The present invention relates to a display device having a plurality of data signal lines provided for each column of pixels.
In recent years, liquid crystal display apparatuses have been made larger and larger in size and higher and higher in definition. Accordingly, there have been increases in the number of pixels and increases in wiring resistance and the like of data signal lines. This has made it difficult to sufficiently charge each pixel.
It should be noted here that Patent Literature 1 (see
The inventors of the present application found that such provision of each column of pixels with a plurality of data signal lines generates display unevenness a possible cause of which is a parasitic capacitance between a pixel electrode contained in the column of pixels and a data signal line corresponding to the pixel electrode. The reason for the generation of such display unevenness is explained below with reference to
A parasitic capacitance produced in each pixel is explained here.
According to the present driving method, as shown in
Specifically, in F1, of the consecutive frames F1 and F2, the data signal line 15p, the data signal line 15Q, and the data signal line 15r are each supplied with a data signal of a positive polarity during the kth horizontal scanning period (including the scanning period for the scanning signal lines 16a and 16b), supplied with a data signal of a positive polarity during the (k+1)th horizontal scanning period (including the scanning period for the scanning signal lines 16c and 16d), and also supplied with a data signal of a positive polarity during the (k+2)th horizontal scanning period (including the scanning period for the scanning signal lines 16e and 16f). Meanwhile, the data signal line 15P, the data signal line 15q, and the data signal line 15R are each supplied with a data signal of a negative polarity during the kth horizontal scanning period (including the scanning period for the scanning signal lines 16a and 16b), supplied with a data signal of a negative polarity during the (k+1)th horizontal scanning period (including the scanning period for the scanning signal lines 16c and 16d), and also supplied with a data signal of a negative polarity during the (k+2)th horizontal scanning period (including the scanning period for the scanning signal lines 16e and 16f).
On the other hand, in F2, the data signal line 15p, the data signal line 15Q, and the data signal line 15r are each supplied with a data signal of a negative polarity during the kth horizontal scanning period (including the scanning period for the scanning signal lines 16a and 16b), supplied with a data signal of a negative polarity during the (k+1)th horizontal scanning period (including the scanning period for the scanning signal lines 16c and 16d), and also supplied with a data signal of a negative polarity during the (k+2)th horizontal scanning period (including the scanning period for the scanning signal lines 16e and 16f). Meanwhile, the data signal line 15P, the data signal line 15q, and the data signal line 15R are each supplied with a data signal of a positive polarity during the kth horizontal scanning period (including the scanning period for the scanning signal lines 16a and 16b), supplied with a data signal of a positive polarity during the (k+1)th horizontal scanning period (including the scanning period for the scanning signal lines 16c and 16d), and also supplied with a data signal of a positive polarity during the (k+2)th horizontal scanning period (including the scanning period for the scanning signal lines 16e and 16f).
It should be noted here that the image of
Thus, the data signal line 15q is supplied with a data signal of a negative polarity corresponding to gray during the kth horizontal scanning period, is supplied with a data signal of a negative polarity corresponding to white during the (k+1)th horizontal scanning period, and is supplied with a data signal of a negative polarity corresponding to gray during the (k+2)th horizontal scanning period. Meanwhile, the data signal line 15Q is supplied with a data signal of a positive polarity corresponding to gray during the kth horizontal scanning period, is supplied with a data signal of a positive polarity corresponding to black during the (k+1)th horizontal scanning period, and is supplied with a data signal of a positive polarity corresponding to gray during the (k+2)th horizontal scanning period. That is, at the transition from the kth horizontal scanning period to the (k+1)th horizontal scanning period, the potentials of the data signals that are supplied to the data signal lines 15q and 15Q change in a falling direction (negative direction), and at the transition from the (k+1)th horizontal scanning period to the (k+2)th horizontal scanning period, the potentials of the data signals that are supplied to the data signal lines 15q and 15Q change in a rising direction (positive direction).
For this reason, in the pixel electrode 17a, for example, the pixel potential Va (data signal of a negative polarity corresponding to gray) written during the kth horizontal scanning period changes in a falling direction (negative direction) in the (k+1)th horizontal scanning period due to the parasitic capacitances Csd_aq and Csd_aQ between the pixel electrode 17a and the data signal lines 15q and 15Q, respectively, and changes in a rising direction (positive direction) in the (k+2)th horizontal scanning period due to the parasitic capacitances Csd_aq and Csd_aQ between the pixel electrode 17a and the data signal lines 15q and 15Q, respectively (see
Meanwhile, in the pixel electrode 17e, the pixel potential Ve (data signal of a positive polarity corresponding to gray) written during the previous frame period changes in a falling direction (negative direction) in the (k+1)th horizontal scanning period due to the parasitic capacitances Csd_eq and Csd_eQ (not illustrated) between the pixel electrode 17e and the data signal lines 15q and 15Q, respectively (see
For this reason, as shown in
In view of the foregoing problems, the present invention has as an object to enhance the display quality of a display device having a plurality of data signal lines provided for each column of pixels.
In order to solve the foregoing problems, a display device according to the present invention is a display device including: a plurality of scanning signal lines; and a plurality of data signal lines, two of which are provided for each column of pixels containing a plurality of pixels arranged in a column-wise direction in which the data signal lines extend, in each column of pixels, a pixel electrode contained in either of two pixels adjacent to each other in the column-wise direction and a pixel electrode contained in the other one of the two pixels adjacent to each other being connected to different data signal lines via transistors, respectively, for a first, a second, and a third columns of pixels arranged in sequence, each pixel electrode contained in the second column of pixels forming a capacitance with either of the two data signal lines provided for the first column of pixels and forming a capacitance with either of the two data signal lines provided for the third column of pixels.
According to the foregoing configuration, the influence of a crosstalk due to parasitic capacitances formed between each pixel electrode and data signal lines corresponding to the pixel, respectively, can be curbed by capacitances formed between that pixel electrode and data signal lines corresponding to both adjacent columns of pixels, respectively. This makes it possible to suppress a change in pixel potential in each pixel electrode and thus enhance the display quality of the liquid crystal display apparatus.
As described above, a liquid crystal device according to the present invention is configured such that for a first, a second, and a third columns of pixels arranged in sequence, each pixel electrode contained in the second column of pixels forms a capacitance with either of the two data signal lines provided for the first column of pixels and forms a capacitance with either of the two data signal lines provided for the third column of pixels. This makes it possible to enhance the display quality of a display device having a plurality of data signal lines provided for each column of pixels.
Examples of embodiments according to the present invention are described below with reference to the drawings. For convenience of explanation, the following description assumes that the term “column-wise direction” means the direction in which the data signal lines extend and the term “row-wise direction” means the direction in which the scanning signal lines extend. Note, however, that depending on how the present liquid crystal display apparatus (or the liquid crystal panel and the active-matrix substrate that are used in the present liquid crystal display apparatus) is used (viewed), the scanning signal lines may extend in a transverse direction or in a longitudinal direction. Note, also, that each pixel region of the active-matrix substrate corresponds to a single pixel of the liquid crystal panel.
