JP6620209B2 - Data driver and display device - Google Patents

Description

  The present invention relates to a data driver and a display device that drive a display panel according to image data.

  A liquid crystal display device as a display device includes a liquid crystal display panel, a plurality of data drivers that drive the liquid crystal display panel, and a control unit that transmits image data to each of the drivers. In recent years, the resolution of a liquid crystal display panel has been increased in order to display a high-definition image, and accordingly, the transmission frequency of image data in the liquid crystal display device has increased. Therefore, there is a concern about an increase in power consumption accompanying an increase in transmission frequency.

  Therefore, when the display data for one display line that are adjacent to each other are the same, the power consumption is reduced by stopping sending the voltage for driving the liquid crystal display panel to the liquid crystal display panel. A data driver has been proposed (see Patent Document 1, for example).

JP 2000-194305 A

  However, with the increase in the transmission frequency of image data in the display device, electromagnetic interference, so-called EMI (Electro-Magnetic Interference) occurs, and there is a possibility that an error occurs in the image data received on the driver side. . This causes a problem that the display quality of the image is deteriorated.

  It is an object of the present invention to provide a data driver and a display device that can suppress a decrease in display quality and an increase in power consumption.

  A data driver according to the present invention includes: a receiving unit that receives an image data signal including at least one encoded data block that has been subjected to error correction encoding processing on a series of pixel data pieces indicating the luminance level of each pixel; A decoding processing unit that performs a decoding process on the encoded data block included in the received image data signal, and a voltage corresponding to the luminance level indicated by each of the pixel data pieces obtained by the decoding process. A conversion unit that converts the pixel driving voltage into a pixel driving voltage.

  The display device according to the present invention receives and receives an image data signal including at least one encoded data block in which error correction encoding processing has been performed on a series of pixel data pieces indicating the luminance level of each pixel. The encoded data block included in the image data signal is subjected to a decoding process, and each of the pixel data pieces obtained by the decoding process is converted into a pixel driving voltage having a voltage corresponding to the luminance level indicated by the pixel data piece. A data driver, a control unit for transmitting the image data signal to the data driver, and a display panel including a plurality of data lines each receiving the pixel driving voltage.

  In the present invention, an encoded data block obtained by performing error correction coding processing on a sequence of pixel data pieces in input image data, and 3 corresponding to red, green, and blue in the series of pixel data pieces, respectively. A transmission image data signal having a representative pixel data group including one pixel data piece is transmitted to the driver of the display panel. On the driver side, a series of pixel data pieces obtained by performing error correction processing on the transmission image data signal is converted into a pixel drive voltage and applied to the display panel.

  As a result, even if an error occurs in the image data received on the driver side due to the EMI generated with the increase in the transmission frequency of the image data in the display device, the error is corrected and displayed. A high quality image can be displayed.

  When pixels for one horizontal scanning line have the same color, the above-described error correction processing is not performed and the representative pixel data group included in the transmission image data signal is converted into a pixel driving voltage. The voltage is applied to the display panel. Therefore, at this time, it is possible to reduce the power consumption by the amount that the error correction process is not performed.

  Therefore, according to the present invention, it is possible to suppress a decrease in display quality accompanying an increase in the transmission frequency of image data in the display device and to suppress an increase in power consumption.

It is a figure which shows schematic structure of the display apparatus which concerns on this invention. It is a figure which shows an example of the format of the input image data VD. 2 is a block diagram showing an internal configuration of a transmission image data signal generation unit 100. FIG. 3 is a block diagram showing an internal configuration of a line same color detection unit 101. FIG. It is a figure which shows the data format of line information LIF. It is a figure which shows the data format of the intermediate image data for transmission PA and PB, and the transmission image data signal VDT. 2 is a block diagram showing an internal configuration of a data driver 12. FIG. It is a figure which shows the data format of the pixel data block CHD sent out from the representative pixel data register 126. 4 is a flowchart showing a data reception control routine executed in the data driver 12.

  FIG. 1 is a diagram showing a schematic configuration of a display device according to the present invention.

