CN100411005C - control circuit with electrostatic protection and liquid crystal display - Google Patents

Abstract

The control circuit has the function of electrostatic protection and comprises a plurality of shift registers; a plurality of buses coupled to the plurality of shift registers; a common terminal; a set of electrostatic protection elements coupled to a set of buses of the plurality of buses for protecting the plurality of buses from being damaged by electrostatic current; and a set of discharge paths coupled to the set of ESD protection devices and the common terminal for providing the discharge paths to the ESD current, wherein the set of ESD protection devices comprises: a first ESD protection device coupled to a first bus of the plurality of buses, the set of discharge paths including a first discharge path coupled to the first ESD protection device and the common node; and a second ESD protection device coupled to the first bus, the set of discharge paths further including a second discharge path coupled to the second ESD protection device and the common terminal.

Description

Control circuit and liquid crystal display with electrostatic protection

technical field

The invention relates to a control circuit with static electricity protection, in particular to a control circuit with static electricity protection on a liquid crystal display.

Background technique

Please refer to Figure 1. FIG. 1 is a schematic diagram of a liquid crystal display 100 . The liquid crystal display 100 includes a glass substrate 110 , a liquid crystal layer 120 and a glass substrate 130 . The glass substrate 110 includes a color filter. The glass substrate 130 includes thin film transistors (thin film transistor, TFT).

Please refer to Figure 2. FIG. 2 is a schematic diagram of the glass substrate 130 . As shown in the figure, the glass substrate 130 includes a plurality of horizontal gate lines intersecting with a plurality of vertical source lines to form a plurality of pixel regions, such as the pixel region 210 . For example, the pixel region 210 includes a thin film transistor Q1 and a storage capacitor C1. The gate of the thin film transistor Q1 is coupled to an adjacent gate line, its source is coupled to an adjacent source line, and its drain Coupled to storage capacitor C1. One end of the storage capacitor C1 is coupled to the drain of the thin film transistor Q1, and the other end is coupled to a common end VCOM. The other ends of the storage capacitors in all the pixel areas are coupled to the common terminal VCOM, so that all the storage capacitors have a common voltage level.

Please refer to Figure 3. FIG. 3 is a schematic diagram of a glass substrate 330 with electrostatic protection. Since the gate lines and source lines of the glass substrate 330 are coupled to the edge of the glass substrate 330 for receiving external gate signals and source signals, electrostatic discharge (ESD) events are easily generated at the edge of the panel. ), and break the thin film transistor. Therefore, an electrostatic protection component is placed near the edge of the glass substrate 330 between the gate line and the source line. As shown in the figure, the ESD protection element E1 is coupled to the first gate line, the ESD protection element E2 is coupled to the second gate line, and so on. The other ends of all the ESD protection components are coupled to a common end VA, which is a short ring. In this way, the ability of electrostatic protection is enhanced to dissipate electrostatic discharge current faster.

However, another glass substrate cannot completely prevent the damage caused by the electrostatic discharge current in the above-mentioned manner. Please refer to Figure 4. FIG. 4 is a schematic diagram of a glass substrate 400 . The glass substrate 400 includes a pixel module 410 , a shift register module 420 , and a bus module 430 . The pixel module 410 includes a plurality of pixel regions and an electrostatic protection module 412 . The pixel module 410 can imitate the designs shown in FIG. 2 and FIG. 3 , and multiple horizontal gate lines and multiple vertical source lines intersect to form multiple pixel regions, as shown in the pixel region 411 . The ESD protection module 412 includes a plurality of ESD protection elements E5˜En and a common terminal VA. The shift register module 420 includes a plurality of shift registers S1˜Sn, and each shift register has a corresponding gate line. The first shift register S1 is used to receive the start signal ST, and then send the gate signal to the first gate line, and the subsequent shift register S2 sends the gate signal to the corresponding gate line in sequence according to the first gate signal The gate lines are deduced by analogy until the Sn outputs the nth gate signal to complete the scanning of a page. The bus module 430 includes buses B1 , B2 , and B3 for providing bias voltage VSS, clock signals XCK and CK to the shift register module 420 . It can be seen from the figure that the difference between the glass substrate 400 and the glass substrate 130 is that the glass substrate 400 has more shift register modules 420 and bus modules 430 . But for the shift register module 420 and the bus module 430, there is no ESD protection design. Although the shift register module 420 itself has the ability of electrostatic protection, the bus module 430 does not. Moreover, the bias voltage VSS received by the bus module 430, the clock signals XCK and CK are all transmitted from the outside of the glass substrate 400, so the bus module 430 needs to be coupled to the edge of the glass substrate 400, and it is more likely to be affected by electrostatic discharge events and cause a short circuit. Or the situation of disconnection makes it easy to fail when manufacturing the glass substrate 400 .

