Shift register and touch display apparatus thereof

• US 10,642,395 B2
• Filed: 09/06/2018
• Issued: 05/05/2020
• Est. Priority Date: 07/04/2018
• Status: Active Grant

• Current Assignee: Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: Weng, Yu-Fu, Lin, Chien-Wen, Cheng, Tzu-Yu
• Primary Examiner(s): Jansen, II, Michael J
• Application Number:
  US16/123,055
• Publication Number:
  US 20200012368A1
• Time in Patent Office: 607 Days
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G09G 2310/0267 Details of drivers for scan electrodes, other than drivers for liquid crystal, plasma or OLED displays
• CPC Class Codes: G09G 2310/0286 Details of a shift registers arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/063 Waveforms for resetting the whole screen at once
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/3266 Details of drivers for scan electrodes
• CPC Class Codes: G09G 3/3674 Details of drivers for scan electrodes
• CPC Class Codes: G11C 19/28 using semiconductor elements G11C19/14, G11C19/36 take precedence

Abstract

A shift register driving a touch display device generates shifted pulse signals shifted by a specified phase. The shift register includes unit circuits connected in multiple stages. Each unit circuit includes an output terminal, an input transistor, an output transistor, and a pull-up transistor. The input transistor is controlled by a first control signal and outputs a high-level voltage to a first node based on the value of a trigger signal. The output transistor outputs the shifted pulse signal, which is synchronous with a clock control signal, based on the value of the high-level voltage of the first node. A blank period is inserted between the Nth unit circuit and the (N+1)th unit circuit. After the blank period, the pull-up transistor clamps the voltage of the output terminal of the (N+1)th unit circuit at a high-level voltage.

Claims

1. A shift register for generating a plurality of shifted pulse signals shifted by a specified phase, the shift register comprising:

a plurality of cascade-connected unit circuits, each unit circuit configured to receive a clock control signal, and each unit circuit comprising;

an output terminal, electrically coupled to at least one external signal line, and configured to provide a shifted pulse signal to the connected at least one external signal line;

an input transistor, controlled by a first control signal, and configured to output a high-level voltage to a first node based on a trigger signal for activating the unit circuit;

an output transistor, including a first control terminal connected to the first node, a first connection terminal receiving the clock control signal, and a second connection terminal connected to the output terminal, the output transistor outputting the shifted pulse signal to the output terminal in response to the high-level voltage of the first node, the shifted pulse signal being synchronous with the clock control signal;

a storage capacitor, the two opposite terminals of which are connected with the first node and the output terminal; and

a pull-up transistor, including a second control terminal connected to the output terminal, a third connection terminal connected to the second control terminal, and a fourth connection terminal connected to a high voltage power source;

wherein the shifted pulse signal of the (N+1)th unit circuit outputted to the (N+1)th signal line is shifted by a specified phase by compared to the shifted pulse signal of the Nth unit circuit outputted to the Nth signal line;

a blank period is inserted between two adjacent shifted pulse signals of two adjacent unit circuits;

during the (N+1)th unit circuit outputting the shifted pulse signal after the blank period is inserted between the Nth unit circuit and the (N+1)th unit circuit, the pull-up transistor clamps the voltage of the output terminal of the (N+1)th unit circuit at a high-level voltage;

wherein the unit circuit further comprises a reset module to receive a reset signal;

the reset module comprises a pull-down transistor;

the pull-down transistor comprises a third control terminal for receiving the reset signal, a fifth connection terminal connected with the output terminal, and a sixth connection terminal connected to a low voltage power source;

the pull-down transistor outputs a low-level voltage to the output terminal based on the reset signal, which causes the current unit circuit to reset;

wherein the reset module further receives a second control signal;

the reset module further comprises a first transistor;

the first transistor comprises a fourth control terminal for receiving the second control signal, a seventh connection terminal connected with the first node, and an eighth connection terminal connected to the low voltage power source;

the first transistor outputs the low-level voltage to the first node based on the second control signal.

