JPH07199206A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a display defect in a screen central part by forming pixels in the vicinity of a boundary between a first display part and a second display part smaller than other pixels in the same column. CONSTITUTION:The constitution by one column incorporates a first signal electrode 17, (n) pieces of first scan electrodes 13 intersecting with the electrode 17, a second signal electrode 27, (n) pieces of second scan electrodes 23 intersecting with the electrode 27, (n) pieces of pixels G1-Gn formed on intersections between the first signal electrode 17 and the first scan electrodes 13 and (n) pieces of pixels Gn+1 G2n formed on the intersections between the second signal electrode 27 and the second scan electrodes 23. The pitch T of the pixels G1-G2n is a fixed value, and though it is not changed, the sizes (sizes in the direction of column) of respective pixels are formed so as to be reduced gradually in accordance with approaching to the boundary Xn between the first and second display parts. By such a constitution, no horizontal stripes occurring on the boundary Xn on the screen become conspicuous, and electric field occurs over the whole pixels even when the deviation in a substrate and a patterning defect occur, and the occurrence of the display defect is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device.

[0002]

2. Description of the Related Art A divided matrix display method is known as one of conventional driving methods for matrix liquid crystal display elements. In this display method, for example, the scanning electrodes are divided into two groups, an upper side and a lower side, and the signal electrodes which are independently separated are assigned to each group. This method has the advantages that the contrast ratio of the display image is high and the response speed is fast because the selection period per scan electrode in the frame period is doubled.

FIG. 4 shows signal electrodes 1A and 1B for one column and pixels G1 to Gn and Gn + 1 to G2 for one column of a matrix liquid crystal display element.
The n is shown enlarged. As shown in the figure, at the center of the screen, that is, at the boundary between the two display portions, the two central pixels G
The ends of the signal electrodes 1A and 1B must be aligned within the interval Xn between n and Gn + 1.

[0004]

Conventional pixels G1 to G2n
The interval X1 to X2n-1 is constant and very narrow. Therefore, as shown in FIG. 5 (A), when there is a vertical misalignment between both substrates, or as shown in FIG.
When patterning failure of the ITO (Indium Tin Oxide) film occurs when forming A and 1B, the signal electrodes 1A and
Since there is a portion where the electrodes do not overlap with the pixel at the end of 1B, there is a problem that a display defect occurs and the yield decreases. Further, if the distance between the pixels at the end is widened in advance in consideration of misalignment, that portion becomes dark, and there is a problem that horizontal stripes are visible on the screen. The present invention has been made in view of the above situation, and an object of the present invention is to provide a liquid crystal display element of a split matrix display system in which a display defect in the central portion of the screen is unlikely to occur.

[0005]

In order to achieve the above object, a liquid crystal display element according to the present invention comprises a plurality of first scanning electrodes, first signal electrodes, the first scanning electrodes and the first scanning electrodes. A first display portion including a pixel formed at an intersection with the signal electrode of the second scanning electrode, a plurality of second scanning electrodes, and a second scanning electrode.
And a second display portion which is formed of a pixel formed at an intersection of the second scanning electrode and the second signal electrode and which forms one screen together with the first display portion. In a divided matrix type liquid crystal display device including
A pixel in the vicinity of the boundary between the first display portion and the second display portion is formed smaller than other pixels in the same column.

[0006]

According to the present invention, in the liquid crystal display element of the split matrix display system in which one screen is formed from the first display section and the second display section, the first display section and the second display section are provided. The pixels near the boundary of are formed smaller than other pixels in the same column. According to such a configuration, even if an alignment defect, an etching defect during manufacturing, or the like occurs, the probability that pixels in the vicinity of the boundary will protrude from the intersection of the scanning electrode and the signal electrode is reduced. Yield is improved. Moreover, since the area of the pixel is gradually changed, the line that appears in the interval between the first display section and the second display section becomes inconspicuous, so that the display quality is not affected.

