KR102288325B1 - Display Device with Heating Control Apparatus - Google Patents

Abstract

The present invention relates to a heating control device for a display device, a first method of changing a combination of a charge sharing (CS) control mode and an inversion method when a specific heating image pattern is input, and a constant driving voltage (Vdd) By selectively applying one or more of the second methods of reducing the degree and compensating for the decrease in luminance with a backlight, heat generation in the data driving circuit can be minimized without deterioration of image quality or power consumption.

Description

Display Device with Heating Control Apparatus

The present invention relates to a display device, and more particularly, to a display device including a heat control device capable of minimizing heat generated in a drive circuit (D-IC) when a specific heat image pattern is input.

As the information society develops, the demand for a display device for displaying an image is increasing in various forms, and in recent years, a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting Various display devices such as an organic light emitting diode display device (OLED) are being used.

Among them, a liquid crystal display (LCD) displays an image by adjusting the light transmittance of the liquid crystal using an electric field. To this end, the liquid crystal display device includes a liquid crystal display panel in which liquid crystal cells are arranged in a matrix, and a driving circuit for driving the liquid crystal display panel.

A plurality of gate lines GL and data lines DL intersect in the pixel array of the liquid crystal display panel, and thin film transistors for driving the liquid crystal cells Clc at the intersections of the gate lines GL and data lines GL (Thin Film Transistor; hereinafter referred to as "TFT") is formed. In addition, a storage capacitor Cst for maintaining the voltage of the liquid crystal cell Clc is formed in the liquid crystal display panel. The liquid crystal cell Clc includes a pixel electrode, a common electrode, and a liquid crystal layer. An electric field is applied to the liquid crystal layers of the liquid crystal cells Clc by the data voltage applied to the pixel electrode and the common voltage Vcom applied to the common electrode. An image is realized by adjusting the amount of light passing through the liquid crystal layer by this electric field.

The driving circuit includes a gate driving circuit for sequentially supplying a gate output signal to the gate lines, and a data driving circuit for supplying a video signal (ie, a data voltage) to the data lines.

This data driving circuit is also referred to as a D-IC, and drives data lines to supply data voltages to the liquid crystal cells Clc.

The gate driving circuit sequentially drives the gate lines to select the liquid crystal cells Clc of the display panel to which the data voltage is to be supplied, one by one horizontal line.

The gate driving circuit includes a gate shift register configured with a plurality of stages to sequentially generate gate signals. Each stage of the shift register outputs a gate output signal Vout having a gate clock signal CLK and a low potential voltage Vss level by alternately charging and discharging. Each of the output terminals of the stages is connected one-to-one to the gate lines. The first level gate signal from the stages is sequentially generated once per frame and supplied to the corresponding gate line.

On the other hand, a structure in which such a gate driving circuit is directly formed on an array substrate is referred to as a gate-in-panel (GIP) structure. In this GIP structure, a plurality of circuit blocks for providing a gate output signal Vout to each gate line. of GIP blocks are formed directly on the panel.

On the other hand, such a data driving circuit (D-IC) not only consumes a lot of power, but also generates a lot of heat in proportion to the power consumption.

Various mechanical heat dissipation means have been developed to dissipate the heat generated by the D-IC, but they have various disadvantages due to the cumbersome installation and mechanical characteristics.

On the other hand, in the driving circuit of the liquid crystal display currently being developed, an inversion method is used in which the polarity of the data voltage is inverted in a predetermined unit in terms of power consumption, heat generation and deterioration prevention, etc., and this inversion method is also applied. In order to reduce power consumption due to polarity reversal of the data signal, the output terminal of the data driving circuit divides the average common charge inside the liquid crystal panel to increase (decrease) the pixel voltage to the common voltage (Vcom) level. A charge-sharing control (CSC) or charge-sharing control technology that reduces the burden on the data driving circuit is applied.

These inversion and charge sharing control technologies are used by applying various combinations of methods depending on the structure of the display panel, input image data, possible power consumption, and the like.

However, in the case of a kind of heating image pattern in which the entire display panel or a significant area is displayed as image data of the same grayscale in a special environment such as a test process of a display panel or screen adjustment, excessive heat may occur depending on the inversion or charge-sharing method applied at the time. Problems may arise.

Accordingly, the present invention aims to solve problems such as deterioration due to circuit heat by dynamically changing the inversion method and the charge sharing control method so that heat generation can be minimized when image data corresponding to a problem pattern is input.

Against this background, it is an object of the present invention to provide a display device capable of minimizing heat generation in a data driving circuit.

Another object of the present invention is to provide a display device that minimizes heat generation in a data driving circuit by changing a combination of a charge sharing control mode and an inversion method with respect to a specific input image pattern.

Another object of the present invention is to provide a display device that minimizes heat generation in a data driving circuit without changing the luminance by reducing the driving voltage Vdd to a certain extent when inputting a heating image pattern and compensating for the decrease in luminance with a backlight. .

Another object of the present invention is to provide a first method for changing a combination of a charge-searing control mode and an inversion method when a problem pattern with large heat generation is input as an input image, and to reduce the driving voltage Vdd to a certain extent and It is to provide a display device capable of minimizing heat generation in a data driving circuit without deterioration of image quality or power consumption by applying all of the second method of compensating for a decrease in luminance with a backlight.

In order to achieve the above object, according to one aspect of the present invention, a display panel including a plurality of pixels defined by a cross region of a gate line and a data line, and a data output signal to the data line according to an input image pattern A data driver that is generated and provided and a heat control device for controlling the amount of heat generated by the data driver, wherein the heat control device includes a heat pattern detector for determining whether the input image pattern is a heat image pattern, and a heat image pattern a main control unit generating and outputting CS/inversion change information; and CS mode and inversion applying the target inversion method and the charge sharing mode to the data output signal applied to the data line according to the CS/inversion change information A display device including a change unit is provided.

