JP5068492B2 - Display device data driver driving method, display device data driver, and display device - Google Patents

Description

  The present invention relates to an integrated circuit device, and more particularly to a data driver circuit and a driving method of a display device.

  An organic light emitting diode (OLED) display device has excellent linearity in the current and luminance of the device, and thus it is easy to adjust the luminance by controlling the current flowing through the device. Generally, an OLED display device is divided into an active matrix system and a passive matrix system according to its driving system. In the active matrix system, the luminance is adjusted by adjusting the voltage and current of the element. In the passive matrix system, the luminance is adjusted by adjusting the duty ratio of the drive signal. Although image data is proportional to light intensity, image display devices typically have a non-linear relationship between input image data (gradation input) and output luminance. In general, a graph of gradation input and output luminance in many display devices has an exponential curve, and the exponent value of such a curve is called gamma. If the gamma value is set incorrectly, the displayed image will be distorted and the image quality will deteriorate. Different image display devices can have different optimum gamma values applied to optimize the quality of the displayed image. In the OLED display device, the driving circuit adjusts the driving current of the driving transistor.

Japanese Patent Application Laid-Open Publication No. 2004-228688 discloses a gamma correction circuit that realizes a good gradation of a display image in a display device such as a liquid crystal display device or a plasma display panel.
FIG. 1 is a block diagram of a data driver circuit of a display device for conventional gamma correction.

  The data driver circuit 20 includes a control unit 21, a lookup table 22, and a plurality of digital / analog conversion units (DAC) 23. The lookup table 22 includes corrected gamma values for the red (R), blue (B), and green (B) color intensities of each pixel. The control unit 21 receives video data or color data 27 and a lookup table setting command word 29 from the external control unit 25, and receives 8-bit gamma-corrected gradation data 26 from the lookup table 22. In order to implement 260K color, 6-bit color data is assigned to each of R, G, and B. The control unit 21 receives the 6-bit color data 27 and the 8-bit lookup table setting command 29 from the external control unit 25 and provides the 6-bit color data 24 to the input of the lookup table 22. In response to this, the look-up table 22 outputs the 8-bit gradation data 26 subjected to gamma correction to the control unit 21 again. The 8-bit gradation data 26 is generated by gamma-correcting the 6-bit color data 24 and adding a 2-bit dummy bit. The 8-bit gradation data 28 is supplied to the DAC 23, and the DAC 23 generates a data current (IDATA) in response thereto.

The look-up table 22 and the DAC 23 occupy a wide chip area, and the circuit implementation is complicated by 2-bit dummy bits added using the 8-bit gradation data 26. In addition, it is necessary to periodically reflash the mapping data included in the lookup table in comparison with system noise.
Japanese Published Patent No. 11-288241

  A first object of the present invention is to provide a current-driven data driver for a display device that can reduce the chip size of the data driver during gamma correction.

  A second object of the present invention is to provide a display device having the data driver.

  A third object of the present invention is to provide a data line driving method using the data driver.

  A method of driving a data driver of a display device according to an embodiment of the present invention includes generating L gray scale reference currents corresponding to values other than a zero gray level, and the L levels in response to a gamma signal. A step of selecting M gamma reference currents from the adjustment reference current, a step of generating a zero gradation level gamma reference voltage, and selecting one of the M gradation reference currents in response to a color signal. Or selecting the zero level gamma reference voltage and generating a data current in response to one or zero gray level gamma reference voltage from the selected M gray level reference currents. .

  In some embodiments, selecting the M gamma reference currents includes decoding the gamma signal to generate a gamma current selection signal, and the M gamma current selection signals in response to the gamma current selection signal. Driving M gamma selection switches for selecting gamma reference currents, respectively.

  In an embodiment, generating the L gray scale reference currents may include using a current mirror composed of L transistors having different widths.

  In an embodiment, selecting one or zero gray level gamma reference voltage from the M gray scale reference currents generates M gamma reference voltages based on each of the M additional gamma reference currents. And selecting one of the M + 1 gamma reference voltages in response to the color signal, wherein the step of generating the data current includes selecting one of the selected N + 1 gamma reference voltages. The data current can be generated in response to one of them.

  In one embodiment, selecting one of the M + 1 gamma reference voltages includes decoding the color signal to generate a gamma reference voltage selection signal, and the selected M + 1 gamma reference voltages. Driving one of M + 1 switches corresponding to the M + 1 gamma reference voltages in response to the gamma reference voltage selection signal. it can.

