Storage medium location detection system and program

• US 10,295,661 B2
• Filed: 09/23/2016
• Issued: 05/21/2019
• Est. Priority Date: 10/16/2015
• Status: Active Grant

• Current Assignee: RFLocus, Inc.
• Original Assignee: RFLocus, Inc.
• Inventors: Kamiya, Hajime
• Primary Examiner(s): Gregory, Bernarr E
• Application Number:
  US15/534,364
• Publication Number:
  US 20180003812A1
• Time in Patent Office: 970 Days
• CPC Class Codes: G01S 13/32 using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
• CPC Class Codes: G01S 13/346 using noise modulation
• CPC Class Codes: G01S 13/46 Indirect determination of position data
• CPC Class Codes: G01S 13/84 for distance determination by phase measurement
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 2013/466 by Trilateration, i.e. two antennas or two sensors determine separately the distance to a target, whereby with the knowledge of the baseline length, i.e. the distance between the antennas or sensors, the position data of the target is determined
• CPC Class Codes: G06K 7/10 by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation

Abstract

A storage medium-compatible communications unit, a phase detection unit, a parameter acquisition section and a location detection section are provided. The storage medium-compatible communications unit communicates with a storage medium by wireless using electromagnetic waves at a predetermined frequency. The phase detection unit detects phases of signals received from the storage medium. The parameter acquisition section acquires a distance detection parameter to be used in detecting a storage medium distance from a first position of an antenna to the storage medium. The first position is a position in a range of positions of the antenna from which the distance to the storage medium is shortest. The distance detection parameter is a value set in accordance with a positional relationship between the first position and a second position. The second position is a position of the antenna in the range of positions of the antenna that is different from the first position. The location detection section detects the storage medium distance, using a first phase detected by the phase detection unit at the first position, a second phase detected by the phase detection unit at the second position, and the distance detection parameter acquired by the parameter acquisition section. The location detection section identifies the first position at a time at which a trend of changes of phase detected by the phase detection unit in association with movement of the antenna reverses.

Claims

1. A storage medium location detection system comprising:

an antenna;

a storage medium-compatible communications unit that communicates through the antenna with a storage medium by wireless using electromagnetic waves at a predetermined frequency;

a phase detection unit that detects phases of signals received from the storage medium; and

a controller that is configured to function as a parameter acquisition part and a location detection part, wherein

the parameter acquisition part configured to acquire a distance detection parameter, the distance detection parameter being a predetermined value set in accordance with a positional relationship between a first position of the antenna and a second position of the antenna that is different from the first position, each of the first position and the second position being a position of the antenna in a range of positions of the antenna, and a distance from the first position to the storage medium being shortest; and

the location detection part configured to detect a storage medium distance from the first position to the storage medium, the location detection part using a first phase detected by the phase detection unit at the first position, a second phase detected by the phase detection unit at the second position, and the distance detection parameter acquired by the parameter acquisition part,

wherein the location detection part identifies the first position at a time at which a trend of changes of phase detected by the phase detection unit in association with movement of the antenna reverses.

2. The storage medium location detection system according to claim 1, wherein if a right-angled triangle is formed with vertices at locations of the storage medium, the first position and the second position, an angle that corresponds to the first position being a right angle, the parameter acquisition part acquires the distance between the first position and the second position.

3. The storage medium location detection system according to claim 1, wherein the first position and the second position are disposed on a same line of a circumference, and the distance detection parameter that the parameter acquisition part acquires includes a radius of the circumference and a central angle of an arc of the circumference whose two ends are the first position and the second position.

4. The storage medium location detection system according to claim 1, wherein the location detection part detects a storage medium bearing measured from the first position on which the storage medium is disposed, the storage medium bearing being a direction of the antenna that is detected at a time at which the first position is identified.

5. The storage medium location detection system according to claim 4, wherein the location detection part detects a storage medium bearing and a storage medium distance corresponding to a horizontal direction, and the location detection part detects a storage medium bearing and a storage medium distance corresponding to a vertical direction.

6. The storage medium location detection system according to claim 4, wherein the controller is further configured to function as an output part that outputs by displaying the storage medium distance and the storage medium bearing detected by the location detection part.

7. The storage medium location detection system according to claim 6, wherein the output part outputs by displaying the storage medium bearing and the storage medium distance corresponding to the horizontal direction and the storage medium bearing and the storage medium distance corresponding to the vertical direction that are detected by the location detection part.