`
`111111 111111
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`1111111111111111111111111111111111111111111111111111111111111111111111111111 1111111111111111111111111111111111111111111111111111111111111111111111111111
`
`us 20040196229Al us 20040196229Al
`
`
`(19) United States (19) United States
`
`(12) Patent Application Publication (12) Patent Application Publication
`
`Ham Ham
`
`
`(10) Pub. No.: US 2004/0196229 Al (10) Pub. No.: US 2004/0196229 Al
`
`Oct. 7, 2004 Oct. 7, 2004
`
`(43) Pub. Date: (43) Pub. Date:
`
`
`(54) METHOD AND APPARATUS FOR DRIVING (54) METHOD AND APPARATUS FOR DRIVING
`
`LIQUID CRYSTAL DISPLAY LIQUID CRYSTAL DISPLAY
`
`(75)
`(75)
`
`
`
`Inventor: Yong Sung Ham, Kyounggi-do (KR) Inventor: Yong Sung Ham, Kyounggi-do (KR)
`
`
`Correspondence Address: Correspondence Address:
`
`MORGAN LEWIS & BOCKIUS LLP MORGAN LEWIS & BOCKIUS LLP
`
`1111 PENNSYLVANIA AVENUE NW 1111 PENNSYLVANIA AVENUE NW
`
`WASHINGTON, DC 20004 (US) WASHINGTON, DC 20004 (US)
`
`
`
`(73) (73)
`
`
`
`Assignee: LG. Philips LCD Co., Ltd. Assignee: LG. Philips LCD Co., Ltd.
`
`
`
`(21) (21)
`
`
`
`Appl. No.: Appl. No.:
`
`
`
`10/826,310 10/826,310
`
`
`
`(22) (22)
`
`Filed:
`Filed:
`
`Apr. 19, 2004
`Apr. 19, 2004
`
`
`
`Related U.S. Application Data Related U.S. Application Data
`
`
`
`(63) (63)
`
`
`Continuation of application No. 09/994,041, filed on Continuation of application No. 09/994,041, filed on
`Nov. 27, 2001. Nov. 27, 2001.
`
`
`
`
`(30) (30)
`
`
`
`Foreign Application Priority Data Foreign Application Priority Data
`
`
`
`Sep. 4, 2001 Sep. 4, 2001
`
`
`
`(KR) .................................... P2001-54127 (KR) .................................... P2001-54127
`
`Publication Classification
`Publication Classification
`
`(51)
`(51)
`
`Int. CI? ....................................................... G09G 3/36 Int. CI? ....................................................... G09G 3/36
`
`(52) U.S. CI. ................................................................ 345/87 (52) U.S. CI. ................................................................ 345/87
`
`(57)
`(57)
`
`
`
`ABSTRACT ABSTRACT
`
`
`The present invention discloses a method and apparatus for The present invention discloses a method and apparatus for
`
`driving a liquid crystal display device suitable for enhancing driving a liquid crystal display device suitable for enhancing
`
`a picture quality. More specifically, in the method and a picture quality. More specifically, in the method and
`
`apparatus, source data is modulated based on registered data apparatus, source data is modulated based on registered data
`
`that is previously provided therein. The modulated data is that is previously provided therein. The modulated data is
`
`applied to a liquid crystal panel at the initial period of one applied to a liquid crystal panel at the initial period of one
`
`frame period. A data different from the modulated data is frame period. A data different from the modulated data is
`
`supplied to the liquid crystal panel at the later period of the supplied to the liquid crystal panel at the later period of the
`
`frame period. frame period.
`
`
`
`51 51
`
`
`
`/ /
`
`
`Data .--- TIMING Data .--- TIMING
`
`------
`
`
`CONTR-CONTR-
`
`OLLER OLLER
`
`
`
`HV HV
`
`
`
`59 59
`
`
`
`'1 '1
`
`
`
`MEMORY MEMORY
`
`~ LINE ~ LINE
`
`
`52 52
`
`I AMdata I AMdata
`
`J J
`
`DATA DATA
`
`"' MODULATOR I "' MODULATOR I
`
`
`
`RGB RGB
`
`
`I I
`
`t Delk t Delk
`
`
`
`GSP GSP
`
`
`GATE GATE
`
`DRIVER DRIVER
`
`
`I I
`
`54 54
`
`
`
`~SW ..... 58 ~SW ..... 58
`
`
`
`SWITCH -SWITCH -
`
`
`
`DATA DRIVER DATA DRIVER
`
`
`
`rr ... rr ...
`
`
`Cle Cle
`
`Vearn Vearn
`
`
`53 53
`
`L L
`
`
`
`-55 -55
`
`
`
`-- 57 -- 57
`
`
`56 56
`
`.../ .../
`
`
`
`/ /
`
`SHARP EXHIBIT 1005
`
`Page 1 of 11
`
`

