JPS63168689A - Color liquid crystal display device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) This invention relates to a color liquid crystal display device using a combination of three primary color filters and a liquid crystal shutter.

(Prior Art) In recent years, liquid crystal display panels have attracted attention due to their advantages such as low power consumption, and are often used as monitor displays for watches and computer-related devices. Conventionally, liquid crystals were used simply as an on/off shutter for light, and many had relatively simple screens with black and white displays.

There are various methods of color display using liquid crystal panels, but there are three
The method using primary color filters is the most promoted. The reason for this is that the properties of the twisted nematic mode of liquid crystals have been investigated, and the color reproduction range is wide.

FIG. 5 shows an example of a conventional color liquid crystal panel using a combination U of a twisted nematic liquid crystal and a color filter. In this figure, R11, R12°...R21.
. . . etc. are part of the red filter, G11. G12゜...
・G21...etc. is a part of one green filter, 811.81
2. ...B21... etc. indicate a part of the 17 color filters, and each color filter part (hereinafter referred to as primary color part) indicates one part of the image.
It corresponds to pixels. In addition, the three primary color parts are alternately shifted by half a pixel in the horizontal direction (hereinafter referred to as the X direction) between odd and even lines, so that each of the three primary colors forms the apex of a triangle, and, for example, the odd lines RGBR...
The even-numbered lines have a BRGB... arrangement. As a result, the RGB arrangement becomes a delta shape, making vertical and diagonal lines less noticeable.

A liquid crystal shutter consisting of a plurality of liquid crystal cells partitioned corresponding to each primary color portion is disposed to face the primary color portion. This liquid crystal shutter has liquid crystal filled between a pair of transparent electrodes, and the shutter operation of the liquid crystal is controlled by a thin film transistor TPT in this example.

The above thin film transistor TPT is the number of liquid crystal cells.

That is, only the primary color part of the color filter is provided, and it is formed on the transparent electrode on the side of the pair of electric bridges that is not used as a common electrode. As shown in FIG. 5, this formation position is the lower right corner of the primary color portion forming each square. The reason why the thin film transistor TPT is brought to the corner of the rectangular primary color section in this way is because the thin wAl~transistor TFT is placed in the scanning line L1.
L2. L3. L4゜L5... and signal line RB1
, GBI, BGI.

This is to connect with RB2... as close as possible. Note that the numbers in each primary color section indicate that the three primary color input signals correspond to thin film transistors TPT operated by signals sampled at the same timing. For example, R51, G51.851 is TFT51-1, TF
T51-2, TFT51-3, R54, G5
4. 854 is TFT54-1, TPT54-2,
Each TFT 54-3 performs a filter function. In this case, the thin film transistor TFT51-1
, TFT51-2, TFT51-3, and T
F T54-1, T F T54-2, T F
T54-3 is an element φ that is driven with the same sampling information when scanning line L5 is scanned.

Figure 56 shows the configuration of a liquid crystal cell, with one cell (
10) is arranged between the scanning line L and the signal line SG, and includes the thin film transistor TPT, the transparent electrode TI,
A scanning signal is supplied via a scanning line L to a scanning electrode P1 connected to a gate G of the TPT, and a signal electrode connected to a drain D of the TPT. A primary color signal is supplied to P2 via a signal line SG. And TPT source S
is connected to one transparent electrode T1, and the other transparent electrode T2 is connected to a common potential (ground).

In this way, one pixel is configured.

FIG. 7 is a block diagram showing an example of a circuit for driving the liquid crystal panel having the above configuration. Reference numeral 11 denotes a liquid crystal panel, which is driven by an X-direction driver 12 and a Y-direction driver 13. Further, the output line of the X-direction driver 12 corresponds to the signal line SG in FIG. 6, and the output line of the Y-direction driver 13 corresponds to the scanning line L.

On the other hand, terminals 14, 15, and 16 are input terminals to which 0 primary color signals RGB are introduced. The signals from these terminals 14, 15, and 16 are input to the polarity switching circuit 17, and the polarity is alternately inverted at the timing of the vertical synchronizing signal Vsy from the terminal 21, resulting in a signal QR'G=B'. The reason why the polarity of the primary color signal is switched every vertical scanning period in this way is that durability decreases when a voltage of the same polarity is continuously applied to the liquid crystal.

Next, the signal R=G''B- from the polarity switching circuit 17 is input to the color switching circuit 18, where the primary color signal is switched for each line. This is done because the output RB is made different for odd and even lines.

For example, R'G'B when scanning odd lines as GR and BG.
-, when even-numbered lines are scanned, it is cut so that B'R=G=. As a result, the signal supplied via the X-direction driver 12 is, for example, signal line RB1 is Ll.
When L2 is being scanned, it is switched to lead the signal of R', and when L2 is being scanned, it is switched to lead the signal of B'.

