KR20080000293A - Display device, driving method of driving circuit for the same - Google Patents

Abstract

A display apparatus and a driving method of a driver used in the display apparatus are provided to improve image quality by reducing fine color difference in the same gray. A display apparatus includes a liquid crystal panel(10), an interface(30), and a timing controller(40). The liquid crystal panel includes pixel regions, which have plural sub-pixels, at cross sections, which are defined by gate and data lines. The interface delivers control and data signals received from outside. The timing controller, which includes a converting unit(50) for converting the data signals so as to have the same value or one gray difference value, generates control signals of a driver connected to the gate and data lines based on the control signals.

Description

Display device and driving method of driving circuit used therein {Display Device, driving method of driving circuit for the same}

1 is a block diagram schematically illustrating a configuration of a general liquid crystal display device.

2 is a schematic diagram for explaining a pixel configuration of a color and monochromatic liquid crystal display device.

3 is a block diagram schematically illustrating a structure of a display device according to an exemplary embodiment of the present invention.

4 is a schematic diagram for explaining a pixel configuration of a color and monochrome implementation liquid crystal display according to an embodiment of the present invention.

5 is a block diagram illustrating in more detail the structure of a driving circuit in a display device according to an exemplary embodiment of the present invention.

<Description of Symbols for Major Parts of Drawings>

10: liquid crystal panel 20: driving circuit part

30: interface 40: timing controller

50: converter 60: gate drive circuit

80: Data driver circuit Left, Center, Right: Data signal

DE, Hsync, Vsync: Control signal Vdata: Converted data signal

SOE, GOE: Gate and data drive circuit control signal

The present invention relates to a display device of the present invention, and more particularly, to a display device for improving image quality by varying a gradation representation method of a monochrome display device and a driving method of a driving circuit used therein.

Currently, in the field of display devices, cathode ray tubes (CRT) are used to realize images by using a magnetic field generated by a deflection yoke and a shadow mask called a color sorting device. ) And the ultraviolet rays emitted from the gas (Ne, Xe) filled in the space between the upper and lower substrates hit the phosphors to emit a unique visible light, and the screen emits phosphors by ultraviolet rays generated during gas discharge. An electric field is formed in the liquid crystal injected between the plasma display panel (PDP) that implements the image and the upper and lower substrates which are spaced apart by a predetermined distance, and light is incident on the BLU (Back Light Unit) to provide a signal voltage of the pixel. Therefore, a thin film transistor (Liquid Crystal Display, TFT-LCD) that displays an image by controlling light transmitted through the pixel and a transparent electrode (anode) are coated. There is an organic EL (Organic Electro-Luminescence Display) that inserts an organic light emitting material between a substrate and a metal cathode and flows an electric current to emit organic molecules to realize images, shapes, and characters.

Among the display devices, the liquid crystal display device having the highest commercialization ratio is the liquid crystal display device. The technical spirit of the present invention will be described below as an example of the liquid crystal display device.

FIG. 1 is a block diagram schematically illustrating a configuration of a general liquid crystal display device. As shown in FIG. 1, a liquid crystal panel 1 for displaying an image and a driving circuit unit 2 for driving the same are shown.

In the liquid crystal panel 1, a plurality of gate lines GL and data lines DL intersect each other, and a thin film transistor T is provided at an intersection thereof, and a first substrate on which pixel electrodes are formed, and also RGB three primary colors. The formed color filter and the second substrate on which the common electrode is formed are bonded to each other by a predetermined distance, and a liquid crystal material is injected therebetween, and the liquid crystal material is formed by an electric field formed through the pixel electrode and the common electrode. The image is displayed by changing the light transmittance.

The driving circuit unit 2 is an interface 3 connected to an external system (not shown) and transmitting a control signal and a data signal, and a gate driving circuit composed of a plurality of drive integrated circuits by using the control signal input thereto. 6) and generates a control signal for driving the data driver circuit 8 composed of a plurality of gate drive integrated circuits, and also transmits data signals input via the interface 3 to the data driver circuit 8. Is composed of a timing controller 4.

The operation of a general liquid crystal display device having such a structure will be briefly described as follows.

The interface 3 receives a data signal (RGB Data), horizontal and vertical synchronization signals (Hsync, Vsync), a data enable signal (DE), and the like, which are input to a driving circuit from an external system (not shown), and the timing controller 4. ). The interface function may be collected and configured together with the timing controller 4 to form a single chip.

