Patent Application
20140027263
The present technical field relates to a touch panel mainly used in operations of various electronic apparatuses and a method for manufacturing the touch panel.
Recently, various electronic apparatuses such as portable telephones and electronic cameras have had more advanced functions and become diversified. Electronic apparatuses including a translucent touch panel mounted to a front surface of a display device such as a liquid crystal display device have been developed. When a user operates a touch panel with a finger or the like while the user views display on a display device through the touch panel, various functions of an electronic apparatus are switched. Electronic apparatuses, which are capable of being reliably operated by a user and less expensive, have been demanded.
A plurality of belt-shaped translucent lower conductive layers 5 is formed in a direction perpendicular to upper conductive layers 2 on an upper surface of film-shaped translucent lower substrate 4. Lower conductive layer 5 is made of, for example, indium tin oxide. Each of lower electrodes 6 has one end connected to an end portion of each of lower conductive layers 5 and another end extending to the right end of the outer periphery of lower substrate 4. Lower electrode 6 is made of, for example, silver and carbon.
Upper substrate 1 is overlaid on the upper surface of lower substrate 4, and plate-shaped or film-shaped translucent cover substrate 7 is overlaid on the upper surface of upper substrate 1. They are respectively attached to each other with adhesive layers 8 and 9 including an adhesive agent as material. Thus, touch panel 10 is configured.
Touch panel 10 is disposed on a front surface of a display device such as a liquid crystal display device (not shown) and mounted to an electronic apparatus (not shown). Upper electrodes 3 extending to the right end of upper substrate 1 and lower electrodes 6 extending to the right end of lower substrate 4 are electrically coupled to an electronic circuit (not shown) of the electronic apparatus via a flexible wiring board, a connector (not shown), or the like.
In a state in which a voltage is applied between upper electrodes 3 and lower electrodes 6 from the electronic circuit, an operator carries out operations by touching an upper surface of cover substrate 7 with a finger or the like, according to display on a display device on a rear surface of touch panel 10. Then, a capacitance between upper conductive layer 2 and lower conductive layer 5 in an operated place is changed. As a result, the operated position is detected by the electronic circuit, so that various functions of the electronic apparatus are switched.
For example, when an operator touches the upper surface of cover substrate 7 over a desired menu in a state in which a plurality of menus are displayed on the display device, a part of electric charge is conducted to a finger, and a capacitance between upper conductive layer 2 and lower conductive layer 5 in a contact place of touch panel 10 is changed. The change is detected by the electronic circuit, so that a desired menu is selected.
Note here that as prior art information related to this application, for example, Japanese Patent Application Unexamined Publication No. 2011-146023 is known.
A touch panel includes a translucent substrate, a plurality of translucent lower conductive layers formed along a first direction of an upper surface of the substrate, a translucent curable insulating layer covering entire surfaces of the lower conductive layers, and a plurality of translucent upper conductive layers formed in a second direction perpendicular to the lower conductive layers and on an upper surface of the curable insulating layer.
In conventional touch panel 10, upper substrate 1 and lower substrate 4 are overlaid and attached to a lower surface of cover substrate 7. Therefore, the thickness of touch panel 10 is increased. Furthermore, a number of components of touch panel 10 is increased, thus increasing the cost.
Hereinafter, the present embodiment is described with reference to
On the upper surface of translucent substrate 11, a plurality of belt-shaped translucent lower conductive layers 12 are arranged along a predetermined direction (first direction) by a sputtering method or the like. Substrate 11 is formed of a film of polyethylene terephthalate, polyether sulfone, polycarbonate, or the like. Lower conductive layer 12 is made of indium tin oxide, tin oxide, or the like.
Each of lower electrodes 13 has one end connected to an end portion of each of lower conductive layers 12, and another end extending to an edge portion of substrate 11 (the right end in
Translucent curable insulating layer 14 is formed on the upper surface of substrate 11 by printing, adhesion, or the like, so as to cover lower electrodes 13 excluding extracted portion 30 at the right end. That is to say, curable insulating layer 14 covers the entire surfaces of lower conductive layers 12 and a part of lower electrodes 13. Curable insulating layer 14 is made of ultraviolet curable acrylate such as epoxy acrylate, urethane acrylate, imide acrylate, and polyester acrylate; thermosetting and translucent epoxy; or the like. A thickness of insulating layer 14 is suitably 5 μm or more, and 500 μm or less. Furthermore, for hardening, material to be hardened by using light and heat in combination may be used.
Belt-shaped translucent upper conductive layers 15 are formed along a direction (second direction) perpendicular to lower conductive layers 12 on the upper surface of curable insulating layer 14. A part of each of upper conductive layers 15 is embedded in curable insulating layer 14. In other words, the upper part of each of upper conductive layers 15 is not embedded in curable insulating layer 14 but exposed to the upper part of curable insulating layer 14. Upper conductive layer 15 is made of indium tin oxide, tin oxide, or the like.