`

`
`
`Patent Application Publication Oct. 7,2004 Sheet 1 of 5 Patent Application Publication Oct. 7,2004 Sheet 1 of 5
`
`
`
`US 2004/0196229 Al US 2004/0196229 Al
`
`FIG .1 FIG .1
`
`
`CONVE'NTIONAL ART CONVE'NTIONAL ART
`
`
`
`1 FRAME 1 FRAME
`
`
`
`
`
`I I
`
`~ I ~ I
`
`
`
`I VD I VD
`
`BRIGHT(cid:173)
`BRIGHT(cid:173)
`NESS
`NESS
`
`
`
`v v
`
`BL
`BL
`
`
`
`v v
`
`TIME
`TIME
`
`FIG.2 FIG.2
`
`
`CONVENTIONAL ART CONVENTIONAL ART
`
`VD
`VD
`M B L --h:~"""'"
`MBL--b.:~~
`B L
`B L
`1-~_-4'_~ __ "'~
`1-~_-4'_=r __ ... ~
`
`
`I I
`I I
`I
`I
`I
`I
`
`I I
`
`I I
`I
`I
`I
`I
`
`BRIGHT(cid:173)
`BRIGHT(cid:173)
`
`NESS NESS
`
`r----
`r----
`
`TIME
`TIME
`
`Page 2 of 11
`
`

`

`Patent Application Publication Oct. 7,2004 Sheet 2 of 5
`Patent Application Publication Oct. 7,2004 Sheet 2 of 5
`
`
`
`US 2004/0196229 Al US 2004/0196229 Al
`
`FIG.3 FIG.3
`
`CONVENTIONAL ART
`CONVENTIONAL ART
`
`Fn-1 1 0 1 0 11 11 1 0 11 1 0 11 I
`Fn-1 1 0 1 0 11 11 1 0 11 1 0 11 I
`
`'----v----J '----v----J
`
`4 MOST SIGNIFICANT BITS 4 MOST SIGNIFICANT BITS
`
`Fn I 0 11 1 0 1 0 11 11 11 11 I
`Fn I 0 11 1 0 1 0 11 11 11 11 I
`
`'----v----J '----v----J
`
`4 MOST SIGNIFICANT BITS 4 MOST SIGNIFICANT BITS
`
`
`
`Mdata I 0 11 11 1 0 11 11 11 11 I Mdata I 0 11 11 1 0 11 11 11 11 I
`
`'----v----J
`'----v----J
`4 MOST SIGNIFICANT BITS
`4 MOST SIGNIFICANT BITS
`
`FIG.4 FIG.4
`
`CONVENTIONAL ART
`CONVENTIONAL ART
`
`41
`41
`(
`LSB
`RGB
`(
`LSB
`RGB
`Data--M-S:-B-.-J-----F----------.~RGB
`Data--M-S-B-..I.-----F----------+-~RGB
`
`n n
`
`In In
`
`MData MData
`
`Out Out
`
`·1
`,~
`
`4 4
`
`~
`
`FRAME
`FRAME
`
`'-- MEMORY L-- MEMORY
`~43
`\..43
`
`
`
`Fn-1 Fn-1
`
`-
`
`~
`
`LOOK-UP
`LOOK-UP
`TABLE
`TABLE
`
`44
`44
`
`Page 3 of 11
`
`

`

`Patent Application Publication Oct. 7, 2004 Sheet 3 of 5
`Patent Application Publication Oct. 7, 2004 Sheet 3 of 5
`
`US 2004/0196229 Al
`US 2004/0196229 Al
`
`(1) ~ r
`
`L.()
`L.()
`, . - - L.()
`
`I
`
`(1)
`L.(),
`L.()"
`
`
`a: a:
`W >
`W >
`
`a: a:
`.. 0
`... 0
`«
`«
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`Ii?
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`
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`~ ~
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`I
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`
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`CJ)
`CJ)
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`\
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`
`
`a: Ww a: Ww
`1-> «-
`1-> «-
`(9~
`(9~
`
`'--,.--
`L..-.--
`
`.::s:. .::s:.
`° a...
`° a...
`oCf.)
`oCf.)
`(9 ..
`(9 .
`
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`
`-
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`
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`ctS
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`....... .......
`ctS
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`a:
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`00 00
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`~r
`
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`
`z~
`z~
`
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`
`~ ~
`
`T
`
`
`L() L()
`CD
`CD
`
`LL LL
`
`Page 4 of 11
`
`

