JPS60117216A - Accumulation type liquid crystal display element for positive display - Google Patents

Abstract

PURPOSE:To make display in black on a while ground with an accumulation type liquid crystal display element capable of making large-capacity display by interposing an accumulation type liquid crystal of which the anisotropy exhibits positive between a pair of base plates having a means for impressing an electric field. CONSTITUTION:An accumulation type liquid crystal 1 of which the permittivity anisotropy indicates positive is sandwiched between two sheets of glass base plates 2, 3 and a transmission type polarizing film 4 is adhered to an incident side. A semitransparent type polarizing film 5 is adhered on the opposite side and further a reflecting film 6 is adhered on the outside thereof. When the impressed voltage is on, the liquid crystal has a focal conic state and therefore the spiral axis forming a cholesteric phase is in parallel or nearly parallel with the plate 2 and since the most of the component of the incident light is scattered by the liquid crystal 1, the incident light cannot go through the polarizing film 5 and appears black. The positive display in black on the white ground is thus made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a liquid crystal display element, particularly an accumulation type liquid crystal display element having a dot matrix cell structure capable of displaying a large capacity.
The present invention relates to a liquid crystal display element capable of displaying black on a white or colored background.

BACKGROUND ART It has been proposed that a light-receiving liquid crystal display device is more suitable for displaying black on a white background than a white display on a black background, and that it is particularly easy to see without external illumination. I am desired.

Prior Art and Problems The accumulation type liquid crystal display is an effective means for inexpensive, large-capacity display using X-Y simple/matrix drive. ) Normally, this display method uses a transparent grandshuan state (Fig. 1, G) as a background, and a cloudy focal conic state (Fig. 1, G) as a background.
F) The entire display area is used, but the G:F escape factor ratio is at most 9:1, and the display contrast ratio is in principle about 1:9 at most. With this level of contrast ratio,
Black jT.

When a white negative type display is performed, visual identification is difficult unless effective illumination is provided from the outside of the display element. If a fluorescent lamp, electroluminescence, LEI, or the like is used as illumination, the advantages of liquid crystal displays such as thinness, light weight, and low power consumption are lost.

OBJECTS OF THE INVENTION The object of the present invention is to provide an accumulation-type liquid crystal display capable of displaying a large capacity in a liquid crystal display that displays a white background or a black background instead of a conventional negative type, that is, a white display on a black background. The purpose is to provide an element.

Structure of the Invention The above-mentioned object of the present invention is to provide a storage type liquid crystal having a positive dielectric constant anisotropy between a pair of substrates having an electric field applying means, and to control the transition between the Gujinjuan state and the focal conic state of this liquid crystal. A storage type liquid crystal display element using a simple X-Y matrix storage type liquid crystal display element utilizing the transition of , which is characterized in that a pair of substrates are each provided with a polarizing plate and combined.
Achieved by 扛.

Is there a reflective film on the outside of the substrate or polarizing plate in one of a pair of combinations consisting of a substrate and a polarizing plate? 1: It can be a provided element.

At least one polarizing plate or reflective film' (+-
A black positive display can be obtained on a colored background by using it in a colored manner or by selecting a shift in the polarization direction of the two polarizing plates.

For the liquid crystal and l- used in the liquid crystal display element of the present invention, the following are suitable, for example.

Cyanocyclohexane-based liquid crystal, cyanopiphenyl-based l&
Cholesteric liquid crystals, ester liquid crystals, azoxy liquid crystals, dioxysan liquid crystals, cholesteric liquid crystals, transparent conductor cholesteric liquid crystals, and ink liquid crystals.

The polarization of the two polarizing plates) Y:, the direction JL&- is selected as follows.

The polarization angle must be determined while looking at the relationship with the rotational ability of the liquid crystal, so it must be considered depending on the individual crystal composition, but in general, two polarizing plates are set at an angle of about 45°. It is desirable to put However, if you want the background color KM, you can arbitrarily rotate the angles of the two polarizing plates to select your favorite color tone.

When the applied electric field is off (well, when the liquid crystal is in the Grandshuan state), the helical axis of the liquid crystal is parallel to the original axis, so the first
41 = jf, the source that passed through the plate can pass through the liquid crystal. At this time, the polarization angle is appropriately determined by the liquid crystal, and it matches the polarization angle of the polarizing plate of fjTJ2, so the second
When the light passes through the polarizing plate of 1-0, it becomes a bright state.

When the electric field is in the open state, the liquid a6 has a claw-chalconic shape 1
As the light decreases, the original components that pass through the first polarizing plate are scattered by the liquid crystal, and the original components that pass through the second polarizing plate decrease.

