CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY

This application claims priority to Korean Patent Application No. 10-2017-0105952 filed on Aug. 22, 2017 in the Korean Intellectual Property Office (KIPO), the entire disclosure of which is incorporated by reference herein.

BACKGROUND

1. Field

The present invention relates to a touch sensor and an image display device including the same. More particularly, the present invention relates to a touch sensor including a patterned sensing electrode, and an image display device including the same.

2. Description of the Related Art

As information technologies are being developed, various demands in display devices having thinner dimension, light-weight, high efficiency in power consumption, etc., are increasing. The display device may include a flat panel display device such as a liquid crystal display (LCD) device, a plasma display panel (PDP) device, an electro-luminescent display device, an organic light emitting diode (OLED) display device, etc.

A touch panel or a touch sensor capable of inputting a user's direction by selecting an instruction displayed on a screen with a finger or an inputting tool is also developed. The touch panel or the touch sensor may be combined with the display device so that display and information input functions may be implemented in one electronic device.

As a resolution of the display device become increased to a QHD (Quad High Definition) level or a UHD (Ultra High Definition) level, a high resolution is also required in the touch sensor. Thus, a reduction of an optical interference from a sensing electrode included in the touch sensor is needed.

For example, if conductive patterns included in the sensing electrode are visible to the user, an image quality of the display device may be degraded. When structures included in a display panel of the display device overlap the conductive patterns of the sensing electrode, the image quality may be further degraded.

Thus, development of the touch sensor having improved transmittance and optical properties while also having high sensitivity is required. For example, Korean Patent Publication No. 2014-0092366 discloses an image display device combined with a touch screen panel including a touch sensor. However, demands of a touch sensor or a touch panel with high resolution and improved optical properties are still increasing.

SUMMARY

According to an aspect of the present invention, there is provided a touch sensor having improved sensitivity, resolution and optical properties.

According to an aspect of the present invention, there is provided an image display device including the touch sensor and having enhanced image quality.

The above aspects of the present inventive concepts will be achieved by the following features or constructions:

(1) A touch sensor, comprising: a substrate layer; a plurality of sensing electrodes on the substrate layer; and a dummy line between the sensing electrodes, the dummy line extending along a boundary of the sensing electrode.

(2) The touch sensor according to the above (1), wherein the boundary of the sensing electrode has a wavy shape or a saw-tooth shape, and the dummy line has a wave form the same as that of the boundary of the sensing electrode.

(3) The touch sensor according to the above (1), wherein the sensing electrodes are arranged along a first direction and a second direction which are parallel to a top surface of the substrate layer to cross each other, and the dummy line extends in a diagonal direction relative to the first direction or the second direction.

(4) The touch sensor according to the above (3), wherein the sensing electrode has a diamond shape, and the dummy line has a straight line shape.

(5) The touch sensor according to the above (3), wherein the sensing electrodes include first sensing electrodes arranged along the first direction, and second sensing electrodes arranged along the second direction, wherein the first sensing electrodes have an island pattern shape and the second sensing electrodes are connected to each other by connecting portions extending in the second direction.

(6) The touch sensor according to the above (5), further comprising bridge electrodes electrically connecting the first sensing electrodes neighboring each other.

(7) The touch sensor according to the above (6), wherein the dummy line extends in the diagonal direction to cross the connecting portion or the bridge electrode.

(8) The touch sensor according to the above (1), wherein dummy regions are defined between the boundaries of the sensing electrodes neighboring each other, and the dummy line is disposed in each of the dummy regions.

(9) The touch sensor according to the above (8), wherein the dummy line is divided into at least two lines in the dummy region.

(10) The touch sensor according to the above (1), wherein the sensing electrode includes electrode lines therein, and the dummy line extends in a diagonal direction relative to the electrode lines.

(11) The touch sensor according to the above (10), wherein the electrode lines extend in a linear shape, a wavy shape or a saw-tooth shape.

(12) The touch sensor according to the above (10), wherein the sensing electrodes further include connecting patterns therein which connect the electrode lines neighboring each other.

(13) The touch sensor according to the above (12), wherein the sensing electrodes include slits therein which are confined by the electrode lines and the connecting patterns neighboring each other.

(14) An image display device including the touch sensor according to any one of the above (1) to (13).

In the touch sensor according to exemplary embodiments as described above, a dummy line may be formed in a dummy region defined between neighboring sensing electrodes. The dummy line may have a shape substantially the same as that of a boundary of the sensing electrode. Thus, a regional pattern deviation may be reduced by the dummy line so that an electrode visibility may be also reduced.

A linearity and continuity of a mutual capacitance between a first sensing electrode and a second sensing electrode may be maintained by the dummy line so that a sensitivity of the touch sensor may be further enhanced.

In exemplary embodiments, the dummy line may be divided into a plurality of lines in the dummy region to have a width in which the dummy line may not be viewed by the user, and the sensitivity and signal speed may be increased.

In some embodiments, the sensing electrode may include a plurality of slits therein. A light scattering or a light diffraction may be induced by the slits so that a visibility of the sensing electrode may be reduced. Further, an aperture ratio of the touch sensor may be improved by the slits to achieve a high transmittance structure.

The touch sensor may be effectively applied to an image display device with high resolution to improve electrical, electrical and mechanical properties thereof.

