KR100480150B1 - Method and apparatus for controlling data - Google Patents

Abstract

The present invention relates to a data control method and apparatus for reducing power consumption and heat generation of a data driving circuit.

The data control method and apparatus according to the present invention detect a temperature of a data driving circuit for supplying data to a plurality of data wires, and if the detected temperature is higher than a preset temperature, the data control method and apparatus are equal to a data area of a predetermined size adjacent to the data. Copy the data.

Description

Data control method and apparatus {METHOD AND APPARATUS FOR CONTROLLING DATA}

The present invention relates to a data control method, and more particularly, to a data control method and apparatus for reducing power consumption and heat generation of a data driving circuit.

Recently, there is a growing interest in flat panel displays that can reduce the large weight and volume of cathode ray tubes. Such a flat panel display includes a liquid crystal display (hereinafter referred to as "LCD"), a plasma display panel (hereinafter referred to as "PDP"), a field emission display (hereinafter referred to as "PDP"). FED ", and electroluminescence (hereinafter referred to as" EL "), and the like, and supply digital signals or analog data to the display panel.

Among such flat panel displays, the PDP emits phosphors by 147 nm ultraviolet rays generated when the He + Xe or Ne + Xe inert mixed gas is discharged to display an image including characters or graphics. Such a PDP is not only thin and easy to enlarge, but also greatly improved in quality due to recent technology development. In particular, the three-electrode AC surface discharge type PDP has advantages of low voltage driving and long life because wall charges are accumulated on the surface during discharge and protect the electrodes from sputtering caused by the discharge.

The PDP is driven by dividing one frame into several subfields with different number of flashes in order to express the gray level of an image. Each subfield is further divided into a reset period for uniformly generating discharge, an address period for selecting a discharge cell, and a sustain period for implementing gray levels according to the number of discharges. When the image is to be displayed with 256 gray levels, the frame period (16.67 ms) corresponding to 1/60 second is divided into eight subfields SF1 to SF8 as shown in FIG. Each of the eight subfields SF1 to SF8 is divided into a reset period, an address period, and a sustain period. The reset period and the address period of each subfield are the same for each subfield, while the sustain period and the number of discharges thereof are 2 ⁿ in each subfield (where n = 0,1,2,3,4,5,6, 7) is increased in proportion. In this way, since the sustain period is changed in each subfield, the gray level of the image can be expressed.

However, the PDP has a large power consumption because the driving voltage is relatively high due to the discharge characteristics causing the discharge between the two electrodes and the large panel size. In addition, a drive integrated circuit (hereinafter, referred to as 'IC') for driving the data electrode and the scan electrode of the PDP has to supply a high voltage to each of the electrodes Y, Z, and X in order to cause discharge. Power consumption is big and heat generation is big.

Most of the power consumption of the PDP is consumed in the sustain period, and then much in the subsequent address period. For example, the sustain period requires several hundred watts of power, and the address period requires tens of watts of power. The power consumption during the sustain period is mainly increased by the efficiency of the PDP. The power consumption in the address period is increased or decreased in accordance with the capacitance value C of the PDP, the voltage V, and the switching frequency of the drive IC.

As shown in FIG. 2, the capacitance C of the PDP includes the capacitance C1 between the data electrodes X1 to Xn, and the capacitance C2 between the data electrodes X1 to Xn and the scan electrodes Y1 to Ym. And the capacitance C3 between the scan electrodes Y1 to Ym and the common sustain electrode Z, and the capacitance C4 between the address electrode X and the common sustain electrode Z. More than 90% of the power consumption in the address period is generated by the displacement current generated during charging / discharging of the PDP. In the power consumption of the address period, the power consumption generated by the displacement current can be expressed by Equation 1 below.

Where I is the current, V is the voltage of the data pulse, C is the capacitance value between the address electrode X and the other electrodes Y and Z adjacent thereto, f is the frequency, and average switching per unit time of the data drive IC. The number of times.

When the energy recovery circuit is employed in the data drive IC in this manner, the power consumption of the data drive IC can be expressed by Equation (2).

Where α represents the energy recovery efficiency by the energy recovery circuit. In the data drive IC, the energy recovery efficiency α is about 0.5 at most.

