KR20200070996A - Source Driver IC for Sensing Characteristic of Driving Transistor - Google Patents

Abstract

A source drive IC for sensing characteristics of a driving transistor according to one aspect of the present invention, capable of removing noise generated when electrical characteristics of the driving transistor are sensed, includes: a sensing block connected to pixels through m (m is an integer of 2 or more) sensing channels and configured to acquire a reference sensing value through one reference sensing channel connected to a pixel, to which a source signal for sensing a reference for sensing operations by sensing the pixel m times during an effective sensing section, and acquire an effective sensing value through (m-1) effective sensing channels connected to the pixel, to which the source signal for effective sensing; and a sensing data calculating part configured to calculate a real sensing value for sensing channels by using a difference between the effective sensing value acquired through the effective sensing channel and the reference sensing values acquired through the reference sensing channel, and the pixel, to which the source signal for sensing a reference varies for the sensing operations.

Description

Source Driver IC for Sensing Characteristic of Driving Transistor

The present specification relates to a display device, and more particularly, to a source drive IC capable of sensing characteristics of a driving transistor.

The active matrix type organic light emitting display device includes an organic light emitting diode (hereinafter referred to as “OLED”) that emits light by itself, and has a fast response speed, high light emission efficiency, high brightness, and a wide viewing angle.

The self-luminous device OLED includes an anode electrode and a cathode electrode, and an organic compound layer (HIL, HTL, EML, ETL, EIL) formed therebetween. The organic compound layer includes a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and an electron injection layer (Electron Injection layer, EIL). When a driving voltage is applied to the anode electrode and the cathode electrode, holes passing through the hole transport layer (HTL) and electrons passing through the electron transport layer (ETL) are moved to the emission layer (EML) to form excitons, and as a result, the emission layer (EML) Visible light is generated.

The organic light emitting display device arranges pixels including OLEDs in a matrix form and adjusts the luminance of the pixels according to the gradation of video data. Each of the pixels includes a driving TFT (thin film transistor) that controls a driving current flowing through the OLED according to a voltage Vgs between the gate electrode and the source electrode. The electrical characteristics of the driving transistor, such as threshold voltage and mobility, may deteriorate with the lapse of driving time, resulting in variations for each pixel. When the electrical characteristics of the driving transistor are different for each pixel, luminance between pixels is different for the same video data, so it is difficult to implement a desired image.

Among the methods for compensating for the variation in the electrical characteristics of the driving transistor, the external compensation method is driven by measuring the sensing value corresponding to the electrical characteristics of the driving transistors through the sensing unit and modulating the video data input from the outside using the sensing value. Compensate for variations in electrical characteristics of transistors.

In the case of such an external compensation method, an accurate value cannot be sensed because the sensing value sensed by the sensing unit includes white noise, common noise generated in the chip operation and environment, and an offset of the sensing unit. There is a problem that a dim phenomenon may occur.

The present invention is to solve the above-mentioned problems, and it is a technical problem to provide a source drive IC for sensing characteristics of a driving transistor capable of removing noise generated when sensing electrical characteristics of the driving transistor.

In addition, another object of the present invention is to provide a source drive IC for sensing characteristics of a driving transistor capable of improving sensing efficiency.

In addition, another object of the present invention is to provide a source drive IC for sensing characteristics of a driving transistor capable of reducing the number of sensing units or sensing channels for sensing electrical characteristics of the driving transistor.

A source drive IC for sensing characteristics of a driving transistor according to an aspect of the present invention for achieving the above object is connected to pixels through m (m is an integer of 2 or more) sensing channels, and the pixels during an effective sensing period By sensing m times, a reference sensing value is obtained through one reference sensing channel connected to a pixel to which a source signal for reference sensing is applied for each sensing difference, and m-1 effective sensing connected to a pixel to which a source signal for effective sensing is applied. A sensing block for obtaining an effective sensing value through a channel; And a sensing data calculation unit for calculating a real sensing value for each sensing channel by using a difference between an effective sensing value obtained through the effective sensing channel and a reference sensing value obtained through the reference sensing channel for each sensing session. In addition, a pixel to which the reference sensing source signal is applied is variable for each sensing difference.

The source drive IC for sensing the characteristics of the driving transistor according to an aspect of the present invention for achieving the above object is any one of an odd sensing channel and an even sensing channel adjacent to each other in 2m sensing channels. A plurality of mux to select (MUX); During an effective sensing period, m sensing channels connected through the plurality of mUXs are sensed m times, and a reference sensing value is acquired and valid through one reference sensing channel connected to a pixel to which a source signal for reference sensing is applied for each sensing difference. A sensing block for obtaining an effective sensing value through m-1 effective sensing channels connected to a pixel to which a sensing source signal is applied; And a sensing data calculation unit for calculating a real sensing value for each sensing channel by using a difference between an effective sensing value obtained through the effective sensing channel and a reference sensing value obtained through the reference sensing channel for each sensing session. In addition, a pixel to which the reference sensing source signal is applied is variable for each sensing difference.

According to the present invention, it is possible to accurately sense the electrical characteristics of the driving transistor by removing white noise, common noise, or offset generated when sensing the electrical characteristics of the driving transistor, thereby accurately compensating for the deviation of the electrical characteristics of the driving transistor. There is an effect that can prevent the occurrence of dim phenomenon.

In addition, according to the present invention, when sensing the electrical characteristics of the driving transistor, it is possible to improve the sensing efficiency, so that a relatively high sensing accuracy can be secured even through a small number of sensing times.

In addition, according to the present invention, the number of sensing units or sensing channels required for sensing the electrical characteristics of the driving transistor can be reduced, thereby reducing the size of the display device and reducing the amount of data transmitted to the timing controller. It works.

1 is a view showing a display device to which the source drive IC according to the present invention is applied.
2 is a view showing a pixel configuration according to an embodiment of the present invention.
3 is a diagram schematically showing the configuration of a source driver IC and a display panel according to a first embodiment of the present invention.
4 is a block diagram schematically showing the configuration of a sensing block according to a first embodiment of the present invention.
5 is a table showing a sensing method by a sensing block according to a first embodiment of the present invention.
6 is a diagram showing a timing diagram of a sensing method using a sensing block according to a first embodiment of the present invention.
7 is a block diagram showing the configuration of a sensing unit of the current sensing method according to an embodiment of the present invention.
8 is a table showing a sensing method by a sensing block according to a second embodiment of the present invention.
9 is a timing diagram showing a sensing method by a sensing block according to a second embodiment of the present invention.
10 is a view showing the configuration of a sensing block according to a third embodiment of the present invention.
11 is a timing diagram showing a sensing method using a sensing block according to a third embodiment of the present invention.
12 is a view showing the configuration of a sensing block according to a modification of the third embodiment.
13 is a diagram schematically showing the configuration of a source driver IC and a display panel according to a fourth embodiment of the present invention.
14 is a timing diagram of a sensing method using a sensing block according to a modified embodiment of the fourth embodiment.

Throughout the specification, the same reference numerals refer to substantially the same components. In the following description, detailed descriptions of components and functions known in the technical field of the present invention may be omitted if not related to the core configuration of the present invention. The meaning of the terms described in this specification should be understood as follows.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only the embodiments allow the disclosure of the present invention to be complete, and the ordinary knowledge in the technical field to which the present invention pertains. It is provided to fully inform the holder of the scope of the invention, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for describing the embodiments of the present invention are exemplary and the present invention is not limited to the illustrated matters. The same reference numerals refer to the same components throughout the specification. In addition, in the description of the present invention, when it is determined that detailed descriptions of related known technologies may unnecessarily obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

When'include','have','consist of' and the like mentioned in this specification are used, other parts may be added unless'~man' is used. When a component is expressed as a singular number, the plural number is included unless otherwise specified.

In interpreting the components, it is interpreted as including the error range even if there is no explicit description.