  In some embodiments, generating the data current includes driving a data current transistor connected to the output node using one of the selected M + 1 gamma reference voltages. The method may further include limiting the data current using a clamp circuit.

  In some embodiments, generating the M additional gamma reference voltages based on each of the M gamma reference currents includes generating the M gamma reference voltages in response to each of the M gamma reference currents. Using M current-voltage conversion circuits for additional generation.

  According to another embodiment of the present invention, a method of driving a data driver of a display device includes generating L reference currents corresponding to a value other than a zero gray level, and the L drivers in response to a gamma signal. Selecting M gamma reference currents from a plurality of gradation reference currents and generating a zero gradation level gamma reference voltage. For each of a plurality of data lines, selecting one of the M gamma reference currents or selecting the zero gray level gamma reference voltage in response to a color signal; and selecting the selected M Generating a data current in response to one or the zero gray level gamma reference voltage from a plurality of gamma reference currents. The method further includes driving the plurality of scan lines to select a plurality of pixels respectively determined by one of the plurality of data lines and one of the plurality of scan lines.

  According to another embodiment of the present invention, a method of driving a data driver of a display device includes generating L gray scale reference currents, and M gammas from the L gray scale reference currents in response to a gamma signal. Selecting a reference current; and generating a data current in response to any one of the M gray scale reference currents in response to a color signal.

  In some embodiments, selecting the M gamma reference currents includes decoding the gamma signal to generate a gamma current selection signal, and the M gamma current selection signals in response to the gamma current selection signal. Driving M gamma selection switches for selecting gamma reference currents, respectively.

  In an embodiment, generating the L gray scale reference currents may include using a current mirror composed of L transistors having different widths.

  In one embodiment, selecting one of the M gray scale reference currents includes generating M gamma reference voltages based on each of the M gamma reference currents, and responding to the color signal. Selecting one of the M gamma reference voltages and generating the data current in response to any one of the selected M gamma reference voltages. A step of generating a current can be included.

In one embodiment, selecting one of the M gamma reference voltages includes:
Decoding the color signal to generate a gamma reference voltage selection signal, and connecting one of the selected M gamma reference voltages to an output node. Driving any one of the M switches corresponding to the M gamma reference voltages in response to a selection signal.

  In some embodiments, generating the data current may include driving a data current transistor connected to the output node using one of the selected M gamma reference voltages.

  In some embodiments, the method may further include limiting the data current using a clamp circuit.

  In some embodiments, generating the M gamma reference voltages based on each of the M gamma reference currents may include generating the M gamma reference voltages in response to each of the M gamma reference currents. To generate M current-voltage conversion circuits may be included.

  According to another embodiment of the present invention, a method of driving a data driver of a display device includes generating L gray scale reference currents, and M gammas from the L gray scale reference currents in response to a gamma signal. Selecting a reference current. Selecting one of the M gamma reference currents for each of the plurality of data lines in response to a color signal; and selecting one of the selected M gamma reference currents. Generating a data current in response. The method further includes driving the plurality of scan lines to select a plurality of pixels respectively determined by one of the plurality of data lines and one of the plurality of scan lines.

  A data driver of a display device according to another embodiment of the present invention includes a reference current generator that generates L gray scale reference currents corresponding to values other than zero gray levels, and the L data drivers in response to a gamma signal. A gamma selection module that selects M gamma reference currents from a plurality of gradation reference currents, a gamma voltage generation unit that generates a zero gradation level gamma reference voltage, and a selection from M gamma reference currents in response to a color signal And a data current generator for generating a data current in response to the one or zero gray level gamma reference voltage.

  In some embodiments, the gamma selection module includes a decoder that generates a gamma current selection signal in response to the gamma signal, and M gammas that respectively select M gamma reference currents in response to the gamma current selection signal. A selection switch.

In an embodiment, the reference current generator may include a current mirror composed of L transistors having different widths.
In some embodiments, the data current generator may further include M current-voltage conversion circuits that generate M additional gamma reference voltages based on each of the M gamma reference currents. A voltage that generates one of the data currents in response to any one of the gamma reference voltage selection unit that selects one signal from M + 1 gamma reference voltages in response and the selected M + 1 gamma reference voltages. -A current conversion circuit can be included.

  According to another embodiment of the present invention, a display device includes a reference current generator that generates L gray scale reference currents corresponding to values other than zero gray levels, and L gray scale references in response to a gamma signal. A gamma selection module that selects M gamma reference currents from the current, a gamma voltage generation unit that generates a zero gray level gamma reference voltage, and one selected from the selected M gamma reference currents in response to a color signal. Or a plurality of data current generators corresponding to a plurality of data lines, and one of the plurality of data lines and one of the plurality of scan lines. And a scan driver for driving the plurality of scan lines to select a plurality of pixels determined respectively.

