Hereinafter, the present invention is explained in detail in conjunction with an embodiment by reference to drawings.
Here, in all drawings for explaining the embodiment, parts having identical functions are given same symbols and their repeated explanation is omitted.
The liquid crystal display device to which the present invention is applied includes, for example, as shown in
The liquid crystal display panel 1 is a display panel which seals a liquid crystal material between a pair of substrates, wherein on one substrate out of the pair of substrates, as shown in
Further, in the liquid crystal display panel which corresponds to a color display used in a liquid crystal television receiver set and the like, one pixel shown in
Further, in the liquid crystal display panel of this embodiment, the video signal lines DL (DL1, DL2, DL3, . . . ) are configured such that one video signal line DL is arranged for each pair of pixels, wherein each pair is constituted of two neighboring pixels arranged in the extending direction (x direction) of the scanning signal line GL. Here, drains of the TFTs of two pixels which are arranged close to each other with one video signal line DL (for example, DL1,) sandwiched therebetween are connected to the same video signal line DL1.
Further, in the liquid crystal display panel of this embodiment, assuming a row consisting of a plurality of pixels which is arranged in the extending direction (x direction) of the scanning signal lines GL as a pixel row, two scanning signal lines GL are arranged to sandwich the pixel electrodes PX of the respective pixels of one pixel row. Further, between the pixel electrodes PX of two pixels arranged close to each other in the extending direction (y direction) of the video signal lines DL, two scanning signal lines GL are arranged. Here, in the pixel row which arranges the pixel electrodes PX between two neighboring scanning signal lines GL (for example, between GLn and GLn+1), the pixel which has a gate of the TFT thereof connected to one scanning signal line GLn+1 and the pixel which has a gate of the TFT thereof connected to another scanning signal line GLn are alternately arranged.
Further, with respect to one pair of pixels which is constituted of two pixels arranged close to each other with one video signal line DL (for example, DL1) sandwiched therebetween, when viewed along the extending direction of the video signal line DL1, a position (a direction) of the pixel having the TFT which is connected to the scanning signal line GL close to an input terminal of the video signal line DL1 and a position (a direction) of the pixel having the TFT which is connected to the scanning signal line GL remote from the input terminal are inverted for every pair of two pixels.
By allowing the liquid crystal display panel of this embodiment to have the circuit constitution shown in
In displaying video data amounting to 1 frame period in the liquid crystal display panel of this embodiment, for example, as shown in
Here, a common voltage Vcom inputted to the common electrodes is inputted with a potential thereof alternately changed over between a first potential and a second potential lower than the first potential in synchronism with timing that the scanning signal line GL which turns on the scanning signal is changed over. The changeover of the potential of the common voltage Vcom is performed by the common voltage control circuit 4, wherein the potential is changed over in synchronism with a clock signal used by the scanning driver 3.
Further, a video signal line DATA1 inputted to the video signal line DL (for example, DL1) forms a gradation voltage having a potential equal to or higher than the first potential during a period in which the common voltage Vcom is inputted with the first potential, and forms a gradation voltage of a potential equal to or lower than the second potential during a period in which the common voltage Vcom is inputted with the second potential. The formation of the gradation voltage is performed by the data driver 2, wherein the gradation voltage is formed in synchronism with the clock signal used in the scanning driver 3 and the changeover timing of the potential in the common voltage control circuit 4.
Due to such an operation, to the pixel electrode PX of the pixel which has a gate of the TFT thereof connected to the scanning signal line GL (for example, GLn) on which the scanning signal is turned on during the period in which the common voltage Vcom is inputted with the first potential, the gradation voltage having a potential equal to or higher than the potential of the common voltage Vcom, that is, the gradation voltage of positive polarity is written. Further, to the pixel electrode PX of the pixel which has a gate of the TFT thereof connected to the scanning signal line GL (for example, GLn+1) on which the scanning signal is turned on during the period in which the common voltage Vcom is inputted with the second potential, the gradation voltage having a potential equal to or lower than the potential of the common voltage Vcom, that is, the gradation voltage of negative polarity is written.