Further, the present liquid crystal panel 10 has a pixel 111 provided at intersections between the data signal lines 15r and 15R and the scanning signal line 16a, a pixel 112 provided at intersections between the data signal lines 15r and 15R and the scanning signal line 16b, and a pixel 113 provided at intersections between the data signal lines 15r and 15R and the scanning signal line 16c. The present liquid crystal panel 10 also has pixels 114, 115, and 116 provided in similar manners.
The present liquid crystal panel 10 has a retention capacitor wire 18a provided for the pixels 101 and 111, a retention capacitor wire 18b provided for the pixels 102 and 112, a retention capacitor wire 18c provided for the pixels 103 and 113, a retention capacitor wire 18d provided for the pixels 104 and 114, a retention capacitor wire 18e provided for the pixels 105 and 115, and a retention capacitor wire 18f provided for the pixels 106 and 116.
It should be noted here that the data signal lines 15p and 15P correspond to a column of pixels α (first column of pixels) containing a plurality of pixels arranged in the column-wise direction, that the data signal lines 15q and 15Q correspond to a column of pixels β (second column of pixels) containing the pixels 101 to 106, and that the data signal lines 15r and 15R correspond to a column of pixels γ (third column of pixels) containing the pixels 111 to 116.
Furthermore, each pixel is provided with a pixel electrode. The pixel 101 has its pixel electrode 17a connected to the data signal line 15q via a transistor 12a connected to the scanning signal line 16a. The pixel 102 has its pixel electrode 17b connected to the data signal line 15Q via a transistor 12b connected to the scanning signal line 16b. The pixel 103 has its pixel electrode 17c connected to the data signal line 15q via a transistor 12c connected to the scanning signal line 16c. The pixel 104 has its pixel electrode 17d connected to the data signal line 15Q via a transistor 12d connected to the scanning signal line 16d. The pixel 105 has its pixel electrode 17e connected to the data signal line 15q via a transistor 12e connected to the scanning signal line 16e. The pixel 106 has its pixel electrode 17f connected to the data signal line 15Q via a transistor 12f connected to the scanning signal line 16f.
Meanwhile, the pixel 111 has its pixel electrode 17A connected to the data signal line 15r via a transistor 12A connected to the scanning signal line 16a. The pixel 112 has its pixel electrode 17B connected to the data signal line 15R via a transistor 12B connected to the scanning signal line 16b. The pixel 113 has its pixel electrode 17C connected to the data signal line 15r via a transistor 12C connected to the scanning signal line 16c. The pixel 114 has its pixel electrode 17D connected to the data signal line 15R via a transistor 12D connected to the scanning signal line 16d. The pixel 115 has its pixel electrode 17E connected to the data signal line 15r via a transistor 12E connected to the scanning signal line 16e. The pixel 116 has its pixel electrode 17F connected to the data signal line 15R via a transistor 12F connected to the scanning signal line 16f.
That is, the data signal line 15Q, connected to the respective pixel electrodes (17b, 17d, 17f) of the even-numbered pixels (102, 104, 106) of the column of pixels β, and the data signal line 15r, connected to the respective pixel electrodes (17a, 17c, 17e) of the odd-numbered pixels (111, 113, 115) of the column of pixels γ, are adjacent to each other.
Further, the scanning signal line 16a, which corresponds to the pixel electrode 17a of the pixel 101 and the pixel electrode 17A of the pixel 111, and the scanning signal line 16b, which corresponds to the pixel electrode 17b of the pixel 102 and the pixel electrode 17B of the pixel 112, are electrically connected to each other inside or outside of the panel, so that the scanning signal lines 16a and 16b are simultaneously selected. Further, the scanning signal line 16c, which corresponds to the pixel electrode 17c of the pixel 103 and the pixel electrode 17C of the pixel 113, and the scanning signal line 16d, which corresponds to the pixel electrode 17d of the pixel 104 and the pixel electrode 17D of the pixel 114, are electrically connected to each other inside or outside of the panel, so that the scanning signal lines 16c and 16d are simultaneously selected. Further, the scanning signal line 16e, which corresponds to the pixel electrode 17e of the pixel 105 and the pixel electrode 17E of the pixel 115, and the scanning signal line 16f, which corresponds to the pixel electrode 17f of the pixel 106 and the pixel electrode 17F of the pixel 116, are electrically connected to each other inside or outside of the panel, so that the scanning signal lines 16e and 16f are simultaneously selected. It should be noted that a configuration is possible in which each of the pairs of scanning signal lines, namely the scanning signal lines 16a and 16b, the scanning signal lines 16c and 16d, or the scanning signal lines 16e and 16f, are simultaneously selected without being electrically connected to each other inside or outside of the panel.
The liquid crystal panel 10 thus configured has a retention capacitance Cha formed between the retention capacitor wire 18a and the pixel electrode 17a, a retention capacitance Chb formed between the retention capacitor wire 18b and the pixel electrode 17b, a retention capacitance Chc formed between the retention capacitor wire 18c and the pixel electrode 17c, a retention capacitance Chd formed between the retention capacitor wire 18d and the pixel electrode 17d, a retention capacitance Che formed between the retention capacitor wire 18e and the pixel electrode 17e, and a retention capacitance Chf formed between the retention capacitor wire 18f and the pixel electrode 17f. Similarly, the liquid crystal panel 10 thus configured has a retention capacitance ChA formed between the retention capacitor wire 18a and the pixel electrode 17A, a retention capacitance ChB formed between the retention capacitor wire 18b and the pixel electrode 17B, a retention capacitance ChC formed between the retention capacitor wire 18c and the pixel electrode 17C, a retention capacitance ChD formed between the retention capacitor wire 18d and the pixel electrode 17D, a retention capacitance ChE formed between the retention capacitor wire 18e and the pixel electrode 17E, and a retention capacitance ChF formed between the retention capacitor wire 18f and the pixel electrode 17F.
As shown in
Due to such structural parasitic capacitances, there has conventionally been such a problem that changes in pixel potential after writing of data signals to the pixel electrodes cause display unevenness (see
In view of this problem, the present invention has a configuration in which such changes in pixel potential are suppressed by each pixel electrode's forming a capacitance with each of the data signal lines respectively corresponding to both adjacent columns of pixels.
Specifically,
Similarly, the pixel 111 has a capacitance CAQ formed between the pixel electrode 17A and the data signal line 15Q and a capacitance CAs formed between the pixel electrode 17A and the data signal line 15s. The pixel 112 has a capacitance CBQ formed between the pixel electrode 17B and the data signal line 15Q and a capacitance CBs formed between the pixel electrode 17B and the data signal line 15s. The pixel 113 has a capacitance CCQ formed between the pixel electrode 17C and the data signal line 15Q and a capacitance CCs formed between the pixel electrode 17C and the data signal line 15s. The pixel 114 has a capacitance CDQ formed between the pixel electrode 17d and the data signal line 15Q and a capacitance CDs formed between the pixel electrode 17D and the data signal line 15s. The pixel 115 has a capacitance CEQ formed between the pixel electrode 17E and the data signal line 15Q and a capacitance CEs formed between the pixel electrode 17E and the data signal line 15s. The pixel 116 has a capacitance CFQ formed between the pixel electrode 17F and the data signal line 15Q and a capacitance CFs formed between the pixel electrode 17F and the data signal line 15s.