As can be seen from Equations 1 and 2, in order to reduce the power consumption of the address period, a method of lowering the displacement current (I) by lowering the number of charge / discharge cycles, a method of lowering the data voltage (V), and the capacitance of the PDP ( There is a method of lowering C) and a method of reducing the number of times f of the data drive IC. However, the method of lowering the data voltage (V) is limited because it is a voltage that can cause discharge in the discharge cell, and there is a limit in reducing the capacitance of the PDP in that the PDP is aimed at high resolution / large screen size. In addition to these methods, there is a method of recovering reactive power from the PDP and adding an energy recovery circuit to the data drive IC for supplying the voltage recovered using the resonant circuit to the PDP before the data holding voltage is supplied.

The capacitance C of the PDP, i.e., the condition under which the load is maximum, is when a data pattern having a large voltage difference between adjacent discharge cells is input, and among these data patterns, high logic and low logic are shown in both the column direction and the low direction. It is when the alternate switching data pattern is input as shown in 3.

The number of times f of switching of the data drive IC is maximum in the above-described switching data pattern. This is because the switching data pattern has different logic values of vertically adjacent discharge cells, so that the switching elements of the data drive IC are repeatedly turned on and off every horizontal period. In other words, the maximum number of switching f of the data drive IC per address electrode X in one frame period is the number of scan lines (= scan electrode or common sustain electrode) x the number of subfields. The switch element must repeat on / off every scan in the subpixel switching pattern. For example, if the resolution is VGA and one frame contains 8 subfields, then 480 (scanline) × 8 = 3840 times, and if one frame includes 12 subfields, 480 × 12 = It's 5760 times.

As can be seen from the above, in the switching data pattern or the similar data pattern, the capacitance of the PDP and the number of switching of the data drive IC are increased so that the displacement current is increased so that the power consumption and heat generation amount of the data drive IC are large. do.

Accordingly, it is an object of the present invention to provide a data control method and apparatus for reducing power consumption and heat generation of a data driving circuit.

In order to achieve the above object, the data control method according to the present invention comprises the steps of sensing the temperature of the data driving circuit for supplying data to a plurality of data wirings; If the sensed temperature is higher than a preset temperature, copying the same data to a data area of a predetermined size adjacent to the data to lower the resolution of the data.

A data control device according to the present invention includes a data driving circuit for supplying data to a plurality of data wires; A temperature sensor for sensing a temperature of the data driving circuit; If the sensed temperature is higher than the preset temperature, the data conversion circuit for reducing the resolution of the data by copying the same data to a data area of a predetermined size adjacent to the data.

delete

The data conversion circuit may reduce the resolution of the data when the sensed temperature is higher than a preset temperature.

The data conversion circuit may perform data conversion on at least one or more subfields having a low luminance weight.

The data conversion circuit alternately performs data conversion in units of subfields in at least one or more subfields having low luminance weights.

The data conversion circuit performs data conversion on all subfields included in one frame.

The data conversion circuit is characterized by performing data conversion by alternating by subfield group units including at least two subfields.

The data conversion circuit alternately performs data conversion in units of one frame period.

The resolution is reduced by the data conversion circuit from 1 × 1 resolution to 3 × 3 resolution.

The data conversion circuit detects a number of inverting data values between adjacent data in the vertical direction and the horizontal direction, and compares the inversion number of the data with a preset reference value. When the inversion number of the data is larger than the reference value, the resolution of the data is increased. It is characterized by lowering.

Other objects and features of the present invention in addition to the above object will become apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 4 to 12.

The data control method and apparatus according to the present invention can reduce the power consumption and heat generation of the data driver IC by lowering the resolution of the input data. Such a data control method and apparatus can be applied to all digital flat panel display devices. 4 and 7 show an example in which the data control method and apparatus of the present invention are applied to a driving device of a PDP.

Referring to FIG. 4, the driving apparatus of the PDP according to the present invention includes a data driver 49 for driving the address electrode X of the PDP 50 and a scan electrode Y for the PDP 50. A scan / sustain driver 51, a common sustain driver 52 for driving the common sustain electrode Z of the PDP 50, a timing controller 47 for controlling the drive timing of the PDP 50, Alignment of data by the automatic gain control unit 42, the error diffusion unit 43, the subfield mapping unit 44, the frame memory 45, and the drive IC connected between the gamma correction unit 41 and the data driver 49. A unit 46 and a data converter 48 and a temperature sensor 53 connected to the data converter 48 are provided.