Contents of the invention

Therefore, the main purpose of the present invention is to provide a control circuit with electrostatic protection function to solve the above problems.

The present invention provides a control circuit with electrostatic protection, comprising a plurality of shift registers; a plurality of buses coupled to the plurality of shift registers; a common terminal; a group of electrostatic protection components coupled to the plurality of buses A group of buses, used to protect the plurality of buses from being damaged by electrostatic current; and a group of discharge paths, coupled between the group of electrostatic protection components and the common end, to provide a discharge path for electrostatic current; wherein the common end Used to discharge the electrostatic current transmitted through the group of discharge paths, wherein the group of electrostatic protection components includes: a first electrostatic protection component coupled to a first bus of the plurality of buses, and the group of discharge paths includes a first A discharge path, coupled to the first ESD protection component and the common end; and a second ESD protection component, coupled to the first bus, the group of discharge paths also includes a second discharge path, coupled to the The second electrostatic protection element is connected to the common end.

The present invention also provides a control circuit with electrostatic protection, including: multiple shift registers; multiple buses, coupled to the multiple shift registers; a common terminal; a group of electrostatic protection components, coupled to the multiple A set of buses for protecting the plurality of buses from electrostatic current damage; and a set of discharge paths coupled between the set of electrostatic protection components and the common terminal for providing discharge paths to the electrostatic current, wherein The set of ESD protection components includes: a plurality of first ESD protection components coupled to the plurality of buses, the set of discharge paths includes a first discharge path coupled to the plurality of first ESD protection components and the common end; and A plurality of second ESD protection elements are coupled to the plurality of buses, and the set of discharge paths further includes a second discharge path coupled to the plurality of second ESD protection elements and the common end.

The present invention also provides a liquid crystal display with an electrostatic protection control circuit, comprising a first glass substrate, including a plurality of control circuits; a plurality of buses, coupled to the plurality of control circuits; a common terminal; a group of electrostatic protection components , a group of buses coupled to the plurality of buses, used to protect the plurality of control circuits from being damaged by electrostatic current; and a group of discharge paths, coupled to the group of electrostatic protection components and the common terminal, to provide discharge path for electrostatic current; wherein the common end is used to discharge the electrostatic current transmitted through the group of discharge paths; a second glass substrate; and a liquid crystal layer, the liquid crystal layer is interposed between the first glass substrate and the second glass Between the substrates, wherein the group of electrostatic protection components includes: a first electrostatic protection component coupled to a first bus of the plurality of buses, and the group of discharge paths includes a first discharge path coupled to the first static electricity A protection element and the common end; and a second ESD protection element coupled to the first bus, and the set of discharge paths further includes a second discharge path coupled to the second ESD protection element and the common end.

The present invention also provides a liquid crystal display with an electrostatic protection control circuit, comprising: a first glass substrate, including: a plurality of control circuits; a plurality of buses, coupled to the plurality of control circuits; a common terminal; A protection element, coupled to a group of buses of the plurality of buses, used to protect the plurality of buses from being damaged by electrostatic current; and a set of discharge paths, coupled to the group of electrostatic protection elements and the common end, for providing Discharge path for electrostatic current; wherein the common end is used to discharge the electrostatic current transmitted through the group of discharge paths; a second glass substrate; and a liquid crystal layer, the liquid crystal layer is between the first glass substrate and the second Between the glass substrates, the group of ESD protection components includes: a plurality of first ESD protection components coupled to the plurality of buses, and the group of discharge paths includes a first discharge path coupled to the plurality of first ESD protection components components and the common end; and a plurality of second electrostatic protection elements coupled to the plurality of buses, the set of discharge paths also includes a second discharge path coupled to the plurality of second electrostatic protection elements and the common end .