`

`
`
`Patent Application Publication Oct. 7, 2004 Sheet 4 of 5 Patent Application Publication Oct. 7, 2004 Sheet 4 of 5
`
`US 2004/0196229 Al
`US 2004/0196229 Al
`
`FIG.6
`FIG.6
`
`8
`8
`
`RGB
`RGB
`
`Data Data
`In
`In
`
`-
`FRAME
`L...- FRAME
`MEMORY
`MEMORY
`\..61
`1\.61
`
`8
`8
`
`
`Fn ..... LOOK-UP Fn
`LOOK-UP
`Fn-1
`Fn-1
`
`TABLE TABLE
`I
`I
`
`8
`8
`
`62
`62
`
`
`RGB RGB
`• MData
`• MData
`Out
`Out
`
`Page 5 of 11
`
`

`

`
`
`Patent Application Publication Oct. 7,2004 Sheet 5 of 5 Patent Application Publication Oct. 7,2004 Sheet 5 of 5
`
`
`
`US 2004/0196229 Al US 2004/0196229 Al
`
`
`
`FIG.7A FIG.7A
`
`
`
`GRAY SCALE LEVEL GRAY SCALE LEVEL
`
`
`MVD MVD
`
`VD VD
`
`NORMALt--.'-_"---o NORMALt--.'-_"---o
`
`DATA DATA
`
`(RGB) (RGB)
`
`
`
`FIG.7B FIG.7B
`
`
`
`. GRAY SCALE LEVEL . GRAY SCALE LEVEL
`
`
`
`AMVD AMVD
`
`MODULATE
`MODULATE
`DATA
`DATA
`
`(AMdata) (AMdata)
`
`
`i i
`
`/ /
`
`
`
`FIG.7C FIG.7C
`
`
`
`G RAY SCALE LEVEL G RAY SCALE LEVEL
`
`MODULATE
`MODULATE
`DATA
`DATA
`
`(AMdata) (AMdata)
`
`
`BRIGHT(cid:173)BRIGHT(cid:173)
`
`NESS NESS
`
`
`BRIGHT(cid:173)BRIGHT(cid:173)
`
`NESS NESS
`
`
`BRIGHT(cid:173)BRIGHT(cid:173)
`
`NESS NESS
`
`
`I I
`
`'QSF I ESF I 'QSF I ESF I
`
`I I
`
`I I
`
`, ,
`
`:1 FRAME: :1 FRAME:
`
`TIME
`TIME
`
`
`
`JIJ VARIATION OF BRIGHTNESS BETWEEN MODULATION JIJ VARIATION OF BRIGHTNESS BETWEEN MODULATION
`
`SYSTEMS OF THE PRESENT INVENTION SYSTEMS OF THE PRESENT INVENTION
`
`AND CONVENTIONAL HIGH-SPEED DRIVING SYSTEM
`AND CONVENTIONAL HIGH-SPEED DRIVING SYSTEM
`
`Page 6 of 11
`
`