(Method for Driving a Liquid Crystal Panel)
According to the present driving method, as shown in
Specifically, in F1, of the consecutive frames F1 and F2, the data signal line 15p, the data signal line 15Q, and the data signal line 15r are each supplied with a data signal of a positive polarity during the kth horizontal scanning period (including the scanning period for the scanning signal lines 16a and 16b), supplied with a data signal of a positive polarity during the (k+1)th horizontal scanning period (including the scanning period for the scanning signal lines 16c and 16d), and also supplied with a data signal of a positive polarity during the (k+2)th horizontal scanning period (including the scanning period for the scanning signal lines 16e and 16f). Meanwhile, the data signal line 15P, the data signal line 15q, and the data signal line 15R are each supplied with a data signal of a negative polarity during the kth horizontal scanning period (including the scanning period for the scanning signal lines 16a and 16b), supplied with a data signal of a negative polarity during the (k+1)th horizontal scanning period (including the scanning period for the scanning signal lines 16c and 16d), and also supplied with a data signal of a negative polarity during the (k+2)th horizontal scanning period (including the scanning period for the scanning signal lines 16e and 16f). Moreover, at the same time as the start of the kth horizontal scanning period, a pulse of the gate pulse signal (gate-on pulse signal) GPa and a pulse of the gate pulse signal GPb are raised. At the same time as the start of the (k+1)th horizontal scanning period (i.e., as the end of the kth horizontal scanning period), the pulses of GPa and GPb are dropped and a pulse of the gate pulse signal GPc and a pulse of the gate pulse signal GPd are raised. At the same time as the start of the (k+2)th horizontal scanning period (i.e., as the end of the (k+1)th horizontal scanning period), the pulses of GPc and GPd are dropped and a pulse of the gate pulse signal GPe and a pulse of the gate pulse signal GPf are raised.
Thus, as shown in the frame F1 of
On the other hand, in F2, the data signal line 15p, the data signal line 15Q, and the data signal line 15r are each supplied with a data signal of a negative polarity during the kth horizontal scanning period (including the scanning period for the scanning signal lines 16a and 16b), supplied with a data signal of a negative polarity during the (k+1)th horizontal scanning period (including the scanning period for the scanning signal lines 16c and 16d), and also supplied with a data signal of a negative polarity during the (k+2)th horizontal scanning period (including the scanning period for the scanning signal lines 16e and 16f). Meanwhile, the data signal line 15P, the data signal line 15q, and the data signal line 15R are each supplied with a data signal of a positive polarity during the kth horizontal scanning period (including the scanning period for the scanning signal lines 16a and 16b), supplied with a data signal of a positive polarity during the (k+1)th horizontal scanning period (including the scanning period for the scanning signal lines 16c and 16d), and also supplied with a data signal of a positive polarity during the (k+2)th horizontal scanning period (including the scanning period for the scanning signal lines 16e and 16f). Moreover, at the same time as the start of the kth horizontal scanning period, the pulse of the gate pulse signal (gate-on pulse signal) GPa and the pulse of the gate pulse signal GPb are raised. At the same time as the start of the (k+1)th horizontal scanning period (i.e., as the end of the kth horizontal scanning period), the pulses of GPa and GPb are dropped and a pulse of the gate pulse signal GPc and a pulse of the gate pulse signal GPd are raised. At the same time as the start of the (k+2)th horizontal scanning period (i.e., as the end of the (k+1)th horizontal scanning period), the pulses of GPc and GPd are dropped and a pulse of the gate pulse signal GPe and a pulse of the gate pulse signal GPf are raised.
Thus, as shown in the frame F2 of
The above driving method achieves dot-reversal driving.
It should be noted here that the image of
Thus, the data signal line 15q is supplied with a data signal of a negative polarity corresponding to gray during the kth horizontal scanning period, is supplied with a data signal of a negative polarity corresponding to white during the (k+1)th horizontal scanning period, and is supplied with a data signal of a negative polarity corresponding to gray during the (k+2)th horizontal scanning period. Meanwhile, the data signal line 15Q is supplied with a data signal of a positive polarity corresponding to gray during the kth horizontal scanning period, is supplied with a data signal of a positive polarity corresponding to black during the (k+1)th horizontal scanning period, and is supplied with a data signal of a positive polarity corresponding to gray during the (k+2)th horizontal scanning period. That is, at the transition from the kth horizontal scanning period to the (k+1)th horizontal scanning period, the potentials of the data signals that are supplied to the data signal lines 15q and 15Q change in a falling direction (negative direction), and at the transition from the (k+1)th horizontal scanning period to the (k+2)th horizontal scanning period, the potentials of the data signals that are supplied to the data signal lines 15q and 15Q change in a rising direction (positive direction).
For this reason, in the pixel electrode 17a, for example, the pixel potential Va (data signal of a negative polarity corresponding to gray) written during the kth horizontal scanning period changes in a falling direction (negative direction) in the (k+1)th horizontal scanning period due to the parasitic capacitances Csd_aq and Csd_aQ between the pixel electrode 17a and the data signal lines 15q and 15Q, respectively, and changes in a rising direction (positive direction) in the (k+2)th horizontal scanning period due to the parasitic capacitances Csd_aq and Csd_aQ between the pixel electrode 17a and the data signal lines 15q and 15Q, respectively (see
In the present configuration, however, the pixel electrode 17a forms capacitances CaP and Car with the data signal lines 15P and 15r, respectively. The data signal line 15P is supplied with a data signal of a negative polarity corresponding to gray during the kth horizontal scanning period, is supplied with a data signal of a negative polarity corresponding to black during the (k+1)th horizontal scanning period, and is supplied with a data signal of a negative polarity corresponding to gray during the (k+2)th horizontal scanning period. The data signal line 15r is supplied with a data signal of a positive polarity corresponding to gray during the kth horizontal scanning period, is supplied with a data signal of a positive polarity corresponding to white during the (k+1)th horizontal scanning period, and is supplied with a data signal of a positive polarity corresponding to gray during the (k+2)th horizontal scanning period.
For this reason, in the pixel electrode 17a, the pixel potential Va (data signal of a negative polarity corresponding to gray) written during the kth horizontal scanning period changes in a rising direction (positive direction) in the (k+1)th horizontal scanning period due to the capacitances CaP and Car, and changes in a falling direction (negative direction) in the (k+2)th horizontal scanning period due to the capacitances CaP and Car. Thus, the changes in potential due to the parasitic capacitances can be canceled by the changes in potential due to the capacitances formed between the pixel electrode and the data signal lines corresponding to both adjacent columns of pixels, respectively. This makes it possible to curb the influence of a crosstalk and thus enhance display quality.
