KR102187836B1 - Display driving apparatus - Google Patents

Abstract

The present invention discloses a display driving apparatus. Such a display driving apparatus is a display driving apparatus that provides first to fourth data signals to a unit display area of a display panel, wherein the first to third data signals having pixel information are buffered and output. An output buffer unit including three buffers; And a selector configured to switch the fourth data signal and the first to third data signals having a fixed value to be applied to the corresponding first to fourth pads, respectively.

Description

Display driving device {DISPLAY DRIVING APPARATUS}

The present invention relates to a display device, and more particularly, to a display driving device capable of obtaining benefits of reducing the area of an integrated circuit, reducing power consumption, and reducing heat generation.

In general, a display device includes a display panel having a plurality of gate lines and a plurality of data lines, a gate driving circuit supplying gate driving signals to a plurality of gate lines, a data driving circuit supplying data signals to a plurality of data lines, and pixels. It may include a timing controller or the like that transmits a data signal having information to the data driving circuit.

The display panel may be composed of a liquid crystal display panel, an OLED display panel, or the like.

The liquid crystal display panel consists of a lower substrate on which a pixel electrode is formed, an upper substrate on which a common electrode is formed, and a liquid crystal layer interposed therebetween. A voltage is applied to the pixel electrode to rearrange the liquid crystal molecules in the liquid crystal layer to pass through the liquid crystal layer. Adjust the transmittance of light.

The OLED display panel includes an organic light-emitting device, and when a voltage is applied, a current flows through the organic light-emitting device to emit light.

Red (R), green (G), and blue (B) pixels are formed on the display panel, and each pixel is driven by a data signal to perform a display operation. Recently, in order to further improve luminance, an RGBW method in which a white (W) pixel is further added as an example of an additional pixel to the red (R), green (G) and blue (B) pixels has been proposed.

The data driving circuit may include an output buffer unit for buffering and outputting the data signal, and the output buffer unit may include a number of amplifiers for amplifying and outputting the data signal.

However, as the number of pixels in the display panel increases as in the RGBW method, the number of amplifiers in the output buffer unit increases significantly, and thus, problems such as an increase in the area of the integrated circuit of the data driving circuit, increase in power consumption, and increase in heat generation may occur.

An object of the present invention is to provide a display driving apparatus capable of obtaining gains in reducing an area of an integrated circuit, reducing power consumption, and reducing heat generation by excluding an amplifier corresponding to a data signal having a fixed value.

In addition, the present invention provides a selection unit for switching a data signal having pixel information and a data signal having a fixed value between the data driving circuit and the display panel, thereby driving a relatively large number of data lines with a relatively small number of channels. It is an object to provide a display driving device capable of.

In the display driving apparatus according to the present invention, in the display driving apparatus providing first to fourth data signals to a unit display area of a display panel, the first to third data signals having pixel information are buffered and output. An output buffer unit including first to third buffers; And a selector configured to switch the fourth data signal and the first to third data signals having a fixed value to be applied to the corresponding first to fourth pads, respectively.

In addition, a display driving apparatus according to the present invention includes: a data driving circuit including first to third channels for outputting first to third data signals in response to pixel information; A source for generating a fourth data signal having a fixed value; And a selector configured to switch the first to third data signals and the fourth data signals through the first to third channels to be applied to corresponding first to fourth pads, respectively.

In the present invention, by excluding an amplifier corresponding to a data signal having a fixed value, an integrated circuit area reduction, power consumption reduction, and heat generation reduction can be obtained.

In addition, the present invention provides a selection unit between the data driving circuit and the display panel for switching a data signal having pixel information and a data signal having a fixed value, thereby driving a relatively large number of data lines with a relatively small number of channels. I can.

1 is a circuit diagram showing an embodiment of a display driving apparatus according to the present invention.
FIG. 2 is a table showing an example of pixel information of FIG. 1.
3 to 6 are diagrams for explaining the operation process of FIG. 1.
7 is a block diagram showing another embodiment of a display driving apparatus according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Terms used in the present specification and claims are not limited to a conventional or dictionary meaning and are not interpreted, but should be interpreted as meanings and concepts consistent with the technical matters of the present invention.

Since the embodiments described in the present specification and the configurations shown in the drawings are preferred embodiments of the present invention, and do not represent all the technical spirit of the present invention, various equivalents and modifications that can replace them at the time of the present application are There may be.

