WO2012124309A1 - Dispositif d'affichage à cristaux liquides et appareil électronique - Google Patents

Dispositif d'affichage à cristaux liquides et appareil électronique Download PDF

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Publication number
WO2012124309A1
WO2012124309A1 PCT/JP2012/001700 JP2012001700W WO2012124309A1 WO 2012124309 A1 WO2012124309 A1 WO 2012124309A1 JP 2012001700 W JP2012001700 W JP 2012001700W WO 2012124309 A1 WO2012124309 A1 WO 2012124309A1
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Prior art keywords
electrode
liquid crystal
crystal display
gate
display device
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PCT/JP2012/001700
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English (en)
Japanese (ja)
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泰 高丸
耕平 田中
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シャープ株式会社
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Publication of WO2012124309A1 publication Critical patent/WO2012124309A1/fr

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
    • G02F1/1362—Active matrix addressed cells
    • G02F1/1368—Active matrix addressed cells in which the switching element is a three-electrode device
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F2202/00—Materials and properties
    • G02F2202/10—Materials and properties semiconductor
    • G02F2202/103—Materials and properties semiconductor a-Si
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3614—Control of polarity reversal in general
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3648—Control of matrices with row and column drivers using an active matrix
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
    • H01L29/40—Electrodes ; Multistep manufacturing processes therefor
    • H01L29/41—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions
    • H01L29/417—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions carrying the current to be rectified, amplified or switched
    • H01L29/41725—Source or drain electrodes for field effect devices
    • H01L29/41733—Source or drain electrodes for field effect devices for thin film transistors with insulated gate

Definitions

  • the present invention relates to a liquid crystal display device and an electronic apparatus including the same.
  • liquid crystal display devices are widely used as display devices.
  • the 1H line inversion driving method is a driving method in which the polarity of all source signals is inverted every 1H period (one horizontal scanning period).
  • this driving method the polarity of all signal lines becomes positive when scanning a certain scanning line, and the polarity of all signal lines is inverted and becomes negative when scanning the next scanning line.
  • each pixel is alternately arranged with a row in which a positive signal is written in one horizontal row and a row in which a negative signal is written in one horizontal row. It becomes.
  • the 1H dot inversion driving method is a driving method in which the polarities of the signal lines are alternately inverted.
  • this driving method when a certain scanning line is scanned, the polarity of a certain signal line becomes positive, and the polarity of the adjacent signal line becomes negative.
  • the next scanning line is scanned, the polarity of the signal line is inverted and becomes negative, and the polarity of the adjacent signal line becomes positive.
  • the AC drive type liquid crystal display device displays a flicker pattern on the screen for the purpose of suppressing flicker, and generates a signal voltage and a common electrode voltage.
  • Initial adjustment is known. For example, a display state such as pseudo halftone frame inversion driving is displayed on a flicker pattern display screen in which one polarity pixel is displayed in black (or white display) and the other polarity pixel is displayed in halftone. In this state, the voltage applied to the common electrode is adjusted so that the flicker is minimized.
  • FIG. 21 is a plan view showing a TFT (thin film transistor) 100 used in a conventional liquid crystal display device
  • the TFT 100 has a U-shaped source electrode 102 having a pair of electrode limbs 101 formed in a bifurcated shape.
  • the drain electrode 103 disposed between the pair of electrode limbs 101, and the semiconductor layer 104 and the gate electrode 105 overlapping with the source electrode 102 and the drain electrode 103, thereby reducing the W length of the channel region 106. It is known to ensure a large amount (see Patent Documents 5 and 6, etc.).
  • TFTs used in liquid crystal display devices are usually formed of a-Si (amorphous silicon).
  • a photocurrent is generated, and an off-leakage current is generated.
  • the present inventors have made an AC drive for inverting the polarity of a signal voltage applied to a source electrode in a liquid crystal display device having a TFT having a source electrode shape different from that of a drain electrode, such as the TFT having the U-shaped source electrode.
  • a drain electrode such as the TFT having the U-shaped source electrode.
  • the present invention has been made in view of such a point, and the object of the present invention is to significantly reduce flicker while AC driving a liquid crystal display device having a TFT whose source electrode shape is different from that of the drain electrode. It is in trying to suppress.
  • a liquid crystal display device includes a plurality of source lines, a plurality of gate lines crossing the source lines, a plurality of pixels provided in a matrix, A thin film transistor provided in each of a plurality of pixels and connected to the source wiring and the gate wiring, a pixel electrode provided in each of the plurality of pixels and connected to a drain electrode of the thin film transistor, and at least one of the gate wirings
  • An AC drive control unit that reverses the polarity of the signal voltage applied to the plurality of source wirings for each scanning period is provided.
  • a pixel column composed of the plurality of pixels arranged along the gate wiring includes a plurality of first pixels in which the first thin film transistor is formed and a plurality of second pixels in which the second thin film transistor is formed. Yes.
  • flicker can be significantly suppressed while AC driving a liquid crystal display device having a TFT whose source electrode shape is different from that of the drain electrode.
  • FIG. 1 is an enlarged plan view showing a part of the TFT substrate according to the first embodiment.
  • FIG. 2 is an enlarged plan view showing the first TFT and the second TFT.
  • FIG. 3 is a plan view schematically showing a flicker pattern.
  • FIG. 4 is a cross-sectional view showing a schematic configuration of the TFT.
  • FIG. 5 is a plan view schematically showing a TFT having a first electrode and a second electrode smaller than the first electrode.
  • FIG. 6 is a graph showing the results of Example 1.
  • FIG. 7 is a graph showing the results of Example 2.
  • FIG. 8 is a graph showing off-leakage currents in Examples 1 and 2.
  • FIG. 9 is a cross-sectional view illustrating a schematic structure of a liquid crystal display device provided in the electronic apparatus according to the first embodiment.
  • FIG. 10 is a plan view showing 1H line inversion driving of the liquid crystal display device according to the first embodiment.
  • FIG. 11 is a plan view showing 1H line inversion driving of a liquid crystal display device as a comparative example.
  • FIG. 12 is a graph showing a simulation result with respect to temporal change in luminance in the comparative example.
  • FIG. 13 is a graph illustrating a simulation result of a change in luminance with time in the example.