In FIG. 1, for example, a display panel 20 as a liquid crystal panel includes a liquid crystal layer (not shown) and n (n is an integer of 2 or more) horizontal scanning lines S ₁ to S that extend in the horizontal direction of a two-dimensional screen. and S _n, m pieces which extend in the vertical direction of the two-dimensional screen (m is an integer of 2 or more) and the data lines D ₁ to D _m of are provided. A red display cell P _R responsible for red display, a green display cell P _G responsible for green display, or a blue display cell P _B responsible for blue display is formed at the intersection of the horizontal scanning line and the data line. That is, the data lines among the data lines _{D 1 ~D m (3 · t} -2) th (t is a natural number), i.e. _{D 1, D 4, D 7} , ···, each of D _m-2 red display cell P _R is formed. Further, (3 · t-1) th are arranged in the data line among the data lines D ₁ to D _m, that is _{D 2, D 5, D 8} , ···, each of D _m-1 is green display cell P _G is formed. Further, (3 · t) th are arranged in the data line among the data lines D ₁ to D _m, that is _{D 3, D 6, D 9} , ···, the D _m blue display cell P _B Is formed.

As shown in FIG. 1, on each of the horizontal scan lines S ₁ to S _n, 3 one display cells adjacent to each other, i.e. red display cell P _R, 1 single in green display cell P _G, and blue display cell P _B Pixels PX (regions surrounded by broken lines) are formed.

  The drive control unit 10 generates a scanning control signal synchronized with the input image data VD, and supplies this to the scanning driver 11.

For example, as shown in FIG. 2, the input image data VD is composed of a series of pixel data QD _{1 to} QD _m representing the luminance level of each pixel in the display panel 20 with, for example, 8 bits for each horizontal scanning line. The arrangement in a series of pixel data QD ₁ ~QD _m, the pixel data _{QD 1, QD 4, QD 7} , ···, QD m-5, QD m-2, that is, (3 · t-2) -th The pixel data QD displayed represents the luminance level of the red component. Further, in the series of pixel data QD _{1 to} QD _m , the pixel data QD ₂ , QD ₅ , QD ₈ ,..., QD _m-4 , QD _m−1 , that is, (3 · t−1) th are arranged. The pixel data QD displayed represents the luminance level of the green component. Also, in the series of pixel data QD _{1 to} QD _m , pixel data QD ₃ , QD ₆ , QD ₉ ,..., QD _m-3 , QD _m , that is, (3 · t) th pixel arranged Data QD represents the luminance level of the blue component.

  The drive control unit 10 generates a transmission image data signal VDT based on the input image data VD and transmits it to the data driver 12. The generation operation of the transmission image data signal VDT by the drive control unit 10 will be described later.

The scan driver 11 generates a scan pulse in response to the scan control signal supplied from the drive control unit 10 sequentially alternatively applies it to the horizontal scanning lines S ₁ to S _n of the display panel 20.

  The data driver 12 is formed by being distributed over a single semiconductor chip or a plurality of semiconductor chips.

First, the data driver 12 restores the series of pixel data QD shown in FIG. 2 by performing a decoding process on the received transmission image data signal VDT. Details of the decoding process by the data driver 12 will be described later. The data driver 12 sequentially captures and holds the restored series of pixel data QD. At this time, each time the capturing of m pixel data QD for one horizontal scanning line is completed, the data driver 12 sets each of the m pixel data QD to the luminance level indicated by the pixel data QD. These are converted into corresponding analog voltages, and these are applied to the data lines D _{1 to} D _m of the display panel 20 as pixel drive voltages G _{1 to} G _m .

  Hereinafter, the generation and transmission operation of the transmission image data signal VDT by the drive control unit 10 and the operation of the data driver 12 will be described.

  FIG. 3 is a block diagram illustrating an example of an internal configuration of the transmission image data signal generation unit 100 that is provided in the drive control unit 10 and generates and transmits the transmission image data signal VDT. As illustrated in FIG. 3, the transmission image data signal generation unit 100 includes a line identical color detection unit 101, an error correction coding unit 102, an interleave processing unit 103, and a transmission unit 104.

  The line same color detection unit 101 has an internal configuration shown in FIG. 4, for example. In FIG. 4, when the mode signal MOD indicates the high image quality mode, the color correction unit 101x supplies the input image data VD as it is to the color separation / extraction unit 101a as image data VDX. On the other hand, when the mode signal MOD indicates the low power consumption mode, the input image data VD subjected to the following correction is supplied as the image data VDX to the color separation / extraction unit 101a.

  That is, in the low power consumption mode, the color correction unit 101x first obtains the frequency of the color expressed by each pixel for each horizontal scanning line based on the input image data VD. Next, the color correcting unit 101x sets the color having the highest frequency, that is, the largest color among the colors expressed by each pixel for one horizontal scanning line, as the reference color. When there are a plurality of colors having the highest frequency, the color correction unit 101x sets the average color of each pixel for one horizontal scanning line as the reference color based on the input image data VD.