In the case of a description of a time relationship, for example,'after','following','~after','~before', etc. When a temporal sequential relationship is described,'right' or'direct' It may also include cases that are not continuous unless it is used.

The first, second, etc. are used to describe various components, but these components are not limited by these terms. These terms are only used to distinguish one component from another component. Therefore, the first component mentioned below may be the second component within the technical spirit of the present invention.

It should be understood that the term “at least one” includes all possible combinations from one or more related items. For example, the meaning of “at least one of the first item, the second item, and the third item” means 2 of the first item, the second item, and the third item, as well as the first item, the second item, and the third item, respectively. It can mean any combination of items that can be presented from more than one dog.

Each of the features of the various embodiments of the present invention may be partially or wholly combined or combined with each other, technically various interlocking and driving is possible, and each of the embodiments may be independently performed with respect to each other or may be implemented together in an association relationship. It might be.

Hereinafter, embodiments of the present specification will be described in detail with reference to the accompanying drawings.

1 is a view showing a display device to which the source drive IC according to the present invention is applied.

Referring to FIG. 1, the display apparatus 100 according to an embodiment of the present invention includes a display panel 10, a timing controller 11, a source driving circuit 12, and a gate driving circuit 13.

The display panel 10 displays image data RGB' input from the timing controller 11. A plurality of data lines 14A, a plurality of sensing lines 14A, and a plurality of gate lines 15 are formed on the display panel 10. The plurality of data lines 14A and the plurality of sensing lines 14B may be formed to cross the plurality of gate lines 15.

Pixels P are arranged in a matrix in a region where the plurality of data lines 14A and the plurality of gate lines 15 intersect. In one embodiment, each pixel P may include an OLED (Organic Light Emitting Diode, not shown) and one or more thin film transistors (TFT, not shown).

The pixel P is connected to any one of the data lines 14A, one of the sensing lines 14B, and one of the gate lines 15. The pixel P receives a source signal from the data line 14A in response to a gate pulse input through the gate line 15, and a driving transistor included in each pixel P through the sensing line 14B ( (Not shown). In one embodiment, the characteristic information of the driving transistor may include a threshold voltage or mobility of the driving transistor.

The pixel P is supplied with a high potential driving voltage EVDD and a low potential driving voltage EVSS from a power generator (not shown).

An example of a pixel P configuration is illustrated in FIG. 2. Referring to FIG. 2, the pixel P according to the present invention may include a first switching transistor ST1, a second switching transistor ST2, a storage capacitor Cst, a driving transistor DT, and an OLED. .

The first switching transistor ST1 applies the source signal Vdata-D/Vdata-S from the data line 14A to the first node N1 in response to the gate pulse SCAN. The first switching transistor ST1 includes a gate electrode connected to the gate line 15, a drain electrode connected to the data line 14A, and a source electrode connected to the first node N1.

The second switching transistor ST2 switches the current flow between the second node N2 and the sensing line 14B in response to the gate pulse SCAN. The second switching transistor ST2 includes a gate electrode connected to the gate line 15, a drain electrode connected to the sensing line 14B, and a source electrode connected to the second node N2.

The storage capacitor Cst is connected between the first node N1 and the second node N2.

The driving transistor DT controls the amount of current input to the OLED according to the gate-source voltage Vgs. The driving transistor DT includes a gate electrode connected to the first node N1, a drain electrode connected to the input terminal of the high potential driving voltage EVDD, and a source electrode connected to the second node N2.

The OLED includes an anode electrode connected to the second node N2, a cathode electrode connected to the input terminal of the low potential driving voltage EVSS, and an organic compound layer positioned between the anode electrode and the cathode electrode.

The pixel structure as shown in FIG. 2 is only one example to help understanding of the present invention, and since the pixel structure can be variously modified, the technical idea of the present invention is not limited to this embodiment.

Referring back to FIG. 1, the timing controller 11 controls the operation of the source driving circuit 12 and the gate driving circuit 12. Specifically, the timing controller 11 is a source driving circuit based on timing signals such as a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), a dot clock signal (DCLK), and a source enable signal (SE). A source control signal (SDC) for controlling the operation timing of 12) and a gate control signal (GDC) for controlling the operation timing of the gate driving circuit 13 are generated.

In one embodiment, the timing controller 11 may be driven in a source driving assembly so that each pixel P may be driven in a sensing mode that senses a normal mode for displaying image data and characteristic information of a driving transistor to obtain a sensing value. The operation of the furnace 12 and the gate driving circuit 13 can be controlled. At this time, the sensing mode may be performed during a power-on process before driving a normal mode or a power-off process after a normal mode. In another embodiment, the sensing mode may be performed in vertical blank periods during normal mode driving.

The timing controller 11 uses predetermined reference signals (driving power enable signal, vertical synchronization signal, source enable signal, etc.) to operate the source driving circuit 12 and the gate driving circuit 13 in a normal mode and a sensing mode. Based on this, the normal mode and the sensing mode can be distinguished, and a source control signal (SDC) and a gate control signal (GDC) can be generated according to each mode.

In addition, the timing controller 11 converts the image data RGB input from the outside for driving the normal mode into image data RGB' of a form that the source driving circuit 12 can process, and the source driving circuit 12 ). In addition, the timing controller 11 generates sensing data for sensing characteristic information of the driving transistor of each pixel P for driving the sensing mode and provides it to the source driving circuit 12.

In one embodiment, the sensing data may include data for effective sensing for effective sensing of each pixel P and reference sensing data for reference sensing of each pixel P. In one embodiment, the reference sensing data may be data capable of suppressing generation of pixel current when a source signal corresponding to the reference sensing data is input to each pixel. For example, the reference sensing data may be image data corresponding to black gradation.

Meanwhile, the timing controller 11 derives a compensation value for compensating for a change in the electrical characteristics of the driving transistor included in each pixel P based on the sensing value obtained in the sensing mode, and based on the compensation value, the source driving circuit (12) modulates the video data to be provided.

Specifically, the timing controller 11 applies the real sensing value RDS transmitted from the source driving circuit 12 when the sensing mode is driven to a pre-stored compensation algorithm, and the threshold voltage deviation and movement of the driving transistor included in each pixel are shifted. After deriving the amount of change in degrees, a compensation value capable of compensating for the amount of change is derived. The compensation value may be stored in a memory (not shown), and whenever a new compensation value is derived, the compensation value stored in the memory may be updated with a new compensation value.

The timing controller 11 may modulate the image data by adding or multiplying the compensation value stored in the memory to the image data during normal driving.

The gate driving circuit 13 generates a first type gate pulse for displaying image data based on a gate control signal (GDC) during normal mode driving, and then generates the first type gate pulse for each gate line 15. In order to feed.

The gate driving circuit 13 generates a second type gate pulse for sensing each pixel P based on the gate control signal GDC when the sensing mode is driven, and then generates the generated second type gate pulse for each gate line. The fields 15 are sequentially supplied.

In one embodiment, the on-type pulse period of the second type gate pulse may be wider than that of the first type gate pulse. The on-pulse period of the second type gate pulse corresponds to one line sensing on time, where one line sensing on time senses pixels P included in one horizontal line (L#1 to L#p) at the same time. Means the scan time required.

The source driving circuit 12 is connected to a plurality of data lines 14A and operates in a normal mode or a sensing mode according to the mode control of the timing controller 11. As shown in FIG. 1, the source driving circuit 12 includes a plurality of source driver ICs SDIC#1 to SDIC#k.

When operating in the normal mode, the source driver IC (SDIC#1 to SDIC#k) converts the image data supplied from the timing controller 11 to each pixel P into a source signal (Vdata_D) for image display, and converts the corresponding data line. (14A).

