JPH082657Y2 - Particle-dispersed display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a particle dispersion type display device.

[Prior Art] In a particle dispersion type display device, a dispersion liquid layer in which needle-shaped or plate-shaped light-absorbing dispersed particles are dispersed in a transparent dispersion medium is formed on a pair of transparent substrates provided with transparent electrode layers. It is to be enclosed in a cell constituted by sandwiching.

When no voltage is applied to the transparent electrode layer, the dispersed particles are oriented in an arbitrary direction due to Brownian motion, so that incident light is absorbed or scattered by the dispersed particles, and the display element does not transmit light. However, when a voltage is applied to the transparent electrode layer, the dispersed particles are polarized and arranged in the direction of the electric field, so that the absorption cross section for light is drastically reduced and the display element transmits light.

As described above, since the particle-dispersed rotary type display element can display two colors, it can be used not only as a display but also as a window for vehicles because it can block or transmit incident light. Can also be considered.

[Problems to be Solved by the Invention] When this particle-dispersed display device is used as a window for a vehicle, the light is directed in a certain direction in order to limit the brightness of incident light and reduce glare depending on the part of the window. There is a case where it is desired to add gradation to the transparent state of, so-called blurring. However, in the particle-dispersed display element that has been conventionally used, an electric field is applied to the entire cell when a voltage is applied, and therefore it is not possible to create a blurring state in which the transmission of light of the display element has a gradation.

The present invention was devised to solve the problem that blur cannot be applied when a particle-dispersed display device is used in a window of a vehicle or the like. It is an object of the present invention to provide a particle-dispersed display device capable of providing a so-called blur state in which the transmission state changes stepwise.

[Means for Solving the Problems] The particle-dispersed display device of the present invention comprises: transparent substrates arranged to face each other; transparent electrode layers respectively formed on opposite faces of the transparent substrate; A spacer provided to form a cell between the substrates, a highly insulating transparent dispersion medium enclosed in the cell, and a needle-shaped or plate-shaped light-absorbing dispersion dispersed in the dispersion medium. In a particle-dispersed display element including particles, at least one of the transparent electrode layers is provided with an electrode void whose area gradually increases in any direction.

The transparent substrate used in the particle-dispersed display device of the present invention may be a glass substrate or a resin substrate. The transparent substrate may be slightly colored as long as it has a light transmitting property.

The spacer is interposed between the transparent substrates to form a cell by keeping a predetermined space between the transparent substrates, and the dispersion medium and the dispersed particles are enclosed in the cell.

As the material of the transparent electrode, various transparent conductive materials can be used, but ITO (indium-tin-oxide), tin dioxide or the like is usually used. The method for forming the transparent electrode can be any of various vapor deposition methods, or a sputtering or spray-firing method.

As the dispersed particles, needle-like metal powder such as chromium, needle-like crystals of herapatite or needle-like crystals of periodate of dihydrocinchonidine sulphate, etc. are used, but when these particles are aligned in a certain direction. , A crystal having a high light transmittance, that is, a needle-shaped, rod-shaped, flaky or flaky crystal.

The shape of the electrode voids provided on at least one of the transparent electrode layers may be a stripe shape or a circular shape, and may be any shape. The point is that the electrode gap may have a gradually increasing area in the direction in which blurring is provided (for example, in the peripheral edge direction). Further, the electrode gap provided in the transparent electrode layer may be provided not only in one of the transparent electrode layers but also in both. In that case, the shapes and sizes of the electrode voids do not necessarily have to be symmetrical, and the voids may be staggered.

[Operation] When no voltage is applied between the transparent electrode layers, the dispersed particles are oriented in an arbitrary direction due to Brownian motion, so that the incident light is absorbed or scattered by the dispersed particles, and the display element is in a light-shielded state. The color of the dispersed particles is displayed.

When a voltage is applied between the transparent electrode layers, the acicular, rod-shaped, or flaky dispersed particles are polarized and aligned in the direction of the electric field, so that incident light passes between the dispersed particles, so the display element transmits light. It becomes a state. At this time, in the portion where the electrode void having the area gradually increasing in any direction is provided, the dispersed particles are not arranged in the electric field direction only in the electrode void portion, and the light-shielding portion gradually increases in that direction. A lot remains in
You can display blur.

[Embodiment] A preferred embodiment of the present invention will be described below with reference to the drawings. The present invention should not be construed as being limited to the description of the embodiments below.

FIG. 1 is a sectional view of an embodiment of the present invention, and FIGS. 2 (a) and 2 (b) are sectional views for explaining the operation of the embodiment of FIG.

In FIG. 1, the two transparent substrates 1a and 1b have a thickness of 1.
1 mm soda lime glass (made by Asahi Glass Co., Ltd.), two of which are arranged so as to face each other with a desired gap, and cells are formed between the substrates on the inner surfaces of the peripheral portions of the transparent substrates 1a and 1b. Therefore, the spacer 5 made of a 100 μm thick polyester film (manufactured by Toray Industries, Inc.) is fixed. An adhesive 6 made of an epoxy adhesive is adhered to the outer periphery of the spacer 5 and the transparent substrates 1a and 1b.