In another embodiment of the present invention, a display panel including a plurality of pixels defined by a cross region of a gate line and a data line, a data driver generating and providing a data output signal to the data line according to an input image pattern, and the a heating control device for controlling the amount of heat generated by the data driver, wherein the heating control device includes a heating pattern detector for determining whether the input image pattern is a heating image pattern, and generating driving voltage change information in the case of the heating image pattern Provided is a display device comprising: a main controller that outputs; and a driving voltage changer that generates a backlight compensation signal capable of compensating for a decrease in luminance according to the driving voltage change information and transmits the generated backlight compensation signal to the backlight controller.

In another embodiment of the present invention, a display panel including a plurality of pixels defined by a cross region of a gate line and a data line, a data driver generating and providing a data output signal to the data line according to an input image pattern; and a heat control device for controlling the amount of heat generated by the data driver, wherein the heat control device includes a heat pattern detector for determining whether the input image pattern is a heat image pattern, and a CS/inversion change in case of the heat image pattern A main control unit that generates and outputs one or more of information and driving voltage change information, and a CS that applies the target inversion method and the charge sharing mode to the data output signal applied to the data line according to the CS/inversion change information Provided is a display device comprising: a mode and inversion changer; and a driving voltage changer that generates a backlight compensation signal capable of compensating for a decrease in luminance according to the driving voltage change information and transmits the generated backlight compensation signal to a backlight controller.

According to an embodiment of the present invention, it is determined whether a certain region or more is a heating pattern that is expressed in the same grayscale and causes large heat generation, and in the case of such a heating image pattern, a charge-searing (CS) mode, an inversion method, and a driving voltage By changing one or more of the magnitudes of (Vdd), there is an effect of reducing heat generation in the data driving circuit.

In addition, among the first method of changing the combination of the charge-searing control mode and the inversion method with respect to a specific input image pattern, and the second method of reducing the driving voltage Vdd to a certain extent and compensating for the decrease in luminance with the backlight. By selectively applying one or more, there is an effect of minimizing heat generation in the data driving circuit without deterioration of image quality or power consumption.

1 shows an example of a heat dissipation structure of a driving circuit in a display device according to the related art.
2 is a block diagram for each function including the entire driving circuit unit of a display device to which the present invention can be applied.
3 shows an example of a charge-sharing circuit that can be used in the display device of the present invention.
4 is a table showing a waveform of a data output signal and a heating temperature according to a combination of a charge sharing mode and an inversion method in a liquid crystal display to which an embodiment of the present invention can be applied.
5 is a table showing a heating temperature according to the magnitude of a driving voltage or a transition voltage Vdd in a liquid crystal display to which an embodiment of the present invention can be applied.
6 is a functional block diagram of an apparatus for controlling heat in a display device according to a first embodiment of the present invention.
7 shows an example of CS/inversion identification information or CS/inversion change information that can be used in the first embodiment of the present invention.
8 is a functional block diagram of an apparatus for controlling heat in a display device according to a second embodiment of the present invention.
9 shows an example of driving voltage change information used in the second embodiment of the present invention.
10 is a functional block diagram of an apparatus for controlling heat generation of a display device according to a third embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to components of each drawing, the same components may have the same reference numerals as much as possible even though they are indicated in different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted.

In addition, in describing the components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, order, or number of the elements are not limited by the terms. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but other components may be interposed between each component. It will be understood that each component may be “interposed” or “connected”, “coupled” or “connected” through another component.

1 shows an example of a heat dissipation structure of a driving circuit in a display device according to the related art.

As shown in FIG. 1 , a typical liquid crystal display (LCD) includes an array substrate including a thin film transistor, which is a switching element for on/off control of each pixel region, a color filter and/or a black A display panel 110 including an upper substrate having a matrix, etc., a liquid crystal material layer formed therebetween, a driving circuit for controlling the thin film transistor, and a backlight unit providing light to the display panel (Back Light Unit) ; BLU; 130, etc., and the arrangement state of the liquid crystal layer is adjusted according to the electric field applied between the pixel (PXL) electrode and the common voltage (Vcom) electrode provided in the pixel area, and thus the transmittance of light is the device for which the image is displayed.

In the case of such a liquid crystal display device, there must be a backlight unit 130 that provides light from the outside, and such a backlight unit may include a light source, a light guide plate, a reflective plate, and sub-units such as an upper sheet, and mounting these sub-units. It includes one or more frames or chassis as a support structure for

Such a frame or chassis includes a cover bottom 140 that is a plate-shaped member supporting a part of the side and rear surfaces of the backlight unit, and a guide panel interlocking with the cover bottom to support between the backlight unit and the display panel. etc are used. In general, the cover bottom is formed of a metal material and the guide panel is formed of a plastic material, but is not limited thereto.

In addition, the case top 150 may be used as a frame for protecting the display panel by interlocking with the cover bottom and the guide panel and extending from the side of the display device to a part of the front surface of the display panel. The case top 150 is mainly formed in a plate-like structure made of a metal material.

In addition, the driving circuit for driving the display panel largely includes a gate driving circuit for providing a gate output signal to a gate line, a data driving circuit for controlling the data line, and the like. Typically, the gate driving circuit is installed inside the panel. The data driving circuit called D-IC and the entire system board or source printed circuit board (S-PCB) are disposed outside the display panel.

That is, as shown in FIG. 1 , the source PCB 160 is disposed on the rear surface of the cover bottom and the like, and a chip-on-film (COF), which is a kind of flexible connection circuit, to connect the source PCB to the display panel; 170)), and a data driving circuit (D-IC) 180 is disposed on a partial region of the COF.

Meanwhile, since a lot of heat is mainly generated in the data driving circuit (D-IC) 180 during operation of the display panel, a heat dissipation structure should be disposed near the D-IC 180 .

1 illustrates various types of mechanical heat dissipation structures used in such a conventional liquid crystal display device.

