TWI754380B - Display device - Google Patents

Abstract

A display device is provided. The display device includes a controller and a plurality of first light emitting diodes. The plurality of first light emitting diodes are arranged alternately with a plurality of second light emitting diodes, and the first light emitting diodes are respectively coupled to the second light emitting diodes. Each of the second light emitting diodes receives a driving current. When each of the second light emitting diodes is disconnected, the driving current corresponding to each of the second light emitting diodes is transmitted to the corresponding each of the first light emitting diodes.

Description

display device

The present invention relates to a display device and a driving method thereof, and more particularly, to a display device and a driving method thereof having a component damage compensation function to improve reliability.

In a display device system, whether it is an active matrix (Active matrix) controller or a controlled element, such as a light emitting diode (LED), it is unavoidable that failures may occur, resulting in display device failures. A defect occurs. Therefore, how to repair and compensate these defects so as to improve the reliability of the display device and avoid a substantial increase in the cost of components has become an important issue.

The present invention provides a display device and a driving method thereof, which have a component damage compensation function and can improve the reliability of the display device.

The display device of the present invention includes a controller, a plurality of first light emitting diodes, and a plurality of second light emitting diodes. A plurality of first light emitting diodes are coupled to the first side of the controller, and are respectively arranged alternately with a plurality of second light emitting diodes, and the plurality of first light emitting diodes are respectively coupled to the plurality of second light emitting diodes Each second light emitting diode receives a driving current, and when each second light emitting diode is disconnected, the corresponding driving current of each second light emitting diode is transmitted to each corresponding first light emitting diode.

Based on the above, the display device of the present invention uses the first controller to drive the first light-emitting diode, and when the first light-emitting diode is disconnected (eg, in a damaged state), the second controller can be used to drive the first light-emitting diode. The second light-emitting diode is used to compensate the brightness of the defect caused by the damage of the first light-emitting diode, thereby achieving the purpose of compensating for element damage and improving the reliability of the display device.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, the following embodiments are given and described in detail with the accompanying drawings as follows.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. The same reference numerals refer to the same elements throughout the specification. It will be understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element, or Intermediate elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. As used herein, "connected" may refer to a physical and/or electrical connection. Furthermore, "electrically connected" or "coupled" refers to the existence of other elements between the two elements.

Please refer to FIG. 1 , which is a schematic block diagram of a circuit of a display device according to an embodiment of the present invention. The display device 100 includes light emitting diodes LED1 to LED2 and controllers 110 and 120 . The controller 110 has a current source SOU1, the current source SOU1 is coupled in series with the cathode of the light emitting diode LED1, and the anode of the light emitting diode LED1 receives the system voltage VLED. The controller 120 has a current source SOU2, one end of the current source SOU2 is coupled in series with the cathode of the light-emitting diode LED2, the other end of the current source SOU2 is coupled to the reference ground voltage GND, and the anode of the light-emitting diode LED2 is The system voltage VLED is also received, wherein the light-emitting diodes LED1 and LED2 have the same emission wavelength, and the light-emitting diodes LED1 and the light-emitting diodes LED2 are arranged alternately with each other. In addition, the current source SOU1 is also coupled to the coupling point (eg, the node CE1 ) of the current source SOU2 and the light emitting diode LED2 .

Accordingly, when the light-emitting diode LED1 is in a normal state (ie, a state where no damage has occurred), the controller 120 causes the current source SOU2 to draw the current of the current source SOU1 , so that the current source SOU1 provides the driving current Idr1 to turn on light emission Diode LED1. It should be noted that, in this embodiment, the currents of the current source SOU1 and the current source SOU2 are the same, so according to the Kirchhoffs Current Law (KCL), the current flowing into the node CE1 at this time (ie the current source The driving current Idr1 provided by SOU1 is substantially the same as the current flowing out of the node CE1 (that is, the current of the current source SOU2 ), therefore, the light-emitting diode LED2 does not have a current flowing (that is, the current value of the driving current Idr2 is, for example, zero or approaching zero), that is, when the light-emitting diode LED1 is in a normal state, the light-emitting diode LED2 serving as a backup light-emitting diode does not emit light.

