JP3236681B2 - Liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a liquid crystal display device having a fixed display portion formed of pixels having a larger area than other pixels in a display portion.

[0002]

2. Description of the Related Art As is well known, in a liquid crystal display device, a pair of glass substrates provided with stripe-shaped transparent electrodes are arranged facing each other at a predetermined interval so that the electrodes are orthogonal to each other, and a liquid crystal is sealed between them. The structure is common. In this case, each intersection of the electrodes becomes a minute pixel, which is arranged in a matrix to form a display unit. By applying a driving voltage to a specific electrode, the orientation state of the liquid crystal is selectively changed. The display is performed in an arbitrary pattern by the combined effect with the polarizing plate and the retardation film.

Although the shape and area of each pixel are generally the same, it is necessary to display specific characters and symbols in the display portion of the liquid crystal display element or to change the display pattern for the purpose of decoration or the like. In some cases, there is no fixed display portion, and since this portion does not need to be configured by combining a large number of pixels, a large-area pixel is formed in a shape corresponding to the display pattern by widening the width of the electrode. For this reason, the aperture ratio becomes larger than that of the peripheral portion, and the average brightness when the liquid crystal is operated to be in the light-transmitting state becomes higher than that of the other portions of the display portion, thereby deteriorating the uniformity of display. The problem arises.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of this point, and has been made to eliminate non-uniformity of display in a liquid crystal display device having a fixed display portion.

[0005]

In order to solve the above-mentioned problems, according to the present invention, a pair of substrates each provided with a transparent electrode are opposed to each other via a liquid crystal, and a pixel is formed in a region where both transparent electrodes overlap. Is formed, in a liquid crystal display element in which a non-opening portion is formed in a region between pixels where the transparent electrodes do not overlap, a display portion is formed by a number of minute pixels, and another display portion is formed in the display portion. A fixed display portion formed of one or more pixels having a larger area than the pixels is configured;
In addition, in the large-area pixel forming the fixed display portion, another non-opening portion is provided in which the transparent electrode does not overlap and does not become a light-transmitting state even when a liquid crystal operating voltage is applied, and the display portion and the fixed display portion The size of the non-opening portion of the fixed display portion is selected so that the aperture ratio of the fixed display portion is substantially the same.

[0006]

Since the aperture ratio of the fixed display portion is reduced by providing the non-opening portion, the size of the non-opening portion is appropriately adjusted by devising the shape of the transparent electrode so that the aperture ratio becomes equal to other portions. In this case, the average luminance of the fixed display unit is reduced, and the luminance and contrast of the entire display unit become uniform.

[0007]

Next, one embodiment shown in the drawings will be described. FIG. 1 is a plan view of a main part of a liquid crystal display element of an embodiment, wherein 1 is a display section, 2 is a normal pixel, 3 and 3a are pixels having a larger area than the pixel 2, and 4 is formed by pixels 3 and 3a. The fixed display portion 5 is a non-opening portion formed between the pixels, and 6 and 6a are other non-opening portions formed in the fixed display portion 4. Although not a cross section, the non-opening portions 5 and 6 are shown with oblique lines.

FIG. 3 shows a case where the non-opening portions 5 and 6 are not provided for comparison. The display portion 1 in which the non-opening portion 5 is provided between the pixels 2 and 2 having a small area is shown. The aperture ratio of the fixed display unit 4 is naturally larger than the average aperture ratio. For this reason, in the case of FIG. 3, the brightness of the fixed display unit 4 when the liquid crystal is activated to be in the light-transmitting state is reduced by the peripheral display unit 1.
And display uniformity is impaired. In contrast, in the case of FIG. 1, the average aperture ratio can be reduced to a value equal to or close to the aperture ratio of the display unit 1 by the non-opening portions 6 and 6a in the fixed display unit 4. In addition, it is possible to make the overall brightness and contrast uniform, and it is possible to obtain a liquid crystal display element with a uniform display.