1, as a heat dissipation structure for dissipating heat generated from the conventional D-IC 180, as shown in FIG. A method of making contact with the side surface of the COF 170 on which is disposed, and forming an embossing structure that is a protrusion on a part of the inner surface of the metal case top 150 as shown in FIG. A method of contacting the COF surface where is located was used.

In addition, there is also a method of disposing a separate heat dissipation member such as an aluminum foam pad (AL Foam Pad) between the inner surface of the case top 150 and the surface of the COF 170, as shown in FIG. A method of directly attaching a heat dissipation tape such as an aluminum tape to the IC 180 has been used.

However, since the various heat dissipation methods shown in FIG. 1 are all mechanical mechanisms, they are inconvenient to install or have limitations in heat dissipation performance.

For example, in the method of FIGS. 1 (a) and (b), inaccurate matching between the position of the D-IC and the heat dissipation structure occurs during the mounting process, and thus the heat dissipation performance is reduced or the D-IC is pressed by Problems such as causing damage to the D-IC may occur.

In addition, in the method of attaching a separate aluminum heat dissipation member such as (c) of FIG. 1, a process of attaching such a heat dissipation member (aluminum foam pad and heat dissipation tape, etc.) is added, thereby reducing process and cost efficiency, aluminum tape, etc. There were disadvantages such as the possibility of damage to the adjacent COF during the attachment process.

The embodiment of the present invention is based on this point, and it is an object to provide a method for reducing heat generation of the data driving circuit (D-IC) in a circuit or software manner rather than in a conventional mechanical method.

That is, in the embodiment of the present invention, it is confirmed that the number of swings per unit time is directly related to the heat generation of the D-IC among various waveform shapes of the data output signal, and a specific image pattern that causes large heat in the D-IC, That is, heat generation of the D-IC is minimized by adjusting an inversion method or charge sharing mode that generates a data output signal when a heating image pattern is input.

In addition, in another embodiment of the present invention, as it is confirmed that the magnitude of Vdd, which is the driving voltage or high potential power voltage of the liquid crystal display device, is directly related to the heat generation of the D-IC, the Vdd value is changed when the heat generation image pattern is input. It is attempted to minimize the heat generation of the D-IC without reducing the luminance by decreasing it to a certain extent and increasing the light intensity of the backlight to a certain extent to compensate for the decrease in luminance.

Of course, in another embodiment of the present invention, in another embodiment of the present invention, there are two methods described above, namely, the first method of adjusting the inversion method and the charge sharing mode when inputting a heating image pattern, and the second method of reducing Vdd and compensating for the decrease in luminance with a backlight. It may be possible to apply them together by combining them.

The detailed configuration of the present invention will be described in more detail with reference to FIGS. 2 to 10 below.

2 is a block diagram for each function including the entire driving circuit unit of a display device to which the present invention can be applied.

Referring to FIG. 2 , a typical liquid crystal display device includes a display panel 210 including a display area 216 (active area; AA) in which a plurality of pixels P are formed, and a display panel for controlling display of each pixel of the display panel. It may include a system board 220 that is a printed circuit board (PCB) including a driving circuit for

The display panel 210 generally includes an array substrate as a lower substrate on which a plurality of gate lines, data lines, and thin film transistors are formed, and a color filter substrate as an upper substrate on which a color filter and a black matrix (BM) are formed, and therebetween. It is composed of a liquid crystal layer injected into the

In the display panel 210 , a plurality of pixels defined as an intersection region of the gate line GL and the data line DL are formed. That is, the data lines D1 to Dm and the gate lines G1 to Gn cross each other on the lower array substrate, and m Ⅷ n (m, n is a positive integer) liquid crystal cells Clc due to their cross structure. ) are formed in a matrix form, and k (k is a positive integer) number of dummy lines (not shown) may be further formed.

Each of the liquid crystal cells Clc includes a TFT, a pixel electrode 21 connected to the TFT, and a storage capacitor Cst. The liquid crystal cell Clc is driven by the voltage difference between the pixel electrode 21 that charges the data voltage by the driving voltage Vdd through the TFT and the common electrode 22 to which the common voltage Vcom is applied, and the incident light A display image corresponding to the image data DATA_RGB is realized by adjusting the transmittance amount.

Meanwhile, a black matrix, a color filter, and a common electrode are formed on the upper glass substrate of the display panel 210 . The common electrode 22 is formed on the upper glass substrate in the vertical electric field driving method such as the TN mode and the VA mode, and is formed on the lower glass substrate together with the pixel electrode 21 in the horizontal electric field driving method such as the IPS mode and the FFS mode. can be formed.

On the other hand, the gate driving circuit 13 for providing the gate output signal Vout to the gate line is formed of the display panel through a TFT array process according to a gate-in-panel (hereinafter referred to as 'GIP') method. It may be formed directly on the lower substrate.

The system board 220 may be connected to the display panel 210 through a flexible connection circuit such as a Tape Carrier Package (TCP) or a Chip-on-Film (COF) 217 , and the system board 220 . may be implemented in the form of a printed circuit board (PCB) including a timing controller 211 , a data driving circuit 212 , and the like.

The timing controller 211 may be expressed as T-Con, and a data control signal ( SDC) and a gate control signal GDC for controlling the operation timing of the gate driving circuit 213 to be provided to each driving circuit.

The data control signal SDC supplied from the timing controller 211 to the data driving circuit 212 includes a source start signal (Source, Start Pulse, SSP), a source sampling clock (Source Sampling Clock, SSC), and a source output enable signal. (Source Output Enable, SOE), and may include a polarity control signal (POL).

In the case of a liquid crystal display of a TFT using amorphous silicon as a material of a semiconductor layer, which is typically an active channel, the clock signal CLK is a pulse having an ON section width of 4 horizontal periods (H), and 8 clock signals ( CLK1 ~ CLK8) are used.