When operating in the sensing mode, the source driver ICs SDIC#1 to SDIC#k convert sensing data supplied from the timing controller 11 to each pixel P into a sensing source signal Vdata_S, and for sensing The source signal is supplied to the corresponding data line 14A to sense the characteristics of the driving transistor included in each pixel P. The source driver IC (SDIC#1 to SDIC#k) transmits the real sensing value (RSD) obtained through sensing to the timing controller 11.

Hereinafter, the configuration of the source driver ICs (SDIC#1 to SDIC#k) according to the present invention will be described in more detail with reference to FIG. 3.

The first Example

3 is a diagram schematically showing the configuration of a source driver IC and a display panel according to a first embodiment of the present invention. Since each source driver IC (SDIC#1 to SDIC#k) has the same configuration, in FIG. 3, for convenience of description, any one of a plurality of source driver ICs (SDIC#1 to SDIC#k) is provided. ) Will be described only.

As illustrated in FIG. 3, the source driver IC (SDIC) includes a plurality of source signal input units 310, a sensing block 320, an analog-to-digital converter 400, and a sensing data calculation unit 410.

The plurality of source signal input units 310 are respectively connected to the data lines 14A to input a source signal Vdata_D or a sensing source signal Vdata_S to each pixel P through the data line 14A. . In one embodiment, the source signal input unit 310 is a shift register, a latch, a digital-to-analog converter, and to supply a source signal (Vdata_D) for image display or a source signal (Vdata_S) for sensing to each pixel (P), and It may include a configuration such as an output buffer.

The source signal input unit 310 receives the image data from the timing controller 11 when the normal mode is driven, and converts the received image data into a source signal (Vdata_D) for image display for image display according to the source control signal (SDC) To supply to each data line 14A. In addition, the source signal input unit 310 receives sensing data from the timing controller 11 when the sensing mode is driven, and receives the received sensing data as a sensing source signal (Vdata_S) for sensing according to the source control signal (SDC). It is converted and supplied to the data lines 14A.

In one embodiment, the sensing data may include valid sensing data for obtaining an effective sensing value from each pixel P and reference sensing data for obtaining a reference sensing value from each pixel P, , According to this embodiment, the source signal input unit 310 converts data for effective sensing into a valid sensing source signal during the sensing period and supplies the data lines 14A with reference sensing data, and the reference sensing data for reference sensing source It can be converted into a signal and supplied to the data lines 14A.

The sensing block 320 is connected to the sensing lines 14B through each sensing channel CH#1 to CH#n to sense pixels P connected to each sensing line 14B. Hereinafter, the configuration of the sensing block 320 according to the first embodiment of the present invention will be described in more detail with reference to FIG. 4.

4 is a block diagram schematically showing the configuration of a sensing block according to a first embodiment of the present invention. As shown in FIG. 4, the sensing block 320 according to the first embodiment of the present invention includes a plurality of sensing units SU#1 to SU#n as shown in FIG. 4.

The sensing units SU#1 to SU#n are connected to each sensing channel CH#1 to CH#n to acquire a sensing value by sensing the pixels P connected to the corresponding sensing channels CH1 to CHn. Specifically, the sensing units SU#1 to SU#n are effective sensing values and respective pixels obtained from the driving transistors of each pixel P according to the supply of a source signal for effective sensing to each pixel P in the sensing section. In accordance with the supply of the source signal for reference sensing to (P), a reference sensing value obtained from the driving transistor of each pixel P is obtained.

At this time, the sensing values obtained by the sensing units SU#1 to SU#n may include white noise, common noise, and offsets of the sensing unit sensing units SU#1 to SU#n. White noise appears as randomness whenever it is sensed by noise that exists in the natural state, and the value is converged to 0 as sensing is repeated. Common noise is noise generated in the driving environment, which occurs randomly, but unlike white noise, it affects all sensing units (SU#1~SU#n) in common and converges to an unknown value even if sensing is repeated. There are features. The offset is a characteristic generated by the process deviation of the sensing units (SU#1 to SU#n) and has a characteristic that adjacent sensing units (SU#1 to SU#n) have similar values.

As illustrated in FIGS. 5 and 6, the sensing units SU#1 to SU#n according to the first embodiment of the present invention remove common noise and offset included in an effective sensing value or a reference sensing value, When sensing once in the sensing section, an effective sensing value is obtained according to the application of the valid sensing source signal (Valid) from the Odd sensing channel, and the application of the reference sensing source signal (Reference) from the Even channel. Acquire the reference sensing value.

That is, when sensing once, the source signal input unit 310 applies a valid sensing source signal (Valid) to each pixel P connected to the odd sensing channel, and for reference sensing to each pixel P connected to the even sensing channel. When the source signal (Reference) is applied, the sensing units (SU#1 to SU#n) acquire an effective sensing value from an odd sensing channel connected to the pixel P to which the valid sensing source signal (Valid) is applied, and reference The reference sensing value is obtained from the even sensing channel connected to the pixel P to which the sensing source signal Reference is applied.

The sensing units SU#1 to SU#n transmit the effective sensing values obtained through the odd sensing channel and the reference sensing values obtained through the even sensing channel to the analog-to-digital converter 400.

Similarly, when sensing twice, the sensing units SU#1 to SU#n acquire reference sensing values according to the application of the source signal for reference sensing from the odd sensing channel in the sensing section, and even The effective sensing value according to the application of the valid sensing source signal (Valid) is obtained from the (Even) channel.

That is, when sensing twice, the source signal input unit 310 applies a reference sensing source signal (Reference) to each pixel P connected to the odd sensing channel, and is effective for sensing each pixel P connected to the even sensing channel. When the source signal (Valid) is applied, an effective sensing value is obtained through an even sensing channel connected to the pixel (P) to which the sensing unit (SU#1 to SU#n) effective source signal (Valid) is applied and referenced. The reference sensing value is acquired through the odd sensing channel connected to the pixel P to which the sensing source signal Reference is applied.

The sensing units SU#1 to SU#n transmit the reference sensing values obtained through the odd sensing channel and the effective sensing values obtained through the even sensing channel to the analog-to-digital converter 400.

In one embodiment, the sensing units SU#1 to SU#n determine the current value between the source and drain of the driving transistor included in each pixel P to which the corresponding sensing units SU#1 to SU#n are connected. It can be obtained as an effective sensing value or a reference sensing value. Hereinafter, a configuration of the sensing units SU#1 to SU#n for obtaining the current value between the source and drain of the driving transistor as a sensing value will be briefly described with reference to FIG. 7.

7 is a block diagram showing the configuration of a sensing unit of the current sensing method according to an embodiment of the present invention.

As shown in FIG. 7, the sensing unit SU according to an embodiment of the present invention includes a current integrator 710 and a sample and hold circuit 720.

The current integrator 710 integrates and outputs the pixel current from the sensing line 14B through the sensing channel CH. To this end, the current integrator 710 includes an amplifier (AMP), an integrating capacitor (Cfb), and a reset switch (RST).

The amplifier AMP includes an inverting input terminal (-) receiving the source-drain current Ids of the driving transistor DT, a non-inverting input terminal receiving a reference voltage Vref (+), and an integral value Vout. It includes an output terminal for outputting.

The integrating capacitor Cfb is connected between the inverting input terminal (-) of the amplifier AMP and the output terminal, and the reset switch RST is connected to both ends of the integrating capacitor Cfb.

Since the method for integrating the current Ids between the source and drain of the driving transistor and outputting the current integrator 710 as an integral value Vout is a known technique, a detailed description thereof will be omitted.

The sample and hold circuit 720 samples the integral value Vout output from the current integrator 710 through the sampling switch S1 and stores it in the sampling capacitor C, and stores the integral value stored in the sampling capacitor C. It is input to the analog-to-digital converter 400 shown in FIG. 4 through the holding switch S2.

In FIG. 7, it has been described that the sensing unit senses the characteristics of the driving transistor using the current sensing method. However, the sensing unit according to the present invention is not limited thereto, and may sense the characteristics of the driving transistor using the voltage sensing method. According to this embodiment, the current integrator 710 of the configuration of the sensing unit illustrated in FIG. 7 may be omitted.