Figure 1llJ2 schematically shows one embodiment of the storage type liquid crystal display element of the present invention.A storage type liquid crystal display device having a positive dielectric constant anisotropy is sandwiched between two glass substrates 2 and 3, and is placed on the incident side. A transmissive polarizing film A 4' (1: glued) has a semi-transmissive polarizing film 5 on the reflective side and a reflective film 6 on the outside thereof.However, these polarizing films 4.5 are attached to the glass substrate 2. It can also be glued to the liquid crystal side of No. 3. Polarizing films 4.5 (g) on the incident side and reflective side are used to shift the polarization direction.

Embodiment 1 As a storage type ILK product display cell schematically shown in FIG.
In addition, according to the present invention, the substrate 2 is equipped with a transmissive polarizing film!・4 (manufactured by Nitto Denko, NPF-120'5
11) Glue C on the incident side, and attach the other substrate 3G.
(manufactured by Nitto Denko, NPF-4008HP) was glued [-] to shift the polarization direction by 17° from the reflective side and by 45°.

Since the applied voltage is in the off-state v((), the z1ν product assumes a gradation state (Fig. 1, G)k, the cholesteric phase forming axis is centered on the substrate 21 (Fig. 3). a)
. When polarized light from (Ill!) enters the liquid crystal 1 in the grunge-an state, the light is rotated against the spiral rotation of the liquid crystal, and the polarization angle rotates about 45 degrees. The incident Y; is scattered and reflected by the spiral rotation.By rotating by 45 degrees, the light can pass through the second polarizing plate by being scattered and reflected, and this is reflected by the reflection film (; It was scattered and reflected brightly.

When the applied voltage is on, the f++ product takes a mechical conic state (FIG. 1, F), so the helix 11j forming the cholesteric phase is parallel or nearly parallel to the substrate 21 (the third Figure 1) Since most of the components of the incident light are scattered by the liquid crystal 1, the polarizing film 5 cannot be removed and the light appears dark. In this way, a positive display of black on a white background could be performed with a contrast ratio of 1:15 or more.

Embodiment 2 As an accumulation type liquid crystal display cell schematically shown in FIG. 2, the liquid crystal 1 illustrated above is sandwiched between two glass substrates 2 and 3. Transmissive polarizing film 4 (manufactured by Nitto Shoko, NPF-1205H)'! z
They were glued together at an intersecting angle of 45° to form a transmissive storage type liquid crystal display cell. When this was used as the source of a normal indoor fireworks lamp, a positive display with a contrast ratio of 1:15 was obtained when viewed through the light.

Example 3 Polarization direction of polarizing film 4.5 flffi 60°
Except for the above, this was carried out in the same manner as in Example 1.

The background color can be green, and the display part can be completely black.
Its contrast ratio ul:12.

Example 4 A test was carried out in the same manner as in Example 1, except that the polarizing film 4 was a blue transmission type polarizing film (NPF-1008 manufactured by Nitto Denko). In this way, it was possible to make the background black, the display part black, and the contrast ratio kl:10.

Effects of the invention According to the present invention, t'1. For example, a storage-type liquid crystal display with three advantages, such as a black-on-white positive type display and a background etc. Nazl FflX coloring public name display is i
jJ Noh.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between the applied force LL and the 90% pass rate of an accumulation type liquid crystal, and FIG. vl Figure 3 is an explanatory diagram showing the direction of the leg axis of the accumulation type j (1 item).
・Grunge-un state, ■■...Pon-1L-rohiry state, 1...--Ii ni crystal, 2, 3. ...,
:1 (I, X, 4.5...imノ"1. Board, 6
...Reflection film, a... Applied city, pressure (J
F''F', b...Applied voltage ON,... Figure 1 Applied voltage (V) Figure 2

Claims (1)

[Claims] 1. A storage 11 having a positive dielectric constant anisotropy is interposed between a pair of substrates having an electric field applying means, and a type liquid crystal is interposed between the grandshuan state and the focal conic state of this liquid crystal. In a simple X-Y matrix storage type liquid crystal display device using transition, a pair of substrates are combined with each other by providing a polarizing plate. A storage type liquid crystal display element with special characteristics. 2. In one of the pair of combinations consisting of a substrate and a polarizing plate, a reflective film is provided on the outside of the substrate or the polarizing plate. The storage type liquid crystal display element according to item 1. 3. The storage type liquid crystal display device according to claim 1 or 2, characterized in that the two biased C plates are installed with their lateral directions shifted by a predetermined angle. , a liquid crystal display element 05 according to claim 1, in which at least one polarizing plate is a fully colored polarizing plate, and claims 1 to 3, in which the reflective film is a colored reflective film.
The liquid crystal display element according to any one of Item 3. 6. During writing, the electric field between the substrates is bright in the OFF state, and the electric field between the substrates is dark in the ON state, according to any one of claims 1 to 3. storage type liquid crystal display element.