Here, the horizontal period or the horizontal period period expressed as "H" may be defined as an inverse number of a value obtained by multiplying the frame frequency by the number of gate lines. For example, if the display panel has a resolution of 1920*1080, the period of the horizontal section (H) is 15.4 μs, which is 1/(60Hz*1080).

The data driving circuit 212 may include a plurality of source driver ICs (D-ICs), and the data driving circuit itself may be expressed as a D-IC. Each of the source drive ICs samples and latches digital video data (DATA_RGB) input from the timing controller 211 in response to the data control signal SDC from the timing controller 211 and converts it into data of a parallel data system, Using it, a data output signal is generated and supplied to the data lines D1 to Dm.

On the other hand, in the liquid crystal display device applied to the present invention, a control method of varying the data output signal in various forms is applied to prevent deterioration of pixels or reduce power consumption. (Charge Sharing Control: CSC) technology.

Among them, the inversion technology is a technology that inverts the polarity of the data voltage in a constant unit to prevent flicker and improve image quality.

That is, in general, when an electric field of the same polarity is continuously applied to a liquid crystal capacitor in such a liquid crystal display device, the internal liquid crystal forming the liquid crystal capacitor deteriorates and a flicker phenomenon occurs. In order to prevent such flicker and improve image quality, an inversion driving method of inverting the polarity of the data voltage in a predetermined unit is used.

The inversion driving method may be classified into a frame inversion, a line inversion, a column inversion, a dot inversion, and the like according to a unit in which the polarity is inverted.

In the frame inversion driving method, the polarity of the data signal supplied to the pixels on the liquid crystal panel is inverted in units of frames according to the polarity control signal POL. The frame inversion driving method has the advantage of being driven with low power consumption compared to other driving methods. However, the frame inversion method has a problem in that a flicker phenomenon occurs in units of frames.

The low line inversion driving method inverts the polarity of the data signal supplied to the pixels on the liquid crystal panel in units of one horizontal line and one frame according to the polarity control signal POL. The low-line inversion driving method has a problem in that a flicker such as a stripe pattern occurs between horizontal lines due to a difference in luminance between pixels in a vertical direction.

In the column line inversion driving method, the polarity of the data signal supplied to the pixels on the liquid crystal panel is inverted in units of data lines and units of frames according to the polarity control signal POL. In the column inversion driving method, a flicker phenomenon such as a stripe pattern may occur between vertical lines due to a luminance difference generated between pixels in a horizontal direction.

The dot inversion driving method changes the polarity of the data signal for every k pixels (k=1.2…). When k is 1, it is called a 1-dot inversion driving method, and when k is 2, it is called a 2-dot inversion driving method. It is called the driving method.

For example, in the 1-dot inversion driving method, the polarities of the data signals supplied to the pixels on the liquid crystal panel are opposite to each other according to the polarity control signal POL, and the polarities of the data signals supplied to the pixels on the liquid crystal panel are inverted in a frame-by-frame unit. In the version driving method, the polarity of the data signal supplied to the pixels on the liquid crystal panel is inverted so that it is opposite to all of the pixels adjacent in the horizontal and vertical directions in units of two lines and inverted in units of frames according to the polarity control signal POL.

The one-dot and two-dot inversion driving method provides an image with superior image quality compared to other inversion methods by canceling flicker generated between frames. However, the 1-dot inversion method or the 2-dot inversion method has a disadvantage in that power consumption is large because the polarity of the data signal is inverted in each horizontal section, and a charge-sharing technique may be used to solve the power consumption problem.

3 shows an example of a charge-sharing circuit that can be used in the display device of the present invention.

The charge-sharing technology basically turns on the charge-share switch SW1 connected between adjacent output channels (ie, adjacent data line output terminals) of the data driving circuit during the high logic period of the source output enable signal SOE. It is a technology that changes the initial output level of the data driving circuit to an intermediate level by sharing positive and negative charges.

Looking at this charge-sharing circuit in more detail, as shown in FIG. 3 , the charge-sharing circuit 300 includes a plurality of first switching elements SW1 connected to the output buffer 320 and the data lines D1 to Dm, A plurality of switching elements SW2 connected between the data lines D1 to Dm are provided. Each of the first switching elements SW1 is turned on only in the low section of the source output enable (SOE) signal to transmit the positive or negative data signal supplied from the output buffer 320 to each of the data lines D1 to Dm. supply The second switching element SW2 is turned on only in the high section of the source output enable signal SOE to commonly connect the data lines D1 to Dm. The charge-sharing circuit 300 supplies a voltage between the positive polarity data signal and the negative polarity data signal to control the voltage supplied to the data lines D1 to Dm so that the voltage fluctuation of the data lines D1 to Dm is not large. do. Accordingly, the charge-sharing circuit 300 reduces the voltage fluctuation range of the data lines D1 to Dm, thereby reducing power consumption.

On the other hand, the charge-sharing control is a CS mode (first mode) in which charge-sharing is always applied every horizontal period, and a CSC mode in which charge-sharing is performed only when the polarity of the polarity control signal (POL) is changed for each detailed operation method. (second mode), and a USC (Unique Charge Share) mode (third mode) in which charge sharing is performed only with the same polarity.

4 is a table showing a waveform of a data output signal and a heating temperature according to a combination of a charge sharing mode and an inversion method in a liquid crystal display to which an embodiment of the present invention can be applied.

In general, power consumption P in the data driving circuit D-IC may be expressed as Equation 1 below.

In Equation 1, the first term on the right corresponds to dynamic power, and the second term corresponds to static power. _{Among them, f LINE, which} is one of the parameters determining the dynamic power, is a variable value depending on the above-described inversion method of the data line output and the charge sharing mode.

On the other hand, when the data output voltage waveform is changed according to the inversion method and the charge sharing mode, the dynamic power is changed accordingly and the amount of heat generated in the D-IC is also changed.

