JPS5876877A - Liquid crystal display - 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 (1) Technical Field of the Invention The present invention relates to liquid crystal display devices, and in particular to so-called dust-host type liquid crystal display devices (hereinafter referred to as GH-
(2) Prior Art Regarding Display Devices Using GH-LCD (hereinafter referred to as GH-LCD)
The wide viewing angle, which is one of the characteristics of D, has been attracting attention and it has come to be used for black and white, etc. Furthermore, since it has the potential to ensure visibility even under direct sunlight, its application to instruments, etc. in the second part of automobile dash days is being actively considered.

When applying a GH-LCD to an on-vehicle instrument, colored patterns, numbers, etc. are usually displayed on a black background.
This is desired from the standpoint of visibility, ergonomics, safety, etc.

As a conventional example of achieving such display conditions, a transmitted illumination type display device as shown in FIG. 1 is known. That is, a transparent electrode substrate 11 such as a glass substrate with two transparent electrodes.

A GH-LC in which a nematic liquid crystal 2 with positive dielectric anisotropy in which a dichroic dye is dissolved in a composition ratio that shows black color between 12 and 12 is horizontally aligned and sealed with a sealing material 3.
D 4 and polarizing plate 5 are combined, and a color filter 6t is provided on the back surface in order to obtain a predetermined display color, and furthermore, an illumination light source 7 and a diffuser plate 8t are provided on the back surface to obtain diffused transmitted light.
A liquid crystal display device is constructed by providing the above. This GH-LC
D4 is a so-called negative display type LCD, which appears black due to the strong light absorption of the dye when no voltage is applied, and weak light absorption due to the dichroism of the dye when a voltage is applied.
The transmittance becomes high, and only the next part where an electric field is applied to the black background is displayed in color by the color filter 6.

On the other hand, the one shown in FIG. 2 is known as a reflective liquid crystal display device using a GH-LCD.

This is a transparent electrode substrate 11 a r I 1 b T
11 Mix a dichroic dye between each of e and make a liquid crystal 1
A two-layer GH-LCD 14f is constructed using a sealing material zsl +IBz'fr- in 21m12z',
A color filter 15 is provided on the back surface, and a reflection plate 1'tt- is further provided on the back surface. Double layer liquid crystal zx, 12
The light absorption axes of the snow are oriented so that they are perpendicular to each other, and this allows for high display contrast to be obtained with the reflective type without using a polarizing plate, and for this reason, the brightness of the display segments can also be high. It has become.

(3) Problems with the prior art Since the one in Figure 1 has a transmissive configuration, the display is hardly visible under strong external light such as direct sunlight, or even if it is slightly visible, the display is The brightness is low and high visibility cannot be ensured. That is, ■ In order to increase the amount of transmitted illumination light, the light reflectance of the diffuser plate 8 is
(1) The transparency of the color filter 6 is lowered to obtain sufficient colored display during transmitted illumination; (9) when external light is incident from the front; The reason for this is that the amount of reflected light passing back and forth through the color filter 6 is small. Therefore, with the configuration shown in FIG. 1, it is difficult to ensure high visibility in both the transmission type and the reflection type.

On the other hand, since the design of the one in Figure 2 is optimized as a reflective type, the color filter 15 is also a two-layer type (2) GH
m LCD 14 also has a relatively high transmittance. Therefore, if the reflector 16 is replaced with a semi-transparent reflector and operated as a transmissive type, the background will not be sufficiently dark due to the high transmittance of the GH-LCD 14 and the color filter 15.
Furthermore, the degree of coloring of the display arm turn is low, resulting in poor visibility and display quality.

(4) Purpose of the Invention The present invention provides a GH-LCD that can maintain high visibility and display quality whether it is used as a reflective type under strong external light or as a transmissive type at night. The present invention provides a liquid crystal display device for use.

(5) Summary of the Invention The liquid crystal display device according to the present invention includes a GH-LCD, a color filter provided on the front or back side of the GH-LCD, a semi-transparent reflector provided on the back side of these, and a rear surface of the reflector. an illumination light source provided in the illumination light source, and the illumination light source is provided with the power 2.
- It is characterized by being able to compare the spectral characteristics of 1 as well as the filter. With such a configuration, if the mixed density of the dye in the GH-LCD is set to a density suitable for a transmissive type, and the cuff fill p is set to a transmittance suitable for a reflective type, then when performing either a reflective type or a transmissive type display. Also, it is possible to display a sufficiently colored display with high brightness in the display no-f turn portion and good visibility.

(6) Embodiment of the invention FIG. 3 shows an embodiment of the invention. Single layer GH-LC
D24 is the same as in FIG. 1, transparent electrode substrates 211, 2
11, a nematic liquid crystal 22 with positive electrolytic anisotropy in which a dichroic dye mixed in a composition ratio so as to exhibit black color is dissolved is horizontally aligned and sealed with a sealing material 23. be.

A polarizing plate 25 is provided on the front surface of this GH-LCD 24, a color filter 26 is provided on the back surface, a semi-transparent reflector 27 is provided on the back surface of the color filter 26, and a light source 28 for transmitted illumination is provided on the back surface.

The light source 28 is composed of a 28% incandescent light bulb as a white light source and a filter 28 for light source use. The light source color filter 283 has spectral characteristics similar to those of the color filter 26. Here GH-LC
D z a is adjusted to have a high mixing concentration of the dye suitable for a transmissive type, and the color filter 26 is adjusted to a high transmittance suitable for a reflective type. The semi-transparent reflector 27 used has a reflectance of 50 to 90 inches and a transmittance of about 45 to 5 inches.