  A data driver of a display device according to another embodiment of the present invention includes a reference current generator that generates L grayscale reference currents, and M grayscale reference currents in response to a gamma signal. A gamma selection module for selecting a gamma reference current; and a plurality of data current generators for generating a data current in response to one selected from the selected M gamma reference currents in response to a color signal. Including.

  In one embodiment, the gamma selection module includes a decoder that generates a gamma current selection signal in response to the color signal, and M number of gamma reference currents that respectively select the M gamma reference currents in response to the gamma current selection signal. A gamma selection switch.

  In an embodiment, the reference current generator may include a current mirror including L transistors having different widths for generating the L gray scale reference currents.

In an embodiment, the circuit further comprises M current-voltage conversion circuits for generating M gamma reference voltages based on each of the M gamma reference currents.
The data current generator is configured to select one of M gamma reference voltages in response to the color signal, and to respond to one of the selected M gamma reference voltages. A voltage-current conversion circuit for generating a data current.

  The gamma voltage selection unit may correspond to each of the M reference voltages, a decoder for generating a gamma reference voltage selection signal in response to the color signal, and in response to the gamma reference voltage selection signal. An M number of switches that connect one of the M number of gamma reference voltages to an output node may be included.

In an embodiment, the voltage-current conversion circuit may include a data current transistor connected at the output node.
In an exemplary embodiment, a clapping circuit connected between the data current transistor and an output reference terminal may be further included.

  According to another embodiment of the present invention, a display device includes a reference current generator for generating L gray scale reference currents, and M gamma reference currents from the L gray scale reference currents in response to a gamma signal. A gamma selection module to select, and a plurality of data current generators corresponding to a plurality of data lines and respectively generating a data current in response to one selected from the M gamma reference currents in response to a color signal And driving the plurality of scan lines to select a plurality of pixels respectively determined by one of the plurality of data lines and one of the plurality of scan lines.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same components in the drawings, and duplicate descriptions for the same components are omitted.

  One embodiment of the present invention stems from the ability to select 8-bit tone color data using a 6-bit color data signal without the need for a look-up table. As a result, the area of the chip is not increased, and a finer gradation expression such as using an 8-bit gradation color signal to drive the display device is enabled.

  Referring to FIG. 2, the data driver circuit 300 according to an exemplary embodiment of the present invention includes a plurality of data current generators 500 that generate a data current (IDATA) in response to the grayscale data 355 and the grayscale gamma voltage 453. . The data driver circuit 300 includes a gamma setting unit 400 that selects a plurality of gamma reference currents in response to a gamma selection signal. The gamma reference current is converted into a gradation gamma reference voltage. The gray scale gamma reference voltage can be selected as an output in response to a color signal.

As shown in FIG. 2, the data driver circuit 300 includes a controller 310 that receives input of Q-bit color data 351 and a gamma setting command 353 from the external controller 350. When reproducing the 2 ¹⁸ color, red / green / blue color can be used in the 6-bit color signal 351, to reproduce the ²²⁴ color, the use of the red / green / blue color 8-bit color signal 351 Can do.

The controller 310 uses the gamma setting command 353 to generate the gamma selection signal 312, and the gamma selection signal 312 is provided to the gamma setting unit 400. For example, the gamma setting command 353 can be used to select a gamma value selected in advance by the user. The gamma selection signal 312 may be composed of N bits to select one of 2 ^N possible gamma values.

  The gamma setting unit 400 includes a gamma selection circuit 410, a current-voltage conversion circuit 440, and a gradation gamma voltage generation unit 450. The gamma selection circuit 410 generates L gradation reference currents 422 and selects M of the L gradation reference currents as the gamma reference currents 432 in response to the gamma selection signal 312. For example, L may be 255 when the gradation reference current has an 8-bit gradation level.

The data driver 300 provides K gamma curves, each gamma curve having M gamma reference currents corresponding to other gray levels. That is, the data driver 300 provides K gamma curve groups. For example, when K is 10, there are 10 gamma curves, and one gamma reference current group is selected in response to the gamma selection signal 312. Therefore, at least 4 bits (where 2 ^N > K) are used for the gamma selection signal 312. In one embodiment, L has a value greater than M to generate a denser M number of gray scale reference currents. For example, when L is 255, a gradation reference current corresponding to a total of 256 gradation levels can be provided, and when L is 511, a gradation reference current corresponding to a total of 512 gradation levels is provided. be able to.