Description of drawings

FIG. 1 is a schematic diagram of a liquid crystal display.

FIG. 2 is a schematic diagram of a glass substrate.

FIG. 3 is a schematic diagram of a glass substrate in the prior art.

FIG. 4 is a schematic diagram of a glass substrate in the prior art.

FIG. 5 is a schematic diagram of the control circuit with electrostatic protection of the present invention.

FIG. 6 is a schematic diagram of a glass substrate with electrostatic protection according to the present invention.

FIG. 7 is a schematic diagram of another control circuit with electrostatic protection according to the present invention.

FIG. 8 is a schematic diagram of another glass substrate with electrostatic protection according to the present invention.

FIG. 9 is a schematic diagram of the electrostatic protection component of the present invention.

Description of reference symbols

100 LCD display

110130330400600800 glass substrate

120 Liquid crystal layer

210411811 Pixel area

Q1 Thin Film Transistor

C1 Storage capacitor

VCOM VA Vx common terminal

E1-En ESD Protection Components

410610810 Pixel Module

420520720 Shift register module

430510710 Bus module

412530540612730740812 Static protection module

S1～Sn Shift register

ST Start signal

B1-B9 Bus

VSS Bias

XCK CK clock signal

P1P2P3P4 Discharge path

500700 Control circuit

501502701 Electrostatic discharge event

Detailed ways

Please refer to Figure 5. FIG. 5 is a schematic diagram of a control circuit 500 with electrostatic protection according to the present invention. As shown in the figure, the control circuit 500 with ESD protection includes a bus module 510, a shift register module 520, two ESD protection modules 530 and 540, two discharge paths P1 and P2, and a common terminal Vx. The bus module 510 includes buses B4 , B5 , and B6 , which are respectively used to provide the bias voltage VSS and the clock signals XCK and CK to the shift register module 520 . The shift register module 520 includes a plurality of shift registers S1˜Sn, and each shift register has a corresponding gate line. The first shift register S1 is used to receive the start signal ST, and then send the gate signal to the first gate line, and the subsequent shift register S2 sends the gate signal to the corresponding gate line in sequence according to the first gate signal The gate lines are deduced by analogy until the Sn outputs the nth gate signal to complete the scanning of a page. The ESD protection module 530 includes three ESD protection components E7 , E8 , E9 respectively coupled to the buses B4 , B5 , and B6 to protect the buses B4 ˜ B6 from being damaged by ESD events. The ESD protection module 540 includes three ESD protection elements E10, E11, and E12, respectively coupled to the buses B4, B5, and B6 and maintaining a fixed distance from the protection module 530 to protect the buses B4-B6 from ESD damage. The discharge paths P1 and P2 are respectively coupled to the ESD protection modules 530 and 540 for providing a path for the ESD current to flow. The common terminal Vx is coupled to the discharge paths P1 and P2 for dissipating the flowing electrostatic discharge current. For example, in a normal state, the ESD protection module 530 is in an off state, and for the bus B4, the ESD protection element E7 is also in an off state, therefore, it will not affect the normal operation of the bus B4. And when an electrostatic discharge event 501 occurs on the upper end of the bus B4, the electrostatic protection element E7 is turned on, conducting the electrostatic discharge current to the discharge path P1, and then releasing the electrostatic discharge current through the common terminal Vx, thereby protecting the bus B4. For another example, when the ESD event 502 occurs at the lower end of the bus B4, the ESD protection element E10 is turned on, and conducts the ESD current to the discharge path P2, and then discharges the ESD current through the common terminal Vx, thereby protecting the bus B4. In fact, the placement of the ESD protection modules 530 and 540 is not absolutely located at the upper or lower end of the bus module, and they are placed according to the consideration of the circuit layout. The ESD protection modules are not limited to two groups, or may be multiple groups, which are designed according to the consideration of circuit layout.

