TWI614741B - External compensation method and driver ic using the same - Google Patents

External compensation method and driver ic using the same Download PDF

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Publication number
TWI614741B
TWI614741B TW105136342A TW105136342A TWI614741B TW I614741 B TWI614741 B TW I614741B TW 105136342 A TW105136342 A TW 105136342A TW 105136342 A TW105136342 A TW 105136342A TW I614741 B TWI614741 B TW I614741B
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Taiwan
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sub
wire
pixels
wires
pixel
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TW105136342A
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Chinese (zh)
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TW201743312A (en
Inventor
張華罡
劉上逸
林俊傑
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聯詠科技股份有限公司
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Priority to US201662345848P priority Critical
Priority to US62/345,848 priority
Priority to US15/187,809 priority patent/US10482820B2/en
Priority to US15/187,809 priority
Priority to US15/238,728 priority
Priority to US15/238,728 priority patent/US10388207B2/en
Application filed by 聯詠科技股份有限公司 filed Critical 聯詠科技股份有限公司
Publication of TW201743312A publication Critical patent/TW201743312A/en
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Abstract

An external compensation method for an element on a board, the panel comprising a plurality of sub-pixels, the external compensation method comprising: first, one of the plurality of sub-pixels through a first wire in a first period a first component of the subpixel is programmed to sense the first component through a second wire; and in the second period, the second plurality of subpixels are second through the second wire A second component of the subpixel is programmed and senses the second component through the first wire or a third wire.

Description

External compensation method and its driving integrated circuit

The present invention relates to an external compensation method and a driver integrated circuit (Driver IC) thereof, and more particularly to an external compensation method for a panel and a drive integrated circuit for performing an external compensation method on the panel.

An Organic Light-Emitting Diode (OLED) is a type of Light-Emitting Diode (LED). The electroluminescent layer is composed of an organic compound that can receive current. And glow. Organic light-emitting diodes are widely used in display devices of electronic devices, such as television screens, computer monitors, various portable devices such as mobile phones, handheld game consoles, and personal digital assistants (PDAs). Among them, active matrix OLED (AMOLED) is the mainstream of the current organic light emitting diode display, and the active matrix organic light emitting diode can be performed by a thin film transistor (TFT). Driven, and contains storage capacitors to maintain the state of the pixels for large and high resolution displays.

In a general organic light emitting diode display, each pixel unit includes three sub-pixels, wherein each sub-pixel includes an organic light-emitting diode that can generate one of the three primary colors, and is configured to be displayed in the pixel. The color on the pixel unit. The sub-pixel can receive a voltage signal from a driver integrated circuit (Driver IC). Then, the thin film transistor converts the voltage signal into a driving current to drive the organic light emitting diode to emit light. The brightness of the organic light-emitting diode is determined by the driving current through which it passes. However, in an organic light-emitting diode display, a thin film transistor in different sub-pixels may have a component parameter error or mismatch, resulting in a difference in voltage/current conversion efficiency, and in addition, the luminous efficiency of the organic light-emitting diode. There may also be errors. When the organic light emitting diode display has been operated for a long period of time, it may face voltage/current conversion and attenuation of luminous efficiency. In this case, there may be different degrees of attenuation at various positions on the organic light emitting diode display, so that the picture consistency of the organic light emitting diode display is lowered.

In order to improve the picture consistency of the organic light emitting diode display, an effective compensation method for the parameters of the organic light emitting diode and the thin film transistor is necessary. External compensation is a common compensation method for organic light-emitting diode displays. Please refer to FIG. 1 , which is a schematic diagram of a panel 100 for performing a common external compensation method. The panel 100 includes a plurality of sub-pixels, which are arranged in a matrix form. For each row of sub-pixels, a source line connects the sub-pixels to a driver integrated circuit (not shown), so that the display data can be output to the thin film transistor in the sub-pixel through the data line. . At the same time, a sensing line is also coupled between each row of sub-pixels and the driving integrated circuit. The sensing line can be used for external compensation, which can transmit the electrical characteristics of the thin film transistor or the organic light emitting diode in the subpixel to the driving integrated circuit, so that the driving integrated circuit can perform subsequent processing according to the received electrical characteristic data. . In this case, each row of pixels requires two wires for communicating with the driving integrated circuit, so that the driving integrated circuit has a large number of input and output pins, thereby increasing the cost of driving the integrated circuit. If the panel 100 contains N rows of sub-pixels, 2N wires are required for data display and external compensation operations. For example, a full-HD high-definition organic light-emitting diode display includes 1080 lines of pixels, that is, 1080×3 rows of sub-pixels. Therefore, the driver integrated circuit needs to include 1080×6 wires for connecting wires. Input and output pins (1080 × 3 for data lines and 1080 × 3 for sensing lines), such a large number of pins will increase the cost of driving the integrated circuit. In view of this, the prior art has been improved.

Accordingly, it is a primary object of the present invention to provide an external compensation method for a panel and a Driver Integrated Circuit (Driver IC) that can perform an external compensation method on the panel to solve the above problems.

The present invention discloses an external compensation method for an element on a board, the panel comprising a plurality of sub-pixels, the external compensation method comprising, through a first wire, a plurality of sub-pixels in a first period a first component of a first sub-pixel is programmed and sensed by a second wire; and in a second period, the plurality of sub-pixels are transmitted through the second wire A second component of a second sub-pixel is programmed and sensed by the first wire or a third wire.

The invention further discloses a driving integrated circuit for a panel for performing external compensation on the panel, the driving integrated circuit comprising a plurality of wires and a first digital to analog converter (DAC) And a first output buffer, a second digital analog converter and a second output buffer, a multiplexer and an analog to digital converter (ADC). The first digital analog converter and the first output buffer are coupled to a first one of the plurality of wires. The second digital analog converter and the second output buffer are coupled to a second one of the plurality of wires. The analog to digital converter is coupled to the first wire and the second wire through the multiplexer.