On the other hand, when the light emitting diode LED1 is damaged and disconnected, the current path of the driving current Idr1 is disconnected, and the current source SOU1 stops providing the driving current Idr1. At this time, the current source SOU2 will provide the driving current Idr2 to turn on the light-emitting diode LED2, so that the light-emitting diode LED2 can compensate the light-emitting brightness that the light-emitting diode LED1 cannot provide. In this way, in the present invention, when the light-emitting diode LED1 is in an open-circuit state, the light-emitting diode LED2 with the same light-emitting wavelength can be used as a backup light-emitting diode to compensate the display device 100 due to the light-emitting diode LED1 . Defects caused by damage to achieve the purpose of improving reliability.

Incidentally, in the display device 100 of this embodiment, when the controller 110 is damaged, the controller 110 cannot provide the driving current Idr1. The controller 120 enables the current source SOU2 to provide the driving current Idr2 to drive the light-emitting diode LED2 to compensate for the defect that the light-emitting diode LED1 cannot emit light due to the damage of the controller 110 .

Please refer to FIG. 2A . FIG. 2A is a schematic diagram of a display device according to another embodiment of the present invention. The display device 200 of this embodiment includes a shift register SR, light emitting diodes R1 ˜ R2 , G1 ˜ G2 , B1 ˜ B2 , transistors T1 ˜ T6 , and a plurality of controllers (eg, the controller 210 ). It should be noted that the display device 200 of the present invention includes a plurality of controllers that are coupled to each other (for example, a structure of a coupling manner of a plurality of sets of controllers 110 and 120 as shown in FIG. 1 ), and the display device Each controller in 200 can be respectively coupled to a plurality of light-emitting diodes and a plurality of transistors. For the sake of simplicity, FIG. 2A only shows the controller 210 and the light-emitting diodes R1-R2 coupled to the controller 210. , G1-G2, B1-B2, and transistors T1-T6, as an exemplary embodiment, but the present invention does not actually limit the number of controllers, light-emitting diodes and transistors. The knowledgeable person can adjust the number of controllers, light-emitting diodes and transistors according to the actual application.

In addition, in this embodiment, the light-emitting diodes R1, G1, and B1 are used as the main light-emitting diodes of the controller 210, and the light-emitting diodes R2, G2, and B2 are used as the main light-emitting diodes in the next-level controller. the backup light-emitting diode, but the present invention is not limited to this.

It should be noted that, in this embodiment, the light-emitting diodes R1 and R2 have the same light-emitting wavelength, and may be, for example, red light-emitting diodes. The light-emitting diodes G1, G2 have the same emission wavelength and may be, for example, green light-emitting diodes. The light emitting diodes B1, B2 have the same emission wavelength and may be, for example, blue light emitting diodes. That is, the light-emitting wavelengths of the light-emitting diodes R1, R2 may be different from the light-emitting wavelengths of the light-emitting diodes G1, G2, and the light-emitting wavelengths of the light-emitting diodes R1, R2 may be different from the light-emitting wavelengths of the light-emitting diodes B1, B2 different wavelengths. It should be noted that, in other embodiments of the present invention, the light-emitting wavelengths of the light-emitting diodes R1 and R2 may also be the same as those of the light-emitting diodes G1, G2, B1, and B2, which are not limited in the present invention. Those with ordinary knowledge in the art can adjust the light-emitting wavelengths of the light-emitting diodes R1-R2, G1-G2, and B1-B2 according to the actual application.

The controller 210 includes control signal generators 211a-211b, current controllers 212a-212b, switches S1-S6, and current sources SOU21-SOU29. The controller 210 receives the scan signal Scan, the data signal Data and the clock signal CLK to determine whether to receive the data signal Data according to the scan signal Scan. Incidentally, the scan signal Scan, the data signal Data, and the clock signal CLK can be provided by, for example, a timing controller, but the invention is not limited thereto. On the other hand, the shift register SR is used for receiving the scanning signal of the previous stage, and providing the scanning signal of the subsequent stage, so that the pixels of each column of the display device 200 can be scanned in sequence. To be described in detail, the shift register SR provides a plurality of sequentially enabled control signals MR1_1 , MG1_1 , and MB1_1 to turn on the transistors T1 ˜ T3 , so that the light emitting diodes R1 , G1 , and B1 receive the system voltage VLED. In addition, the shift register at the next stage of the shift register SR will provide a plurality of control signals MR1_2, MG1_2, and MB1_2 that are enabled in sequence to turn on the transistors T4-T6, so that the light-emitting diodes R2 and G2 are turned on. , B2 receives the system voltage VLED, and so on.

