Optically transparent conductive material

Abstract

Provided is an optically transparent conductive material which is suitable as an optically transparent electrode for capacitive touchscreens, the optically transparent conductive material not causing moire even when placed over a liquid crystal display, having a favorably low pattern conspicuousness (non-conspicuousness), and having a high reliability. The optically transparent conductive material has, on an optically transparent support, an optically transparent conductive layer having optically transparent sensor parts electrically connected to terminal parts and optically transparent dummy parts not electrically connected to terminal parts, and in this optically transparent conductive material, the sensor parts and the dummy parts are formed of a metal thin line pattern having a mesh shape, and in the plane of the optically transparent conductive layer, the contour shape of each of the sensor parts extends in a first direction, the dummy parts are arranged alternately with the sensor parts in a second direction perpendicular to the first direction, the sensor parts are arranged at a cycle of L in the second direction, at least part of the metal thin line pattern in the sensor parts has a cycle of 2L / N in the second direction (wherein N is any natural number), and the metal thin line pattern in the dummy parts has a cycle longer than 2L / N or does not have a cycle in the second direction.

Description

TECHNICAL FIELD[0001]The present invention relates to an optically transparent conductive material mainly used for touchscreens and, in particular, to an optically transparent conductive material preferably used for optically transparent electrodes of projected capacitive touchscreens.BACKGROUND ART[0002]In electronic devices, such as personal digital assistants (PDAs), laptop computers, office automation equipment, medical equipment, and car navigation systems, touchscreens are widely used as their display screens that also serve as input means.[0003]There are a variety of touchscreens that utilize different position detection technologies, such as optical, ultrasonic, surface capacitive, projected capacitive, and resistive technologies. A resistive touchscreen has a configuration in which an optically transparent conductive material and a glass plate with an optically transparent conductive layer are separated by spacers and face each other so as to function as a touchsensor forme...

AI Technical Summary

Benefits of technology

The invention provides an optically transparent material that can act as an electrode for capacitive touchscreens. This material is not likely to cause any issues when used on liquid crystal displays and is highly reliable. It is also visually non-conspicuous, meaning it is not easily noticeable to the naked eye.

Problems solved by technology

However, there has been a problem of low optical transparency due to high refractive index and high surface light reflectivity of ITO conductive films.

Another problem is that ITO conductive films have low flexibility and thus are prone to crack when bent, resulting in increased electric resistance of the optically transparent conductive material.

When an optically transparent conductive material having, on an optically transparent support, such a metal thin line pattern as described above is placed over a liquid crystal display, the cycle of the metal thin line pattern and the cycle of the liquid crystal display element interfere with each other, causing a problem of moire.

In recent years, liquid crystal displays of different resolutions have been used, which further complicates the above-mentioned problem.

Images