As described above, if the panel contains N rows of sub-pixels, 2N wires are required for data display and external compensation operations. In order to reduce the number of wires on the panel and the corresponding number of pins in the driver integrated circuit (Driver IC), the sub-pixels located in different rows can share the source line and the sensing line. . For example, the data line for one sub-pixel can be a sensing line for another sub-pixel.

Please refer to FIG. 2 , which is a schematic diagram of an Organic Light-Emitting Diode (OLED) display system 20 according to an embodiment of the present invention. As shown in FIG. 2, the organic light emitting diode display system 20 includes a panel 200 and a driving integrated circuit 210. The panel 200 includes a plurality of sub-pixels, which are arranged in a matrix form. The panel 200 can be coupled to the driving integrated circuit 210 through a plurality of wires. For convenience of description, only four sub-pixels P1 to P4 and five wires L1 to L5 are shown in FIG. 2, but those skilled in the art should understand that panel 200 may contain hundreds or thousands of rows of sub-pixels and wire.

As shown in FIG. 2, each sub-pixel has two contact points for connecting to the driving integrated circuit 210 through two wires. For example, the sub-pixel P1 is connected to the driving integrated circuit 210 through the wires L1 and L2, and the sub-pixel P2 is connected to the driving integrated circuit 210 through the wires L2 and L3, and so on. In this way, each wire can be shared by two adjacent sub-pixels. For example, the wire L2 can be shared by the sub-pixels P1 and P2, the wire L3 can be shared by the sub-pixels P2 and P3, and so on. Due to the sharing of the wires, the number of wires required for the panel 200 can be greatly reduced compared to the number of wires of the panel 100 in FIG. In this example, if the panel 200 contains N rows of sub-pixels, only N+1 wires are needed to realize data display and external compensation operation in the organic light-emitting diode display system 20, and at the same time, drive the integrated circuit. The number of pins on the 210 can also be greatly reduced.

In a display mode, the panel 200 can display an image according to the data from the driving integrated circuit 210, and the data can be transmitted to each row of sub-pixels through each row of wires for display. For example, subpixel P1 can receive data from wire L1, subpixel P2 can receive data from wire L2, and so on. In a compensation mode, the driver integrated circuit 210 can perform external compensation on the components on the panel 200. At this time, the driving integrated circuit 210 can program the components in a sub-pixel through a wire and pass through another pair of wires. This component is sensed. For example, the driving integrated circuit 210 can program the component in the sub-pixel P1 through the wire L1, and sense the component in the sub-pixel P1 through the wire L2; the driving integrated circuit 210 can transmit the wire L2. The component in subpixel P2 is programmed and sensed in subpixel P2 via conductor L3.

More specifically, as shown in FIG. 2, for the sub-pixel P1, an arrow starting from the wire L1 and facing a contact point of the sub-pixel P1 indicates that the wire L1 can be used as a data line for a specific The voltage signal is used to program the component in the sub-pixel P1; the arrow starting from the other contact point of the sub-pixel P1 and facing the wire L2 indicates that the wire L2 can be used as a sensing line for receiving the component in the sub-pixel P1. Electrical characteristics. For the sub-pixel P2, the arrow starting from the wire L2 and facing the contact point of one of the sub-pixels P2 indicates that the wire L2 can be used as a data line for programming the components in the sub-pixel P2 with a specific voltage signal. The arrow starting from the other contact point of the sub-pixel P2 and facing the wire L3 indicates that the wire L3 can serve as a sensing line for receiving the electrical characteristics of the element in the sub-pixel P2. And so on, according to the direction of the arrow shown in FIG. 2, those skilled in the art should be able to understand the programming and sensing operation mode of each sub-pixel on the panel 200.

In this example, each of the wires except the first row and the last row of wires can be alternately used as the data line and the sensing line. Therefore, the programming and sensing operations of the entire panel 200 can be completed in two stages. In the first period, the driving integrated circuit 210 can program the elements in the sub-pixel P1 through the wire L1 and sense the elements in the sub-pixel P1 through the wire L2. Therefore, for the sub-pixel P1, the programming operation of the wire L1 and the sensing operation of the wire L2 can be performed at the same time. Similarly, the driving integrated circuit 210 can program the components in the sub-pixel P3 through the wire L3 during the first period while sensing the components in the sub-pixel P3 through the wire L4. In the second period, the driving integrated circuit 210 can program the elements in the sub-pixel P2 through the wire L2 and sense the elements in the sub-pixel P2 through the wire L3. Therefore, for the sub-pixel P2, the programming operation of the wire L2 and the sensing operation of the wire L3 can be performed at the same time. Similarly, the driving integrated circuit 210 can program the components in the sub-pixel P4 through the wire L4 during the second period while sensing the components in the sub-pixel P4 through the wire L5. As shown in FIG. 2, the solid arrows represent programming or sensing operations performed during the first period, and the dashed arrows represent programming or sensing operations performed during the second period.

In this case, the sub-pixels on the panel 200 can be divided into two sets of sub-pixels. The components located in the first set of sub-pixels are programmed and sensed during the first period, and the components located in the second set of sub-pixels are programmed and sensed during the second period. In this example, the first group of sub-pixels includes sub-pixels located in odd-numbered lines, that is, sub-pixels P1, P3, ..., etc., and the second group of sub-pixels includes sub-pixels located in even lines. That is, sub-pixels P2, P4, ..., etc.

It should be noted that the above-described configuration for programming and sensing operations is only one of many embodiments of the present invention. For example, in another embodiment, sub-pixels located in even rows can be programmed and sensed during the first period, while sub-pixels located in odd rows are programmed and sensed during the second period. In order to further reduce the number of pins of the driving integrated circuit, a multiplexer may be disposed between the input and output pins of the driving integrated circuit and the two wires corresponding to the two rows of sub-pixels. In this case, the input and output pins of the driving integrated circuit can be selectively communicated with the two wires through the multiplexer, and the programming and sensing operations of the entire panel need more time to complete, such as four segments. period. In this way, the number of pins for driving the integrated circuit can be further reduced by half, so that the external compensation method implemented by the wire by the present invention can be applied to a small-sized display system, such as a touch screen of a smart phone.

