Liquid crystal display
View Patent ↗A liquid crystal display (LCD) device is provided. The LCD device includes a LCD panel, which further includes a plurality of scan lines, a gate driving circuit, a clock circuit. The clock circuit includes a clock generator and an adjusting circuit. The clock generator generates a clock signal having a first high voltage level and a first low voltage level. The adjusting circuit, coupled to the clock generator, receives the clock signal and generates an adjusted clock signal having the same period as the clock signal. The adjusted clock signal has a second high voltage level and a second low voltage level. The gate driving circuit, coupled to the clock circuit, receives the adjusted clock signal as a gate driving signal in order to drive the scan lines.
1. A liquid crystal display (LCD) device, comprising a LCD panel, said LCD panel comprising:
a plurality of scan lines;
a gate driving circuit; and
a clock circuit, said clock circuit comprising:
a clock generator for generating a clock signal having a first high voltage level and a first low voltage level; and
an adjusting circuit, coupled to said clock generator, for receiving said clock signal and generating an adjusted clock signal, said adjusted clock signal having the same period as said clock signal and having a second high voltage level and a second low voltage level;
wherein said clock signal has a first transition period from said first low voltage level to said first high voltage level, said adjusted clock signal has a second transition period from said second low voltage level to said second high voltage level, and said first transition period is shorter than said second transition period;
wherein said gate driving circuit, coupled to said clock circuit, receives said adjusted clock signal as a gate driving signal in order to drive said scan lines;
wherein said adjusting circuit comprises:
a divider; and
a CMOS inverter, said CMOS inverter comprising:
a PMOS, a source of said PMOS receiving a high level signal carrying said second high voltage level; and
a NMOS, a source of said NMOS receiving a low level signal carrying said second low voltage level;
wherein said divider is connected to the gate of said PMOS, said clock signal is divided by said divider and is received by said divider and said gate of said NMOS to form gate-source voltages (Vgs) on said NMOS and said PMOS, and said adjusted clock signal is outputted from drains of said NMOS and said PMOS.
2. A LCD device according to claim 1 , wherein said clock signal is a square-wave signal.
3. A LCD device according to claim 1 , wherein said adjusting circuit comprising a level shifter.
4. A LCD device according to claim 1 , wherein said second high voltage level and said second low voltage level are respectively the highest voltage level and the lowest voltage level of said gate driving signal.
5. A LCD device according to claim 1 , wherein said divider is a variable divider, said divider divides said clock signal in response to a control signal to adjust said gate-source voltage.
6. A LCD device according to claim 1 , wherein said divider comprises a variable resistor.
7. A LCD device according to claim 1 , where each of said scan lines comprises a plurality of LTPS TFTs.
8. A LCD device according to claim 7 , wherein said plurality of LTPS TFTs and said gate driving circuit are formed on a same glass substrate.
9. A LCD device according to claim 1 , further comprising a power supply connected to said LCD panel for supplying power to said LCD panel.
10. A LCD device according to claim 1 , wherein said LCD device is embedded in a mobile phone, a digital still-picture camera, a car navigation system, a mobile DVD-player, a gaming device, or a hand-held consumer appliance, a television, a computer monitor, a large-screen consumer electronics device, or a professional appliance.
11. An apparatus comprising a liquid crystal display (LCD) panel, said apparatus comprising a mobile phone, a digital still-picture camera, a car navigation system, a mobile DVD-player, a gaming device, or a hand-held consumer appliance, a television, a computer monitor, a large-screen consumer electronics device, or a professional appliance, and said LCD panel comprising:
a plurality of scan lines;
a gate driving circuit; and
a clock circuit, said clock circuit comprising:
a clock generator for generating a clock signal having a first high voltage level and a first low voltage level; and
an adjusting circuit, coupled to said clock generator, for receiving said clock signal and generating an adjusted clock signal, said adjusted clock signal having the same period as said clock signal and having a second high voltage level and a second low voltage level,
wherein said clock signal has a first transition period from said first low voltage level to said first high voltage level, said adjusted clock signal has a second transition period from said second low voltage level to said second high voltage level, and said first transition period is shorter than said second transition period,
wherein said gate driving circuit, coupled to said clock circuit, receives said adjusted clock signal as a gate driving signal in order to drive said scan lines,
wherein said adjusting circuit comprises:
a divider; and
a CMOS inverter, said CMOS inverter comprising:
a PMOS, a source of said PMOS receiving a high level signal carrying said second high voltage level; and
a NMOS, a source of said NMOS receiving a low level signal carrying said second low voltage level, and
wherein said divider is connected to the gate of said PMOS, said clock signal is divided by said divider and is received by said divider and said gate of said NMOS to form gate-source voltages (Vgs) on said NMOS and said PMOS, and said adjusted clock signal is outputted from drains of said NMOS and said PMOS.