`

`
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`US 2004/0196229 Al US 2004/0196229 Al
`
`
`
`Oct. 7, 2004 Oct. 7, 2004
`
`
`
`1 1
`
`
`METHOD AND APPARATUS FOR DRIVING METHOD AND APPARATUS FOR DRIVING
`
`LIQUID CRYSTAL DISPLAY LIQUID CRYSTAL DISPLAY
`
`
`appears from the moving picture and a display quality is appears from the moving picture and a display quality is
`
`deteriorated in the LCD due to a reduction in a contrast ratio. deteriorated in the LCD due to a reduction in a contrast ratio.
`
`
`[0001] This application claims the benefit of Korean [0001] This application claims the benefit of Korean
`
`Application No. P2001-54127 filed on Sep. 4, 2001, which Application No. P2001-54127 filed on Sep. 4, 2001, which
`
`is hereby incorporated by reference. is hereby incorporated by reference.
`
`BACKGROUND OF THE INVENTION
`BACKGROUND OF THE INVENTION
`
`
`
`[0002] 1. Field of the Invention [0002] 1. Field of the Invention
`
`
`[0003] The present invention relates to a liquid crystal [0003] The present invention relates to a liquid crystal
`
`display, and more particularly, to a method and apparatus for display, and more particularly, to a method and apparatus for
`
`driving a liquid crystal display. Although the present inven(cid:173)driving a liquid crystal display. Although the present inven(cid:173)
`
`tion is suitable for a wide scope of applications, it is tion is suitable for a wide scope of applications, it is
`
`particularly suitable for enhancing a picture quality. particularly suitable for enhancing a picture quality.
`
`
`
`[0004] 2. Discussion of the Related Art [0004] 2. Discussion of the Related Art
`
`[0005] Generally, a liquid crystal display (LCD) controls
`[0005] Generally, a liquid crystal display (LCD) controls
`a light transmittance of each liquid crystal cell in accordance
`a light transmittance of each liquid crystal cell in accordance
`
`with a video signal, thereby displaying a picture. An active with a video signal, thereby displaying a picture. An active
`
`matrix LCD including a switching device for each liquid matrix LCD including a switching device for each liquid
`
`crystal cell is suitable for displaying a dynamic image. The crystal cell is suitable for displaying a dynamic image. The
`
`active matrix LCD uses a thin film transistor (TF1) as a active matrix LCD uses a thin film transistor (TF1) as a
`
`switching device. switching device.
`
`[0006] The LCD has a disadvantage in that it has a slow
`[0006] The LCD has a disadvantage in that it has a slow
`response time due to inherent characteristics of a liquid
`response time due to inherent characteristics of a liquid
`
`crystal, such as a viscosity and an elasticity, etc. Such crystal, such as a viscosity and an elasticity, etc. Such
`characteristics can be explained by using the following
`characteristics can be explained by using the following
`equations (1) and (2):
`equations (1) and (2):
`
`
`
`(1) (1)
`
`
`[0007] where 1:, represents a rising time when a voltage is [0007] where 1:, represents a rising time when a voltage is
`
`applied to a liquid crystal, Va is an applied voltage, V F applied to a liquid crystal, Va is an applied voltage, V F
`
`represents a Freederick transition voltage at which liquid represents a Freederick transition voltage at which liquid
`
`crystal molecules begin to perform an inclined motion, d is crystal molecules begin to perform an inclined motion, d is
`
`a cell gap of the liquid crystal cells, and y represents a a cell gap of the liquid crystal cells, and y represents a
`
`rotational viscosity of the liquid crystal molecules. rotational viscosity of the liquid crystal molecules.
`
`
`
`(2) (2)
`
`
`[0008] where 1:£ represents a falling time at which a liquid [0008] where 1:£ represents a falling time at which a liquid
`
`crystal is returned into the initial position by an elastic crystal is returned into the initial position by an elastic
`
`restoring force after a voltage applied to the liquid crystal restoring force after a voltage applied to the liquid crystal
`
`was turned off, and K is an elastic constant. was turned off, and K is an elastic constant.
`
`[0009] A twisted nematic (TN) mode liquid crystal has a
`[0009] A twisted nematic (TN) mode liquid crystal has a
`
`different response time due to physical characteristics of the different response time due to physical characteristics of the
`
`liquid crystal and a cell gap, etc. Typically, the TN mode liquid crystal and a cell gap, etc. Typically, the TN mode
`
`liquid crystal has a rising time of 20 to 80 ms and a falling liquid crystal has a rising time of 20 to 80 ms and a falling
`
`time of 20 to 30 ms. Since such a liquid crystal has a time of 20 to 30 ms. Since such a liquid crystal has a
`
`response time longer than one frame interval (i.e., 16.67 ms response time longer than one frame interval (i.e., 16.67 ms
`
`in the case of NTSC system) of a moving picture, a voltage in the case of NTSC system) of a moving picture, a voltage
`
`charged in the liquid crystal cell is progressed into the next charged in the liquid crystal cell is progressed into the next
`
`frame prior to arriving at a target voltage. Thus, due to a frame prior to arriving at a target voltage. Thus, due to a
`
`motion-blurring phenomenon a screen is blurred out at the motion-blurring phenomenon a screen is blurred out at the
`
`moving picture. moving picture.
`
`
`[0010] Referring to FIG. 1, the conventional LCD cannot [0010] Referring to FIG. 1, the conventional LCD cannot
`
`express desired color and brightness. Upon implementation express desired color and brightness. Upon implementation
`
`of a moving picture, a display brightness BL fails to arrive of a moving picture, a display brightness BL fails to arrive
`
`at a target brightness corresponding to a change of the video at a target brightness corresponding to a change of the video
`
`data VD from one level to another level due to its slow data VD from one level to another level due to its slow
`
`response time. Accordingly, a motion-blurring phenomenon response time. Accordingly, a motion-blurring phenomenon
`
`
`[0011]