An embodiment of the present invention discloses a display driving apparatus in which a data signal having pixel information uses a buffer and a data signal having a fixed value excludes a buffer so as to obtain benefits of reducing the area of an integrated circuit, reducing power consumption, and reducing heat generation. do.

An embodiment of the present invention discloses a display driving apparatus including a selection unit implementing an interface between a data driving circuit and a display panel so that a relatively large number of data lines can be driven with a relatively small number of channels.

The embodiment of the present invention exemplifies outputting first to fourth data signals to a unit display area of a display panel for simplicity of description.

1 is a circuit diagram showing an embodiment of a display driving apparatus according to the present invention.

Referring to FIG. 1, a display driving apparatus 80 according to an embodiment of the present invention includes a latch unit 10, a digital-to-analog converter (DAC) unit 20, an output buffer unit 30, and a selection unit. It includes (40).

The latch unit 10 latches the pixel information provided from the control unit 60 (shown in FIG. 7) and provides it to the DAC unit 20, and the DAC 20 converts it to analog to the output buffer unit 30. to provide.

The output buffer unit 30 buffers the first to third data signals DATA1, DATA2, and DATA3 corresponding to pixel information provided from the DAC 20 and outputs the first to third buffers BUF1, BUF2, and BUF3. ).

The selector 40 includes first to fourth pads R_OUT, W_OUT, G_OUT, and B_OUT to which the first to third data signals DATA1, DATA2, and DATA3 and the fourth data signal DATA_REF having a fixed value respectively correspond. ), and perform the switching operation. According to an embodiment of the present invention, the first to third data signals DATA1, DATA2, and DATA3 having pixel information are input to the selection unit 40 through the output buffer unit 30, and a fourth data signal having a fixed value ( DATA_REF) is configured to be input to the selection unit 40 without passing through the output buffer unit 30.

The selection unit 40 includes first to fourth data signals corresponding to each of the first to fourth data signals corresponding to a case of WGB, RGB, or RWB, or RWG allocated to the first to fourth data signals. The switch is applied to the pads R_OUT, W_OUT, G_OUT, and B_OUT and provided to the display panel 50.

For example, among the red (R), green (G), blue (B), and white (W) pixel information, the first to third data signals DATA1, DATA2, and DATA3 have W, G, and B pixel information. The case surface selector 40 applies the fourth data signal DATA_REF to the first pad R_OUT, and applies the first to third data signals to the corresponding second pads W_OUT, G_OUT, and B_OUT. Apply to. Other examples corresponding to the case in which the first to third data signals DATA1, DATA2, and DATA3 are input to R G B, R W B, or R W G will be described in detail in the operation of FIGS. 2 to 6.

Here, the fourth data signal DATA_REF has a level for black processing one pixel. The fourth data signal DATA_REF may be supplied from inside or outside the display driving device. As an example, it may be configured to be supplied from an internal source that supplies a gamma voltage to the DAC unit 20. Alternatively, a voltage having a predetermined level may be supplied from an external source of the display driving device.

In addition, the selection unit 40 sets the first to fourth data signals DATA1, DATA2, DATA3, and DATA_REF of the corresponding display panel 50 according to a control signal provided from the control unit 60 (shown in FIG. 7). It may be configured to be transmitted to the first to fourth pads R_OUT, W_OUT, G_OUT, and B_OUT.

Here, the control signal is determined in response to pixel information provided by the control unit 60 to the latch unit 10. For example, when W, G, and B pixel information is provided, the control signal applies the fourth data signal DATA_REF to the first pad R_OUT, and applies the first to third data signals to the second pad to the fourth pad W_OUT. , G_OUT, B_OUT) are determined to be applied respectively. A more detailed description and another example will be described in detail in the operation process of FIGS. 2 to 6.

The selection unit 40 may be configured as a multiplexer. The selector 40 includes a first switch SW1, first, second, and fourth data signals DATA1, DATA2, and DATA_REF that perform switching in response to the first and fourth data signals DATA1 and DATA_REF. The second switch SW2 performs switching in response to the second, third, and fourth data signals DATA2, DATA3, and DATA_REF, and a third switch SW3 and the third and third switches perform switching. And a fourth switch SW4 that performs switching in response to the 4 data signals DATA3 and DATA_REF. Here, the first to fourth switches SW1, SW2, SW3, and SW4 are configured to select different data signals.