The data driver 49 includes a plurality of data drive ICs connected to a predetermined number of address electrodes X to supply data to the address electrodes X, respectively.

The scan driver 51 is connected to the scan electrodes Y to supply a reset pulse (or setup pulse) to the scan electrodes Y at the same time. In addition, the scan driver 51 sequentially supplies the scan pulses to the scan electrodes Y in the address period, and then simultaneously supplies the sustain pulses to the scan electrodes Y in the sustain period.

The sustain driver 52 is commonly connected to the sustain electrodes Z to supply the sustain pulses to the sustain electrodes Z at the same time.

The timing controller 47 receives the vertical / horizontal synchronization signals H and V to generate timing control signals. The timing controller 47 outputs the timing control signals by the data alignment unit 48, the data driver 49, and the scan driver for each drive IC. 51 and the sustain driver 52 to control the driving timing of the PDP 50.

The gamma correction unit 41 performs gamma correction on the video signal to linearly convert the luminance value according to the gray value of the video signal.

The automatic gain adjuster 42 converts the gray scale range of the input data RGB into a preset gray scale range according to the luminance information from the gamma corrector 41 to uniformly compensate the gain of the input data.

The error diffusion unit 43 serves to finely adjust the luminance value by diffusing the error component to adjacent cells. To this end, the error diffusion unit 43 separates the data into the integer and the fractional part and multiplies the fractional part by a Fly-Steinberg coefficient to spread the error in adjacent cells.

The subfield mapping unit 44 maps data from the error diffusion unit 43 to preset subfields. The data mapped for each subfield is assigned the lowest bit LSB to the subfield in which the minimum luminance weight is set, and the most significant bit MSB is assigned to the subfield in which the maximum luminance weight is set.

The frame memory 45 stores data from the subfield mapping unit 44 in units of frames.

The data sorting unit 46 for each drive IC rearranges data input from the frame memory 45 corresponding to each data drive IC and supplies the data to the data driver 49.

The data converter 48 converts the data pattern from the data alignment unit 46 for each drive IC in units of a data window of a predetermined size according to the temperature information from the temperature sensor 53. The logical value of other data in the window is replaced by the data logical value at a specific position in the data window of a predetermined size. In addition, the data converter 48 may replace all the data patterns in the data window of the predetermined size by the predetermined logical value '0' or '1', thereby replacing all the data in the window with the same value. Here, the data pattern converted by the data converter 48 in units of windows is a switching data pattern or similar data pattern that increases power consumption and heat generation of the data drive IC. On the other hand, when the temperature information from the temperature sensor 53 is less than or equal to a preset reference value, the data converter 48 bypasses the input data pattern to the data driver 53 as it is.

The temperature sensor 53 is installed adjacent to each of the data drive ICs of the data driver 49 to sense the temperature of each of the data drive ICs, and supplies the sensed temperature information to the data converter 48. The temperature sensor 53 may be implemented by any one of various types such as a thermistor, a photodiode, a photo transistor, and a thermal resistance (platinum). This temperature sensor 53 may be integrally attached to each of the drive ICs.

The data conversion process of the data conversion unit 48 is summarized in stages as shown in FIG. 5.

Referring to FIG. 5, the temperature information detected by the temperature sensor 53 is input to the data converter 48 in real time. (Step S1) The data converter 48 uses the data drive IC based on the temperature information. If it is determined that the temperature is greater than the predetermined reference value, the input data is replaced with the specific data in the window of a predetermined size and the other data in the window. (Steps S2 and S3) In step S2, the temperature of the data drive IC is set to the reference value. If determined to be within, the data converter 48 bypasses the input data to each data drive IC of the data driver 49 as it is.

As a result, when the data drive IC generates heat above a certain temperature, the data converter 48 lowers the resolution of the original data, that is, converts the original data pattern into a data pattern with a small number of switching, thereby reducing the number of switching times of the data drive IC. Will lower the temperature.