  Next, the color correction unit 101x obtains a difference between the color represented by the pixel and the reference color for each pixel for the one horizontal scanning line described above. That is, the color correction unit 101x includes the luminance of each of the red, green, and blue components in the reference color (hereinafter referred to as reference red luminance, reference green luminance, and reference blue luminance), red in each pixel based on the input image data VD, The difference between the brightness of each of the green and blue components is obtained for each color component (red, green, blue). Hereinafter, a difference with respect to the reference red luminance is referred to as a red difference, a difference with respect to the reference green luminance is referred to as a green difference, and a difference with respect to the reference blue luminance is referred to as a blue difference.

  Next, the color correction unit 101x determines whether or not all the color differences including the red difference, the green difference, and the blue difference are within a predetermined range, for example, a range of 5% to −5% of the maximum luminance. Judge every time. Note that the color correction unit 101x may determine, for each pixel, whether the total of the red difference, the green difference, and the blue difference is within a range of 10% to −10% of the maximum luminance, for example. .

  Here, when it is determined that the difference between the color components is within the predetermined range, the color correction unit 101x determines the luminance level indicated by the pixel data QD of each color component corresponding to the pixel as the reference color. Correction for replacing the luminance level value of each color component is performed. On the other hand, when it is determined that the difference between the color components is not within the predetermined range, the color correction unit 101x performs the above correction on each of the pixel data QD of each color component corresponding to the pixel. Not performed.

  Then, the color correction unit 101x supplies the pixel data QD in the input image data VD subjected to the above processing to the color separation / extraction unit 101a as image data VDX.

The color separation and extraction unit 101a sequentially extracts the pixel data QD from in the sequence of pixel data QD represented by the image data VDX representing the luminance level of the red component as a red pixel data QD _R. That is, the color separation / extraction unit 101a performs pixel data QD ₁ , QD ₄ , QD ₇ ,..., QD arranged in the (3 · t−2) th in the series of pixel data QD shown in FIG. sequentially extracting each of _m-5, QD _m-2 as a red pixel data QD _R. The color separation / extraction unit 101a supplies the red pixel data QD _R series to the red identity determination unit 101b and the LIF generation unit 101c.

The color separation and extraction unit 101a sequentially extracts the pixel data QD indicating the luminance level of the green component from the in-series pixel data QD represented by the image data VDX as a green pixel data QD _G. That is, the color separation / extraction unit 101a performs pixel data QD ₂ , QD ₅ , QD ₈ ,..., QD arranged in the (3 · t−1) th in the series of pixel data QD shown in FIG. Each of _m−4 and QD _m−1 is sequentially extracted as green pixel data QD _G. The color separation and extraction unit 101a supplies a series of such green pixel data QD _G green same determination unit 101d and LIF generator 101c.

Further, the color separation and extraction unit 101a sequentially extracts the pixel data QD from in the sequence of pixel data QD represented by the image data VDX representing the luminance level of the blue component as a blue pixel data QD _B. That is, the color separation / extraction unit 101a performs pixel data QD ₃ , QD ₆ , QD ₉ ,..., QD _m− arranged in the (3 · t) -th among the series of pixel data QD shown in FIG. ₃ sequentially extracts each QD _m as a blue pixel data QD _B. The color separation and extraction unit 101a supplies a series of such blue pixel data QD _B blue same determination unit 101e and the LIF generator 101c.

Red identity determination unit 101b, first red pixel data QD _R of the horizontal scan line, i.e. pixel data _{QD 1, QD 4, QD 7} , ···, QD m-5, and QD _m-2 the same luminance level It is determined whether or not. Red identity determination unit 101b, it is determined that all the QD _R of logic level 1, 1 horizontal scanning line in the case where the red pixel data QD _R of one horizontal scanning line is determined to be the same is not the same supplying red coincidence determination signal L _R of the logic level 0 to the aND gate 101f when the.

The green identity determination unit 101d has green pixel data QD _{G for} one horizontal scanning line, that is, pixel data QD ₂ , QD ₅ , QD ₈ ,..., QD _m-4 , QD _m-1 have the same luminance level. It is determined whether or not there is. Green identity determination unit 101d, it is determined that all the QD _G logic level 1, 1 horizontal scanning lines in the case of green pixel data QD _G of one horizontal scanning line is determined to be the same is not the same supplying green match determination signal L _G of logic level 0 to the aND gate 101f when the.