2. The shift register of claim 1, wherein during the blank period, each unit circuit stops outputting the shifted pulse signal.

3. The shift register of claim 1, wherein each of the clock control signal, the first control signal, and the second control signal originate from three adjacent clock lines respectively, and the signals of the first control signal, the clock control signal, and the second control signal are sequentially shifted by the specified phase shift.

4. The shift register of claim 1, wherein the reset module further comprises a second transistor;

the second transistor comprises a fifth control terminal for receiving the reset signal, a ninth terminal connected with the first node, and a tenth connection terminal connected to the low voltage power source;

the second transistor output the low-level voltage to the first node based on the reset signal.

5. A touch display apparatus comprising:

a display region; and

a non-display region surrounding the display region, and the non-display region comprising;

at least one gate driver with at least one shift register disposed in the non-display region;

the shift register comprising a plurality of cascade-connected unit circuits, and configured to generate a plurality of shifted pulse signals shifted by a specified phase shift;

each unit circuit configured to receive an clock control signal, each of the unit circuit comprising;

an output terminal, electrically coupled to at least one external signal line, and configured to provide a shifted pulse signal to the connected at least one external signal line;

an input transistor, controlled by a first control signal, and configured to output a high-level voltage to a first node based on a trigger signal activating the unit circuit;

an output transistor, including a first control terminal connected to the first node, a first connection terminal receiving the clock control signal, and a second connection terminal connected to the output terminal, the output transistor outputting the shifted pulse signal to the output terminal in response to the high-level voltage of the first node, the shifted pulse signal being synchronous with the clock control signal;

a storage capacitor, the two opposite terminals of which are connected with the first node and the output terminal; and

a pull-up transistor, including a second control terminal connected to the output terminal, a third connection terminal connected to the second control terminal, and a fourth connection terminal connected to a high voltage power source;

wherein the shifted pulse signal of the (N+1)th unit circuit outputted to the (N+1)th signal line is shifted a specified phase by compared to the shifted pulse signal of the Nth unit circuit outputted to the Nth signal line;

a blank period is inserted between two adjacent shifted pulse signals of two adjacent unit circuits;

during the (N+1)th unit circuit outputting the shifted pulse signal after the blank period is inserted between the Nth unit circuit and the (N+1)th unit circuit, the pull-up transistor clamps the voltage of the output terminal of the (N+1)th unit circuit at a high-level voltage;

wherein the unit circuit further comprises a reset module to receive a reset signal;

the reset module comprises a pull-down transistor;

the pull-down transistor comprises a third control terminal for receiving the reset signal, a fifth connection terminal connected with the output terminal, and a sixth connection terminal connected to a low voltage power source;

the pull-down transistor outputs a low-level voltage to the output terminal based on the reset signal, which causes the current unit circuit to reset;

wherein the reset module further receives a second control signal;

the reset module further comprises a first transistor;

the first transistor comprises a fourth control terminal for receiving the second control signal, a seventh connection terminal connected with the first node, and an eighth connection terminal connected to the low voltage power source;

the first transistor outputs the low-level voltage to the first node based on the second control signal.

6. The touch display apparatus of claim 5, wherein during the blank period, the entire unit circuits stops outputting the shifted pulse signal.

7. The touch display apparatus of claim 5, wherein the clock control signal, the first control signal, and the second control signal originate from three adjacent clock lines respectively, and the signal of the first control signal, the clock control signal, and the second control signal are sequentially shifted by the specified phase shift.

8. The touch display apparatus of claim 5, wherein the reset module further comprises a second transistor;

the second transistor comprises a fifth control terminal received the reset signal, a ninth connection terminal connected with the first node, and a tenth connection terminal connected to the low voltage power source;

the second transistor outputs the low-level voltage to the first node based on the value of the reset signal.

9. The touch display apparatus of claim 5, wherein the touch display apparatus selectively operated under a touch period and a display period, the display period comprises a plurality of sub-display period;

the touch period comprises a plurality of sub-touch periods, each sub-touch period is inserted between two adjacent sub-display periods;

the blank period is the sub-touch period.