In addition, in the controller 210, the switch S1 is coupled between the light-emitting diode R1 and the current source SOU21, and is turned on or off according to the control signal SR1. The switch S2 is coupled between the light emitting diode G1 and the current source SOU22, and is turned on or off according to the control signal SG1. The switch S3 is coupled between the light emitting diode B1 and the current source SOU23, and is turned on or off according to the control signal SB1. The switch S4 is coupled between the light emitting diode R2 and the current source SOU24, and is turned on or off according to the control signal SR2. The switch S5 is coupled between the light emitting diode G2 and the current source SOU25, and is turned on or off according to the control signal SG2. The switch S6 is coupled between the light emitting diode B2 and the current source SOU26, and is turned on or off according to the control signal SB2. It should be noted that the transistors T1 to T6 in this embodiment may be implemented by, for example, P-type transistors or N-type transistors. The present invention is implemented by using P-type transistors as an exemplary embodiment. Inventions are not limited to this. In addition, the switches S1 to S6 in this embodiment can also be implemented by, for example, a P-type transistor or an N-type transistor, which is not limited in the present invention.

On the other hand, in this embodiment, the control signal generator 211a is used for providing the control signals SR1, SG1, SB1 to control the switches S1-S3 respectively. The control signal generator 211b is used for providing control signals SR2, SG2, SB2 to control the switches S4-S6 respectively. Incidentally, the control signals SR1 ˜SR2 , SG1 ˜ SG2 , and SB1 ˜SB2 in this embodiment may be, for example, pulse width modulation (PWM) signals, but the present invention is not limited thereto. The current controller 212a is used for providing the current control signals IR1_1, IG1_1, and IB1_1 to control the currents of the current sources SOU21-SOU23 respectively (for example, controlling the proportional value of the output current values of the current sources SOU21-SOU23). The current controller 212b is used for providing the current control signals IR1_2, IG1_2, and IB1_2 to control the currents of the current sources SOU24-SOU26 respectively (for example, controlling the proportional value of the output current values of the current sources SOU24-SOU26). Incidentally, the current sources SOU27 to SOU29 are current sources in the next-stage controller of the controller 210 . It should be noted that the element coupling method between the controller 210 and the next-stage controller in this embodiment and the The compensation method for component damage is similar to that of the aforementioned embodiment in FIG. 1 , and details are not repeated here.

Next, please refer to FIG. 2A and FIG. 2B synchronously. FIG. 2B is a schematic diagram of signal waveforms of the display device according to the embodiment of FIG. 2A of the present invention. During the time interval TA, the display device 200 performs a data access operation, the scan signal Scan changes from the disable voltage level to the enable voltage level, and the controller 210 receives the time when the switching frequency is the clock signal Clk_data The pulse signal CLK is used, and the data access operation is performed on the data signal Data according to the clock signal CLK. It should be noted that the switching frequency of the clock signal Clk_data is higher than the switching frequency of the clock signal Clk_PWM, and the clock signal Clk_data and the clock signal Clk_PWM can also be sent by a timing controller, for example. In this way, the display device 200 of this embodiment can perform data access operations by switching the clock signal Clk_data with a higher frequency, thereby accelerating data collection and access. On the other hand, in the time interval TA, the control signals SR1, SG1, SB1, and the control signals MR1_1, MG1_1, and MB1_1 are all disabled voltage levels (and also the transistors T1~T3 and the switches S1~S3 are turned off at this time. ). In addition, in this embodiment, the voltage levels of the control signals SR2, SG2, SB2, and the control signals MR1_2, MG1_2, and MB1_2 are related to the switches and transistors of the main light-emitting diodes in the next-stage controller. control signals are the same.

