KR102681576B1 - Source Driver IC for Sensing Characteristic of Driving Transistor - Google Patents

Abstract

The source drive IC for sensing the characteristics of the driving transistor according to one aspect of the present invention, which can eliminate noise generated when sensing the electrical characteristics of the driving transistor, is connected to the pixels through m (m is an integer of 2 or more) sensing channels. During the effective sensing period, the pixel is sensed m times, and the reference sensing value is obtained through one reference sensing channel connected to the pixel to which the reference sensing source signal is applied for each sensing session. The pixel to which the effective sensing source signal is applied is A sensing block that obtains effective sensing values through m-1 effective sensing channels connected to; And a sensing data calculation unit that calculates a real sensing value for each sensing channel using the difference between an effective sensing value obtained through the effective sensing channel for each sensing session and a reference sensing value obtained through the reference sensing channel. , the pixel to which the source signal for reference sensing is applied is characterized in that it varies for each sensing session.

Description

Source Driver IC for Sensing Characteristics of Driving Transistor}

This specification relates to a display device, and more specifically, to a source drive IC that can sense the 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 on its own, and has the advantages of fast response speed, high luminous efficiency, brightness, and viewing angle.

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

An organic light emitting display device arranges pixels, each including OLED, in a matrix form and adjusts the luminance of the pixels according to the gradation of video data. Each pixel includes a driving transistor (Driving TFT: Thin Film Transistor) that controls the driving current flowing through the OLED according to the 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 over driving time, resulting in differences for each pixel. If the electrical characteristics of the driving transistor vary for each pixel, the luminance between pixels for the same video data varies, making it difficult to realize the desired image.

Among the methods for compensating for deviations in the electrical characteristics of driving transistors, the external compensation method measures sensing values corresponding to the electrical characteristics of the driving transistors through a sensing unit and modulates video data input from the outside using these sensing values. Compensates for variations in electrical characteristics of transistors.

In the case of this external compensation method, the exact value cannot be sensed because the sensing value sensed by the sensing unit includes white noise, common noise generated from the chip operation and environment, and the offset of the sensing unit, and this causes errors on the display. There is a problem that a dim phenomenon may occur.

The present invention is intended to solve the above-mentioned problems, and its technical task is to provide a source drive IC for sensing the characteristics of a driving transistor that can eliminate noise generated when sensing the electrical characteristics of the driving transistor.

In addition, another technical task of the present invention is to provide a source drive IC for sensing the characteristics of a driving transistor that can improve sensing efficiency.

In addition, another technical task of the present invention is to provide a source drive IC for sensing the characteristics of a driving transistor that can reduce the number of sensing units or sensing channels for sensing the electrical characteristics of the driving transistor.

A source drive IC for sensing the characteristics of a driving transistor according to an aspect of the present invention to achieve the above-described object is connected to pixels through m (m is an integer of 2 or more) sensing channels, and the pixels are connected during the effective sensing period. is sensed m times, and for each sensing round, the reference sensing value is obtained through one reference sensing channel connected to the pixel to which the reference sensing source signal is applied, and m-1 effective sensing values are connected to the pixel to which the effective sensing source signal is applied. A sensing block that obtains effective sensing values through a channel; And a sensing data calculation unit that calculates a real sensing value for each sensing channel using the difference between an effective sensing value obtained through the effective sensing channel for each sensing session and a reference sensing value obtained through the reference sensing channel. , the pixel to which the source signal for reference sensing is applied is characterized in that it varies for each sensing session.

A source drive IC for sensing the characteristics of a driving transistor according to an aspect of the present invention to achieve the above-described object uses one of an odd sensing channel and an even sensing channel adjacent to each other in 2m sensing channels. A plurality of muxes (MUX) to select; During the effective sensing period, the m sensing channels connected through the plurality of muxes are sensed m times, and a reference sensing value is obtained through one reference sensing channel connected to the pixel to which the reference sensing source signal is applied for each sensing session, and the effective sensing value is obtained. A sensing block that obtains an effective sensing value through m-1 effective sensing channels connected to pixels to which a sensing source signal is applied; And a sensing data calculation unit that calculates a real sensing value for each sensing channel using the difference between an effective sensing value obtained through the effective sensing channel for each sensing session and a reference sensing value obtained through the reference sensing channel. , the pixel to which the source signal for reference sensing is applied is characterized in that it varies for each sensing session.

According to the present invention, the electrical characteristics of the driving transistor can be accurately sensed by removing white noise, common noise, or offset generated when sensing the electrical characteristics of the driving transistor, and through this, the deviation in the electrical characteristics of the driving transistor can be accurately compensated. This has the effect of preventing the occurrence of dimming phenomenon.

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

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, which not only reduces the size of the display device but also reduces the amount of data transmitted to the timing controller. It works.

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

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

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. The present embodiments only serve to ensure that the disclosure of the present invention is complete and that common knowledge in the technical field to which the present invention pertains is not limited. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are illustrative, and the present invention is not limited to the matters shown. Like reference numerals refer to like elements throughout the specification. Additionally, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

When 'includes', 'has', 'consists of', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise.

When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description.

In the case of a description of a temporal relationship, for example, if a temporal relationship is described as 'after', 'successfully after', 'after', 'before', etc., 'immediately' or 'directly' Unless used, non-consecutive cases may also be included.

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

The term “at least one” should be understood to include all possible combinations from one or more related items. For example, “at least one of the first, second, and third items” means each of the first, second, or third items, as well as two of the first, second, and third items. It can mean a combination of all items that can be presented from more than one.