  • FIG. 14 is an enlarged plan view showing a part of the TFT substrate according to the second embodiment.
  • FIG. 10 is a plan view showing 1H line inversion driving of the liquid crystal display device according to the first embodiment.
  • FIG. 11 is a plan view showing 1H line inversion driving of a liquid crystal display device as a comparative example.
  • FIG. 12 is a graph showing a simulation result with respect
  • FIG. 15 is a plan view showing 1H dot inversion driving of the liquid crystal display device according to the second embodiment.
  • FIG. 16 is a plan view showing 1H dot inversion driving of a liquid crystal display device as a comparative example.
  • FIG. 17 is a plan view showing an enlarged part of the TFT substrate 13 in the third embodiment.
  • FIG. 18 is an enlarged plan view showing the first TFT and the second TFT in the third embodiment.
  • FIG. 19 is a plan view showing 1H line inversion driving of the liquid crystal display device 1 according to the third embodiment.
  • FIG. 20 is a plan view showing 1H line inversion driving of a liquid crystal display device as a comparative example.
  • FIG. 21 is a plan view showing a TFT used in a conventional liquid crystal display device.
  • Embodiment 1 of the Invention 1 to 13 show Embodiment 1 of the present invention.
  • FIG. 1 is a plan view showing an enlarged part of the TFT substrate according to the first embodiment.
  • FIG. 2 is an enlarged plan view showing the first TFT and the second TFT.
  • FIG. 9 is a cross-sectional view illustrating a schematic structure of a liquid crystal display device provided in the electronic apparatus according to the first embodiment.
  • the electronic device 10 in the first embodiment is, for example, a liquid crystal television.
  • the electronic device 10 may be a mobile device such as a smartphone or a mobile phone, or other electronic device.
  • the electronic device 10 includes a liquid crystal display device 1 as a display unit inside a housing 2.
  • the liquid crystal display device 1 includes a liquid crystal display panel 11 and a backlight unit 12 that is a light source disposed on the back side of the liquid crystal display panel 11. That is, the liquid crystal display device 1 is configured to perform transmissive display by selectively transmitting at least light from the backlight unit 12.
  • the liquid crystal display panel 11 includes a TFT substrate 13 that is a first substrate, and a counter substrate 14 that is a second substrate disposed to face the TFT substrate 13.
  • a liquid crystal layer 15 is sealed between the TFT substrate 13 and the counter substrate 14 by a seal member 16.
  • the liquid crystal display panel 11 has a display area (not shown) and a frame-like non-display area (not shown) provided around the display area.
  • a plurality of pixels 18 provided in a matrix are formed in the display area.
  • the pixel 18 is a minimum unit for controlling display.
  • the TFT substrate 13 is composed of an active matrix substrate.
  • the TFT substrate 13 has a glass substrate (not shown) as a transparent substrate.
  • a plurality of source lines 23 extending in parallel with each other and a plurality of gate lines 22 extending so as to intersect the source lines 23 are formed on the glass substrate.
  • the plurality of gate lines 22 and the plurality of source lines 23 are formed in a lattice shape as a whole, and the pixels 18 are formed in regions surrounded by the gate lines 22 and the source lines 23 in a rectangular shape.
  • Each of the gate wiring 22 and the source wiring 23 is configured by a single-layer film made of one type or a multi-layer film made of a plurality of types, for example, among Al, Cu, Mo, Ti, and the like.
  • Each pixel 18 is provided with a TFT (thin film transistor) 20 in the vicinity of the intersection of the gate wiring 22 and the source wiring 23.
  • the gate wiring 22 and the source wiring 23 are connected to the TFT 20.
  • the TFT 20 in the first embodiment is a bottom gate type TFT, and a gate electrode 26 branched from the gate wiring 22 and a semiconductor layer (not shown) facing the gate electrode 26 via a gate insulating film (not shown).
  • a source electrode 25 that is branched from the source wiring 23, and a drain electrode 29.
  • the gate electrode 26 and the gate wiring 22 are formed on a glass substrate and covered with the gate insulating film.
  • the gate insulating film is composed of, for example, a single-layer film made of one of SiNx (silicon nitride) and SiO 2 or a multi-layer film made of a plurality of kinds.
  • the semiconductor layer is formed in a rectangular island shape, for example.
  • the semiconductor layer is formed of a semiconductor such as a-Si, for example.
  • a part of the source electrode 25 and a part of the drain electrode 29 are overlapped with the semiconductor layer and the gate electrode 26, respectively.
  • the source electrode 25, the drain electrode 29, and the like are covered with an interlayer insulating film (not shown).
  • the interlayer insulating film is made of, for example, SiNx.
  • the plurality of pixels 18 are formed with pixel electrodes 30 connected to the drain electrodes 29 of the TFTs 20 provided in the pixels 18.
  • the pixel electrode 30 is formed on the surface of the interlayer insulating film, and is composed of a transparent conductive film such as ITO (Indium Tin Oxide).
  • a common electrode (not shown) provided in common with the plurality of pixel electrodes 30 is formed on the counter substrate 14. Similar to the pixel electrode 30, the common electrode is also formed of a transparent conductive film such as ITO. Thus, the orientation of the liquid crystal layer 15 is controlled for each pixel 18 by controlling the potential difference between the common electrode having a predetermined potential and the pixel electrode 30 of each pixel 18.
  • the TFT 20 in this embodiment includes a first TFT 20 a in which the source electrode 25 is larger than the drain electrode 29 and a second TFT 20 b in which the drain electrode 29 is larger than the source electrode 25.
  • the source electrode 25 of the first TFT 20 a includes a pair of electrode limbs 32 formed in a bifurcated shape, and a base end portion 33 formed wide on the base end side of the electrode limbs 32. have.
  • the drain electrode 29 of the first TFT 20 a has a linear portion 34 extending linearly, and the tip of the linear portion 34 is disposed between the pair of electrode limbs 32.
  • the entire electrode limb 32 of the source electrode 25 and a part of the base end portion 33 overlap the gate electrode 26.
  • the overlapping width A of the source electrode 25 and the gate electrode 26 at the base end portion 33 is wider than the overlapping width B of the drain electrode 29 and the gate electrode 26.
