JP2000066185A - Liquid crystal display - Google Patents

Abstract

(57) [Summary] A liquid crystal display which can be used as a mirror as well as an image display device, and which can be used regardless of ambient illuminance because a light emitting means is attached to a front surface or a side surface. Provide equipment. SOLUTION: Upper and lower substrates 22 and 23 which are separated from each other by a predetermined distance to form a liquid crystal sealed space;
23, transparent electrode layers 24, 25 formed in a predetermined pattern on the mutually facing surfaces, and upper and lower substrates 22, 23, on which the transparent electrode layers 24, 25 are formed, respectively formed on the mutually facing surfaces. Films 26, 27 for vertically aligning
And a network type liquid crystal 29 sealed in the liquid crystal sealed space, and a reflection film 28 provided on the lower substrate 23 and reflecting incident light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of embodying an image and usable as a mirror.

[0002]

2. Description of the Related Art A liquid crystal display device is a light receiving element for displaying an image using light from the outside, consumes less power than other devices, and has various sizes from ultra-small to large. In addition to the above, there is an advantage in that various video display patterns can be obtained in addition to the fact that it can be manufactured. Therefore, the liquid crystal display device is positioned as extremely important in the display device field.

FIG. 4 shows an example of a liquid crystal display device having the above advantages. As shown, the liquid crystal display device includes upper and lower substrates 1 provided so as to face each other.
1, 11 'and upper and lower electrodes 12, 12' and upper and lower alignment films 13, 13 'between mutually facing surfaces of the substrates 11, 11'.
And a structure in which the liquid crystal 14 is interposed. Upper and lower electrodes 1
2, 12 'are upper and lower substrates 1 in a predetermined matrix.
1, 11 'are formed on each opposing surface. Orientation films 13, 13 'are formed on the opposing surfaces of the upper and lower substrates 11, 11' on which the upper and lower electrodes 12, 12 'are formed so as to cover the electrodes, respectively. Liquid crystal 14 is sealed between the alignment films 13 and 13 '. In the liquid crystal display device configured as described above, a polarizing plate (not shown) is selectively provided on the upper and lower surfaces of the upper and lower substrates 11 and 11 ′. A reflection plate is provided on the lower surface side of the substrate 11 '.

In the conventional liquid crystal display device configured as described above, the liquid crystal is oriented by applying a predetermined voltage to the selected upper and lower electrodes 12, 12 ', thereby forming an image.

However, the conventional liquid crystal display device has only a function of displaying an image, and research for adding a new function has been continuously made in order to secure competitiveness as a product.

As one example, there has been developed a liquid crystal display element having the function of a liquid crystal display element and exhibiting a mirror-like effect when turned off. However, there are many restrictions on providing a liquid crystal display element with a mirror-like effect as described above due to the pattern between the electrodes and the use of a polarizer.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal display device having an image display function and usable as a mirror. It is in.

Another object of the present invention is to provide a liquid crystal display device which can improve the brightness of an image and can be used without using external light.

[0009]

In order to achieve the above object, a liquid crystal display device according to the present invention comprises: an upper and lower substrate forming a liquid crystal enclosing space separated by a predetermined distance; A transparent electrode layer formed on the surface in a predetermined pattern; and an alignment film formed on each of the opposing surfaces of the upper and lower substrates on which the transparent electrode layer is formed, for vertically aligning liquid crystal molecules, and the liquid crystal. It is characterized by comprising a network type liquid crystal sealed in the sealing space, and a reflection film provided on the lower substrate and reflecting incident light.

[0010] In the present invention, the reflection film may be formed on the lower substrate by at least one of gold, copper, platinum and nickel.
One is coated and formed. The image display apparatus further includes a light irradiating unit provided on the side adjacent to the upper substrate and irradiating light to the effective screen side.

Further, in order to achieve the above object, another liquid crystal display device according to the present invention is characterized in that an upper and lower substrate forming a liquid crystal enclosing space separated by a predetermined distance and a mutually opposing surface of the upper and lower substrate. A transparent electrode layer formed in a predetermined pattern, an alignment film formed on each of the opposing surfaces of the upper and lower substrates on which the transparent electrode layer is formed, for vertically aligning liquid crystal molecules, and the liquid crystal enclosing space. And a reflection type liquid crystal provided on the lower substrate and reflecting incident light.