`In order to overcome such a slow response time of In order to overcome such a slow response time of
`[0011]
`
`the LCD, U.S. Pat. No. 5,495,265 and PCT International the LCD, U.S. Pat. No. 5,495,265 and PCT International
`
`Publication No. W099/05567 have suggested to modulate Publication No. W099/05567 have suggested to modulate
`
`data in accordance with a difference in the data by using a data in accordance with a difference in the data by using a
`
`look-up table (hereinafter referred to as high-speed driving look-up table (hereinafter referred to as high-speed driving
`
`method). This high-speed driving method allows data to be method). This high-speed driving method allows data to be
`
`modulated by a principle as shown in FIG. 2. modulated by a principle as shown in FIG. 2.
`
`
`[0012] Referring to FIG. 2, a conventional high-speed [0012] Referring to FIG. 2, a conventional high-speed
`
`driving method modulates input data VD and applies the driving method modulates input data VD and applies the
`
`modulated data MVD to the liquid crystal cell, thereby modulated data MVD to the liquid crystal cell, thereby
`
`obtaining a desired brightness MBL. This high-speed driv(cid:173)obtaining a desired brightness MBL. This high-speed driv(cid:173)
`
`ing method increases IVa2-V/1 from the above equation (1) ing method increases IVa2-V/1 from the above equation (1)
`
`on the basis of a difference in the data so that a desired on the basis of a difference in the data so that a desired
`
`brightness can be obtained in response to a brightness value brightness can be obtained in response to a brightness value
`
`of the input data within one frame interval, thereby rapidly of the input data within one frame interval, thereby rapidly
`
`reducing a response time of the liquid crystal. Accordingly, reducing a response time of the liquid crystal. Accordingly,
`
`the LCD employing such a high-speed driving method the LCD employing such a high-speed driving method
`
`compensates for a slow response time of the liquid crystal by compensates for a slow response time of the liquid crystal by
`
`modulating a data value in order to alleviate a motion(cid:173)modulating a data value in order to alleviate a motion(cid:173)
`
`blurring phenomenon in a moving picture, thereby display(cid:173)blurring phenomenon in a moving picture, thereby display(cid:173)
`
`ing a picture at desired color and brightness. ing a picture at desired color and brightness.
`
`In other words, the high-speed driving method
`[0013]
`In other words, the high-speed driving method
`[0013]
`detects a variation in most significant bit data through a
`detects a variation in most significant bit data through a
`comparison of most significant bit data MSB of a current comparison of most significant bit data MSB of a current
`
`
`frame Fn with most significant bit data MSB of the previous frame Fn with most significant bit data MSB of the previous
`
`frame Fn-1. If the variation in the most significant bit data frame Fn-1. If the variation in the most significant bit data
`
`MSB is detected, a modulated data corresponding to the MSB is detected, a modulated data corresponding to the
`
`variation is selected from a look-up table so that the most variation is selected from a look-up table so that the most
`
`significant bit data MSB is modulated as shown in FIG. 3. significant bit data MSB is modulated as shown in FIG. 3.
`
`The high-speed driving method modulates only a part of the The high-speed driving method modulates only a part of the
`
`most significant bits among the input data for reducing a most significant bits among the input data for reducing a
`
`memory capacity. For example, the high-speed driving memory capacity. For example, the high-speed driving
`
`method can be implemented as shown in FIG. 4. method can be implemented as shown in FIG. 4.
`
`
`[0014] Referring to FIG. 4, a conventional high-speed [0014] Referring to FIG. 4, a conventional high-speed
`
`driving apparatus includes a frame memory 43 connected to driving apparatus includes a frame memory 43 connected to
`
`a most significant bit output bus line 42 and a look-up table a most significant bit output bus line 42 and a look-up table
`
`44 connected to the most significant bit output bus line 42 44 connected to the most significant bit output bus line 42
`
`and an output terminal of the frame memory 43. and an output terminal of the frame memory 43.
`
`[0015] The frame memory 43 stores most significant bit
`[0015] The frame memory 43 stores most significant bit
`data MSB during one frame period and supplies the stored
`data MSB during one frame period and supplies the stored
`data to the look-up table 44. Herein, the most significant bit
`data to the look-up table 44. Herein, the most significant bit
`
`data MSB are high-order 4 bits among 8 bits of the source data MSB are high-order 4 bits among 8 bits of the source
`
`data RGB. data RGB.
`
`
`[0016] The look-up table 44 makes a mapping of the most [0016] The look-up table 44 makes a mapping of the most
`
`significant bit data of the current frame Fn inputted from the significant bit data of the current frame Fn inputted from the
`
`most significant bit output bus line 42 and the most signifi(cid:173)most significant bit output bus line 42 and the most signifi(cid:173)
`
`cant bit data of the previous frame Fn-l inputted from the cant bit data of the previous frame Fn-l inputted from the
`
`frame memory 43 into a modulation data table such as Table frame memory 43 into a modulation data table such as Table
`
`1 to select modulated most significant bit data Mdata. Such 1 to select modulated most significant bit data Mdata. Such
`
`modulated most significant bit data Mdata are added to an modulated most significant bit data Mdata are added to an
`
`non-modulated least significant bit data LSB from a least non-modulated least significant bit data LSB from a least
`
`significant bit output bus line 41 before outputting to a liquid significant bit output bus line 41 before outputting to a liquid
`
`crystal display. crystal display.
`
`Page 7 of 11
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`