Each feature of the various embodiments of the present invention can be combined or combined with each other partially or entirely, and various technical interconnections and operations are possible, and each embodiment can be implemented independently of each other or together in a related relationship. It may be possible.

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

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

Referring to FIG. 1, a display device 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. A plurality of data lines 14A and a plurality of sensing lines 14B may be formed to intersect the plurality of gate lines 15.

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

Pixel P is connected to 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 the gate pulse input through the gate line 15, and the driving transistor included in each pixel P through the sensing line 14B ( Characteristic information (not shown) is output. In one embodiment, the characteristic information of the driving transistor may include the threshold voltage or mobility of the driving transistor.

The pixel P receives 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 shown 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 has 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 an input terminal of a low potential driving voltage (EVSS), and an organic compound layer located between the anode electrode and the cathode electrode.

The pixel structure shown in FIG. 2 is only an example to help understand the present invention, and the pixel structure can be modified in various ways, so the technical idea of the present invention is not limited to this embodiment.

Referring again to FIG. 1, the timing controller 11 controls the operations of the source driving circuit 12 and the gate driving circuit 12. Specifically, the timing controller 11 operates a source driving circuit ( 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 operates a source driving circuit so that each pixel (P) can be driven in a normal mode for displaying image data and a sensing mode in which a sensing value is obtained by sensing characteristic information of a driving transistor. 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 the power-on process before driving in the normal mode or during the power-off process after the normal mode. In another embodiment, the sensing mode may be performed in vertical blank periods during normal mode driving.

The timing controller 11 provides 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 normal mode and sensing mode. Based on this, normal mode and sensing mode can be distinguished, and source control signal (SDC) and gate control signal (GDC) can be generated for each mode.

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

In one embodiment, the sensing data may include effective sensing data 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 that can suppress the generation of pixel current when a source signal corresponding to the reference sensing data is input to each pixel. As an example, data for reference sensing may be image data corresponding to a black gradation.

Meanwhile, the timing controller 11 derives a compensation value to compensate for changes in the electrical characteristics of the driving transistor included in each pixel (P) based on the sensing value acquired in the sensing mode, and operates the source driving circuit based on the compensation value. Modify the video data to be provided with (12).

Specifically, the timing controller 11 applies the real sensing value (RDS) transmitted from the source driving circuit 12 when driving in the sensing mode to a pre-stored compensation algorithm to determine the threshold voltage deviation and movement of the driving transistor included in each pixel. After deriving the amount of change, a compensation value that can compensate for the amount of change is derived. This compensation value may be stored in a memory (not shown), and each time 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 the gate control signal (GDC) when driving in normal mode, and then drives the generated first type gate pulse to each gate line 15. supplied sequentially.

When driving in the sensing mode, the gate driving circuit 13 generates a second type gate pulse for sensing each pixel (P) based on the gate control signal (GDC), and then drives the generated second type gate pulse to each gate line. It is supplied sequentially to fields 15.

In one embodiment, the on pulse section of the second type gate pulse may be wider than that of the first type gate pulse. The on pulse section of the second type gate pulse corresponds to 1 line sensing on time, where 1 line sensing on time refers to the time for simultaneously sensing pixels (P) included in 1 horizontal line (L#1 to L#p). This refers to the scan time required for

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

When operating in 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 lines the corresponding data line. Supply to (14A).

When operating in sensing mode, the source driver IC (SDIC#1 to SDIC#k) converts the sensing data supplied from the timing controller 11 to each pixel (P) into a sensing source signal (Vdata_S), and 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~SDIC#k) transmits the real sensed value (RSD) obtained through sensing to the timing controller (11).

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

1st Example

Figure 3 is a diagram schematically showing the configuration of a source driver IC and a display panel according to the first embodiment of the present invention. Since the configuration of each source driver IC (SDIC#1 to SDIC#k) is the same, in FIG. 3, for convenience of explanation, one source driver IC (SDIC) among the plurality of source driver ICs (SDIC#1 to SDIC#k) is shown. ) will only be explained.

As shown 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.

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

The source signal input unit 310 receives image data from the timing controller 11 when driving in normal mode, and converts the received image data into a source signal (Vdata_D) for image display according to the source control signal (SDC). This is supplied to each data line (14A). In addition, the source signal input unit 310 receives sensing data from the timing controller 11 when driving in the sensing mode and converts the received sensing data into 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 effective 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 the effective sensing data into a valid sensing source signal during the sensing period and supplies it to the data lines 14A, and supplies the reference sensing data to the reference sensing source signal. 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) and senses the 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.

Figure 4 is a block diagram schematically showing the configuration of a sensing block according to the 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 .

Sensing units (SU#1 to SU#n) are connected to each sensing channel (CH#1 to CH#n) and obtain a sensing value by sensing the pixel (P) connected to the corresponding sensing channel (CH1 to CHn). Specifically, the sensing units (SU#1 to SU#n) provide the effective sensing value obtained from the driving transistor of each pixel (P) according to the supply of the effective sensing source signal to each pixel (P) in the sensing section and the effective sensing value obtained from the driving transistor of each pixel (P). The reference sensing value obtained from the driving transistor of each pixel (P) is acquired according to the supply of the reference sensing source signal to (P).