As a concrete method for forming the pixels near the boundary smaller than the other pixels in the same column, for example, the pitch of the pixels may be the same, and the interval between the pixels may be increased toward the boundary. Alternatively, for example, a portion in which the pixel pitch and the interval between the pixels are substantially equal to each other and a portion in which the pixel pitch is the same and the interval between the pixels increases toward the boundary may be arranged.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A split matrix type liquid crystal display element according to an embodiment of the present invention will be described with reference to the drawings. (First Embodiment) FIG. 2 shows the entire basic configuration of a divided matrix type liquid crystal display device of the present embodiment. As shown in the figure, this liquid crystal display element includes a scan driver 11, a scan electrode 13 connected to the scan driver 11, a first signal driver 15, and n lines connected to the first signal driver 15. The first signal electrode 17, the first scan electrode and the first
A first display portion 19 including pixels (not shown) formed at the intersection with the signal electrode of
Second scan electrodes 23 connected in parallel with the second scan electrodes 13, second signal drivers 25, second signal electrodes 27 connected to the second signal drivers 25, The second display unit 29 is formed of pixels (not shown) formed at the intersections of the two scanning electrodes and the second signal electrodes, and constitutes one display unit as a whole.

In the above structure, the signal electrode is formed on one transparent substrate of the liquid crystal display element, the scanning electrode and the light shielding layer for shielding the portion other than the pixel are formed on the other transparent substrate, and the signal electrode is formed on the other transparent substrate. Is light-shielded.

FIG. 1 shows the structure of one column of the liquid crystal display element of this embodiment. As shown in the figure, the configuration for one column includes a first signal electrode 17, n first scanning electrodes 13 (only part of which are shown) intersecting the first signal electrode 17, and a second signal electrode. N intersecting the electrode 27 and the second signal electrode 27
Second scan electrode 23 (only part of which is shown), n pixels G1 to Gn formed at the intersections of first signal electrode 17 and first scan electrode 13, and second signal electrode N pixels Gn + 1 to G2 formed at the intersection of the second scan electrode 23 and the second scan electrode 23.
Including n and. Each pixel is physically composed of a signal electrode and a scanning electrode facing each other, a liquid crystal arranged between them, and a rectangular opening formed in the light shielding film.

In FIG. 1, the pitch T of the pixels G1 to G2n is
Is a constant value and does not change, but the pixel size (width) W
m (m = 1, 2, ..., N, ..., 2n) and the pixel-to-pixel spacing Xm (m = 1, 2, ..., N, ..., 2n-1) It is set to satisfy the following expressions (1) and (2).

W1> W2> ...> Wn Wn + 1 <Wn + 2 <... <W2n (1)

X1 <X2 <... <Xn Xn> Xn + 1> ...> X2n-1 (2)

That is, the shield area of the light shielding film increases as the ends of the first signal electrode 17 and the second signal electrode 27 are approached. Therefore, in this embodiment, the size of each pixel (the size in the column direction) is gradually reduced as it approaches the boundary between the first and second display portions 19 and 29.

According to such a configuration, the screen boundary (X
Even if the horizontal stripes generated in n) are not conspicuous, the vertical alignment of the substrate is misaligned, or the patterning of the signal electrode is defective, the pixel near the boundary is small, so the signal electrode may cover the pixel. Since it is possible to generate an electric field in the entire pixel, no display defect occurs.

(Second Embodiment) FIG. 3 shows the structure of one column of a liquid crystal display element according to the second embodiment of the present invention.
The overall structure of the divided matrix type liquid crystal display device of this embodiment is the same as that of the first embodiment shown in FIG.

As shown in FIG. 3, in this embodiment, the pitch R of the pixels G1 to G2n is constant. The size (width) W1 to Wp of the pixels G1 to Gp is constant, the sizes Wp to Wn of the pixels Gp to Gn sequentially decrease, and the sizes Wn + 1 to Wq of the pixels Gn + 1 to Gq sequentially increase, and the pixels The sizes Wq to W2n of Gq to G2n are constant. Further, the distances X1 to Xp-1 between the pixels G1 to G2n are constant, Xp-1 to Xn sequentially increase, Xn + 1 to Xq gradually decrease, and Xq to X2n-1 are constant. This relationship is expressed by equations (3) and (4).