The blue identity determination unit 101e determines whether the blue pixel data QD _{B for} one horizontal scanning line, that is, the pixel data QD ₃ , QD ₆ , QD ₉ ,..., QD _m-3 , QD _m have the same luminance level. Determine whether or not. Blue identity determination unit 101e, it is determined that all of the logic level 1, 1 horizontal scanning line of the QD _B when one horizontal scan line of blue pixel data QD _B is determined to be identical not identical supplying blue match determination signal L _B of the logic level 0 to the aND gate 101f when the.

AND gate 101f is a logic level 1 when the red coincidence determination signal L _R, green match determination signal L _G and the blue coincidence determination signal L _B are all the logic level 1, in other cases has a logic level 0 The line same color data LC is supplied to the LIF generator 101c.

  In other words, the AND gate 101f has a logic level of 1 when all the pixels PX for one horizontal scanning line have the same color (hereinafter referred to as one line and the same color) in the high image quality mode described above. When the same color is not obtained, the line same color data LC of logic level 0 is supplied to the LIF generation unit 101c. On the other hand, in the low power consumption mode, the AND gate 101f is represented by the most frequent reference color among the colors represented by the pixels PX for one horizontal scanning line and the pixels PX for the one horizontal scanning line. When all the color differences from the respective colors are within the predetermined range, the line same color data LC of the logic level 1 is supplied to the LIF generation unit 101c.

LIF generating unit 101c shows the above-mentioned line the same color data LC, based on the red pixel data QD _R, green pixel data QD _G and the blue pixel data QD _B, generates the line information LIF including data format shown in FIG. 5, which Is held in a built-in register (not shown).

That is, the LIF generation unit 101c first holds the line same color data LC supplied from the AND gate 101f in the built-in register. Next, the LIF generation unit 101c holds one of the red pixel data QD _R supplied from the color separation / extraction unit 101a as representative red pixel data H _R in the built-in register. The LIF generation unit 101c holds one of the green pixel data QD _G supplied from the color separation / extraction unit 101a as representative green pixel data H _G in the built-in register. Furthermore, LIF generating unit 101c, one of the blue pixel data QD _B each supplied from the color separation and extraction unit 101a as representative blue pixel data H _B, held in the internal register.

Further, the LIF generation unit 101c applies, for example, CRC (for CRC) to the data block composed of the same line color data LC, representative red pixel data H _R , representative green pixel data H _G, and representative blue pixel data H _B held in the built-in register. An error detection encoding process is performed according to (Cyclic Redundancy Check). The LIF generation unit 101c holds the error check data CRC obtained by the error detection encoding process in a built-in register.

The LIF generation unit 101c stores line information including the line same color data LC, the representative red pixel data H _R , the representative green pixel data H _{G, the} representative blue pixel data H _B , and the error check data CRC held in the built-in register. The LIF is supplied to the LIF adding unit 101g.

As shown in FIG. 6, the LIF adding unit 101g adds line information LIF to the head of each pixel data block HQD composed of pixel data QD _{1 to} QD _m for one horizontal scanning line in the input image data VD. Those are generated as intermediate image data PA for transmission.

  Therefore, with the configuration shown in FIG. 4 described above, the line identical color detection unit 101 generates the transmission intermediate image data PA shown in FIG. 6 based on the input image data VD, and supplies this to the error correction encoding unit 102. .

  The error correction encoding unit 102 generates an encoded data block CDD in which error correction code data ERR is added to the HQD by performing error correction encoding processing on the pixel data block HQD in the transmission intermediate image data PA. To do. As shown in FIG. 6, the error correction encoding unit 102 supplies the intermediate image data PB for transmission obtained by adding the line information LIF to the head of the encoded data block CDD to the interleaving unit 103.

  The interleaving unit 103 obtains an encoded data block ILV by performing an interleaving process for changing the data arrangement on the encoded data block CDD of the transmission intermediate image data PB shown in FIG.

  As illustrated in FIG. 6, the transmission unit 104 transmits a transmission image data signal VDT including a data series including the line information LIF and the encoded data block ILV to the data driver 12 via the transmission line LL.

  FIG. 7 is a block diagram illustrating an example of the internal configuration of the data driver 12. In FIG. 7, the interface unit 121 captures the transmission image data signal VDT received via the transmission line LL at a timing according to the clock signal, and supplies this to the LIF capturing unit 122 and the data decoding unit 123.

