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US 8,077,115 B2Granted
Antenna device, radio tag reader and article management system
AssigneeKabushiki Kaisha Toshiba
InventorsAkiko Yamada, Shuichi Sekine
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AssigneeKabushiki Kaisha Toshiba
InventorsAkiko Yamada, Shuichi Sekine
Estimating the term…
There is provided with an antenna device includes; a first antenna element which is either a spiral antenna element or a loop-like antenna element; and a first feed point provided at a first end of the first antenna element, the first end being an outer end of the spiral antenna element or an one end of the loop-like antenna element, wherein a length from an second end of the first antenna element to the first end of the first antenna element along the first antenna element is about one half wavelength of operating frequency, the second end being an inner end of the spiral antenna element or the other end of the loop-like antenna element.
An antenna device comprising:
An antenna device comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
With feed intermediate between the extremities of the antenna, e.g. centre-fed dipole: with folded element or elements, the folded parts being…
Associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a…:…
Loop antennas with a substantially uniform current distribution around the loop and
With feed to end of elongated active element, e.g. unipole: with folded element, the folded parts being spaced apart a small fraction of the…
About 3 years of term left · ends 15 Oct 2029 (estimated)
This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 2007-292121, filed on Nov. 9, 2007; the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an antenna device communicating with radio tags, a radio tag reader and an article management system. In particular, the present invention relates to an antenna device which is able, for example, to collectively read tag information from a plurality of closely located radio tags.
FIG. 1 illustrates antenna devices according to a first embodiment of the present invention;
FIG. 2 shows explanatory views illustrating an operation of the antenna devices according to the first embodiment of the present invention;
FIG. 3 illustrates an antenna device according to a second embodiment of the present invention;
With reference to the drawings, hereinafter will be described in detail some embodiments of the present invention.
FIGS. 1(A) and (B) illustrate antenna devices according to a first embodiment of the present invention.
The antenna device illustrated in FIG. 1(A) has: an antenna element (first antenna element) 101 having a wire conductor which is spirally wound with its one end (i.e. an inner end or a second end) being a base point; and a feed point (first feed point) 105 disposed at a position about one half wavelength of the operating frequency from the one end of the antenna element 101. The length of the wire conductor here corresponds to about one half wavelength of the operating frequency, and the feed point 105 is disposed at the other end (i.e. an outer end or a first end) of the spiral-like wire conductor. The example shown in FIG. 1(A) has a wire conductor which is wound into a rectangular shape. This however is only an example. The spiral antenna element may be formed by winding a wire conductor into other shapes, such as a circular shape or a triangular shape.