4 shows the heat generation temperature in the D-IC when the data output voltage waveform is changed according to the inversion method and the charge-sharing mode. The amount of heat generated by the D-IC is proportional to the number of swings per unit time in the data output voltage waveform. do.

That is, in the table of FIG. 4 , the leftmost field indicates the inversion method and exemplifies the column inversion method and the vertical 2-dot inversion method (V2dot), and the second field indicates the charge sharing mode and does not perform charge sharing. No-CS mode or Hi-Z mode (that is, high impedance mode), CS mode (first mode) in which charge sharing is always applied every horizontal period, and charge sharing only when the polarity of the polarity control signal (POL) is changed CSC mode (second mode) for performing

The third field in the table of FIG. 4 shows the waveform of the data output signal according to the corresponding inversion method and the charge-sharing mode, and in particular, the swing in the data output signal waveform is indicated.

On the other hand, the fourth field indicates the number of swings present in the waveform of the data output signal according to the inversion method and the charge-sharing mode corresponding to each second, and the fifth to eighth fields indicate the measurement value of the heating temperature at that time.

As shown in FIG. 4 , it can be seen that the heating temperature is also increased so that the number of swings present in the data output waveform per unit time increases.

5 is a table showing a heating temperature according to the magnitude of a driving voltage or a transition voltage Vdd in a liquid crystal display to which an embodiment of the present invention can be applied.

Among the power consumption of Equation 1, there is a Vtransition parameter among components representing dynamic power, and this Vtransition parameter is Vdd, which is a driving voltage or a transition voltage.

Accordingly, as the driving voltage or transition voltage Vdd increases, power consumption and current consumption increase as well as the smoke temperature as shown in FIG. 5 .

On the other hand, for screen adjustment, etc. in the display panel test process or TV broadcasting process, a full-color screen displayed with the same color or gradation in the entire panel or a significant area or image data of two gradations is repeatedly displayed by repeating a certain space A stripe screen or the like may be provided.

In general video data, etc., the input image pattern is momentarily changed and the inversion method or the charge-sharing mode is changed accordingly, so that when viewed as a whole, the amount of heat is averaged so that the amount of heat does not increase more than a certain amount. However, if an image of the same constant pattern is continuously displayed, such as a full-color image pattern or a strike image pattern, if the data output waveform applied at that time is a pattern showing a large amount of heat, the D-IC The amount of heat generated becomes too large, and there is a risk of damage to the circuit or the like.

That is, when a heating image pattern such as a full-color (Full-Green, Full-Red, Full-Blue, Full-White) input image pattern is input, it is necessary to adjust the data output voltage waveform to prevent damage due to heat generation. there will be

6 is a functional block diagram of an apparatus for controlling heat in a display device according to a first embodiment of the present invention.

The first embodiment of the present invention is based on a basic principle of applying the inversion method and the charge-sharing mode (CS mode) variably to minimize the D-IC heat generation when a heating image pattern is input.

As shown in FIG. 6 , the heating control device 600 according to the first embodiment of the present invention includes a display panel including a plurality of pixels defined by an intersection region of a gate line and a data line, and a data line according to an input image pattern. A heating control device used in a display device including a data driving unit that generates and provides a data output signal, and largely includes a heating pattern detection unit 610 , a main control unit 620 , and a CS mode and inversion change unit 630 . can be configured.

In addition, the heat control device 600 according to the first embodiment of the present invention has a CS/inversion change information storage unit in which CS/inversion identification information for a combination of each inversion method and difference sharing mode is matched and stored. 640 and the heating information storage unit 650 for storing heating information for a combination of each inversion method and the differential sharing mode may be optionally further included.

The heating pattern detector 610 analyzes an input image pattern or digital video data DATA_RGB input through a timing controller or the like to determine whether the input image is a heating image pattern.

The heating image pattern refers to a specific image pattern that generates large heat in the data driving circuit (D-IC), for example, a full-color image pattern that displays image data of the same grayscale and color on the entire display panel There is a stripe image pattern in which image data of two grayscales is repeatedly displayed at intervals.

Full-color image patterns include Full Black Pattern, Full White Pattern, Full Green Pattern, Full-Red Pattern, and Full Blue Pattern. It may be a pattern, and the stripe image pattern may be a stripe image pattern in which white and black are repeatedly expressed in a stripe form at regular intervals.

In addition, the heating image pattern may include a so-called L80 pattern, which is a data pattern having a white area of 64% and a black area of 36% compared to the effective display area (X*Y).

On the other hand, when the display panel is operated in a normally white mode such as the TN mode and the VA mode (the larger the difference between the data voltage and the common voltage, the lower the gray scale), the amount of heat generated by the data driving circuit is full-black. Very large in the pattern. On the other hand, when the liquid crystal display panel is operated in a normally black mode such as the IPS mode and the FFS mode (the larger the difference between the data voltage and the common voltage, the higher the grayscale), the power consumption of the data driving circuit is full. It can be very large in the white pattern and the L80 pattern.

As described below, since the heat image pattern with high heat generation may be different depending on the shape or structure of the display panel, heat information on the combination of all inversion methods and differential sharing modes applied to the corresponding display panel, as will be described below. may be stored in the fever information storage unit 650 and referenced thereto.

In addition, the heating pattern detecting unit 610 may determine that the heating image pattern is detected even when the above-described heating image pattern appears on the entire display panel as well as on the display panel area having a specific ratio or more. For example, it is determined that the heating image pattern is detected when the above-described full-color pattern is displayed on 50% or more of the entire display panel.

In addition, the heating pattern detecting unit 610 may determine that the digital video data DATA_RGB input from the outside, such as a timing controller, is a heating image pattern immediately at a predetermined point in time when the above-described specific heating image pattern is identified, but such an image pattern If this is continuously expressed for a predetermined time or more, it may be determined that the fever image pattern is detected.