On the surfaces of the transparent substrates 1a and 1b facing each other,
Transparent electrode layers 2a and 2b made of ITO are formed with a thickness of 1500Å. The transparent electrode layer 2a on the incident light side is formed on the entire surface of the transparent substrate 1a, but on the transparent electrode layer 2b on the transmitted light side, the stripe-shaped electrode gaps 7 are gradually narrowed from the end of the display portion. Is provided and is patterned by screen printing and etching techniques. In addition, Table 1 shows the positions from the end of the display portion and the widths of the transparent electrode layer 2b and the electrode gap 7. Therefore, in this embodiment, it is possible to insert blurring up to 240 mm from the end of the display section.

Subsequently, in the cell, a dispersion medium 4 in which dispersed particles 3 are dispersed
Was enclosed. A periodate of dihydrocinchonidine sulfate was used as the dispersed particles, and paracresyl acetate was used as the dispersion medium 4.

Next, the operation of the apparatus of this embodiment will be described with reference to FIGS. 2 (a), 2 (b), 3 (a) and 3 (b).

When a voltage is not applied between the transparent electrode layers 2a-2b, as shown in the partial enlarged view of the arrangement of the dispersed particles 3 in the light-shielded state of FIG. Since the light is directed in an arbitrary direction by the Brownian motion, the incident light is absorbed or scattered by the dispersed particles 3, the display element is in a light shielding state, and the color of the dispersed particles 3 is displayed.

When a voltage is applied between the transparent electrode layers 2a-2b, the dispersed particles 3 are polarized in the longitudinal direction as shown in a partially enlarged view showing the arrangement of the dispersed particles in the transmission state in FIG. Since the incident light passes between the dispersed particles 3 due to the arrangement of the display elements, the display element is in a light transmitting state. However, since the transparent electrode layer 2b on the transmitted light side is provided with the electrode voids 7 ... whose area gradually increases toward the peripheral edge, an electric field is not generated in the lacked portion of the electrode layer. Instead, only that portion has a light-shielding portion 3b in a stripe shape. Therefore, the amount of transmitted light gradually decreases toward the upper end portion, so that blur display can be performed.

In this embodiment, the electrode voids 7 have a stripe shape, but as shown in the partial plan view of the transparent electrode layer 2b in FIG. The effect is obtained. In addition, as shown in the partial cross-sectional view of FIG. 5, the electrode gap 7 is formed on both transparent electrode layers 2a and 2b.
They may be provided so that they are staggered. Thus, when the transparent electrode layers 2a and the void electrodes 7 of the 2a are staggered,
Since the light-shielding portion when the voltage is applied is formed obliquely, smoother blurring can be obtained.

[Advantage of the Invention] As described in detail above, the particle-dispersed display device of the present invention has a light-absorbing property in a cell formed between a pair of transparent substrates provided with transparent electrode layers on opposite surfaces. In a particle dispersion type display element in which a dispersion medium in which dispersed particles composed of needle crystals are dispersed is provided, at least one of transparent electrode layers is provided with an electrode void whose area gradually increases in either direction. In the light transmission state of the display element by applying a voltage, the dispersed particles are not arranged in the electric field direction only in the electrode void portion, and the light-shielding portion is gradually stepped in the above direction. Since much remains, blurring can be displayed.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIGS. 2 (a) and 2 (b) are sectional views for explaining the operation of the embodiment of FIG. 1, and FIG. FIG. 3B is a partially enlarged view showing the arrangement of dispersed particles in a transparent state, FIG. 3B is a partially enlarged view showing the arrangement of dispersed particles in a transparent state, and FIG. 4 is a plan view of a transparent electrode layer of another embodiment. The drawing is a partial sectional view of another embodiment. 1a and 1b ... transparent substrate, 2a and 2b ... transparent electrode layer,
3 ... Dispersed particles, 4 ... Dispersion medium, 5 ... Spacer, 6 ...
… Adhesive, 7… Electrode void

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Tatsuta Adult, Nagakute-cho, Aichi-gun, Aichi-gun, large-scale character, Yokomichi 41-1 Inside Toyota Central Research Laboratory, Inc. (72) Miji Hirose, Aichi-gun, Nagakute-machi, Aichi-gun, large character Yokomichi 41-1 Toyota Central Research Institute Co., Ltd. (72) Creator Usuki Arimitsu Aichi-gun Aichi-gun Nagakute-machi Oocho Nagayoko Yokomichi 41-1 Toyota Central Research Institute Co., Ltd. (56) Reference JP-A-1-126629 (JP) , A) Actual development Sho 62-19631 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A transparent substrate arranged to face each other, transparent electrode layers respectively formed on opposite faces of the transparent substrate, and a spacer provided to form a cell between the transparent substrates. A particle-dispersed display element comprising a highly insulating transparent dispersion medium enclosed in the cell, and needle-shaped or plate-shaped light-absorbing dispersed particles dispersed in the dispersion medium, wherein the transparent electrode A particle-dispersed display element, characterized in that at least one of the layers is provided with an electrode void whose area gradually increases in either direction.