KR101174985B1 - Data driver of display apparatus and method for operating data driver of display apparatus - Google Patents

Data driver of display apparatus and method for operating data driver of display apparatus Download PDF

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KR101174985B1
KR101174985B1 KR1020100041484A KR20100041484A KR101174985B1 KR 101174985 B1 KR101174985 B1 KR 101174985B1 KR 1020100041484 A KR1020100041484 A KR 1020100041484A KR 20100041484 A KR20100041484 A KR 20100041484A KR 101174985 B1 KR101174985 B1 KR 101174985B1
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South Korea
Prior art keywords
memory unit
data driver
reference voltage
resistor string
dac
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KR1020100041484A
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Korean (ko)
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KR20110121952A (en
Inventor
최병덕
김태욱
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한양대학교 산학협력단
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Priority to PCT/KR2010/002815 priority Critical patent/WO2011138978A1/en
Priority to KR1020100041484A priority patent/KR101174985B1/en
Publication of KR20110121952A publication Critical patent/KR20110121952A/en
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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3685—Details of drivers for data electrodes
    • G09G3/3688—Details of drivers for data electrodes suitable for active matrices only
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
    • G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • G09G3/3208—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
    • G09G3/3275—Details of drivers for data electrodes
    • G09G3/3291—Details of drivers for data electrodes in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0264—Details of driving circuits
    • G09G2310/027—Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/02—Improving the quality of display appearance
    • G09G2320/0271—Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
    • G09G2320/0276—Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Liquid Crystal Display Device Control (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)

Abstract

A data driver of a display device is provided. The data driver may include a plurality of resistor strings designed to match gamma characteristics of R, G, and B, respectively. The switch unit of the data driver selects any one of the plurality of resistance strings and transmits the same to the decoder.

Figure R1020100041484

Description

DATA DRIVER OF DISPLAY APPARATUS AND METHOD FOR OPERATING DATA DRIVER OF DISPLAY APPARATUS}

Some embodiments of the invention relate to a display device, and more particularly to an implementation of a data driver and a digital to analog converter (DAC) of the display device.

Recently, display devices have been implemented using flat panels such as TFT LCDs and OLEDs.

Such a flat panel includes a pixel array composed of a plurality of rows and columns. In this case, the data driver transmits an analog voltage (or current, or the same) to each pixel of a row selected by the scan driver, and displays light at each pixel of the row.

In this process, the analog voltage is transferred from the digital data by the DAC in the data driver.

There are several known methods for implementing a DAC, one of which uses a resistor string coupled between a high level reference voltage (VH) and a low level reference voltage (VL).

In this case, a decoder that receives a digital value from logic (hereinafter, a decoder may be used in combination with a digital to analog converter) may have a plurality of node voltages between resistance strings according to the digital value. Any one of them is selected and passed to the pixel.

However, the display device has a different gamma characteristic for each of red, green, and blue. Therefore, it is necessary to adjust the reference voltage levels of Red, Green, and Blue differently for white balance.

In the DAC implementation of the data driver, a data driver and a method of driving the data driver that can reduce the number of reference lines are provided.

In addition, a data driver and a method of driving the data driver are provided to reduce the number of reference lines in implementing a gray voltage generator.

According to an aspect of the present invention, an input terminal for receiving a reference voltage level from a plurality of resistance strings, a switch unit for selecting any one of the plurality of resistance strings according to a control signal, and a reference of the resistance string selected by the switch unit A data driver is provided that includes an output terminal for transmitting a voltage level to a decoder.

The data driver may further include a controller for transmitting a control signal to the switch unit.

The switch unit may sequentially select the plurality of resistor strings according to the control signal.

According to an embodiment of the present invention, at least one of the plurality of resistor strings is associated with a reference voltage level according to a gamma characteristic of a red color, and at least one other is associated with a reference voltage level according to a gamma characteristic of a green color, Another at least one is related to the reference voltage level according to the gamma characteristic of the blue color.

In this case, the switch unit may include a resistance string associated with a reference voltage level according to the gamma characteristic of the red color, a resistance string associated with a reference voltage level according to the gamma characteristic of the green color, and a gamma of the blue color according to the control signal. The resistance string associated with the reference voltage level according to the characteristic can be selected sequentially and repeatedly.

