Conductive film and touch panel including the same

Patent metadata

Field	Value
Publication number	US-10001891-B2
Application number	US-201615260328-A
Country	US
Kind code	B2
Filing date	Sep 9, 2016
Priority date	Mar 23, 2016
Publication date	Jun 19, 2018
Grant date	Jun 19, 2018

Abstract

An object of the present disclosure is to improve visibility while suppressing an impedance of an antenna pattern formed on a conductive film. In a film base material on which an antenna pattern for near field communication is formed, the antenna pattern is formed of a metal having excellent conductivity. The antenna pattern is formed into a loop line shape with three to five turns and has a length of 200 to 500 mm, an interval between adjacent loop lines of 200 to 400 μm, and a line width of 4 to 20 μm. The thickness of the antenna pattern is set to a value calculated by the following Formula (1) so that the impedance at a maximum load becomes equal to or less than 50Ω.

Thickness=Specific Resistance×Length/(Impedance×Width)   Formula (1)

First claim

What is claimed is:

1. A plurality of conductive films each comprising:
a transparent first film base material; and
an antenna pattern for near field communication formed of a metal having excellent conductivity on one surface of the transparent first film base material, the antenna pattern having a first end and a second end located at an edge of the transparent first film base material, the antenna pattern being formed as a plurality of linear loops surrounding a vacant area on the transparent first film base material so that the vacant area is located at a center of the antenna pattern, wherein
a total length of the plurality of linear loops of the antenna pattern is 200 to 500 mm, a spacing between adjacent ones of the plurality of linear loops is 200 to 400 ; μm, and a line width of the plurality of linear loops is 4 to 20 μm,
the plurality of conductive films are stacked in such a manner that the antenna patterns together form a vertically-stacked antenna with each respective antenna pattern vertically matching each other,
a thickness of each antenna pattern is such that an impedance of the vertically-stacked antenna at a maximum load is equal to or less than 50 Q, and
the vertically-stacked antenna is configured opposite an electrode pattern formed on another conductive film for detecting a touch position, the electrode pattern comprising a first electrode pattern for detecting an X-direction of the touch position formed on a first side of the another conductive film, and a second electrode pattern for detecting a Y-direction of the touch position formed on a second side of the another conductive film.

2. The conductive film according to claim 1 , wherein each loop line of the plurality of linear loops of the antenna pattern is formed into one of a square, a triangle, and a circle.

3. A touch panel comprising a conductive film according to claim 1 , wherein
a cover panel is superimposed on one of the first and second sides of the another conductive film.

4. A touch panel comprising a conductive film according to claim 1 , further comprising
the another conductive film is superimposed opposite to a surface on which a closest antenna pattern is formed, and
a cover panel is further superimposed on the another conductive film.

Assignees

• Smk Kk

Inventors

• Ikeda Ryuji
• Nagumo Masayuki
• Okamura Ryo
• MIZUMOTO Kensaku

Classifications

• G06F3/046

  by electromagnetic means · CPC title

• G06F3/044 Primary

  by capacitive means · CPC title

• B32B3/10

  characterised by a discontinuous layer, i.e. formed of separate pieces of material · CPC title

• B32B15/20

  comprising aluminium or copper {(B32B15/016 and B32B15/017 take precedence)} · CPC title

• G06K19/07758

  arrangements for adhering the record carrier to further objects or living beings, functioning as an identification tag · CPC title