Display device

Abstract

To maintain display on an entire display panel even with single-side gate driving.SOLUTION: A display device (1) is provided, comprising a display panel (2) including a first gate drive circuit (4) and a second gate drive circuit (5) arranged on respective sides of a pixel array (3), a first protection circuit (6) for detecting first overcurrent supplied to the first gate drive circuit (4), and a second protection circuit (7) for detecting second overcurrent supplied to the second gate drive circuit (5).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a display device including a protection circuit that protects, from overcurrent, the gate drive circuits of a double-sided gate-driven GOA (Gate on Array) panel that drives a pixel array by gate drive circuits arranged on both sides of the pixel array. [Background technology]

[0002] A protection circuit is known in which an overcurrent detector is connected to both the high-voltage side and the low-voltage side switching transistors, and a counter that counts the number of times an overcurrent is detected outputs a shutdown signal to shut down the driver circuit when the counter detects an overcurrent a specified number of times (2 or more) (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-016577 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a double-sided gate drive GOA panel, in which the pixel array is driven by gate drive circuits arranged on both sides of the pixel array, if a malfunction occurs in the gate drive circuit on one side of the pixel array, an overcurrent will flow, and the gate voltage of the gate drive circuits on both sides of the display panel will be shut down by the overcurrent limiting function of the power management IC (PMIC (Power management integrated circuit)) and level shifter on the timing control (TCON) board. This causes the display of the entire display panel to disappear, making it difficult to find the cause of the malfunction in the gate drive circuit.

[0005] One embodiment of the present disclosure aims to realize a display device that can maintain display even after an overcurrent flows in one of the gate drive circuits in a double-sided gate drive GOA panel. [Means for solving the problem]

[0006] In order to solve the above problems, a display device according to one embodiment of the present disclosure includes a display panel including a pixel array including a plurality of pixels, a plurality of gate bus lines connected to the pixel array, a first gate drive circuit arranged on one side of the pixel array and supplying scanning signals to the plurality of gate bus lines, and a second gate drive circuit arranged on the opposite side of the pixel array from the first gate drive circuit and supplying scanning signals to the plurality of gate bus lines, a first protection circuit that detects a first overcurrent supplied to the first gate drive circuit and protects the first gate drive circuit from the first overcurrent, and a second protection circuit that is a circuit separate from the first protection circuit and detects a second overcurrent supplied to the second gate drive circuit and protects the second gate drive circuit from the second overcurrent. Effect of the Invention

[0007] According to one aspect of the present disclosure, in a double-sided gate-driven GOA panel, display can be maintained even after an overcurrent flows in one of the gate drive circuits. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of a display device according to a first embodiment. [Diagram 2] 4 is a circuit diagram of a first protection circuit provided in the display device. FIG. [Diagram 3] 10 is a circuit diagram of a first protection circuit provided in a display device according to a second embodiment. FIG. [Figure 4] 4 is a waveform diagram showing a current flowing through a gate clock wiring during normal operation of the display device. FIG. [Diagram 5] 11 is a waveform diagram showing an overcurrent flowing through the gate clock wiring. FIG. [Figure 6] 11 is a circuit diagram of a first protection circuit provided in a display device according to Embodiment 3. FIG. [Figure 7] 11 is a waveform diagram showing a peak current flowing through a gate clock wiring. FIG. [Figure 8] FIG. 11 is a circuit diagram of a first protection circuit provided in a display device according to Embodiment 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Embodiment 1] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present disclosure will be described in detail below. Fig. 1 is a schematic diagram of a display device 1 according to a first embodiment.

[0010] The display device 1 includes a display panel 2. The display panel 2 includes a pixel array 3 including a plurality of pixels PX, a plurality of gate bus lines GL connected to the pixel array 3, a first gate drive circuit 4 disposed on one side of the pixel array 3 and supplying scanning signals to the plurality of gate bus lines GL, and a second gate drive circuit 5 disposed on the opposite side of the pixel array 3 from the first gate drive circuit 4 and supplying scanning signals to the plurality of gate bus lines GL.

[0011] The scanning signals are signals applied from the first gate drive circuit 4 and the second gate drive circuit 5 to the gate bus lines GL in order to sequentially select the gate bus lines GL.

[0012] The display device 1 further includes a first protection circuit 6 that detects a first overcurrent supplied to the first gate drive circuit 4 and protects the first gate drive circuit 4 from the first overcurrent, and a second protection circuit 7 that is separate from the first protection circuit 6 and detects a second overcurrent supplied to the second gate drive circuit 5 and protects the second gate drive circuit 5 from the second overcurrent.

[0013] The first overcurrent is a current flowing toward the first gate drive circuit 4 to operate the first gate drive circuit 4, and is a current that exceeds a current value allowed by the first gate drive circuit 4. The second overcurrent is a current flowing toward the second gate drive circuit 5 to operate the second gate drive circuit 5, and is a current that exceeds a current value allowed by the second gate drive circuit 5. The allowable current value of the first gate drive circuit 4 and the allowable current value of the second gate drive circuit 5 may be the same or different.

[0014] Thus, the display device 1 has a display panel 2 that is a double-sided gate-driven GOA panel. The GOA panel is a display panel having a gate driver function on a glass substrate. The display device 1 includes a first protection circuit 6 that detects a first overcurrent supplied to the first gate drive circuit 4 and protects the first gate drive circuit 4 from the first overcurrent, and a second protection circuit 7 that detects a second overcurrent supplied to the second gate drive circuit 5 and protects the second gate drive circuit 5 from the second overcurrent. The first protection circuit 6 and the second protection circuit 7 are separate circuits.

[0015] The display device 1 further includes a protection circuit connecting wire 8 that connects the first protection circuit 6 and the second protection circuit 7 and receives a notification signal that notifies of the detection of the first overcurrent or the second overcurrent.