Each of upper electrodes 16 has one end connected to an end portion of upper conductive layer 15, and another end extending to an edge portion of substrate 11 (the right end in
Note here that upper electrodes 16 and lower electrodes 13 are formed by pattern printing or by forming a conductive thin film by deposition or sputtering, followed by masking a predetermined pattern so as to dissolve and remove unnecessary portions.
Translucent cover layer 17 covers the upper surface of curable insulating layer 14 excluding extracted portion 32 at the right end of upper electrodes 16. That is to say, seen from the upper surface, an area of curable insulating layer 14 is larger than that of cover layer 17, and an area of substrate 11 is larger than that of curable insulating layer 14. Cover layer 17 is formed of material such as acrylate and epoxy by printing or the like. Cover layer 17 is brought into contact with the upper parts of upper conductive layers 15. As mentioned above, touch panel 100 is configured.
Then, patterns of upper conductive layers 15 are masked with an insulating resin film such as a dry film resist on the lower surface of conductive thin film 21, which are immersed in a predetermined etchant for dissolving and removing conductive thin film 21 in unnecessary places. As a result, as shown in
Next, as shown in
Thereafter, base material 20 is peeled off, and then upper conductive layers 15 and curable insulating layer 14 are transferred to the upper surface of lower conductive layer 12 as shown in
Then, touch panel 100 is disposed on the front surface of a display device (not shown) such as a liquid crystal display device and mounted to an electronic apparatus (not shown). Extracted portions 30 of lower electrodes 13, which extend to the right end of substrate 11, and extracted portions 32 of upper electrodes 16, which extend to the right end of curable insulating layer 14, are electrically coupled to an electronic circuit (not shown) of the electronic apparatus via a flexible wiring board, a connector, or the like (not shown).
An operator carries out operations by touching an upper surface of cover substrate 17 with a finger or the like, according to display on a display device on a rear surface of touch panel 100 in a state in which a voltage is applied between upper electrodes 13 and lower electrodes 16 from the electronic circuit. Then, a capacitance between lower conductive layer 12 and upper conductive layer 15 in an operated place is changed. As a result, the operated place is detected by the electronic circuit, so that various functions of the electronic apparatus are switched.
For example, when an operator touches the upper surface of cover layer 17 with a finger on a desired menu in a state in which a plurality of menus are displayed on the display device, a part of electric charge is conducted to the finger, and a capacitance between upper conductive layer 12 and lower conductive layer 15 in an operated place of touch panel 100 is changed. The change is detected by the electronic circuit, so that a desired menu is selected.
In the present embodiment, lower conductive layers 12 and upper conductive layers 15 are provided with curable insulating layer 14 interposed therebetween on the upper surface of one substrate 11. Therefore, a plurality of substrates is not required to be used, and a number of components can be reduced. Furthermore, the substrates are not required to be overlaid and attached to each other. Thus, it is possible to produce touch panel 100 which can be assembled easily and which is less expensive.
Furthermore, curable insulating layer 14 is provided between upper conductive layers 15 and lower conductive layers 12, and thereby upper conductive layers 15 and lower conductive layers 12 are insulated from each other reliably. Therefore, an operation position can be reliably detected. Curable insulating layer 14 is excellent in terms of stability with respect to environmental change because it absorbs water less easily as compared with adhesive agents.
Note here that a configuration is described in which lower conductive layers 12 and upper conductive layers 15 are formed in a belt shape with a predetermined width. However, a conductive layer obtained by connecting a plurality of rectangular portions in a belt shape may be used. Then, a plurality of rectangular gap portions may be provided in the belt-shaped conductive layers. That is to say, a configuration may be employed in which lower conductive layers 12 and upper conductive layers 15 are formed with curable insulating layer 14 interposed therebetween such that rectangular portions and gap portions are alternately overlapped onto each other.
Furthermore, in the present embodiment, lower conductive layers 12 and upper conductive layers 15 are formed of a metal thin film of indium tin oxide, tin oxide, or the like, by a sputtering method or the like. However, they may be formed by dispersing thin lines of metal such as silver, or thin lines of carbon or the like, in translucent resin such as acrylic resin. Alternatively, they may be formed of translucent conductive resin such as polythiophene and polyaniline.
A touch panel in accordance with the present embodiment includes a small number of components and is less expensive. Furthermore, the touch panel has an advantageous effect that an operation can be carried out reliably, and is useful as an input device of various electronic apparatuses.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-166771 | Jul 2012 | JP | national |