That is, when the heating image pattern is immediately changed to another image pattern even when the heating image pattern is input, or when the heating image pattern lasts for a short time, the effect on the heating of the data driving circuit, etc. is small, and therefore, heating control according to the embodiment of the present invention because you don't have to do it.

When it is determined that the input image pattern is a heating image pattern, the heating pattern detection unit 610 generates a heating image pattern detection signal and outputs it to the main control unit 620 .

The main control unit 620 generates CS/inversion change information indicating the heating image pattern detection signal from the heating pattern detection unit 610 as a target inversion method capable of reducing heat generation of the data driver and a charge-sharing mode to generate the CS mode. and outputting to the inversion change unit 630 .

Then, the CS mode and inversion change unit 630 receives the CS/inversion change information and applies the target inversion method and the charge sharing mode to the data output signal applied to the data line accordingly to the data driving circuit, etc. To reduce the amount of heat generated.

At this time, the main control unit 620 may refer to information stored in the heating information storage unit 650 , check the data output waveform based on the current heating image pattern and the amount of heating according to the current heating image pattern, and then determine whether heating control is required.

The heat information storage unit 650 is a storage means for storing heat information for a combination of each inversion method and difference sharing mode, and may be, for example, an EEPROM in which table information as shown in FIG. 4 is stored, but is limited to the form. no.

For example, in the current state where the heating image pattern is being input, the inversion method and difference sharing mode are each a vertical 2 dot inversion (V2dot) method, and charge sharing is performed only when the polarity of the polarity control signal (POL) is changed. In the CSC mode (the second mode), the heating temperature at that time is about 90 degrees or less, so that it can be determined that there is no need to control the heating.

However, when it is determined that the heating temperature exceeds 102 degrees because the inversion method and difference sharing mode in the state in which the heat image pattern is input are V2dot and CS mode (first mode), respectively, for example, the target inversion method and generating CS/inversion change information so that the charge sharing mode can be changed to the column inversion and non-CS mode (ie, Hi-Z mode), respectively, and outputting the CS/inversion change information to the CS mode and inversion changer 630 . .

On the other hand, the main control unit 620 does not consider only the amount of heat generated or the heat generation temperature, but determines whether to change the CS/inversion in consideration of power consumption, luminance, image quality, and the like.

That is, the main control unit 620 is not worse in terms of image quality, luminance, power consumption, pixel deterioration, etc. when changing to the specific CS mode and the inversion method even when the specific CS mode and the inversion method minimize the amount of heat generated. , may not change to the specific CS mode and inversion method.

Therefore, the main control unit 620 refers to the above-described heating information storage unit 650, and only when the heating temperature by the current heating image pattern exceeds a specific threshold temperature value such as 100 degrees, the CS mode and the inversion method are performed. You can decide to change.

Meanwhile, the aforementioned CS/inversion change information is information indicating the target inversion method and CS mode to be changed by the main controller 620 , and the main controller 620 generates CS/inversion change information to generate CS/inversion change information. The /inversion change information storage unit 640 may be referred to.

The CS/inversion change information storage unit 640 may be a storage means or storage medium, such as an EEPROM, in which CS/inversion identification information for a combination of each inversion method and differential sharing mode is matched and stored.

The CS/inversion identification information stored in the CS/inversion change information storage unit 640 or the CS/inversion change information generated by the main control unit can express the inversion method and CS mode of the display panel to be changed. It may be more than bits of information, but the form is not limited.

7 is an example of CS/inversion identification information or CS/inversion change information that can be used in the first embodiment of the present invention. (b) of 7 exemplifies a case in which 2-bit information is displayed.

Referring to FIG. 7A , the CS/inversion change information used in the first embodiment of the present invention may include 2-bit information indicating the CS mode and 2-bit information indicating the inversion method.

According to the example of FIG. 7A , the CS/inversion change information is 4-bit information, and when '0001' indicates a non-CS mode (Hi-Z mode) and a column inversion method, '1011' This indicates the CSC mode (the second mode) and the vertical 2-dot inversion (V2dot).

Of course, the order of 2 bits of CS information and 2 bits of information indicating the inversion method may be changed. it could be

Also, in FIG. 7B, as an example of CS/inversion change information displayed with a smaller amount of information, 1 indicating current CS mode maintenance or CS deactivation (ie, non-CS mode Hi-Z mode) Bit information and 1-bit information indicating conversion to maintaining current inversion or column inversion may be configured.

That is, if the CS/inversion change information is “11”, it indicates to keep the current CS mode and inversion method as it is, and if ‘00’, it indicates to change to the non-CS mode (Hi-Z mode) and the column inversion method. to dictate that

Of course, the form of the CS/inversion change information is not limited to the above case, and other forms may be possible as long as it can represent each combination of all CS modes and inversion methods applied to the display panel.

As described above, according to the first embodiment of the present invention shown in FIGS. 6 and 7, when a heating image pattern that causes large heat is input to the data driving circuit, the heating control device does not affect the image quality. By changing the CS mode and the inversion method to minimize the degree of heat generation, it is possible to prevent thermal damage to the data driving circuit or other display panel elements.

8 is a functional block diagram of an apparatus for controlling heat in a display device according to a second embodiment of the present invention.

In the second embodiment of the present invention, when a heating image pattern is input, the Vdd value, which is the data driving voltage or high potential power voltage, is reduced to minimize D-IC heat generation, and the light intensity of the backlight is compensated for the decrease in luminance. The basic principle is to increase

As shown in FIG. 8 , the heat control device 800 according to the second embodiment of the present invention is a heat control device used in the display device as described in the first embodiment, and determines whether an input image pattern is a heat image pattern. It may include a pattern detection unit 810 , a main control unit 820 , and a driving voltage change unit 830 , and may further include a driving voltage change information storage unit 840 .

Since the heating pattern detecting unit 810 is the same as described in the first embodiment, a detailed description will be omitted to avoid duplication.