  • the drain electrode 29 of the second TFT 20b has a pair of electrode limbs 36 formed in a bifurcated shape and a base end portion 37 formed wide on the base end side of the electrode limbs 36.
  • the source electrode 25 of the second TFT 20 b has a linear portion 38 that extends linearly, and the tip of the linear portion 38 is disposed between the pair of electrode limbs 36.
  • the entire electrode limb 36 of the drain electrode 29 and a part of the base end portion 37 overlap the gate electrode 26.
  • the overlap width A between the source electrode 25 and the gate electrode 26 is narrower than the overlap width B between the drain electrode 29 and the gate electrode 26 at the base end portion 37.
  • ⁇ Pixel arrangement configuration> As shown in FIG. 1, a plurality of first pixels 18 a in which first TFTs 20 a are formed and a plurality of pixels in which second TFTs 20 b are formed are arranged in a pixel column 19 including a plurality of pixels 18 arranged along the gate wiring 22. The second pixel 18b is included.
  • each pixel column 19 one first pixel 18 a and one second pixel 18 b are alternately arranged along the gate wiring 22.
  • a plurality of first pixels 18a or a plurality of second pixels 18b are arranged side by side.
  • first pixel 18 a and the second pixel 18 b for example, in each pixel column 19, two first pixels 18 a and two second pixels 18 b are alternately arranged along the gate wiring 22. May be arranged. That is, at least one first pixel 18 a and the same number of second pixels 18 b as the at least one first pixel 18 a are alternately arranged along the gate wiring 22 in the pixel column 19. Also good.
  • the liquid crystal display device 1 further includes an AC drive control unit 40 that applies signal voltages having the same polarity to the plurality of source lines 23 during a period of scanning one gate line 22.
  • the AC drive control unit 40 is configured to invert the polarity of the signal voltage applied to the plurality of source lines 23 for each period of scanning one gate line 22. That is, the driving method of the liquid crystal display device 1 is a 1H line inversion driving method in which the polarity of the signal voltage is inverted every 1H period (one horizontal scanning period).
  • the AC drive control unit 40 may be configured to invert the polarity of the signal voltage every time the plurality of gate wirings 22 are scanned. That is, the AC drive control unit 40 may be configured to perform nH line inversion driving. Therefore, the AC drive control unit 40 can be configured to apply signal voltages having the same polarity to the plurality of source lines 23 in each of the periods in which at least one gate line 22 is scanned.
  • the liquid crystal display device 1 is a liquid crystal display panel in which a TFT substrate 13 manufactured by forming a plurality of TFTs 20 and the like and a counter substrate 14 formed with a common electrode and the like are bonded together via a liquid crystal layer 15 and a seal member 16. 11 and the backlight unit 12 is disposed opposite to the liquid crystal display panel 11. Further, the electronic apparatus 10 is manufactured by incorporating the liquid crystal display device 1 into the housing 2 together with other functional circuits and the like.
  • a flicker pattern is displayed on the screen for the purpose of suppressing flickering on the liquid crystal display panel 11 with the backlight unit 12 facing each other, and the signal voltage and the common electrode voltage are initially adjusted. Voltage adjusting step is included.
  • FIG. 3 is a plan view schematically showing a flicker pattern.
  • the flicker pattern 42 is a pattern in which the pixel 18 to which a signal voltage of one polarity is applied is displayed in black (Black), and the pixel 18 in the other polarity is displayed in halftone (Gray). is there. Since the flicker pattern 42 is a display pattern in which flicker is most easily recognized on the display screen, the flicker pattern 42 is used as a display pattern when adjusting the voltage (common electrode voltage) applied to the common electrode in the counter substrate 14.
  • the flicker pattern 42 in the present embodiment is a stripe pattern in which the pixel columns 19 displayed in black and the pixel columns 19 displayed in halftone are alternately arranged one by one. .
  • the polarity of the signal voltage in each pixel column 19 is inverted for each frame. That is, the pixel column 19 in which the polarity of each pixel 18 in the n ⁇ 1 frame is “ ⁇ ...” Becomes “+++...” In the n frame and “ ⁇ . ⁇ ⁇
  • the magnitude of the common electrode voltage is adjusted so that the flicker on the display screen is minimized while the flicker pattern 42 is displayed on the display screen of the liquid crystal display device 1.
  • FIG. 4 is a cross-sectional view showing a schematic configuration of the TFT 20.
  • the TFT 20 includes a gate electrode 26 formed on the glass substrate 17, a gate insulating film 27 covering the gate electrode 26, and a semiconductor made of a-Si opposed to the center of the gate electrode 26. It has a layer 28, a source electrode 25 facing one end side of the gate electrode 26, and a drain electrode 29 facing the other end side of the gate electrode 26.
  • Part of the light of the backlight unit 12 passes through the glass substrate 17 and enters between the source electrode 25 or the drain electrode 29 and the gate electrode 26. Then, as indicated by an arrow in FIG. 4, the incident light repeatedly reflects between the source electrode 25 or the drain electrode 29 and the gate electrode 26 and enters the semiconductor layer 28. As a result, an off-leakage current is generated in the TFT 20.
  • FIG. 5 is a plan view schematically showing a TFT 50 having a first electrode 51 and a second electrode 52 smaller than the first electrode 51 as a source electrode or a drain electrode.
  • a semiconductor layer 54 is formed between the first electrode 51 and the second electrode 52.
  • the TFT 50 having the first electrode 51 formed in a U-shape and the second electrode 52 formed in an I-shape as a source electrode or a drain electrode will be described.
  • the L length of the semiconductor layer 54 is 4 ⁇ m and the W length is 50 ⁇ m.
  • the overlapping width D between the U-shaped first electrode 51 and the gate electrode 53 is 26 ⁇ m, and the overlapping width d between the I-shaped second electrode 52 and the gate electrode 53 is 6 ⁇ m.
  • a voltage of ⁇ 20 to 20 V was applied to the gate electrode.
  • the applied voltage to the drain electrode was 4.1V, and the applied voltage to the source electrode was 0V.
  • Example 1 the U-shaped first electrode 51 is used as a source electrode and the I-shaped second electrode 52 is used as a drain electrode, and light having an intensity of 1750 cd / m 2 is irradiated.