According to another aspect of the invention, the first resistor string to generate a reference voltage level, at least one DAC for transmitting at least a portion of the reference voltage level generated by the first resistor string to the second resistor string, and the at least A data driver is provided that includes a memory portion for supplying digital data to select a reference voltage level that one DAC delivers to a second resistor string.

The memory unit may include a first memory unit storing digital data associated with a reference voltage level based on a gamma characteristic of red color, a second memory unit storing digital data associated with a reference voltage level based on a gamma characteristic of green color; And a third memory unit configured to store digital data associated with a reference voltage level according to a gamma characteristic of a blue color.

In this case, the data driver may further include a switch unit which selects one of the first memory unit, the second memory unit, and the third memory unit to transfer digital data of the selected memory unit to the at least one DAC. Can be.

The data driver may further include a controller configured to transmit a control signal to the switch unit so that the switch unit selects one of the first memory unit, the second memory unit, and the third memory unit.

According to an embodiment of the present invention, the control unit transmits the control signal such that the switch unit sequentially selects the first memory unit, the second memory unit, and the third memory unit.

According to still another aspect of the present invention, an input terminal of a data driver receives a reference voltage level from a plurality of resistor strings, a switch unit of the data driver selects any one of the received reference voltage levels, and A method of operating a data driver is provided comprising an output terminal of a data driver transferring the selected reference voltage level to a decoder of the data driver.

According to another aspect of the present invention, at least one DAC of the data driver receives digital data associated with a reference voltage level according to a gamma characteristic of any one of red, green, and blue colors from a memory unit of the data driver. And supplying at least one of the reference voltage levels of the first resistor string of the data driver to the second resistor string by the at least one DAC using the digital data. This is provided.

In the DAC implementation of the data driver, the number of reference lines is greatly reduced, which significantly reduces the circuit volume.

In addition, the circuit volume is reduced by reducing the number of resistor strings and the number of reference lines in implementing a gray voltage generator.

 The distortion of the pixel value is reduced.

1 illustrates a data driver according to an embodiment of the present invention.
2 illustrates a data driver according to an embodiment of the present invention.
3 illustrates an exemplary waveform of a control signal input to a data driver according to the embodiment of FIGS. 1 and 2.
4 illustrates a data driver according to an embodiment of the present invention.
5 illustrates an exemplary waveform of a control signal input to a data driver according to an embodiment of the present invention.
6 is a flowchart illustrating a method of operating a data driver according to an embodiment of the present invention.
7 is a flowchart illustrating a method of operating a data driver according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited or limited by the embodiments. Like reference symbols in the drawings denote like elements.

1 shows a data driver 100 according to an embodiment of the invention.

The data driver 100 of the display apparatus according to an exemplary embodiment receives the reference voltages from the resistor strings 101, 102, and 103 and selects one of the resistor strings 101, 102, and 103. The reference voltage of the selected resistor string is transferred to the decoders 105 and 106.

Typically, the panel portion (not shown) of the display device is composed of elements such as organic light emitting diodes (hereinafter referred to as "OLED") and TFT LCD (Thin film Transistor Liquid Crystal Display). In addition, OLEDs include Active Matrix Organic Light Emitting Diodes (AMOLEDs) and Passive Matrix Organic Light Emitting Diodes (PMOLEDs).

Therefore, even if not mentioned below, the data driver of the present invention should not be interpreted as for some kind of pixel element, and those of ordinary skill in the art will not change the spirit of the present invention. It will be apparent that various modifications and applications of the scope are not excluded from the scope of the present invention.

As described above, the pixel elements constituting the panel unit may be selected from various kinds, and these pixel elements have different gamma characteristic curves for red, green, and blue, which are three primary colors of light.

That is, even though the same voltage is applied to the R (Red), G (Green), and B (Blue) pixels, the brightness of the R, G, and B light displayed through each pixel has a slight difference. balance issues.

In addition, the sensitivity of human eyes to changes in the brightness of the light is non-linear, and the brightness of the pixel elements of the display panel is adjusted to the human eye by adjusting the nonlinearity. It can be a highly visible panel.