At this time, the sensing values obtained by the sensing units (SU#1 to SU#n) may include white noise, common noise, and the offset of the sensing units (SU#1 to SU#n). White noise is a noise that exists in nature and appears randomly every time it is sensed, and its value converges to 0 as sensing is repeated. Common noise is noise generated in the driving environment and occurs randomly, but unlike white noise, it commonly affects all sensing units (SU#1 to SU#n) and converges to an unknown value even if sensing is repeated. There is a characteristic. Offset is a characteristic that occurs due to process deviation of sensing units (SU#1 to SU#n) and has a characteristic of having similar values between adjacent sensing units (SU#1 to SU#n).

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

That is, during one-time sensing, the source signal input unit 310 applies a source signal (Valid) for valid sensing to each pixel (P) connected to the odd sensing channel, and applies a source signal (Valid) for reference sensing to each pixel (P) connected to the even sensing channel. When a source signal (Reference) is applied, the sensing units (SU#1 to SU#n) obtain the effective sensing value from the odd sensing channel connected to the pixel (P) to which the valid sensing source signal (Valid) has been applied, and the reference The reference sensing value is obtained from the even sensing channel connected to the pixel (P) to which the sensing source signal (Reference) has been applied.

The sensing units (SU#1 to SU#n) transmit the effective sensing value obtained through the odd sensing channel and the reference sensing value 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 the reference sensing value according to the application of the reference sensing source signal (Reference) from the odd sensing channel in the sensing section, and even The effective sensing value is obtained according to the application of the valid sensing source signal (Valid) 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 applies a source signal (Reference) for effective sensing to each pixel (P) connected to the even sensing channel. When the source signal (Valid) is applied, the sensing unit (SU#1 to SU#n) obtains a valid sensing value through the even sensing channel connected to the pixel (P) to which the valid sensing source signal (Valid) has been applied, and the reference The reference sensing value is obtained through the odd sensing channel connected to the pixel (P) to which the sensing source signal (Reference) has been applied.

The sensing units (SU#1 to SU#n) transmit the reference sensing value obtained through the odd sensing channel and the effective sensing value 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, with reference to FIG. 7, the configuration of the sensing units (SU#1 to SU#n) that obtain the current value between the source and drain of the driving transistor as a sensing value will be briefly described.

Figure 7 is a block diagram showing the configuration of a current sensing sensing unit 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 the pixel current from the sensing line 14B through the sensing channel CH and outputs the integrated pixel current. For this purpose, the current integrator 710 includes an amplifier (AMP), an integrating capacitor (Cfb), and a reset switch (RST).

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

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

Since the method by which the current integrator 710 integrates the current (Ids) between the source and drain of the driving transistor and outputs the integrated value (Vout) is a known technology, detailed description 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 integrated 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 is explained that the sensing unit senses the characteristics of the driving transistor using a current sensing method, but the sensing unit according to the present invention is not limited to this and may sense the characteristics of the driving transistor using a voltage sensing method. According to this embodiment, the current integrator 710 in the configuration of the sensing unit shown in FIG. 7 may be omitted.

Referring again to FIG. 3, 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 the reference sensing value into a digital value. Convert. The analog-to-digital converter 400 provides effective sensing values and reference sensing values converted to digital values to the sensing data calculation unit 410.

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

Specifically, the sensing data calculation unit 410 differentiates the digital value of the effective sensing value obtained from the odd sensing channel during one-time sensing and the digital value of the reference sensing value obtained from the even sensing channel, thereby generating a pixel (pixel) connected to the odd sensing channel. Obtain the real sensing value (RSD) of P).

In addition, the sensing data calculation unit 410 determines the real data of the pixel connected to the even sensing channel by differentiating 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. Obtain the sensing value (RSD).

The method by which the sensing data calculation unit 410 obtains the real sensing value (RSD) for the S-th sensing channel is expressed as 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 the source signal for effective sensing is applied to the pixel (P) connected to the S-th sensing channel. , DSD#S+1 represents the reference sensing value obtained when the source signal for reference sensing is applied to the pixel (P) connected to the S+1th sensing channel, and DSD#S-1 represents the S-1th sensing channel. It represents the reference sensing value obtained when the source signal for reference sensing is applied to the pixel (P) connected to the channel.

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

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 re-expressed using equations 3 to 5, they can be expressed as equations 6 and 7 below.

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

As can be seen from the above-mentioned equations 8 and 9, if the sensing values obtained from the odd and even sensing channels adjacent to each other are differentially operated, common noise and offset are removed from the effective sensing values obtained from each sensing channel. there is.

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

Hereinafter, a method for the sensing block 320 according to the present invention to obtain 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 Equations 1 to 9 above to the first sensing channel (CH#1) and the second sensing channel (CH#2), the real sensing value for the first sensing channel (CH#1) is ( RSD#1) can be calculated as in Equation 10, and the real sensing value (RSD#2) for the second sensing channel (CH#1) can be calculated as in Equation 11.

At this time, white noise can be additionally removed by repeating the above-described sensing process multiple times.

In the above-described embodiment, the sensing data calculation unit 410 differentiates the effective sensing value and the reference sensing value obtained by the corresponding sensing units (SU#1 to SU#n) for each sensing channel to determine the pixel connected to each sensing channel. It was explained that the real sensing value (RSD) of is directly calculated. 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 transmits the effective sensing value and the reference sensing value. By performing a differential operation on each sensing channel, the real sensing value (RSD) of the pixel (P) connected to each sensing channel may be obtained.

Additionally, in the above-described embodiment, after the ADC 400 converts the effective sensing value and the reference sensing value into digital values, the sensing data calculation unit 410 converts the digital values of the effective sensing value and the reference sensing value into digital values. It was explained as differential. However, in another embodiment, the sensing data calculation unit 410 calculates a real sensing value by performing a differential operation on the effective sensing value and the reference sensing value, and the ADC 400 converts the real sensing value into a digital value and uses the timing controller ( 11) You can also send it to 11).

