JPH06265878A - Display element - Google Patents

Abstract

PURPOSE:To make electric power consumption lower, structure simpler, production cost lower and specific visibility higher by providing a hologram reflection layer with a prescribed hologram unit and metallic layer. CONSTITUTION:This display element 1 is constituted by clamping a material 23 which is changed in refractive index or optical main axis direction by an electric field between a pair of electrodes 21 and 22 and providing the element 1 with a display part 2 disposed with a polarizing plate 24 in proximity to one electrode 21 and a hologram reflection layer 3 disposed in proximity to the other electrode 22. A so-called hologram reflection plate produced by a printing or transfer method is usable as the hologram reflection layer 3 and has the structure formed by laminating a base film 31, an anchor layer 32, a vapor deposited aluminum layer 33 as a metallic reflection layer for reflecting the light from the front surface, a coating layer 34, a hologram layer 35 and a protective layer 36 in this order. The hologram layer 35 is required to have hologram pattern units within 5nm in such a case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device which can be suitably used for a decorative display, an advertisement display body and the like.

[0002]

2. Description of the Related Art In recent years, decorative displays, such as liquid crystal displays, have been actively developed because they are lightweight, thin, and have low power consumption. As such a liquid crystal display, an invention is disclosed in which liquid crystal is interposed between polarizing plates, and a holographic mirror is interposed between a cell and a backlight to adjust the brightness according to the ambient illuminance. (JP-A-5-27226). However, since this type uses a backlight, the power consumption of the device must be large, and an inexpensive total reflection holographic mirror cannot be used, and the light of the backlight passes through. Since it was necessary to use a holographic mirror, the device as a whole was inevitably expensive.

On the other hand, a so-called reflection type liquid crystal display that does not use a backlight has low power consumption, and therefore its development is expected. As such a reflection type liquid crystal display, there is disclosed a timepiece having a display in which an electro-optical element and a hologram are arranged in proximity to each other, the incident light of the hologram is controlled by the electro-optical element, and an image reproduced on the hologram is selected. (JP-A-55-1512
issue). Further, a reflection type color liquid crystal display device having a good contrast is disclosed by providing a color filter on the front side of a scattering type element composed of liquid crystal and a dye and providing a reflecting plate on the back side thereof (JP-A-4-366925).

[0004]

However, in the display used in the former timepiece, the hologram image itself is the display content in order to see two different types of display, so the viewing angle must be changed. I have to. In order not to change the viewing angle, it is necessary to divide the area and switch it, which causes a problem that the sharpness of the display is deteriorated by the number of divisions. In addition, the latter reflective color liquid crystal display device,
Since the dye itself is used, the dye itself deteriorates rapidly, and there is a problem in durability, and since a color filter is provided, it is inevitably expensive. Furthermore, since the color tone of the whole is inevitable, it is not conspicuous and the visibility is not always satisfactory, and it is unsuitable for an advertisement display such as a signboard. The present invention has been made in view of the above-mentioned problems, and has a low power consumption, a simple structure, a low manufacturing cost, and an eye-catching, it is an object to provide a display element excellent in visibility. And

[0005]

According to the present invention, a display part in which a substance whose refractive index or optical principal axis direction changes by an electric field is sandwiched between a pair of electrodes, and a display part close to one electrode surface of the display part. Having a hologram reflection layer arranged as
In addition, there is provided a display device in which the hologram reflection layer has a hologram pattern unit having a size within 5 mm and a metal reflection layer laminated.

Further, there is provided a display element in which the display section has a polarizing plate arranged on at least one electrode surface of the display section or in the vicinity thereof.

Further, a display section in which a substance whose refractive index or optical principal axis direction is changed by an electric field is sandwiched between a pair of electrodes, and a hologram reflection layer arranged close to one electrode surface of the display section are provided. Provided is a display element, which has a hologram reflection layer and has a geometric pattern of characters, figures, symbols having a size of 5 mm or more, or a combination thereof.

Further, there is provided a display device in which the substance whose refractive index or optical principal axis direction is changed by the electric field has a thickness of 10 to 1000 μm.

Further, there is provided a display element in which the substance whose refractive index or optical principal axis direction is changed by the electric field is liquid crystal, transparent ferroelectric ceramics, polymer ferroelectrics, or a composite thereof.

The display element of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 shows one constitution of a display element of the present invention, which has one polarizing plate (constitution (1)).
It is a schematic cross-sectional view showing. FIG. 2 is a schematic cross-sectional view showing one constitution of the display element of the present invention and showing a constitution having two polarizing plates (constitution (2)). FIG. 3 is a schematic cross-sectional view showing still another constitution of the display element of the present invention and showing a constitution without a polarizing plate (constitution (3)). Hereinafter, the display element of the present invention will be described in detail for each configuration.

