Conveyance apparatus, sample analysis system including the same, and sample preprocessing apparatus

Patent metadata

Field	Value
Publication number	US-11887780-B2
Application number	US-201917287899-A
Country	US
Kind code	B2
Filing date	Nov 7, 2019
Priority date	Dec 27, 2018
Publication date	Jan 30, 2024
Grant date	Jan 30, 2024

Abstract

The present invention comprises: an object to be conveyed that has at least one permanent magnet 10 ; a magnetic pole 25 that has a core 22 comprising a second magnetic body and a winding 21 wound around the outer periphery of the core 22 ; a drive circuit 50 for supplying a current to the winding 21 of the magnetic pole 25 ; a current detection unit 30 for detecting the value of the current flowing through the winding 21 ; and a computation unit 40 for estimating the position of the permanent magnet 10 on the basis of the current value detected by the current detection unit 30 and controlling the value of the current supplied from the drive circuit 50 to the winding 21 on the basis of information about the estimated position of the permanent magnet 10.

First claim

The invention claimed is:

1. A conveyance apparatus comprising:
a first magnetic body that is provided on a conveyance target object side;
two or more magnetic circuits, each including a core formed of a second magnetic body and a winding wound around an outer periphery of the core;
two or more drive circuits that are provided to correspond to the magnetic circuits one by one, each supplying a current to the winding;
two or more current detection units, each detecting a value of a current flowing in the winding; and
a computation unit that computes a position of the first magnetic body based on the current value detected by each of the current detection units, and controls the current supplied from each of the drive circuits to the winding on the basis of position information of the first magnetic body obtained by the computation,
wherein each of the current detection units is a resistor connected to the winding, and
the computation unit
controls the drive circuit to apply a pulse voltage having at least two or more different frequencies and detects a current from a voltage value of the resistor,
sets the pulse voltage applied to compute the position of the first magnetic body in the pulse voltage applied by the drive circuit, to be equal to or lower than a voltage used to drive the first magnetic body,
stores, in advance, a relational expression for determining a relation between a current waveform generated by the pulse voltage, and a distance, or table data for determining the relation between the current waveform and the distance, and
detects inductance from the current waveform and computes the position of the first magnetic body from any one or more of a difference in inductance between the adjacent windings, a slope of the inductance of each of the windings, and a value of the inductance.

2. The conveyance apparatus according to claim 1 , wherein the computation unit computes the position of the first magnetic body from a rising time of the current waveform.

3. The conveyance apparatus according to claim 1 , wherein the frequency of the pulse voltage having a highest frequency in the pulse voltage that is applied by the drive circuit and has the different frequencies is set to be equal to or more than five times the frequency of the pulse voltage having a lowest frequency.

4. The conveyance apparatus according to claim 1 , wherein the computation unit controls the drive circuit to apply positive and negative pulse voltages.

5. The conveyance apparatus according to claim 1 , wherein a frequency of the pulse voltage applied to compute the position of the first magnetic body in the pulse voltage applied by the drive circuit is set to be equal to or less than 10000 Hz.

6. The conveyance apparatus according to claim 5 , wherein the frequency of the pulse voltage applied to compute the position of the first magnetic body is set to be equal to or more than 100 Hz.

7. The conveyance apparatus according to claim 1 , wherein the computation unit computes the position of the first magnetic body by using the current value when the pulse voltage is applied to the windings wound around the two adjacent cores.

8. The conveyance apparatus according to claim 1 , wherein a gap between the first magnetic body and the core is equal to or less than 10 mm.

9. The conveyance apparatus according to claim 1 , wherein a number of turns of the winding is equal to or more than 100 turns.

10. The conveyance apparatus according to claim 1 , wherein the first magnetic body is a permanent magnet.

11. A sample analysis system comprising:
the conveyance apparatus according to claim 1 .

12. A sample preprocessing apparatus comprising:
the conveyance apparatus according to claim 1 .

13. The conveyance apparatus according to claim 1 , wherein the computation unit stores, in advance, any one or more of the relation between the inductance and the distance and information for determining a relation between a rising time of the current and the distance, as the relational expression, and information for determining the relation between the inductance and the distance and the information for determining the relation between the rising time of the current and the distance, as the table data.

Assignees

• Hitachi High Tech Corp

Inventors

• Aoyama Yasuaki
• Kobayashi Hiroyuki
• Kaneko Satoru
• Tamakoshi Takeshi
• Hoshi Ryosuke
• Kambara Katsuhiro
• Watanabe Hiroshi
• Onizawa Kuniaki

Classifications

• H01F7/064 Primary

  Circuit arrangements for actuating electromagnets (circuit arrangements for obtaining special operating characteristics H01F7/18; driving circuits for electromagnets making use of a switching regulator H01H47/325) · CPC title

• B65G54/02

  electrostatic, electric, or magnetic · CPC title

• G01N35/028

  having reaction cells in the form of microtitration plates · CPC title

• H01F7/02

  Permanent magnets {[PM]} · CPC title

• G01N2035/0477

  Magnetic · CPC title