Please refer to Figure 6. FIG. 6 is a schematic diagram of a glass substrate 600 with electrostatic protection according to the present invention. The glass substrate 600 includes a pixel module 610 and a control circuit 500 . The pixel module 610 includes a plurality of pixel regions and an electrostatic protection module 612 . The design of the pixel module 610 can be simulated to that of the pixel module 410 , and a plurality of horizontal gate lines and a plurality of vertical source lines intersect to form a plurality of pixel regions, as shown in the pixel region 611 . The ESD protection module 612 includes a plurality of ESD protection elements E13˜En and a common terminal VA. The common terminal Vx in the control circuit 500 can be coupled to the common terminal VCOM of the pixel module 610, or to the common terminal VA of the electrostatic protection module 612, so that when an electrostatic discharge event occurs on the bus module 510, the electrostatic discharge The current can pass through the ESD protection module 530 or 540 , flow through the discharge path P1 or P2 respectively, then flow to the common terminal Vx, and finally dissipate through the common terminal VCOM or VA, so as to protect the bus module 510 .

Please refer to Figure 7. FIG. 7 is a schematic diagram of another control circuit 700 with electrostatic protection according to the present invention. As shown in the figure, the control circuit 700 with ESD protection includes a bus module 710, a shift register module 720, two ESD protection modules 730 and 740, two ESD protection elements E21 and E22, two discharge paths P3 and P4, and a common Terminal Vx. The bus module 710 includes buses B7 , B8 , and B9 , which are respectively used to provide the bias voltage VSS and the clock signals XCK and CK to the shift register module 720 . The shift register module 720 includes a plurality of shift registers S1˜Sn, and each shift register has a corresponding gate line. The first shift register S1 is used to receive the start signal ST, and then send the gate signal to the first gate line, and the subsequent shift register S2 sends the gate signal to the corresponding gate line in sequence according to the first gate signal The gate lines are deduced by analogy until the Sn outputs the nth gate signal to complete the scanning of a page. The ESD protection module 730 includes three ESD protection elements E15 , E16 , E17 respectively coupled to the upper ends of the buses B7 , B8 , and B9 to protect the buses B7 ˜ B9 from being damaged by ESD events. The ESD protection module 740 includes three ESD protection elements E18 , E19 , E20 respectively coupled to the lower ends of the buses B7 , B8 , and B9 to protect the buses B7 ˜ B9 from being damaged by ESD events. The discharge paths P3 and P4 are respectively coupled to the ESD protection modules 730 and 740 for providing a path for the ESD current to flow. The common terminal Vx is respectively coupled to the discharge paths P3 and P4 via the ESD protection elements E22 and E21 for dissipating the flowing ESD current. The control circuit 700 is similar to the control circuit 500, the only difference is that the control circuit 700 has two more electrostatic protection elements E21 and E22 between the discharge paths P3, P4 and the common terminal Vx. Its purpose is that if the electrostatic discharge event 701 occurs at the intersection A in FIG. Vx provides a fixed voltage level, but will pull the clock signal XCK on the bus B8, causing malfunction. However, if an electrostatic protection element E21 is added between the discharge path P3 and the common terminal Vx, after the cross point A is broken through, although the bus B8 and the discharge path P3 are short-circuited, due to the relationship between the electrostatic protection element E21, the bus B8 is not directly coupled to the common terminal Vx, and under normal conditions, the ESD protection element E21 is in a disconnected state. Therefore, under normal conditions, the bus B8 can still operate normally to transmit the clock signal XCK. The same situation is also applicable when the ESD event 701 occurs at the intersections B, C, and D, and the ESD protection elements E21 and E22 can also be used to keep the buses B7-B9 still operating normally. In addition, the intersection points A~D only indicate that the discharge path crosses the bus line, and there is no coupling relationship under normal conditions. The discharge path P3 is horizontally routed on the second layer of the wiring layer. There is no actual coupling due to the different layers. When the electrostatic discharge event occurs at the intersection A of the bus B8, if the intersection A is broken through, then It will still cause a short circuit between the bus B8 of the first wiring layer and the discharge path P3 of the second wiring layer. In fact, the placement of the ESD protection modules 730 and 740 is not absolutely located at the upper end or lower end of the bus module, but is placed according to the consideration of the circuit layout. The ESD protection module is not limited to two groups, or may be multiple groups, and is also designed according to the consideration of circuit layout.