It should also be noted that the lengths of the first period and the second period can be arbitrarily set. In other words, each programming and sensing operation can be performed within any length of time. The length of time for performing programming and sensing can be preset according to system requirements, which can be the same or different from the period during which a pixel data is displayed.

Please refer to FIG. 3, which is a schematic diagram of another organic light emitting diode display system 30 according to an embodiment of the present invention. As shown in FIG. 3, the organic light emitting diode display system 30 includes a panel 300 and a driving integrated circuit 310. The panel 300 includes a plurality of sub-pixels, which are arranged in a matrix form. The panel 300 can be coupled to the driving integrated circuit 310 through a plurality of wires. For convenience of explanation, only four sub-pixels P1' to P4' and four wires L1' to L4' are shown in FIG. 3, but those skilled in the art should understand that the panel 300 may contain hundreds or thousands of lines. Subpixels and wires. The sub-pixel configuration on the panel 300 is similar to the configuration of the panel 200, but the manner in which the two wires are shared is not the same.

In the compensation mode, the driver integrated circuit 310 can program the elements in the sub-pixel P1' through the wire L1' and sense the element in the sub-pixel P1' through the wire L2'. In another period, the driving integrated circuit 310 can program the elements in the sub-pixel P2' through the wire L2' and sense the element in the sub-pixel P2' through the wire L1'. In this way, two identical sub-pixels can share two identical wires. Due to the sharing of the wires, the number of wires required for the panel 300 can be greatly reduced compared to the number of wires of the panel 100 in FIG. In this example, if the panel 300 includes N rows of sub-pixels and N is even, only N wires are needed to realize data display and external compensation operation in the organic light-emitting diode display system 30, and at the same time, the driving product. The number of pins of the body circuit 310 can also be greatly reduced.

More specifically, as shown in FIG. 3, for the sub-pixel P1', an arrow starting from the wire L1' and facing a contact point of the sub-pixel P1' indicates that the wire L1' can be used as a data line. To program the component in the sub-pixel P1' with a specific voltage signal; the arrow starting from the other contact point of the sub-pixel P1' and facing the wire L2' indicates that the wire L2' can be used as a sensing line for receiving the sub-pixel The electrical characteristics of the component in pixel P1'. For the sub-pixel P2', the arrow starting from the wire L2' and facing the contact point of one of the sub-pixels P2' indicates that the wire L2' can be used as a data line for the sub-pixel P2' with a specific voltage signal. The component in the programming is programmed; the arrow starting from the other contact point of the sub-pixel P2' and facing the wire L1' indicates that the wire L1' can serve as a sensing line for receiving the electrical characteristics of the component in the sub-pixel P2'. And so on, according to the direction of the arrow shown in FIG. 3, those skilled in the art should be able to understand the programming and sensing operation mode of each sub-pixel on the panel 300.

Similarly, each wire can be alternately used as a data line and a sensing line, and the programming and sensing operations of the entire panel 300 can be completed in two stages. As shown in FIG. 3, the solid arrows represent programming or sensing operations performed during the first period, while the dashed arrows represent programming or sensing operations performed during the second period. Those skilled in the art can understand the detailed programming and sensing operation modes of the panel 300 according to the above paragraphs and the description of FIG. 3, and details are not described herein.

To implement the above programming and sensing methods, the driving integrated circuit of the present invention (e.g., driving integrated circuit 210 or 310) can be implemented in the following manner. Please refer to FIG. 4 , which is a schematic diagram of a circuit structure of an organic light emitting diode display system 40 and a driving integrated circuit thereof according to an embodiment of the present invention. The OLED display system 40 includes a panel 400 and a driving integrated circuit 410. The detailed circuit structure of the driving integrated circuit 410 is shown in FIG. As shown in FIG. 4, the driving integrated circuit 410 includes a plurality of wires coupled to the corresponding wires and sub-pixels on the panel. The driving integrated circuit 410 further includes a plurality of digital to analog converters (DACs) and an output buffer for programming components in the sub-pixels on the panel, and includes a plurality of analog digital converters (Analog) To Digital Converter, ADC) and multiplexer for sensing components in sub-pixels on the panel. These circuit components are all coupled to the wires through the switch. For convenience of explanation, only four wires DL1 to DL4 and their corresponding four digital analog converters DAC1 to DAC4, four output buffers B1 to B4, and two analog digital converters ADC1 to ADC2 are shown in FIG. Two multiplexers MUX1 to MUX2 and eight switches SW1 to SW8, but those skilled in the art should understand that the driving integrated circuit 410 may contain hundreds or thousands of wires and their corresponding circuit components.

In detail, in order to describe the circuit configuration of the driving integrated circuit 410, the following description will be made by taking the wires DL1 to DL2 and their corresponding circuit elements as an example. The digital analog converter DAC1 and the output buffer B1 are coupled to the wire DL1. The digital analog converter DAC2 and the output buffer B2 are coupled to the wire DL2. The analog digital converter ADC1 is coupled to the wires DL1 and DL2 through the multiplexer MUX1. In addition, the switch SW1 is coupled between the wire DL1 and the output buffer B1, the switch SW2 is coupled between the wire DL1 and the multiplexer MUX1, and the switch SW3 is coupled between the wire DL2 and the multiplexer MUX1. The switch SW4 is coupled between the wire DL2 and the output buffer B2.

In the display mode, the drive integrated circuit 410 can transmit display data to the panel 400 for image display. Therefore, the switches SW1 and SW4 are turned on, and the display data transmitted through the digital analog converters DAC1 to DAC2 and the output buffers B1 to B2 are passed, and at this time, the switches SW2 and SW3 are turned off.