Referring to FIG. 3 again, the analog digital converter (ADC, 400) converts the effective sensing value output from the sensing units (SU#1 to SU#n) into a digital value or converts the reference sensing value into a digital value. To convert. The analog-to-digital converter 400 provides an effective sensing value and a reference sensing value converted to digital values to the sensing data calculator 410.

The sensing data calculating unit 410 calculates a real sensing value (RSD) for each pixel (P) by using a digital value for the effective sensing value and a reference sensing value transmitted from the ADC 400. In one embodiment, the sensing data calculator 410 may calculate a real sensing value (RSD) for each pixel P by differentially calculating a digital value for an effective sensing value and a digital value for a reference sensing value. have.

Specifically, the sensing data calculator 410 differentially digitalizes the digital value of the effective sensing value obtained from the odd sensing channel and the digital value of the reference sensing value obtained from the even sensing channel at the time of sensing. The real sensing value (RSD) of P) is obtained.

In addition, the sensing data calculator 410 differentially compares the digital value of the reference sensing value obtained from the odd sensing channel and the digital value of the effective sensing value obtained from the even sensing channel during the second sensing, thereby realizing the pixels connected to the even sensing channel. Obtain a sensing value (RSD).

When the sensing data calculating unit 410 expresses a method of obtaining a real sensing value (RSD) for the S-th sensing channel by using a mathematical expression, it is expressed by Equation 1 or 2 below.

In Equations 1 and 2, RSD#S represents the real sensing value of the S-th sensing channel, and VSD#S is the effective sensing value obtained when an effective sensing source signal is applied to a pixel P connected to the S-th sensing channel. Denotes, DSD#S+1 denotes a reference sensing value obtained when a source signal for reference sensing is applied to a pixel P connected to the S+1 th sensing channel, and DSD#S-1 denotes S-1 th sensing The reference sensing value obtained when the reference sensing source signal is applied to the pixel P connected to the channel.

At this time, since the sensing value of the S-th sensing channel obtained by the S-th sensing unit (SU#S) may include white noise, common noise, and offset, VSD#S, DSD#S+1, and DSD#S -1 is expressed by Equations 3 to 5 below.

In Equations 3 to 5, VSD'#S represents the sensing value obtained by subtracting the common noise and offset from the effective sensing value of the S-th sensing channel, WN represents the white noise of the corresponding sensing unit, and CN represents the common noise. , OS indicates the offset of the corresponding sensing unit.

If Equations 1 and 2 are expressed again using Equations 3 to 5, they may be expressed as Equations 6 and 7 below.

At this time, since the offsets between the sensing units adjacent to each other OS#S and OS#(S+1) and OS#S and OS#(S-1) have similar values, Equations 6 and 7 are It can be expressed as Equations 8 and 9 below.

As can be seen from the above equations 8 and 9, it can be seen that common noise and offset are removed from the effective sensing values obtained in each sensing channel by differentially calculating sensing values obtained from adjacent sensing channels and even sensing channels. have.

In addition, the sensing block 320 according to the present invention may additionally remove white noise from the effective sensing value of each sensing channel by repeating the sensing process for the above-described odd sensing channel and even sensing channel multiple times.

Hereinafter, a method in which the sensing block 320 according to the present invention acquires a real sensing value RSD from the first sensing channel CH#1 and the second sensing channel CH#2 will be described as an example.

First, by applying the above equations 1 to 9 for the first sensing channel (CH#1) and the second sensing channel (CH#2), the real sensing value for the first sensing channel (CH#1) ( RSD#1) may be calculated as in Equation 10, and the real sensing value RSD#2 for the second sensing channel CH#1 may be calculated as in Equation 11.

At this time, if the above-described sensing process is repeated multiple times, white noise may also be removed.

In the above-described embodiment, the sensing data calculator 410 differentially determines the effective sensing value and the reference sensing value obtained by the corresponding sensing units (SU#1 to SU#n) for each sensing channel, and is connected to each sensing channel. It was described as calculating the real sensing value (RSD) of. However, in another embodiment, the sensing units SU#1 to SU#n transmit the effective sensing value and the reference sensing value to the timing controller 11, and the timing controller 11 determines the effective sensing value and the reference sensing value. By performing the differential operation on the real sensing value (RSD) of the pixel (P) connected to each sensing channel may be obtained.

In addition, in the above-described embodiment, after the ADC 400 converts the effective sensing value and the reference sensing value to digital values, the sensing data calculator 410 determines the digital values of the effective sensing values and the digital values of the reference sensing values. It was described as being differential. However, in another embodiment, the sensing data calculation unit 410 calculates a real sensing value by differentially calculating an effective sensing value and a reference sensing value, and the ADC 400 converts the real sensing value to a digital value to determine the timing controller ( 11).

Meanwhile, in the above-described first embodiment, when the sensing block 320 calculates the real sensing value (RSD), the effective sensing value and the reference sensing value obtained from two adjacent sensing channels are differentially calculated to cancel out common noise and offset. Explained. In the case of the first embodiment, the entire sensing is performed twice, but in the first sensing, it is possible to acquire only the real sensing value of the odd sensing channel, and in the second sensing, only the real sensing value of the even sensing channel is acquired. As a result, as a result, sensing becomes the same as that performed once, resulting in a sensing efficiency of 50%.

That is, when the time required for sensing once is T, 2T of time is required for one sensing block 320 to perform sensing on all n sensing channels. Therefore, in order to reduce the sensing time, since the reference sensing channel connected to the pixel to which the reference sensing source signal is applied and the sensing unit connected to the reference sensing channel must be additionally arranged for each sensing channel, the number of sensing channels and The number of sensing units is doubled, and the real sensing value is also doubled compared to a single operation.

Therefore, hereinafter, a configuration of a sensing block capable of reducing the number of sensing channels or sensing channels or having a higher sensing efficiency than the first embodiment while reducing the common noise and offset will be described.

2nd Example

The sensing block 30 according to the second embodiment has the same configuration as the sensing block 320 according to the first embodiment, but unlike the first embodiment, n sensing units SU#1 to SU#n are used. A sensing group is formed by grouping in m units, and sensing is performed for each sensing group. That is, in the second embodiment, the sensing block 320 performs sensing in a sensing group unit consisting of m sensing units SU#1 to SU#m.

In addition, in the first embodiment, it is assumed that the offsets of adjacent sensing units have similar values to each other, to calculate the real sensing value (RSD), but in the second embodiment, each of them is obtained to obtain a more accurate real sensing value (RSD). The offset is calculated directly for each sensing unit (SU#1 to SU#n).

Hereinafter, the operation of the sensing block according to the second embodiment will be described in detail with reference to FIGS. 8 and 9. 8 is a table showing a sensing method according to a second embodiment of the present invention, and FIG. 9 is a timing diagram showing a sensing method according to the second embodiment.

In FIGS. 8 and 9, for convenience of explanation, one sensing group SG is composed of eight sensing units, but this is only one example, and one sensing group SG is composed of nine or more sensing units or 2 It may be composed of dog to 7 sensing units. Also, for convenience of description, the second embodiment will be described based on eight sensing units SU#1 to SU#8 included in the first sensing group SG1.

The sensing units (SU#1 to SU#8) according to the second embodiment sense the offset of each sensing unit (SU#1 to SU#8) during the offset sensing section when operating in the sensing mode and during the effective sensing section Effective sensing is performed for each pixel P.

The sensing units SU#1 to SU#8 use the sensing values obtained from the corresponding pixel P when the source signal for offset sensing is applied to each pixel P during the offset sensing period. Calculate the offset of SU#1~SU#8). Specifically, the source signal input unit 310 applies a source signal for offset sensing to each pixel P during the offset sensing period, and each sensing unit SU#1 to SU#8 is connected to the corresponding pixel P Sensing values are acquired through sensing channels (CH#1 to CH#8). In this case, the source signal for offset sensing may be the same source signal as the source signal for reference sensing in the first embodiment.