Please refer to Figure 8. FIG. 8 is a schematic diagram of a glass substrate 800 with electrostatic protection according to the present invention. The glass substrate 800 includes a pixel module 810 and a control circuit 700 . The pixel module 810 includes a plurality of pixel regions and an electrostatic protection module 812 . The design of the pixel module 810 can be simulated to that of the pixel module 410 , and a plurality of horizontal gate lines and a plurality of vertical source lines intersect to form a plurality of pixel regions, as shown in the pixel region 811 . The ESD protection module 812 includes a plurality of ESD protection elements E23˜En and a common terminal VA. The common terminal Vx in the control circuit 700 can be coupled with the common terminal VCOM of the pixel module 810, or coupled with the common terminal VA of the electrostatic protection module 812, so that when an electrostatic discharge event occurs on the bus module 710, the electrostatic discharge The current can pass through the ESD protection module 730 or 740, flow through the discharge path P3 or P4 respectively, then pass through the ESD protection components E22 and E21, flow to the common terminal Vx, and finally dissipate through the common terminal VCOM or VA, so as to achieve protection The purpose of the bus module 710.

Please refer to Figure 9. FIG. 9 is a schematic diagram of an electrostatic protection component 900 of the present invention. The ESD protection component 900 can be formed by coupling diodes D1 and D2 back to back, or other components that can protect circuit components from ESD events.

To sum up, through the design of the electrostatic protection circuit of the present invention, the electrostatic discharge event can be effectively resisted during the production of the glass substrate, so that the relevant signal routing of the control circuit on the glass substrate can be free from the electrostatic discharge event damage, thereby increasing the pass rate of production. However, the electrostatic protection circuit designed by the present invention is not limited to be applied to glass substrates and liquid crystal displays. Other circuit designs can use the spirit of the present invention to realize electrostatic protection with electrostatic protection components, discharge paths, and common terminals. purpose of protection.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the present invention.

Claims (18)