Meanwhile, in the above-described first embodiment, the sensing block 320 performs a differential operation on the effective sensing value and the reference sensing value obtained from two adjacent sensing channels when calculating the real sensing value (RSD) to offset common noise and offset. It was explained as follows. In this first embodiment, the entire sensing is performed twice, but when sensing once, only the real sensing value of the odd sensing channel can be acquired, and when sensing twice, only the real sensing value of the even sensing channel can be acquired. Since this is possible, the result is the same as if sensing was performed once, resulting in a sensing efficiency of 50%.

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

Therefore, the following will describe the configuration of a sensing block that can reduce common noise and offset while having higher sensing efficiency or reduce the number of sensing channels or sensing units compared to the first embodiment.

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, it has n sensing units (SU#1 to SU#n). Sensing groups are formed by grouping m units, and sensing is performed for each sensing group. That is, in the second embodiment, the sensing block 320 performs sensing in units of sensing groups composed of m sensing units (SU#1 to SU#m).

In addition, in the first embodiment, the real sensing value (RSD) was calculated by assuming that the offsets of adjacent sensing units have similar values, but in the second embodiment, in order to obtain a more accurate real sensing value (RSD), each The offset is directly calculated 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. Figure 8 is a table showing the sensing method according to the second embodiment of the present invention, and Figure 9 is a timing diagram showing the sensing method according to the second embodiment.

In Figures 8 and 9, for convenience of explanation, one sensing group (SG) is shown as consisting of 8 sensing units, but this is only an example. One sensing group (SG) consists of 9 or more sensing units or 2 It may be composed of one to seven sensing units. In addition, hereinafter, for convenience of explanation, the second embodiment will be described based on the eight sensing units (SU#1 to SU#8) included in the first sensing group (SG1).

When operating in the sensing mode, 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 period and during the effective sensing period. Effective sensing is performed for each pixel (P).

The sensing units (SU#1 to SU#8) use the sensing value obtained from the 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). At this time, 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, because the obtained sensing value includes white noise, each sensing unit (SU#1 to SU#8) performs sensing using the source signal for offset sensing multiple times for each pixel (P). White noise can be reduced by repetition. According to this embodiment, the sensing units (SU#1 to SU#8) calculate the average value of the sensing values calculated for each sensing session as the offset of the corresponding sensing units (SU#1 to SU#8). You can.

As such, in the second embodiment, each sensing unit (SU#1 to SU#8) uses the sensing value obtained when the source signal for offset sensing is applied to each pixel (P) during the offset sensing period. Because the offset of the units (SU#1 to SU#8) is directly calculated, it is possible to obtain more accurate real sensing values compared to the first embodiment, which offsets the offset based on the assumption that the offsets of adjacent sensing units are similar. .

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

That is, during the effective sensing period, the source signal input unit 310 applies the source signal for effective sensing to pixels connected to seven sensing units (e.g., SU#1 to SU#7) and transmits the source signal to one sensing unit (e.g., SU#8). ) Apply the source signal for reference sensing to the pixel connected to ). Accordingly, during the effective sensing period, 7 effective sensing values are obtained by 7 sensing units (SU#1 to SU#7) connected to the pixels to which the source signal for reference sensing is applied, and the pixels to which the source signal for reference sensing is applied. One reference sensing value is obtained 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 for each pixel eight times, but the source signal input unit 310 uses a reference sensing source for each sensing round. Changes the pixel to which the signal will be applied. That is, the source signal input unit 310 applies the source signal for reference sensing to the pixel connected to the 8th sensing channel (CH#8) when sensing once, and to the pixel connected to the 7th sensing channel (CH#7) when sensing twice. The source signal for reference sensing is applied to the pixel connected to the 6th sensing channel (CH#6) for the 3rd sensing, and the 5th sensing channel (CH#5) for the 4th sensing. A 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 the pixel connected to the 4th sensing channel (CH#4) when sensing 5 times, and to the pixel connected to the 3rd sensing channel (CH#3) when sensing 6 times. The source signal for reference sensing is applied to the pixel. For the 7th sensing, the source signal for reference sensing is applied to the pixel connected to the 2nd sensing channel (CH#2), and for the 8th sensing, the source signal for reference sensing is applied to the 1st sensing channel (CH#1). Apply the source signal for reference sensing to the pixel connected to . Accordingly, 7 effective sensing and 1 reference sensing are performed for each sensing channel included in the first sensing group (SG1).

As such, in the second embodiment, sensing is performed 8 times while varying the pixel to which the reference sensing source signal is applied for each sensing round, and as a result of the 8 sensing times, 7 for each sensing unit (SU#1 to SU#8). Since effective sensing values are obtained, a sensing efficiency of 87.5% can be achieved, improving the sensing efficiency compared to the first embodiment.

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

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

The sensing data calculation unit 410 differentially calculates the digital value for each of the seven effective sensing values obtained by seven sensing units for each sensing round and the digital value for the reference sensing value obtained by one sensing unit. By doing so, the real sensing value (RSD) for the pixels connected to the 7 sensing units that obtained the effective sensing value is obtained.

If this is expressed mathematically, it is expressed as Equation 12 below.

