The above and other features of the present invention will be described in reference to certain exemplary embodiments thereof with reference to the attached drawings in which:
Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.
As shown in
The first substrate 111 is made of a flexible material with an elasticity such as that of plastic.
The common electrode 142 is made of a transparent conductive material and formed on the first substrate 111. The common electrode 142 forms an electric field with the pixel electrode 122 to drive pigments 162 with a positive polarity and pigments 164 with a negative polarity.
Each of a plurality of micro capsules 160 contains an electronic ink with a black pigment 162 with a positive polarity and a white pigment 164 with a negative polarity. The pigments 162 with a positive polarity and the pigments 164 with a negative polarity respectively move to the pixel electrode 122 and the common electrode 142 which have an opposite polarity thereto when an electric potential difference occurs between the pixel electrode 122 and the common electrode 142. For example, if a pixel voltage with a positive polarity is applied to the pixel electrode 122 and a common voltage with a negative polarity is applied to the common electrode 142, the pigments 162 with a positive polarity move to the common electrode 142, and the pigments 164 with a negative polarity move to the pixel electrode 122, whereby the pigments 162 with a positive polarity and the pigments 164 with a negative polarity are separated from each other. Accordingly, images of black and white are realized through the electrophoretic display panel 190.
The adhesive layer 144 serves to adhere the first array substrate 140 to the second array substrate 150.
The second array substrate 150 comprises gate lines 102 arranged in a transverse direction, data lines 104 arranged in a perpendicular direction to the gate lines 102, thin film transistors (TFTs) 130 connected to the gate lines 102 and the data lines 104, a pixel electrode 122 electrically connected to the TFT 130, first and second touch conductive lines 182 and 184 which detect the coordinate of a location selected by a user, a first conductive touch spacer 170 formed on the first touch conductive line 182, and a second conductive touch spacer 180 formed on the second touch conductive line 184.
The TFT 130 selectively supplies a pixel voltage to the pixel electrode 122 from the data line 104 in response to a gate signal transmitted from the gate line 102. To this end, the TFT 130 comprises a gate electrode 106 connected to the gate line 102, a source electrode 108 connected to the data line 104, a drain electrode 110 connected to the pixel electrode 122, an active layer 114 for forming a channel between the source electrode 108 and the drain electrode 110 while overlapping the gate electrode 106 with a gate insulating layer 112 disposed therebetween, and an ohmic contact layer 116 for an ohmic contact between the active layer 114 and the source and drain electrodes 108 and 110.
The pixel electrode 122 is formed on a passivation layer 118 and electrically connected to the drain electrode 110 exposed via a contact hole 120. The pixel electrode 122 uses the pixel voltage supplied through the TFT 130 to generate an electric potential difference with the common voltage supplied to the common electrode 142.
The first and second touch conductive lines 182 and 184 may be formed over the gate line 102 in the same direction as the gate line 102 or may be formed over the data line 104 in the same direction as the data line 104. Alternatively, as shown in
At this time, the first and second touch conductive lines 182 and 184 are insulated from each other.
In case where the first and second touch conductive lines 182 and 184 are formed over the gate line 102 in the same direction as the gate line 102, the first and second touch conductive lines 182 and 184 may be formed on the gate insulating layer 112 using the same material as the data line 104 as shown in
In case where the first and second touch conductive lines 182 and 184 are formed over the data line 104 in the same direction as the data line 104, the first and second touch conductive lines 182 and 184 may be formed on the second substrate 101 using the same material as the gate line 102 as shown in
The first conductive touch spacer 170 is formed on the first touch conductive line 182, and the second conductive touch spacer 180 is formed on the second touch conductive line 184. Thus, the first and second conductive touch spacers 170 and 180 are separated from each other, facing each other in a transverse direction. The first and second conductive touch spacers 170 and 180 are apart from each other by a relatively short distance “d”, e.g., 10 μm to 20 μm so that the first and second conductive touch spacers 170 and 180 can contact each other by pressure generated by a pen or a finger. The first and second conductive touch spacers 170 and 180 have the elasticity that they are easily bent by the pressure generated by a pen or a finger and are easily recovered to the original state.
To this end, the first and second conductive touch spacers 170 and 180 may be shaped such that their widths become narrower as they extend toward the first substrate 111 from the first and second touch conductive lines 182 and 184 while maintaining the separation distance “d”, as shown in
In more detail, referring to
Alternatively, as shown in
The upper portions of the first and second conductive touch spacers 170 and 180 have relatively narrow widths and accordingly have a high elasticity. The upper portions of the first and second conductive touch spacers 170 and 180 with the narrow width are easily bent by the pressure of the pen or the finger and easily are recovered to the original state. The lower portions of the first and second conductive touch spacers 170 and 180 have relatively wide widths and so stably support and fix the first and second conductive touch spacers 170 and 180.
The first and second touch conductive spacers 170 and 180 are formed using an etching technique, preferably a dry etching technique. Preferably, the first and second conductive touch spacers 170 and 180 are made of metal suitable for a dry-etching such as molybdenum (Mo), aluminum (Al), tungsten (W), and silver (Ag).
As described above, the first and second conductive touch spacers 170 and 180 contact each other, as shown in
At this time, a resistance value of a location where the first and second conductive touch spacers 170 and 180 contact varies differently from other positions. The electric current or voltage varies depending on the varied resistance value, and the electrophoretic display panel 190 outputs the varied electric current or voltage as a coordinate signal through the first and second touch conductive lines 182 and 184.
A touch controller 198 shown in
The electrophoretic display panel described above detects the coordinate of the touch position by using the resistive method, but the present invention is not limited to the resistive/conductive method and may use different methods such as the capacitive or electromagnetic inductive method to detect the coordinate of the touch position.
For example, in case of the capacitive method, the touch spacers may not make contact, but may change in separation distance when a finger of a user or a pen touches the first substrate. The capacitance value at the touch position then varies differently from other positions. The electrophoretic display panel outputs the varied voltage depending on the varied capacitance value as a coordinate signal through the first and second touch conductive lines 182 and 184.
In case of the electromagnetic inductive method, an alternating current (AC) signal is applied to the first and second touch conductive lines 182 and 184 used as a coil, and then an electronic pen having a resonance circuit comprised of a coil and a capacitor touches the first substrate 111 of the electrophoretic display panel 190 as shown in
As described above, the electrophoretic display device of the present invention includes the first and second conductive touch spacers which face each other in a transverse direction and are arranged in the electrophoretic display panel. The electrophoretic display device of the present invention can detect the touch position of the user through the first and second touch conductive lines connected to the first and second touch spacers.
Although the present invention has been described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that a variety of modifications and variations may be made to the present invention without departing from the spirit or scope of the present invention defined in the appended claims, and their equivalents.
Number | Date | Country | Kind |
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10-2006-0072543 | Aug 2006 | KR | national |