[0016] When the first protection circuit 6 detects a first overcurrent, a notification signal notifying the detection of the first overcurrent is supplied by the first protection circuit 6 to the protection circuit connecting wiring 8. Then, the second protection circuit 7 receives the notification signal supplied by the first protection circuit 6 through the protection circuit connecting wiring 8, thereby notifying the second protection circuit 7 that the first overcurrent has been detected by the first protection circuit 6 (and that the first overcurrent supplied to the first gate drive circuit 4 has been cut off).

[0017] The opposite occurs when the second protection circuit 7 detects a second overcurrent. That is, a notification signal notifying the detection of a second overcurrent is supplied by the second protection circuit 7 to the protection circuit connecting wiring 8. Then, the first protection circuit 6 receives the notification signal supplied by the second protection circuit 7 through the protection circuit connecting wiring 8, thereby notifying the first protection circuit 6 that the second overcurrent has been detected by the second protection circuit 7 (and that the second overcurrent supplied to the second gate drive circuit 5 has been cut off).

[0018] The first protection circuit 6 switches the setting value in the first protection circuit 6 in response to receiving the notification signal. In this embodiment, the first protection circuit 6 switches the threshold value for detecting a first overcurrent in response to receiving the notification signal. The threshold value for detecting an overcurrent (hereinafter also referred to as the "overcurrent detection threshold value") is one of the setting values ​​in the first and second protection circuits 6 and 7.

[0019] For example, the first protection circuit 6 and the second protection circuit 7 are connected by a protection circuit connecting wire 8, and the protection circuit connecting wire 8 is pulled up. When one of the first protection circuit 6 and the second protection circuit 7 detects an overcurrent, that one protection circuit stops supplying current to the gate drive circuit and supplies a notification signal (a low-level signal in this embodiment) to the protection circuit connecting wire 8. The other protection circuit of the first protection circuit 6 and the second protection circuit 7 switches the overcurrent protection setting in response to receiving the notification signal (i.e., a low-level signal is supplied to the protection circuit connecting wire 8).

[0020] The display device 1 further includes a plurality of source bus lines SL connected to the pixel array 3, a source driving circuit 14 that supplies video signals to the plurality of source bus lines SL, and a source substrate 12 that is connected to the display panel 2 via a flexible circuit board 13 on which the source driving circuit 14 is provided. The first protection circuit 6 and the second protection circuit 7 are disposed on the source substrate 12.

[0021] 1, when the display device 1 includes a plurality of source substrates 12 connected to the display panel 2 via a plurality of flexible circuit substrates 13, for example, the first protection circuit 6 is disposed on one of the plurality of source substrates 12, and the second protection circuit 7 is disposed on another of the plurality of source substrates 12. The display device 1 includes a control substrate 9 connected to each of the plurality of source substrates 12 via an FFC (flexible flat cable).

[0022] 1, the protection circuit connection wiring 8 is connected from the first protection circuit 6 to the second protection circuit 7 via one source substrate 12, an FFC connected to the one source substrate 12, the control substrate 9, an FFC connected to the other source substrate, and the other source substrate 12 in this order. Note that when the display device 1 is provided with only one source substrate 12, the first protection circuit 6 and the second protection circuit 7 are disposed on the same source substrate 12.

[0023] If the display panel 2 is hit during the manufacturing process of the display device 1, causing chips in the first and second gate drive circuits 4·5, or if dust or other particles get in during the TFT process and cause dielectric breakdown of the insulating film over time, causing a short circuit in the first and second gate drive circuits 4·5, an overcurrent will occur in the first and second gate drive circuits 4·5.

[0024] Conventionally, an overcurrent protection circuit (power management IC (PMIC) 15 on the control board 9 or an overcurrent limiting function of a level shifter) was used, which was connected to both the first gate drive circuit 4 and the second gate drive circuit 5 to protect them from overcurrent. For this reason, when an overcurrent occurs in either the first gate drive circuit 4 or the second gate drive circuit 5, the entire pixel array 3 is shut down, and the display panel 2 cannot continue displaying.

[0025] In contrast, the display device 1 of this embodiment has separate overcurrent protection circuits for the first gate drive circuit 4 and the second gate drive circuit 5. Therefore, according to this embodiment, when an overcurrent occurs in one of the gate drive circuits, the current supply to only that one gate drive circuit can be stopped, and the display on the display panel 2 can be continued using the other gate drive circuit.

[0026] Furthermore, in general, when the display device 1 that was originally double-sided gate driven becomes single-sided gate driven (gate driven by one gate drive circuit provided on either the left or right side of the display panel 2), the load on the (normal) gate drive circuit that drives the pixel array 3 increases, and the current flowing through that gate drive circuit may increase. For this reason, if the overcurrent protection circuit of one of the gate drive circuits operates with the overcurrent protection setting value for double-sided gate drive remaining, the current flowing through the gate drive circuit on that side may increase, and the overcurrent protection circuit may determine that increased current as an overcurrent.

[0027] However, in this embodiment, when an overcurrent protection circuit (e.g., the first protection circuit 6) of one gate drive circuit detects an overcurrent and performs a circuit protection operation (stopping the current supply), the detection of the overcurrent can be notified to an overcurrent protection circuit (e.g., the second protection circuit 7) of the other gate drive circuit via the protection circuit connection wiring 8, and the setting of the overcurrent protection circuit of the other gate drive circuit can be switched. For example, the overcurrent detection threshold of the overcurrent protection circuit of the other gate drive circuit can be increased. Therefore, the other gate drive circuit can be appropriately protected in consideration of the fluctuation of its load, and the pixel array 3 can be stably driven by the other gate drive circuit.

[0028] 2 is a circuit diagram of the first protection circuit 6 provided in the display device 1. Components similar to those described above are given the same reference numerals. Detailed descriptions of these components will not be repeated. The second protection circuit 7 is configured similarly to the first protection circuit 6.