Similarly, in the pixel electrode 17b, the pixel potential Vb (data signal of a positive polarity corresponding to gray) written during the kth horizontal scanning period changes in a falling direction (negative direction) due to the parasitic capacitances Csd_bq and Csd_bQ between the pixel electrode 17b and the data signal lines 15q and 15Q, respectively (see
(Example Configuration 1 of a Liquid Crystal Panel)
In Example Configuration 1, as shown in
The present liquid crystal panel 10 has a pixel electrode 17a provided so that part thereof overlaps the data signal lines 15P, 15q, 15Q, and 15r, a pixel electrode 17b provided so that part thereof overlaps the data signal lines 15P, 15q, 15Q, and 15r, a pixel electrode 17A provided so that part thereof overlaps the data signal lines 15Q, 15r, 15R, and 15s, and a pixel electrode 17B provided so that part thereof overlaps the data signal lines 15Q, 15r, 15R, and 15s.
Further, the present liquid crystal panel 10 has a retention capacitor wire 18a provided in such a way as to overlap the pixel electrodes 17a and 17A and a retention capacitor wire 18b provided in such a way as to overlap the pixel electrodes 17b and 17B.
Moreover, the scanning signal line 16a functions as the gate electrode of the transistor 12a, which has its source electrode connected to the data signal line 15q and which has its drain electrode connected to a capacitor electrode 37a via a drain drawing electrode 27a. The capacitor electrode 37a is provided above the retention capacitor wire 18a and is connected to the pixel electrode 17a via a contact hole 11a. Further, the scanning signal line 16b functions as the gate electrode of the transistor 12b, which has its source electrode connected to the data signal line 15Q and which has its drain electrode connected to a capacitor electrode 37b via a drain drawing electrode 27b. The capacitor electrode 37b is provided above the retention capacitor wire 18b and is connected to the pixel electrode 17b via a contact hole 11b.
Similarly, the scanning signal line 16a functions as the gate electrode of the transistor 12A, which has its source electrode connected to the data signal line 15r and which has its drain electrode connected to a capacitor electrode 37A via a drain drawing electrode 27A. The capacitor electrode 37A is provided above the retention capacitor wire 18A and is connected to the pixel electrode 17A via a contact hole 11A. Further, the scanning signal line 16b functions as the gate electrode of the transistor 12B, which has its source electrode connected to the data signal line 15R and which has its drain electrode connected to a capacitor electrode 37B via a drain drawing electrode 27B. The capacitor electrode 37B is provided above the retention capacitor wire 18b and is connected to the pixel electrode 17B via a contact hole 11B.
The present liquid crystal panel 10 is configured such that the retention capacitance Cha (see
Meanwhile, the color filter substrate 4 has a glass substrate 41 on which a black matrix 13 and a colored layer (color filter layer) 14 have been formed, with a common electrode (com) 28 formed on the black matrix 13 and the color filter layer 14 and covered with an alignment film 19.
The foregoing has described a configuration in which data signals are simultaneously written to pixel electrodes respectively contained in two pixels adjacent to each other in the column-wise direction. However, the present invention is not to be limited to such a configuration. A configuration may be such that writing to each pixel electrode is carried out by sequentially (one by one) selecting scanning signal lines corresponding to each separate pixel.
(Method for Fabricating a Liquid Crystal Panel)
Next, a method for fabricating a liquid crystal panel of the present invention is described. The method for fabricating a liquid crystal panel includes an active-matrix substrate fabricating step, a color filter substrate fabricating step, and an assembling step of joining the substrates on top of each other and filling a space between the substrates with liquid crystals.
First, a metal film made of titanium, chromium, aluminum, molybdenum, tantalum, tungsten, copper, or the like, an alloy film made of an alloy thereof, or a laminate film (1000 Å to 3000 Å thick) obtained by joining such films on top of each other is formed by sputtering on a substrate made of glass, plastic, or the like. After that, patterning is carried out by a photolithographic technique (photo engraving process, hereinafter referred to as “PEP technique”, which includes an etching step), so that scanning signal lines (gate electrode of each transistor) and retention capacitor wires are formed.
Next, an inorganic insulating film (approximately 3000 Å to 5000 Å thick) of silicon nitride, silicon oxide, or the like is formed by CVD (chemical vapor deposition) over the entire substrate on which the scanning signal lines have been formed, and the photoresist is removed, so that a gate insulating film is formed.
Then, an intrinsic amorphous silicon film (1000 Å to 3000 Å thick) and an n+ amorphous silicon film (approximately 400 Å to 700 Å thick) doped with phosphor are continuously formed by CVD over the gate insulating film (entire substrate). After that, patterning is carried out by the PEP technique, and the photoresist is removed, so that a silicon laminate constituted by the intrinsic amorphous silicon layer and the n+ amorphous silicon layer is formed in the form of an island on the gate electrode.
Then, a metal film made of titanium, chromium, aluminum, molybdenum, tantalum, tungsten, copper, or the like, an alloy film made of an alloy thereof, or a laminate film (1000 Å to 3000 Å thick) obtained by joining such films on top of each other is formed by sputtering over the entire substrate on which the silicon laminate has been formed. After that, patterning is carried out by the PEP technique, so that data signal lines, the source and drain electrodes of transistors, drain drawing electrodes, capacitor electrodes, and drawing wires are formed (formation of a metal layer). The resist is removed as needed here.
Furthermore, by using, as a mask, the photoresist used in formed the metal wires or the source and drain electrodes, the n+ amorphous silicon layer constituting the silicon laminate is etched away, and the photoresist is removed, so that channels in the transistors are formed. It should be noted here that the semiconductor layer may be formed by an amorphous silicon film as described above, but a polysilicon film may also be formed. Further, improvements in crystallinity can be made by performing a laser anneal process on the amorphous silicon film and the polysilicon film. This makes it possible to improve the characteristics of each transistor (TFT) with an increase in speed at which electrons move within the semiconductor layer.
Next, an interlayer insulating film is formed over the entire substrate on which the data signal lines and the like have been formed. Specifically, with use of a mixed gas of SiH4 gas and NH3 gas, an inorganic interlayer insulating film (passivation film) made of SiNx approximately 300 Å thick is formed by CVD in such a way as to cover the entire surface of the substrate, and furthermore, an organic interlayer insulting film made of a positive photosensitive acrylic resin approximately 3 μm thick is formed by spin coating or die coating.
After that, the organic interlayer insulating film is patterned with contact holes by the PEP techniques, and then sintered. Furthermore, by using the pattern on the organic interlayer insulating film, the inorganic interlayer insulating film or the inorganic interlayer insulating film and the gate insulating film is/are etched away, so that the contact holes are formed.
Then, a transparent conductive film (1000 Å to 2000 Å thick) made of ITO (indium tin oxide), IZO (indium zinc oxide), zinc oxide, tin oxide, or the like is formed by sputtering on the interlayer insulating film over the entire substrate in which the contact holes have been formed. After that, patterning is carried out by the PEP technique, and the resist is removed, so that each pixel electrode is formed.