In addition, the first switch SW1 includes a first common terminal C1, a first source terminal S1, and a second source terminal S2, and the second switch SW2 is a second common terminal C2. , A second source terminal S2, a third source terminal S3, and a fourth source terminal S4. The third switch SW3 includes a third common terminal C3, a fourth source terminal S4, a fifth source terminal S5, and a sixth source terminal S6, and the fourth switch SW4 is It includes a 4 common terminal (C4), a sixth source terminal (S6), and a seventh source terminal (S7). Here, the first and second switches SW1 and SW2 share the second source terminal S2, the second and third switches SW2 and SW3 share the fourth source terminal S4, and the third , The fourth switches SW3 and SW4 may be configured to share the sixth source terminal S6.

The first to fourth pads R_OUT, W_OUT, G_OUT, and B_OUT of the display panel 50 are the first to fourth common terminals C1 and C2 of the first to fourth switches SW1, SW2, SW3, and SW4. Each of the first to fourth pads R_OUT, W_OUT, G_OUT, and B_OUT are connected to the first to fourth data lines provided in the display panel 50, respectively.

2 is a table showing an example of pixel information of FIG. 1, and FIGS. 3 to 6 are diagrams for explaining an operation process of FIG. 1 corresponding to pixel information.

Specifically, FIG. 3 is a circuit diagram for explaining an operation process when W, G, and B are input for pixel information, and FIG. 4 is a circuit diagram for explaining an operation process when R, G, and B are input. 5 is a circuit diagram for explaining the operation process when R, W, and B are input, and FIG. 6 is a circuit diagram for explaining the operation process when R, W, and G are input.

First, an operation process when W, G, B is inputted as pixel information is as follows.

2 and 3, the first to third buffers BUF1, BUF2, and BUF3 output first to third data signals DATA_W, DATA_G, and DATA_B corresponding to W, G, and B.

Then, the first switch SW1 switches to the first source terminal S1, the second switch SW2 switches to the second source terminal S2, and the third switch SW3 switches to the fourth source terminal ( S4), and the fourth switch SW4 switches to the sixth source terminal S6.

The fourth data signal DATA_REF is applied to the first pad R_OUT by switching of the first to fourth switches SW1, SW2, SW3, and SW4, and the second to fourth pads W_OUT, G_OUT, and B_OUT. ) Is applied with the first to third data signals DATA_W, DATA_G, and DATA_B.

The operation process when R, G, B is inputted as pixel information is as follows.

2 and 4, the first to third buffers BUF1, BUF2, and BUF3 output first to third data signals DATA_R, DATA_G, and DATA_B corresponding to R, G, and B.

Then, the first switch SW1 switches to the second source terminal S2, the second switch SW2 switches to the third source terminal S3, and the third switch SW3 is switched to the fourth source terminal ( S4), and the fourth switch SW4 switches to the sixth source terminal S6.

The fourth data signal DATA_REF is applied to the second pad W_OUT by switching of the first to fourth switches SW1, SW2, SW3, and SW4, and the first, third, and fourth pads R_OUT, The first to third data signals DATA_R, DATA_G, and DATA_B are applied to G_OUT and B_OUT.

The operation process when R, W, and B is input as pixel information is as follows.

2 and 5, the first to third buffers BUF1, BUF2, and BUF3 output first to third data signals DATA_R, DATA_W, and DATA_B corresponding to R, W, and B.

Then, the first switch SW1 switches to the second source terminal S2, the second switch SW2 switches to the fourth source terminal S4, and the third switch SW3 is switched to the fifth source terminal ( S5), and the fourth switch SW4 switches to the sixth source terminal S6.

The fourth data signal DATA_REF is applied to the third pad G_OUT by switching of the first to fourth switches SW1, SW2, SW3, and SW4, and the first, second, and fourth pads R_OUT, The first to third data signals DATA_R, DATA_W, and DATA_B are applied to W_OUT and B_OUT.

The operation process when R, W, G is inputted as pixel information is as follows.

2 and 6, the first to third buffers BUF1, BUF2, and BUF3 output first to third data signals DATA_R, DATA_W, and DATA_G corresponding to R, W, and G.