In the compensation mode, the drive integrated circuit 410 performs external compensation on the panel 400. At this time, the digital analog converters DAC1 to DAC2 and the output buffers B1 to B2 can output voltage signals to program the components on the panel 400. The analog digital converter ADC1 can sense the component to receive electrical characteristics of the component from panel 400. The switches SW1 to SW4 and the multiplexer MUX1 control the drive integrated circuit 410 to selectively perform programming or sensing of components on the panel 400. Assuming that the wire arrangement of the panel 400 is similar to the configuration of the panel 300, during the first period, the switches SW1 SW SW4 and the multiplexer MUX 1 can control the driving integrated circuit 410 to pass through the wire DL1 (such as the wire L1 shown in FIG. 3). ') programming one of the first elements of the first sub-pixel on the panel 400 (such as the element in the sub-pixel P1' on the panel 300 shown in FIG. 3) and passing through the wire DL2 (as shown in FIG. 3) The wire L2') is shown to sense the first component. Then, in the second period, the switches SW1 SW SW4 and the multiplexer MUX1 can control the driving integrated circuit 410 to pass through the wire DL2 (such as the wire L2 shown in FIG. 3) to a second sub-pixel on the panel 400. A second component (such as the component in the sub-pixel P2' on the panel 300 shown in FIG. 3) is programmed and is passed through the wire DL1 (such as the wire L1' shown in FIG. 3). Sensing. It should be noted that the arrangement of the circuit elements in FIG. 4 can also be applied to the component and sub-pixel configuration on the panel 200 of FIG. 2, and the programming and sensing operations are performed in a similar manner. In this case, the second component can be programmed through the wire DL2 and sensed through the wire DL3 (such as the wire L3 shown in FIG. 2).

Fig. 5 is a view showing waveforms of the switches SW1 to SW4 of Fig. 4. It is assumed that the control signal is turned on when the control signal is at a higher level and the switch is turned off when it is at a lower level. During the first period, the switches SW1 and SW3 are turned on and the switches SW2 and SW4 are turned off. Therefore, the wire DL1 coupled to the output buffer B1 can be used as a data line, so that the digital analog converter DAC1 and the output buffer B1 can program the components in the sub-pixel on the panel 400; the wires coupled to the multiplexer MUX1 The DL2 acts as a sense line, allowing the analog to digital converter ADC1 to receive the electrical characteristics of the component. During the second period, the switches SW2 and SW4 are turned on and the switches SW1 and SW3 are turned off. Therefore, the wire DL1 coupled to the multiplexer MUX1 can serve as a sensing line, so that the analog digital converter ADC1 receives the electrical characteristics of the components in the sub-pixel on the panel 400; the wire DL2 coupled to the output buffer B2 can be used as the data. The line is programmed by the digital analog converter DAC2 and the output buffer B2.

It should be noted that the operation modes of the switches SW1 SW SW4 can be analogized to the switches SW5 SW SW 8 and the other switches in the driving integrated circuit 410 . In this case, the wires in the drive integrated circuit 410 can be divided into two sets of wires, each of the first set of wires being adjacent to one of the second set of wires. During the first period, the first set of wires (ie, the wires in the odd rows, such as DL1 and DL3) can be used as data lines for the components in the first set of subpixels (subpixels in odd rows). Programming, a second set of wires (ie, wires in even rows, such as DL2 and DL4) can be used as sense lines to sense components in the first set of subpixels. During the second period, the first set of wires can be used as a sensing line for sensing components in the second set of sub-pixels (sub-pixels in even rows), and the second set of wires can be used as data lines. To program the components in the second set of subpixels. In this way, the programming and sensing operations of the entire panel can be completed in two periods.

In addition, in the present invention, the driving integrated circuit can process the digital data and convert it into analog data through the digital analog converter, and then output the sensing data from the panel through the analog digital conversion. After the converter is converted, it can be received by the driver integrated circuit. Therefore, the digital analog converter and the analog digital converter are all necessary components for driving the integrated circuit. However, the circuit structure of the drive integrated circuit 410 in Fig. 4 is only one of many embodiments of the present invention. For example, in another embodiment, the output buffer can be integrated into a corresponding digital analog converter. In yet another embodiment, the switches SW2 and SW3 can be integrated into the multiplexer MUX1, and the switches SW6 and SW7 can be integrated into the multiplexer MUX2. Further, the switch can be implemented by any means, such as a single transistor or a transmission gate, but is not limited thereto.

For the external compensation of the sub-pixel on the panel, the component to be sensed may be an organic light-emitting diode or a thin film-transistor (TFT). The driving integrated circuit can compensate the parameters of the organic light emitting diode and the thin film transistor when generating display data according to the sensing result of these components. Please refer to Figures 6A to 6D. Figures 6A to 6D are schematic diagrams showing the detailed programming and sensing operations of the sub-pixels in Figure 2. 6A to 6D are diagrams showing subpixels P1 to P3 and their corresponding wires L1 to L4, and the wires L1 to L4 are coupled to a driving integrated circuit (not shown). Each of the sub-pixels P1 to P3 includes an organic light-emitting diode LED 1, a driving thin film transistor T1, a capacitor, and a plurality of control thin film transistors functioning as a switch. The sub-pixels P1 to P3 have a P-type structure in which the driving film transistor T1 is a P-type Metal-Oxide Semiconductor Field-Effect Transistor (PMOSFET).