The timing controller 4 receives a data signal and a control signal supplied from the interface 3 and generates a data signal and a control signal for driving the gate driver circuit 6 and the data driver circuit 8 accordingly. These signals are input to the gate driver circuit 6 and the data driver circuit 8, respectively.

The gate driving circuit 6 generates a gate output signal in response to the control signal supplied from the timing controller 4, and sequentially supplies the gate output signal to the liquid crystal panel 1 through the gate line GL.

The data driving circuit 8 converts a digital data signal into an analog video signal corresponding to a control signal and a data signal input from the timing controller 4, and converts the data signal into an analog video signal through the data line DL. Supply to the panel (1).

Accordingly, the liquid crystal panel 1 turns on / off the thin film transistor T provided through the gate driving signal and the image signal supplied from the gate driving circuit 6 and the data driving circuit 8. The image is displayed by changing the light transmittance of the liquid crystal cell.

When the liquid crystal display is used in a TV or a laptop, one pixel is composed of three sub-pixels each displaying RGB three primary colors.

Accordingly, in the case of an 8-bit driving liquid crystal display, the number of colors that one pixel can represent is expressed by Equation 1 below.

Red (2 ⁸ ) × Green (2 ⁸ ) × Blue (2 ⁸ ) = 16777216 ..... Equation 1

That is, about 1677 million colors are displayed.

In addition, in a monochrome liquid crystal display device displaying only a single color that is widely used in the field of medical devices, one pixel is composed of a single pixel.

Accordingly, in the case of an 8-bit driving liquid crystal display device, the gray number is represented by the following equation 2

Black (2 ⁸ ) = 256 ................... Equation 2

256 gray will be displayed.

When the liquid crystal display device displaying the RGB three primary colors is generally applied to a monochrome liquid crystal display device that displays only a single color commonly used in the field of medical devices, only one pixel is displayed because only the three primary colors are displayed. The number of grays that can be displayed is according to the following equation 3.

{Black (2 ⁸ )-Black (1)} × subpixel (3) + Black (1) = 766 ......... Equation 3

766 Gray will be displayed.

Therefore, as shown in Fig. 2, the pixel displaying 255 Gray has the subpixel left of 255 Gray, and the remaining subpixels each have the pixel of (a) displaying 0 Gray, the left subpixel, and the middle. The pixel of (b) in which the sub-pixel and the right sub-pixel display 43 Gray, 80 Gray, and 132 Gray, respectively, displays the same Gray.

In other words, even when one pixel displays the same 255 gray, the subpixels display different grays.

This causes a slight color difference in the same gray, resulting in deterioration of image quality.

The present invention reduces the color difference in the same gray that occurs when the display device displaying RGB three primary colors is applied to a monochrome display device that displays only a single color commonly used in the field of medical devices. It is an object of the present invention to provide a display device for improving image quality and a driving method of a driving circuit used therein.

In order to achieve the above object, in the display device according to the exemplary embodiment of the present invention, a pixel region is defined at a point where a gate line and a data line cross each other, and the pixel region is composed of a plurality of subpixels. and; An interface for transmitting a control signal and a data signal input from the outside; A converting unit receiving the data signal in sub-pixel units and converting the data signal to have the same or 1 gray difference value in the sub-pixel units, and through the control signal, a driving circuit connected to the gate line and the data line. And a timing controller for generating a control signal.

The converting unit may include: an adder configured to receive a data signal input from an external source as a monochromatic data signal, add a gray value of the data signal, and output a result value; It is characterized in that it comprises a divider and a counter for receiving the result value, and distributes so as to have a difference value of the same or 1 Gray.

The distributor receives the result value, and repeatedly subtracts the result value until it becomes zero.

The counter device includes a plurality of counter means corresponding to the sub-pixels.

The counter is characterized in that each time the distributor subtracts the result by one, the number of subtractions is accumulated by the counter means of the sub-pixel.

In order to achieve the above object, a driving method of a display device driving circuit according to an embodiment of the present invention comprises the steps of: receiving a data signal in sub-pixel units; Summing gray values of the data signals and generating a result value thereof; And distributing the result value by subpixels by the same or one difference.