In the case of this embodiment, in the presence of strong daytime external light (for example, direct sunlight), the relatively strong reflection characteristics of the semi-transparent reflector 27 and the high transmittance of the color filter 26 reduce the contrast. It is possible to obtain a sufficiently colored display with high visibility and high brightness in the display pattern portion. On the other hand, even when the lighting rung 281f is turned on and used as a transmission type, the concentration of the pigment is optimized for transmission type and is high, so the background warmth may be insufficient and the light may appear to be leaking. Moreover, since the display no-data turn section sees the light transmitted through the color filter 26 and the light source color filter 282, sufficient coloring can be obtained, and a display with high display quality and good visibility can be obtained. be able to. In this way, when the color filter 26 and the light source color filter 2830 are used with half the same hue, even if the intensity of external light is extremely large, the degree of coloration of the display section and the visibility will change. It becomes possible to obtain a liquid crystal display device with less
3. In addition, when using a color correction filter (example: Fuji Photo Film, CC-30C) in combination with the light source color filter 28, it is possible to use an incandescent light bulb 281 as the lighting lamp. Another effective method of use is to suppress changes in the hue of the sphere. Furthermore, when the transmission is used as a type, it is possible to switch the display color to a plurality of colors by using a plurality of illumination rungs and a plurality of corresponding color filters for the light source.

FIG. 4 shows another embodiment. Double-layer GH-3LCD
J4 is a transparent electrode substrate 311 4-3 as in FIG.
1. Two-layer liquid crystal: 4Jl@, 32. Material for sealing! 31133. A transparent reflective plate 36 is installed without the need for a polarizing sheet metal, and a length plate 77g is attached to the back side of the plate. An illumination source 37 is provided, which is composed of an incandescent light bulb 374.7s that is opened and embedded, and a nine-light source filter 37z that is printed on the front surface of a transparent substrate. In this way, by using the transparent blocking plate 371 that has a light guard effect, it is possible to obtain uniform illumination even when the distance between the electric light 314 * 37 m and the semiphonic reflector 360 cannot be large, and the color filter for the light source This is a very effective means to ensure high display quality and high visibility in combination with 37 snow.

FIG. 5 shows yet another embodiment. This includes transparent electrode substrates 411, 41. A GH-LCD 44 in which the liquid crystal 2 is sealed with a sealing material 43 and a polarizing plate 45 are attached and integrated, and a semi-transparent reflective panel with a back force 2 and a filter 46 printed on it is used to illuminate the z+ panel. Light source 4
8 and used it. In this way, the color filter 46 and the abrasives use the light-emitting screen (EL) armpit with the same hue as the light source, which saves space while improving display quality and ensuring visibility. It is effective for achieving this goal.

As a modification of the embodiment shown in FIG. 5, a color filter for a light source was combined with an EL panel that produces a nearly white color. EL - A light source for illumination that uses fluorescent light emitted from a cold cathode discharge tube, etc.
/It is also possible to obtain a high display effect by using it in the same way as an armpit.

(7) Effects of the invention By combining a GH-LCD with a color filter and giving the illumination light source a predetermined spectral characteristic, higher visibility and display quality are ensured under a wider range of usage conditions than with conventional liquid crystal display devices. A liquid crystal display device can be obtained.

[Brief explanation of drawings]

1 and 2 are diagrams showing an example of a liquid crystal display device using a conventional G)l-LCDt, and FIGS. 3 to 5 are diagrams showing liquid crystal display devices according to embodiments of the present invention. 24.34.44...GH-LCD, 75.45...
・Polarizing plate, 26.35.46...Color filter, 2
'1.36.41... Semi-transparent reflector, 28... Light source for illumination, 28 Dish... Internal heat bulb, 28 Snow... Color filter for light source, 37... Light source for illumination, 311...
Transparent substrate, 37! ...Color filter, 31s...
Reflector, J74 #j' S...Incandescent light bulb,
48... Light source for illumination ('EL/4 channel). Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Exit 222222 = Sat 48

Claims (6)

[Claims] (1) A liquid crystal display element that holds a liquid crystal mixed with a dichroic dye between at least two transparent electrode substrates, a color 74 router provided on the front or back side of this liquid crystal display element, and a liquid crystal display for these elements. In a liquid crystal display device having a semi-transparent reflector provided on the back side of an element and a color filter, and an illumination light source provided on the back of the semi-transparent reflector, the color filter is attached to the illumination light source. A liquid crystal display device characterized by having spectral characteristics similar to those of the liquid crystal display device. (2) The liquid crystal display element is a nematic liquid crystal with positive dielectric anisotropy that is horizontally aligned and held between transparent substrates, and a polarizing plate is provided on the front surface of the liquid crystal display element. The liquid crystal display device according to item 1. (3) The liquid crystal display device according to claim 1, wherein the illumination light source is composed of a white light source and a power filter. (4) The liquid crystal display device according to claim 1, wherein the illumination light source is composed of a transparent substrate having a light guide effect in which a white light source is embedded and a color filter. (5) The liquid crystal display device according to claim 1, wherein the illumination light source is composed of an EL/# panel or a color filter. (6) The liquid crystal display device according to claim 1, wherein the irradiation light source uses a fluorescent substance as a light emitter.