In the time interval TB after the time interval TA, the display device 200 will perform a driving display operation, and the scan signal Scan will change from the enable voltage level to the disable voltage level. At this time, the controller 210 receives the switching frequency as The clock signal CLK of the clock signal Clk_PWM provides the control signals SR1, SG1, and SB1 whose states are turned to enable voltage levels to turn on the switches S1-S3, and provides the enable control signals MR1_1, MG1_1, and MB1_1 in sequence to turn on the transistors T1~T3, so that the multiple current sources in the controller of the upper stage draw current from the current sources SOU21, SOU22, SOU23 respectively to generate the driving currents IR1_out, IG1_out, IB1_out to drive the light-emitting diodes R1, G1, B1 .

Incidentally, when the main light-emitting diode in the next-level controller is damaged and the circuit is broken (or the next-level controller is damaged), the current sources SOU27, SOU28, SOU29 in the next-level controller stop providing driving current ( For example, driving currents IR2_in, IG2_in, IB2_in), the controller 210 makes the current sources SOU24, SOU25, and SOU26 respectively provide driving currents with the same current size as the current sources SOU27, SOU28, and SOU29 to drive the light-emitting diodes R2, G2, B2. Incidentally, the light-emitting diodes R1, G1, and B1 in the display device 200 are arranged in a staggered manner with the backup light-emitting diodes in the upper-level controller, and the light-emitting diodes R2, G2, and B2 are arranged with the lower-level controller. The main LEDs in the controller are staggered.

In addition, as mentioned in other embodiments of the present invention, the switches S1-S6 can be used to replace the functions of the transistors T1-T6, that is, when the display device 200 of the present embodiment performs the display driving operation, the controller 210 will Provide sequentially enabled control signals SR1, SG1, SB1 to turn on the switches S1-S3, so that the current sources SOU21, SOU22, SOU23 can respectively provide driving currents IR1_out, IG1_out, IB1_out to drive the light-emitting diodes R1, G1, B1.

Please refer to FIG. 3 , which is a schematic block diagram of a circuit of a display device according to another embodiment of the present invention. The display device 300 of this embodiment includes a controller 310 , a plurality of first light-emitting diodes (eg, light-emitting diodes r31 , g31 , b31 ) and a plurality of second light-emitting diodes (eg, light-emitting diodes R32 ) , G32, B32). A plurality of first light-emitting diodes (ie, light-emitting diodes r31 , g31 , b31 ) are coupled to the first side of the controller 310 (eg, the lower side of the controller 310 in FIG. 3 ). The light emitting diodes r31 , g31 and b31 are arranged alternately with the light emitting diodes R32 , G32 and B32 respectively, and the light emitting diodes r31 , g31 and b31 are respectively coupled to the light emitting diodes R32 , G32 and B32 . It is worth mentioning that each light-emitting diode R32, G32, B32 will receive the driving current. When each light-emitting diode R32, G32, B32 is disconnected, the driving current corresponding to each light-emitting diode R32, G32, B32 will be transmitted to the corresponding light-emitting diodes r31, g31, b31. It should be noted that, in this embodiment, the light-emitting diodes R32, G32, and B32 are used as the main light-emitting diodes of the next-level controller of the controller 310, while the light-emitting diodes r31, g31, b31 is used as a backup light-emitting diode for the main light-emitting diodes (ie, the light-emitting diodes R32, G32, B32) in the next-level controller, but the present invention is not limited to this.

In addition, as mentioned in other embodiments of the present invention, the display device 300 further includes a plurality of third light-emitting diodes (eg, light-emitting diodes R31, G31, B31), light-emitting diodes R31, G31, B31 is coupled to the second side of the controller 310 (eg, the upper side of the controller 310 in FIG. 3 ), wherein the first side (ie the lower side) is opposite to the second side (ie the upper side), And the light-emitting diodes R31, G31, B31 and the light-emitting diodes r31, g31, b31 are arranged alternately. In other words, the controller 310 of this embodiment may also include main light-emitting diodes (ie, the light-emitting diodes R31, G31, B31), and the light-emitting diodes R31, G31, B31 will be connected with the light-emitting diodes r31, g31 and b31 present an asymmetric configuration.