1. Configuration (1) In the display element 1 of the configuration (1), a substance 23 whose refractive index or optical principal axis direction is changed by an electric field is sandwiched between a pair of electrodes 21 and 22 and is close to one electrode 21. The display unit 2 is provided with a polarizing plate 24, and the hologram reflection layer 3 is provided close to the other electrode 22.

The electrodes 21, 22 are not particularly limited as long as they have transparency, and for example, ITO, N
An ESA film, a metal thin film, etc. can be used. As these electrodes, those provided on a glass plate or a plastic film can be used. Further, since a metal film such as aluminum is usually laminated on the hologram reflection layer 3 described below, this metal film may be used as an electrode on one side. The electrode pattern may be a dot-matrix display element in which stripes are formed so that arbitrary display can be performed according to a drive voltage waveform, or a segment-type display element in which electrodes are formed in a shape to be displayed.

Specific examples of the substance 23 whose refractive index or optical principal axis direction changes with an electric field include liquid crystals, transparent ferroelectric ceramics (eg PLZT), and polymer ferroelectrics (eg polyvinylidene fluoride: PVDF). , PVD
Copolymer of F with trifluoroethylene or tetrafluoroethylene: P ・ VDF _x / TrFE _100-x , P ・ VDF _X
/ TFE _100-x ). In particular, liquid crystals are preferable because the refractive index and the optical principal axis direction can be changed with a small electric field strength. The liquid crystal is not particularly limited as long as it exhibits a liquid crystal phase that responds to an electric field, such as a nematic phase or a smectic phase, but it contains a ferroelectric polymer liquid crystal because it is easy to manufacture an element and has a memory property. A ferroelectric liquid crystal composition is particularly preferable.
In this case, it is possible to impart flexibility to the entire element by sandwiching it with a plastic film with electrodes.

As the polarizing plate 24, an ordinary polarizing plate used for a liquid crystal optical element or the like can be used.

As the hologram reflection layer 3, a so-called hologram reflection plate manufactured by a printing or transfer method can be used. Any hologram pattern can be used depending on the purpose. These usually have the structure shown in FIG. That is, the base film 31, the anchor layer 32, the aluminum vapor deposition layer 33 as a metal reflection layer for reflecting the light from the upper surface, the coat layer 34, the hologram layer 35, and the protective layer are laminated in this order. There is. The hologram layer 35 uses the reflected light of the hologram layer as a background of the figure or the like displayed on the display unit, so that the appearance of the display of the figure or the like is not deteriorated by 5 mm.
It is necessary to have a hologram pattern unit within. It is also possible to use this hologram reflection plate as a substrate on one side and use a metal reflection layer such as an aluminum vapor deposition layer as an electrode on one side.

2. Configuration (2) The display element 1 of the configuration (2) is the same as the display element of the configuration (1),
In order to enable the same display even when the thickness of the substance whose refractive index or optical principal axis direction changes due to the electric field is doubled, the display unit 2 is provided with two sheets in close proximity to the pair of electrodes 21 and 22. (1) except that the orientation plates 24 and 25 of
The display element has the same structure as the display element.

3. Configuration (3) Since the display element 1 of the configuration (3) only needs to optically change the line of sight of an observer, the display unit 2 does not have an alignment plate, and therefore the schematic configuration (1) The display element has the same structure as the display element. In this case, the hologram reflecting layer 3 of the hologram reflecting layer 3 has a parallax depending on the angle.
Animals and plants of 5 mm or more to display the contents themselves,
It is necessary to have a geometric pattern consisting of figures such as objects, characters, symbols or combinations thereof. In the case of the configuration (3), as shown in FIG. 5, since the appearance of the pattern of the hologram reflection layer 3 is changed when the display element 1 is viewed obliquely, the thickness of the liquid crystal 23 is relatively small. It is preferable to make it thick, but if it is too thick, the transparency may decrease. Therefore, the thickness is preferably 10 to 1000 μm.

[0018]

The operation of the display device of the present invention will be described below. 1. In the case of the configurations (1) and (2), the intensity of the reflected light can be turned on / off or modulated by the birefringence effect by changing the electric field as in a normal liquid crystal display element. In this case, a normal reflection plate has a small change in color and a change in contrast depending on the viewing angle, but by using the hologram reflection layer, the reflection angle can set the color tone with a high degree of freedom, and the visibility is high, A conspicuous display body can be provided.

2. In the case of the configuration (3) Since the substance 23 whose refractive index and the like change according to the electric field is used, the apparent optical paths are (1) and (2) as shown in FIG.
Varies between. Although the reflection pattern and color tone of a normal hologram reflection plate change depending on the viewing angle, the display element of the present invention can change the display content (hologram reflection light) without the observer moving. In this case, the thicker the layer in which the refractive index changes is (10 to 1000 μm).
m) The parallax can be increased.