[0029] The first protection circuit 6 and / or the second protection circuit 7 includes transistors T1, T2, ..., Tn connected to the input wirings IN1, IN2, ..., INn and the output wirings OUT1, OUT2, ..., OUTn, respectively, current detection circuits K1, K2, ..., Kn connected to the transistors T1, T2, ..., Tn, respectively, and a control circuit 16 that controls the transistors T1, T2, ..., Tn in response to the outputs of the current detection circuits K1, K2, ..., Kn.

[0030] In this way, the first protection circuit 6 is connected to a plurality of input / output wirings IN1, IN2, ..., INn, OUT1, OUT2, ..., OUTn, as shown in FIG. 2. The first protection circuit 6 has transistors T1, T2, ..., Tn between the input wirings IN1, IN2, ..., INn and the output wirings OUT1, OUT2, ..., OUTn, and is capable of cutting off a first overcurrent occurring in the input wirings IN1, IN2, ..., INn. The voltage between the source and drain of the transistors T1, T2, ..., Tn is used to detect the current. When the voltage output by the current detection circuits K1, K2, ..., Kn becomes higher than the reference voltage output by the current limit setting circuit 17, the control circuit 16 closes the gates of the transistors T1, T2, ..., Tn to cut off the first overcurrent occurring in the input wirings IN1, IN2, ..., INn.

[0031] The multiple input / output wirings IN1, IN2, ..., INn, OUT1, OUT2, ..., OUTn correspond to wirings (hereinafter referred to as "gate control wirings 18") for inputting various signals (clock signals, reference voltage signals, etc.) from the timing controller 10 to the first or second gate drive circuit 4·5, i.e., wirings extending from the timing controller 10 shown in Fig. 1 to the first or second gate drive circuit 4·5. Also, in Fig. 1, only one gate control wiring 18 is depicted to simplify the illustration and make it easier to understand, but in reality, there are multiple gate control wirings arranged in parallel with each other, as shown in Fig. 2.

[0032] At this time, the control circuit 16 cuts off the first overcurrent in all the input wirings IN1, IN2, . . . , INn if any one of the current detection circuits K1, K2, .

[0033] When an overcurrent occurs in the first gate drive circuit 4, the potential difference between the source and drain of the transistors T1, T2, ..., Tn of the first protection circuit 6 increases and exceeds the overcurrent detection threshold of the first protection circuit 6. The control circuit 16 of the first protection circuit 6 detects a first overcurrent based on the fact that the voltage received from the current detection circuits K1, K2, ..., Kn (a voltage representing the potential difference between the source and drain of the transistors T1, T2, ..., Tn of the first protection circuit 6) becomes higher than the reference voltage output from the current limit setting circuit 17 (the overcurrent detection threshold of the first protection circuit 6), and closes the gates of the transistors T1, T2, ..., Tn of the first protection circuit 6 to cut off the first overcurrent.

[0034] The second protection circuit 7 is similar to the first protection circuit 6. That is, when an overcurrent occurs in the second gate drive circuit 5, the potential difference between the source and drain of the transistors T1, T2, ..., Tn of the second protection circuit 7 increases and exceeds the overcurrent detection threshold of the second protection circuit 7. The control circuit 16 of the second protection circuit 7 detects a second overcurrent based on the fact that the voltage received from the current detection circuits K1, K2, ..., Kn (a voltage representing the potential difference between the source and drain of the transistors T1, T2, ..., Tn of the second protection circuit 7) becomes higher than the reference voltage output from the current limit setting circuit 17 (the overcurrent detection threshold of the second protection circuit 7), and closes the gates of the transistors T1, T2, ..., Tn of the second protection circuit 7 to cut off the second overcurrent.

[0035] The reference voltage is a voltage corresponding to a threshold selected by the current limit setting circuit 17 from the thresholds LIM1_SET and LIM2_SET for detecting an overcurrent in accordance with the level of the notification signal of the input / output terminal BK_SEL.

[0036] A first resistor corresponding to the threshold value LIM1_SET and a second resistor corresponding to the threshold value LIM2_SET are connected to the current limit setting circuit 17. The reference voltage output by the current limit setting circuit 17 can be determined by the resistance values ​​of the first resistor and the second resistor.

[0037] The current limit setting circuit 17 has an open-drain input / output terminal BK_SEL. The input / output terminal BK_SEL of the current limit setting circuit 17 of the first protection circuit 6 and the input / output terminal BK_SEL of the current limit setting circuit 17 of the second protection circuit 7 are connected by a protection circuit connecting wiring 8. The current limit setting circuit 17 outputs a low-level signal (notification signal) to the protection circuit connecting wiring 8 through the input / output terminal BK_SEL when the control circuit 16 detects an overcurrent and cuts it off.

[0038] During normal operation when the control circuit 16 is not detecting an overcurrent, the potential of the protection circuit connecting wiring 8 is maintained at a high level. At this time, both the first protection circuit 6 and the second protection circuit 7 perform overcurrent protection using the threshold value LIM1_SET as the overcurrent detection threshold value. Then, for example, when the first protection circuit 6 detects a first overcurrent and its current limit setting circuit 17 outputs a low-level signal (notification signal) to the protection circuit connecting wiring 8 through the input / output terminal BK_SEL, the second protection circuit 7 changes the overcurrent detection threshold value from the threshold value LIM1_SET to the threshold value LIM2_SET in response to receiving the notification signal, and performs overcurrent protection. Here, the threshold value LIM2_SET is larger than the threshold value LIM1_SET.

[0039] Normally, one-sided gate driving increases the current consumption of the first gate drive circuit 4 or the second gate drive circuit 5. For this reason, resistance values ​​corresponding to the thresholds LIM1_SET and LIM2_SET are determined so that the reference voltage corresponding to the threshold LIM2_SET is higher than the reference voltage corresponding to the threshold LIM1_SET.