It is not difficult to know from the above description that the display device 300 of the present invention can control the main light-emitting diodes (ie the light-emitting diodes R31, G31, B31) and the backup light-emitting diodes simultaneously by one controller (eg, the controller 310). Polar body (ie light-emitting diodes r31, g31, b31). In this way, the present invention can reduce the additional setting of a controller only for controlling the backup light-emitting diode, thereby increasing the use efficiency of the controller and reducing the cost of components.

It should be noted that, the driving manner of the light-emitting diodes in the controller 310 of this embodiment is similar to that of the aforementioned embodiment of FIG. 2A , and details are not repeated here. In addition, the element coupling method and the element damage compensation method between the controller 310 of the present embodiment and the controller of the next stage are similar to those of the aforementioned embodiment in FIG. 1 , and details are not repeated here.

Next, please refer to FIG. 3 and FIG. 4 synchronously. FIG. 4 is a schematic block diagram of a circuit of a display device according to another embodiment of the present invention. The display device 400 of this embodiment includes a plurality of controllers (eg, controllers 410 to 450 ), a timing controller Tcon, and a plurality of light-emitting diodes (ie, light-emitting diodes R42 to R43 , G42 ) corresponding to each controller ~G43, B42~B43, r41~r42, g41~g42, b41~b42, R51, G51, B51, r44, g44, b44). The timing controller Tcon is coupled to the controllers 410-450, and the timing controller Tcon is used to provide the scan signal, the data signal and the clock signal to the controllers 410-450 as described in the embodiment of FIG. 2A, which will not be repeated here. . It should be noted that, in order to simplify the description, only five controllers and corresponding light-emitting diodes are shown in FIG. To be limited, the illustration in FIG. 4 is not intended to limit the present invention.

It is worth mentioning that, in this embodiment, the controllers 410 to 450 may be constituted by, for example, a plurality of the controllers 310 in FIG. The controller 410) only includes the backup LEDs (ie, the LEDs r41, g41, b41), and the controller (eg, the controller 450) located at the lowermost side of the display device 400 in FIG. 4 only includes the main Light-emitting diodes (ie, light-emitting diodes R51, G51, B51). It should be noted that the element coupling method and the element damage compensation method between the controllers 410 to 450 are similar to the aforementioned embodiment in FIG.

It is not difficult to know from the above description that in the display device 400 of the present embodiment, when at least one of the main light-emitting diodes of the controller is disconnected, the backup of the same light-emitting wavelength of the adjacent controller can be used. Light-emitting diodes are used to compensate. For example, when the main light-emitting diodes R42, G42, B42 of the controller 420 are disconnected, the light-emitting diodes of the same light-emitting wavelength in the adjacent controller 410 can be driven by driving the light-emitting diodes G42, B42 body g41, b41 to compensate. When the controller 430 is damaged, the light-emitting diodes R43, G43, and B43 may not be able to emit light due to the damage of the controller 430. At this time, the light-emitting diodes with the same light-emitting wavelength in the adjacent controllers 420 can be driven. r42, g42, b42 to compensate, and so on.

Please refer to FIG. 5 , which is a flowchart illustrating a method for operating a display device according to an embodiment of the present invention. First, in step S510, a first current source is provided, the first current source is coupled in series with the first light emitting diode, and the first current source is coupled to the first node. In step S520, a second current source is provided, the second current source is coupled in series with the second light emitting diode, and the second current source is coupled to the first node. Next, in step S530, when the first light-emitting diode is normal, the first current source is made to provide a first driving current to drive the first light-emitting diode. In step S540, when the first light-emitting diode is disconnected, the first current source stops providing the first driving current, and the second current source provides the second driving current to drive the second light-emitting diode.

It should be noted that, the implementation details of steps S510 to S540 have been described in detail in the foregoing embodiments and implementation manners, and will not be repeated here.