6 illustrates a data conversion process performed by the data conversion unit 48.

Referring to FIG. 6, assuming that the original data pattern 63 is a switching data pattern in which the low logic and the high logic alternate in both the column direction and the row direction, the original data pattern 63 is input to the data drive IC. The number of switching of the data drive IC is maximum, and the capacitance of the PDP, that is, the load is maximized, resulting in high power consumption and heat generation temperature of the data drive IC. When the temperature of the data drive IC is detected by the temperature sensor 53 to be higher than a specific temperature, the data conversion unit 48 is located at the uppermost left data b (1,1) at the uppermost left side of the original data pattern 63. All of the data of the 3x3 pixel window 62a including the is replaced with the data value '0' of the uppermost left data b (1,1). At the same time, the data conversion section 48 includes all of the data of the 3x3 pixel window 62b including the data b (1,4) located in the fourth row in the row direction from the leftmost side at the top of the original data pattern 63. Is replaced with the data value '1' of the uppermost left data b (1,1). Similarly, when the temperature of the data driver IC is equal to or higher than a specific temperature, the data converter 48 is placed in the raw data pattern 63 in the 3k + 1 (though k is a positive integer of 0 or more) in each of the row direction and the column direction. The value of the corresponding data b (3k + 1,3k + 1) is copied to all data in the 3x3 pixel window including it.

7 shows an apparatus for driving a PDP according to a second embodiment of the present invention.

In Fig. 7, circuit blocks having the same functions as those of the driving apparatus of the PDP shown in Fig. 4 are given the same reference numerals, and detailed description thereof will be omitted.

Referring to FIG. 7, the driving apparatus of the PDP according to the second embodiment of the present invention includes a data comparator / conversion unit 70 connected between the data alignment unit 46 and the data driver 49 for each drive IC. .

The data comparison / conversion unit 70 determines the similarity with the switching data pattern with respect to the data input from the data alignment unit 46 for each drive IC, and when the data comparison / conversion unit 70 determines that the data pattern is similar to the switching data pattern, the data resolution may be determined. It is lowered in the same way as 6. In detail, the data comparison / conversion unit 70 performs an exclusive OR operation between adjacent data in the row direction to detect the number of switching patterns in the row direction, and performs an exclusive OR operation on the adjacent one line data. XOR) to detect the number of switching patterns in the column direction. The data comparison / conversion unit 70 calculates the number of switching patterns of one screen by adding the number of switching patterns in the row direction and the number of switching patterns in the row direction, and compares the number of switching patterns of one screen with a preset reference value. . If the number of one screen switching pattern is larger than the reference value, it is determined that the data pattern has a high similarity with the switching data pattern, and the data pattern is reduced in resolution as shown in FIG. 6 by the data comparison / conversion unit 80.

In the data control method according to the present invention, the data conversion is performed in the subfields SF1, SF2, SF3 having low luminance weights as shown in FIG. 8, and other subfields SF4, which have high luminance weights. .., SFn). This is because the resolution deterioration of the subfields having the lowest brightness, that is, the smallest number of sustain discharges, is small enough to minimize the deterioration in image quality due to the resolution deterioration even though the resolution is hardly recognized or recognized by the viewer. In addition, as shown in FIG. 9, data conversion may be performed on all subfields included in one frame while accumulating the resolution conversion of the previous frame, as long as the deterioration in image quality is not apparent.

10 and 11, data conversion and data bypass are alternately performed in a subfield unit among subfields having low luminance weights or alternately in a subfield group including at least two subfields. Can be.

In addition, data conversion may be performed alternately, periodically or aperiodically on a frame basis as shown in FIG. 12.

As described above, the data control method and apparatus according to the present invention can reduce the heat generation and power consumption of the drive IC by lowering the resolution of the data pattern that the heat generation and power consumption of the drive IC can be increased.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. For example, although the embodiments of the present invention have been described based on the PDP, the same applies to the flat panel display devices such as LCD, FED, and EL, thereby reducing the heat generation and power consumption of the drive IC installed in the flat panel display. have. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

1 is a diagram illustrating a conventional frame including eight subfields in a method of driving a conventional plasma display panel.