  • the state X1 and the dark state Y1 where no light is irradiated the change in drain current with respect to the gate voltage was measured. The measurement results are shown in the graph of FIG.
  • the light state X2 is irradiated with light having an intensity of 1750 cd / m 2.
  • the change in drain current with respect to the gate voltage was measured for the dark state Y2 where no light was irradiated. The measurement results are shown in the graph of FIG.
  • Example 1 and Example 2 in the dark states Y1 and Y2, as indicated by broken lines in FIGS. 6 and 7, since the light itself applied to the TFT 50 is small, the drain current value indicating the off-leakage current is relatively low. small.
  • Example 1 in the bright state X1, although the voltage applied to the I-shaped second electrode (drain current) 52 is larger than the U-shaped first electrode (source electrode) 51, the second electrode 52 Since the overlap width between the first electrode 51 and the gate electrode 53 is smaller than the overlap width between the first electrode 51 and the gate electrode 53, the off-leakage current is relatively small as shown by the solid line in FIG.
  • Example 2 in the bright state X2, the applied voltage to the U-shaped first electrode (drain electrode) 51 is larger than that of the I-shaped second electrode (source electrode) 52, and the application thereof Since the overlapping width between the U-shaped first electrode 51 and the gate electrode 53 having a large voltage is larger than the overlapping width between the second electrode 52 and the gate electrode 53, as shown by the solid line in FIG. It became relatively large.
  • the graph of FIG. 8 shows a comparison of the off-leakage current (drain current value) in Examples 1 and 2.
  • the off-leakage current X2 in the bright state X2 of Example 2 is larger than the off-leakage current X1 in the bright state X1 of Example 1.
  • the off-leakage current Y1 in the dark state Y1 of Example 1 and the off-leakage current Y2 in the dark state Y2 of Example 2 are substantially the same and smaller than X1 and X2.
  • the off-leakage current increases when a + polarity signal voltage is applied to the second electrode 52, while the off-leakage current decreases when the + polarity signal voltage is applied to the second electrode 52.
  • FIG. 10 is a plan view showing 1H line inversion driving of the liquid crystal display device 1 according to the first embodiment.
  • the signal voltage applied to the source line 23 is set to ⁇ polarity in the 1H period of scanning the pixel column 19 a for black display of a certain n ⁇ 1 frame.
  • the signal voltage applied to the source line 23 is inverted to have a positive polarity.
  • the arrow of each pixel 18 in FIG. 10 indicates the direction in which the off-leakage current flows.
  • the off-leak current of the first pixel 18a is relatively small (S)
  • the off-leak current of the second pixel 18b is relatively large. (L). Therefore, the same number of pixels with half-tone display on the entire screen includes the first pixel 18a having a relatively small off-leakage current (S) and the second pixel 18b having a relatively large off-leakage current (L).
  • the off-leak current of the first pixel 18a becomes relatively large (L), and the off-leak current of the second pixel 18b. Becomes relatively small (S). Therefore, the same number of pixels with half-tone display on the entire screen includes the first pixels 18a having a relatively large off-leakage current (L) and the second pixels 18b having a relatively small off-leakage current (S).
  • any frame as a result of including the same number of (S) pixels 18 having a relatively small off-leakage current and (L) pixels 18 having a relatively large off-leakage current. Since the total leak amount of the entire display screen is the same before and after the change, flicker can be significantly suppressed. Therefore, according to the present embodiment, flicker can be significantly suppressed while ensuring a large W length of each TFT 20.
  • FIG. 11 is a plan view showing 1H line inversion driving of a liquid crystal display device as a comparative example.
  • all the pixels 118 have the same configuration, and each source electrode 125 is formed in a U shape, while each drain electrode 129 is formed in an I shape.
  • the signal voltage applied to the source line 123 is set to -polarity in the 1H period during which the pixel column 119a for black display of a certain n-1 frame is scanned. To do. In the 1H period during which the next pixel row 119b for halftone display is scanned, the signal voltage applied to the source wiring 123 is inverted to have a positive polarity.
  • the arrow of each pixel 118 in FIG. 11 indicates the direction in which the off-leakage current flows.
  • the off-leak current of each pixel 118 is relatively small (S). Accordingly, the entire screen is displayed in halftone by the (S) pixel 118 having a relatively small off-leakage current.
  • the off-leak current of each pixel 118 is relatively large (L) in the pixel column 119b displaying halftone in the next n frames. Therefore, the entire screen is displayed in halftone by the (L) pixel 118 having a relatively large off-leakage current.
  • the off-leak current of all the pixels 118 that perform halftone display is relatively small (S) before and after the frame changes, and the off-leakage of all the pixels 118 that perform halftone display. Since the state where the current is relatively large (L) is alternately switched, the flicker is easily visually recognized.
  • FIG. 12 is a graph showing a simulation result with respect to a temporal change in luminance of the liquid crystal display device in the comparative example.
  • FIG. 13 is a graph showing a simulation result with respect to a temporal change in luminance of the liquid crystal display device 1 in the present embodiment.
  • the waveform of the luminance change has a distorted shape as shown in the graph of FIG.
  • the waveform in one frame period is symmetric as shown in the graph of FIG. It turns out that it will become a shape.
  • Embodiment 2 of the Invention >> 14 to 16 show Embodiment 2 of the present invention.
  • FIG. 14 is a plan view showing an enlarged part of the TFT substrate 13 in the second embodiment.
  • FIG. 15 is a plan view showing 1H dot inversion driving of the liquid crystal display device 1 according to the second embodiment.
  • FIG. 16 is a plan view showing 1H dot inversion driving of a liquid crystal display device as a comparative example.
  • the same portions as those in FIGS. 1 to 13 are denoted by the same reference numerals, and detailed description thereof is omitted.
  • the AC drive control unit 40 performs 1H line inversion drive.
  • the AC drive control unit 40 is not limited to this, and a plurality of AC drive control units 40 are provided for each period of scanning at least one gate wiring 22.
  • the polarity of the signal voltage applied to the source wiring 23 may be reversed.
  • the AC drive control unit 40 in the second embodiment is configured to perform 1H dot inversion drive.