In one embodiment, since the sensed value includes white noise, each of the sensing units SU#1 to SU#8 performs sensing using a source signal for offset sensing multiple times for each pixel P. By repeating, white noise can be reduced. According to this embodiment, the sensing units SU#1 to SU#8 calculate an average value of the averaged sensing values calculated for each sensing time as an offset of the corresponding sensing units SU#1 to SU#8. Can be.

As described above, in the second embodiment, during the offset sensing section, the sensing units SU#1 to SU#8 use the sensing values obtained when the source signal for offset sensing is applied to each pixel P. Since the offsets of the units SU#1 to SU#8 are directly calculated, it is possible to obtain a more accurate real sensing value than the first embodiment of offsetting offsets on the assumption that the offsets of adjacent sensing units are similar. .

On the other hand, any one of the eight sensing units (SU#1 to SU#8) included in the first sensing group SG1 in the effective sensing section receives a source signal for reference sensing from a pixel connected to the corresponding sensing unit. A reference sensing value when applied is acquired, and the remaining seven sensing units acquire an effective sensing value when an effective sensing source signal is applied from pixels connected to the corresponding sensing unit.

That is, during the effective sensing period, the source signal input unit 310 applies a source signal for effective sensing to pixels connected to seven sensing units (eg, SU#1 to SU#7), and one sensing unit (eg, SU#8) ) Applies a source signal for reference sensing to a pixel connected to. Accordingly, seven effective sensing values are obtained by seven sensing units (SU#1 to SU#7) connected to pixels to which the source signal for effective sensing is applied during the effective sensing period, and the pixel to which the source signal for reference sensing is applied. One reference sensing value is acquired by one sensing unit (SU#8) connected to.

In the second embodiment, each sensing unit (SU#1 to SU#8) repeats the above-described sensing process 8 times for each pixel, but the source signal input unit 310 is a source for reference sensing for each sensing difference. The pixel to which the signal is applied varies. That is, the source signal input unit 310 applies the reference sensing source signal to the pixel connected to the 8th sensing channel (CH#8) for one sensing and the pixel connected to the 7th sensing channel (CH#7) for 2 sensing. The reference sensing source signal is applied to the 3rd sensing channel, and the reference sensing source signal is applied to the pixel connected to the 6th sensing channel (CH#6) for 3 sensing times, and to the 5th sensing channel (CH#5) for 4 sensing times The source signal for reference sensing is applied to the connected pixel. In addition, the source signal input unit 310 applies a source signal for reference sensing to a pixel connected to the fourth sensing channel (CH#4) when sensing 5 times, and is connected to a third sensing channel (CH#3) when sensing 6 times. The source signal for reference sensing is applied to the pixel, and the source signal for reference sensing is applied to the pixel connected to the second sensing channel (CH#2) for seven sensing times, and the first sensing channel (CH#1) for eight sensing times. A source signal for reference sensing is applied to a pixel connected to. Accordingly, seven valid sensing and one reference sensing are performed for every sensing channel included in the first sensing group (SG1).

As described above, in the case of the second embodiment, sensing is performed 8 times while varying the pixel to which the source signal for reference sensing is applied for each sensing difference, and as a result of sensing 8 times, it is 7 for each sensing unit (SU#1 to SU#8). Since the effective sensing values of the dogs are obtained, it has a sensing efficiency of 87.5%, which can improve the sensing efficiency compared to the first embodiment.

In addition, in the second embodiment, since any one of the sensing units (SU#1 to SU#8) performing effective sensing performs reference sensing, a separate sensing channel and a sensing unit for reference sensing are not required. The size of the source driver IC and the display panel can be reduced, and the manufacturing cost of the display panel can also be reduced.

Meanwhile, the ADC 400 converts 7 effective sensing values obtained by 7 sensing units and 1 reference sensing value obtained by 1 sensing unit into digital values for each sensing difference, and generates a sensing data calculation unit ( 410).

The sensing data calculation unit 410 differentially calculates a digital value for each of the seven effective sensing values obtained by seven sensing units for each sensing session and a digit value for a reference sensing value obtained by one sensing unit. By doing so, real sensing values (RSDs) for pixels connected to the seven sensing units obtained effective sensing values are obtained.

If this is expressed as an equation, it is expressed as Equation 12 below.

In Equation 12, RSD#S means the real sensing value of the pixel connected to the Sth sensing channel (CH#S), and VSD#S is effective sensing to the pixel P connected to the Sth sensing channel (CH#S). Indicates the effective sensing value obtained when the source signal is applied, and OS#S means the average of the offsets acquired by the sensing unit (SU#6) connected to the Sth sensing channel through multiple offset sensing, DSD# R is a reference sensing value obtained when a signal for reference sensing is applied to a pixel P connected to the R-th sensing channel (CH#R), and OS#R is connected to the R-th sensing channel (CH#R) The sensing unit (SU#R) means the average of offsets obtained through multiple offset sensing.

At this time, since OS#S and OS#R include common noise, and OS#S and OS#R can be expressed as Equations 13 and 14, respectively, Equation 12 is for VSD#S. Using Equation 3 and Equations 13 and 14 below, it can be expressed again as Equation 15 below.

At this time, CN' is an average value of common noise generated during offset sensing, and Equation 15 may be expressed again as Equation 17 below.

As described above, the sensing units SU#1 to SU#8 according to the second embodiment may include first to eighth sensing units SU# as the pixels to which the source signal for reference sensing is applied vary for each sensing cycle. 1 to SU#8), 7 effective sensing values and 1 reference sensing value are obtained by performing 7 effective sensing and 1 reference sensing for each pixel connected. In addition, the sensing data calculating unit 410 differentially detects an effective sensing value and a reference sensing value for each sensing unit (SU#1 to SU#8) to a pixel connected to each sensing unit (SU#1 to SU#8). For each of the sensing units (SU#1 to SU#8), the 7 real sensing values (RSD) obtained for each sensing unit (SU#1 to SU#8) are averaged, and the corresponding sensing units (SU#1 to SU#) 8) Calculate the final real sensing value of the connected pixel.

Hereinafter, a method in which the sensing block 320 according to the present invention performs effective sensing on pixels connected to the first and second sensing channels CH#1 and CH#2 included in the first sensing group SG1. Examples will be described with reference to Table 1 and Table 2 below and FIGS. 8 and 9. Table 1 shows a method of calculating a real sensing value of a pixel connected to the first sensing channel (CH#1), and Table 2 is a method of calculating a real sensing value of a pixel connected to the second sensing channel (CH#2). It shows.

When the pixels to which the reference source signal is applied are varied for each sensing difference in the order as shown in FIGS. 8 and 9, the first sensing connected to the first sensing channel (CH#1) as shown in Table 1 The unit SU#1 senses pixels connected to the first sensing channel CH#1 to acquire seven effective sensing values VSD. In addition, the sensing units SU#2 to SU#8 connected to the second to eighth sensing channels CH#2 to CH#8 are connected to the corresponding sensing channels CH#2 to CH#8 for each sensing session. Each reference sensing value DSD is obtained based on a reference sensing signal applied to a connected pixel. Thereafter, the sensing data calculation unit 410 differentially calculates the effective sensing value VSD and the reference sensing value DSD for each sensing session, and averages the results of the differential calculation to the first sensing channel CH#1. The real sensing value (RSD) of the connected pixel is calculated.