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`US 2004/0196229 Al US 2004/0196229 Al
`
`
`
`Oct. 7, 2004 Oct. 7, 2004
`
`2
`2
`
`
`
`TABLE 1 TABLE 1
`
`
`
`0 0
`
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`
`0 0
`0
`0
`
`0 0
`
`0 0
`
`0
`0
`
`
`2 2
`
`3 3
`
`4 4
`
`5 5
`
`
`7 7
`8
`8
`
`9 9
`10
`10
`
`11 11
`
`12 12
`
`13 13
`
`14 14
`
`15 15
`
`
`
`3 3
`
`4
`4
`4
`4
`4
`4
`3
`3
`3
`3
`2
`2
`2
`2
`2
`2
`2
`2
`2
`2
`2
`2
`2
`2
`
`2 2
`2
`2
`
`2 2
`
`
`
`2 2
`
`3
`3
`3
`3
`2
`2
`
`
`
`0 0
`
`
`
`4 4
`
`5
`5
`5
`5
`5
`5
`5
`5
`4
`4
`3
`3
`3
`3
`3
`3
`3
`3
`3
`3
`3
`3
`3
`3
`
`3 3
`3
`3
`
`3 3
`
`2 2
`
`
`
`5 5
`
`
`6 6
`5
`5
`4
`4
`4
`4
`4
`4
`4
`4
`4
`4
`4
`4
`
`4 4
`3
`3
`
`3 3
`
`3 3
`
`
`
`7 7
`
`9
`9
`8
`8
`8
`8
`8
`8
`
`8 8
`8
`8
`
`8 8
`7
`7
`
`
`6 6
`5
`5
`
`5 5
`
`4 4
`
`
`
`8 8
`
`
`
`9 9
`
`
`
`10 11 10 11
`
`
`
`12 13 14 15 12 13 14 15
`
`
`10 12 13 14 15 10 12 13 14 15
`
`10 12 13 14 15 10 12 13 14 15
`
`10 12 13 14 15 10 12 13 14 15
`
`10 11 13 14 15 10 11 13 14 15
`
`9 11 12 13 14 9 11 12 13 14
`
`9 11 12 13 14 9 11 12 13 14
`
`9 10 12 13 14 9 10 12 13 14
`9 10 11 13 14
`9 10 11 13 14
`
`8 10 11 12 14 8 10 11 12 14
`7
`
`9 11 12 13 9 11 12 13
`7
`7
`
`8 10 12 13 8 10 12 13
`7
`7
`8
`9 11 13
`7
`8
`9 11 13
`
`7 7
`
`8 8
`
`9 10 12 9 10 12
`7
`
`8 10 11 8 10 11
`7
`
`7 7
`
`
`8 8
`9 11 9 11
`
`7 7
`
`
`8 8
`9 9
`
`
`6 6
`
`5 5
`
`
`15 15
`
`15 15
`
`15 15
`
`15 15
`
`15 15
`
`15 15
`
`15 15
`
`15 15
`
`15 15
`
`14 14
`
`14 14
`
`14 14
`
`14 14
`
`13 13
`
`12 12
`
`11 11
`
`
`15 15 15 15
`
`15 15 15 15
`
`15 15 15 15
`
`15 15 15 15
`
`15 15 15 15
`
`15 15 15 15
`
`15 15 15 15
`
`15 15 15 15
`
`15 15 15 15
`
`15 15 15 15
`
`15 15 15 15
`
`15 15 15 15
`
`15 15 15 15
`
`15 15 15 15
`
`14 15 14 15
`
`13 15 13 15
`
`7
`7
`7
`7
`7
`7
`7
`7
`
`7 7
`7
`7
`
`6 6
`5
`5
`5
`5
`5
`5
`5
`5
`5
`5
`
`5 5
`4
`4
`
`4 4
`
`3 3
`
`2
`2
`
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`0
`
`0 0
`0
`0
`
`0 0
`
`0 0
`
`
`
`[0017] [0017]
`In the above Table 1, a left column is for a data In the above Table 1, a left column is for a data
`
`voltage VDn-1 of the previous frame Fn-1 while an upper(cid:173)voltage VDn-1 of the previous frame Fn-1 while an upper(cid:173)
`
`most row is for a voltage VDn of the current frame Fn. most row is for a voltage VDn of the current frame Fn.
`
`
`a data provider alternatively applying the modulated data a data provider alternatively applying the modulated data
`
`and data different from the modulated data to the liquid and data different from the modulated data to the liquid
`
`crystal panel within one frame period. crystal panel within one frame period.
`
`[0018] Such a conventional high-speed driving method
`[0018] Such a conventional high-speed driving method
`enhances a dynamic contrast ratio in comparison with a
`enhances a dynamic contrast ratio in comparison with a
`conventional normal driving method that does not modulate
`conventional normal driving method that does not modulate
`the source data. However, the conventional high-speed driv(cid:173)
`the source data. However, the conventional high-speed driv(cid:173)
`ing method gradually enhances brightness so that a desired
`ing method gradually enhances brightness so that a desired
`
`brightness level is achieved at the end of one frame period. brightness level is achieved at the end of one frame period.
`
`Due to this, in the conventional high-speed driving method, Due to this, in the conventional high-speed driving method,
`
`the dynamic contrast ratio cannot be reached at a desired the dynamic contrast ratio cannot be reached at a desired
`
`level. Furthermore, a color represented by combining red, level. Furthermore, a color represented by combining red,
`
`green, and blue is distorted when those colors are repro(cid:173)green, and blue is distorted when those colors are repro(cid:173)
`
`duced. duced.
`
`SUMMARY OF THE INVENTION
`SUMMARY OF THE INVENTION
`
`
`[0019] Accordingly, the present invention is directed to a [0019] Accordingly, the present invention is directed to a
`
`method and apparatus for driving a liquid crystal display that method and apparatus for driving a liquid crystal display that
`
`substantially obviates one or more of problems due to substantially obviates one or more of problems due to
`
`limitations and disadvantages of the related art. limitations and disadvantages of the related art.
`
`
`[0020] Another object of the present invention is to pro(cid:173)[0020] Another object of the present invention is to pro(cid:173)
`
`vide a method and apparatus for driving a liquid crystal vide a method and apparatus for driving a liquid crystal
`
`display that is adaptive for enhancing a picture quality. display that is adaptive for enhancing a picture quality.
`
`
`[0021] Additional features and advantages of the inven(cid:173)[0021] Additional features and advantages of the inven(cid:173)
`
`tion will be set forth in the description which follows and in tion will be set forth in the description which follows and in
`
`part will be apparent from the description, or may be learned part will be apparent from the description, or may be learned
`
`by practice of the invention. The objectives and other by practice of the invention. The objectives and other
`
`advantages of the invention will be realized and attained by advantages of the invention will be realized and attained by
`