Finally, a polyimide resin 500 Å to 1000 Å thick is printed on the pixel electrodes over the entire substrate. After that, the polyimide resin is calcined, and rubbed with rotating cloth in one direction, so that an alignment film is formed. This is how the active-matrix substrate is fabricated.
The following describes the color filter substrate fabricating step.
First, a black matrix is formed by forming a chromium thin film or a film of resin containing a black pigment on a substrate (entire substrate) made of glass, plastic, or the like and patterning the film by the PEP technique. Next, a red, green, and blue color filter layer (approximately 2 μm thick) is pattern-formed in spaces in the black matrix by using a pigment dispersion method.
Then, a common electrode (com) is formed by forming a transparent conductive film (approximately 1000 Å thick) made of ITO, IZO, zinc oxide, tin oxide, or the like on the color filter layer over the entire substrate.
Finally, a polyimide resin 500 Å to 1000 Å thick is printed on the common electrode over the entire substrate. After that, the polyimide resin is calcined, and rubbed with rotating cloth in one direction, so that an alignment film is formed. This is how the color filter substrate is fabricated.
The following describes the assembling step.
First, a sealing material made of a thermosetting epoxy resin is applied by screen printing onto either the active-matrix substrate and the color filter substrate into a frame pattern lacking a part that serves as a liquid crystal inlet later, and spherical spacers each having a diameter equivalent to the thickness of the liquid crystal layer and made of plastic or silica are scattered on the other substrate. It is possible to form spacers on the black matrix of the color filter substrate or on the metal wires of the active-matrix substrate by the PEP technique instead of scattering spacers.
Next, the active-matrix substrate and the color filter substrate are joined on top of each other, and the sealing material is cured.
Finally, the liquid crystal layer is formed by filling the space enclosed by the active-matrix substrate, the color filter, and the sealing material with a liquid crystal material by an evacuation method, applying a UV-curing resin to the liquid crystal inlet, and then sealing the liquid crystal material by UV irradiation. This is how the liquid crystal panel is fabricated.
It should be noted here that the liquid crystal panel 10 shown in
(Example Configuration 2 of a Liquid Crystal Panel)
In the present liquid crystal panel 20, each pixel is provided with a pixel electrode. The pixel 101 has its pixel electrode 17a connected to the data signal line 15Q via a transistor 12a connected to the scanning signal line 16a. The pixel 102 has its pixel electrode 17b connected to the data signal line 15q via a transistor 12b connected to the scanning signal line 16b. The pixel 103 has its pixel electrode 17c connected to the data signal line 15Q via a transistor 12c connected to the scanning signal line 16c. The pixel 104 has its pixel electrode 17d connected to the data signal line 15q via a transistor 12d connected to the scanning signal line 16d. The pixel 105 has its pixel electrode 17e connected to the data signal line 15Q via a transistor 12e connected to the scanning signal line 16e. The pixel 106 has its pixel electrode 17f connected to the data signal line 15q via a transistor 12f connected to the scanning signal line 16f.
Meanwhile, the pixel 111 has its pixel electrode 17A connected to the data signal line 15r via a transistor 12A connected to the scanning signal line 16a. The pixel 112 has its pixel electrode 17B connected to the data signal line 15R via a transistor 12B connected to the scanning signal line 16b. The pixel 113 has its pixel electrode 17C connected to the data signal line 15r via a transistor 12C connected to the scanning signal line 16c. The pixel 114 has its pixel electrode 17D connected to the data signal line 15R via a transistor 12D connected to the scanning signal line 16d. The pixel 115 has its pixel electrode 17E connected to the data signal line 15r via a transistor 12E connected to the scanning signal line 16e. The pixel 116 has its pixel electrode 17F connected to the data signal line 15R via a transistor 12F connected to the scanning signal line 16f.
That is, unlike in the case of the configuration of the liquid crystal panel 10 of
According to the present driving method, as shown in
This causes the pixel potentials (Va, Vb, VA, VB, Vc, Vd, Ve, Vf) to change in the same way as the pixel potentials shown in
Thus, in the frame F1, as shown in
Further, in the frame F2, as shown in
In the present configuration, the data signal line 15q is supplied with a data signal of a positive polarity corresponding to gray during the kth horizontal scanning period, is supplied with a data signal of a positive polarity corresponding to black during the (k+1)th horizontal scanning period, and is supplied with a data signal of a positive polarity corresponding to gray during the (k+2)th horizontal scanning period. Meanwhile, the data signal line 15Q is supplied with a data signal of a negative polarity corresponding to gray during the kth horizontal scanning period, is supplied with a data signal of a negative polarity corresponding to white during the (k+1)th horizontal scanning period, and is supplied with a data signal of a negative polarity corresponding to gray during the (k+2)th horizontal scanning period. That is, at the transition from the kth horizontal scanning period to the (k+1)th horizontal scanning period, the potentials of the data signals that are supplied to the data signal lines 15q and 15Q change in a falling direction (negative direction), and at the transition from the (k+1)th horizontal scanning period to the (k+2)th horizontal scanning period, the potentials of the data signals that are supplied to the data signal lines 15q and 15Q change in a rising direction (positive direction).
For this reason, in the pixel electrode 17a, the pixel potential Va (data signal of a negative polarity corresponding to gray) written during the kth horizontal scanning period changes in a falling direction (negative direction) in the (k+1)th horizontal scanning period due to the parasitic capacitances Csd_aq and Csd_aQ between the pixel electrode 17a and the data signal lines 15q and 15Q, respectively, and changes in a rising direction (positive direction) in the (k+2)th horizontal scanning period due to the parasitic capacitances Csd_aq and Csd_aQ between the pixel electrode 17a and the data signal lines 15q and 15Q, respectively (see
In the present configuration, however, the pixel electrode 17a forms capacitances CaP and Car with the data signal lines 15P and 15r, respectively. The data signal line 15P is supplied with a data signal of a negative polarity corresponding to gray during the kth horizontal scanning period, is supplied with a data signal of a negative polarity corresponding to black during the (k+1)th horizontal scanning period, and is supplied with a data signal of a negative polarity corresponding to gray during the (k+2)th horizontal scanning period. The data signal line 15r is supplied with a data signal of a positive polarity corresponding to gray during the kth horizontal scanning period, is supplied with a data signal of a positive polarity corresponding to white during the (k+1)th horizontal scanning period, and is supplied with a data signal of a positive polarity corresponding to gray during the (k+2)th horizontal scanning period.
For this reason, in the pixel electrode 17a, the pixel potential Va (data signal of a negative polarity corresponding to gray) written during the kth horizontal scanning period changes in a rising direction (positive direction) in the (k+1)th horizontal scanning period due to the capacitances CaP and Car, respectively, and changes in a falling direction (negative direction) in the (k+2)th horizontal scanning period due to the capacitances CaP and Car. This makes it possible to curb the influence of a crosstalk and thus enhance display quality, as in Example Configuration 1.
