JPH03116118A - Ferroelectric liquid crystal panel - Google Patents

Abstract

PURPOSE:To simultaneously perform the emission of light and the generation of sound with a ferroelectric liq. crystal panel when voltage is impressed by dispersing particles emitting light in an electric field in a ferroelectric liq. crystal sealed in the gap between substrates. CONSTITUTION:A pair of transparent substrates 1a, 1b are placed so that oriented films 4a, 4b confront each other with a certain gap in-between, a ferroelectric liq. crystal 6 is sealed in the gap and the substrates 1a, 1b are sealed with a sealant 5. The liq. crystal 6 contains dispersed particles 7 of zinc sulfide, etc., emitting light in an electric field. The oriented films 4a, 4b have been oriented by rubbing or other method and the liq. crystal 6 sealed in the gap between the films 4a, 4b is in a homogeneously oriented state. When AC voltage is impressed between both transparent electrodes 2a, 2b of the resulting ferroelectric liq. crystal panel, the entire panel vibrates by the electrostriction of the liq. crystal 6 and sound is generated according to the frequency of the impressed voltage. When the voltage is impressed, the particles 7 in the liq. crystal 6 emit light. The emission of light and the generation of sound can be simultaneously performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a ferroelectric liquid crystal panel that can emit light as well as sound.

[Prior Art] The present applicant has proposed a piezoelectric element using ferroelectric liquid crystal and a conversion device using this piezoelectric element in Japanese Patent Application No. 63-217690. The sound pressure characteristics of this example were measured, and it was confirmed that it had a sound generation function.

Furthermore, the present applicant has proposed an electroluminescent device with sound generation function (hereinafter referred to as rE
It is called "L device". ) is proposed. This device uses a ferroelectric liquid crystal panel as a sounding device, and EL elements are laminated on the back surface of the device to provide a light emitting function.

Furthermore, there are two types of EL devices used as light-emitting devices: a dispersion type (thick film type) and a thin film type. It was something.

[Question to be solved 2i1 In such a conventional device, the light emitting device and the sounding device are simply stacked on top of each other, and each has a separate structure, so the structure is complex and it is difficult to make it smaller and thinner. Moreover, the cost was high.

Therefore, an object of the present invention is to provide a ferroelectric liquid crystal panel itself with a light emitting function.

[Means for Solving the Problems] In order to achieve the above object, the ferroelectric liquid crystal panel of the present invention comprises a pair of substrates facing each other at a constant interval and having electrodes on each opposing surface, and It comprises an alignment layer provided on at least one opposing surface of the split plate, a ferroelectric liquid crystal sealed between both substrates, and electroluminescent particles mixed and dispersed in the ferroelectric liquid crystal. At least one of the substrates is a transparent substrate, and the electrode provided on the transparent substrate is a transparent electrode.

[Function] When applied to the electrodes of the ferroelectric liquid crystal panel according to the present invention,
Sound is generated by the electrostrictive effect of ferroelectric liquid crystal.

Further, by applying this voltage, the electroluminescent particles mixed and dispersed in the ferroelectric liquid crystal emit light.

[Example] Embodiments of the present invention will be described below based on the drawings.

As shown in FIG. 1, a transparent electrode 2a made of ITO or the like is formed on one substrate la made of transparent glass or the like by a method such as vapor deposition. Then, on the transparent electrode 2a, S
A transparent insulating layer 3a such as io 2 and an alignment film 4a such as polyimide are laminated.

The same is true for the other substrate, and a transparent insulating film 3b such as SiO2 and an alignment film 4b such as polyimide are laminated on a transparent electrode 2b made of ITO or the like provided on a glass substrate 1b.

Next, the pair of substrates 1a and Ib are arranged so that the alignment films 4a and 4b face each other with a certain gap between them, a ferroelectric liquid crystal 6 is sealed in the gap between both alignment films, and a sealing material 5 It is sealed by. ZLI-37 as ferroelectric liquid crystal 6
74 (manufactured by Merck & Co.), etc., and electroluminescent particles 7 such as zinc sulfide (ZnS) are mixed and dispersed in advance.

Further, the alignment films 4a and 4b are subjected to an alignment treatment such as rubbing, and the ferroelectric liquid crystal 6 sealed in the gap therebetween is in a homogeneous alignment state.