[0020]

EXAMPLES The present invention will be described in more detail below with reference to examples. Example 1 A mixture of a ferroelectric polymer liquid crystal having a structure represented by the following formula and a polystyrene resin (molecular weight: 52000) in a weight ratio of 97: 3 was used as a 25% by weight MEK (methyl ethyl ketone) solution, which was previously formed into stripes by a microgravure coater. PES substrate with etched ITO electrode (polyethersulfone: Sumitomo Bakelite Co., Sumilite FST,
It was applied on an electrode surface having a thickness of 100 μm, a width of 150 mm and a length of 1000 mm). Immediately after the solvent was dried, a pair of rubber rolls was used to laminate the same type of substrate on which nothing was coated. Next, while applying a direct current of 60 V between the upper and lower electrodes at room temperature, flexural deformation was applied to the whole several times for horizontal alignment treatment. A part of the film was sandwiched between crossed polarizers, and the film thickness was determined by measuring the spectrum of transmitted light. Next, two polarizing plates cut out with the polarization axis tilted at 20 ° from the longitudinal direction are arranged one above the other (paranicols arrangement),
Further, a hologram sheet (# 204 manufactured by Murata Gold Leaf Co., Ltd.) was placed under the lower polarizing plate to complete the device. When a rectangular wave voltage of ± 5 V and 1 Hz was applied between the upper and lower electrodes, it was possible to obtain an eye-catching and highly visible display which could not be considered as a reflective display element.

[0021]

[Chemical 1]

Example 2 A 5 cm square glass substrate with ITO (thickness 0.8 mm) was coated with polyimide (Semicofine S, manufactured by Toray Industries, Inc.).
P-710) was spin-coated, baked at 200 ° C. for 1 hour, and then strongly rubbed in one direction with a cloth for rubbing treatment.
Then, the upper and lower substrates were attached to each other with an epoxy adhesive in the peripheral portion so that the cell thickness was 0.5 mm so that the rubbing directions were the same. Then, from one of the injection ports opened in two places, a nematic liquid crystal (manufactured by Chisso Corporation, CS-10
13) was injected capillarity. After sealing the injection ports on both sides with an epoxy adhesive, a hologram sheet (# 262 manufactured by Murata Gold Leaf Co., Ltd.) was attached to the lower glass plate. 45 °
While looking from a diagonal direction, 1 kHz between the upper and lower electrodes, 10
When the AC voltage of V was turned on and off, the pattern provided on the hologram sheet seemed to change apparently. In this case, it was not necessary to change the viewing angle.

[0023]

The display device of the present invention has low power consumption, a simple structure, a low manufacturing cost, and is excellent in visibility and visibility. Further, the display content (hologram reflected light) can be changed without changing the viewing angle of the observer.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing one constitution of a display element of the present invention and showing a constitution having one polarizing plate (constitution (1)).

FIG. 2 is a schematic cross-sectional view showing another configuration of the display element of the present invention and showing a configuration having two polarizing plates (configuration (2)).

FIG. 3 is a schematic cross-sectional view showing still another configuration of the display element of the present invention and showing a configuration without a polarizing plate (configuration (3)).

FIG. 4 is a schematic cross-sectional view showing the structure of a hologram reflection layer.

FIG. 5 is a schematic sectional view showing an optical path in the case of the configuration (3).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Display element 2 ... Display part 21, 22 ... Electrode 23 ... Substance whose refractive index or an optical principal axis direction changes with an electric field 24, 25 ... Polarizing plate 3 ... Hologram reflective layer

Claims (5)

[Claims] 1. A display section in which a substance whose refractive index or optical principal axis direction is changed by an electric field is sandwiched between a pair of electrodes, and a hologram reflection layer arranged close to one electrode surface of the display section. And the hologram reflection layer has
Hologram pattern unit within 5 mm, and
A display element comprising a metal reflective layer laminated. 2. The display element according to claim 1, wherein the display section has a polarizing plate disposed on or near at least one of the electrode surfaces of the display section. 3. A display section, in which a substance whose refractive index or optical principal axis direction is changed by an electric field is sandwiched between a pair of electrodes, and a hologram reflection layer arranged close to one electrode surface of the display section. And having the hologram reflection layer,
A display device having a geometric pattern consisting of characters, figures, symbols or a combination thereof having a size of 5 mm or more. 4. The display element according to claim 3, wherein the substance whose refractive index or the optical principal axis direction is changed by the electric field has a thickness of 10 to 1000 μm. 5. The substance whose refractive index or optical principal axis direction is changed by the electric field is liquid crystal, transparent ferroelectric ceramics, polymer ferroelectrics, or a composite thereof. The display element according to any one of 1 to 4.