  The gamma setting unit 400 includes a gamma selection circuit 410, a current-voltage conversion circuit 440, and a gradation gamma voltage generation unit 450. The current-voltage conversion circuit 440 converts the M gamma reference currents 432 output from the gamma selection circuit 410 into M gradation gamma voltages 442. The gray level gamma voltage generator 450 generates M + 1 gray level gamma voltages 453 in response to the M gamma voltages 442. The M + 1 gray scale gamma voltages may be based on the M gamma voltages 442 and a zero gray level gamma reference voltage. The data current generator 500 selects one of the M + 1 grayscale gamma voltages in response to the video / color data signal 355, and generates a data current (IDATA) in response to the selected grayscale gamma voltage. generate.

  FIG. 3 is a block diagram illustrating a gamma setting unit 400 according to an embodiment of the present invention. The gamma setting unit 400 includes a gamma selection circuit 410, a current-voltage conversion circuit 440, and a gradation gamma voltage generation unit 450. The gamma selection circuit 410 includes a reference current source generator 411, a reference current switch 412, a reference current generator 420, and a gamma selector 430, which are connected as shown in the drawing. The reference current source generation unit 411 generates a reference current (IREF) and supplies the reference current generation unit 420 with the reference current (IREF). In an exemplary embodiment, the gamma setting unit 400 may further include a gray level reference voltage generator 401 that provides an R, G, B gray level reference voltage or a common gray level reference voltage. When the gradation reference voltage is provided independently for each of R, G, and B, a reference current switch 412 is interposed between the reference current source generator 411 and the gradation reference current generator 420. Thus, a gradation reference voltage corresponding to one of R, G, and B can be selected. As shown in FIG. 3, the gray scale reference voltage can be generated using a static voltage (VREG) and a voltage distribution circuit. The gray scale reference current generator 420 generates L gray scale reference currents 422 in response to the reference current (IREF). The gamma selection unit 430 outputs M gamma reference currents 432 in response to the L gradation reference currents 422 and the N-bit gamma selection signal 312. The current-voltage conversion circuit 440 generates M gamma voltages 442 in response to the M gamma reference currents 432. In one embodiment, the current-voltage conversion circuit 440 may include M MOS transistors 441 configured to operate in a saturation mode and have a gate-source voltage determined by a drain current. The gray level gamma voltage generator 450 receives M number of gamma voltages 442 and zero gray level gamma voltage 443 output from the current / voltage conversion circuit 440 for R, G, and B, respectively. M + 1 gray-scale gamma voltages 453 are generated using a sir (MUX) and a voltage buffer. The zero gray level gamma voltage may be a ground voltage or a common reference voltage.

FIG. 4 is a diagram schematically illustrating a reference current generator 420 according to an embodiment of the present invention. The reference current generator 420 may be implemented as a current mirror including an input transistor 421 and L mirror transistors (PM1 to PM255). According to various embodiments of the present invention, the mirroring transistor may be implemented as a PMOS or NMOS transistor. The current (I ₁ ) is a current corresponding to a stage brighter by one level than the darkest gradation level (0 gray level), and the current (I ₂₅₅ ) is a current corresponding to the brightest gradation level. In order to generate different currents, the mirroring transistors PM1 to PM255 may have different widths.

  The graph of FIG. 5 illustrates a gamma correction curve in the case of having 256 levels of gradation reference current (L = 255), 64 levels of gamma reference current (M = 63), and 10 gamma curves (K = 10). It is a thing. In the graph, the gamma value increases by 0.4 to 0.2. In this way, a substantially 8-bit gradation level can be expressed approximately by a 6-bit color data signal. That is, by selecting an 8-bit gradation level based on a 6-bit color data signal, a more detailed gradation expression can be achieved. Table 1 below shows the gradation reference current corresponding to the 28th gradation level.