In Equation 12, RSD#S refers to the real sensing value of the pixel connected to the S-th sensing channel (CH#S), and VSD#S refers to the effective sensing value of the pixel (P) connected to the S-th sensing channel (CH#S). It represents the effective sensing value obtained when the source signal is applied, OS#S means the average of the offset obtained through multiple offset sensing by the sensing unit (SU#6) connected to the S-th sensing channel, and DSD# R means the reference sensing value obtained when a signal for reference sensing is applied to the pixel (P) connected to the Rth sensing channel (CH#R), and OS#R is the reference sensing value obtained when the signal for reference sensing is applied to the pixel (P) connected to the Rth sensing channel (CH#R). It means the average of the offset obtained by the sensing unit (SU#R) 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 below, respectively, Equation 12 is It can be re-expressed as Equation 15 below using Equation 3 and Equations 13 and 14 below.

At this time, CN' is the average value of common noise generated during offset sensing, and Equation 15 can be re-expressed as Equation 17 below.

In this way, the sensing units (SU#1 to SU#8) according to the second embodiment vary as the pixel to which the reference sensing source signal is applied for each sensing round changes. For each pixel connected to 1~SU#8), 7 effective sensing and 1 reference sensing are performed to obtain 7 effective sensing values and 1 reference sensing value. In addition, the sensing data calculation unit 410 differentiates the effective sensing value and the reference sensing value for each sensing unit (SU#1 to SU#8), thereby generating By obtaining 7 real sensing values (RSD) for each sensing unit (SU#1~SU#8) and averaging the 7 real sensing values (RSD) obtained for each sensing unit (SU#1~SU#8), the corresponding sensing units (SU#1~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, CH#2) included in the first sensing group (SG1). Examples of are described with reference to Tables 1 and 2 below and FIGS. 8 and 9. Table 1 shows a method for calculating the real sensing value of a pixel connected to the first sensing channel (CH#1), and Table 2 shows a method for calculating the real sensing value of a pixel connected to the second sensing channel (CH#2). It represents.

When the pixel to which the reference source signal is applied for each sensing round changes according to the order 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) acquires 7 effective sensing values (VSD) by sensing pixels connected to the first sensing channel (CH#1). In addition, the sensing units (SU#2~SU#8) connected to the second to eighth sensing channels (CH#2~CH#8) are connected to the corresponding sensing channels (CH#2~CH#8) for each sensing round. Each reference sensing value (DSD) is acquired based on the reference sensing signal applied to the connected pixel. Afterwards, the sensing data calculation unit 410 differentially calculates the effective sensing value (VSD) and the reference sensing value (DSD) for each sensing session, averages the differential calculation results, and outputs the values to the first sensing channel (CH#1). Calculate the real sensing value (RSD) of the connected pixel.

Similarly, when the pixel to which the reference source signal is applied for each sensing round is varied according to the order shown in FIGS. 8 and 9, the pixel to which the reference source signal is applied is changed in the second sensing channel (CH#2) as shown in Table 2. The connected second sensing unit (SU#2) acquires 7 effective sensing values (VSD) by sensing pixels connected to the second sensing channel (CH#2). In addition, the sensing units (SU#1, SU#3~SU#8) connected to the first sensing channel (CH#1) and the third to eighth sensing channels (CH#3 to CH#8) are connected to each sensing session. Each reference sensing value (DSD) is acquired based on the reference sensing signal applied to the pixel connected to the corresponding sensing channel. Afterwards, the sensing data calculation unit 410 differentially calculates the effective sensing value (VSD) and the reference sensing value (DSD) for each sensing session, averages the differential calculation results, and outputs the values to the second sensing channel (CH#2). Calculate the real sensing value (RSD) of the connected pixel.

In this way, according to the second embodiment, since the offset of each sensing unit (SU#1 to SU#8) is directly calculated, more accurate real sensing values can be obtained than the first embodiment, and sensing is performed 8 times during effective sensing. By performing this, 7 effective sensing values are obtained for each sensing unit (SU#1 to SU#8), resulting in 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 sensing unit for reference sensing are not required, the size of the source driver IC and display panel can be reduced, as well as the manufacturing cost of the display panel.

3rd Example

FIG. 10 is a diagram showing the 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 shown in FIG. 10, unlike the sensing block 320 shown in FIG. 4, it additionally includes n/2 muxes (MUX, 1000) with an input and output ratio of 2:1. Due to this MUX 1000, the number of sensing units (SU) (n/2) is reduced by half compared to the number of sensing units (SU) (n) according to the first and second embodiments. Able to know. Accordingly, in the case of the third embodiment, not only can the size of the source driver IC and the size of the display panel be further reduced, but also the amount of data transmitted from the sensing block 320 to the timing controller 11 can 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). The sensing block 320 according to the third embodiment has a structure in which two adjacent sensing channels are connected to one sensing unit through the mux 1000, so that m sensing units (m) included in one sensing group (SG) SU#1~SU#m) senses pixels connected to 2m sensing channels (CH#1~CH#2m).

According to the above-described embodiment, the MUX 1000 uses m odd sensing channels among the 2m sensing channels (CH#1 to CH#2m) included in one sensing group (SG) into m sensing units (SU). #1~SU#m), and the m sensing units (SU#1~SU#m) perform sensing on the 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 uses the remaining m even sensing channels among the 2m sensing channels (CH#1 to CH#2m) included in the sensing group (SG) into m sensing units ( SU#1~SU#m), and the m sensing units (SU#1~SU#m) perform sensing on the m even sensing channels in the same manner as in the second embodiment, so that 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 8 sensing units (SU#1 to SU#8), and the 8 sensing units (SU#1 to SU#8) have 16 sensing channels ( Although it is shown as sensing pixels connected to CH#1 to CH#16), this is only an example, and one sensing group (SG) may be 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).

