Himax Technologies, Inc.

Raydium Semiconductor Corporation

Kai-Lan Chuang

Chien-Ru Chen

Guo-Ming Lee

Ying-Lieh Chen

Chuan-Che Lee

Wen-Teng Fan

Ching-Chung Lee

Chen-Yu Wang

Zen-Wen Cheng

A gate driver includes a gate driving main circuit and a power sequence control circuit. The gate driving main circuit disposed between an operating voltage and ground is coupled to a first gate voltage and a second gate voltage. The operating voltage is higher than ground and first gate voltage is higher than second gate voltage. The power sequence control circuit includes first-type transistors, a second-type transistor, a transistor and a judging circuit. The first-type transistors are coupled in series between first gate voltage and a first node and their gates are coupled to a second node. The second-type transistor is coupled between first node and second gate voltage and its gate is coupled to second node. The transistor is coupled between first gate voltage and gate driving main circuit and its gate is coupled to first node. The judging circuit generates an output signal to second node.

Gate driver

A power on reset circuit applied to a gate driver of a display apparatus is disclosed. The power on reset circuit is coupled between an operating voltage and a ground terminal. The power on reset circuit includes an output terminal, a first transistor, a second transistor, a resistor, and a buffer circuit. The first transistor is coupled between the operating voltage and a first node. A gate of first transistor is coupled to the first node. The second transistor is coupled between the operating voltage and the first node. A gate of second transistor is coupled to the ground terminal. The resistor is coupled between the first node and ground terminal. The buffer circuit is coupled between the first node and output terminal and outputs a reset signal through the output terminal. A second threshold voltage of second transistor is larger than a first threshold voltage of first transistor.

Power on reset circuit applied to gate driver of display apparatus

A level shifter applied in a driving circuit of a display is disclosed. The level shifter includes a first stage of level shifting unit and a second stage of level shifting unit and used to convert an input voltage signal with low voltage level into an output voltage signal with high voltage level. In one example, the total number of the transistors needed by the level shifter is much fewer than that of the prior art, and additional voltage sources are not needed to provide middle voltages. The manufacturing cost of the exemplary level shifter can be reduced and the signal level shifting efficiency of multi-power domain can be enhanced.

Level shifter of driving circuit and operating method thereof

A source driver pre-charging apparatus including a data detection module, a determining module, and a pre-charging module is disclosed. The data detection module captures a first most significant bit having N bits in a current data and a second most significant bit having N bits in a former data and compares them to generate a compared result. N is a positive integer larger than or equal to 2. The determining module judges whether any data is transited from a first grey-level region to a second grey-level region between the former data and the current data and at least one other grey-level region is existed between the first grey-level region and the second grey-level region. If the judgment result of the determining module is yes, the pre-charging module performs a pre-charging action on an output voltage of a source driver.

Pre-charging apparatus of source driving circuit and operating method thereof

A driving apparatus applied in a liquid crystal display are disclosed. Its first channel includes a first latching module, a first level-shifting module, a P-type digital/analog converting module, and a first RR module, the second channel includes a second latching module, a second level-shifting module, a N-type digital/analog converting module, and a second RR module. The P-type digital/analog converting module and N-type digital/analog converting module are selectively coupled to the first RR module or the second RR module. The first latching module receives a first digital signal and the first latching module outputs a first analog signal corresponding to the first digital signal. The second latching module receives a second digital signal and the second latching module outputs a second analog signal corresponding to the second digital signal.

Driving apparatus

A driving apparatus applied in a liquid crystal display are disclosed. Its first channel includes a first latching module, a first level-shifting module, a P-type digital/analog converting module, a first RR module, and a P-type amplifying module, the second channel includes a second latching module, a second level-shifting module, a N-type digital/analog converting module, a second RR module, and a N-type amplifying module. The P-type digital/analog converting module and N-type digital/analog converting module are selectively coupled to the first RR module or the second RR module. The first latching module receives a first digital signal and the first latching module outputs a first analog signal corresponding to the first digital signal. The second latching module receives a second digital signal and the second latching module outputs a second analog signal corresponding to the second digital signal.

A sensor pixel and a touch panel using the same are provided herein, wherein the touch panel has m scan lines and n readout lines. The sensor pixel includes a sensing capacitor, a readout transistor, a reset transistor, a base transistor, and a photo transistor. The photo transistor included in the sensor pixel produces a photo leakage current when it is exposed to a light. The light obstruction characteristic of the photo transistor is utilized to detect the locations of the touched sensor pixels. By proper timing control, the present invention not only can be applied to the multi-finger detection, but also is easy to be implemented.