図６は、本発明の一実施例によるガンマ選択部４３０を概略的に示す。前記ガンマ選択部４３０は、スイッチ回路４３５を含み、前記スイッチ回路４３５は、Ｍが６３である場合、６３個のスイッチブロック（４３３−１〜４３３−６３）を含む。前記各スイッチ段はＫが１０である場合、１０個のスイッチ（ＳＷ０〜ＳＷ９）を含むことができる。前記スイッチ（ＳＷ０〜ＳＷ９）は、基準電流発生部４２０のミラリングトランジスタ（ＰＭ１〜ＰＭ２５５）のうち、いずれか一つに連結されている。Ｎビットのガンマ選択信号３１２によっていずれか一つのスイッチのみオンされ、他のスイッチはオフされるように制御される。２８番目の階調レベルに該当するスイッチブロック（４３３−２８）内の１０個のスイッチ（ＳＷ０〜ＳＷ９）は、ミラリングトランジスタＰＭ１８０、ＰＭ１５８、ＰＭ１３６、ＰＭ１２０、ＰＭ１０５、ＰＭ９２、ＰＭ７８、ＰＭ６７、ＰＭ５９、及びＰＭ５０とそれぞれ連結することができる。もし選択されたガンマが２．０（９番目のガンマ）であると、ガンマ選択信号（ＳＥＬ８）が入力され、９番目のスイッチ（ＳＷ８）がオンされ、５９番目の階調基準電流（Ｉ５９）が前記２８番目の階調レベルに相応するガンマ電流（ＩＧ２８）に出力される。もし選択されたガンマが２．０（９番目のガンマ）であると、ガンマ選択信号（ＳＥＬ８）に応答する６３個のスイッチがオンされ、６３個のガンマ電流（ＩＧ１〜ＩＧ６３）が出力される。前記６３個のガンマ電流をガンマ電流群といい、ガンマ電流群は、前記Ｎビットガンマ選択信号３１２によって選択される。

FIG. 6 schematically illustrates a gamma selection unit 430 according to an embodiment of the present invention. The gamma selection unit 430 includes a switch circuit 435. When the M is 63, the switch circuit 435 includes 63 switch blocks (433-1 to 433-63). Each switch stage may include 10 switches (SW0 to SW9) when K is 10. The switches SW0 to SW9 are connected to any one of the mirroring transistors PM1 to PM255 of the reference current generator 420. Only one of the switches is turned on by the N-bit gamma selection signal 312 and the other switches are controlled to be turned off. Ten switches (SW0 to SW9) in the switch block (433-28) corresponding to the 28th gradation level are mirroring transistors PM180, PM158, PM136, PM120, PM105, PM92, PM78, PM67, PM59, and Each can be connected to PM50. If the selected gamma is 2.0 (9th gamma), the gamma selection signal (SEL8) is input, the 9th switch (SW8) is turned on, and the 59th gradation reference current (I59). Is output to a gamma current (IG28) corresponding to the 28th gradation level. If the selected gamma is 2.0 (9th gamma), 63 switches responding to the gamma selection signal (SEL8) are turned on, and 63 gamma currents (IG1 to IG63) are output. . The 63 gamma currents are referred to as a gamma current group, and the gamma current group is selected by the N-bit gamma selection signal 312.

  FIG. 7 is a block diagram illustrating a gamma selection unit 430 according to an embodiment of the present invention. The gamma selection unit 430 includes a decoder 431 and a switch circuit 433. The decoder 431 decodes the gamma selection signal 312 and outputs a switch selection signal 314. In one embodiment, the decoder 431 may be implemented as a circuit such as a dimultiflexer. The switches (SW0 to SW9) are connected to the M mirror transistors. If the I-th gamma current group is selected, the corresponding switch is turned on, and the current corresponding to the I-th gun I-th gamma current group is output at a time. In this embodiment, no gamma reference current corresponding to the zero gray level is generated.

FIG. 8 is a block diagram of a data driver circuit 300a according to one embodiment of the present invention.
In the data driver circuit 300a of FIG. 8, the gamma selection circuit 410a, the reference current generation unit 420a, and the gamma selection unit 430a are involved in generating L + 1 gradation reference currents 422a and M + 1 gamma reference currents 432a. Except for this, the operation is similar to that of the data driver circuit 300 of FIGS. The L + 1 gray scale reference currents 422a include a current corresponding to a zero gray scale reference level, and the M + 1 gamma reference currents 432a include a current corresponding to a zero gray scale reference level. Therefore, when L is 265, 256 gradation reference currents 422a are generated, and when M is 63, 64 gamma reference currents 432a are generated.

  FIG. 9 is a block diagram of the gamma selection unit 430a according to an embodiment of the present invention. The gamma selection unit 430a has 63 switch blocks (433-1 to 433-63) except that the switch circuit 435a includes 64 switch blocks (433-1 to 433-64). This is similar to the gamma selection unit 430. The added switch part corresponds to the zero reference level.