In order to correct the white balance problem of the display panel pixel element and / or the nonlinear characteristics of the human eye, the reference voltage levels input to the decoder unit 105, 106, etc. of the display device are different for R, G, and B. It needs to be set, and also needs to be adjusted to fit the gamma characteristic curve.

1 is a configuration for varying the reference voltages input to the decoder unit 105, 106, etc. to solve the white balance problem associated with the R. G and B colors as described above.

According to the conventional conventional method, the resistance string 101 for the R color, the resistance string 102 for the G color, and the resistance string 103 for the B color may be separately implemented.

In the following description, a case in which the voltage level to be decoded through the DAC of the data driver is 64, that is, the digital data of a pixel input from the logic 104 is 6 bits will be described. However, this example is arbitrarily set for convenience of description, and may be changed to other settings without departing from the spirit of the present invention.

In this embodiment, the resistance string 101 divides between the high reference voltage VHR and the low reference voltage VLR into 64 reference voltage levels to suit the characteristics of the Red pixel.

The resistance string 102 divides between the high reference voltage VHG and the low reference voltage VLG into 64 reference voltage levels to suit the characteristics of the green pixel, and the resistance string 103 between the high reference voltage VHB and the low reference voltage VLB. Is divided into 64 reference voltage levels to suit the characteristics of the blue pixel.

In this case, according to the conventional method, the nodes R1, R2,... Of each of the 64 reference voltages generated from the resistance string 101 without the configuration of the data driver 100 which is part of the configuration of the data driver. ..., R64), nodes of each of the other 64 reference voltages generated from the resistance string 102, G1, G2,..., G64, and another 64 reference voltages generated from the resistance string 103. Each node (B1, B2, ..., B64) had to be connected to reference lines (Ref 1, Ref 2, ...) to the decoder. As a result, there are up to 192 reference lines (= 64 * 3), which increases the circuit volume for the data driver implementation.

Of course, the reference line may be shared for reference voltage levels having some common values, but the reference voltages corresponding to the R, G, and B characteristics are not all delivered to the decoder while maintaining the 64 reference lines.

However, according to the exemplary embodiment of the present invention, the SR switches, the SG switches, and the SB switches in the switch unit 130 are sequentially and periodically selected according to the control signal of the controller 120.

When the SR switches are selected, the reference voltages of the nodes R1, R2,..., And R64 of the resistor string 101 are transmitted through the input terminal 110 and the output terminal 140, and the reference line Ref 1 , Ref 2, ..., Ref 64) to the decoders 105, 106, and the like.

In this case, the decoder 105, 106, etc. decodes the 6 bit digital data transferred from the logic 104, so that one of the reference voltages of the nodes R1, R2, ..., R64 of the resistor string 101 is decoded. Is passed through a buffer (107, 108, etc.) to a pixel array (not shown).

When the SG switches are selected, the reference voltages of the nodes G1, G2,..., G64 of the resistor string 102 are transmitted through the input terminal 110 and the output terminal 140, and the reference line ( Ref 1, Ref 2, ..., Ref 64) to the decoder 105, 106, and the like.

In this case, the decoder 105, 106, etc., decodes the 6 bit digital data transferred from the logic 104, so that one of the reference voltages of the nodes G1, G2,..., G64 of the resistor string 102 is present. Is passed through a buffer (107, 108, etc.) to a pixel array (not shown).

Similarly, when the SB switches are selected, the reference voltages of the nodes B1, B2, ..., B64 of the resistor string 103 are transmitted through the input terminal 110 and the output terminal 140, so that the reference line ( Ref 1, Ref 2, ..., Ref 64) to the decoder 105, 106, and the like.

In this case, the decoder 105, 106, etc. decodes the 6 bit digital data transferred from the logic 104, so that one of the reference voltages of the nodes B1, B2, ..., B64 of the resistance string 103 is present. Is passed through a buffer (107, 108, etc.) to a pixel array (not shown).

Then again SR switches are selected, and in this way the SR switches, SG switches, and SB switches are sequentially and repeatedly selected to selectively select reference voltage levels (up to 192) even if only 64 reference lines are placed. To the decoders 15, 106 and the like.

Thus, the number of reference lines can be greatly reduced so that the overall volume of the data driver circuit can be reduced.

