JPH0720421A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To transmit and receive necessary data from the display of a computer by using the transparent electrode of a glass substrate with the transparent electrode for the liquid crystal display element as an antenna for radio communication. CONSTITUTION:Glass substrates 1 and 2 are arranged having their surfaces, where conductive films 3 and 4 are formed, opposite each other and liquid crystal 5 is sandwiched between them. When the conductive films 3 and 4 are set opposite each other, 480X604 matrix patterns are formed as electrodes for driving the liquid crystal and a specific driving voltage is selectively applied to the matrix electrodes. Further, an impedance matching circuit element 9 is coupled with the conductive film 3 for operation as the antenna for radio communication, and the impedance matching circuit element 9 is connected to the computer 10 in which a radio transmitter is incorporated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device capable of wireless communication.

[0002]

2. Description of the Related Art Conventionally, miniaturization of computers has been actively proposed in pursuit of convenience of personal computers. In particular, in order to miniaturize a computer to make it portable, a liquid crystal display element is often used as a display for operating the computer. Further, in order to output and record the calculation results executed by the computer to the outside, it is necessary to connect the computer and the printing device with a predetermined dedicated cable. In recent years, it has been proposed to transmit a predetermined signal from a computer to a printing device by wireless communication without using the dedicated cable in order to share one printing device with a plurality of computers.

FIG. 2 is a conceptual diagram for connecting a computer and a printing apparatus by wireless communication. Here, 21 is a personal computer in which a liquid crystal display element is combined as a display, and 23 is a printing device for outputting and recording the calculation results of the computer to the outside. A transmitter 22 is connected to the computer 21 by a predetermined cable, and a receiver 24 is connected to the printing device 23 by a predetermined cable. Here, as the transmission frequency, a UHF band such as a 400 MHz band of a specific low power is mainly used.

With such a configuration, even if the computer is downsized, the transmitter must be connected to the computer, which increases operability and work space. In addition, it requires a separate power supply for the transmitter, which lacks portability.

[0005]

SUMMARY OF THE INVENTION The present invention aims to overcome the above-mentioned drawbacks of the prior art, and provides a novel liquid crystal display device for wireless communication, which has not been heretofore known.

[0006]

The present invention has been made to solve the above-mentioned problems, and a conductive film having a predetermined pattern having a light-transmitting property is provided on a glass substrate, and the glass substrate is paired to form a conductive film. In a liquid crystal display element in which the conductive film surfaces are opposed to each other and an electro-optical medium is sandwiched between the glass substrates, and the conductive film is used as an electrode for driving liquid crystal, the conductive film is used for wireless communication. The present invention provides a liquid crystal display device characterized in that an impedance matching circuit for an antenna is coupled to the conductive film for use as a transmitting antenna or a receiving antenna. Further, the present invention provides the above liquid crystal display element, which is characterized in that an impedance matching circuit for an antenna is formed on a glass substrate.

[0007]

1 is a sectional view of a liquid crystal display device for wireless communication according to an embodiment. 1 and 2 are glass substrates with a thickness of about 1 mm,
Reference numerals 3 and 4 denote translucent conductive films formed on the glass substrates 1 and 2, respectively. The glass substrates 1 and 2 are arranged such that the surfaces on which the respective conductive films are formed face each other, and the electro-optical medium (liquid crystal) 5 is sandwiched between them. 6 is an adhesive for preventing liquid crystal from leaking from the glass substrate. Reference numeral 7 is a liquid crystal backlight composed of a cold cathode discharge tube or a hot cathode discharge tube, and 8 is a polarizing plate.

The conductive films 3 and 4 are arranged so as to form a 480 × 640 matrix pattern as liquid crystal driving electrodes when they face each other, and a predetermined driving voltage is selectively applied to the matrix electrodes. