Touch panel and method of detecting position

• US 9,590,623 B2
• Filed: 08/12/2014
• Issued: 03/07/2017
• Est. Priority Date: 02/15/2012
• Status: Active Grant

• Current Assignee: Fujitsu Component Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Component Limited (Fujitsu Limited)
• Inventors: Sekizawa, Mitsuhiro, Sakurai, Satoshi, Shimizu, Nobuyoshi, Kurashima, Shigemi
• Primary Examiner(s): Luebke, Renee
• Assistant Examiner(s): SAEED, AHMED M
• Application Number:
  US14/457,164
• Publication Number:
  US 20140346029A1
• Time in Patent Office: 938 Days
• Field of Search: 200/600
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 17/9647 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2017/9615 using three electrodes per touch switch
• CPC Class Codes: H03K 2217/960755 Constructional details of capacitive touch and proximity switches

Abstract

A touch panel includes a first conductive film having separate areas, each of which has a strip shape with a length direction thereof extending in a first direction, a second conductive film having separate areas, each of which has a strip shape with a length direction thereof extending in a second direction substantially perpendicular to the first direction, and a third conductive film, wherein the separate areas of the first conductive film are arranged side by side in the second direction, and the separate areas of the second conductive film are arranged side by side in the first direction, wherein position detection based on a capacitive method is performed by using the first conductive film and the second conductive film, and wherein a potential of a position of contact between the second conductive film and the third conductive film is detected to detect the position of the contact.

Claims

1. A touch panel, comprising:

a first substrate having first conductive films formed thereon, each of which has a strip shape with a length direction thereof extending in a first direction and has an electrode at one end thereof in the first direction;

a second substrate having second conductive films formed thereon, each of which has a strip shape with a length direction thereof extending in a second direction perpendicular to the first direction, and has electrodes at opposite ends thereof in the second direction; and

a third substrate having a third conductive film of a planar shape formed thereon,

wherein the first substrate, the second substrate, and the third substrate are stacked one over another in the order named,

wherein only every other one of the second conductive films are driven when performing position detection by use of the first conductive film and the second conductive film, and wherein all of the second conductive films are driven when performing position detection by use of the second conductive film and the third conductive film.

2. A touch panel, comprising:

a first conductive film having a plurality of separate areas, each of which has a strip shape with a length direction thereof extending in a first direction; and

a second conductive film having a plurality of separate areas, each of which has a strip shape with a length direction thereof extending in a second direction substantially perpendicular to the first direction,

wherein the separate areas of the first conductive film are arranged side by side in the second direction, and the separate areas of the second conductive film are arranged side by side in the first direction,

wherein position detection based on a capacitive method is performed by using the first conductive film and the second conductive film,

wherein position detection based on a resistive method is performed by detecting a potential of a position of contact between the first conductive film and the second conductive film, and

wherein only some but not all of the separate areas of the first conductive film are connected to a current detecting unit, and each of the separate areas of the first conductive film is connected to a potential detecting unit.

3. The touch panel as claimed in claim 2, wherein the first conductive film is formed on one surface of a first transparent substrate, and the second conductive film is formed on one surface of a second transparent substrate, and wherein the one surface of the first transparent substrate and the one surface of the second transparent substrate face each other.

4. The touch panel as claimed in claim 2, wherein only some but not all of the separate areas of the second conductive film are connected to a current detecting unit, and each of the separate areas of the second conductive film is connected to a potential detecting unit.

5. The touch panel as claimed in claim 4, wherein each of the separate areas of the second conductive film is connected to a switch configured to generate a potential gradient in each of the separate areas of the second conductive film in the second direction.

6. The touch panel as claimed in claim 2, wherein each of the separate areas of the first conductive film is connected to a switch configured to generate a potential gradient in each of the separate areas of the first conductive film in the first direction.

7. A touch panel, comprising:

a first conductive film having a plurality of separate areas, each of which has a strip shape with a length direction thereof extending in a first direction;

a second conductive film having a plurality of separate areas, each of which has a strip shape with a length direction thereof extending in a second direction substantially perpendicular to the first direction; and

a third conductive film,

wherein the separate areas of the first conductive film are arranged side by side in the second direction, and the separate areas of the second conductive film are arranged side by side in the first direction,

wherein position detection based on a capacitive method is performed by using the first conductive film and the second conductive film,

wherein position detection based on a resistive method is performed by detecting a potential of a position of contact between the second conductive film and the third conductive film,

wherein each of the separate areas of the first conductive film is connected to a current detecting unit, wherein only some but not all of the separate areas of the second conductive film are connected to a current detecting unit, and each of the separate areas of the second conductive film is connected to a potential detecting unit, and wherein the third conductive film is connected to a potential detecting unit.

8. The touch panel as claimed in claim 7, wherein each of the separate areas of the second conductive film is connected to a switch configured to generate a potential gradient in each of the separate areas of the second conductive film in the second direction, and the third conductive film is connected to a switch configured to generate a potential gradient in the third conductive film in the first direction.

9. The touch panel as claimed in claim 7, wherein the second conductive film is formed on one surface of a second transparent substrate, and the third conductive film is formed on one surface of a third transparent substrate, and wherein the one surface of the second transparent substrate and the one surface of the third transparent substrate face each other.

10. The touch panel as claimed in claim 9, wherein the third transparent substrate has a fourth conductive film formed on another surface thereof.

11. The touch panel as claimed in claim 7, wherein gaps between the separate areas of the second conductive film are narrower than gaps between the separate areas of the first conductive film.