Meanwhile, in the above-described embodiment, it is assumed that the pixel arrays are arranged in the order of the R column, the G column, and the B column, but the order of R, G, and B is not limited within the scope of the present invention. Any amount can be changed. In addition, the configuration in the switch unit 130 may also be changed to match the characteristics of a particular pixel element.

In addition, the number or shape of the resistance strings 101 to 103 corresponding to each of R, G, and B may also be variously changed within a range without departing from the spirit of the present invention.

Meanwhile, the controller 120 may be arranged in a separate configuration from the logic 104, but according to another embodiment of the present invention, a timing controller (not shown) of the logic 104 and / or the display device may be provided. It may also be implemented by).

Accordingly, the description of some embodiments of the invention should not be construed as excluding implementation by other embodiments without departing from the spirit of the invention.

2 illustrates a data driver according to an embodiment of the present invention.

According to one embodiment of the invention, the reference voltages delivered to the decoders 105, 106, etc., are delivered to the pixel array 220 through the buffers 107, 108, etc. In this case, the pixel array 220 may be configured in the order of an R column, a G column, a B column, an R column, ..., and the switch unit 210 stores these columns in R, G, B, R, Select in order of G, B, R, ...

This arrangement implements the RGBRGB ... order display.

Meanwhile, according to an embodiment of the present invention, the data driver 100 implementing such a sequential (time division) color display may be adopted in a small display device. For example, it can be adopted in a small display panel such as a head mount display.

Of course, the application of this data driver 100 should not be construed as limited to some embodiments.

An example of a control signal transmitted to the switch unit 130 and / or the switch unit 210 by the controller 120 to control the operation of the data driver of FIGS. 1 and 2 is illustrated with reference to FIG. 3.

3 illustrates an exemplary waveform of a control signal input to a data driver according to the embodiment of FIGS. 1 and 2.

When the SR switches of FIG. 1 are turned on, the reference voltages of the resistor string 101 are transferred to the reference lines Ref 1, Ref 2,..., Ref 64 through the SR switches. The voltages are delivered to the decoders 105, 106, and the like.

Then, the SD0 switches of the switch unit 210 of FIG. 2 are turned on, so that a voltage is transmitted to some of the R columns, and thus red light is displayed.

Next, the SG switches of FIG. 1 are turned on so that the reference voltages of the resistor string 102 are transferred to the reference lines Ref 1, Ref 2,..., Ref 64 through the SG switches, and these reference voltages are decoders. (105, 106, etc.).

Then, the SD1 switches of the switch unit 210 of FIG. 2 are turned on to transmit voltage to some of the G columns, and thus green light is displayed.

Next, the SB switches of FIG. 1 are turned on so that the reference voltages of the resistance string 103 are transferred to the reference lines Ref 1, Ref 2,..., Ref 64 through the SB switches, and these reference voltages are decoders. (105, 106, etc.).

Then, the SD2 switches of the switch unit 210 of FIG. 2 are turned on, so that a voltage is transmitted to some of the B columns, and thus blue light is displayed.

Next, the SG switches of FIG. 1 are turned on again. The switches of the switch unit 210 that are turned on together are switches of SD3, not SD0 switches. Then, the red light of the other column is displayed.

In this order, the data drive circuit operates according to the control signal of FIG. 2 to transfer voltages to the pixel arrays.

4 illustrates a data driver according to an embodiment of the present invention.

A typical gamma voltage generator may set some voltage values selected by the DACs 441 and 442 among the reference voltages of the first resistor string 430 to voltages of some taps of the second resistor string 460. as a tab voltage.

Thus, a gamma voltage of a non-linear curve can be generated without adjusting the values of the respective resistors of the second resistor string.

By the way, such a conventional gamma voltage generator cannot produce all of the different gamma voltage curves for each of R, G, and B, so that the gamma voltage generator is provided for each color of R, G, and B, and thus gamma characteristics. The curve was adjusted.

According to an embodiment of the present invention, a switch unit 410, a memory unit 420, and a controller 120 are included to generate such gamma characteristic curves differently for each of R, G, and B.

The memory unit 420 may include a first memory unit 421 for storing digital data associated with a reference voltage level based on a gamma characteristic of a red color, and a second memory unit for storing digital data associated with a reference voltage level based on a gamma characteristic of a green color; The memory unit 422 and a third memory unit 423 for storing digital data associated with the reference voltage level according to the gamma characteristic of the blue color.