Similarly, when the pixels to which the reference source signal is applied are varied for each sensing difference in the order as shown in FIGS. 8 and 9, as shown in Table 2, the second sensing channel (CH#2) The connected second sensing unit SU#2 senses pixels connected to the second sensing channel CH#2 to acquire seven effective sensing values VSD. In addition, the sensing units SU#1, SU#3 to SU#8 connected to the first sensing channel CH#1 and the third to eighth sensing channels CH#3 to CH#8 are each sensed. Each reference sensing value DSD is obtained based on a reference sensing signal applied to a pixel connected to a corresponding sensing channel. Thereafter, the sensing data calculating unit 410 differentially calculates the effective sensing value VSD and the reference sensing value DSD for each sensing session, and averages the results of the differential calculation to the second sensing channel CH#2. The real sensing value (RSD) of the connected pixel is calculated.

As described above, according to the second embodiment, since the offsets of the respective sensing units SU#1 to SU#8 are calculated directly, a more accurate real sensing value can be obtained than in the first embodiment, and eight sensing is sensed during effective sensing. Since 7 effective sensing values are obtained for each sensing unit (SU#1 to SU#8) by performing, it has a sensing efficiency of 87.5%, which can improve the sensing efficiency compared to the first embodiment. In addition, since a separate sensing channel and a sensing unit for reference sensing are not required, it is possible to reduce the size of the source driver IC and the display panel as well as the manufacturing cost of the display panel.

Third Example

10 is a diagram showing a configuration of a sensing block according to a third embodiment of the present invention, and FIG. 11 is a timing diagram showing a sensing method according to a third embodiment of the present invention.

In the case of the sensing block 320 illustrated in FIG. 10, unlike the sensing block 320 illustrated in FIG. 4, n/2 muxes (MUX, 1000) having an input and an output of 2:1 are additionally included. That the number of the sensing unit (SU) (n/2) due to the mux 1000 is reduced in half compared to the number (n) of the sensing unit (SU) according to the first and second embodiments Able to know. Accordingly, in the third embodiment, the size of the source driver IC and the size of the display panel can be further reduced, and the amount of data transmitted from the sensing block 320 to the timing controller 11 can also be reduced.

At this time, the sensing block 320 groups m sensing units (SU#1 to SU#m) into one sensing group (SG), and performs sensing for each sensing group (SG). Since the sensing block 320 according to the third embodiment is a structure in which two sensing channels adjacent to each other are connected to one sensing unit through the MUX 1000, m sensing units included in one sensing group (SG) ( SU#1 to SU#m) sense pixels connected to 2m sensing channels (CH#1 to CH#2m).

According to the above-described embodiment, the MUX 1000 m m sensing channels among the 2 m sensing channels (CH#1 to CH#2m) included in one sensing group (SG) m sensing units (SU #1 to SU#m), and m sensing units SU#1 to SU#m perform sensing on m odd sensing channels in the same manner as in the second embodiment.

When sensing for the odd sensing channel is completed, the MUX 1000 is configured to detect the remaining m even sensing channels among the 2 m sensing channels (CH#1 to CH#2m) included in the sensing group (SG) m sensing units ( SU#1 to SU#m), and m sensing units (SU#1 to SU#m) perform sensing on m even sensing channels in the same manner as in the second embodiment, resulting in a total of 2m Sensing for the sensing channel is completed.

Hereinafter, the operation of the sensing block according to the third embodiment will be described in more detail with reference to FIGS. 10 and 11. 10 and 11, for convenience of explanation, one sensing group is composed of eight sensing units (SU#1 to SU#8), and eight sensing units (SU#1 to SU#8) are 16 sensing channels ( CH#1 to CH#16) are illustrated as sensing pixels connected to each other, but this is only an example, and one sensing group SG is composed of 9 or more sensing units or 2 to 7 sensing units. Alternatively, 8 sensing units may sense pixels connected to 16 or more sensing channels (eg, 24 sensing channels).

The sensing units (SU#1 to SU#8) according to the third embodiment sense the offset of each sensing unit (SU#1 to SU#8) during the offset sensing section when operating in the sensing mode and each during the effective sensing section. Effective sensing is performed on the pixel P.

Specifically, when the MUX 1000 connects m odd sensing channels to m sensing units SU#1 to SU#8, m sensing units connected to the odd sensing channel (SU#1 to SU#8) ) Is the offset value of the m sensing units (SU#1 to SU#8) connected to the odd sensing channel using the sensing value obtained from the pixel when the offset sensing source signal is applied to each pixel during the offset sensing period. Calculate. In addition, when the MUX 1000 connects m even sensing channels to m sensing units (SU#1 to SU#8), m sensing units (SU#1 to SU#8) connected to the even sensing channel are When the source signal for offset sensing is applied to each pixel during the offset sensing period, the offset of m sensing units SU#1 to SU#8 connected to the even sensing channel is calculated using the sensing value obtained from the pixel. .

At this time, similar to the second embodiment, m sensing units (SU#1 to SU#8) are included in the sensing values obtained by m of sensing units (SU#1 to SU#8), so white noise is included. ) May reduce white noise by repeating sensing using a source signal for offset sensing multiple times for each pixel. According to this embodiment, the m sensing units SU#1 to SU#8 may calculate an average value of sensing values calculated for each sensing time as an offset of the corresponding sensing unit.

In the above-described embodiment, it has been described that the offset of the m sensing units SU#1 to SU#8 is divided into an odd sensing channel and an even sensing channel. However, in the modified embodiment, since the offset of the sensing unit can be constant regardless of whether the sensing channel connected to the sensing unit is an odd sensing channel or an even sensing channel, m sensing units (SU#1 to SU#8) May calculate the offset based on when either one of the odd sensing channel or the even sensing channel is connected.

On the other hand, when the MUX 1000 connects m odd sensing channels to eight sensing units (SU#1 to SU#8) in the effective sensing section, eight sensing units connected to the odd sensing channel (SU#1 to SU) Any one of #8) acquires a reference sensing value when a reference sensing source signal is applied from a pixel connected to the sensing unit. In addition, the remaining seven sensing units acquire an effective sensing value when a valid sensing source signal is applied from a pixel connected to the sensing unit. At this time, in the same manner as in the second embodiment, the four sensing units SU#1 to SU#8 are repeated 8 times for each pixel, but the source signal input unit 310 performs each sensing. The reference sensing source signal is applied while varying the pixel to which the reference sensing source signal is applied for each turn.

Thereafter, when the MUX 1000 connects m even sensing channels to 8 sensing units (SU#1 to SU#8), of the 8 sensing units (SU#1 to SU#8) connected to the even sensing channel, Any one sensing unit obtains a reference sensing value when a source signal for reference sensing is applied from a pixel connected to the sensing unit. In addition, the remaining seven sensing units acquire an effective sensing value when a valid sensing source signal is applied from a pixel connected to the sensing unit. At this time, in the same way as in the second embodiment, the eight sensing units SU#1 to SU#8 are repeatedly performed eight times for each pixel, but the source signal input unit 310 The reference sensing source signal is applied while varying the pixel to which the reference sensing source signal is applied for each sensing difference.

ADC 400, when the odd sensing channel is connected to the sensing units (SU#1 ~ SU#8) by the MUX 1000, and the seven effective sensing values obtained by the seven sensing units for each sensing cycle Each reference sensing value obtained by one sensing unit is converted to a digital value and provided to the sensing data calculator 410.

In addition, the ADC 400, when the even sensing channel is connected to the sensing units (SU#1 ~ SU#8) by the MUX 1000, 7 effective sensing acquired by 7 sensing units for each sensing session. The value and one reference sensing value obtained by one sensing unit are respectively converted into digital values and provided to the sensing data calculator 410.

The sensing data calculation unit 410 is configured for digital values for each of the seven effective sensing values obtained by seven sensing units for each sensing difference for the odd sensing channels and for reference sensing values obtained by one sensing unit. Differential computation of the digit values and averaging of the results of the differential operations yields real sensing values for pixels connected to the odd sensing channel.

In addition, the sensing data calculation unit 410 digital values for each of the seven effective sensing values obtained by the seven sensing units for each sensing session for the even sensing channels and the reference sensing value obtained by one sensing unit By differentially computing the digit value for and averaging the results of the differential operation, real sensing values for pixels connected to the even sensing channel are obtained.