  FIG. 10 is a diagram schematically showing the data current output unit 500. The data current output unit 500 includes a gray level gamma voltage selection unit 510, a voltage-current conversion unit 520, and an output node 540, which are connected as shown in the drawing. The gradation gamma voltage selection unit 510 includes a decoder 511 and M + 1 switches 512. The decoder 511 receives the Q-bit gradation data 355 from the controller 310. The switch 512 selects one of the M + 1 gradation gamma voltages 453 in response to the gradation data color signal 355. The voltage-current conversion unit 520 is a driving transistor whose drain current is adjusted by the output of the gradation gamma voltage selection unit 510. The drain current is output as a data current (IDATA). According to an exemplary embodiment, the voltage-current converter 520 may be connected to a clamp circuit 530 for limiting a data current (IDATA) current level to a data line based on a clamp signal.

  FIG. 11 is a block diagram of a display device including a data driver according to an embodiment of the present invention. The display device includes a pixel region 100, a scan driver 200, and a data driver circuit 300. The data driver circuit 300 may be implemented as described above with reference to FIGS. The pixel region 100 may include a plurality of OLED pixels 15. The scan driver 200 provides a scan signal to the scan lines S1 to SN. The data driver 300 provides the grayscale driving currents (D1 to DM) as described above.

  Therefore, unlike a conventional gamma correction method using a look-up table, an additional circuit by adding dummy bits for gamma correction is not required, and thus a DAC circuit connected to an output channel is simplified. Overall, the chip size of the data driver is reduced. In particular, when the number of output channels connected to the data line increases due to an increase in the size and resolution of the display device, an increase in the chip size of the data driver can be prevented.

  As described above, the embodiments of the present invention have been described in detail. However, the present invention is not limited to these embodiments, and any person who has ordinary knowledge in the technical field to which the present invention belongs can be used without departing from the spirit and spirit of the present invention. The present invention can be modified or changed.

It is a block diagram of a data driver circuit of a display device for conventional gamma correction. 1 is a block diagram of a data driver circuit according to an embodiment of the present invention. FIG. FIG. 3 is a block diagram of a gamma setting unit of FIG. 2 according to an embodiment of the present invention. FIG. 4 is a schematic diagram of a reference current generator of FIG. 3 according to an embodiment of the present invention. 7 is a graph illustrating a gamma correction curve according to an embodiment of the present invention having 256 gray scale reference currents, 64 gamma reference currents, and 10 gamma curves. FIG. 4 is a schematic diagram of a gamma selection unit of FIG. 3 according to an embodiment of the present invention. FIG. 4 is a block diagram of a gamma selection unit of FIG. 3 according to an embodiment of the present invention. FIG. 5 is a block diagram of a data driver circuit according to another embodiment of the present invention. FIG. 9 is a block diagram of a gamma selection unit of FIG. 8 according to another embodiment of the present invention. FIG. 9 is a schematic diagram of the data current generator of FIGS. 3 and 8 according to an embodiment of the present invention. 1 is a block diagram of a display device including a data driver according to an embodiment of the present invention.

Explanation of symbols

300 Data driver circuit 310 Control unit 400 Gamma setting unit 410, 410a Gamma selection module 420, 420a Reference current generation unit 430, 430a Gamma selection unit 440 Current-voltage conversion circuit 450, 510 Grayscale gamma voltage generation unit 433-1, 433 -2, ..., 433-63 Switch 435 Switch block 500 Data current generator

Claims (30)