In the second embodiment, when the main controller 820 receives a heating image pattern detection signal from the heating pattern detection part 810, the driving indicating the reduction amount of the driving voltage Vdd of the display panel to reduce the heat of the data driver. It performs a function of generating voltage change information and outputting it to the driving voltage changing unit 830 .

In addition, the driving voltage change unit 830 receives the driving voltage change information from the main controller 820, applies the reduced driving voltage to driving the display panel, and generates a backlight compensation signal capable of compensating for the decrease in luminance. It performs a function of transmitting to the backlight control unit 850 .

That is, the heating control device according to the second embodiment of the present invention shown in FIG. 8 uses the characteristic that the heating temperature also decreases as the driving voltage Vdd of the display panel decreases as shown in FIG. When the heating image pattern is input, the driving voltage Vdd of the display panel is decreased to a certain extent. On the other hand, when the driving voltage Vdd is reduced, the luminance is also reduced. In order to compensate for this, the backlight intensity is increased.

In this case, the backlight compensation signal output from the driving voltage changing unit 830 to the backlight controller 850 may be width information or duty cycle information of a pulse width modulation signal PWM for controlling backlight intensity.

In addition, the heating control device 800 according to the second embodiment may further include a driving voltage heating information storage unit for storing heating information compared to a driving voltage as shown in FIG. 5 indicating an amount of heating according to the driving voltage.

When the heating image pattern is input, the main control unit 820 refers to the above-described driving voltage heating information storage unit, and sets the current driving voltage to the maximum value of the driving voltage that does not exceed the heating temperature that the data driving circuit can tolerate. The driving voltage change information is generated to decrease the driving voltage and output to the driving voltage changing unit 830 .

For example, when a heating image pattern is input while the current driving voltage is 16.7V, if the limit temperature allowed for the data driving circuit is 110 degrees, as shown in FIG. 5, the driving voltage is controlled to be 15V. will be.

Also, the heat generation control device 800 according to the second embodiment of the present invention may further include a driving voltage change information storage unit 840 for storing information on the driving voltage reduction amount and the backlight compensation amount accordingly.

In the present specification, the driving voltage is a potential value in contrast to the common voltage Vcom among voltage levels used for driving the display panel, and is expressed in other expressions such as a high potential power supply voltage, a transition voltage, and a reference voltage Vref. can be used

9 shows an example of driving voltage change information used in the second embodiment of the present invention.

9 , the driving voltage change information used in the second embodiment may include, but is not limited to, 1 bit of the driving voltage reduction activation flag and 2-3 bits of information indicating the degree or amount of reduction in the driving voltage. .

That is, according to the example of FIG. 9 , the driving voltage change information is 4-bit information, and if the first bit is 0, it means to keep the current driving voltage as it is, and if '1001', the driving voltage is reduced by 0.5V and the backlight intensity (backlight signal) pulse width) may mean controlling to increase by 5%.

Of course, unlike FIG. 9 , for example, if '000', the driving voltage may be maintained, and the degree of decreasing the driving voltage at regular intervals from '001 to 111' and increasing the backlight intensity may be displayed.

As described above, according to the second embodiment of the present invention shown in FIGS. 8 and 9, when a heating image pattern that generates large heat is input to the data driving circuit, the heating control device reduces the driving voltage Vdd to a certain extent. By increasing the backlight intensity to compensate for the decrease in luminance while minimizing the degree of heat generation, it is possible to prevent thermal damage to the data driving circuit or other display panel elements without affecting image quality or luminance.

10 is a functional block diagram of an apparatus for controlling heat generation of a display device according to a third embodiment of the present invention.

The third embodiment of the present invention is based on a basic principle of simultaneously applying the CS/inversion change according to the first embodiment and the driving voltage reduction control according to the second embodiment.

That is, as shown in FIG. 10 , the heating control apparatus 1000 according to the third embodiment of the present invention includes a heating pattern detector 1010 that determines whether an input image pattern is a heating image pattern, a main controller 1020 , and a CS mode. and an inversion change unit 1030 and a driving voltage change unit 1040 , and may further include a CS/inversion change information storage unit 1050 and a driving voltage change information storage unit 1060 . .

Among the configurations of the third embodiment, the heating pattern detection unit 1010 , the CS mode and inversion change unit 1030 , the driving voltage change unit 1040 , the CS/inversion change information storage unit 1050 , and the driving voltage change information Since the storage unit 1060 is the same as the corresponding components described in the first and second embodiments described above, detailed descriptions are omitted to avoid duplication.

In the third embodiment, the main controller 1020 may simultaneously perform two controls of changing the CS/inversion or reducing the driving voltage by comprehensively considering image quality, luminance, power consumption, pixel deterioration, and the like.

That is, if only one method of changing the CS/inversion or reducing the driving voltage according to the first and second embodiments is applied, there is a limit in reducing the amount of heat, or if other problems such as deterioration of image quality occur even though the amount of heat is reduced, there are two methods. The control method is applied simultaneously with a constant weight.

For example, when a thermal image pattern is input, if other problems such as image quality deterioration occur by changing to a specific CS/inversion method to reduce the heating temperature, change to another CS/inversion method with less image quality deterioration At the same time, a control for reducing the driving voltage to a certain degree can be simultaneously performed.

Accordingly, the main control unit 1020 according to the third embodiment simultaneously generates at least one of CS/inversion change information and driving voltage change information, and generates a CS mode and inversion change unit 1030 and a driving voltage change unit 1040, respectively. ), and the CS mode and inversion changing unit 1030 and the driving voltage changing unit 1040 change the CS/inversion method according to the change information and perform control to reduce the driving voltage.

As described above, according to the third embodiment of the present invention, the influence on image quality, luminance, power consumption, pixel deterioration, etc. is minimized by simultaneously performing CS/inversion change or driving voltage reduction control according to the first and second embodiments. while reducing the amount of heat generated by the data driving circuit.