As shown in FIG. 6A, the driving integrated circuit programs the sub-pixels P1 and P3 through the wires L1 and L3 at a very low voltage to sense the organic light-emitting diode LED1 through the wires L2 and L4. In this example, the sensing operation is performed on the organic light-emitting diode LEDs 1 in the sub-pixels P1 and P3. In detail, in the compensation mode, the control signals Scan[N] and FB[N] turn on the corresponding control film transistor, and the control signal EM[N] turns off the corresponding control film transistor. Therefore, the extremely low voltage input from the wires L1 and L3 is transmitted to the gate of the driving film transistor T1 to turn on the driving film transistor T1 and operate the driving film transistor T1 in a linear region, at this time driving the film Transistor T1 can be considered a fully conductive switch. In this case, the sensing signals input from the wires L2 and L4 can be driven into the organic light-emitting diodes LED1 of the sub-pixels P1 and P3 by driving the thin film transistor T1 to obtain the electrical characteristics of the organic light-emitting diode LED1. For example, the driving integrated circuit can generate a voltage signal on the sensing line L2 to sense the current through the organic light emitting diode LED1 or generate a current signal on the sensing line L2 to sense the organic light emitting diode. The voltage of the body LED1.

It is worth noting that the above sensing operation produces a higher voltage on the sensing lines (such as wires L2 and L4), which will turn off the sub-pixels adjacent to the sub-pixels to be sensed (eg, sub-pixel P2). Driving the thin film transistor. In addition, in the non-sensing sub-pixel, the gate and the capacitor of the driving thin film transistor can isolate the sensing signal on the sensing line, and thus do not interfere with the sensing operation in the sub-pixel to be sensed. For example, in the sub-pixel P2 of FIG. 6A, the sensing signal is transmitted to the gate and the capacitor of the driving thin film transistor T1, and the sensing result is not affected, and the driving thin film transistor T1 receives the higher voltage. The turn-off is such that the programming signal input from the line L3 does not enter the organic light-emitting diode LED 1 in the sub-pixel P2. As shown in Figures 6A to 6D, the "cross" on the thin film transistor indicates that the thin film transistor is turned off or off. Therefore, the sub-pixel P2 can isolate the programming and sensing operations in the sub-pixels P1 and P3, and can prevent the operation of different sub-pixels from interfering with each other.

In an exemplary embodiment of the invention, the supply voltage VDD is 8V and the ground voltage VSS is 0V. The programming signal input from the wires L1 and L3 is a very low voltage, such as 0V, so that the driving thin film transistors in the sub-pixels P1 and P3 operate in the linear region. The voltage of the sense signal on conductors L2 and L4 is equal to 6V. In this example, the programming and sensing operations are for the organic light-emitting diode LEDs 1 located in the sub-pixels of the odd rows.

As shown in FIG. 6B, the driving integrated circuit programs the sub-pixels P1 and P3 through the wires L1 and L3 at a relatively low voltage to sense the driving film transistor T1 through the wires L2 and L4. In this example, the sensing operation is performed on the driving thin film transistor T1 in the sub-pixels P1 and P3. In detail, in the compensation mode, the control signals Scan[N] and FB[N] turn on the corresponding control film transistor, and the control signal EM[N] turns off the corresponding control film transistor. Therefore, the relatively low voltage input from the wires L1 and L3 is transmitted to the gate of the driving thin film transistor T1 to turn on the driving thin film transistor T1 and operate the driving thin film transistor T1 in the saturation region. In this case, the sensing signals input from the wires L2 and L4 can be driven into the organic light-emitting diodes LED1 in the sub-pixels P1 and P3 by driving the thin film transistor T1, and the sensing voltage and current will follow the operation in the saturation region. The current/voltage characteristics of the metal oxide half field effect transistor. Therefore, the driving integrated circuit can simultaneously obtain the electrical characteristics of the driving thin film transistor T1 and the organic light emitting diode LED 1. By subtracting the portion of the organic light-emitting diode LED 1 (which can be obtained in the embodiment of FIG. 6A), the integrated circuit can be driven to obtain the electrical characteristics of the driving thin film transistor T1.

Similarly, in the sub-pixel P2 shown in FIG. 6B, the sensing signal having a higher voltage is transmitted to the gate and the capacitor of the driving thin film transistor T1, which does not affect the sensing result, and drives the thin film transistor T1. The higher voltage is received and turned off, so that the programming signal input from the wire L3 does not enter the organic light emitting diode LED1 in the subpixel P2. Therefore, the sub-pixel P2 can isolate the programming and sensing operations in the sub-pixels P1 and P3, and can prevent the operation of different sub-pixels from interfering with each other.

In an exemplary embodiment of the invention, the supply voltage VDD is 8V and the ground voltage VSS is 0V. The programming signal input from the wires L1 and L3 is a relatively low voltage, such as 4V, so that the driving thin film transistors in the subpixels P1 and P3 operate in the saturation region. The voltage of the sense signal on conductors L2 and L4 is equal to 6V. In this example, the programming and sensing operations are performed on the driving thin film transistor T1 and the organic light emitting diode LED1 in the sub-pixels of the odd rows, and the driving thin film can be obtained after subtracting the portion of the organic light emitting diode LED1. Information about transistor T1.

As shown in FIG. 6C, the driving integrated circuit programs the sub-pixel P2 through the wire L2 at a very low voltage to sense the organic light-emitting diode LED1 through the wire L3. In this example, the sensing operation is performed on the organic light-emitting diode LED 1 in the sub-pixel P2. More specifically, the programming and sensing operations are directed to the organic light-emitting diode LEDs 1 located in the sub-pixels of the even rows. Compared with the embodiment of FIG. 6A, in the embodiment of FIG. 6C, the wires play different roles, that is, the wires (eg, L1, L3, ..., etc.) located in the odd rows can be used as the sensing lines. To receive the electrical characteristics of the organic light-emitting diode LED1 in the sub-pixels of the even-numbered rows, the wires (such as L2, L4, ..., etc.) located in even rows can be used as data lines for the sub-rows. The pixels are programmed. According to the content of FIG. 6C and the above description, those skilled in the art should be able to infer the detailed programming and sensing operation modes of the organic light-emitting diode LED 1 in the sub-pixels of the even-numbered rows, and details are not described herein.