1. A control circuit with electrostatic protection, comprising: multiple shift registers; a plurality of buses, coupled to the plurality of shift registers; a common terminal; a set of electrostatic protection components, coupled to a set of buses of the plurality of buses, to protect the plurality of buses from being damaged by electrostatic current; and A set of discharge paths, coupled to the set of electrostatic protection components and the common end, to provide discharge paths for electrostatic currents, Among them, the group of electrostatic protection components includes: A first ESD protection component coupled to a first bus of the plurality of buses, the set of discharge paths includes a first discharge path coupled to the first ESD protection component and the common end; and A second ESD protection component is coupled to the first bus, and the set of discharge paths further includes a second discharge path, coupled to the second ESD protection component and the common end. 2. The control circuit as claimed in claim 1 , further comprising a third ESD protection element coupled between the second discharge path and the common terminal. 3. The control circuit as claimed in claim 1 , further comprising a fourth electrostatic protection element coupled between the first discharge path and the common terminal. 4. The control circuit according to claim 1, wherein the group of electrostatic protection components is a group of diodes connected in antiparallel to each other. 5. A control circuit with electrostatic protection, comprising: multiple shift registers; a plurality of buses, coupled to the plurality of shift registers; a common terminal; a set of electrostatic protection components, coupled to a set of buses of the plurality of buses, to protect the plurality of buses from being damaged by electrostatic current; and A set of discharge paths, coupled to the set of electrostatic protection components and the common end, to provide discharge paths for electrostatic currents, Among them, the group of electrostatic protection components includes: A plurality of first ESD protection components coupled to the plurality of buses, the group of discharge paths includes a first discharge path coupled to the plurality of first ESD protection components and the common end; and A plurality of second ESD protection elements are coupled to the plurality of buses, and the set of discharge paths further includes a second discharge path coupled to the plurality of second ESD protection elements and the common terminal. 6. The control circuit as claimed in claim 5 , further comprising a third ESD protection element coupled between the second discharge path and the common terminal. 7. The control circuit as claimed in claim 5 , further comprising a fourth electrostatic protection element coupled between the first discharge path and the common terminal. 8. The control circuit according to claim 5, wherein the group of electrostatic protection components is a group of diodes connected in antiparallel to each other. 9. A liquid crystal display with an electrostatic protection control circuit, comprising: A first glass substrate, comprising: Multiple control circuits; Multiple buses, coupled to the multiple control circuits; a common terminal; a set of electrostatic protection components, coupled to a set of buses of the plurality of buses, to protect the plurality of buses from being damaged by electrostatic current; and A set of discharge paths, coupled to the set of electrostatic protection components and the common end, to provide discharge paths for electrostatic currents; Wherein the common terminal is used to discharge the electrostatic current transmitted through the set of discharge paths; a second glass substrate; and a liquid crystal layer, the liquid crystal layer is interposed between the first glass substrate and the second glass substrate, Among them, the group of electrostatic protection components includes: A first ESD protection component coupled to a first bus of the plurality of buses, the set of discharge paths includes a first discharge path coupled to the first ESD protection component and the common end; and A second ESD protection component is coupled to the first bus, and the set of discharge paths further includes a second discharge path, coupled to the second ESD protection component and the common end. 10. The liquid crystal display as claimed in claim 9, wherein the first glass substrate further comprises a third electrostatic protection element coupled between the second discharge path and the common terminal. 11. The liquid crystal display as claimed in claim 9, wherein the first glass substrate further comprises a fourth electrostatic protection element coupled between the first discharge path and the common terminal. 12. The liquid crystal display as claimed in claim 9, wherein the plurality of control circuits are a plurality of shift registers. 13. The liquid crystal display as claimed in claim 9, wherein the group of electrostatic protection components is a group of diodes connected in antiparallel to each other. 14. A liquid crystal display with an electrostatic protection control circuit, comprising: A first glass substrate, comprising: Multiple control circuits; Multiple buses, coupled to the multiple control circuits; a common terminal; a set of electrostatic protection components, coupled to a set of buses of the plurality of buses, to protect the plurality of buses from being damaged by electrostatic current; and A set of discharge paths, coupled to the set of electrostatic protection components and the common end, to provide discharge paths for electrostatic currents; Wherein the common terminal is used to discharge the electrostatic current transmitted through the set of discharge paths; a second glass substrate; and a liquid crystal layer, the liquid crystal layer is interposed between the first glass substrate and the second glass substrate, Among them, the group of electrostatic protection components includes: A plurality of first ESD protection components coupled to the plurality of buses, the group of discharge paths includes a first discharge path coupled to the plurality of first ESD protection components and the common end; and A plurality of second ESD protection elements are coupled to the plurality of buses, and the set of discharge paths further includes a second discharge path coupled to the plurality of second ESD protection elements and the common terminal. 15. The liquid crystal display as claimed in claim 14 , wherein the first glass substrate further comprises a third electrostatic protection element coupled between the second discharge path and the common terminal. 16. The liquid crystal display as claimed in claim 14 , wherein the first glass substrate further comprises a fourth electrostatic protection element coupled between the first discharge path and the common terminal. 17. The liquid crystal display as claimed in claim 14, wherein the plurality of control circuits are a plurality of shift registers. 18. The liquid crystal display as claimed in claim 14, wherein the group of electrostatic protection components is a group of diodes connected in antiparallel to each other.

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