Display substrate, method of manufacturing the same, display device having the display substrate and method of driving the display device
View Patent ↗A display substrate includes a plurality of pixel parts, each including a first and second gate lines, a source line, first, second, and third transistors, and a pumping capacitor. A display device includes a display panel, a gate driving part, a source driving part, and an output selecting part. Each pixel part of a display panel includes a transmissive part, a reflective part, and an adjusting part. The adjusting part adjusts the transmission voltage charged in the reflective part to a reflection voltage based on a control voltage. Thus, transmission voltage applied to the transmissive part is adjusted to reflection voltage to be applied to the reflective part. Therefore, optical reflectivity and optical transmissivity versus voltage are matched with each other, while embodying a single cell-gap and applying a single voltage.
1. A display device comprising:
a display panel including a plurality of pixel parts, each pixel part comprising:
a transmissive part in which a transmission voltage transmitted through a source line according to activation of a first gate line is charged;
a reflective part in which the transmission voltage is charged; and
an adjusting part that adjusts the transmission voltage charged in the reflective part to a reflection voltage based on a control voltage transmitted through the source line according to activation of a second gate line;
a gate driving part outputting first and second gate signals to the first and second gate lines respectively, the first and second gate signals activating both the first and second gate lines in a first period, and activating only the second gate line in a second period;
a source driving part outputting the transmission voltage in the first period; and
an output selecting part outputting the transmission voltage to the source line in the first period, and selectively outputting the control voltage to the source line in the second period.
2. The display device of claim 1 , wherein the first period is an earlier period of a horizontal period (“ 1 H”), and the second period is a latter period of the 1 H.
3. The display device of claim 1 , wherein the transmissive part comprises:
a first transistor including a first gate electrode connected with the first gate line;
a first liquid crystal capacitor connected with a first drain electrode of the first transistor; and
a first storage capacitor connected with the first drain electrode.
4. The display device of claim 3 , wherein the reflective part comprises:
a second transistor including a second gate electrode connected with the first gate line, and a second source electrode connected with the first drain electrode;
a second liquid crystal capacitor connected with a second drain electrode of the second transistor; and
a second storage capacitor connected with the second drain electrode.
5. The display device of claim 4 , wherein the adjusting part comprises:
a third transistor including a third gate electrode connected with the second gate line, and a third source electrode connected with the source line; and
a pumping capacitor including a first terminal connected with a third drain electrode of the third transistor, and a second terminal connected with the second drain electrode.
6. The display device of claim 4 , wherein the adjusting part comprises:
a third transistor including a third gate electrode connected with the second gate line, a third source electrode connected with the source line, and a third drain electrode connected with a first source electrode of the first transistor; and
a pumping capacitor including a first terminal connected with a third drain electrode of the third transistor, and a second terminal connected with the second drain electrode.
7. The display device of claim 6 , wherein a voltage difference (ΔV 1 ) between the transmission voltage and the reflection voltage is defined as a following equation:
Δ
V
1
=
Δ
V
2
×
C
P
C
LC
+
C
P
+
C
ST
,
wherein ΔV 2 is a voltage difference between the transmission voltage and the control voltage, C LC is capacitance of the second liquid crystal capacitor, C ST is capacitance of the second storage capacitor, and C P is capacitance of the pumping capacitor.
8. The display device of claim 6 , wherein the first liquid crystal capacitor includes a transparent electrode connected with the first drain electrode, and the second liquid crystal capacitor includes a reflective electrode connected with the second drain electrode.
9. The display device of claim 6 , further comprising a voltage generating part outputting the control signal, the voltage generating part further outputting a common voltage to common electrodes of the first and second liquid crystal capacitors and to common electrodes of the first and second storage capacitors, respectively.
10. The display device of claim 9 , wherein the control voltage has substantially a same electric potential level as the common voltage.