[0040] By setting in this way, it is possible to set an optimum overcurrent detection threshold for each state during normal operation of double-sided gate drive when no overcurrent is detected, and during single-sided gate drive after an overcurrent is detected, and it becomes possible to continue driving the first gate drive circuit 4 or the second gate drive circuit 5 even if the current flowing through the first gate drive circuit 4 or the second gate drive circuit 5 increases due to single-sided gate drive. As a result, the display panel 2 can continue to be lit.

[0041] What the first protection circuit 6 or the second protection circuit 7 cuts off is the first overcurrent or the second overcurrent of all signals (gate control signals) supplied to the first gate drive circuit 4 and the second gate drive circuit 5, such as the gate start pulse signal GSP, the gate clock signal GCK, the gate end pulse signal GEP, etc. The other normal gate driver of the first gate drive circuit 4 or the second gate drive circuit 5 continues to operate since the gate control signals continue to be supplied, and although the display on the abnormal gate driver side becomes dark, the display panel 2 as a whole can continue to display.

[0042] The first protection circuit 6 is configured to be able to select a plurality of thresholds including a threshold LIM1_SET (first threshold) and a threshold LIM2_SET (second threshold) higher than the threshold LIM1_SET as a threshold for detecting a first overcurrent, and switches the threshold for detecting the first overcurrent from the threshold LIM1_SET to the threshold LIM2_SET in response to receiving the notification signal "L". The second protection circuit 7 is configured to be able to select a plurality of thresholds including a threshold LIM1_SET (third threshold) and a threshold LIM2_SET (fourth threshold) higher than the threshold LIM1_SET as a threshold for detecting a second overcurrent, and switches the threshold for detecting the second overcurrent from the threshold LIM1_SET to the threshold LIM2_SET in response to receiving the notification signal "L". The first threshold and the third threshold may be the same or different. Similarly, the second threshold and the fourth threshold may be the same or different.

[0043] As cases in which this embodiment is used, other than when a problem occurs in the manufacturing process of the display device 1 and the cause of the problem is to be investigated, the following cases are conceivable. Cases where a malfunction occurs due to aging of the display device 1, and the display suddenly disappears, causing inconvenience. The gate drive circuit on the defective side is separated (and resized) from the display panel using laser processing or other methods, and used as a display panel with single-sided gate drive.

[0044] Even when driving one side of the gate to find the cause of the malfunction, the gate drive circuit on the driving side needs to have an overcurrent protection circuit for the following reasons.

[0045] If there is no overcurrent protection circuit during testing to find the cause of the malfunction, the overcurrent protection circuit provided in the power management IC 15 will activate and cut off the voltage to not only the gate drive circuit but also the source drive circuit 14. This will cause nothing to be displayed on the display panel 2, making it difficult to find the cause of the malfunction. By installing an overcurrent protection circuit in front of each of the left and right gate drive circuits, the overcurrent protection circuit on the defective side will activate and stop the output to the defective gate drive circuit, causing the display on the defective side to go dark. This makes it possible to identify that the cause of the malfunction is in the gate drive circuit on the side with the dark display.

[0046] Furthermore, when lighting a display panel 2 with a faulty gate drive circuit on one side, the overcurrent protection circuit in front of the normal gate drive circuit cuts off the overcurrent of the gate control signal when a gate control signal with incorrect timing is received, but since the gate control signal reaches just before the overcurrent protection circuit, the cause can be identified by observing the waveform with an oscilloscope. If there is no overcurrent protection circuit, the power management IC 15 stops outputting the gate voltages VGH and VGL, and the gate control signal itself is not output, making it difficult to identify the cause. Note that in this embodiment, the overcurrent protection circuit for the gate voltages VGH and VGL provided in the power management IC 15 is not an essential component.

[0047] The display device 1 is further provided with a third protection circuit arranged on a control board 9 on which a timing controller 10 for controlling the operation timing of the first gate drive circuit 4 and the second gate drive circuit 5 is provided, and which detects the first overcurrent and the second overcurrent to protect the first gate drive circuit 4 and the second gate drive circuit 5 from the first overcurrent and the second overcurrent. The third protection circuit may correspond to an overcurrent protection circuit provided in a level shifter or a power management IC 15. In the following, a case where the third protection circuit corresponds to an overcurrent protection circuit provided in a level shifter will be described as an example.

[0048] The third protection circuit 11 operates as a level shifter, and is connected to the first gate drive circuit 4 via the gate control wiring 18 and the first protection circuit 6, and is connected to the second gate drive circuit 5 via the gate control wiring 18 and the second protection circuit 7.

[0049] The threshold for detecting the first overcurrent in the third protection circuit 11 is higher than the threshold for detecting the first overcurrent in the first protection circuit 6, and the threshold for detecting the second overcurrent in the third protection circuit 11 is higher than the threshold for detecting the second overcurrent in the second protection circuit 7.

[0050] According to the above configuration, the threshold value of the first protection circuit 6 and the threshold value of the second protection circuit 7 are lower than the threshold value of the third protection circuit 11, so it is possible to avoid a situation in which the third protection circuit 11 operates before the first protection circuit 6 and the second protection circuit 7, causing the entire display of the display panel 2 to disappear.

[0051] Although an example in which the first protection circuit 6 and the second protection circuit 7 are arranged on the source substrate 12 is shown, the present invention is not limited to this. The first protection circuit 6 and the second protection circuit 7 may be arranged on the control substrate 9.

[0052] When the first protection circuit 6 and the second protection circuit 7 are disposed on the source substrate 12, the thresholds LIM1_SET and LIM2_SET of the first and second protection circuits 6 and 7 can be set by considering only the characteristics of the gate drive circuit on the GOA panel, since the influence of transmission loss and reflection is small on the source substrate 12. Therefore, it is not necessary to determine the thresholds LIM1_SET and LIM2_SET of the first and second protection circuits 6 and 7 by considering a margin for the influence of transmission loss and reflection.