  • the electronic device 10 includes a liquid crystal display device 1 as a display unit inside a housing 2 as shown in FIG.
  • the electronic device 10 is, for example, a mobile device such as a liquid crystal television or a smartphone or other electronic devices.
  • the liquid crystal display device 1 includes a liquid crystal display panel 11 and a backlight unit 12 that is a light source disposed on the back side of the liquid crystal display panel 11. That is, the liquid crystal display device 1 is configured to perform transmissive display by selectively transmitting at least light from the backlight unit 12.
  • the liquid crystal display panel 11 includes a TFT substrate 13 that is a first substrate, and a counter substrate 14 that is a second substrate disposed to face the TFT substrate 13.
  • a liquid crystal layer 15 is sealed between the TFT substrate 13 and the counter substrate 14 by a seal member 16.
  • the liquid crystal display panel 11 has a display area (not shown) and a frame-like non-display area (not shown) provided around the display area.
  • a plurality of pixels 18 provided in a matrix are formed in the display area.
  • the TFT substrate 13 is composed of an active matrix substrate.
  • the TFT substrate 13 has a glass substrate (not shown) as a transparent substrate.
  • a plurality of source lines 23 extending in parallel to each other and a plurality of gate lines 22 extending so as to cross the source lines 23 are formed on the glass substrate.
  • the plurality of gate lines 22 and the plurality of source lines 23 are formed in a lattice shape as a whole, and the pixels 18 are formed in regions surrounded by the gate lines 22 and the source lines 23 in a rectangular shape.
  • Each of the gate wiring 22 and the source wiring 23 is configured by a single-layer film made of one type or a multi-layer film made of a plurality of types, for example, among Al, Cu, Mo, Ti, and the like.
  • Each pixel 18 is provided with a TFT 20 in the vicinity of the intersection of the gate wiring 22 and the source wiring 23.
  • the gate wiring 22 and the source wiring 23 are connected to the TFT 20.
  • the TFT 20 in the second embodiment is a bottom gate type TFT, and a gate electrode 26 branched from the gate wiring 22 and a semiconductor layer (not shown) facing the gate electrode 26 via a gate insulating film (not shown).
  • the gate electrode 26 and the gate wiring 22 are formed on a glass substrate and covered with the gate insulating film.
  • the gate insulating film is composed of, for example, a single-layer film made of one of SiNx (silicon nitride) and SiO 2 or a multi-layer film made of a plurality of kinds.
  • the semiconductor layer is formed in a rectangular island shape, for example.
  • the semiconductor layer is formed of a semiconductor such as a-Si, for example.
  • a part of the source electrode 25 and a part of the drain electrode 29 are overlapped with the semiconductor layer and the gate electrode 26, respectively.
  • the source electrode 25, the drain electrode 29, and the like are covered with an interlayer insulating film (not shown).
  • the interlayer insulating film is made of, for example, SiNx.
  • the plurality of pixels 18 are formed with pixel electrodes 30 connected to the drain electrodes 29 of the TFTs 20 provided in the pixels 18.
  • the pixel electrode 30 is formed on the surface of the interlayer insulating film, and is formed of a transparent conductive film such as ITO.
  • a common electrode (not shown) provided in common with the plurality of pixel electrodes 30 is formed on the counter substrate 14. Similar to the pixel electrode 30, the common electrode is also formed of a transparent conductive film such as ITO. Thus, the orientation of the liquid crystal layer 15 is controlled for each pixel 18 by controlling the potential difference between the common electrode having a predetermined potential and the pixel electrode 30 of each pixel 18.
  • the TFT 20 in this embodiment includes a first TFT 20 a in which the source electrode 25 is larger than the drain electrode 29 and a second TFT 20 b in which the drain electrode 29 is larger than the source electrode 25.
  • the source electrode 25 of the first TFT 20 a includes a pair of electrode limbs 32 formed in a bifurcated shape, and a base end portion 33 formed wide on the base end side of the electrode limbs 32. have.
  • the drain electrode 29 of the first TFT 20 a has a linear portion 34 extending linearly, and the tip of the linear portion 34 is disposed between the pair of electrode limbs 32.
  • the entire electrode limb 32 of the source electrode 25 and a part of the base end portion 33 overlap the gate electrode 26.
  • the overlapping width A of the source electrode 25 and the gate electrode 26 at the base end portion 33 is wider than the overlapping width B of the drain electrode 29 and the gate electrode 26.
  • the drain electrode 29 of the second TFT 20b has a pair of electrode limbs 36 formed in a bifurcated shape and a base end portion 37 formed wide on the base end side of the electrode limbs 36.
  • the source electrode 25 of the second TFT 20 b has a linear portion 38 that extends linearly, and the tip of the linear portion 38 is disposed between the pair of electrode limbs 36.
  • the entire electrode limb 36 of the drain electrode 29 and a part of the base end portion 37 overlap the gate electrode 26.
  • the overlap width A between the source electrode 25 and the gate electrode 26 is narrower than the overlap width B between the drain electrode 29 and the gate electrode 26 at the base end portion 37.
  • a pixel column 19 including a plurality of pixels 18 arranged along the gate wiring 22 includes a plurality of first pixels 18 a in which the first TFTs 20 a are formed and a plurality of pixels in which the second TFTs 20 b are formed.
  • the second pixel 18b is included.
  • each pixel column 19 two first pixels 18 a and two second pixels 18 b are alternately arranged along the gate wiring 22.
  • a plurality of first pixels 18a or a plurality of second pixels 18b are arranged side by side.
  • the liquid crystal display device 1 further includes an AC drive control unit 40 that applies signal voltages having different polarities to the source lines 23 adjacent to each other in a period during which one gate line 22 is scanned.
  • the AC drive control unit 40 is configured to invert the polarity of the signal voltage applied to the plurality of source lines 23 for each period of scanning one gate line 22. That is, the driving method of the liquid crystal display device 1 is a 1H dot inversion driving method in which the polarity of the signal voltage is inverted every 1H period (one horizontal scanning period).