The LIF capturing unit 122 captures line information LIF from the transmission image data signal VDT shown in FIG. The LIF acquisition unit 122 supplies the line information LIF shown in FIG. 5 to the error detection unit 124 and supplies the line same color data LC in the line information LIF to the AND gate 125. Further, the LIF fetch unit 122 supplies the representative red pixel data H _R , the representative green pixel data H _G and the representative blue pixel data H _B in the line information LIF shown in FIG.

Based on the error check data CRC included in the line information LIF, the error detection unit 124 uses the same line color data LC, representative red pixel data H _R , representative green pixel data H _G and representative blue pixel data H included in the line information LIF. _It is detected whether or not there is an error bit in the sequence consisting of _B. At this time, the error detection unit 124 supplies the AND gate 125 with the error detection signal ER at the logic level 0 when there is an error bit and when there is no error bit.

  The AND gate 125 is a logic level 1 line when the error detection signal ER and the line same color data LC are both at the logic level 1, and a logic level 0 line when at least one of the ER and LC is at the logic level 0. The same pixel signal SE is generated. That is, the AND gate 125 generates the line identical pixel signal SE of the logic level 1 when there is no error in the line information LIF and the line identical color data LC included in the line information LIF indicates one line identical color. On the other hand, if an error has occurred in the line information LIF or the line same color data LC indicates that one line is not the same color, the AND gate 125 generates a line same pixel signal SE of logic level 0. .

  The AND gate 125 supplies the line same pixel signal SE to the data decoding unit 123, the representative pixel register 126, and the selector 127.

  The data decoding unit 123 is in a state of performing the following decoding process when the logical level 0 line identical pixel signal SE is supplied, while the logical level 1 line identical pixel signal SE is supplied. Has a deinterleave circuit DV and an error correction circuit EE set to the operation stop state.

  The deinterleave circuit DV performs a deinterleave process for returning the data arrangement to the encoded data block ILV in the transmission image data signal VDT shown in FIG. Accordingly, the deinterleave circuit DV restores the encoded data block CDD composed of the pixel data block HQD and the error correction code data ERR. For example, the deinterleave circuit DV first writes the encoded data block ILV once in a first processing area of a RAM (Random Access Memory) 128. Here, the deinterleave circuit DV divides and reads the encoded data block ILV from the first processing area, and the data arrangement thereof is the same as the pixel data block HQD and the error correction code data ERR shown in FIG. The rearranged data is written in the second processing area of the RAM 128. Therefore, the encoded data block CDD composed of the pixel data block HQD and the error correction code data ERR restored by the deinterleaving process is held in the second processing area of the RAM 128. The deinterleave circuit DV supplies the pixel data block HQD and the error correction code data ERR held in the second processing area of the RAM 128 to the error correction circuit EE. The RAM 128 has an area for holding intermediate data generated by the following error detection and error correction process in addition to the first and second processing areas used in the deinterleaving process.

The error correction circuit EE performs error detection and error correction processing on the encoded data block CDD restored by the deinterleave circuit DV. At this time, intermediate data generated in the process of error detection and error correction is written into the RAM 128 and read out as necessary. The error correction circuit EE corrects an error occurring in the encoded data block CDD by error detection and error correction processing, whereby a series of pixel data QD _{1 to} QD _m for one horizontal scanning line shown in FIG. And a pixel data block HQD composed of the restored pixel data QD _{1 to} QD _m is obtained.

  As described above, the data decoding unit 123 supplies the selector 127 with the pixel data block HQD obtained by performing decoding processing, that is, deinterleaving processing and error correction processing, on the received transmission image data signal VDT.

The representative pixel register 126 holds single representative red pixel data H _R , representative green pixel data H _G, and representative blue pixel data H _B supplied from the LIF capturing unit 122, respectively. The representative pixel register 126 performs the following read operation when the line level pixel signal SE of logic level 1 is supplied.

That is, the representative pixel register 126, the representative red pixel data H _R that is stored, the representative green pixel data H _G and representative blue pixel data H _B, one horizontal scanning line as shown in FIG. 8, H _R, Reading is repeated periodically in the order of H _G and H _B. The representative pixel register 126 supplies the pixel data block CHD composed of m H _R , H _G , and H _{B for} one horizontal scanning line read out to the selector 127.