Generating L gray scale reference currents corresponding to values that are not zero gray levels;
Selecting M gamma reference currents from the L gradation reference currents in response to a gamma signal;
Generating a zero gradation level gamma reference voltage;
In response to a color signal, selecting one of the M gray level reference currents or selecting the zero gray level gamma reference voltage;
Generating a data current in response to one or zero gray level gamma reference voltage from the selected M gray scale reference currents;
Selecting one of the M gray scale reference currents or selecting a zero gray level gamma reference voltage;
Generating M gamma reference voltages based on each of the M gamma reference currents;
Selecting one of M + 1 gamma reference voltages in response to the color signal;
Generating the data current comprises:
A data driver driving method of a display device, wherein the data current is generated in response to any one of the selected M + 1 gamma reference voltages, and L is a value greater than M. The step of selecting the M gamma reference currents includes:
Decoding the gamma signal to generate a gamma current selection signal;
2. The display device data driver driving method according to claim 1, further comprising: driving M number of gamma selection switches that respectively select the M number of gamma reference currents in response to the gamma current selection signal. Method. The step of generating the L gradation reference currents includes:
2. The method of driving a driver of a display device according to claim 1, wherein a current mirror composed of L transistors having different widths is used. Selecting one of the M + 1 gamma reference voltages comprises:
Decoding the color signal to generate a gamma reference voltage selection signal;
In order to connect one of the selected M + 1 gamma reference voltages to an output node, M + 1 switches corresponding to the M + 1 gamma reference voltages in response to the gamma reference voltage selection signal, respectively. The method for driving a data driver of a display device according to claim 1, further comprising: driving any one of them. Generating the data current comprises:
5. The method of claim 4, further comprising driving a data current transistor connected to the output node using one of the selected M + 1 gamma reference voltages. .   6. The method of claim 5, further comprising the step of limiting the data current using a clamp circuit. Generating M gamma reference voltages based on each of the M gamma reference currents;
2. Using M current-voltage conversion circuits to additionally generate the M gamma reference voltages in response to each of the M gamma reference currents. Data driver driving method. Generating L gray scale reference currents corresponding to values that are not zero gray levels;
Selecting M gamma reference currents from the L gradation reference currents in response to a gamma signal;
Generating a zero gradation level gamma reference voltage;
Selecting one of the M gamma reference currents or the zero gray level gamma reference voltage in response to a color signal for each of a plurality of data lines;
Generating a data current in response to one or the zero gray level gamma reference voltage from the selected M gamma reference currents for each of the plurality of data lines;
Driving the plurality of scan lines to select a plurality of pixels respectively determined by one from the plurality of data lines and one from the plurality of scan lines;
Selecting one of the M gray scale reference currents or selecting a zero gray level gamma reference voltage;
Generating M gamma reference voltages based on each of the M gamma reference currents;
Selecting one of M + 1 gamma reference voltages in response to the color signal;
Generating the data current comprises:
A data driver driving method of a display device, wherein the data current is generated in response to any one of the selected M + 1 gamma reference voltages, and L is a value greater than M. Generating L gray scale reference currents;
Selecting M gamma reference currents from the L gradation reference currents in response to a gamma signal;
Selecting one of the M gamma reference currents in response to a color signal;
Generating a data current in response to any one of the selected M gray scale reference currents;
Selecting one of the M gray scale reference currents;
Generating M gamma reference voltages based on each of the M gamma reference currents;
Selecting one of the M gamma reference voltages in response to the color signal;
Generating the data current comprises:
A data driver for a display device, comprising: generating the data current in response to any one of the selected M gamma reference voltages, wherein L is a value greater than M Driving method. The step of selecting the M gamma reference currents includes:
Decoding the gamma signal to generate a gamma current selection signal;
10. The display device data driver driving method according to claim 9, further comprising: driving M number of gamma selection switches that respectively select the M number of gamma reference currents in response to the gamma current selection signal. Method. The step of generating the L gradation reference currents includes:
10. The display device data driver driving method according to claim 9, further comprising using a current mirror composed of L transistors having different widths. Selecting one of the M gamma reference voltages comprises:
Decoding the color signal to generate a gamma reference voltage selection signal;
In order to connect one of the selected M gamma reference voltages to an output node, M switches corresponding respectively to the M gamma reference voltages in response to the gamma reference voltage selection signal. The method for driving a data driver of a display device according to claim 9, further comprising: driving any one of them. Generating the data current comprises:
13. The data driver of a display device according to claim 12, further comprising: driving a data current transistor connected to the output node using one of the selected M gamma reference voltages. Driving method.   The method of claim 13, further comprising limiting the data current using a clamp circuit. Generating M additional gamma reference voltages based on each of the M gamma reference currents;
10. Using M current-voltage conversion circuits to generate the M gamma reference voltages in response to each of the M gamma reference currents. Data driver driving method for the display device of FIG. Generating L gray scale reference currents;
Selecting M gamma reference currents from the L gradation reference currents in response to a gamma signal;
Selecting one of the M gamma reference currents for each of a plurality of data lines in response to a color signal;
Generating a data current in response to any one of the selected M gamma reference currents for each of the plurality of data lines;
Driving a plurality of scan lines to select a plurality of pixels respectively determined by one from the plurality of data lines and one from the plurality of scan lines;
Selecting one of the M gray scale reference currents;