As shown in Fig. 6D, the driving integrated circuit programs the sub-pixel P2 at a relatively low voltage through the wire L2 to sense the driving film transistor T1 through the wire L3. In this example, the sensing operation is performed on the driving thin film transistor T1 in the sub-pixel P2. More specifically, the programming and sensing operations are directed to the driving thin film transistor T1 located in the sub-pixels of the even rows. Compared with the embodiment of FIG. 6B, in the embodiment of FIG. 6D, the wires play different roles, that is, the wires (such as L1, L3, ..., etc.) located in the odd rows can be used as the sensing lines. To receive the electrical characteristics of the driving film transistor T1 in the sub-pixels of the even rows, the wires in the even rows (such as L2, L4, ..., etc.) can be used as data lines for sub-pictures located in even rows. Programming. According to the content of FIG. 6D and the above description, those skilled in the art should be able to infer the detailed programming and sensing operation modes of the driving thin film transistor T1 in the sub-pixels of the even rows, and details are not described herein.

It should be noted that the programming and sensing operations of the present invention are also applicable to sub-pixels having an N-type structure, as detailed below.

Please refer to the 7A-7D drawings, and the 7A-7D diagram is a schematic diagram of the detailed programming and sensing operation of the sub-pixel in FIG. 7A to 7D are diagrams showing subpixels P1 to P3 and their corresponding wires L1 to L4, and wires L1 to L4 are coupled to a driving integrated circuit (not shown). Each of the sub-pixels P1 to P3 includes an organic light-emitting diode LED 2, a driving thin film transistor T2, a capacitor, and a plurality of control thin film transistors functioning as a switch. The sub-pixels P1 to P3 have an N-type structure in which the driving film transistor T2 is an N-type Metal-Oxide Semiconductor Field-Effect Transistor (NMOSFET).

As shown in FIG. 7A, the driving integrated circuit programs the sub-pixels P1 and P3 through the wires L1 and L3 at a relatively low voltage to sense the organic light-emitting diode LED 2 through the wires L2 and L4. In this example, the sensing operation is performed on the organic light-emitting diode LEDs 2 in the sub-pixels P1 and P3. In detail, in the compensation mode, the control signals Scan[N] and FB_O[N] turn on the corresponding control film transistor, and the control signal FB_E[N] turns off the corresponding control film transistor. Therefore, the relatively low voltage input from the wires L1 and L3 is transmitted to the gate of the driving film transistor T2 to turn off the driving film transistor T2 and operate the driving film transistor T2 in the cut-off region. The driving film transistor T2 can be regarded as a completely disconnected switch. In this case, the sensing signals input from the wires L2 and L4 can enter the organic light-emitting diode LEDs 2 in the sub-pixels P1 and P3 without being disturbed by the driving film transistor T2, thereby obtaining the organic light-emitting diode. The electrical characteristics of the body LED2.

It is worth noting that the above sensing operation produces a higher voltage on the sensing lines (such as wires L2 and L4), which will turn on the sub-pixels adjacent to the sub-pixels to be sensed (eg, sub-pixel P2). Driving the thin film transistor. However, the control signal FB_E[N] can turn off its corresponding control film transistor to prevent the programming signal from entering the non-sensing sub-pixel. In addition, in the non-sensing sub-pixel, the gate and the capacitor of the driving thin film transistor can isolate the sensing signal on the sensing line, and thus do not interfere with the sensing operation in the sub-pixel to be sensed. For example, in the sub-pixel P2 of FIG. 7A, the sensing signal is transmitted to the gate and the capacitor of the driving thin film transistor T2, and the sensing result is not affected, and the rightmost control film in the sub-pixel P2 is electrically The crystal is turned off by the control signal FB_E[N] so that the programming signal input from the wire L3 does not enter the organic light-emitting diode LED 2 in the sub-pixel P2. Similarly, as shown in Figures 7A to 7D, the "cross" on the thin film transistor indicates that the thin film transistor is turned off or off. Therefore, the sub-pixel P2 can isolate the programming and sensing operations in the sub-pixels P1 and P3, and can prevent the operation of different sub-pixels from interfering with each other.

In an exemplary embodiment of the invention, the supply voltage VDD is 8V and the ground voltage VSS is 0V. The programming signal input from the wires L1 and L3 is a relatively low voltage, such as 3V, which turns off the driving thin film transistors in the sub-pixels P1 and P3. The voltage of the sense signal on conductors L2 and L4 is equal to 5V. In this example, the programming and sensing operations are for the organic light-emitting diode LEDs 2 located in the sub-pixels of the odd rows.

As shown in FIG. 7B, the driving integrated circuit programs the sub-pixels P1 and P3 through the wires L1 and L3 at a relatively high voltage to sense the driving film transistor T2 through the wires L2 and L4. In this example, the sensing operation is performed on the driving thin film transistor T2 in the sub-pixels P1 and P3. In detail, in the compensation mode, the control signals Scan[N] and FB_O[N] turn on the corresponding control film transistor, and the control signal FB_E[N] turns off the corresponding control film transistor. Therefore, the relatively high voltage input from the wires L1 and L3 is transmitted to the gate of the driving film transistor T2 to turn on the driving film transistor T2 and operate the driving film transistor T2 in the saturation region. In this case, the sensing signals input from the wires L2 and L4 can enter the driving film transistor T2 in the sub-pixels P1 and P3, and the sensing voltage and current follow the gold-oxygen half-field effect transistor operating in the saturation region. Current/voltage characteristics. Therefore, the driving integrated circuit can obtain the electrical characteristics of the driving thin film transistor T2.