In the present exemplary embodiment, the memory units 421 to 423 are configured by including one memory unit according to gamma characteristics of the colors of R, G, and B included in the memory unit 420, but the memory units 420 to 423 are configured. The type, size, etc. of the digital data for each structure and color within the frame) may be variously changed.

For example, two or more memory units may be physically configured corresponding to each of RGB. Of course, the same effect may be realized by the digital data stored in the memory unit including two or more gamma characteristic curve information.

When the SR switch of the switch unit 410 is turned on, the digital data of the memory unit 421 is transferred to the DAC 441, 442, and the like, so that a plurality of reference voltages of the first resistance string 430 are provided. Some of the combinations are transferred to the second resistor string 460 through the buffers 451, 452, and the like.

Then, each reference voltage of the second resistance string 460 is adjusted to the gamma characteristic of the red color. The red gamma voltages generated are nonlinear overall and partially linear.

Next, when the SG switch of the switch unit 410 is turned on, the digital data of the memory unit 422 is transferred to the DAC 441, 442, and the like. Some other combination is passed through the buffers 451, 452, etc. to the second resistor string 460.

Then, each reference voltage of the second resistor string 460 is adjusted to the gamma characteristic of the green color.

Then, when the SB switch of the switch unit 410 is turned on (if the digital data of the memory unit 423 is transferred to the DAC 441, 442, etc.), the plurality of reference voltages of the first resistance string 430 are provided. And a combination of another portion of the second pass through the buffers (451, 452, etc.) to the second resistor string (460).

Then, each reference voltage of the second resistance string 460 is adjusted to the gamma characteristic of the blue color.

With this configuration, gamma voltages of R, G, and B are generated using one gamma voltage generator.

In addition, according to another embodiment of the present invention, the digital data related to the reference voltage level according to the gamma characteristic of each of R, G, and B may be selectively applied with a plurality of setting values.

For example, the digital data in the memory unit 421 may also be set differently according to a configuration value according to an environment setting of the display apparatus. In this case, it is possible to generate a custom gamma voltage according to market conditions, user characteristics, illuminance (brightness), etc., where the display device is used.

The waveform of the control signal transmitted by the controller 120 will be described below with reference to FIG. 5.

5 illustrates an exemplary waveform of a control signal input to a data driver according to an embodiment of the present invention.

SR, SG, and SB correspond to switches in the switch unit 410 of FIG. 5, respectively.

SD0 to SD5 correspond to switches in the switch unit 210 of FIG. 2.

Therefore, when the SR switches are turned on in this embodiment, red color light may be displayed in the SD0 and SD3 columns corresponding to the plurality of columns.

Similarly, when the SG switches are turned on, green light may be displayed in the SD1 and SD4 columns corresponding to the plurality of columns.

In addition, when the SB switches are turned on, blue color light may be displayed in the SD2 and SD5 columns corresponding to the plurality of columns.

In the above embodiments, in addition to the example of the control signal of FIG. 3 or 5, other control signals suitable for the pixel array characteristic or structure may be used.

6 illustrates a method of operating a data driver according to an embodiment of the present invention.

In operation S610, the switch unit 130 of FIG. 1 uses the reference voltage levels R1, R2,..., R64, G1, G2,..., G64, and B1 from the plurality of resistor strings 101 to 103. , B2, ..., B64).

In operation S620, the switch unit 130 selects any one of the resistor strings 101, 102, and 103 according to the control signal received from the controller 120. For example, resistor string 101 is selected when SR switches are turned on.

In this case, in step S630, the switch unit transfers reference inputs of the selected resistance string to the decoders 105 and 106 through the input terminal 110 and the output terminal 140.

Through this process, the number of reference lines does not increase for R, G, and B, but the reference voltage can be adjusted according to gamma characteristics for R, G, and B, respectively.

More details regarding the reference voltage level reception, selection and transfer are as described above with reference to FIGS.

7 illustrates a method of operating a data driver according to an embodiment of the present invention.

In step S710, at least one DAC 441 and 442 of the data driver shown in FIG. 4 receives digital values associated with a gamma characteristic corresponding to the column line to be currently displayed from the memory unit 420.