  • the AC drive control unit 40 may be configured to invert the polarity of the signal voltage every time the plurality of gate wirings 22 are scanned. That is, the AC drive control unit 40 may be configured to perform nH dot inversion driving. Therefore, the AC drive control unit 40 can be configured to apply signal voltages having different polarities to the source wirings 23 adjacent to each other in each of the scanning periods of at least one gate wiring 22.
  • the liquid crystal display device 1 is a liquid crystal display panel in which a TFT substrate 13 manufactured by forming a plurality of TFTs 20 and the like and a counter substrate 14 formed with a common electrode and the like are bonded together via a liquid crystal layer 15 and a seal member 16. 11 and the backlight unit 12 is disposed opposite to the liquid crystal display panel 11. Further, the electronic apparatus 10 is manufactured by incorporating the liquid crystal display device 1 into the housing 2 together with other functional circuits and the like.
  • a flicker pattern is displayed on the screen for the purpose of suppressing flickering on the liquid crystal display panel 11 with the backlight unit 12 facing each other, and the signal voltage and the common electrode voltage are initially adjusted. Voltage adjusting step is included.
  • the flicker pattern in the present embodiment has, for example, a black checkered pixel 18 and a halftone display pixel 18 arranged in a zigzag pattern, and has a checkered pattern as a whole.
  • the polarity of the signal voltage in each pixel column 19 is inverted for each frame. That is, the pixel column 19 in which the polarity of each pixel 18 in the n ⁇ 1 frame is “ ⁇ ++ ⁇ ...” Becomes “+ ⁇ + ⁇ ...” In the n frame and “ ⁇ ++ ⁇ ” in the n + 1 frame. + ... ".
  • the magnitude of the common electrode voltage is adjusted so that the flicker on the display screen is minimized while the flicker pattern 42 is displayed on the display screen of the liquid crystal display device 1.
  • the present inventors reverse the polarity of the signal voltage applied to the source electrode (source wiring) in a liquid crystal display device including a TFT having a source electrode shape different from that of the drain electrode. It was found that the amount of off-leakage current generated in the TFT changes according to the reversal of the polarity. As a result of the change in the luminance of the pixel provided with the TFT along with the change in the off-leakage current, it has been found that flicker is easily visually recognized.
  • FIG. 15 is a plan view showing 1H dot inversion driving of the liquid crystal display device 1 according to the second embodiment.
  • the liquid crystal display device 1 As shown in the upper part of FIG. 15, in the 1H period in which the pixel row 19 a that performs a certain “black display, halftone display, black display, halftone display...
  • the polarity of the signal voltage applied to the wiring 23 is “+ ⁇ + ⁇ .
  • the polarity of the signal voltage applied to the source wiring 23 is set to “ ⁇ ++ ⁇ + ⁇ for the pixel row 19b for“ halftone display, black display, halftone display, black display. ⁇ ⁇ ⁇
  • a positive polarity signal voltage is applied to the pixel 18 displaying black
  • a negative polarity signal voltage is applied to the pixel 18 displaying halftone.
  • the arrow of each pixel 18 in FIG. 15 indicates the direction in which the off-leakage current flows.
  • the off-leakage current is relatively large (L) in the first pixel 18a displaying the halftone display that is visually recognized.
  • the off-leakage current is relatively small in the second pixel 18b displaying halftone (S). Therefore, the same number of pixels with half-tone display on the entire screen includes the first pixels 18a having a relatively large off-leakage current (L) and the second pixels 18b having a relatively small off-leakage current (S).
  • the off-leakage current is relatively small in the first pixel 18a that is displayed as a halftone display (S).
  • the off-leakage current becomes relatively large (L) in the second pixel 18b displaying halftone. Therefore, the same number of pixels with half-tone display on the entire screen includes the first pixel 18a having a relatively small off-leakage current (S) and the second pixel 18b having a relatively large off-leakage current (L).
  • each frame includes the same number (S) of pixels 18 with relatively small off-leakage current (S) and pixels (L) with relatively large off-leakage current. Since the total leak amount of the entire display screen is the same before and after the change, flicker can be significantly suppressed. Therefore, according to the present embodiment, flicker can be significantly suppressed while ensuring a large W length of each TFT 20.
  • FIG. 16 is a plan view showing 1H dot inversion driving of a liquid crystal display device as a comparative example.
  • all the pixels 118 have the same configuration, and each source electrode 125 is formed in a U shape, while each drain electrode 129 is formed in an I shape.
  • the pixel column 119a that performs certain “black display, halftone display, black display, halftone display...
  • the polarity of the signal voltage applied to the source wiring 123 is “+ ⁇ + ⁇ .
  • the polarity of the signal voltage applied to the source wiring 123 is set to “ ⁇ ++ ⁇ + ⁇ for the pixel column 119b performing“ halftone display, black display, halftone display, black display. ⁇ ⁇ ⁇
  • a positive polarity signal voltage is applied to the pixel 118 displaying black
  • a negative polarity signal voltage is applied to the pixel 118 displaying halftone.
  • the arrow of each pixel 18 in FIG. 16 indicates the direction in which the off-leakage current flows.
  • the off-leakage current is relatively large (L) in the visually recognized pixel 118 displaying halftone. Therefore, the entire screen is displayed in halftone by the (L) pixel 118 having a relatively large off-leakage current.
  • the off-leakage current is relatively small in the pixel 118 that is displayed in halftone in the next n frames (S). Accordingly, the entire screen is displayed in halftone by the (S) pixel 118 having a relatively small off-leakage current.
  • the off-leak current of all the pixels 118 that perform halftone display is relatively large (L) before and after the frame changes, and the off-leakage of all the pixels 118 that perform halftone display. Since the state where the current is relatively small (S) is alternately switched, flicker is likely to be visually recognized.
  • Embodiment 3 of the Invention >> 17 to 20 show Embodiment 3 of the present invention.
  • FIG. 17 is a plan view showing an enlarged part of the TFT substrate 13 in the third embodiment.
  • FIG. 18 is an enlarged plan view showing the first TFT and the second TFT in the third embodiment.
  • the source electrode 25 or the drain electrode 29 of the TFT 20 is formed in a U shape, whereas in the third embodiment, the source electrode 25 and the drain electrode 29 of the TFT 20 are each formed in a rectangular shape. Is different.
  • the electronic device 10 includes a liquid crystal display device 1 as a display unit inside a housing 2 as shown in FIG.