  The representative pixel register 126 is in an operation stop state when the line same pixel signal SE of logic level 0 is supplied.

  The selector 127 selectively selects one of the pixel data block CHD supplied from the representative pixel register 126 and the pixel data block HQD supplied from the data decoding unit 123, which is indicated by the line same pixel signal SE. To do. That is, the selector 127 selects the pixel data block HQD when the line same pixel signal SE indicates the logic level 0, and selects the pixel data block CHD when the line same pixel signal SE indicates the logic level 1. . The selector 127 supplies the data latch 129 which is selected as described above from the pixel data blocks HQD and CHD.

That is, the selector 127 supplies the pixel data block HQD decoded by the data decoding unit 123 to the data latch 129 according to the line same pixel signal SE of logical level 0 indicating that one line is not the same color. Further, in response to a line-same pixel signal SE of logical level 1 indicating one line and the same color, the selector 127 sends a pixel data block CHD composed of representative pixel data groups (H _R , H _G , H _B ) to the data latch 129. Supply.

The data latch 129 sequentially fetches m pixel data pieces (QD, H) for one horizontal scanning line included in the pixel data block HQD or CHD, and converts them into pixel data SD _{1 to} SD _m as gradation voltages. This is supplied to the generation unit 130.

The gradation voltage generation unit 130 converts the pixel data SD _{1 to} SD _m into analog gradation voltages corresponding to the luminance levels indicated by each. The gradation voltage generator 130 applies gradation voltages corresponding to the pixel data SD _{1 to} SD _m to the data lines D _{1 to} D _m of the display panel 20 as pixel driving voltages G _{1 to} G _m , respectively.

With the above configuration, the data driver 12 obtains one of the pixel data blocks HQD and CHD based on the received transmission image data signal VDT shown in FIG. That is, an error has occurred in the line information LIF included in the transmission image data signal VDT (ER = 0), or the line same color data LC included in the line information LIF does not indicate one line same color (LC = 0). ), The data driver 12 generates a pixel data block HQD. That is, in this case, the data decoding unit 123 performs deinterleaving processing and error correction processing on the encoded data block ILV of the transmission image data signal VDT, so that the pixel data QD ₁ to QD _m shown in FIG. This pixel data block HQD is restored. Then, the selector 127 supplies the pixel data block HQD to the data latch 129 so that the pixel data QD _{1 to} QD _m for one horizontal scanning line included in the HQD is taken into the data latch 129. As a result, the gradation voltage generation unit 130 generates analog pixel drive voltages G _{1 to} G _m corresponding to the pixel data QD _{1 to} QD _m shown in FIG. 6 and generates data lines D ₁ to D of the display panel 20. Apply to _Dm .

On the other hand, if no error has occurred in the line information LIF (ER = 1) and the line same color data LC indicates one line same color (LC = 1), the data driver 12 receives the transmitted image data. A pixel data block CHD is generated based on the signal VDT. That is, in this case, the representative pixel register 126 converts each single representative red pixel data H _R , representative green pixel data H _G, and representative blue pixel data H _B included in the line information LIF to H H as shown in FIG. Read out periodically in the order of _R , H _G , H _B. Thus, representative pixel register 126, three representative red pixel data H _R, representative green pixel data H _G and representative blue pixel data H to generate repeatedly arranged pixel data blocks CHD over one horizontal scanning line. The selector 127 supplies the pixel data block CHD to the data latch 129, whereby the representative red pixel data H _R , the representative green pixel data H _G, and the representative blue pixel data H for one horizontal scanning line included in the CHD. _B is taken into the data latch 129. As a result, the gradation voltage generation unit 130 is an analog pixel driving voltage in which one horizontal scanning line has the same color based on the three representative red pixel data H _R , the representative green pixel data H _G, and the representative blue pixel data H _B. G _{1 to} G _m are generated and applied to the data lines D _{1 to} D _m of the display panel 20.

  As described above, in the display device shown in FIG. 1, the drive control unit 10 transmits the transmission image data signal VDT obtained by performing error correction coding processing and interleaving processing on the input image data VD to the transmission line LL. To the data driver 12. At this time, the data driver 12 performs deinterleaving processing and error correction processing on the received transmission image data signal VDT. As a result, the data driver 12 restores the series of pixel data QD indicated by the input image data VD from the received transmission image data signal VDT, and the series of the pixel data QD is equivalent to one horizontal scanning line (m). The data is latched by the data latch 129.