Then, the first switch SW1 switches to the second source terminal S2, the second switch SW2 switches to the fourth source terminal S4, and the third switch SW3 switches to the sixth source terminal ( S6), and the fourth switch SW4 switches to the seventh source terminal S7.

By switching of the first to fourth switches SW1, SW2, SW3, and SW4, the fourth data signal DATA_REF is applied to the fourth pad B_OUT, and the first to third pads R_OUT, W_OUT, G_OUT ) Is applied with the first to third data signals DATA_R, DATA_W, and DATA_G.

In this way, the selector 40 sets the first to fourth data signals DATA1, DATA2, DATA3, and DATA_REF respectively corresponding to the case input to WGB, RGB, RWB, or RWG. A switching operation is performed to be applied to the pads R_OUT, W_OUT, G_OUT, and B_OUT. In addition, the selection unit 40 displays the first to fourth data signals DATA1, DATA2, DATA3, and DATA_REF according to a control signal determined in response to a case input to WGB, RGB, RWB, or RWG. A switching operation is performed to be applied to the first to fourth pads R_OUT, W_OUT, G_OUT, and B_OUT of 50. FIG. 7 is a block diagram showing another embodiment of a display driving apparatus according to the present invention.

Referring to FIG. 7, a display driving apparatus according to another exemplary embodiment of the present invention includes a data driving circuit 70 and a selection unit 40. The data driving circuit 70 includes first to third channels 72, 74, and 76 for outputting first to third data signals DATA1, DATA2, and DATA3 in response to pixel information. The selection unit 40 applies the first to third data signals DATA1, DATA2, and DATA3 and the fourth data signals DATA_REF by the first to third channels 72, 74 and 76 in response to a predetermined case. A switching operation is performed so as to be applied to the corresponding first to fourth pads R_OUT, W_OUT, G_OUT, and B_OUT, respectively.

The data driving circuit 70 includes a latch unit 10, a DAC unit 20 and an output buffer unit 30. The data driving circuit 70 outputs first to third data signals DATA1, DATA2, and DATA3 through the first to third channels 72, 74, and 76. Here, the first channel 72 includes a first latch LATCH1, DAC1, and a first buffer BUF1, and the second channel 74 is a second latch LATCH2, DAC2, and a second buffer BUF2. And the third channel 76 indicates that the third latch LATCH3, the DAC3, and the third buffer BUF3 are included.

The fourth data signal DATA_REF may be provided from a designated source, and the source may be configured inside or outside the display driving device. For example, a gamma voltage unit (not shown) for supplying a gamma voltage to the DAC unit 20 inside the display driving device is used as a source, or as an external example of the display driving device, in a power supply device (not shown). It can be configured by supplying a voltage having a certain level.

The selection unit 40 includes first to third data signals DATA1, DATA2, and DATA3 and fourth data signals according to a control signal determined in response to pixel information allocated to the first to third channels 72, 74, and 76. The data signal DATA_REF is switched to be applied to the first to fourth pads R_OUT, W_OUT, G_OUT, and B_OUT of the corresponding display panel 50, respectively.

For example, when pixel information W, G, and B are allocated to the first to third channels 72, 74, and 76, the control signal applies the fourth data signal DATA_REF to the first to third pads R_OUT. It is determined to apply the data signal to the second to fourth pads W_OUT, G_OUT, and B_OUT, respectively.

In addition, when pixel information R, G, and B are allocated to the first to third channels 72, 74, and 76, the control signal transmits the fourth data signal DATA_REF to the second pad W_OUT. It is determined to apply signals to the first, third, and fourth pads R_OUT, G_OUT, and B_OUT, respectively.

In addition, when pixel information R, W, and B are allocated to the first to third channels 72, 74, and 76, the control signal transmits the fourth data signal DATA_REF to the third pad G_OUT. It is determined to apply signals to the first, second, and fourth pads R_OUT, W_OUT, and B_OUT, respectively.

In addition, when pixel information R, W, and G are allocated to the first to third channels 72, 74, 76, the control signal transmits the fourth data signal DATA_REF to the fourth pad B_OUT. A signal is determined to be applied to the first to third pads R_OUT, W_OUT, and G_OUT, respectively.

The selector 40 connects one channel of the data driving circuit 70 to a plurality of data lines, and transmits a data signal supplied through one channel to a plurality of data lines with a time difference.