When operating in the sensing mode, 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 period and detect the offset of each sensing unit (SU#1 to SU#8) during the effective sensing period. 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), the m sensing units (SU#1 to SU#8) connected to the odd sensing channels ) is the offset of m sensing units (SU#1 to SU#8) connected to the odd sensing channel using the sensing value obtained from the corresponding pixel when the source signal for offset sensing is applied to each pixel during the offset sensing section. Calculate In addition, when the MUX 1000 connects m even sensing channels to m sensing units (SU#1 to SU#8), the m sensing units (SU#1 to SU#8) connected to the even sensing channels 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 corresponding pixel. .

At this time, similar to the second embodiment, the sensing values obtained by the m sensing units (SU#1 to SU#8) include white noise, so the m sensing units (SU#1 to SU#8) ) can reduce white noise by repeating sensing using the source signal for offset sensing multiple times for each pixel. According to this embodiment, the m sensing units (SU#1 to SU#8) can calculate the average of the sensing values calculated for each sensing session as the offset of the corresponding sensing unit.

In the above-described embodiment, it was explained that the offset of m sensing units (SU#1 to SU#8) is calculated by dividing them into odd sensing channels and even sensing channels. However, in the modified embodiment, the offset of the sensing unit may be constant regardless of whether the sensing channel connected to the sensing unit is an odd sensing channel or an even sensing channel, so that m sensing units (SU#1 to SU#8) The offset may be calculated based on when any one of the odd sensing channel or the even sensing channel is connected.

Meanwhile, in the effective sensing section, when the MUX 1000 connects m odd sensing channels to 8 sensing units (SU#1 to SU#8), the 8 sensing units (SU#1 to SU#8) connected to the odd sensing channels #8) Any one of the sensing units acquires a reference sensing value when a source signal for reference sensing is applied from a pixel connected to the corresponding sensing unit. Additionally, the remaining seven sensing units obtain effective sensing values when a source signal for effective sensing is applied from a pixel connected to the corresponding sensing unit. At this time, as in the second embodiment, the sensing units (SU#1 to SU#8) repeat the above-described sensing process eight times for each pixel, and the source signal input unit 310 performs each sensing process. The source signal for reference sensing is applied while varying the pixel to which the source signal for reference sensing is applied for each turn.

Afterwards, when the MUX (1000) connects m even sensing channels to 8 sensing units (SU#1 to SU#8), among the 8 sensing units (SU#1 to SU#8) connected to the even sensing channels, One sensing unit obtains a reference sensing value when a source signal for reference sensing is applied from a pixel connected to the corresponding sensing unit. Additionally, the remaining seven sensing units obtain effective sensing values when a source signal for effective sensing is applied from a pixel connected to the corresponding sensing unit. At this time, as in the second embodiment, eight sensing units (SU#1 to SU#8) repeat the above-described sensing process eight times for each pixel, and the source signal input unit 310 performs each pixel. The source signal for reference sensing is applied while varying the pixel to which the source signal for reference sensing is applied for each sensing session.

When the odd sensing channel is connected to the sensing units (SU#1 to SU#8) by the mux 1000, the ADC (400) generates 7 effective sensing values obtained by 7 sensing units for each sensing session and Each reference sensing value obtained by one sensing unit is converted into a digital value and provided to the sensing data calculation unit 410.

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

The sensing data calculation unit 410 calculates a digital value for each of the seven effective sensing values obtained by seven sensing units for each sensing session for odd sensing channels and a reference sensing value obtained by one sensing unit. Real sensing values for pixels connected to the odd sensing channel are obtained by differentially calculating the digit value and averaging the differential calculation results.

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

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

In Figure 10, a plurality of muxes 1000 are shown as being included within the sensing block 320. However, in another embodiment, as shown in FIG. 12, a plurality of muxes 1000 are disposed outside the sensing block 320 to connect two adjacent sensing lines 14B to one sensing channel CH. You might be able to do it. In one embodiment, a plurality of muxes 1000 may be formed on the display panel.

4th Example

Figure 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. As shown in FIG. 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 further includes one dummy sensing line (14D) connected to a plurality of dummy pixels (D). In addition, the source driver IC (SDIC) has one dummy sensing channel (CH#D) connected to one dummy sensing line (14D) and one dummy sensing unit (SU#D) connected to the dummy sensing channel (CH#D). ) is additionally included.

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 period, and each sensing unit (SU#1~SU#n) The offset of SU#n) is calculated, and the dummy sensing unit (SU#D) performs offset sensing on the dummy pixel connected to one dummy sensing channel (CH#D) to determine the offset of the dummy sensing unit (SU#D). Calculate . Since the offset calculation method is the same as that described in the second embodiment, detailed description is omitted.

Afterwards, during the effective sensing period, each sensing unit (SU#1 to SU#n) performs effective sensing when a source signal for effective sensing is supplied from pixels connected to n sensing channels (CH#1 to CH#n). The dummy sensing unit (SU#D) acquires the dummy sensing value when the 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 by 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 operates the sensing data calculation unit ( 410) is a pixel connected to each sensing unit (SU#1~SU#n) by performing a differential operation on the digital value of the effective sensing value and the digital value of 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 was explained 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 are grouped into one sensing group. ) may perform sensing m times for each sensing channel. Hereinafter, these details will be described in detail with reference to FIG. 14.