  Therefore, according to such a configuration, even if an error occurs in the transmission image data signal VDT received by the data driver 12 due to the influence of EMI generated with the increase in the transmission frequency of the image data signal, this is corrected. Correction can be made on the data driver 12 side. Accordingly, it is possible to prevent a reduction in display quality even in an EMI environment accompanying an increase in the frequency of the image data signal.

Further, in the drive control unit 10, when pixel data QD _{1 to} QD _m for displaying each pixel PX on one horizontal scanning line in the same color exists in the input image data VD, first, the QD Three pixel data for forming the color are selected as representative pixel data (H _R , H _G , H _B ) from _{1 to} QD _m . Then, the drive control unit 10 outputs line information LIF including line same color data LC indicating whether or not each pixel on one horizontal scanning line is in the same color state together with these H _R , H _G and H _B. As shown in FIG. 6, the data included in the transmission image data signal VDT is transmitted to the data driver 12.

Here, in the data driver 12, when the line same color data LC indicates that each pixel on one horizontal scanning line has the same color, deinterleaving processing and error correction processing for the received transmission image data signal VDT are performed. The following processing is performed without performing the above. That is, the three representative red pixel data H _R , the representative green pixel data H _G and the representative blue pixel data H _B included in the line information LIF are repeated for one horizontal scanning line (m), and the data latch 129 It is taken in.

  Therefore, according to such a configuration, when all pixels on one horizontal scanning line have the same color, the above deinterleaving process and error correction process are not performed on the received transmission image data signal VDT, and Access to the RAM 128 associated with the process is not performed. Therefore, the power consumption and the heat generation amount can be reduced by the amount that the deinterleaving process, the error correction process, and the access to the RAM 128 are not performed.

  As described above, the display device shown in FIG. 1 consumes power without degrading the display quality even when the transmission frequency of the image data signal in the display device is increased as the display panel becomes higher in definition. It is possible to suppress an increase in the amount and the calorific value.

  In the configuration of the data driver 12 shown in FIG. 7, the data reception operation from the reception of the transmission image data signal VDT to the transmission of the pixel data group for one horizontal scanning line to the data latch 129 is performed by hardware (121-121). 127), this may be implemented by software.

  FIG. 9 is a flowchart showing a data reception control routine executed by a control unit (not shown) in the data driver 12 made in view of this point.

In FIG. 9, first, the control unit of the data driver 12 takes in the line information LIF shown in FIG. 5 from the received transmission image data signal VDT (step S1). Next, as shown in FIG. 5, the control unit performs error detection processing on the line information LIF based on the error check data CRC included in the line information LIF (step S2), and whether or not there is an error. Is determined (step S3). When it is determined in step S3 that there is no error, the control unit determines that the line same color data LC included in the line information LIF indicates that each pixel on one horizontal scanning line is in the same color state. It is determined whether or not 1 (step S4). If it is determined in step S4 that the line same color data LC is at the logic level 1, the control unit, as shown in FIG. 5, represents the representative red pixel data H _R and the representative green pixel data included in the line information LIF. H _G and representative blue pixel data H _B are repeated for one horizontal scanning line (m) and sent to the data latch 129 (step S5).

On the other hand, if it is determined that there is an error in the line information LIF in step S3, or the line same color data LC is at the logic level 0 indicating that all the pixels on one horizontal scanning line are not in the same color state. When it determines with, a control part performs the following step S6. That is, the control unit performs deinterleaving processing on the encoded data block ILV shown in FIG. 6 in the received transmission image data signal VDT, so that the pixel data QD _{1 to} QD _m and error correction shown in FIG. The encoded data block CDD composed of the encoded data ERR is restored (step S6). Next, the control unit performs error correction processing on the encoded data block CDD to obtain error-corrected pixel data QD _{1 to} QD _m and send them to the data latch 129 (step S7). .

  The control unit of the data driver 12 performs the above-described control of steps S1 to S5 or S1 to S4, S6, and S7 for each horizontal scanning line with respect to the received transmission image data signal VDT.

  In short, in the display device shown in FIG. 1, first, the control unit (10) generates a transmission image data signal (VDT) based on the input image data (VD) and transmits it to the driver (12) as follows. To do.