(Example Configuration 3 of a Liquid Crystal Panel)
Further, the liquid crystal panel 30 has a retention capacitor wire 18g provided for the pixels 101 and 111, a retention capacitor wire 18h provided for the pixels 102, 112, 103, and 113, a retention capacitor wire 18i provided for the pixels 104, 114, 105, and 115, a retention capacitor wire 18j provided for the pixels 106 and 116.
The liquid crystal panel 30 has a retention capacitance Cha formed between the retention capacitor wire 18g and the pixel electrode 17a, a retention capacitance Chb formed between the retention capacitor wire 18h and the pixel electrode 17b, a retention capacitance Chc formed between the retention capacitor wire 18h and the pixel electrode 17c, a retention capacitance Chd formed between the retention capacitor wire 18i and the pixel electrode 17d, a retention capacitance Che formed between the retention capacitor wire 18i and the pixel electrode 17e, and a retention capacitance Chf formed between the retention capacitor wire 18j and the pixel electrode 17f. Similarly, the liquid crystal panel 30 has a retention capacitance ChA formed between the retention capacitor wire 18g and the pixel electrode 17A, a retention capacitance ChB formed between the retention capacitor wire 18h and the pixel electrode 17B, a retention capacitance ChC formed between the retention capacitor wire 18h and the pixel electrode 17C, a retention capacitance ChD formed between the retention capacitor wire 18i and the pixel electrode 17D, a retention capacitance ChE formed between the retention capacitor wire 18i and the pixel electrode 17E, and a retention capacitance ChF formed between the retention capacitor wire 18j and the pixel electrode 17F.
According to the present driving method, as shown in
As shown in
The present liquid crystal panel 30 has its pixel electrodes 17a, 17b, 17c, and 17d provided so that parts thereof overlap the data signal lines 15P, 15q, 15Q, and 15r, respectively, and has its pixel electrodes 17A, 17B, 17C, and 17D provided so that parts thereof overlap the data signal lines 15Q, 15r, 15R, and 15s, respectively.
Further, the present liquid crystal panel 30 has its retention capacitor wire 18g provided in such a way as to overlap the pixel electrodes 17a and 17A, has its retention capacitor wire 18h provided in such a way as to overlap the pixel electrodes 17b, 17B, 17c, and 17C, and has its retention capacitor wire 18i provided in such a way as to overlap the pixel electrodes 17d and 17D.
Moreover, the scanning signal line 16ab functions as the gate electrode of the transistor 12a, which has its source electrode connected to the data signal line 15q and which has its drain electrode connected to a capacitor electrode 37a via a drain drawing electrode 27a. The capacitor electrode 37a is provided above the retention capacitor wire 18g and is connected to the pixel electrode 17a via a contact hole 11a. Further, the scanning signal line 16ab functions as the gate electrode of the transistor 12b, which has its source electrode connected to the data signal line 15Q and which has its drain electrode connected to a capacitor electrode 37b via a drain drawing electrode 27b. The capacitor electrode 37b is provided above the retention capacitor wire 18h and is connected to the pixel electrode 17b via a contact hole 11b.
Similarly, the scanning signal line 16cd functions as the gate electrode of the transistor 12c, which has its source electrode connected to the data signal line 15q and which has its drain electrode connected to a capacitor electrode 37c via a drain drawing electrode 27c. The capacitor electrode 37c is provided above the retention capacitor wire 18h and is connected to the pixel electrode 17c via a contact hole 11c. Further, the scanning signal line 16cd functions as the gate electrode of the transistor 12d, which has its source electrode connected to the data signal line 15Q and which has its drain electrode connected to a capacitor electrode 37d via a drain drawing electrode 27d. The capacitor electrode 37d is provided above the retention capacitor wire 18i and is connected to the pixel electrode 17d via a contact hole 11d. The pixel electrodes 17A, 17B, 17C, and 17D are identical in configuration to the aforementioned pixel electrodes 17a, 17b, 17c, and 17d.
The present liquid crystal panel 30 is configured such that the retention capacitance Cha (see
The present liquid crystal panel 30 provides each set of two pixels with one scanning signal line and one retention capacitor wire and therefore can reduce the number of scanning signal lines and retention capacitor wires in comparison with the liquid crystal panel 10 shown in
(Example Configuration 4 of a Liquid Crystal Panel)
Further, the pixel 111 has its pixel electrode 17Am connected to the data signal line 15r via a transistor 12Am connected to the scanning signal line 16a, and has its pixel electrode 17As connected to the data signal line 15r via a transistor 12As connected to the scanning signal line 16a. The pixel 112 has its pixel electrode 17Bm connected to the data signal line 15R via a transistor 12Bm connected to the scanning signal line 16b, and has its pixel electrode 17Bs connected to the data signal line 15R via a transistor 12Bs connected to the scanning signal line 16b. The pixel 113 has its pixel electrode 17Cm connected to the data signal line 15r via a transistor 12Cm connected to the scanning signal line 16c, and has its pixel electrode 17Vs connected to the data signal line 15r via a transistor 12Cs connected to the scanning signal line 16c.
The liquid crystal panel 30 has a retention capacitance Chas formed between the retention capacitor wire 18g and the pixel electrode 17 as, a retention capacitance Cham formed between the retention capacitor wire 18h and the pixel electrode 17am, a retention capacitance Chbs formed between the retention capacitor wire 18h and the pixel electrode 17bs, a retention capacitance Chbm formed between the retention capacitor wire 18i and the pixel electrode 17bm, a retention capacitance Chcs formed between the retention capacitor wire 18i and the pixel electrode 17cs, and a retention capacitance Chcm formed between the retention capacitor wire 18j and the pixel electrode 1 cm. Similarly, the liquid crystal panel 30 has a retention capacitance ChAs formed between the retention capacitor wire 18g and the pixel electrode 17As, a retention capacitance ChAm formed between the retention capacitor wire 18h and the pixel electrode 17Am, a retention capacitance ChBs formed between the retention capacitor wire 18h and the pixel electrode 17Bs, a retention capacitance ChBm formed between the retention capacitor wire 18i and the pixel electrode 17Bm, a retention capacitance ChCs formed between the retention capacitor wire 18i and the pixel electrode 17Cs, and a retention capacitance ChCm formed between the retention capacitor wire 18j and the pixel electrode 17Cm.
By applying the driving method shown in
Thus, the present liquid crystal panel 40 can display a halftone by using bright and dark subpixels and can therefore enhance viewing angle characteristics.
(Example Configuration 5 of a Liquid Crystal Panel)
The aforementioned Example Configurations 1 to 4 are configured to carry out dot-reversal driving. However, the present invention is not limited to this, but may be configured to carry out line-reversal driving.