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

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

During the effective sensing period, eight sensing units (SU#1 to SU#8) included in one sensing group receive a source signal for effective sensing from the pixel to which the corresponding sensing unit (SU#1 to SU#8) is connected. An 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. At this time, the dummy source signal may be the same signal as the reference sensing source signal in the above-described embodiment.

Afterwards, the ADC 400 converts the effective sensing values obtained by each of the eight sensing units (SU#1 to SU#8) and the dummy sensing values obtained by the dummy sensing unit (SU#D) into digital values, and performs sensing The data calculation unit 410 performs a differential operation on the digital value of the effective sensing value and the digital value of the dummy sensing value to obtain a real sensing value for each of the eight sensing units (SU#1 to SU#8). At this time, as described above, each sensing unit (SU#1 to SU#8) performs sensing 8 times, so 8 real sensing values are calculated for each sensing unit (SU#1 to SU#8), so the sensing The data calculation unit 410 calculates the final real sensing value of each sensing unit (SU#1 to SU#8) by averaging the eight real sensing values.

In this way, by adding the dummy sensing channel (14D) and the dummy sensing unit (SU#D) according to the fourth embodiment, it is possible to obtain real sensing values for all m channels by sensing m times, thereby increasing sensing efficiency. It can be increased up to 100%.

In another embodiment, the sensing block 320 includes one dummy sensing channel (14D) and a dummy sensing unit (SU#D), and, similar to the third embodiment, any of the two adjacent sensing channels It may additionally include a plurality of muxes (not shown) connecting one to one sensing unit.

According to this embodiment, during one-time sensing, the odd sensing channels included in one sensing group are connected to each sensing unit (SU#1 to SU#8) through the mux, so that each sensing unit (SU#1 to SU#8) 8) The effective sensing value is obtained by sensing the pixels connected to this odd sensing channel, and at the same time, one dummy sensing unit (SU#D) senses the pixels connected to the dummy sensing channel (CH#D) to obtain a dummy sensing value. Acquire.

Similarly, during second sensing, the even sensing channels included in one sensing group are connected to each sensing unit (SU#1~SU#8) through MUX, so that each sensing unit (SU#1~SU#8) Effective sensing values are obtained by sensing pixels connected to the even sensing channel, and at the same time, one dummy sensing unit (SU#D) acquires a dummy sensing value by sensing pixels connected to the dummy sensing channel (14D).

According to this embodiment, pixels connected to 8 odd sensing channels can be sensed in one sensing, so sensing efficiency can be improved compared to the third embodiment in which 7 odd sensing channels can be sensed 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 understand that the above-described present invention can be implemented in other specific forms without changing its technical idea or essential features.

For example, in the above-described embodiment, the sensing block is shown as being included in the source driver IC, but this is only an example and the sensing block may be implemented in a configuration that is physically separate from the source driver IC.

Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being 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 unit
320: Sensing block 330: Analog digital converter
340: Sensing data calculation unit

Claims (20)

