In-fluid floating substance measurement flow cell and particle counter
Inventors
Matsuda, Tomonobu • Minakami, Takashi • Sakaue, Daisuke • Shinozaki, Daisuke
Assignees
Publication Number
US-11009445-B2
Publication Date
2021-05-18
Expiration Date
2040-01-22
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Abstract
An in-fluid floating substance measurement flow cell includes: a main body having at least a predetermined portion made of a material having translucency; and a flow passage formed inside the main body, having both end openings at an outer surface of the main body in a substantially identical direction, and configured such that fluid flows in the flow passage. The flow passage has a predetermined section arranged between two opposing flat wall surfaces facing each other, and the predetermined portion includes the predetermined section.
Core Innovation
The invention provides an in-fluid floating substance measurement flow cell comprising a main body with at least a predetermined portion made of a translucent material, and a flow passage inside the main body. Both end openings of the flow passage are formed at an outer surface of the main body in a substantially identical direction, allowing fluid to flow through the passage. The flow passage includes a predetermined section arranged between two opposing flat wall surfaces facing each other, and this predetermined portion includes the predetermined section.
The problem addressed by the invention is that in conventional measurement devices with multiple flow cells, pipes connected to the flow cells are moved or warped during measurement, causing fine particles to be generated from inner walls of the pipes, which act as noise sources in the detection of particles in the sample liquid. This leads to degraded accuracy in particle detection. Additionally, in devices with a single flow cell, the pipes also move depending on their connection form, similarly degrading detection accuracy.
The invention solves this problem by forming both end openings of the flow passage on the same outer surface and direction, enabling pipes connected to the flow cell to be easily stabilized in certain positions without interfering with the irradiation light used for particle detection. This arrangement prevents noise caused by pipe movement and improves measurement accuracy. Further, the flow passage includes flat opposing wall surfaces in the detection region, reducing diffuse reflection and associated noise at the interface between the wall surfaces and the fluid, thereby further improving measurement accuracy.
Claims Coverage
The patent includes fourteen inventive features derived from independent claims related to both an in-fluid floating substance measurement flow cell and a particle counter employing the flow cell.
Flow cell with translucency and flow passage openings in the same direction
An in-fluid floating substance measurement flow cell having a main body with at least a translucent portion and a flow passage formed inside with both end openings at an outer surface of the main body in a substantially identical direction, where the flow passage has a predetermined section arranged between two opposing flat wall surfaces facing each other included in the predetermined translucent portion.
Flow passage structure with introduction, discharge, and relay flow passages
A flow passage including an inlet port and an outlet port both serving as end openings, comprising an introduction flow passage extending from the inlet port in a predetermined direction, a discharge flow passage extending parallel in the same direction from the outlet port, and a relay flow passage extending perpendicular to the predetermined direction connecting end portions of the introduction and discharge flow passages, with two flat wall surfaces facing each other at a portion of the introduction flow passage in the relay flow passage direction.
Condensing member for light condensation at introduction flow passage extension
A condensing member is provided at a portion of the main body corresponding to a virtual extension position of the introduction flow passage in the fluid supply direction, having an optical axis such that light is condensable in the direction the fluid is supplied.
Particle counter with flow cell, light source, irradiation optical system, and light receiving system receiving condensed emitted light
A particle counter comprising the in-fluid floating substance measurement flow cell, a light source emitting irradiation light, an irradiation optical system irradiating the predetermined section of the flow passage through the two wall surfaces, and a light receiving optical system receiving emitted light generated from particles passing through the detection region formed in the flow passage, where the light receiving system receives emitted light condensed by the condensing member.
Particle counter with multi-flow cell having multiple flow cells arrayed in a third direction fixed to the main body
A particle counter including the flow cell and optical systems as above and further including a multi-flow cell formed by multiple in-fluid floating substance measurement flow cells arrayed in a third direction perpendicular to the introduction flow passage direction and the relay flow passage direction, with flow passages arrayed, fixed at a position relative to the main body of the particle counter.
Optical axis moving unit for moving irradiation and emitted light optical axes along array
An optical axis moving unit configured to move, along the array of multiple flow passages, the optical axis of the irradiation light entering the flow passage and the optical axis of the emitted light received by the light receiving optical system in the third direction.
Focal point adjustment unit for adjusting light receiving optical system focal point
A focal point adjustment unit configured to adjust the focal point of the light receiving optical system in the first direction.
Storage and control of optical axis positions for multiple flow passages
A storage storing in advance the position in the third direction of each optical axis moved corresponding to each flow passage position, with the optical axis moving unit configured to move each optical axis to the stored position corresponding to the detection region's flow passage.
Actuators for moving light receiving system and associated components
The focal point adjustment unit includes an actuator moving a stage supporting the light receiving optical system in the first direction, and the optical axis moving unit includes another actuator moving a stage supporting that actuator together with the irradiation optical system in the third direction.
Storage for optical axis and focal point adjustment positions and corresponding movement control
In addition to storing optical axis positions in the third direction, the storage stores focal point positions in the first direction, and the focal point adjustment unit adjusts the focal point to stored positions corresponding to the detection region's flow passage.
Fixed close contact of each flow cell with a reference portion in the multi-flow cell
Each in-fluid floating substance measurement flow cell in the multi-flow cell is fixed in close contact with a reference portion defining the position of the whole multi-flow cell.
Elastic member pressing flow cells to achieve close contact with position reference
The multi-flow cell includes an elastic member configured to press each flow cell so as to cause close contact with the reference position portion.
Detection region formed in the predetermined section of the flow passage
The flow cell includes a detection region of a floating substance contained in the fluid formed in the predetermined section of the flow passage.
Particle counter with irradiation light angle control to avoid passing other flow passage sections
An irradiation optical system causes irradiation light to enter the flow cell at an angle such that the center of a beam bundle passes through the two wall surfaces of the predetermined section without passing through other sections of the flow passage.
The patent claims cover an in-fluid floating substance measurement flow cell with a specific flow passage structure having translucency, flat opposing walls, and both openings on the same surface, and particle counters incorporating this flow cell with configurations including condensing members, multi-flow cells arrayed in a third direction, optical axis moving units, focal point adjustment, and precise positioning and fixing of flow cells, all contributing to improved particle detection accuracy.
Stated Advantages
Occurrence of noise due to pipe movement can be reduced, thereby improving accuracy of particle detection and particle counting.
The scattered light generated from particles can be effectively condensed close to the detection region, enhancing measurement accuracy.
Irradiation light passes only through the predetermined flow passage section, minimizing noise from interference with other flow passage sections and enabling easier detection of scattered light.
Adjustment of optical axes and focal points corresponding to the selected flow cell can be performed with high accuracy automatically, improving detection precision.
The flow cells are firmly fixed in accurate positions within the flow cell holder, reducing degradation in detection accuracy due to positional shifts.
Movable optical components are collectively moved via actuators, improving efficiency in optical axis movement and focus adjustment.
All pipes connected to flow cells are aligned on one surface, contributing to downsizing of the particle counter and reducing pipe-related noise sources.
Documented Applications
Measurement and detection of particles floating in fluid samples using a particle counter.
Particle counting in samples where scattered light or fluorescence emitted from particles is analyzed.
Use in multi-channel particle counters employing multiple flow cells arrayed for simultaneous or sequential measurement.
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