Note that the memory timing of the line memory 19 is controlled by the horizontal open signal Hsy from the terminal 20, and stores three primary color signals for one horizontal scanning period. Then, the stored signal is supplied to the X-direction driver 12 at the timing of the next vertical synchronization signal.

In such a panel type display device, when a bias is applied to the gate of the thin film transistor TPT shown in FIG. 6, conduction occurs between the drain and source, and the signal from the signal line SG at that time is applied to the transparent electrode T1. A potential difference is generated between the transparent electrodes TI and T2, and a light shutter operation is performed according to the voltage between the transparent electrodes TI and T2. and,
For example, when displaying white, in FIG. 5, signals at predetermined levels are supplied to the signal lines R[31, GRl, BGl, respectively, and the scanning signals from the scanning lines L1, L2, . . . B11→
B21°R21, G21→R31, G31. B31→
B41. Liquid crystal layer L D like R41, G41...
becomes transparent.

The conventional circuit shown in FIG. 7 requires a color switching circuit 18 to switch the primary color signals supplied to the line memory 19, and when applied to a pocket TV in particular, a picture frame is required to accommodate the color switching circuit. This has the disadvantage that the area becomes larger and the power consumption increases.

Furthermore, when displaying white in the arrangement of the three primary color sections as shown in Fig. 5, voltage is applied in the horizontal direction in units of RGB. If the dot is made up of three pixels each containing three primary color parts, it has the disadvantage that it becomes long in the horizontal direction.

(Problems to be Solved by the Invention) In conventional liquid crystal color display technology, in order to arrange the color filters of the liquid crystal panel in a delta shape, RGB is arranged in even and odd lines! i'2, which has the disadvantage of requiring a color switching circuit 18 for display driving. Furthermore, when displaying white, the arrangement is such that all RGB in the horizontal direction is driven, which has the disadvantage that one dot becomes longer in the horizontal direction, reducing the resolution of the image.

It is an object of the present invention to solve the above-mentioned problems and provide a liquid crystal color display device that provides high-resolution display using a more natural delta arrangement without performing color switching.

[Structure of the Invention] (Means for Solving the Problems) This invention arranges and arranges a plurality of liquid crystal cells constituting each R, G, and B pixel on a plurality of lines in a predetermined repeating order.
, and the liquid crystal cells are regularly arranged with odd and even lines shifted by half a pixel, each liquid crystal cell having a signal electrode and a scanning electrode, and each liquid crystal cell group arranged in a direction perpendicular to each line. A plurality of RlG and B columns are set by connecting pixels of the same color in every odd numbered lines, and primary color signals are supplied to each signal electrode of the liquid crystal cell located on each of these columns, and a direction perpendicular to each of the lines is set. a signal supply means for connecting pixels of the same color on each even numbered line to set a plurality of columns of R2O and B, and supplying a primary color signal to each signal electrode of a liquid crystal cell located in each column; Among the lines, set a plurality of common lines with an odd number line and the following even number line as one common line,
and a scanning signal supply means configured to supply a common scanning signal to each scanning electrode of the liquid crystal cells located on each common line, so that the three primary color sections that operate simultaneously as filters are always in a delta shape. It is characterized by

(Function) In general, color filters used in color liquid crystal displays are arranged so that a portion of the primary color filters form a delta shape. Then, each line is 2 to 1
Alternatively, an image with 1:2 delta-shaped three primary color parts is displayed, and the image is not horizontally elongated as in the past, so resolution can be improved. Further, since the three primary color signals are supplied corresponding to each delta type three primary color portion every two lines, there is no need to perform color switching.

(Example) An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a block diagram showing an embodiment of a liquid crystal color display device according to the present invention, and shows a part of the display panel section.

This display panel is composed of two layers, a color filter and a liquid crystal shutter, as before, and the arrangement of the primary color parts is RGB..., BRG..., respectively, and odd number lines and even number lines. This is a configuration in which a half-pixel shift is performed.

However, the thin film transistors T corresponding to these primary color part columns
The PT is formed at the lower right corner of the primary color part row for odd numbered lines, and at the lower right corner for even numbered lines. That is, the thin film transistors TPT for the even-numbered line side primary color part columns are formed in the same way as the thin film transistors TFTi for the odd-numbered line side primary color part columns. The scanning lines are formed as a plurality of common lines L1.12, L3, etc., with an odd numbered line and the next even numbered line as one common line, and on these common lines L1, L2,... A scanning signal is simultaneously supplied to the scanning electrode (gate of TPT) of each liquid crystal cell.