According to the present driving method, as shown in
Moreover, the present driving method makes it possible to suppress display unevenness that occurs when such a checkered pattern image as shown in
That is, as shown in
For this reason, in the pixel electrode 17a, for example, the pixel potential Va (data signal of a positive polarity corresponding to gray) written during the kth horizontal scanning period changes in a rising direction (positive direction) in the (k+1)th horizontal scanning period due to the parasitic capacitances Csd_aq and Csd_aQ between the pixel electrode 17a and the data signal lines 15q and 15Q, respectively, and changes in a falling direction (negative direction) in the (k+2)th horizontal scanning period due to the parasitic capacitances Csd_aq and Csd_aQ between the pixel electrode 17a and the data signal lines 15q and 15Q, respectively. This causes display unevenness to occur.
In the present configuration, however, the pixel electrode 17a forms capacitances CaP and Car with the data signal lines 15P and 15r, respectively. The data signal line 15P is supplied with a data signal of a negative polarity corresponding to gray during the kth horizontal scanning period, is supplied with a data signal of a negative polarity corresponding to white during the (k+1)th horizontal scanning period, and is supplied with a data signal of a negative polarity corresponding to gray during the (k+2)th horizontal scanning period. The data signal line 15r is supplied with a data signal of a positive polarity corresponding to gray during the kth horizontal scanning period, is supplied with a data signal of a positive polarity corresponding to black during the (k+1)th horizontal scanning period, and is supplied with a data signal of a positive polarity corresponding to gray during the (k+2)th horizontal scanning period.
For this reason, in the pixel electrode 17a, the pixel potential Va (data signal of a positive polarity corresponding to gray) written during the kth horizontal scanning period changes in a falling direction (negative direction) in the (k+1)th horizontal scanning period due to the capacitances CaP and Car, respectively, and changes in a rising direction (positive direction) in the (k+2)th horizontal scanning period due to the capacitances CaP and Car. Thus, the changes in potential due to the parasitic capacitances can be canceled by the changes in potential due to the capacitances formed between the pixel electrode and the data signal lines corresponding to both adjacent columns of pixels, respectively. This makes it possible to curb the influence of a crosstalk and thus enhance display quality.
Similarly, in the pixel electrode 17b, the pixel potential Vb (data signal of a negative polarity corresponding to gray) written during the kth horizontal scanning period changes in a rising direction (positive direction) due to the parasitic capacitances Csd_bq and Csd_bQ between the pixel electrode 17b and the data signal lines 15q and 15Q, respectively, but changes in a falling direction (negative direction) due to the capacitances CbP and Cbr in the (k+1)th horizontal scanning period, and changes in a falling direction (positive direction) due to the parasitic capacitances Csd_bq and Csd_bQ between the pixel electrode 17b and the data signal lines 15q and 15Q, respectively, but changes in a falling direction (negative direction) due to the capacitances CbP and Cbr in the (k+2)th horizontal scanning period. Thus, the changes in potential due to the parasitic capacitances can be canceled by the changes in potential due to the capacitances formed between the pixel electrode and the data signal lines corresponding to both adjacent columns of pixels, respectively. This makes it possible to curb the influence of a crosstalk and thus enhance display quality.
Thus, even a configuration in which line-reversal driving is carried out makes it possible to suppress display unevenness that occurs in the column-wise direction.
By interchanging the polarities of the data signals that are supplied to the data signal lines 115q and 15Q in each of the liquid crystal panels of Example Configurations 2 to 4, line-reversal driving can be achieved, and display unevenness that occurs in such a checkered pattern display image as shown in
(Configurations of a Liquid Crystal Display Unit and a Liquid Crystal Display Apparatus)
Finally, example configurations of a liquid crystal display unit and a liquid crystal display apparatus of the present invention are described. In each of the example configurations, the present liquid crystal display unit and the present liquid crystal display apparatus are configured in the following manner. That is, two polarizers A and B are attached to both sides of the liquid crystal panel, respectively, so that the polarizers A and B have their axes of polarization orthogonal to each other. Each of the polarizers may have an optical compensator or the like joined on top thereof. Next, as shown in (a) of
(a) of
The source driver shown in (a) of
Although the configuration of the source driver described above uses Vcom as a refresh potential, this does not imply any limitation. For example, it is possible to calculate in advance an appropriate refresh potential in accordance with the level of a signal potential supplied to a data signal line during the immediately preceding horizontal scanning period and a signal potential to be supplied to the same data signal line during the current horizontal scanning line, and to supply the refresh potential to the data signal line. A configuration of the source driver in this case is shown in
The term “polarity of a potential” as used in the present application means whether the potential is high (positive) or low (negative) with respect to a reference potential. The reference potential here may be Vcom (common potential), which is the potential of the common electrode (counter electrode), or may be any other potential.
The display control circuit receives a digital video signal Dv, a horizontal synchronizing signal HSY, a vertical synchronizing signal VSY, and a control signal Dc from an external signal source (e.g., a tuner). The digital video signal Dv represents an image to be displayed. The horizontal synchronizing signal HSY and the vertical synchronizing signal VSY correspond to the digital video signal Dv. The control signal Dc serves to control a display operation. Further, the display control circuit generates a data start pulse signal SSP, a data clock signal SCK, a charge share signal sh, a digital image signal DA (which is a signal corresponding to the video signal Dv), a gate start pulse signal GSP, a gate clock signal GCK, and a gate driver output control signal (scanning signal output control signal) GOE in accordance with the signals Dv, HSY, VSY, and Dc thus received, and then outputs the signals SSP, SCK, sh, DA, GSP, GCK, and GOE. The signals SSP, SCK, sh, DA, GSP, GCK, and GOE serve as signals for causing the display section to display the image represented by the digital video signal Dv. The digital image signal DA represents the image to be displayed.
More specifically, after adjusting the timing and the like of the video signal Dv as needed in an internal memory, the display control circuit outputs the video signal Dv as the digital image signal DA, generates the data clock signal SCK as a signal composed of pulses corresponding to each separate pixel of the image represented by the digital image signal DA, generates the data start pulse signal SSP in accordance with the horizontal synchronizing signal HSY as a signal that is at a high level (H level) for a predetermined period of time every single horizontal scanning period, generates the gate start pulse signal GSP in accordance with the vertical synchronizing signal VSY as a signal that is at a H level for a predetermined period of time every single frame period (single vertical scanning period), generates the gate clock signal GCK in accordance with the horizontal synchronizing signal HSY, and generates the charge share signal sh and the gate driver output control signal GOE in accordance with the horizontal synchronizing signal HSY and the control signal Dc.
Of the signals thus generated by the display control circuit, the digital image signal DA, the charge share signal sh, a signal POL for controlling the polarity of a signal potential (data signal potential), the data start pulse signal SSP, and the data clock signal SCK are inputted to the source driver, and the gate start pulse signal GSP, the gate clock signal GCK, and the gate driver output control signal GEO are inputted to the gate driver.
In accordance with the digital image signal DA, the data clock signal SCK, the charge share signal sh, the data start pulse signal SSP, and the polarity reversal signal POL, the source driver generates analog potentials (signal potentials) in sequence every single horizontal scanning period, the analog potentials being equivalent to the values of pixels in each scanning signal line of the image represented by the digital image signal DA, and then outputs these data signals to data signal lines (e.g., 15q and 15Q).