The above-mentioned polymer liquid crystal is obtained by putting liquid crystal in a polymer and making it spherical. The reflection film is formed by coating at least one of gold, copper, platinum, and nickel on a lower substrate. The image display apparatus further includes a light irradiating unit provided on the side adjacent to the upper substrate and irradiating light to the effective screen side.

[0013]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a preferred embodiment of the liquid crystal display device according to the present invention. Referring to FIG. 1, the liquid crystal display device according to the present invention has an image display function and can be used as a mirror.

As shown in the figure, the liquid crystal display devices are connected to each other, and upper and lower substrates 22, 23 having a liquid crystal layer interposed therebetween.
And a predetermined pattern of transparent electrode layers 24 and 25 formed on inner surfaces of the upper and lower substrates 22 and 23 facing each other. The transparent electrode layers 24 and 25 can be formed in a matrix.

When no potential is applied to the transparent electrode layers 24 and 25, liquid crystal molecules to be described later are vertically applied to the inner surfaces of the upper and lower substrates 22 and 23 on which the transparent electrode layers 24 and 25 are formed. The alignment films 26 and 27 to be arranged are formed. Further, in a space 21 in which the liquid crystal layer is interposed, a network-like liquid crystal (polymer network liquid crystal;
NLC) 29 is enclosed. This network-like liquid crystal 29
After wrapping the liquid crystal substance with a polymer to form a spherical mass,
An anisotropy of dielectric constant (di
electric anisotropy) Δε has a value smaller than 0.

The lower substrate 23 is provided with a reflection film 28 for reflecting incident light. The reflection film can be formed by coating gold, copper, platinum, nickel, or the like on the upper surface side of the lower substrate 23 which is the lower surface of the transparent electrode layer 25 and the alignment film 27. In this case, the reflection film 28 is transparent. Since it is necessary to be insulated from the electrode layer 25 and the alignment film 27, it is desirable to form a transparent insulating film between them. The reflection film 28 may be formed on the lower surface of the lower substrate 23. At this time, the reflection film is separately manufactured and attached to the lower surface side of the lower substrate 23.

The upper and lower substrates 22 and 23 joined to each other.
A separate light irradiating means 40 is provided on an upper portion or a side surface adjacent to. As the light irradiating means 40, any means can be used as long as it can irradiate light on an effective screen formed by aligning liquid crystals. For example, a fluorescent lamp or the like is used.

FIG. 2 shows another embodiment of the liquid crystal display device according to the present invention. Here, the same reference numerals are given to the same components as those in the above embodiment.

As shown in the figure, in a state where transparent electrode layers 24 and 25 are formed on opposing surfaces of upper and lower substrates 22 and 23,
A droplet-shaped liquid crystal (PDLCD) 31 is sealed in the space 21 in which the liquid crystal layer is interposed. The droplet-shaped liquid crystal 31 is a liquid crystal material wrapped in a polymer to form a spherical liquid crystal mass, and has a dielectric anisotropy Δε smaller or larger than zero. On the lower substrate 23, a reflection film 28 for reflecting incident light is formed in the same manner as in the embodiment.

The operation of the liquid crystal display device according to the present invention thus configured will be described.

First, in order to display an image using the liquid crystal display device according to the present invention, transparent electrode layers 24, 2 formed on mutually opposing surfaces of the upper substrate 22 and the lower substrate 23 are formed.
5, a predetermined voltage is applied to one of the electrodes.

Thus, the liquid crystal, ie, the liquid crystal molecules of the network-like liquid crystal 29 or the droplet-like liquid crystal 31 are scattered to block light, and the portions where no voltage is applied are vertically oriented by the alignment films 26 and 27. By being oriented, external light is reflected on the entire surface by the reflection film 28.
Therefore, an image is formed by a portion where light is scattered by the liquid crystal molecules and a portion where the light passes. In the process of forming an image as described above, when the surroundings are dark and the amount of light for forming an image is not sufficient, the fluorescent lamp is caused to emit light so that the surroundings formed on the effective screen are sufficiently bright.