[0053] When the first protection circuit 6 and the second protection circuit 7 are arranged on the control board 9, the first protection circuit 6 and the second protection circuit 7 can be integrated into the one-chip control board 9. Therefore, the protection circuit connecting wire 8 that connects between the first and second protection circuits 6 and 7 can be formed short within the one chip, and the number of terminals required for the connector that connects the control board 9 and the source board 12 does not increase by the amount of the protection circuit connecting wire 8.

[0054] As described above, according to this embodiment, in a double-sided gate drive GOA panel, by adding the first protection circuit 6 and the second protection circuit 7 for overcurrent protection related to the gate control signal on the source substrate 12, even if a malfunction occurs in one of the gate drive circuits of the display panel 2 and an overcurrent flows, the output of the gate drive circuit on the malfunctioning side can be stopped and the normal gate drive circuit can continue to drive the pixel array 3. In addition, by linking the two first and second protection circuits 6 and 7, even if a malfunction occurs in one of the gate drive circuits of the display panel 2 and an overcurrent flows, the overcurrent detection threshold of the protection circuit connected to the normal gate drive circuit can be switched to an appropriate overcurrent detection threshold corresponding to the change in current consumption due to the gate single-sided drive, and the normal gate drive circuit can continue to drive the pixel array 3 appropriately.

[0055] [Embodiment 2] Fig. 3 is a circuit diagram of a first protection circuit 6A provided in a display device according to embodiment 2. Fig. 4 is a waveform diagram showing a normal current I3 flowing through a gate control wiring 18 during normal operation of the display device. Fig. 5 is a waveform diagram showing an overcurrent I4 flowing through a gate control wiring 18. Components similar to those described above are given the same reference symbols, and detailed descriptions thereof will not be repeated. The second protection circuit 7A is configured similarly to the first protection circuit 6A.

[0056] The first protection circuit 6A may further include capacitors C1, C2, . . . , Cn connected in parallel to the transistors T1, T2, .

[0057] A peak current I1 occurs when an input signal input to the input wirings IN1, IN2, . . . , INn rises or falls.

[0058] When capacitors C1, C2, ..., Cn are connected in parallel to the input cutoff transistors T1, T2, ..., Tn provided in the first and second protection circuits 6 and 7 of the first embodiment, the peak current I1 disappears and a gradually increasing current I2 flows instead. During normal operation where an overcurrent is not detected, a normal current I3 flows. During abnormal operation where an overcurrent is detected, an overcurrent I4 larger than the normal current I3 flows.

[0059] If a peak current I1 flows when the input signal rises or falls, this peak current I1 will be detected as an overcurrent. To avoid this, the threshold for detecting an overcurrent must be set higher than the peak current I1.

[0060] In contrast, when the capacitors C1, C2, ..., Cn are provided as in this embodiment, a gradually increasing current I2 much smaller than the peak current I1 flows, so the peak current I1 is not detected as an overcurrent, but the overcurrent I4 is detected, and the threshold for detecting the overcurrent can be set lower than the peak current I1. As a result, as shown in Fig. 5, when there is an overcurrent I4 lower than the peak current I1, the overcurrent I4 of the gate control signal of the input wirings IN1, IN2, ..., INn can be cut off.

[0061] [Embodiment 3] Fig. 6 is a circuit diagram of the first protection circuits 6B and 7B provided in the display device according to the third embodiment. Fig. 7 is a waveform diagram showing the peak current I1 flowing through the gate control wiring 18. Components similar to those described above are given the same reference symbols. Detailed descriptions of these components will not be repeated. The second protection circuit 7B is configured similarly to the first protection circuit 6B.

[0062] The first protection circuit 6B may further include peak current cutoff transistors PT1, PT2, . . . , PTn connected in series to the capacitors C1, C2, . . . , Cn, respectively.

[0063] In the case of the second embodiment which does not include the peak current cutoff transistors PT1, PT2, . . . , PTn, as shown in FIG. 7, the peak current I1 leaks even after an overcurrent of the gate control signal is detected and cut off.

[0064] However, according to this embodiment, by connecting peak current cutoff transistors PT1, PT2, ..., PTn to the peak current bypass capacitors C1, C2, ..., Cn, respectively, it is possible to cut off the peak current I1 after cutting off the overcurrent of the gate control signal.

[0065] [Embodiment 4] 8 is a circuit diagram of a first protection circuit 6C provided in a display device according to embodiment 4. Components similar to those described above are given the same reference characters, and detailed descriptions thereof will not be repeated. The second protection circuit 7C is configured similarly to the first protection circuit 6C.

[0066] The first protection circuit C may include a register 22 in which a setting value that is switched in response to receiving the notification signal “L” is written. In this manner, the threshold value of the overcurrent protection setting may be replaced by a digital circuit rather than an analog circuit.

[0067] 8 shows an example in which the threshold value of overcurrent protection can be set by the register 22. Writing to the register 22 of the current limit setting circuit 17 is performed according to the I2C (Inter-Integrated Circuit) serial communication standard, and the setting value of the register 22 is stored in an EEPROM (registered trademark) (Electrically Erasable and Programmable Read Only Memory) or a Flash ROM (Read Only Memory).

[0068] [Table 1]

[0069] The register 22 includes registers Clim0 and Clim1 that determine the current threshold at which the first protection circuit 6C for overcurrent protection operates, and registers Tpw0 and Tpw1 that set a peak current ignore period for ignoring the peak current I1. In this way, the setting value of the first protection circuit 6C may include the peak current ignore period in addition to the threshold for overcurrent protection.

[0070] The setting values ​​can be divided between setting Bank0 and setting Bank1. When the notification signal of the protection circuit connection wiring 8 connected to the input / output terminal BK_SEL is "H", the setting value of setting Bank0 is applied, and when the notification signal of the protection circuit connection wiring 8 connected to the input / output terminal BK_SEL is "L", the setting value of setting Bank1 is applied. By making the setting of register Clim1 larger than the setting of register Clim0, the same effect as in embodiment 3 can be achieved.