It is worth noting that the above sensing operation produces a lower voltage on the sensing lines (such as wires L2 and L4), which lowers the sub-pixels adjacent to the sub-pixels to be sensed (eg, sub-pixel P2). Driving the thin film transistor. In addition, in the non-sensing sub-pixel, the gate and the capacitor of the driving thin film transistor can isolate the sensing signal on the sensing line, and thus do not interfere with the sensing operation in the sub-pixel to be sensed. For example, in the sub-pixel P2 of FIG. 7B, the sensing signal with a lower voltage is transmitted to the gate and the capacitor of the driving thin film transistor T2, and does not affect the sensing result, and drives the thin film transistor T2 to receive. When it is turned off to a lower voltage, the control film transistor controlled by the control signal FB_E[N] is also turned off, so that the programming signal input from the wire L3 does not enter the sub-pixel P2. Therefore, the sub-pixel P2 can isolate the programming and sensing operations in the sub-pixels P1 and P3, and can prevent the operation of different sub-pixels from interfering with each other.

In an exemplary embodiment of the invention, the supply voltage VDD is 8V and the ground voltage VSS is 0V. The programming signal input from the wires L1 and L3 is a relatively high voltage, such as 5V, so that the driving thin film transistors in the subpixels P1 and P3 operate in the saturation region. The voltage of the sense signal on conductors L2 and L4 is equal to 3V. In this example, the programming and sensing operations are directed to the driving thin film transistor T2 located in the sub-pixels of the odd rows.

As shown in FIG. 7C, the driving integrated circuit programs the sub-pixel P2 through the wire L2 at a relatively low voltage to sense the organic light-emitting diode LED 2 through the wire L3. In this example, the sensing operation is performed on the organic light-emitting diode LED 2 in the sub-pixel P2. More specifically, the programming and sensing operations are for organic light-emitting diode LEDs 2 located in sub-pixels of even rows. Compared with the embodiment of FIG. 7A, in the embodiment of FIG. 7C, the wires play different roles, that is, the wires (eg, L1, L3, ..., etc.) located in the odd rows can be used as the sensing lines. To receive the electrical characteristics of the organic light-emitting diode LED2 in the sub-pixels of the even-numbered rows, the wires (such as L2, L4, ..., etc.) located in even rows can be used as data lines for the sub-rows. The pixels are programmed. According to the content of FIG. 7C and the above description, those skilled in the art should be able to infer the detailed programming and sensing operation modes of the organic light-emitting diode LED 2 located in the sub-pixels of the even-numbered rows, and details are not described herein.

As shown in Fig. 7D, the drive integrated circuit programs the sub-pixel P2 through a relatively high voltage through the wire L2 to sense the drive film transistor T2 through the wire L3. In this example, the sensing operation is performed on the driving film transistor T2 in the sub-pixel P2. More specifically, the programming and sensing operations are directed to driving thin film transistors T2 located in sub-pixels of even rows. Compared with the embodiment of FIG. 7B, in the embodiment of FIG. 7D, the wires play different roles, that is, the wires (such as L1, L3, ..., etc.) located in the odd rows can be used as the sensing lines. To receive the electrical characteristics of the driving film transistor T2 in the sub-pixels of the even rows, the wires in the even rows (such as L2, L4, ..., etc.) can be used as data lines for sub-pictures located in even rows. Programming. According to the content of the 7D figure and the above description, those skilled in the art should be able to infer the detailed programming and sensing operation modes of the driving film transistor T2 in the sub-pixels of the even-numbered rows, and details are not described herein.

The programming and sensing operations described above with respect to the organic light emitting diode display system can be summarized as an external compensation process 80, as shown in FIG. The external compensation process 80 can be performed in a drive integrated circuit that includes the following steps:

Step 800: Start.

Step 802: program, in a first period, a first component of the first sub-pixel of the plurality of sub-pixels through a first wire, and sense the first component through a second wire .

Step 804: program, in a second period, a second component of the second sub-pixel of the plurality of sub-pixels through the second wire, and pass the first wire or a third wire to the second component Perform sensing.

Step 806: End.

For detailed operations and changes of the external compensation process 80, reference may be made to the above description, and details are not described herein.

In summary, the present invention provides an external compensation method for a panel and a drive integrated circuit that can perform an external compensation method on the panel. According to the external compensation method, each row of wires can be used as a data line or a sensing line, which is shared by adjacent sub-pixels. The components located in the odd row subpixels and the components located in the even row subpixels are alternately programmed and sensed. In other words, elements located in odd-line sub-pixels can be programmed and sensed during the first period, while elements located in even-numbered sub-pixels can be programmed and sensed during the second period. In the driving integrated circuit, the analog digital converter can be shared by two adjacent wires, which can reduce the number of analog digital converters in the driving integrated circuit, thereby reducing the cost of driving the integrated circuit. In addition to this, the external compensation method of the present invention can be applied to sub-pixels of any structure, such as a P-type structure or an N-type structure. According to the external compensation method of the present invention, if the panel contains N rows of sub-pixels, only N or N+1 wires are needed to realize data display and external compensation operation, and the number of pins for driving the integrated circuit can also be significantly reduce. The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

<TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> 100 </td><td> panel</td></tr><tr>< Td> 20 </td><td> Organic Light Emitting Diode Display System</td></tr><tr><td> 200 </td><td> Panel</td></tr><tr ><td> 210 </td><td> Drive Integrated Circuit</td></tr><tr><td> L1~L5 </td><td> Conductor</td></tr>< Tr><td> P1~P4 </td><td> Subpixels</td></tr><tr><td> 30 </td><td> Organic Light Emitting Diode Display System</td ></tr><tr><td> 300 </td><td> Panel</td></tr><tr><td> 310 </td><td> Drive Integrated Circuit</td> </tr><tr><td> L1'~L4' </td><td> wire</td></tr><tr><td> P1'~P4' </td><td> Pixel</td></tr><tr><td> 40 </td><td> Organic Light Emitting Diode Display System</td></tr><tr><td> 400 </td> <td> panel</td></tr><tr><td> 410 </td><td> drive integrated circuit</td></tr><tr><td> DL1~DL4 </td ><td> Wire</td></tr><tr><td> B1~B4 </td><td> Output Buffer</td></tr><tr><td> DAC1~DAC4 < /td><td> Digital Analog Converter</td></tr><tr><td> ADC1~ADC2 </td><td> Analog Digital Converter</td></tr ><tr><td> MUX1~MUX2 </td><td> Multiplexer</td></tr><tr><td> SW1~SW8 </td><td> Switch</td> </tr><tr><td> LED1, LED2 </td><td> Organic Light Emitting Diodes</td></tr><tr><td> T1, T2 </td><td> Thin film transistor </td></tr><tr><td> Scan[N], EM[N], FB[N], FB_O[N], FB_E[N] </td><td> control signal </td></tr><tr><td> VDD </td><td> Power Supply Voltage </td></tr><tr><td> VSS </td><td> Ground Voltage </ Td></tr><tr><td> 80 </td><td> External Compensation Process</td></tr><tr><td> 800~806 </td><td> Step </ Td></tr></TBODY></TABLE>