W1 = W2 = ... = Wp> Wp + 1> Wp + 2> ...> Wn-1> Wn W2n = W2n-1 ... = Wq> Wq-1> Wq-2>.・ ・ ＞ Wn + 2 ＞ Wn + 1 ・ ・ ・ (3)

X1 = X2 = ... = Xp-1 <Xp <... <Xn Xn> Xn + 1> ...> Xq = Xq + 1 = ... = X2n-1 (4 )

Even in such a configuration, the horizontal stripes generated at the boundary (Xn) of the screen are inconspicuous, and even if the alignment of the substrate is misaligned, pixels near the boundary are likely to be located in the intersection, and the display quality is improved. Deterioration is suppressed.

In the first and second embodiments, the first
The pixel size and the interval are targeted with the boundary between the display unit and the second display unit as the target axis, that is, W1 = W2n, W2 =
It is desirable to set W2n-1, ..., Wn = Wn + 1.

In the above embodiment, the size of each opening is adjusted by adjusting the area of the light shielding layer.
That is, although the area of each pixel is determined, when the intersection of the signal electrode and the scanning electrode directly becomes the pixel, the same effect as that of the above-described embodiment can be obtained by changing the width and the interval of the scanning electrode. The method of changing the pixel size is not limited to the above embodiment. Other methods may be used as long as the pixels near the boundary between the first display portion and the second display portion can be formed small. However, it is necessary to avoid a method that causes deterioration of display quality, such as giving an impression that a part of the display screen is distorted.

As described above, according to the liquid crystal display element of this embodiment, the pixel near the boundary between the first display portion and the second display portion of the divided matrix type liquid crystal display element is replaced with another pixel ( Since it is formed smaller than the pixel at the position away from the boundary, even if there is a misalignment of the substrate alignment (vertical direction) or a patterning failure of the signal electrode, the pixel intersects the signal electrode and the scanning electrode. Various devices, such as projection type projectors, OHPs, and Hs, which are located on the upper side, prevent display defects, and use a liquid crystal display device of a divided matrix system.
Available for UD.

[0024]

According to the present invention, it is possible to prevent or reduce the occurrence of display defects in a divided matrix type liquid crystal display device,
The yield can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of one column of a liquid crystal display element according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a split matrix type liquid crystal display element.

FIG. 3 is a diagram showing a configuration for one column of a liquid crystal display element according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of one column of a conventional split matrix type liquid crystal display element.

5A and 5B are diagrams showing a configuration in the vicinity of an end portion of a signal electrode of a conventional split matrix type liquid crystal display element, in which FIG. An example of a case where a patterning failure occurs will be shown.

[Explanation of symbols]

11 ... Scan driver, 13 ... Scan electrode, 15 ... First
Signal driver, 17 ... signal electrode, 19 ... first display portion, 23 ... scanning electrode, 25 ... second signal driver, 2
7 ... Signal electrode, 29 ... Second display portion, G1 to G2n ... Pixel

Claims (3)

[Claims] 1. A plurality of first scanning electrodes, a plurality of first signal electrodes, and pixels formed at intersections of the first scanning electrodes and the first signal electrodes. A first display portion, a plurality of second scanning electrodes, a plurality of second signal electrodes, and pixels formed at intersections of the second scanning electrodes and the second signal electrodes. In the liquid crystal display element of the split matrix system, which comprises a second display section that forms one screen together with the first display section, a liquid crystal display element in the vicinity of the boundary between the first display section and the second display section is provided. A divided-matrix liquid crystal display element characterized in that pixels are formed smaller than other pixels in the same column. 2. The pixels in each column have the same pixel pitch, and the interval between the pixels is larger near the boundary between the first display section and the second display section. The liquid crystal display element described. 3. A pixel in each column has a portion in which the pixel pitch and the interval between pixels are constant, and a portion in which the pixel pitch is constant and the pixel interval is the first display portion and the second display portion. 2. The liquid crystal display element according to claim 1, further comprising a portion that becomes larger as it gets closer to the boundary.