  • the electronic device 10 is, for example, a mobile device such as a liquid crystal television or a smartphone or other electronic devices.
  • the liquid crystal display device 1 includes a liquid crystal display panel 11 and a backlight unit 12 that is a light source disposed on the back side of the liquid crystal display panel 11. That is, the liquid crystal display device 1 is configured to perform transmissive display by selectively transmitting at least light from the backlight unit 12.
  • the liquid crystal display panel 11 includes a TFT substrate 13 that is a first substrate, and a counter substrate 14 that is a second substrate disposed to face the TFT substrate 13.
  • a liquid crystal layer 15 is sealed between the TFT substrate 13 and the counter substrate 14 by a seal member 16.
  • the liquid crystal display panel 11 has a display area (not shown) and a frame-like non-display area (not shown) provided around the display area.
  • a plurality of pixels 18 provided in a matrix are formed in the display area.
  • the TFT substrate 13 is composed of an active matrix substrate.
  • the TFT substrate 13 has a glass substrate (not shown) as a transparent substrate.
  • a plurality of source lines 23 extending in parallel to each other and a plurality of gate lines 22 extending so as to intersect the source lines 23 are formed on the glass substrate.
  • the plurality of gate lines 22 and the plurality of source lines 23 are formed in a lattice shape as a whole, and the pixels 18 are formed in regions surrounded by the gate lines 22 and the source lines 23 in a rectangular shape.
  • Each of the gate wiring 22 and the source wiring 23 is configured by a single-layer film made of one type or a multi-layer film made of a plurality of types, for example, among Al, Cu, Mo, Ti, and the like.
  • Each pixel 18 is provided with a TFT 20 in the vicinity of the intersection of the gate wiring 22 and the source wiring 23.
  • the gate wiring 22 and the source wiring 23 are connected to the TFT 20.
  • the TFT 20 in the third embodiment is a bottom gate type TFT, and a gate electrode 26 branched from the gate wiring 22 and a semiconductor layer (not shown) facing the gate electrode 26 via a gate insulating film (not shown).
  • the gate electrode 26 and the gate wiring 22 are formed on a glass substrate and covered with the gate insulating film.
  • the gate insulating film is composed of, for example, a single-layer film made of one of SiNx (silicon nitride) and SiO 2 or a multi-layer film made of a plurality of kinds.
  • the semiconductor layer is formed in a rectangular island shape, for example.
  • the semiconductor layer is formed of a semiconductor such as a-Si, for example.
  • a part of the source electrode 25 and a part of the drain electrode 29 are overlapped with the semiconductor layer and the gate electrode 26, respectively.
  • the source electrode 25, the drain electrode 29, and the like are covered with an interlayer insulating film (not shown).
  • the interlayer insulating film is made of, for example, SiNx.
  • the plurality of pixels 18 are formed with pixel electrodes 30 connected to the drain electrodes 29 of the TFTs 20 provided in the pixels 18.
  • the pixel electrode 30 is formed on the surface of the interlayer insulating film, and is formed of a transparent conductive film such as ITO.
  • a common electrode (not shown) provided in common with the plurality of pixel electrodes 30 is formed on the counter substrate 14. Similar to the pixel electrode 30, the common electrode is also formed of a transparent conductive film such as ITO. Thus, the orientation of the liquid crystal layer 15 is controlled for each pixel 18 by controlling the potential difference between the common electrode having a predetermined potential and the pixel electrode 30 of each pixel 18.
  • the TFT 20 in this embodiment includes a first TFT 20 a in which the source electrode 25 is larger than the drain electrode 29 and a second TFT 20 b in which the drain electrode 29 is larger than the source electrode 25.
  • the source electrode 25 and the drain electrode 29 of the first TFT 20a each have a rectangular portion, and are arranged so that one sides thereof face each other.
  • the source electrode 25 of the first TFT 20 a is larger than the drain electrode 29.
  • one end of the source electrode 25 of the first TFT 20a overlaps the gate electrode. Further, one end portion of the drain electrode 29 of the first TFT 20 a also overlaps the gate electrode 26.
  • the overlapping width A between the source electrode 25 and the gate electrode 26 in the first TFT 20 a is wider than the overlapping width B between the drain electrode 29 and the gate electrode 26.
  • the source electrode 25 and the drain electrode 29 of the second TFT 20b each have a rectangular portion, and are arranged so that the sides thereof face each other.
  • the source electrode 25 of the second TFT 20 b is smaller than the drain electrode 29.
  • one end portion of the source electrode 25 overlaps the gate electrode 26, and one end portion of the drain electrode 29 overlaps the gate electrode 26.
  • the overlap width A between the source electrode 25 and the gate electrode 26 in the second TFT 20 b is narrower than the overlap width B between the drain electrode 29 and the gate electrode 26.
  • ⁇ Pixel arrangement configuration> As shown in FIG. 17, a plurality of first pixels 18 a in which first TFTs 20 a are formed and a plurality of pixels in which second TFTs 20 b are formed are arranged in a pixel column 19 including a plurality of pixels 18 arranged along the gate wiring 22. The second pixel 18b is included.
  • each pixel column 19 one first pixel 18 a and one second pixel 18 b are alternately arranged along the gate wiring 22.
  • a plurality of first pixels 18a or a plurality of second pixels 18b are arranged side by side.
  • first pixel 18 a and the second pixel 18 b for example, in each pixel column 19, two first pixels 18 a and two second pixels 18 b are alternately arranged along the gate wiring 22. May be arranged. That is, at least one first pixel 18 a and the same number of second pixels 18 b as the at least one first pixel 18 a are alternately arranged along the gate wiring 22 in the pixel column 19. Also good.
  • the liquid crystal display device 1 further includes an AC drive control unit 40 that applies signal voltages having the same polarity to the plurality of source lines 23 during a period of scanning one gate line 22.
  • the AC drive control unit 40 is configured to invert the polarity of the signal voltage applied to the plurality of source lines 23 for each period of scanning one gate line 22. That is, the driving method of the liquid crystal display device 1 is a 1H line inversion driving method in which the polarity of the signal voltage is inverted every 1H period.