The control unit (10) includes a line identical color detection unit (101x, 101a to 101f), a representative pixel extraction unit (101a, 101c), an error correction coding unit (102), and a transmission unit (104). The line same color detection unit generates line same color data (LC) for each horizontal scanning line indicating whether or not pixels for one horizontal scanning line have the same color based on a series of pixel data pieces in the input image data. To do. The representative pixel extraction unit extracts three pixel data pieces (H _R , H _G , H _B ) corresponding to red, green, and blue from the series of pixel data pieces as a representative pixel data group. The error correction encoding unit generates an encoded data block (CDD) by performing error correction encoding processing on a series of pixel data pieces. The transmission unit generates a transmission image data signal including the line same color data, the representative pixel data group, and the encoded data block, and transmits the transmission image data signal to the driver.

When the driver (12) indicates that the line same color data in the received transmission image data signal is not the same color, the driver (12) performs error correction processing (EE) on the encoded data block in the transmission image data signal. subjecting applied to a plurality of data lines (D ₁ to D _m) of each of the resulting pixel data pieces converted into pixel drive voltage (130) to the display panel (20). On the other hand, when the line same color data indicates the same color, the driver (12) converts each pixel data piece included in the representative pixel data group in the transmission image data signal into a pixel drive voltage. It is applied to a plurality of data lines of the display panel.

  In the high image quality mode, the line identical color detection unit determines that the pixels for one horizontal scanning line have the same color when all the pixels for one horizontal scanning line have the same color. On the other hand, in the low power consumption mode, the same line color detection unit is represented by the most frequent reference color among the colors represented by pixels for one horizontal scanning line and each pixel for one horizontal scanning line. When all the color differences from each color are within a predetermined range, it is determined that the pixels for one horizontal scanning line are the same color.

DESCRIPTION OF SYMBOLS 10 Drive control part 12 Data driver 20 Display panel 101 Line same color detection part 102 Error correction encoding part 123 Data decoding part 126 Representative pixel register 127 Selector 128 Data latch DV Deinterleave circuit EE Error correction circuit

Claims (7)

A receiving unit that receives an image data signal including at least one encoded data block that has been subjected to error correction encoding processing on a series of pixel data pieces indicating the luminance level of each pixel;
A decoding processing unit that performs a decoding process on the encoded data block included in the received image data signal;
Have a, a conversion unit for converting each of the pixel data pieces obtained by said decoding processing, the pixel drive voltage having a voltage corresponding to the luminance level indicated respectively
The image data signal includes a plurality of the encoded data blocks,
Line same color data indicating whether or not each pixel corresponding to all the pixel data pieces in one encoded data block of the plurality of encoded data blocks represents the same color, and the one encoded A representative pixel data group consisting of three pixel data pieces respectively corresponding to red, green and blue selected from the series of pixel data pieces in a data block;
The conversion unit converts each of the pixel data pieces included in the representative pixel data group in the image data signal into the pixel driving voltage when the line same color data represents the same color. A featured data driver. Each of the pixel data pieces obtained by the decoding process performed on the encoded data block in the image data signal when the line same color data does not represent the same color. The data driver according to claim 1 , wherein the data driver is converted into the pixel drive voltage. The encoded data block is subjected to an interleaving process,
The decryption processing unit
A deinterleaving circuit that performs a deinterleaving process on the encoded data block included in the received image data signal;
The data driver according to claim 1 or 2, characterized in that it comprises, an error correction circuit which performs error correction on the encoded data blocks restored by the deinterleaving process. When the line same color data indicates the same color,
The decoding processing unit does not perform the deinterleave processing and the error correction processing, and the conversion unit converts each of the pixel data pieces included in the representative pixel data group in the image data signal into the pixel driving voltage. The data driver according to claim 3 , wherein: A data driver according to any one of claims 1 to 4 ,
A control unit for transmitting the image data signal to the data driver;
And a display panel including a plurality of data lines each receiving the pixel driving voltage. 6. The control unit according to claim 5 , further comprising an error correction encoding unit that generates the encoded data block by performing an error correction encoding process on the series of pixel data pieces. Display device. The display panel includes a plurality of horizontal scanning lines arranged to cross the plurality of data lines,
The controller is
A line same color detection unit that generates line same color data indicating whether or not the pixels for one horizontal scanning line have the same color based on the series of pixel data pieces, and a red color from the series of pixel data pieces A representative pixel extraction unit that extracts three pixel data pieces respectively corresponding to green and blue as a representative pixel data group,
Wherein for each horizontal scan line, said line the same color data, the representative pixel data groups, and claim 5 or and transmits a signal including the coded data blocks in the data driver as the image data signal 6. The display device according to 6 .

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