Accordingly, the display panel 50 turns on the pixels in the selected row according to the gate driving signal supplied through the gate driving circuit (not shown), and the first to third data signals supplied from the data driving circuit 70 and the The fourth data signal having a fixed value is sequentially supplied to the unit display area of the display panel 50 through the selection unit 40 at a time difference to display an image.

Meanwhile, the display device according to an exemplary embodiment of the present invention may further include a controller 60 that provides pixel information to the data driving circuit 70 and provides a control signal to the selector 40.

The data driving circuit 70 outputs first to third data signals DATA1, DATA2, and DATA3 through the first to third channels 72, 74 and 76 in response to pixel information input from the control unit 60. do.

The selection unit 40 is a display panel in which a fourth data signal DATA_REF having a fixed value and the first to third data signals DATA1, DATA2, and DATA3 respectively correspond according to a control signal input from the control unit 60 The switching is applied to the first to fourth pads R_OUT, W_OUT, G_OUT, and B_OUT of 50.

The control unit 60 determines a control signal for controlling the switching operation of the selection unit 40 in response to pixel information provided to the data driving circuit 70 and provides it to the selection unit 40.

As described above, according to the present invention, the data driving circuit 70 includes the selection unit 40 for switching the first to third data signals DATA1, DATA2, and DATA3 having pixel information and the fourth data signal DATA_REF having a fixed value. By providing it between the and the display panel 50, it is possible to drive a relatively large number of data lines with a relatively small number of channels.

In addition, according to the present invention, by excluding the amplifier corresponding to the fourth data signal DATA_REF having a fixed value, the integrated circuit area can be reduced, power consumption can be reduced, and heat generation can be reduced.

10: latch unit 20: DAC unit
30: output buffer unit 40: selection unit
50: display panel 60: control unit
70: data driving circuit 80: display driving device

Claims (11)

In the display driving apparatus for providing first to fourth data signals to a unit display area of a display panel,
An output buffer unit including first to third buffers for buffering and outputting the first to third data signals having pixel information; And
A selector configured to switch the fourth data signal and the first to third data signals having a fixed value to be applied to corresponding first to fourth pads, respectively;
Display driving device comprising a. The method of claim 1, wherein the fourth data signal is
A display driving device, characterized in that it has the fixed value for black processing one pixel. The method of claim 1, wherein the selection unit
Each of the first to fourth data signals is applied to the corresponding first to fourth pads in response to a case of WGB, RGB, or RWB, or RWG allocated to the first to third data signals. A display driving device that switches as possible. The method of claim 1, wherein the selection unit
And switching the first to fourth data signals to be applied to the corresponding first to fourth pads according to a control signal. The method of claim 4, wherein the control signal is
A display driving apparatus, characterized in that it is determined in response to the pixel information. The method of claim 1, wherein the selection unit
Display driving apparatus comprising a multiplexer. The method of claim 1, wherein the selection unit
A first switch performing switching in response to the first and fourth data signals;
A second switch for performing switching in response to the first, second, and fourth data signals;
A third switch performing switching in response to the second, third, and fourth data signals; And
And a fourth switch for performing switching in response to the third and fourth data signals, and
The first to fourth switches select different data signals. The method of claim 7,
The first switch includes a first common terminal, a first source terminal, and a second source terminal,
The second switch includes a second common terminal, a second source terminal, a third source terminal, and a fourth source terminal,
The third switch includes a third common terminal, a fourth source terminal, a fifth source terminal, and a sixth source terminal,
The fourth switch includes a fourth common terminal, a sixth source terminal, and a seventh source terminal,
The first switch and the second switch share the second source terminal,
The second switch and the third switch share the fourth source terminal,
And the third switch and the fourth switch share the sixth source terminal. A data driving circuit including first to third channels for outputting first to third data signals in response to pixel information;
A source for generating a fourth data signal having a fixed value; And
A selector configured to switch the first to third data signals and the fourth data signals according to the first to third channels to be applied to corresponding first to fourth pads, respectively;
Display driving device comprising a. The method of claim 9, wherein the selection unit
A display driving device that switches so that the first to fourth data signals are applied to the corresponding first to fourth pads according to a control signal determined in response to the pixel information. The method of claim 9, wherein the selection unit
Display switching so that the first to fourth data signals are respectively applied to the corresponding first to fourth pads in response to the case of WGB, RGB, or RWB, or RWG allocated to the first to third channels drive.

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