Although the video signal DATA1 inputted to one video signal line DL1 only is shown in
When the gradation voltage amounting to 1 frame period is written in the pixel electrodes of the respective pixels in this manner, the polarity of the respective pixel electrodes PX become as shown in
In this manner, by allowing the liquid crystal display panel of this embodiment to perform common inversion driving for every pixel row unit as shown in
Further, in the liquid crystal display panel of this embodiment, in forming the video signal (gradation voltage) inputted to the respective video signal lines DL in the data driver 2, the inversion relationship of positive polarity and negative polarity in the respective video signal lines DL is equal. That is, the polarities of the gradation voltages written in the pixel electrodes of the respective pixels connected to one scanning signal line are the same. Accordingly, compared to the conventional liquid crystal display device which adopts the double-scanning line method, the number of times that the polarity of the video signal is inverted by the data driver 2 can be drastically decreased thus lowering the power consumption and a heat value of the data driver 2. Further, by allowing the liquid crystal display panel of this embodiment to perform the common inversion driving, for example, compared to the driving method explained in conjunction with
The liquid crystal display panel 1 of this embodiment is, for example, as shown in
Further, when the liquid crystal display panel 1 is of a transmissive type or a transflective type, on surfaces of the TFT substrate 101 and the counter substrate 102 which are directed to the outside of the TFT substrate 101 and the counter substrate 102, a pair of polarizers 105A, 105B is arranged. Here, although not shown in
When the liquid crystal display panel 1 is of a reflective type, for example, the polarizer 105A, the retardation plate and the like which are arranged on a TFT-substrate-101 side are usually unnecessary.
In the display region DA of the liquid crystal display panel 1 having such a constitution, for example, the video signal lines DL, the scanning signal lines GL, the TFTs, the pixel electrodes PX and the like are formed to provide the constitution equivalent to the circuit constitution shown in
In the lateral-electric-field driving method, with respect to the TFT substrate 101, as shown in
Further, on the scanning signal lines GL and the counter electrodes CT, semiconductor layers SC, video signal lines DL (drain electrodes SD1) and the source electrodes SD2 are formed by way of a first insulation layer PAS1. The semiconductor layers SC are formed by etching an amorphous silicon (a-Si) film and, thereafter, by implanting impurities into drain regions and source regions, for example. The video signal lines DL and the source electrodes SD2 are formed by etching a conductive film made of aluminum or the like, for example. Further, the drain electrodes SD1 are formed by branching portions of the video signal lines DL. Here, the branching direction is determined to be equivalent to the circuit shown in
Further, on the video signal lines DL or the like, the pixel electrodes PX are formed by way of a second insulation layer PAS2. The pixel electrodes PX are formed by etching a conductive film having high optical transmissivity made of ITO or the like, for example, and are connected with the source electrodes SD2 via through holes TH. Further, the pixel electrodes PX are formed in a comb-teeth shape having a plurality of slits SL on regions where the slits SL overlap the counter electrodes CT in a plan view. Here, it is needless to say that the number, the direction or the like of the slits SL can be properly changed.
Further, an orientation film ORI1 is formed on the pixel electrodes PX.
On the other hand, with respect to the counter substrate 102, on a surface of the insulation substrate SUB2 formed of a glass substrate or the like, a light blocking film BM which is referred to as a black matrix and color filters CF are formed. The light blocking film BM is formed in a grid pattern to separate the respective pixels by etching a conductive film or an insulation film having optical transmissivity of approximately 0, for example. The color filters CF are formed by etching an insulation film or exposing and developing an insulation film, for example. Further, the color filters CF are formed such that in opening regions of the light blocking film BM, a filter serving for a display of R (red), a filter serving for a display of G (green) and a filter serving for a display of B (blue) are arranged periodically.
Further, on the light blocking film BM and the color filters CF, an orientation film ORI2 is formed by way of an overcoat layer OC, for example.
In this manner, in the liquid crystal display panel 1 which adopts a lateral electric field driving method, by providing the structure equivalent to the circuit constitution shown in
Here, in this embodiment, as the constitutional example of the liquid crystal display panel 1 which adopts a lateral electric field driving method, the constitution shown in
The liquid crystal display panel 1 of this embodiment is not limited to the liquid crystal display panel which adopts the lateral electric field driving method in which the pixels within the display region DA have the constitution shown in
When the liquid crystal display panel 1 adopts the vertical electric field driving method, with respect to the TFT substrate 101, for example, as shown in
Further, on the scanning signal lines GL, semiconductor layers SC, video signal lines DL (drain electrodes SD1) and the source electrodes SD2 are formed by way of a first insulation layer PAS1. Also in this case, the drain electrodes SD1 are formed by branching portions of the video signal lines DL, and the branching direction is determined to be equivalent to the circuit shown in
Further, on the video signal lines DL, pixel electrodes PX are formed by way of a second insulation layer PAS2. The pixel electrodes PX are connected with source electrodes SD2 via through holes TH. Further, in the liquid crystal display panel 1 which adopts the vertical electric field driving method, it is unnecessary to form slits SL in the pixel electrodes PX. Here, the pixel electrode PX is formed such that a portion of the pixel electrode PX overlaps in a plan view, the scanning signal line on a side opposite to the scanning signal line to which a gate of the TFT which is connected via a through hole TH is connected, and a holding capacitance is formed by the scanning signal line, the pixel electrode PX and insulation layers PAS1, PAS2 interposed between the scanning signal line and the pixel electrode PX.