In addition, the signal line has the same color pixels R11 and R for every odd numbered line.
21, R31, . . . and the same color pixel B11 for every even line. B21. Multiple rows of signal lines [K1
゜B1, G1. R2, B2, G2... are formed. Therefore, the signal lines R1, R2, . . . control only red pixels, the signal lines 81, B2, . . . control only blue pixels, and the signal lines G1, G2, . . . control only green pixels.

The liquid crystal display panel according to this embodiment is configured as described above.

FIG. 2 is a block diagram showing an example of a circuit for driving the liquid crystal display panel of FIG. 1. In FIG. 2, the same parts as in FIG. 7 are denoted by the same reference numerals, and 22 is the liquid crystal display panel in FIG.

As explained in FIG. 1, the signal lines R1, G1, B1
. . . drives three primary color sections each having one fixed color, so the conventional color switching circuit 18 is no longer necessary.
The output R'G'B- signal of the polarity switching circuit 17 can be directly supplied to the line memory 24. line memory 2
4 transmits the input signal R-G'B= to signal lines R1, R2, R3 . . . , G1 . G2, G3...
and B1, 82.

B3... is distributed to minute signals and held for one horizontal scanning period,
The next horizontal synchronization signal 1-ISV causes the X-direction driver 12 to
It is supplied to the liquid crystal display panel 22 via. Further, the Y-direction driver 23 is synchronized by a vertical synchronization signal, and supplies a pulse for sequentially shifting the scanning line L to the liquid crystal display panel 22 every time a horizontal synchronization signal Hsy is applied.

In this case, the number of output lines of the Y-direction driver 23 can be reduced to half compared to the conventional one.

By the way, in this embodiment, when the scanning line L1 is being scanned, for example, R11, B11 . G11, and R12,81 for signal lines R2 and B2 and inputs to G2.
2, G12 emits primary color light according to the respective input signal levels. Therefore, the color for one dot is determined using a set of three primary color parts RGB that form a delta arrangement as shown in either Fig. 3(a) or (b), and as shown in Fig. 4 which shows the conventional case. , RGB in the horizontal direction are not irradiated at the same time, so the phenomenon that one dot becomes horizontally elongated does not occur.

In this way, the shape of one dot is always a delta shape, which improves screen resolution and eliminates the need to switch color signals. Furthermore, by reducing the number of scanning lines, the number of parts and power consumption can be reduced.

Note that the above embodiment is just an example, and the point is that it is sufficient to drive the odd and even lines at the same time and give respective signals to the delta three primary color portions for these two lines.
For example, a thin film transistor may be formed in the lower left corner for the primary color portion of an odd numbered line, and may be formed in the upper left corner for the primary color portion of an even numbered line. Further, the shape of the primary color portion is not limited to a rectangular shape, and may be, for example, a hexagonal shape.

[Effects of the Invention] As described above, according to the present invention, an ideal delta type display is achieved, and M1g on both sides! This has the effect of contributing to improving the level of performance.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a display panel section showing an embodiment of a color liquid crystal display device according to the present invention, FIG. 2 is a block diagram showing an example of a circuit for driving the device of FIG. 1, and FIGS. 4
The figure is an explanatory diagram for explaining the display effect according to the present invention,
Fig. 5 is a schematic diagram of the panel section of a conventional color liquid crystal display device, Fig. 6 is a circuit diagram of the principle of liquid crystal driving, and Fig. 7 is a block diagram showing an example of a liquid crystal driving circuit in a conventional color liquid crystal display device. be. R1, Bl, G1, R2, . . . are signal lines; L3... is a scanning line, TPT is a thin film transistor, R11, G11. B11. R12・
... is the primary color part. Agent Patent Attorney Nori Chika Kanshu
Hiroshi Uji Figure 1 Figure 2

Claims (1)

[Claims] A plurality of liquid crystal cells constituting each pixel of R (red), G (green), and B (blue) are arranged on a plurality of lines in a predetermined repeating order, and odd and even lines are arranged. A group of liquid crystal cells, each of which has a signal electrode and a scanning electrode, and pixels of the same color on each odd-numbered line arranged in a direction perpendicular to each of the lines, are arranged regularly with a half-pixel offset, and each liquid crystal cell has a signal electrode and a scanning electrode, respectively. A plurality of columns of R, G, and B are connected, and a primary color signal is supplied to each signal electrode of a liquid crystal cell located on each column, and each even numbered line arranged in a direction perpendicular to each line is connected. Connect each same color pixel of R, G,
a signal supply means for setting a plurality of columns of B, and supplying primary color signals to each signal electrode of a liquid crystal cell located in each column; A color liquid crystal display device comprising a scanning signal supply means which sets a plurality of common lines as common lines and supplies a common scanning signal to each scanning electrode of a liquid crystal cell located on each common line. .