`the structure particularly pointed out in the written descrip(cid:173)the structure particularly pointed out in the written descrip(cid:173)
`
`tion and claims hereof as well as the appended drawings. tion and claims hereof as well as the appended drawings.
`
`
`[0022] To achieve these and other advantages and in [0022] To achieve these and other advantages and in
`
`accordance with the purpose of the present invention, as accordance with the purpose of the present invention, as
`
`embodied and broadly described, a method of driving a embodied and broadly described, a method of driving a
`
`liquid crystal display includes modulating source data using liquid crystal display includes modulating source data using
`
`registered data previously provided and supplying the modu-registered data previously provided and supplying the modu-
`
`1ated data to a liquid crystal panel at an initial period of one 1ated data to a liquid crystal panel at an initial period of one
`
`frame period, and applying data different from the modu(cid:173)frame period, and applying data different from the modu(cid:173)
`
`lated data to the liquid crystal panel at a later period of the lated data to the liquid crystal panel at a later period of the
`
`one frame period. one frame period.
`
`
`[0024]
`In a further aspect of the present invention, a liquid In a further aspect of the present invention, a liquid
`[0024]
`
`crystal display includes a liquid crystal display panel dis(cid:173)crystal display includes a liquid crystal display panel dis(cid:173)
`
`playing images and having a plurality of data lines and a playing images and having a plurality of data lines and a
`
`plurality of scanning lines thereon, a modulator modulating plurality of scanning lines thereon, a modulator modulating
`
`source data based on registered data previously provided source data based on registered data previously provided
`
`therein, and a data provided alternatively applying the therein, and a data provided alternatively applying the
`
`modulated source data and the source data to the liquid modulated source data and the source data to the liquid
`
`crystal panel through the data lines within one frame period. crystal panel through the data lines within one frame period.
`
`
`[0025]
`It is to be understood that both the foregoing It is to be understood that both the foregoing
`[0025]
`
`general description and the following detailed description general description and the following detailed description
`
`are exemplary and explanatory and are intended to provide are exemplary and explanatory and are intended to provide
`
`further explanation of the invention as claimed. further explanation of the invention as claimed.
`
`
`
`BRIEF DESCRIPTION OF THE DRAWINGS BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0026] The accompanying drawings, which are included
`[0026] The accompanying drawings, which are included
`
`to provide a further understanding of the invention and are to provide a further understanding of the invention and are
`
`incorporated in and constitute a part of this application, incorporated in and constitute a part of this application,
`
`illustrate embodiments of the invention and together with illustrate embodiments of the invention and together with
`
`the description serve to explain the principle of the inven(cid:173)the description serve to explain the principle of the inven(cid:173)
`
`tion. tion.
`
`[0027]
`[0027]
`
`In the drawings:
`In the drawings:
`
`
`[0028] FIG. 1 is a waveform diagram showing a bright(cid:173)[0028] FIG. 1 is a waveform diagram showing a bright(cid:173)
`
`ness variation of a data modulation according to a conven(cid:173)ness variation of a data modulation according to a conven(cid:173)
`
`tionalliquid crystal display driving method; tionalliquid crystal display driving method;
`
`
`[0029] FIG. 2 is a waveform diagram showing a bright(cid:173)[0029] FIG. 2 is a waveform diagram showing a bright(cid:173)
`
`ness variation of a data modulation according to a conven(cid:173)ness variation of a data modulation according to a conven(cid:173)
`
`tional high-speed driving method; tional high-speed driving method;
`
`
`[0030] FIG. 3 illustrates a modulation of most significant [0030] FIG. 3 illustrates a modulation of most significant
`
`bit data in the conventional high-speed driving apparatus bit data in the conventional high-speed driving apparatus
`
`using 8 bits data; using 8 bits data;
`
`
`[0031] FIG. 4 is a block diagram showing a configuration [0031] FIG. 4 is a block diagram showing a configuration
`
`of a conventional high-speed driving apparatus for a liquid of a conventional high-speed driving apparatus for a liquid
`
`crystal display; crystal display;
`
`
`[0023]
`In another aspect of the present invention, an In another aspect of the present invention, an
`[0023]
`
`apparatus for driving a liquid crystal display includes a apparatus for driving a liquid crystal display includes a
`
`modulator modulating source data using registered data, and modulator modulating source data using registered data, and
`
`
`[0032] FIG. 5 is a block diagram showing a configuration [0032] FIG. 5 is a block diagram showing a configuration
`
`of a driving apparatus for a liquid crystal display according of a driving apparatus for a liquid crystal display according
`
`to the present invention; to the present invention;
`
`Page 8 of 11
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`