Figure 1 is a schematic diagram of a panel for performing common external compensation methods. FIG. 2 is a schematic diagram of an organic light emitting diode display system according to an embodiment of the present invention. FIG. 3 is a schematic diagram of another organic light emitting diode display system according to an embodiment of the present invention. 4 is a schematic diagram showing the circuit structure of an organic light emitting diode display system and a driving integrated circuit thereof according to an embodiment of the present invention. Figure 5 is a waveform diagram of the switch of Figure 4. Figures 6A to 6D are schematic diagrams showing the detailed programming and sensing operations of the sub-pixels in Figure 2. Figures 7A to 7D are schematic diagrams showing the detailed programming and sensing operations of the sub-pixels in Figure 2. Figure 8 is a schematic diagram of an external compensation process according to an embodiment of the present invention.

<TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> 80 </td><td> External Compensation Process</td></tr><tr ><td> 800~806 </td><td> Steps</td></tr></TBODY></TABLE>

Claims (10)

  1. An external compensation method for an element on a board, the panel comprising a plurality of sub-pixels, the external compensation method comprising: in a first period, transmitting a plurality of sub-pixels through a first wire a first component of a sub-pixel is programmed to sense the first component through a second wire; and in the second period, the second plurality of sub-pixels are transmitted through the second wire A second component of the two sub-pixels is programmed and sensed by the first wire or a third wire.
  2. The external compensation method of claim 1, wherein the second sub-pixel is adjacent to the first sub-pixel.
  3. The external compensation method of claim 1, wherein the first component and the second component are an Organic Light-Emitting Diode (OLED) or a thin film transistor (Thin-Film) in the panel. Transistor, TFT).
  4. The external compensation method of claim 1, wherein the plurality of sub-pixels are divided into a first group of sub-pixels and a second group of sub-pixels, wherein the component of the first group of sub-pixels is Programming and sensing are performed during the first period, and the component located in the second set of sub-pixels is programmed and sensed during the second period.
  5. The external compensation method of claim 4, wherein the first group of sub-pixels comprises a sub-pixel of the plurality of sub-pixels located in an odd-numbered pixel, the second group of sub-pixels comprising the plurality of sub-pixels A sub-pixel located in an even line.
  6. A driver integrated circuit (Driver IC) for performing external compensation on the panel, the driver integrated circuit comprising: a plurality of wires; a first digital analog converter (Digital to An analog output (DAC) and a first output buffer coupled to a first one of the plurality of wires; a second digital analog converter and a second output buffer coupled to the plurality of wires a second wire; a multiplexer; an analog to digital converter (ADC) coupled to the first wire and the second wire through the multiplexer; a first switch, coupled Connected between the first wire and the first output buffer; a second switch coupled between the first wire and the multiplexer; a third switch coupled to the second wire And a multiplexer coupled between the second wire and the second output buffer.
  7. The driving integrated circuit of claim 6, wherein the first switch, the second switch, the third switch, the fourth switch, and the multiplexer control the driving integrated circuit selectivity Programming a first component of a first sub-pixel on the panel through the first wire and sensing the first component through the second wire, or transmitting the first component through the second wire A second component of the second subpixel is programmed and senses the second component through the first wire or a third wire.
  8. The driving integrated circuit of claim 6, wherein the plurality of wires are divided into a first And a second set of wires, and each of the first set of wires is adjacent to one of the second set of wires.
  9. The driving integrated circuit of claim 8, wherein the driving integrated circuit programs the plurality of first components on the panel through the first set of wires and transmits the second set of wire pairs in a first period Sensing the plurality of first components, and programming a plurality of second components on the panel through the second set of wires during a second period and performing the plurality of second components through the first set of wires Sensing.
  10. The driving integrated circuit of claim 8, wherein the first set of wires comprises wires of the plurality of wires located in odd rows, and the second group of wires comprises wires of the plurality of wires located in even rows.
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US15/187,809 2016-06-21
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CN103236237B (en) * 2013-04-26 2015-04-08 京东方科技集团股份有限公司 Pixel unit circuit and compensating method of pixel unit circuit as well as display device
CN104658474A (en) * 2013-11-20 2015-05-27 乐金显示有限公司 Organic light emitting display and method of compensation for threshold voltage thereof
CN103177685B (en) * 2011-12-26 2015-06-03 乐金显示有限公司 OLED display device and method for sensing characteristic parameters of pixel driving circuits

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102968954A (en) * 2011-08-30 2013-03-13 乐金显示有限公司 Organic light emitting diode display device for sensing pixel current and method for sensing pixel current thereof
CN103177685B (en) * 2011-12-26 2015-06-03 乐金显示有限公司 OLED display device and method for sensing characteristic parameters of pixel driving circuits
CN103236237B (en) * 2013-04-26 2015-04-08 京东方科技集团股份有限公司 Pixel unit circuit and compensating method of pixel unit circuit as well as display device
CN104658474A (en) * 2013-11-20 2015-05-27 乐金显示有限公司 Organic light emitting display and method of compensation for threshold voltage thereof

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