Picture electrode 2 of the ferroelectric liquid crystal panel configured as described above.
When an alternating voltage is applied between a and 2b, the entire panel vibrates due to the electrostrictive action of the ferroelectric liquid crystal 6, producing sound according to the frequency of the applied voltage. Further, when an alternating current voltage is applied, the electroluminescent particles 7 in the ferroelectric liquid crystal 6 emit light.

The sound pressure level of sound generation and the brightness of light emission vary depending on the applied voltage frequency. The graph shown in FIG. 2 shows that when a voltage is applied to the panel having the above-mentioned configuration and the frequency of this voltage is changed, the front 1. It shows the results of measuring the sound pressure level at a position of 5 cm. According to this, the sound pressure level is low at about 65 to 70 dB up to a frequency of about 600 Hz, and rises rapidly at frequencies higher than 600 Hz.
It reaches a maximum value of 90 dB or more at about Hz, and gradually decreases above 10 KHz. The luminance increases gradually up to about 200Hz, but from about 200Hz to
In the 2KHz range, it is stable at about 30 c d/tolerance, and 3
The maximum value is about 40cd/rr at about KHz? , and then decreases rapidly. Therefore, the applied voltage frequency is 2 to 3
By setting the frequency to about KHz, light emission and sound generation can be performed simultaneously.

Note that since the sound pressure level and brightness curves are shifted, it is also possible to perform only one of them by selecting the frequency. For example, by applying a voltage of 500 Hz, only light emission can be caused, and at a frequency of 10 to 20 KHz.
By applying a voltage of , it is possible to cause only sound to be produced.

By selecting the frequency of the applied AC voltage according to the sound generation/light emission characteristics in this manner, it is possible to perform either one or both functions simultaneously, or to control the degree of sound generation/light emission.

If this panel is used as an alarm clock or a warning light inside a car, it will be effective in alerting people with both light emission and sound.Especially in dark places or at night, simultaneous messages using light and sound will be possible. Since the light source and sound source are the same, it is easy to confirm the message location.

In the above embodiment, both the picture electrodes 2a and 2b are transparent electrodes, but one of the electrodes may be a metal electrode and an opaque electrode. For example, when the electrode 2b is a metal electrode, the light emitted from the luminescent particles 7 is reflected by the metal electrode 2b, passes through the substrate 1a, and is emitted only in an upward direction, thereby increasing the amount of light. Further, the electrode 2b is a transparent electrode, and the substrate 1
A similar effect can be obtained by using an opaque substrate as b and allowing the substrate to reflect light. Note that electrode 2
By using a metal electrode b and making this electrode thick, the substrate can be omitted and can be used both as an electrode and a substrate. In this case, it is preferable to coat the surface for electrical insulation.

Further, in the above embodiment, the alignment film 4 is provided on both the substrates 1a and lb.
Although the alignment films a and 4b are provided, the alignment film may be provided on either one of the substrates. Although the insulating layer is also provided on both substrates 1a and lb, the insulating layer may be provided on only one substrate.
Further, if the alignment film is insulating, the insulating layer may be omitted.

[Effects] In the present invention, electroluminescent particles are mixed and dispersed in the ferroelectric liquid crystal sealed between the substrates, so that the ferroelectric liquid crystal panel itself can simultaneously emit light and generate sound by applying a voltage. be able to.

Further, by changing the applied voltage frequency, the degree of light emission and sound generation can be changed, and only one of the functions can be performed, so that various uses can be made depending on the purpose.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a ferroelectric liquid crystal panel according to an embodiment of the present invention, and FIG. 2 is a graph showing the relationship between applied voltage frequency, sound pressure level, and luminance. la, lb... Transparent substrate, 2a, 2b... Transparent electrode, 4a, 4b... Alignment film, 5... Seal material, 6... Ferroelectric liquid crystal, 7... Electroluminescent particles. that's all

Claims (1)

[Scope of Claims] A pair of substrates facing each other at a constant interval and having electrodes on each opposing surface; an alignment layer provided on the opposing surface of at least one of the substrates; The device includes a ferroelectric liquid crystal sealed between substrates, and electroluminescent particles mixed and dispersed in the ferroelectric liquid crystal, and at least one of the substrates is a transparent substrate, and the transparent A ferroelectric liquid crystal panel characterized in that electrodes provided on a substrate are transparent electrodes.