[0071] In addition, when one-sided gate drive is used, the width of the peak current I1 when the notification signal switches between "H" and "L" also increases, so the setting value of register Tpw1 can be made larger than the setting value of register Tpw0 to keep the setting value of register Clim1 low.

[0072] Since the current at which the first protection circuit 6C for overcurrent protection operates is set by the register value, the set value can be easily changed.

[0073] 〔summary〕 A display device 1 according to a first aspect of the present disclosure includes a display panel 2 including a pixel array 3 including a plurality of pixels PX, a plurality of gate bus lines GL connected to the pixel array 3, a first gate drive circuit 4 arranged on one side of the pixel array 3 and supplying scanning signals to the plurality of gate bus lines GL, and a second gate drive circuit 5 arranged on the opposite side of the pixel array 3 from the first gate drive circuit 4 and supplying scanning signals to the plurality of gate bus lines GL, first protection circuits 6, 6A, 6B, and 6C that detect a first overcurrent supplied to the first gate drive circuit 4 and protect the first gate drive circuit 4 from the first overcurrent, and second protection circuits 7, 7A, 7B, and 7C that are separate from the first protection circuits 6, 6A, 6B, and 6C and that detect a second overcurrent supplied to the second gate drive circuit 5 and protect the second gate drive circuit 5 from the second overcurrent.

[0074] According to the above configuration, a first protection circuit is provided that detects a first overcurrent supplied to the first gate drive circuit and protects the first gate drive circuit from the first overcurrent, and a second protection circuit is provided that is separate from the first protection circuit and detects a second overcurrent supplied to the second gate drive circuit and protects the second gate drive circuit from the second overcurrent. Therefore, when the first protection circuit detects an overcurrent, the first gate drive circuit stops operating, but the second gate drive circuit can continue operating. Therefore, in a double-sided gate drive GOA panel, the display of the entire display panel can be maintained even when driven by a gate drive circuit on one side.

[0075] It is preferable that the display device 1 according to aspect 2 of the present disclosure, in accordance with aspect 1 above, further comprises protection circuit connection wiring 8 which connects the first protection circuits 6, 6A, 6B, 6C and the second protection circuits 7, 7A, 7B, 7C and which receives a notification signal notifying the detection of the first overcurrent or the second overcurrent.

[0076] According to the above configuration, the first protection circuit can notify the second protection circuit of the detection of a first overcurrent, and the second protection circuit can notify the first protection circuit of the detection of a second overcurrent.

[0077] In the display device 1 according to aspect 3 of the present disclosure, in aspect 2 above, it is preferable that the first protection circuits 6, 6A, 6B, 6C switch the setting values ​​in the first protection circuits 6, 6A, 6B, 6C in response to receiving the notification signal.

[0078] According to the above configuration, the setting value of the first protection circuit can be appropriately changed in response to the stop of the second gate drive circuit protected by the second protection circuit which has detected the second overcurrent.

[0079] In the display device 1 according to aspect 4 of the present disclosure, in aspect 3 above, it is preferable that the first protection circuits 6, 6A, 6B, and 6C switch the thresholds LIM1_SET and LIM2_SET for detecting the first overcurrent in response to receiving the notification signal.

[0080] According to the above configuration, the threshold value for the first protection circuit to detect the first overcurrent can be appropriately changed in response to the stop of the second gate drive circuit protected by the second protection circuit which has detected the second overcurrent.

[0081] In the display device 1 according to aspect 5 of the present disclosure, in aspect 4 above, the first protection circuits 6, 6A, 6B, 6C are configured to be able to select a plurality of thresholds including a first threshold (threshold LIM1_SET) and a second threshold (threshold LIM2_SET) higher than the first threshold as a threshold for detecting the first overcurrent, and it is preferable that the threshold for detecting the first overcurrent is switched from the first threshold (threshold LIM1_SET) to the second threshold (threshold LIM2_SET) in response to receiving the notification signal.

[0082] According to the above configuration, the threshold for detecting the first overcurrent can be switched by switching the threshold from the first threshold to the second threshold in response to reception of the notification signal.

[0083] In the display device 1 according to aspect 6 of the present disclosure, in aspect 2 above, it is preferable that the second protection circuits 7, 7A, 7B, and 7C cut off the second overcurrent in response to detection of the second overcurrent and supply the notification signal to the protection circuit connecting wiring 8.

[0084] According to the above configuration, the second protection circuit can notify the first protection circuit of the detection of the second overcurrent in response to the detection of the second overcurrent.

[0085] In the display device 1 according to aspect 7 of the present disclosure, in aspect 3 above, it is preferable that the second protection circuits 7, 7A, 7B, and 7C switch the setting values ​​in the second protection circuits 7, 7A, 7B, and 7C in response to receiving the notification signal.

[0086] According to the above configuration, the second protection circuit can switch the setting value for detecting the second overcurrent in response to receiving a notification signal notifying the detection of the first overcurrent.

[0087] In the display device 1 according to aspect 8 of the present disclosure, in aspect 7 above, it is preferable that the first protection circuits 6, 6A, 6B, and 6C switch the thresholds for detecting the first overcurrent in response to receiving the notification signal, and the second protection circuits 7, 7A, 7B, and 7C switch the thresholds LIM1_SET and LIM2_SET for detecting the second overcurrent in response to receiving the notification signal.

[0088] According to the above configuration, the threshold value of the first protection circuit for detecting the first overcurrent is switched in response to reception of a notification signal notifying the detection of a second overcurrent by the second protection circuit, and the threshold value of the second protection circuit for detecting a second overcurrent is switched in response to reception of a notification signal notifying the detection of the first overcurrent by the first protection circuit.