The gate driver generates a gate on pulse signal in accordance with the gate start pulse signal GSP, the gate clock signal GCK, and the gate driver output control signal GOE and outputs these signals to the scanning signal lines, thereby selectively driving the scanning signal lines.
By the source driver and the gate driver thus driving the data signal lines and the scanning signal lines of the display section (liquid crystal panel), a signal potential is written to each pixel electrode through a data signal line via a transistor (TFT) connected to the scanning signal line selected. This causes a voltage to be applied to the liquid crystal layer of each subpixel, whereby the amount of transmission of light from the backlight is controlled and the image represented by the digital video signal Dv is displayed in each subpixel.
Next, an example configuration is described in which the present is applied to a television receiver.
In the liquid crystal display apparatus 800 thus configured, the Y/C separation circuit 80 receives a composite color picture signal Scv serving as a television signal from an outside source, separates the composite color picture signal Scv into a luminance signal and a color signal, and sends the luminance signal and the color signal to the video chroma circuit 81. The video chroma circuit 81 converts the luminance signal and the color signal into an analog RGB signal corresponding to three primary colors of light, and sends the analog RGB signal to the A/D converter 82. The A/D converter 82 converts the analog RGB signal into a digital RGB signal, and sends the digital RGB signal to the liquid crystal controller 83. Meanwhile, the Y/C separation circuit 80 extracts horizontal and vertical synchronizing signals from the composite color picture signal Scv sent from the outside source, and sends these synchronizing signals to the liquid crystal controller 83 via the microcomputer 87.
The liquid crystal display unit 84 receives the digital RGB signal from the liquid crystal controller 83 at a predetermined timing together with a timing signal based on the synchronizing signals. Further, the gradation circuit 88 generates the respective gradation potentials of the three primary colors R, G, and B of a color display, and supplies these gradation potentials to the liquid crystal display unit 84. The liquid crystal display unit 84 uses its internal source and gate drivers and the like to generate driving signals (data signals=signal potentials, scanning signals, etc.) in accordance with the RGB signal, the timing signal, and the gradation potentials, and uses its internal liquid crystal panel to display a color image in accordance with the driving signals. In order for an image to be displayed by the liquid crystal display unit 84, it is necessary to irradiate the back of the liquid crystal panel provided in the liquid crystal display unit with light. In this liquid crystal display apparatus 800, the back surface of the liquid crystal panel is irradiated with light by the backlight driving circuit 85 driving the backlight 86 under control of the microcomputer 87. Overall control of the system, including the above process, is carried out by the microcomputer 87. As a picture signal (composite color picture signal) that is sent from an outside source, a picture signal that is taken by a camera, a picture signal that is supplied via an Internet line, or the like, as well as a picture signal based on a television broadcast, can be used. The liquid crystal display apparatus 800 is capable of displaying images based on various picture signals.
In a case where the liquid crystal display apparatus 800 displays an image based on a television broadcast, a tuner section 90 is connected to the liquid crystal display apparatus 800 as shown in
It should be noted that the present liquid crystal display apparatus can also be applied to a digital television. The present digital television is schematically configured to include a speaker, a digital broadcasting antenna, a digital tuner, a digital demodulation section, a separation section (DMUX), a video decode/capture section, a picture processing section, a display control section, an audio decode section, an sound output control section, a select section, an EPG/OSD reservation processing section, a remote controller light-receiving section, a communication control section, a nonvolatile memory, an IP broadcasting tuner, and a CPU. A well-known configuration can be applied to each component of the present digital television except for the components of the present liquid crystal display apparatus.
As described above, a display device according to the present invention is a display device including: a plurality of scanning signal lines; and a plurality of data signal lines, two of which are provided for each column of pixels containing a plurality of pixels arranged in a column-wise direction in which the data signal lines extend, in each column of pixels, a pixel electrode contained in either of two pixels adjacent to each other in the column-wise direction and a pixel electrode contained in the other one of the two pixels adjacent to each other being connected to different data signal lines via transistors, respectively, for a first, a second, and a third columns of pixels arranged in sequence, each pixel electrode contained in the second column of pixels forming a capacitance with either of the two data signal lines provided for the first column of pixels and forming a capacitance with either of the two data signal lines provided for the third column of pixels.
According to the foregoing configuration, the influence of a crosstalk due to parasitic capacitances formed between each pixel electrode and data signal lines corresponding to the pixel, respectively, can be curbed by capacitances formed between that pixel electrode and data signal lines corresponding to both adjacent columns of pixels, respectively. This makes it possible to suppress a change in pixel potential in each pixel electrode and thus enhance the display quality of the liquid crystal display apparatus.
The display device can also be configured such that for the first, the second, and the third columns of pixels arranged in sequence, each pixel electrode contained in the first column of pixels forms a capacitance with either of the two data signal lines provided for the second column of pixels, and each pixel electrode contained in the third column of pixels forms a capacitance with the other one of the two data signal lines provided for the second column of pixels.
The display device can also be configured such that each pixel electrode contained in the second column of pixels is placed in such a way as to overlap either of the two data signal lines provided for the first column of pixels and is placed in such a way as to overlap either of the two data signal lines provided for the third column of pixels.
The display device can also be configured such that: each pixel electrode contained in the first column of pixels is placed in such a way as to overlap either of the two data signal lines provided for the second column of pixels; and each pixel electrode contained in the third column of pixels is placed in such a way as to overlap the other one of the two data signal lines provided for the second column of pixels.
The display device can also be configured such that: N (where N is an integer of 1 or greater) of the scanning signal lines is/are simultaneously selected at a time; and a pixel electrode contained in either of two pixels adjacent to each other in the column-wise direction and a pixel electrode contained in the other one of the two pixels adjacent to each other are connected to transistors, respectively, each of which is connected to N scanning signal lines that are simultaneously selected.
The display device can also be configured such that: N is 2 so that two of the scanning signal lines are simultaneously selected at a time; and the pixel electrode contained in either of the two pixels adjacent to each other is connected to a transistor connected to either of two scanning signal lines that are simultaneously selected, and the pixel electrode contained in the other one of the two pixels adjacent to each other is connected to a transistor connected to the other one of the two scanning signal lines that are simultaneously selected.
The display device can also be configured such that during an identical horizontal scanning period, the two data signal lines provided for each column of pixels are supplied with data signals that are different in polarity from each other.
The display device can also be configured such that each pixel is provided with a plurality of pixel electrode.
To the display device, dot-reversal driving or line-reversal driving can be applied.
A liquid crystal display apparatus includes such a display device. A television receiver includes: such a liquid crystal display apparatus; and a tuner section which receives a television broadcast.
The present invention is not limited to the description of the embodiments above. An embodiment based on a proper alteration of the embodiment or on a proper combination of the embodiments is encompassed in the embodiments of the present invention.
A liquid crystal panel of the present invention is suitable, for example, to a liquid crystal television.
Number | Date | Country | Kind |
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2010-150279 | Jun 2010 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2011/060886 | 5/11/2011 | WO | 00 | 11/14/2012 |