To sum up, the display device of the present invention uses the first controller to drive the first light-emitting diode, and when the first light-emitting diode is damaged and the circuit is broken (or the first controller is damaged), the second controller is used to drive the first light-emitting diode. To drive the second light-emitting diode, to use the second light-emitting diode to compensate for the defects caused by the damage of the first light-emitting diode, so as to achieve the purpose of component damage compensation and effectively improve the Display device reliability.

Although the present invention has been disclosed above by the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention shall be determined by the scope of the appended patent application.

100, 200, 300, 400: Display device 110, 120, 210, 310, 410~450: Controller 211a, 211b: control signal generator 212a, 212b: Current controller CE1: Node CLK, Clk_PWM, Clk_data: clock signal Data: data signal GND: Reference ground voltage Idr1, Idr2, IR1_out, IG1_out, IB1_out, IR2_in, IG2_in, IB2_in: drive current IR1_1, IG1_1, IB1_1, IR1_2, IG1_2, IB1_2: Current control signal LED1, LED2, R1~R2, G1~G2, B1~B2, R31~R32, r31, G31~G32, g31, B31~B32, b31, r41~r42, g41~g42, b41~b42, R42~R43, G42~G43, B42~B43, r44, g44, b44, R51, G51, B51: LEDs MR1_1, MG1_1, MB1_1, MR1_2, MG1_2, MB1_2: Control signals S1~S6: switch S510~S530: the step flow of the display device driving method Scan: scan signal SOU1, SOU2, SOU21~ SOU 29: Current source SR: shift register SR1, SG1, SB1, SR2, SG2, SB2: Control signal T1~T6: Transistor TA, TB: time interval Tcon: Timing Controller VLED: system voltage

FIG. 1 is a schematic block diagram of a circuit of a display device according to an embodiment of the present invention. FIG. 2A is a schematic circuit block diagram of a display device according to another embodiment of the present invention. FIG. 2B is a schematic diagram of signal waveforms of the display device according to the embodiment of FIG. 2A of the present invention. FIG. 3 is a schematic block diagram of a circuit of a display device according to another embodiment of the present invention. FIG. 4 is a schematic circuit block diagram of a display device according to another embodiment of the present invention. FIG. 5 is a flowchart illustrating a method for driving a display device according to an embodiment of the present invention.

300: Display device

310: Controller

R31, R32, G31, G32, B31, B32, r31, g31, b31: LEDs

Claims (8)

A display device, comprising: a controller; and a plurality of first light emitting diodes, coupled to a first side of the controller, and are respectively staggered with a plurality of second light emitting diodes, the first light emitting diodes The light-emitting diodes are respectively coupled to the second light-emitting diodes through the controller, wherein when each of the second light-emitting diodes is in a normal state, a driving current is provided to each of the second light-emitting diodes and the controller synchronously draws the driving current, when each of the second light-emitting diodes is disconnected, the driving current corresponding to each of the second light-emitting diodes is transmitted to the corresponding each of the second light-emitting diodes through the controller the first light emitting diode. The display device of claim 1, wherein the first controller further comprises: a first switch coupled to the first light emitting diodes; a first control signal generator for providing a first a control signal to control the first switch to be turned on or off; and a first current controller to provide a first current control signal to control the current size of the driving current. The display device of claim 2, wherein when each of the second light-emitting diodes is disconnected, the first switch is turned on according to the first control signal, and the driving current corresponding to each of the second light-emitting diodes is sent to the corresponding first light emitting diodes. The display device of claim 1, further comprising: a plurality of third light emitting diodes coupled to a second side of the controller, wherein the first side is opposite to the second side. The display device of claim 4, wherein the third light emitting diodes and the first light emitting diodes are arranged in a staggered manner. The display device of claim 4, wherein the first controller further comprises: a second switch coupled to the third light emitting diodes; and a second control signal generator for providing a first Two control signals to control the second switch to be turned on or off. The display device of claim 6, wherein when the third light-emitting diodes are normal, the second switch is turned on according to the second control signal, so that the controller drives the third light-emitting diodes . The display device of claim 1, wherein the first light emitting diodes and the second light emitting diodes are arranged in a staggered manner.

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