The heating pattern sensing unit, main control unit, CS mode and inversion changing unit, and driving voltage changing unit used in each of the above embodiments are hardware including certain circuit elements, circuit chips, and circuit components such as comparators. It may be implemented, but is not limited thereto, and may be implemented as software implemented in a certain chipset (Chip Set).

In addition, the heat control device according to each embodiment of the present invention may be basically configured to be included in the data driving circuit (D-IC), but in some cases, the inside of the timing controller, the inside of the gate driving circuit, the inside of the touch driving circuit, etc. It may be included in all circuit units constituting the display device.

As described above, according to an embodiment of the present invention, when a heating image pattern that causes a large amount of heat is input to the data driving circuit of the display panel, the amount of heat is reduced by changing the combination of the inversion method and the charge sharing (CS) mode. This has the effect of minimizing thermal damage to the display device.

In addition, when a heating image pattern that causes large heat generation is input to the data driving circuit of the display panel, etc., the amount of heat generated by decreasing the driving voltage Vdd to a certain extent is reduced, and the resulting decrease in luminance is compensated by increasing the backlight light intensity. However, it has the effect of reducing the amount of heat generated by the data driving circuit without changing the image quality.

In addition, a first method of changing a combination of a charge sharing (CS) mode and an inversion method for a specific heating image pattern input, and a method of reducing the driving voltage (Vdd) to a certain extent and compensating for the decrease in luminance with a backlight By selectively applying one or more of the two methods, there is an effect of minimizing heat generation in the data driving circuit without deterioration of image quality or power consumption.

The above description and the accompanying drawings are merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains can combine the configuration within a range that does not depart from the essential characteristics of the present invention. , various modifications and variations such as separation, substitution and alteration will be possible. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

600, 800, 1000: Heat control device
610, 810, 1010: Heating pattern detection unit
620, 820, 1020: main control unit
630, 1030: CS mode and inversion change part
830, 1040: drive voltage change part

Claims (13)

a display panel including a plurality of pixels defined by a cross region of a gate line and a data line;
a data driver generating and providing a data output signal to the data line according to an input image pattern;
a heat control device for controlling the amount of heat generated by the data driver;
Including, the heat control device,
A fever pattern detection unit for determining a fever image pattern;
a main control unit for generating and outputting CS/inversion change information including information on a CS mode to be changed and information on an inversion method to be changed when a fever image pattern is input;
A display device comprising: a CS mode and inversion changer configured to apply a target inversion method and a charge sharing mode to a data output signal applied to the data line according to CS/inversion change information. According to claim 1,
The CS/inversion change information indicates a target inversion method and a charge sharing mode capable of reducing heat generation of the data driver. According to claim 1,
A display device further comprising a CS/inversion change information storage unit in which CS/inversion identification information for a combination of all inversion methods and differential sharing modes is matched and stored. According to claim 1,
The information on the to-be-changed CS mode is 1-bit or 2-bit information indicating the to-be-changed CS mode, and the information on the to-be-changed inversion scheme is 1-bit or 2-bit information indicating the to-be-changed inversion scheme. According to claim 1,
A display device further comprising a heat information storage unit for storing heat information for a combination of all inversion methods and car sharing modes. According to claim 1,
The heating image pattern is a full-color pattern or a stripe pattern,
The heating pattern detecting unit determines that the heating image pattern is detected when the heating image pattern is continuously expressed over a predetermined region of the display panel for a predetermined time or more. a display panel including a plurality of pixels defined by a cross region of a gate line and a data line;
a data driver generating and providing a data output signal to the data line according to an input image pattern;
a heat control device for controlling the amount of heat generated by the data driver;
Including, the heat control device,
A fever pattern detection unit for determining a fever image pattern;
a main control unit generating and outputting driving voltage change information including information indicating a degree of a decrease in driving voltage Vdd when the heating image pattern is input;
and a driving voltage changing unit generating a backlight compensation signal capable of compensating for a decrease in luminance according to the driving voltage change information and transmitting the generated backlight compensation signal to the backlight control unit. 8. The method of claim 7,
The driving voltage change information indicates a decrease amount of the driving voltage Vdd of the display panel to reduce heat generation of the data driving unit. 8. The method of claim 7,
and a driving voltage change information storage unit configured to store information on the driving voltage reduction amount and the backlight compensation amount accordingly. 8. The method of claim 7,
The driving voltage change information includes 1-bit information of the driving voltage reduction activation flag,
The information indicating the degree of the driving voltage decrease is 2 to 3 bits of information. 8. The method of claim 7,
The heating image pattern is a full-color pattern or a stripe pattern,
The heating pattern detecting unit determines that the heating image pattern is detected when the heating image pattern is continuously expressed over a predetermined region of the display panel for a predetermined time or more. a display panel including a plurality of pixels defined by a cross region of a gate line and a data line;
a data driver generating and providing a data output signal to the data line according to an input image pattern; and,
a heat control device for controlling the amount of heat generated by the data driver;
Including, the heat control device,
A fever pattern detection unit for determining a fever image pattern;
a main control unit for generating and outputting at least one of CS/inversion change information and driving voltage change information when the heating image pattern is input;
a CS mode in which a target inversion method and a charge sharing mode are applied to a data output signal applied to the data line according to the CS/inversion change information including information on the CS mode to be changed and information on the inversion method to be changed; and an inversion changer, and
A display device comprising: a driving voltage changing unit for generating a backlight compensation signal capable of compensating for a decrease in luminance according to the driving voltage change information including information indicating a degree of a driving voltage decrease amount, and transmitting the generated backlight compensation signal to the backlight control unit. 13. The method of claim 12,
The CS/inversion change information indicates a target inversion method and a charge sharing mode to reduce heat generation of the data driver, and the driving voltage change information indicates an amount of decrease in the driving voltage Vdd of the display panel. Device.

Images