The step of receiving the data signal in sub-pixel units includes: receiving the data signal in sub-pixel units of R, G, and B; Mapping subpixels of R, G, and B of the data signal into monochromatic data signals having subpixels of Left, Center, and Right, respectively; And inputting a gray value of each of the monochrome data signals.

The step of distributing the result value for each subpixel by the same or one difference may include: repeatedly performing subtraction operations by 1 until the result value becomes 0; Each time the subtraction operation is performed, the counter means corresponding to each sub-pixel may alternately accumulate the number of times.

Hereinafter, a display device according to an exemplary embodiment of the present invention and a driving method of a driving circuit used therein will be described with reference to the accompanying drawings.

FIG. 3 is a block diagram schematically illustrating the structure of a display device according to an exemplary embodiment of the present invention. Referring to FIG. 3, as shown in FIG. 3, a liquid crystal panel 10 displaying an image and driving the same. It consists of a driving circuit unit 20.

In the liquid crystal panel 10, a plurality of gate lines GL and data lines DL intersect each other, and a thin film transistor T is provided at an intersection thereof, a first substrate on which a pixel electrode is formed, and a common electrode are formed. The second substrate is spaced apart from each other by a predetermined distance, and the liquid crystal material is injected therebetween. The liquid crystal panel 10 having such a structure displays an image by changing the light transmittance of the liquid crystal material by an electric field formed through the pixel electrode and the common electrode.

The driving circuit unit 20 is connected to an external system (not shown) to transfer a control signal and a data signal to the interface 30 and a gate driving circuit composed of a plurality of drive integrated circuits by using the control signal input thereto ( 60 and a timing controller 40 for generating a control signal for driving the data driver circuit 80 including a plurality of gate drive integrated circuits, and a data signal input through the interface 30. It consists of a conversion unit 50 for converting them.

Here, the control signal further includes other signals in addition to the signals described below, and only some of the signals (GOE, SOE) will be described as an example.

More specifically, the interface 30 receives a data signal, horizontal and vertical synchronous signals (Hsync, Vsync), a data enable signal (DE), etc., which are input to a driving circuit from an external system (not shown), and receives a timing controller ( 40).

In this case, the data signal is input in units of red, green, and blue sub-pixels constituting one pixel in the color spherical liquid crystal display, and corresponds to a single color data signal (Left, Center, Right).

The timing controller 40 receives the horizontal and vertical synchronization signals Hsync and Vsync and the data enable signal DE supplied from the interface 30, and correspondingly, the gate driving circuit 60 and the data driving circuit 80 are received. The control signals GOE and SOE necessary for driving) are generated and the signals GOE and SOE are supplied to the gate driver circuit 60 and the data driver circuit 80, respectively.

In addition, the timing controller 40 receives the monochrome data signals Left, Center, and Right input from the interface 30 to the conversion unit 50 provided therein, and the monochrome data signals Left, Center, and Right. After the gray level deviation is converted into the smallest form, the rearranged data signal Vdata is generated and supplied to the data driving circuit 80.

As illustrated in FIG. 4, the monochromatic data signal Left, Center, and Right in the conversion unit 50 is a pixel displaying 255 Gray input to the timing controller 40. And the other subpixels of (a) which respectively display 0 Gray, or (b) which the left subpixel, the middle subpixel, and the right subpixel represent 43 Gray, 80 Gray and 132 Gray, respectively. The pixel is converted into the pixel of (c) in which the left subpixel, the intermediate subpixel, and the right subpixel display 85 Gray, 85 Gray, and 85 Gray, respectively, through the conversion unit 50.

Accordingly, the timing controller 40 generates a monochromatic data signal Left, Center, Right having little gray difference of each sub-pixel forming one pixel, rearranges it, and supplies the same to the data driving circuit 80. .

The gate driving circuit 60 generates a gate output signal in response to the control signal GOE supplied from the timing controller 40, and sequentially supplies the gate output signal to the liquid crystal panel 10 through the gate line GL. do.

The data driver circuit 80 converts the digital data signal Vdata into an analog video signal in response to the control signal SOE and the data signal Vdata input from the timing controller 40. The liquid crystal panel 10 is supplied to the liquid crystal panel 10 through a data line DL.

Accordingly, the liquid crystal panel 10 turns on / off the thin film transistor T provided through the gate driving signal and the image signal supplied from the gate driving circuit 60 and the data driving circuit 80. The image is displayed by changing the light transmittance of the liquid crystal cell.