As described above, in the third embodiment, the sensing block 320 includes a plurality of muxes 1000 with input and output of 2:1, thereby reducing the number of sensing units in half compared to the first and second embodiments. It becomes possible.

In FIG. 10, a plurality of mux 1000 is illustrated as being included in the sensing block 320. However, in another embodiment, as shown in FIG. 12, a plurality of MUX 1000 is disposed outside the sensing block 320 and connects two sensing lines 14B adjacent to each other to one sensing channel CH. It may be possible. In one embodiment, a plurality of mux 1000 may be formed on the display panel.

4th Example

13 is a diagram schematically showing the configuration of a source driver IC and a display panel according to a fourth embodiment of the present invention. 13, in the case of the fourth embodiment, unlike the first to third embodiments, the display panel 10 includes a plurality of dummy pixels D and one dummy data line 14C connected to the plurality of dummy pixels. , And one dummy sensing line 14D connected to the plurality of dummy pixels D. In addition, the source driver IC (SDIC) includes one dummy sensing channel (CH#D) connected to one dummy sensing line 14D and one dummy sensing unit (SU#D) connected to a dummy sensing channel (CH#D). ).

First, each sensing unit (SU#1~SU#n) performs offset sensing on pixels connected to n sensing channels (CH#1~CH#n) during the offset sensing section, thereby performing each sensing unit (SU#1~ The offset of SU#n) is calculated, and the dummy sensing unit SU#D performs offset sensing on the dummy pixels connected to one dummy sensing channel CH#D, thereby offsetting the dummy sensing unit SU#D. Calculate The offset calculation method is the same as that described in the second embodiment, so a detailed description is omitted.

Then, during the effective sensing period, each sensing unit SU#1 to SU#n is effective sensing when a source signal for effective sensing is supplied from pixels connected to n sensing channels CH#1 to CH#n. The value is acquired, and the dummy sensing unit SU#D acquires a dummy sensing value when a dummy source signal is supplied from the dummy pixel D connected to one dummy sensing channel 14D.

The ADC 400 converts the effective sensing value obtained for each sensing unit (SU#1 to SU#n) and the dummy sensing value obtained by the dummy sensing unit (SU#D) into digital values, and the sensing data calculation unit ( 410) is a pixel connected to each sensing unit (SU#1 ~ SU#n) by differentially calculating the digital value of the effective sensing value and the dummy sensing value obtained for each sensing unit (SU#1 ~ SU#n) The real sensing values of (P) are calculated.

In the above-described embodiment, it has been described that sensing is performed once for n sensing channels CH#1 to CH#n, but in the modified embodiment, each sensing unit SU#1 to SU#n Similar to the second embodiment, m sensing units SU#1 to SU#m are grouped into one sensing group, and m sensing units SU#1 to SU#m included in one sensing group. ) May perform sensing m times for each sensing channel. Hereinafter, this content will be described in detail with reference to FIG. 14.

14 is a diagram showing a timing diagram of a sensing method according to a modified embodiment of the fourth embodiment. In FIG. 14, one sensing group (SG) is shown to be composed of eight sensing channels (CH#1 to CH#8), but this is only one example, and one sensing group is composed of 9 or more sensing channels or 2 It may be composed of more than 7 or less sensing channels.

First, the eight sensing units (SU#1 to SU#8) included in one sensing group perform offset sensing on pixels connected to the corresponding sensing units (SU#1 to SU#8) during the offset sensing section. The offset of the sensing units SU#1 to SU#8 is calculated, and the dummy sensing unit SU#D performs offset sensing on the dummy pixels connected to one dummy sensing channel CH#D, thereby dummy sensing unit Calculate the offset of (SU#D). The offset calculation method is the same as that described in the second embodiment, so a detailed description is omitted.

Eight sensing units (SU#1 to SU#8) included in one sensing group during an effective sensing period are applied when a source signal for effective sensing is applied from a pixel to which the corresponding sensing units (SU#1 to SU#8) are connected. The effective sensing value of is obtained, and the dummy sensing unit SU#D acquires a dummy sensing value when a dummy source signal is applied from a dummy pixel to which the dummy sensing unit SU#D is connected. In this case, the dummy source signal may be the same signal as the reference sensing source signal in the above-described embodiment.

Thereafter, the ADC 400 converts the effective sensing value obtained by each of the eight sensing units (SU#1 to SU#8) and the dummy sensing value acquired by the dummy sensing unit (SU#D) into digital values, and sensing. The data calculator 410 differentially calculates the digital value of the effective sensing value and the digital value of the dummy sensing value to obtain real sensing values for each of the eight sensing units SU#1 to SU#8. At this time, as described above, since each sensing unit (SU#1 to SU#8) performs sensing 8 times, since 8 real sensing values are calculated for each sensing unit (SU#1 to SU#8), sensing is performed. The data calculation unit 410 calculates the final real sensing values of each sensing unit SU#1 to SU#8 by averaging the eight real sensing values.

As described above, when the dummy sensing channel 14D and the dull sensing unit SU#D are added according to the fourth embodiment, since m sensing makes it possible to acquire real sensing values for all m channels, sensing efficiency is improved. It can be increased to 100%.

In another embodiment, the sensing block 320 includes one dummy sensing channel 14D and a dummy sensing unit SU#D and at the same time, any of two sensing channels adjacent to each other similar to the third embodiment. A plurality of muxes (not shown) connecting one to one sensing unit may be further included.

According to this embodiment, when sensing once, the sensing channels included in one sensing group are connected to each sensing unit (SU#1 to SU#8) through the mux, thereby sensing each sensing unit (SU#1 to SU#). 8) The pixels connected to the odd sensing channel are sensed to obtain an effective sensing value, and at the same time, one dummy sensing unit (SU#D) senses the pixel connected to the dummy sensing channel (CH#D) to obtain the dummy sensing value. To acquire.

Similarly, during the second sensing, even sensing channels included in one sensing group are connected to each sensing unit (SU#1 to SU#8) through MUX, so that each sensing unit (SU#1 to SU#8) is connected. The pixels connected to the even sensing channel are sensed to obtain an effective sensing value, and at the same time, one dummy sensing unit SU#D senses the pixel connected to the dummy sensing channel 14D to obtain a dummy sensing value.

According to this embodiment, since sensing of the pixels connected to the eight odd sensing channels is possible in one sensing, the sensing efficiency can be improved compared to the third embodiment in which sensing of seven odd sensing channels is possible in one sensing. , The number of physical sensing units can also be reduced compared to the case where n dummy sensing units are required for n sensing channels.

Those skilled in the art to which the present invention pertains will appreciate that the above-described present invention can be implemented in other specific forms without changing its technical spirit or essential features.

For example, in the above-described embodiment, although the sensing block is illustrated as being included in the source driver IC, this is only one example, and the sensing block may be implemented in a configuration physically separated from the source driver IC.

Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the following claims rather than the above detailed description, and it should be interpreted that all changes or modifications derived from the meaning and scope of the claims and equivalent concepts are included in the scope of the present invention. do.