Further, an orientation film ORI1 is formed on the pixel electrodes PX.
On the other hand, with respect to the counter substrate 102, on a surface of the insulation substrate SUB2 formed of a glass substrate or the like, a light blocking film BM which is referred to as a black matrix and color filters CF are formed. The light blocking film BM is formed in a grid pattern to separate the respective pixels by etching a conductive film or an insulation film having optical transmissivity of approximately 0, for example. The color filters CF are formed by etching an insulation film or exposing and developing an insulation film, for example. Further, the color filters CF are formed such that in opening regions of the light blocking film BM, a filter serving for a display of R (red), a filter serving for a display of G (green) and a filter serving for a display of B (blue) are arranged periodically.
Further, on the light blocking film BM and the color filters CF, the counter electrode CT is formed by way of an overcoat layer OC, for example. Further, the orientation film ORI2 is formed on the counter electrode CT.
In this manner, in the liquid crystal display panel 1 which adopts a vertical electric field driving method, by providing the structure equivalent to the circuit constitution shown in
When the liquid crystal display panel 1 of this embodiment adopts the vertical electric field driving method, for example, in place of forming the holding capacitance attributed to the scanning signal line, the pixel electrodes PX and the first insulation layer PAS1 interposed between the scanning signal line and the pixel electrode PX as shown in
In case of the liquid crystal display panel 1 which adopts the vertical electric field driving method having the holding capacitance lines, with respect to the TFT substrate 101, for example, as shown in
Further, on the scanning signal lines GL and the holding capacitance lines StgL, semiconductor layers SC, video signal lines DL (drain electrodes SD1) and the source electrodes SD2 are formed by way of a first insulation layer PAS1. Also in this case, the drain electrodes SD1 are formed by branching portions of the video signal lines DL. Here, the branching direction is determined equivalent to the circuit shown in
Further, on the video signal lines DL or the like, the pixel electrodes PX are formed by way of a second insulation layer PAS2. The pixel electrodes PX are connected with source electrodes SD2 via through holes TH. Here, the pixel electrode PX has a portion which overlaps the holding capacitance line StgL in a plan view, and holding capacitance Cstg is formed by the pixel electrode PX, the holding capacitance line StgL and insulation layers PAS1, PAS2 which are interposed between the pixel electrode PX and the holding capacitance line StgL. Here, by changing a width of the holding capacitance line StgL or a shape of a portion of the holding capacitance line StgL which overlaps the pixel electrode PX in a plan view, a magnitude of the holding capacitance can be easily changed.
Further, an orientation film ORI1 is formed on the pixel electrodes PX.
On the other hand, with respect to the counter substrate 102, on a surface of the insulation substrate SUB2 formed of a glass substrate or the like, a light blocking film BM which is referred to as a black matrix and color filters CF are formed. The light blocking film BM is formed in a grid pattern to separate the respective pixels by etching a conductive film or an insulation film having optical transmissivity of approximately 0, for example. The color filters CF are formed by etching an insulation film or exposing and developing an insulation film, for example. Further, the color filters CF are formed such that in opening regions of the light blocking film BM, a filter serving for a display of R (red), a filter serving for a display of G (green) and a filter serving for a display of B (blue) are arranged periodically.
Further, on the light blocking film BM and the color filters CF, the counter electrode CT is formed by way of an overcoat layer OC, for example. Further, the orientation film ORI2 is formed on the counter electrode CT.
In this manner, in the liquid crystal display panel 1 which adopts a vertical electric field driving method, by providing the structure equivalent to the circuit constitution shown in
Here, in this embodiment, as the constitutional example of the liquid crystal display panel 1 which adopts the vertical electric field driving method, the constitution shown in
Although the present invention has been specifically explained in conjunction with the embodiment heretofore, it is needless to say that the present invention is not limited to the above-mentioned embodiment and various modifications are conceivable without departing from the gist of the present invention.
Number | Date | Country | Kind |
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2006-250989 | Sep 2006 | JP | national |