Fig. 2 is an equivalent circuit diagram equivalently showing the capacitance of the PDP.

3 is a diagram schematically illustrating a switching data pattern.

4 is a block diagram showing a driving apparatus of a plasma display panel according to a first embodiment of the present invention.

5 is a flowchart illustrating step by step a control procedure of a data control method according to an exemplary embodiment of the present invention.

6 is a diagram illustrating a change in a data pattern during data conversion in the data control method according to an exemplary embodiment of the present invention.

7 is a block diagram showing a driving apparatus of a plasma display panel according to a first embodiment of the present invention.

FIG. 8 is a diagram illustrating a subfield section having a low luminance relative ratio in which data conversion is performed in a data control method according to an exemplary embodiment of the present invention.

9 is a diagram illustrating all subfields to which data conversion is performed in the data control method according to an exemplary embodiment of the present invention.

FIG. 10 is a diagram illustrating a subfield section in which data conversion and data bypass are alternately performed in the data control method according to an exemplary embodiment of the present invention.

FIG. 11 is a diagram illustrating a data conversion interval in which data conversion is alternately performed in units of a subfield group including at least two subfields in the data control method according to an exemplary embodiment of the present invention.

12 is a diagram illustrating that data conversion and data bypass are performed in a frame unit cycle in a data control method according to an exemplary embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

X: address electrode Y: scan electrode

Z: common sustain electrode 41: gamma correction unit

42: automatic gain control unit 43: error diffusion unit

44: subfield mapping unit 45: frame memory

46: data alignment unit 47: timing controller

48: data converter 49: data driver

50: PDP 51: scan driver

52: sustain drive unit 70: data comparison / conversion unit

Claims (21)

delete Sensing a temperature of a data driving circuit for supplying data to the plurality of data wires; And if the sensed temperature is higher than a preset temperature, copying the same data to a data area of a predetermined size adjacent to the data to lower the resolution of the data. delete The method of claim 2, Lowering the resolution of the data, And at least one or more subfields having low luminance weights. The method of claim 2, Lowering the resolution of the data, The data control method of claim 1, wherein the data is alternately performed in units of subfields in the subfields having low luminance weights. The method of claim 2, Lowering the resolution of the data, A data control method, characterized in that performed in all subfields included in one frame. The method of claim 2, Lowering the resolution of the data, A data control method, characterized in that is carried out alternately in units of a subfield group including at least two subfields. The method of claim 2, Lowering the resolution of the data, A data control method characterized in that it is carried out alternately in units of one frame period. The method of claim 2, And the resolution of the data is lowered from 1 × 1 resolution to 3 × 3 resolution. The method of claim 2, Lowering the resolution of the data, Detecting a number of inverting data values between adjacent data in the vertical direction and the horizontal direction, respectively; And comparing the inverted number of the data with a preset reference value. The method of claim 10,  And the resolution of the data is lowered if the number of inversions of the data is larger than the reference value. delete A data driving circuit for supplying data to the plurality of data wires; A temperature sensor for sensing a temperature of the data driving circuit; And a data conversion circuit for reducing the resolution of the data by copying the same data to a data area of a predetermined size adjacent to the data when the sensed temperature is higher than a preset temperature. The method of claim 13, The data conversion circuit, And when the sensed temperature is higher than a preset temperature, lowering the resolution of the data. The method of claim 13, The data conversion circuit, And converting data in subfields having a low luminance weight. The method of claim 13, The data conversion circuit, And performing data conversion in units of subfields in at least one or more subfields having low luminance weights. The method of claim 13, The data conversion circuit, A data control device, characterized by performing data conversion on all subfields included in one frame. The method of claim 13, The data conversion circuit, And converting data in units of a subfield group including at least two subfields. The method of claim 13, The data conversion circuit, A data control device characterized in that data conversion is performed alternately in units of one frame period. The method of claim 13, And the resolution is reduced by the data conversion circuit from 1 × 1 resolution to 3 × 3 resolution. The method of claim 13, The data conversion circuit, Detecting the number of inversions of data values between adjacent data in the vertical and horizontal directions, and comparing the inversion number of the data with a preset reference value, and lowering the resolution of the data when the inversion number of the data is larger than the reference value. Data control device characterized in that.