`

`
`
`US 2004/0196229 Al US 2004/0196229 Al
`
`
`
`Oct. 7, 2004 Oct. 7, 2004
`
`
`
`3 3
`
`
`[0033] FIG. 6 is a block diagram for a data modulator of [0033] FIG. 6 is a block diagram for a data modulator of
`
`FIG. 5; and FIG. 5; and
`
`
`[0034] FIGS. 7A and 7B are graphic diagrams respec(cid:173)[0034] FIGS. 7A and 7B are graphic diagrams respec(cid:173)
`
`tively showing modulated data and brightness of the con(cid:173)tively showing modulated data and brightness of the con(cid:173)
`
`ventional high-speed driving and the present invention, and ventional high-speed driving and the present invention, and
`
`FIG. 7C is a graphic diagram illustrating an improvement FIG. 7C is a graphic diagram illustrating an improvement
`
`indicated by a dark area. indicated by a dark area.
`
`
`DETAILED DESCRIPTION OF IRE DETAILED DESCRIPTION OF IRE
`
`ILLUSTRATED EMBODIMENTS ILLUSTRATED EMBODIMENTS
`
`
`[0035] Reference will now be made in detail to the illus(cid:173)[0035] Reference will now be made in detail to the illus(cid:173)
`
`trated embodiments of the present invention, examples of trated embodiments of the present invention, examples of
`
`which are illustrated in the accompanying drawings. Wher(cid:173)which are illustrated in the accompanying drawings. Wher(cid:173)
`
`ever possible, the same reference numbers will be used ever possible, the same reference numbers will be used
`
`throughout the drawings to refer to the same or like parts. throughout the drawings to refer to the same or like parts.
`
`
`[0036] FIG. 5 is a schematic diagram for a driving appa(cid:173)[0036] FIG. 5 is a schematic diagram for a driving appa(cid:173)
`
`ratus for a liquid crystal display (LCD) according to the ratus for a liquid crystal display (LCD) according to the
`
`present invention. present invention.
`
`[0037] The LCD driving apparatus includes a liquid crys(cid:173)
`[0037] The LCD driving apparatus includes a liquid crys(cid:173)
`
`tal display panel 57 having a plurality of data lines 55 and tal display panel 57 having a plurality of data lines 55 and
`
`a plurality of gate lines 56 crossing each other and having a plurality of gate lines 56 crossing each other and having
`
`TFT's provided at each intersection to drive liquid crystal TFT's provided at each intersection to drive liquid crystal
`
`cells Cle. A data driver 53 supplies data to the data lines 55 cells Cle. A data driver 53 supplies data to the data lines 55
`
`of the liquid crystal display panel 57. A gate driver 54 of the liquid crystal display panel 57. A gate driver 54
`
`applies a scanning pulse to the gate lines 56 of the liquid applies a scanning pulse to the gate lines 56 of the liquid
`
`crystal display panel 57. A timing controller 51 receives crys