Generating M gamma reference voltages based on each of the M gamma reference currents;
Selecting one of the M gamma reference voltages in response to the color signal;
Generating the data current comprises:
A data driver for a display device, comprising: generating the data current in response to any one of the selected M gamma reference voltages, wherein L is a value greater than M Driving method. A reference current generator for generating L gray scale reference currents corresponding to values other than zero gray levels;
A gamma selection module for selecting M gamma reference currents from the L gradation reference currents in response to a gamma signal;
A gamma voltage generator for generating a zero gradation level gamma reference voltage;
A data current generator for generating a data current in response to one or zero gray level gamma reference voltage selected from M gamma reference currents in response to a color signal;
Including M current-voltage conversion circuits for generating M gamma reference voltages based on each of the M gamma reference currents;
The data current generator is responsive to the color signal to select one of M + 1 gamma reference voltages and one of the selected M + 1 gamma reference voltages. A data driver for a display device, comprising a voltage-current conversion circuit for generating the data current, wherein L is a value larger than M. The gamma selection module is
A decoder for generating a gamma current selection signal in response to the gamma signal;
18. The data driver of a display device according to claim 17, further comprising: M gamma selection switches that respectively select M gamma reference currents in response to the gamma current selection signal.   18. The data driver of a display device according to claim 17, wherein the reference current generating unit includes a current mirror composed of L transistors having different widths. The gamma reference voltage selector is
A decoder for generating a gamma reference voltage selection signal in response to the color signal;
M + 1 switches each corresponding to the M + 1 gamma reference voltages and linking one of the M + 1 gamma reference voltages to an output node in response to the gamma reference voltage selection signal. 18. A data driver for a display device according to claim 17. The voltage-current conversion circuit includes:
21. The data driver of a display device according to claim 20, further comprising a data current transistor connected at the output node.   The data driver of claim 21, further comprising a clamp circuit connected between the data current transistor and an output reference terminal. A reference current generator for generating L gradation reference currents corresponding to values other than zero gradation levels;
A gamma selection module that selects M gamma reference currents from L grayscale reference currents in response to a gamma signal;
A gamma voltage generator for generating a zero gradation level gamma reference voltage;
A plurality of data current generators corresponding to a plurality of data lines, each generating a data current corresponding to one or zero gray level reference voltage from the selected M gamma reference currents in response to a color signal; ,
A scan driver for driving the plurality of scan lines to select a plurality of pixels respectively determined by one from the plurality of data lines and one from the plurality of scan lines;
Including M current-voltage conversion circuits for generating M gamma reference voltages based on each of the M gamma reference currents;
The data current generator is responsive to the color signal to select one of M + 1 gamma reference voltages and one of the selected M + 1 gamma reference voltages. A display device comprising a voltage-current conversion circuit for generating the data current, wherein L is a value larger than M. A reference current generator for generating L gradation reference currents;
A gamma selection module that selects M gamma reference currents from L grayscale reference currents in response to a gamma signal;
A plurality of data current generators for generating a data current responsive to one selected from the M gamma reference currents in response to the color signal;
M current-voltage conversion circuits for generating M gamma reference voltages based on each of the M gamma reference currents,
The data current generator is
A gamma voltage selector that selects one of M gamma reference voltages in response to the color signal;
A voltage-current conversion circuit for generating the data current in response to one of the selected M gamma reference voltages, wherein L is a value greater than M. Data driver. The gamma selection module is
A decoder for generating a gamma current selection signal in response to the color signal;
25. The data driver of the display device according to claim 24, further comprising: M gamma selection switches that respectively select the M gamma reference currents in response to the gamma current selection signal. The reference current generator is
25. The data driver of a display device according to claim 24, further comprising: a current mirror composed of L transistors having different widths for generating each of the L gray scale reference currents. The gamma voltage selection unit includes:
A decoder for generating a gamma reference voltage selection signal in response to the color signal;
Each of the M reference voltages corresponds to the M reference voltages, and includes M switches for connecting any one of the M gamma reference voltages to an output node in response to the gamma reference voltage selection signal. 25. A data driver for a display device according to claim 24. The voltage-current conversion circuit includes:
28. The data driver of a display device according to claim 27, further comprising a data current transistor connected at the output node.   30. The data driver of a display device according to claim 28, further comprising a clap circuit connected between the data current transistor and an output reference terminal. A reference current generator for generating L gradation reference currents;
A gamma selection module that selects M gamma reference currents from L grayscale reference currents in response to a gamma signal;
A plurality of data current generators corresponding to a plurality of data lines, each generating a data current in response to one selected from the M gamma reference currents in response to a color signal;
A scan driver for driving the plurality of scan lines to select a plurality of pixels respectively determined by one of the plurality of data lines and one of the plurality of scan lines;
M current-voltage conversion circuits for generating M gamma reference voltages based on each of the M gamma reference currents,
The data current generator is
A gamma voltage selector that selects one of M gamma reference voltages in response to the color signal;
And a voltage-current conversion circuit for generating the data current in response to one of the selected M gamma reference voltages, wherein L is a value greater than M.

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