One reference sensing channel connected to pixels through m (m is an integer of 2 or more) sensing channels, and sensing the pixel m times during the effective sensing period, to which a source signal for reference sensing is applied for each sensing session. A sensing block that obtains a reference sensing value through and obtains an effective sensing value through m-1 effective sensing channels connected to pixels to which a source signal for effective sensing is applied; and
A sensing data calculation unit that calculates a real sensing value for each sensing channel using a difference between an effective sensing value obtained through the effective sensing channel for each sensing session and a reference sensing value obtained through the reference sensing channel,
A source driver IC for sensing the characteristics of a driving transistor, wherein the process of varying the pixel to which the reference sensing source signal is applied is repeated for at least m each sensing round. According to paragraph 1,
The sensing data calculation unit 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 for each sensing session and the reference sensing value obtained through the reference sensing channel. A source driver IC for sensing the characteristics of a driving transistor. According to paragraph 1,
The sensing block acquires an offset according to application of a source signal for offset sensing for each sensing channel during the offset sensing section before the effective sensing section,
The sensing data calculation unit obtains a first result value obtained by subtracting an offset obtained through the effective sensing channel from the effective sensing value obtained through each effective sensing channel for each sensing session and a reference sensing channel for each sensing session. For sensing the characteristics of a driving transistor, characterized in that the real sensing value is calculated for each sensing channel by averaging the differential value between the second result value obtained by subtracting the offset obtained through the corresponding reference sensing channel from the reference sensing value. Source driver IC. According to clause 3,
The sensing block corrects the offset by reducing white noise at the offset of each sensing channel,
A source driver IC for sensing characteristics of a driving transistor, wherein the sensing data calculation unit calculates a real sensing value of each sensing channel using a corrected offset. According to clause 4,
The sensing block is a source for sensing the characteristics of a driving transistor, characterized in that the white noise is reduced from the offset by averaging a plurality of offsets obtained by sensing each pixel for each sensing channel multiple times during the offset sensing period. Driver IC. According to paragraph 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 supplies the source signal for reference sensing to pixels connected to the one reference sensing channel. Further comprising a signal input unit,
A source driver IC for sensing characteristics of a driving transistor, wherein the source signal input unit changes a pixel to which the reference sensing source signal is applied for each sensing cycle. According to paragraph 1,
Sensing characteristics of a driving transistor, wherein the source signal for reference sensing is a signal having a voltage level corresponding to a black gradation, and the source signal for effective sensing is a signal having a voltage level corresponding to a gradation higher than the black gradation. Source driver IC for. According to paragraph 1,
The effective sensing value is obtained using the current value between the source and drain of the driving transistor included in the pixel when the effective sensing source signal is supplied to the pixels connected to the effective sensing channel,
The reference sensing value is obtained using the current value between the source and drain of the driving transistor included in the pixel when the source signal for reference sensing is supplied to the pixel connected to the reference sensing channel. Source driver IC for characteristic sensing. According to paragraph 1,
It further includes an analog-to-digital converter (ADC) that converts the effective sensing value obtained from the effective sensing channel for each sensing session and the reference sensing value obtained from the reference sensing channel into digital values, respectively,
A driving transistor characterized in that the sensing data calculation unit calculates the real sensing value of each sensing channel by differentially calculating 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 driver IC for sensing characteristics. According to paragraph 1,
The sensing block is connected 1:1 to the m sensing channels and includes m sensing units that obtain the reference sensing value or the effective sensing value from pixels connected to each sensing channel. Source driver IC for characteristic sensing. According to clause 10,
The sensing unit is,
During the effective sensing period, the current value between the source and drain of the driving transistor included in the pixel connected to the effective sensing channel or the current value between the source and drain of the driving transistor included in the pixel connected to the reference sensing channel are accumulated. an integrator that generates an output value; and
A source driver IC for sensing characteristics of a driving transistor, comprising a sample and hold circuit connected to the output terminal of the integrator to sample the output value and output it as the effective sensing value or the reference sensing value. According to clause 10,
The m sensing units form one sensing group,
A source driver IC for sensing characteristics of a driving transistor, wherein the sensing block includes a plurality of sensing groups. A plurality of muxes that select one of the odd and even sensing channels adjacent to each other among 2m sensing channels;
During the effective sensing period, the m sensing channels connected through the plurality of muxes are sensed m times, and a reference sensing value is obtained through one reference sensing channel connected to the pixel to which the reference sensing source signal is applied for each sensing session, and the effective sensing value is obtained. A sensing block that obtains an effective sensing value through m-1 effective sensing channels connected to pixels to which a sensing source signal is applied; and
A sensing data calculation unit that calculates a real sensing value for each sensing channel using a difference between an effective sensing value obtained through the effective sensing channel for each sensing session and a reference sensing value obtained through the reference sensing channel,
A source driver IC for sensing the characteristics of a driving transistor, wherein the process of varying the pixel to which the reference sensing source signal is applied is repeated for at least m each sensing round. According to clause 13,
The plurality of muxes connect m odd sensing channels to the sensing block during a first sensing section among the effective sensing sections and connect m even sensing channels to the sensing block during a second sensing section,
The sensing block senses the m odd sensing channels m times during the first sensing period, obtains a reference sensing value from one reference sensing channel among the m odd sensing channels, and performs effective sensing from m-1 effective sensing channels. A value is acquired, and during the second sensing period, the m even sensing channels are sensed m times to obtain a reference sensing value from one reference sensing channel among the m even sensing channels and a valid sensing value from m-1 effective sensing channels. Obtaining the sensing value,
The sensing data calculation unit calculates real sensing values for the m odd sensing channels during a first sensing period and calculates real sensing values for the m even sensing channels during a second sensing period. Source driver IC for sensing the characteristics of transistors. According to clause 13,
The sensing block obtains an offset according to application of a source signal for offset sensing from the odd sensing channel and the even sensing channel during the offset sensing section before the effective sensing section,
The sensing data calculation unit calculates a first result value obtained by subtracting the offset obtained through the effective sensing channel from the effective sensing value obtained from each effective sensing channel for each sensing session and a reference obtained from the reference sensing channel for each sensing session. A source driver IC for sensing the characteristics of a driving transistor, characterized in that the real sensing value is calculated for each sensing channel by averaging the differential value between the second result value obtained by subtracting the offset obtained through the corresponding reference channel from the sensing value. . According to clause 15,
The sensing block senses each pixel multiple times through each sensing channel during the offset sensing period and averages the plurality of offsets obtained for each sensing channel to correct the offset.
A source driver IC for sensing characteristics of a driving transistor, wherein the sensing data calculation unit calculates a real sensing value of each sensing channel using a corrected offset. According to clause 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 source signal for reference sensing is supplied to pixels connected to one reference sensing channel. supplies a source signal, and supplies the source signal for effective sensing 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. It further includes a source signal input unit that supplies the reference sensing source signal to the pixel,
A source driver IC for sensing characteristics of a driving transistor, wherein the source signal input unit changes a pixel to which the source signal for reference sensing is applied for each of the sensing rounds during the first and second sensing periods. According to clause 13,
Sensing characteristics of a driving transistor, wherein the source signal for reference sensing is a signal having a voltage level corresponding to a black gradation, and the source signal for effective sensing is a signal having a voltage level corresponding to a gradation higher than the black gradation. Source driver IC for. According to clause 13,
Further comprising an analog-to-digital converter that converts the effective sensing value and the reference sensing value obtained for each sensing session into digital values for each sensing channel,
The sensing data calculation unit calculates the real sensing value of each sensing channel using the result of differentiating the digital value of the effective sensing value and the digital value of the reference sensing value output from the analog-to-digital converter. A source driver IC for sensing the characteristics of a driving transistor. According to clause 13,
The sensing block is selectively connected to one of an odd sensing channel and an even sensing channel adjacent to each other 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, the sensing block obtains the reference sensing value or the effective sensing value from the odd sensing channel. A source driver IC for sensing characteristics of a driving transistor, comprising m sensing units that obtain the reference sensing value or the effective sensing value from an even sensing channel.

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