[0089] A display device 1 according to a ninth aspect of the present disclosure is, in the above-mentioned eighth aspect, preferably wherein the first protection circuits 6, 6A, 6B, 6C are configured to be able to select a plurality of thresholds as a threshold for detecting the first overcurrent, including a first threshold (threshold LIM1_SET) and a second threshold (threshold LIM2_SET) higher than the first threshold (threshold LIM1_SET), and switch the threshold for detecting the first overcurrent from the first threshold (threshold LIM1_SET) to the second threshold (threshold LIM2_SET) in response to receiving the notification signal; and the second protection circuits 7, 7A, 7B, 7C are configured to be able to select a plurality of thresholds as a threshold for detecting the second overcurrent, including a third threshold (threshold LIM1_SET) and a fourth threshold (threshold LIM2_SET) higher than the third threshold (threshold LIM1_SET), and switch the threshold for detecting the second overcurrent from the third threshold (threshold LIM1_SET) to the fourth threshold (threshold LIM2_SET) in response to receiving the notification signal.

[0090] According to the above configuration, the threshold for detecting the first overcurrent can be switched, and the threshold for detecting the second overcurrent can also be switched.

[0091] In the display device 1 according to aspect 10 of the present disclosure, in aspect 6 above, it is preferable that the first protection circuits 6, 6A, 6B, 6C cut off the first overcurrent in response to detection of the first overcurrent and supply the notification signal to the protection circuit connecting wiring 8.

[0092] According to the above configuration, the first protection circuit can notify the second protection circuit of the detection of the first overcurrent.

[0093] The display device 1 according to an eleventh aspect of the present disclosure, in any of the first to tenth aspects above, further comprises a control board 9 having a timing controller 10 for controlling operation timing of the first gate drive circuit 4 and the second gate drive circuit 5 provided thereon, and a third protection circuit 11 arranged on the control board 9 for detecting the first overcurrent and the second overcurrent to protect the first gate drive circuit 4 and the second gate drive circuit 5 from the first overcurrent and the second overcurrent, preferably wherein a threshold for detecting the first overcurrent in the third protection circuit 11 is higher than a threshold for detecting the first overcurrent in the first protection circuits 6, 6A, 6B, and 6C, and a threshold for detecting the second overcurrent in the third protection circuit 11 is higher than a threshold for detecting the second overcurrent in the second protection circuits 7, 7A, 7B, and 7C.

[0094] According to the above configuration, the threshold value of the first protection circuit and the threshold value of the second protection circuit are lower than the threshold value of the third protection circuit, so it is possible to avoid a situation in which the third protection circuit operates before the first protection circuit and the second protection circuit, causing the entire display on the display panel to disappear.

[0095] The display device 1 according to aspect 12 of the present disclosure, in any of aspects 1 to 10 above, further comprises a source substrate 12 connected to the display panel 2 via a flexible circuit board 13 having a source driving circuit 14 that supplies video signals to a plurality of source bus lines SL connected to the pixel array 3, and it is preferable that the first protection circuits 6, 6A, 6B, 6C and the second protection circuits 7, 7A, 7B, 7C are arranged on the source substrate 12.

[0096] According to the above configuration, since the influence of transmission loss and reflection is small on the source substrate, the thresholds of the first and second protection circuits can be set by considering only the characteristics of the gate drive circuit on the GOA panel. Therefore, it is not necessary to provide a margin for the thresholds of the first and second protection circuits considering the influence of transmission loss and reflection.

[0097] The display device 1 according to aspect 13 of the present disclosure, in any of aspects 1 to 10 above, further comprises a source substrate 12 connected to the display panel 2 via a flexible circuit board 13 having a source driving circuit 14 that supplies video signals to a plurality of source bus lines SL connected to the pixel array 3, and a control substrate 9 connected to the source substrate 12 and having a timing controller 10 that controls the operation timing of the first gate driving circuit 4, the second gate driving circuit 5, and the source driving circuit 14, and it is preferable that the first protection circuits 6, 6A, 6B, 6C and the second protection circuits 7, 7A, 7B, 7C are arranged on the control substrate 9.

[0098] According to the above configuration, the first protection circuit and the second protection circuit can be integrated into a single-chip control substrate, so that the protection circuit connection wiring that connects the first and second protection circuits can be formed short within the single chip, and the number of terminals required for the connector that connects the control substrate and the source substrate does not increase by the amount of the protection circuit connection wiring.

[0099] A display device 1 according to aspect 14 of the present disclosure, in any one of aspects 1 to 10 above, preferably includes the first protection circuits 6A·6B and / or the second protection circuits 7A·7B including transistors T1, T2, ..., Tn connected to input wiring IN1, IN2, ..., INn and output wiring OUT1, OUT2, ..., OUTn, current detection circuits K1, K2, ..., Kn connected to the transistors T1, T2, ..., Tn, a control circuit 16 controlling the transistors T1, T2, ..., Tn in accordance with outputs of the current detection circuits K1, K2, ..., Kn, and capacitors C1, C2, ..., Cn connected in parallel to the transistors T1, T2, ..., Tn.

[0100] According to the above configuration, since a capacitor is provided in parallel with the transistors connected to the input wiring and the output wiring, it is possible to prevent the peak currents at the rising and falling edges of the input signal input from the input wiring from being detected as the first overcurrent and the second overcurrent, and therefore it is possible to keep the thresholds for detecting the first overcurrent and the second overcurrent low.

[0101] In the display device 1 of aspect 15 of the present disclosure, in aspect 14 above, it is preferable that the first protection circuit 6B and / or the second protection circuit 7B further include peak current cutoff transistors PT1, PT2, ..., PTn connected in series to the capacitors C1, C2, ..., Cn.

[0102] According to the above configuration, when the first protection circuit and the second protection circuit detect the first overcurrent and the second overcurrent and cut off the input signal, they can also cut off the peak currents at the rising and falling edges of the input signal.

