.
The invention solves this problem by orienting the c-axis perpendicularly to both the scattered light receiving direction and polarization direction, so that the scattered light transmitted through the predetermined part of the cell serves as ordinary light. This configuration reduces the astigmatism and phase distortion caused by birefringence, enhancing measurement accuracy and signal quality with standard light receiving systems as well as interference systems.
Claims Coverage
The patent includes two independent claims covering the flow cell and the particle measuring device, with four main inventive features detailed.
Flow cell with c-axis orientation perpendicular to scattered light directions
A flow cell comprising a body formed from blocks made of an uniaxial crystal material joined together, with a flow channel inside configured to measure particles based on scattered light, wherein the crystallographic c-axis in a predetermined part of the body is substantially perpendicular to both the receiving direction and polarization direction of the scattered light.
Consistency of crystallographic c-axis directions across the body
The flow cell in which the direction of the crystallographic c-axis in the predetermined part of the body and the direction of the crystallographic c-axis in another part of the body are substantially the same.
Joining method of the body blocks
The flow cell body is formed by joining a crystal face of one type in one of the blocks to a crystal face of the same type in another block.
Particle measuring device with specific flow cell orientation
A particle measuring device comprising the flow cell, a light source emitting irradiation light, an irradiation optical system transmitting light through another part of the flow cell to irradiate a sample in the flow channel, a condensing optical system condensing scattered light transmitted through the predetermined part, light receiving elements detecting this scattered light, and a measurement system to measure particles based on the detection signal, wherein the flow cell is disposed so that the crystallographic c-axis in the predetermined part is perpendicular to both receiving direction and polarization direction of the scattered light.
These inventive features collectively provide a flow cell and particle measuring device configuration that reduces birefringence-induced extraordinary light by orienting the c-axis perpendicular to both receiving and polarization directions of scattered light, and specify the structural configuration and assembly method of the flow cell blocks to achieve the desired orientation and measurement performance.
Stated Advantages
Extraordinary light caused by birefringence can be suppressed by orienting the crystallographic c-axis perpendicular to both the scattered light receiving direction and polarization direction.
Reduction of astigmatism, spot size increase, and phase rotation leads to improved light condensing performance and signal-to-noise ratio in particle measurement.
Enhanced interference between scattered light and reference light in interference optical systems increases the intensity of output signals and improves measurement accuracy.
Documented Applications
Measuring particles contained in a sample fluid by detecting scattered light generated from the particles as they pass through a flow channel within the flow cell.
Use in particle measuring devices that irradiate sample fluids with light and detect scattered light using interference optical systems or non-interference optical systems.
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