Sensor pixel and touch panel thereof

A reset circuit and a delay circuit are provided. The delay circuit includes a first resistor module, a second resistor module, a switch module and a capacitor module. First terminals of the first and the second resistor modules are coupled respectively to a first voltage and a second voltage. The switch module have a control terminal served as a input terminal of the delay circuit, a first terminal served as a output terminal of the delay circuit, a second terminal coupled to a second terminal of the first resistor module, and a third terminal coupled to a second terminal of the second resistor module. In the delay circuit, the first terminal selectively connected to the second terminal or the third terminal in accordance with the control terminal. The capacitor module couples between the first terminal of the switch module and the second voltage.

Circuit for resetting system and delay circuit

A readout apparatus and a multi-channel readout apparatus for a touch panel are provided to integrate different types of readout circuit. The readout apparatus set to a first mode reads the touch panel with a small amount of charges through an integrator. The readout apparatus set to a second mode reads a sensing current of a current type touch panel through a current to voltage converting unit and an inverting amplifier, so as to save a chip area. The multi-channel readout apparatus set to a third mode applies multiple channels to alternatively share an integrator to read the touch panel with a large amount of charges, so that an amount of feedback capacitors (integral capacitors) having a great area can be greatly reduced. Therefore, readout apparatus of the present invention can not only reduce a chip area, but can also be applied to various types of the touch panel.

Readout apparatus and multi-channel readout apparatus for touch panel

A control circuit for a start-up circuit that induces current flow in a bandgap circuit during a start-up phase is disclosed. A comparator passes a power supply to the start-up circuit according to an internal node of the bandgap circuit after the start-up phase. An activating circuit is used to activate the comparator to obtain the power supply at an output earlier than another output node of the comparator.

Control circuit having a comparator for a bandgap circuit

A multi-channel integrator is provided. The multi-channel integrator includes an integrator and a plurality of channels. Each of the channels includes an input selector and a unit-gain amplifier. The input selector has a common terminal, a first selecting terminal and a second selecting terminal. The input selector selectively electrically connects the common terminal to the first selecting terminal or to the second selecting terminal. The first selecting terminal of the input selector is coupled to an input terminal of the integrator. An input terminal of the unit-gain amplifier is coupled to the second selecting terminal of the input selector.

Multi-channel integrator

An optical sensor is disclosed. Each sensor pixel circuit of the optical sensor includes a first readout TFT for reading out voltage of a charge node, a second readout TFT for controllably resetting the charge node to a first reset voltage, and a photo TFT for discharging the voltage at the charge node to a second reset voltage in absence of an object(s).

Optical sensor with photo TFT

A multi-channel integrator includes a first switch, a second switch, and a plurality of integration units. First terminals of the first and second switches receive a first reference voltage. Each of the integration units includes an operational amplifier (OP-AMP), a feedback switch, a third switch, a fourth switch, and a feedback capacitor. A second input terminal of the OP-AMP receives a second reference voltage. Two terminals of the feedback switch are respectively coupled to a first input terminal and an output terminal of the OP-AMP. First terminals of the third switch and the fourth switch are respectively coupled to the first input terminal and the output terminal of the OP-AMP. A first terminal of the feedback capacitor is coupled to the second terminals of the first and the third switches. A second terminal of the feedback capacitor is coupled to the second terminals of the second and the fourth switches.

A readout circuit for touch panel includes first and second switches, an operational amplifier (OP-AMP), a feedback capacitor, a comparison unit, and a counter. A first input terminal and an output terminal of the OP-AMP are respectively coupled to a second terminal of the first switch and an input terminal of the comparison unit. A second input terminal of the OP-AMP receives a reference voltage. Two terminals of the feedback capacitor and the second switch are respectively coupled to the first input terminal and the output terminal of the OP-AMP. The comparison unit selects first or second threshold voltages to compare with an output of the OP-AMP according to a output of the comparison unit. An input terminal of the counter receives the output of the comparison unit.

Readout circuit for touch panel

A source driver of an LCD includes a first and second power sources, a first and second inversion units, a first and second charging switches, and a first and second discharging switches. The first charging switch is coupled to the first power source, a first end of the first inversion unit, and a second end of the second inversion unit. The second charging switch is coupled to the first power source, a first end of the second inversion unit, and a second end of the first inversion unit. The first discharging switch is coupled to the second power source, the second end of the first inversion unit, and the first end of the second inversion unit. The second discharging switch is coupled to the second power source, the second end of the second inversion unit, and the first end of the first inversion unit.

Growing community of inventors

Tainan, Taiwan

Kai-Lan Chuang