[0103] In the display device 1 according to aspect 16 of the present disclosure, in any one of aspects 3 to 5 above, it is preferable that the first protection circuit 6C includes a register 22 in which the setting value that is switched in response to reception of the notification signal is written.

[0104] According to the above configuration, the thresholds for detecting the first overcurrent and the second overcurrent are set by the register values, so that the thresholds can be easily changed.

[0105] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. The technical scope of the present disclosure also includes embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Furthermore, new technical features can be formed by combining the technical means disclosed in the respective embodiments. [Explanation of symbols]

[0106] 1 Display device 2 Display Panel 3. Pixel Array 4 First gate drive circuit 5 Second gate drive circuit 6 1st protection circuit 7 Second protection circuit 8 Protection circuit connection wiring 9 Control Board 10 Timing Controller 11 Third protection circuit 12 Source Board 13 Flexible Circuit Board 14 Source driver circuit 15 Power management IC 16 Control circuit 17 Current limit setting circuit 22 Registers T1, T2, …, Tn transistors IN1, IN2, …, INn input wiring OUT1, OUT2, …, OUTn output wiring C1, C2, …, Cn Capacitors PT1, PT2, ..., PTn Peak current cutoff transistors PX pixels GL Gate Bus Line SL Source bus line BK_SEL input / output terminal LIM1_SET threshold (first threshold) LIM2_SET threshold (second threshold) I3 Normal current I4 overcurrent

Claims

1. a display panel including a pixel array including a plurality of pixels, a plurality of gate bus lines connected to the pixel array, a first gate drive circuit disposed on one side of the pixel array and supplying scanning signals to the plurality of gate bus lines, and a second gate drive circuit disposed on the opposite side of the pixel array to the first gate drive circuit and supplying scanning signals to the plurality of gate bus lines; a first protection circuit that detects a first overcurrent supplied to the first gate drive circuit and protects the first gate drive circuit from the first overcurrent; a second protection circuit that is separate from the first protection circuit and detects a second overcurrent supplied to the second gate drive circuit and protects the second gate drive circuit from the second overcurrent; A display device comprising:

2. 2. The display device according to claim 1, further comprising a protection circuit connection wiring that connects the first protection circuit and the second protection circuit, and to which a notification signal that notifies of detection of the first overcurrent or the second overcurrent is supplied.

3. The display device according to claim 2 , wherein the first protection circuit switches a setting value in the first protection circuit in response to receipt of the notification signal.

4. The display device according to claim 3 , wherein the first protection circuit switches a threshold value for detecting the first overcurrent in response to receipt of the notification signal.

5. The first protection circuit includes: A plurality of thresholds including a first threshold and a second threshold higher than the first threshold can be selected as a threshold for detecting the first overcurrent, The display device according to claim 4 , wherein a threshold value for detecting the first overcurrent is switched from the first threshold value to the second threshold value in response to reception of the notification signal.

6. The display device according to claim 2 , wherein the second protection circuit cuts off the second overcurrent in response to detection of the second overcurrent and supplies the notification signal to the protection circuit connection wiring.

7. The display device according to claim 3 , wherein the second protection circuit switches a setting value in the second protection circuit in response to receipt of the notification signal.

8. the first protection circuit switches a threshold for detecting the first overcurrent in response to receipt of the notification signal; The display device according to claim 7 , wherein the second protection circuit switches a threshold value for detecting the second overcurrent in response to receipt of the notification signal.

9. The first protection circuit includes: A plurality of thresholds including a first threshold and a second threshold higher than the first threshold can be selected as a threshold for detecting the first overcurrent, switching a threshold for detecting the first overcurrent from the first threshold to the second threshold in response to receiving the notification signal; The second protection circuit includes: a plurality of thresholds including a third threshold and a fourth threshold higher than the third threshold can be selected as the threshold for detecting the second overcurrent; The display device according to claim 8 , wherein a threshold value for detecting the second overcurrent is switched from the third threshold value to the fourth threshold value in response to reception of the notification signal.

10. The display device according to claim 6 , wherein the first protection circuit cuts off the first overcurrent in response to detection of the first overcurrent and supplies the notification signal to the protection circuit connection wiring.

11. a control board provided with a timing controller that controls operation timings of the first gate drive circuit and the second gate drive circuit; a third protection circuit disposed on the control board and configured to detect the first overcurrent and the second overcurrent to protect the first gate drive circuit and the second gate drive circuit from the first overcurrent and the second overcurrent, 11. The display device of claim 1, wherein a threshold for detecting the first overcurrent in the third protection circuit is higher than a threshold for detecting the first overcurrent in the first protection circuit, and a threshold for detecting the second overcurrent in the third protection circuit is higher than a threshold for detecting the second overcurrent in the second protection circuit.

12. a source substrate connected to the display panel via a flexible circuit board provided with a source driving circuit for supplying video signals to a plurality of source bus lines connected to the pixel array; The display device according to claim 1 , wherein the first protection circuit and the second protection circuit are disposed on the source substrate.

13. a source substrate connected to the display panel via a flexible circuit board provided with a source driving circuit for supplying video signals to a plurality of source bus lines connected to the pixel array; a control substrate connected to the source substrate and provided with a timing controller for controlling operation timings of the first gate drive circuit, the second gate drive circuit, and the source drive circuit; The display device according to claim 1 , wherein the first protection circuit and the second protection circuit are disposed on the control substrate.

14. The first protection circuit and / or the second protection circuit, A transistor connected to an input wiring and an output wiring; a current sensing circuit coupled to the transistor; a control circuit for controlling the transistor in response to an output of the current detection circuit; The display device according to claim 1 , further comprising: a capacitor connected in parallel to the transistor.

15. The display device according to claim 14 , wherein the first protection circuit and / or the second protection circuit further includes a peak current cutoff transistor connected in series with the capacitor.

16. The display device according to claim 3 , wherein the first protection circuit includes a register in which the setting value that is switched in response to reception of the notification signal is written.

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