FIG. 5 is a block diagram illustrating the structure of a driving circuit in detail in the display device according to an exemplary embodiment of the present invention. Referring to FIG. 5, the timing controller 40 may include a single color data signal from an interface (not shown). Left, Center, Right input from the conversion unit 50 for converting and outputting, the image signal processing unit 42 for rearranging the data signal output from the conversion unit 50 and from the interface (not shown) A control signal processor 44 receives the control signal DE, generates control signals GOE and SOE corresponding thereto, and outputs them to the gate and the data driving circuit (not shown).

In addition, the conversion unit 50 includes a summer 52 for summing up the input signal, a divider 54 for distributing a result value input through the summer 52, and the divider 54. The distributed signal value is composed of a counter device 56 composed of a plurality of first to third counter means 56a, 56b, and 56c respectively corresponding to the sub-pixels.

5, the operation of the display device driving circuit according to the embodiment of the present invention is as follows.

The timing controller 40 receives an externally supplied control signal DE and monochromatic data signals Left, Center, and Right through an interface (not shown).

The conversion unit 50 included in the timing controller 40 receives the monochromatic data signals Left, Center, and Right in the summer 52.

The summer 52 receives each of the monochromatic data signals Left, Center, and Right, sums the gray values thereof, and inputs the resultant values to the divider 54.

The divider 54 repeatedly decrements by one until the input result value becomes a zero value. Here, each time one decreases, the first to third counter means 56a, 56b, 56c corresponding to each sub-pixel of the counter device 56 sequentially accumulate the number of subtractions. That is, the divider 54 and the counter 56 distribute the gray values of the input monochrome data signals Left, Center, and Right by the same or different ones.

The counter 56 inputs the gray value of each corresponding sub-pixel to the video signal processor 42 through the first to third counter means 56a, 56b, 56c.

The image signal processor 42 rearranges the gray values of the corresponding sub-pixels input to the counter 56 in a form that can be processed by a data driving circuit (not shown), and supplies them.

The control signal processor 44 of the timing controller 40 generates and supplies control signals GOE and SOE of the gate and data driving circuits corresponding to the control signal DE supplied from the outside.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art various modifications and variations of the present invention without departing from the spirit and scope of the present invention described in the claims below I can understand that you can.

Therefore, the display device according to the embodiment of the present invention and the driving method of the driving circuit used therein eliminate the difference in the fine color that occurs when the display device designed for color implementation is applied to the display device for monochrome implementation. Thus, the image quality can be improved.

Claims (8)

A pixel region is defined at a point where the gate line and the data line cross each other, and the pixel region includes a plurality of subpixels; An interface for transmitting a control signal and a data signal input from the outside; A control unit for receiving the data signal in sub-pixel units and converting the data signal to have the same or 1 gray difference value in the sub-pixel units, and controlling the driving circuit connected to the gate line and the data line through the control signal And a timing controller for generating a signal. According to claim 1, The converting unit may include: an adder configured to receive a data signal input from an external source as a monochromatic data signal, add a gray value of the data signal, and output a result value; And a divider and a counter for receiving the result value and distributing the result value to have a difference value equal to or equal to 1 gray. The method of claim 2, And the divider receives the result value and repeatedly subtracts the result value until the result value becomes zero. The method of claim 2, And the counter device includes a plurality of counter means corresponding to the sub-pixels. The method of claim 4, wherein And the counter accumulates the number of subtractions by the counter means of the sub-pixel each time the divider subtracts the result value by one. Receiving a data signal in sub-pixel units; Summing gray values of the data signals and generating a result value thereof; Dividing the result value by subpixels by the same or one difference; A driving method of a display device driving circuit comprising a. The method of claim 6, Receiving the data signal in sub-pixel units, Receiving the data signal in subpixel units of R, G, and B; Mapping subpixels of R, G, and B of the data signal into monochromatic data signals having subpixels of Left, Center, and Right, respectively; And a gray level value of each of the monochrome data signals is input. The method of claim 6, Distributing the result value for each subpixel by the same or 1 difference, Performing a subtraction operation repeatedly by 1 until the result value becomes 0; Accumulating the number of times by counter means corresponding to each sub-pixel alternately each time the subtraction operation is performed; A driving method of a display device driving circuit comprising a.

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