10: display panel 11: timing controller
12: source driving circuit 13: gate driving circuit
14A: Data line 14B: Sensing line
15: gate line 310: source signal input
320: sensing block 330: analog to digital converter
340: sensing data calculation unit

Claims (20)

One reference sensing channel connected to pixels through m (m is an integer greater than or equal to 2) sensing channels, and sensing the pixel m times during an effective sensing period, and connected to a pixel to which a source signal for reference sensing is applied for each sensing difference A sensing block for acquiring a reference sensing value through and obtaining an effective sensing value through m-1 effective sensing channels connected to a pixel to which a source signal for effective sensing is applied; And
And a sensing data calculator for calculating a real sensing value for each sensing channel by using a difference between an effective sensing value obtained through the effective sensing channel and a reference sensing value obtained through the reference sensing channel for each sensing session,
A source drive IC for sensing characteristics of a driving transistor, wherein the pixels to which the reference sensing source signal is applied vary for each sensing difference. According to claim 1,
The sensing data calculator calculates the real sensing value for each sensing channel by averaging the differential value between the effective sensing value obtained through the effective sensing channel and the reference sensing value obtained through the reference sensing channel for each sensing session. Source drive IC for sensing the characteristics of the driving transistor, characterized in that. According to claim 1,
The sensing block acquires an offset according to application of an offset sensing source signal for each sensing channel during an offset sensing period before the effective sensing period,
The sensing data calculator acquires a first result value obtained by subtracting an offset obtained through a corresponding effective sensing channel from an effective sensing value obtained through each effective sensing channel for each sensing session and a reference sensing channel for each sensing session. For sensing characteristics of the driving transistor, the differential sensing value obtained by subtracting the offset obtained through the reference sensing channel from the reference sensing value is averaged to calculate the real sensing value for each sensing channel. Source drive IC. According to claim 3,
The sensing block corrects the offset by reducing white noise in the offset of each sensing channel,
The sensing data calculating unit calculates a real sensing value of each sensing channel by using a corrected offset. The source drive IC for sensing characteristics of the driving transistor. The method of claim 4,
The sensing block is a source for characteristic sensing of a driving transistor, characterized in that by reducing the white noise from the offset by averaging a plurality of offsets obtained by sensing each pixel a plurality of times for each sensing channel during the offset sensing period. Drive IC. According to claim 1,
A source that supplies the source signal for effective sensing to pixels connected to the m-1 effective sensing channels during the effective sensing period, and a source for supplying the source signal for reference sensing to pixels connected to the one reference sensing channel. Further comprising a signal input,
The source signal input unit is a source drive IC for sensing the characteristics of the driving transistor, characterized in that the variable to be applied to the source signal for the reference sensing for each sensing difference. According to claim 1,
The reference sensing source signal is a signal having a voltage level corresponding to a black gradation, and the effective sensing source signal is a signal having a voltage level corresponding to a gradation higher than the black gradation. Source drive IC for. According to claim 1,
The effective sensing value is obtained by using the current value between the source and drain of the driving transistor included in the corresponding pixel when the effective sensing source signal is supplied to the pixels connected to the effective sensing channel,
When the reference sensing source signal is supplied to the pixel connected to the reference sensing channel, the reference sensing value is obtained by using the current value between the source and drain of the driving transistor included in the pixel. Source drive IC for characteristic sensing. According to claim 1,
An analog digital converter (ADC) further converts the effective sensing value obtained from the effective sensing channel and the reference sensing value obtained from the reference sensing channel into digital values for each sensing session,
The sensing data calculator calculates a real sensing value of each sensing channel by differentially calculating a digital value of the effective sensing value and a digital value of the reference sensing value output from the analog-to-digital converter. Source drive IC for sensing the characteristics of the device. According to claim 1,
The sensing block is connected to the m sensing channels 1:1 and includes m sensing units for obtaining the reference sensing value or the effective sensing value from pixels connected to each sensing channel. Source drive IC for characteristic sensing. The method of claim 10,
The sensing unit,
During the effective sensing period, the current value between the source-drain of the driving transistor included in the pixels connected to the effective sensing channel or the current value between the source-drain of the driving transistor included in the pixels connected to the reference sensing channel is accumulated. An integrator generating an output value; And
And a sample and hold circuit connected to the output terminal of the integrator to sample the output value and output the effective sensing value or the reference sensing value. The method of claim 10,
The m sensing units form one sensing group,
The sensing block includes a plurality of sensing groups, a source drive IC for sensing characteristics of a driving transistor. A plurality of muxes selecting one of an odd sensing channel and an even sensing channel adjacent to each other in 2m sensing channels;
During an effective sensing period, m sensing channels connected through the plurality of mUXs are sensed m times, and a reference sensing value is acquired and valid through one reference sensing channel connected to a pixel to which a source signal for reference sensing is applied for each sensing difference. A sensing block for obtaining an effective sensing value through m-1 effective sensing channels connected to a pixel to which a sensing source signal is applied; And
And a sensing data calculator for calculating a real sensing value for each sensing channel by using a difference between an effective sensing value obtained through the effective sensing channel and a reference sensing value obtained through the reference sensing channel for each sensing session,
A source drive IC for sensing characteristics of a driving transistor, wherein the pixels to which the reference sensing source signal is applied vary for each sensing difference. The method of claim 13,
The plurality of MUXs connect m odd sensing channels to the sensing block during the first sensing period during the effective sensing period, and m even sensing channels to the sensing block during the second sensing period,
The sensing block senses the m odd sensing channels m times during the first sensing period to obtain a reference sensing value from one reference sensing channel among m odd sensing channels, and effective sensing from m-1 effective sensing channels. Acquiring a value, sensing the m even sensing channels m times during the second sensing period, obtaining a reference sensing value from one reference sensing channel among m even sensing channels and valid from m-1 effective sensing channels Acquire the sensing value,
The sensing data calculating unit calculates real sensing values for the m odd sensing channels during a first sensing period, and calculates real sensing values for m even sensing channels during a second sensing period. Source drive IC for sensing transistor characteristics. The method of claim 13,
The sensing block acquires an offset according to the application of the source signal for offset sensing from the odd sensing channel and the even sensing channel during the offset sensing interval before the effective sensing interval,
The sensing data calculation unit is a first result value obtained by subtracting an offset obtained through a corresponding effective sensing channel from an effective sensing value obtained from each effective sensing channel for each sensing session and a reference obtained from a reference sensing channel for each sensing session. A source drive IC for sensing characteristics of a driving transistor, characterized in that the real sensing value is calculated for each sensing channel by averaging a differential value between second sensing values obtained by subtracting an offset obtained through a corresponding reference channel from a sensing value. . The method of claim 15,
The sensing block corrects the offset by averaging the plurality of offsets obtained for each sensing channel by sensing the pixels multiple times through each sensing channel during the offset sensing period.
The sensing data calculating unit calculates a real sensing value of each sensing channel by using a corrected offset. The source drive IC for sensing characteristics of the driving transistor. The method of claim 13,
During the first sensing period, the source signal for effective sensing is supplied to pixels connected to m-1 effective sensing channels among the m odd sensing channels, and the reference sensing is applied to pixels connected to one reference sensing channel. A source signal is supplied, and the source signal for effective sensing is supplied to pixels connected to m-1 effective sensing channels among the m even sensing channels during the second sensing period, and connected to one reference sensing channel. Further comprising a source signal input for supplying the source signal for the reference sensing to the pixel,
The source signal input unit is a source drive IC for sensing characteristics of a driving transistor, characterized in that a pixel to which the source signal for the reference sensing is applied varies for each sensing difference during the first and second sensing sections. The method of claim 13,
The reference sensing source signal is a signal having a voltage level corresponding to a black gradation, and the effective sensing source signal is a signal having a voltage level corresponding to a gradation higher than the black gradation. Source drive IC for. The method of claim 13,
Further comprising an analog-to-digital converter for converting the effective sensing value and the reference sensing value obtained for each sensing difference for each sensing channel to a digital value,
The sensing data calculating unit calculates a real sensing value of each sensing channel by using a differential result of the digital value of the effective sensing value and the digital value of the reference sensing value output from the analog-to-digital converter. Source drive IC for sensing characteristics of driving transistors. The method of claim 13,
The sensing block is selectively connected to one of the adjacent sensing channel and the even sensing channel to obtain the reference sensing value or the effective sensing value from the odd sensing channel when the odd sensing channel is connected, and when the even sensing channel is connected, A source drive IC for sensing characteristics of a driving transistor, comprising m sensing units acquiring the reference sensing value or the effective sensing value from an even sensing channel.

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