In this case, selective reception of the digital values may be performed by turning on one of the SR switch, the SG switch, or the SB switch of the switch unit 410.

The switch unit 410 receives the control signal from the control unit 120 and transmits digital data of any one of the memory unit 421, the memory unit 422, and the memory unit 423 to the DACs 441 and 442. The process is as described above with reference to FIGS.

In operation S720, the DACs 441 and 442 select some of the reference voltages of the first resistor string 430 by using the digital data transmitted as described above, and in operation S730, the DACs 441 and 442. And the like transfer the selected reference voltages through the buffers 451 and 452 to the second resistor string 460.

The reference voltages of the nodes of the second resistor string 460 are then adjusted to match the gamma characteristics of R, G, and B, respectively.

The above process is as described above with reference to FIGS. 4 to 5.

Method according to an embodiment of the present invention is implemented in the form of program instructions that can be executed by various computer means may be recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the equivalents of the claims, as well as the claims.

100: data driver
110: input terminal
120: control unit
130: switch unit
140: output terminal

Claims (15)

A first resistor string providing a plurality of reference voltage levels;
A second resistor string receiving at least one of a plurality of reference voltage levels provided by the first resistor string as at least one tap voltage to generate a reference voltage level corresponding to the gamma curve of the first color; And
A DAC that selects the at least one tap voltage among the plurality of reference voltage levels and provides the tap voltage to the second resistor string
Including, a data driver. The method of claim 1,
A memory unit configured to store digital data corresponding to the first color such that the DAC selects the at least one tap voltage corresponding to the gamma curve of the first color among the plurality of reference voltage levels.
Further comprising a data driver. The method of claim 2,
The first color is any one of red, green, and blue, and the memory unit stores digital data corresponding to each of the red, green, and blue. The method of claim 3,
The DAC sequentially receives digital data corresponding to each of the red, green, and blue from the memory unit and sequentially selects the at least one tap voltage to provide the second resistor string. The method of claim 4, wherein
And the second resistor string sequentially generates a plurality of reference voltage levels corresponding to the gamma curves of each of the red, green, and blue in accordance with the sequential provision of the at least one tap voltage of the DAC. A first resistor string for generating a reference voltage level;
At least one DAC delivering at least a portion of a reference voltage level generated by the first resistor string to a second resistor string; And
A memory unit for supplying digital data to select a reference voltage level that the at least one DAC transfers to the second resistor string
Including, a data driver. The method of claim 6,
The memory unit,
A first memory unit configured to store digital data associated with a reference voltage level according to a gamma characteristic of a red color;
A second memory unit for storing digital data associated with a reference voltage level according to a gamma characteristic of a green color; And
Third memory unit for storing digital data associated with the reference voltage level according to the gamma characteristics of the blue color
Including, a data driver. The method of claim 7, wherein
A switch unit which selects one of the first memory unit, the second memory unit, and the third memory unit to transfer digital data of the selected memory unit to the at least one DAC
Further comprising a data driver. The method of claim 8,
A control unit which transmits a control signal to the switch unit so that the switch unit selects one of the first memory unit, the second memory unit, and the third memory unit.
Further comprising a data driver. 10. The method of claim 9,
And the control unit transmits the control signal so that the switch unit sequentially selects the first memory unit, the second memory unit, and the third memory unit. Providing a plurality of reference voltage levels by the first resistor string of the data driver;
Receiving, by the DAC of the data driver, a digital value stored in a memory unit, selecting at least one tap voltage among a plurality of reference voltage levels provided by the first resistor string and providing the digital voltage to the second resistor string of the data driver; And
The second resistor string generating a reference voltage level corresponding to the gamma curve of the first color using the at least one tap voltage
Including a method of operating a data driver. delete delete At least one DAC of the data driver receiving, from the memory unit of the data driver, digital data associated with a reference voltage level according to a gamma characteristic of any one of red, green, and blue colors; And
The at least one DAC supplying at least a portion of the reference voltage levels of the first resistor string of the data driver to the second resistor string using the digital data;
Including a method of operating a data driver. A computer-readable recording medium containing a program for performing the method of claim 11.
KR1020100041484A 2010-05-03 2010-05-03 Data driver of display apparatus and method for operating data driver of display apparatus KR101174985B1 (en)

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