When the liquid crystal display is not driven, the liquid crystal molecules of the network liquid crystal 29 or the droplet liquid crystal 31 are vertically aligned by the alignment films 26 and 27. Accordingly, as shown in FIG. 3, the light is incident through the liquid crystal molecules, and then is totally reflected through the reflective film 28. In this process, the liquid crystal molecules have a dielectric anisotropy Δε smaller or larger than 0. When the dielectric anisotropy Δε of the liquid crystal molecules is larger than 0 (Δε> 0), the liquid crystal molecules are oriented in the direction of the electric field, whereas the dielectric anisotropy Δε of the liquid crystal molecules is smaller than 0. In the case (Δε <0), it is oriented in the vertical direction of the electric field. Therefore, when an electric field is applied to the liquid crystal, the liquid crystal molecules having a dielectric anisotropy greater than 0 (Δε> 0) have their normal refractive index n _o depending on the orientation.
The value is equal to the refractive index n of the polymer, total reflection occurs without light absorption, and the liquid crystal molecules (Δε
<0), the extraordinary refractive index of itself by the orientation in the vertical direction of the electric field (extra-ordinary refractive index) n e is equal to the refractive index n of the polymer, the total reflection without optical absorption occurs. Since the liquid crystal molecules having a dielectric anisotropy Δε smaller than 0 are superior to the liquid crystal molecules having a dielectric anisotropy Δε larger than 0, liquid crystal molecules satisfying Δε <0 are widely used.

[0025] Here, ordinary index n _o and the extraordinary refractive index n _e
This section of the specification divided refractive index that determines the optical characteristics in accordance with the anisotropic quality of the liquid crystal into two vector components, ordinary refractive index of the vector component with a constant fixed value regardless of the direction n _o, A vector component having a value that varies according to the direction is called an extraordinary refractive index _ne . The reflection film 28 is made of gold,
Since it is formed by coating with copper, platinum, nickel or the like, it can be used as a mirror.

[0026]

As described above, the liquid crystal display device according to the present invention can be used not only as an image display device but also as a mirror. Further, since the light emitting means is attached to the front surface or the side surface, it can be used regardless of the surrounding illuminance.

Although the present invention has been described with reference to an embodiment shown in the drawings, this is merely illustrative and will be within the scope of the present invention. It is needless to say that the present invention can be modified into various embodiments.

[Brief description of the drawings]

FIG. 1 is a sectional view of a liquid crystal display device according to the present invention.

FIG. 2 is a sectional view showing another embodiment of the liquid crystal display device according to the present invention.

FIG. 3 is a view illustrating a reflection state of light when the liquid crystal display device according to the present invention is used as a mirror.

FIG. 4 is a sectional view of a conventional liquid crystal display device.

[Explanation of symbols]

 Reference Signs List 21 Space where liquid crystal layer is interposed 22, 23 Upper and lower substrates 24, 25 Transparent electrode layer 26, 27 Alignment film 28 Reflection film 29 Network liquid crystal 40 Light irradiation means

Claims (8)

[Claims] An upper and lower substrate forming a liquid crystal enclosing space separated by a predetermined distance; a transparent electrode layer formed in a predetermined pattern on mutually facing surfaces of the upper and lower substrates; and a transparent electrode layer formed thereon. An alignment film formed on each of the opposing surfaces of the upper and lower substrates for vertically aligning liquid crystal molecules; a network-type liquid crystal sealed in the liquid crystal sealing space; A liquid crystal display device, comprising: a reflection film that reflects reflected light. 2. The liquid crystal display device according to claim 1, wherein the dielectric anisotropy of the liquid crystal is smaller or larger than zero. 3. The liquid crystal display device according to claim 1, wherein the reflection film is formed by coating at least one of gold, copper, platinum, and nickel on a lower substrate. 4. The liquid crystal display device according to claim 1, further comprising light irradiating means provided on a side adjacent to the upper substrate and irradiating light to the upper substrate side. 5. An upper and lower substrate separated by a predetermined distance to form a liquid crystal enclosing space, a transparent electrode layer formed in a predetermined pattern on mutually facing surfaces of the upper and lower substrates, and the transparent electrode layer is formed. An alignment film formed on each of the opposing surfaces of the upper and lower substrates for vertically aligning liquid crystal molecules, a droplet-type liquid crystal sealed in the liquid crystal sealing space, and provided on the lower substrate, A liquid crystal display device, comprising: a reflection film that reflects incident light. 6. The liquid crystal display device according to claim 5, wherein the dielectric anisotropy of the liquid crystal is smaller or larger than zero. 7. The liquid crystal display device according to claim 5, wherein the reflection film is formed by coating at least one of gold, copper, platinum, and nickel on a lower substrate. 8. The liquid crystal display device according to claim 5, further comprising light irradiating means provided on a side adjacent to the upper substrate and irradiating light to the upper substrate side.