FIG. 2 is a view illustrating the shape of a transparent electrode for obtaining the liquid crystal display device as shown in FIG. 11 and 12
Is a pair of glass substrates, 13 and 14 are electrodes provided on the glass substrate 11, 15 and 16 are electrodes provided on the glass substrate 12, and the electrodes 14 and 16 are formed to form a large-area pixel 3. It is wider. The electrodes 14 and 16 are provided with a plurality of slits 14a and 16a, respectively, along the longitudinal direction. These slits 14a and 16a can be formed in a non-opening portion as shown in FIG. 1 when the glass substrates 11 and 12 are combined by appropriately selecting a forming pattern when forming electrodes on the glass substrates 11 and 12. 6, 6a are provided in such a shape as to be constituted. The slits 14a, 16a
Are provided in such a shape that the electrodes 14 and 16 are not separated.

The shapes of the non-opening portions 6 and 6a in the above-described embodiment are merely examples, and may be arbitrarily selected according to the shape of the fixed display portion 4. In the embodiment, the opposed wide electrodes 14 and 6a are formed. Although slits 14a and 16a are provided on both of the electrodes 16, it is sufficient to provide slits on one of the electrodes as long as a sufficient effect can be obtained.

The following table compares the characteristics of a fixed display portion (aperture ratio = 1) formed of large-area pixels and a normal display portion in which fine pixels are arranged in a matrix with respect to light transmittance. It was done. Here, the display units in the matrix arrangement have a pixel pitch of 0.33 × 0.33, a pixel size of 0.3 × 0.3, an aperture ratio of 0.83, and the number of pixels = 640.
× 480 was used.

[Table 1]

In Table 1, the difference in the transmittance between the fixed display unit and the normal display unit is due to the difference in the aperture ratio between them. It feels significantly higher than the part. Therefore, providing the non-opening portion in the fixed display portion and lowering the aperture ratio according to the present invention can be said to be a very effective means for making the brightness and contrast of the liquid crystal display element uniform. Note that if the aperture ratio of the fixed display unit is within ± 10% of the aperture ratio of the other parts of the display unit, there is almost no difference in brightness when viewed with the naked eye, so that the aperture ratios of the two are completely equal. No need.

[0013]

As is apparent from the above embodiments, the present invention relates to a liquid crystal display device having a fixed display portion formed of pixels having a larger area than other pixels in the display portion, wherein the transparent electrode is provided. A non-opening portion that does not overlap and does not enter a light-transmitting state even when a liquid crystal operating voltage is applied is provided in the fixed display portion. That is, by appropriately selecting the shape of the electrodes, the aperture ratio of the fixed display unit can be reduced to be substantially the same as that of the other parts, and the aperture ratio of the non-opening unit can be reduced to the aperture ratio of the peripheral display unit. , The brightness of the fixed display unit can be reduced and the brightness and contrast of the entire display unit can be made uniform, and a liquid crystal display device with good display quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of an embodiment of the present invention.

FIG. 2 is a perspective view showing a structure of a transparent electrode in the embodiment.

FIG. 3 is a plan view of a main part of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Display part 2 Normal pixel 3,3a Large area pixel 4 Fixed display part 5,6,6a Non-opening part 13,14,15,16 Electrode 14a, 16a Slit part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1343 G02F 1/1333

Claims (1)

(57) [Claims] A pair of substrates, each having a transparent electrode provided thereon, are opposed to each other via a liquid crystal, and pixels are formed in a region where both transparent electrodes overlap, and a non-opening region is formed in a region between pixels where the transparent electrodes do not overlap. In the liquid crystal display element in which the portion is configured,
Together with the display unit is constituted by a number of minute pixels; 1 or double the area larger than the other pixels in the display unit
A fixed display portion composed of a number of pixels is formed, and a transparent electrode does not overlap in a large-area pixel forming the fixed display portion , so that a transparent state does not occur even when a liquid crystal operating voltage is applied. only set the other non-opening portion, the opening of the fixed display unit and the display unit
Adjust the size of the non-opening part of the fixed display unit so that the
A liquid crystal display element characterized by being selected .