  • the AC drive control unit 40 may be configured to invert the polarity of the signal voltage every time the plurality of gate wirings 22 are scanned. That is, the AC drive control unit 40 may be configured to perform nH line inversion driving. Therefore, the AC drive control unit 40 can be configured to apply signal voltages having the same polarity to the plurality of source lines 23 in each of the periods in which at least one gate line 22 is scanned.
  • the liquid crystal display device 1 is a liquid crystal display panel in which a TFT substrate 13 manufactured by forming a plurality of TFTs 20 and the like and a counter substrate 14 formed with a common electrode and the like are bonded together via a liquid crystal layer 15 and a seal member 16. 11 and the backlight unit 12 is disposed opposite to the liquid crystal display panel 11. Further, the electronic apparatus 10 is manufactured by incorporating the liquid crystal display device 1 into the housing 2 together with other functional circuits and the like.
  • a flicker pattern is displayed on the screen for the purpose of suppressing flickering on the liquid crystal display panel 11 with the backlight unit 12 facing each other, and the signal voltage and the common electrode voltage are initially adjusted. Voltage adjusting step is included.
  • the magnitude of the common electrode voltage is adjusted so that the flicker on the display screen is minimized while the flicker pattern 42 is displayed on the display screen of the liquid crystal display device 1.
  • FIG. 19 is a plan view showing 1H line inversion driving of the liquid crystal display device 1 according to the third embodiment.
  • the signal voltage applied to the source line 23 is set to + polarity in the 1H period during which the pixel column 19 a for halftone display of a certain n ⁇ 1 frame is scanned. To do.
  • the signal voltage applied to the source line 23 is inverted to have a negative polarity.
  • the arrow of each pixel 18 in FIG. 19 indicates the direction in which the off-leakage current flows.
  • the off-leak current is relatively small in the pixel column 19a displaying the halftone display that is visually recognized (S), and the off-leak current is relatively large in the second pixel 18b (L). Therefore, the same number of pixels with half-tone display on the entire screen includes the first pixel 18a having a relatively small off-leakage current (S) and the second pixel 18b having a relatively large off-leakage current (L).
  • the off-leak current of the first pixel 18a becomes relatively large (L), and the off-leak current of the second pixel 18b. Becomes relatively small (S). Therefore, the same number of pixels with half-tone display on the entire screen includes the first pixels 18a having a relatively large off-leakage current (L) and the second pixels 18b having a relatively small off-leakage current (S).
  • FIG. 20 is a plan view showing 1H line inversion driving of a liquid crystal display device as a comparative example.
  • all the pixels 118 have the same configuration, and each source electrode 125 is formed larger than the drain electrode 129.
  • the signal voltage applied to the source line 123 is set to + polarity in the 1H period in which the pixel column 119a for halftone display of a certain n ⁇ 1 frame is scanned. And In the 1H period during which the next pixel column 119b for black display is scanned, the signal voltage applied to the source wiring 123 is inverted to have a negative polarity.
  • the arrow of each pixel 118 in FIG. 20 indicates the direction in which the off-leakage current flows.
  • the off-leak current of each pixel 118 is relatively small (S). Accordingly, the entire screen is displayed in halftone by the (S) pixel 118 having a relatively small off-leakage current.
  • the off-leak current of each pixel 118 is relatively large (L). Therefore, the entire screen is displayed in halftone by the (L) pixel 118 having a relatively large off-leakage current.
  • the off-leak current of all the pixels 118 that perform halftone display is relatively small (S) before and after the frame changes, and the off-leakage of all the pixels 118 that perform halftone display. Since the state where the current is relatively large (L) is alternately switched, the flicker is likely to be visually recognized.
  • the present invention is not limited to the first to third embodiments, and the present invention includes a configuration in which these first to third embodiments are appropriately combined.
  • the present invention is useful for a liquid crystal display device and an electronic apparatus including the same.
  • Liquid crystal display device 10 Electronic equipment 18 pixels 18a first pixel 18b second pixel 19 pixel array 20 TFT 20a 1st TFT 20b 2nd TFT 22 Gate wiring 23 Source wiring 25 Source electrode 29 Drain electrode 30 pixel electrode 32 electrode limbs 36 electrode limbs 40 AC drive controller 51 First electrode 52 Second electrode

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Abstract

L'invention porte sur un dispositif d'affichage à cristaux liquides qui comporte une unité de commande d'attaque de courant alternatif qui inverse, par chaque période où une ligne de câblage de grille est balayée, une polarité d'une tension de signal à appliquer à une pluralité de lignes de câblage de source. Les transistors en couches minces comprennent un premier transistor en couches minces, dans lequel une largeur avec laquelle une électrode de source et une électrode de grille se chevauchent l'une l'autre est supérieure à une largeur avec laquelle l'électrode de drain et l'électrode de grille se chevauchent l'une l'autre, et un second transistor en couches minces, dans lequel une largeur avec laquelle l'électrode de source et l'électrode de grille se chevauchent l'une l'autre est inférieure à une largeur avec laquelle l'électrode de drain et l'électrode de grille se chevauchent l'une l'autre. Une colonne de pixels composée d'une pluralité de pixels alignés le long de la ligne de câblage de grille comprend une pluralité de premiers pixels, dont chacun a un premier transistor en couches minces formé dans celui-ci, et une pluralité de seconds pixels, dont chacun a un second transistor en couches minces formé dans celui-ci.
PCT/JP2012/001700 2011-03-16 2012-03-12 Dispositif d'affichage à cristaux liquides et appareil électronique WO2012124309A1 (fr)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003315766A (ja) * 2001-09-18 2003-11-06 Sharp Corp 液晶表示装置
JP2008009375A (ja) * 2006-05-31 2008-01-17 Hitachi Displays Ltd 表示装置
JP2008026908A (ja) * 2006-07-24 2008-02-07 Samsung Electronics Co Ltd 液晶表示装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003315766A (ja) * 2001-09-18 2003-11-06 Sharp Corp 液晶表示装置
JP2008009375A (ja) * 2006-05-31 2008-01-17 Hitachi Displays Ltd 表示装置
JP2008026908A (ja) * 2006-07-24 2008-02-07 Samsung Electronics Co Ltd 液晶表示装置

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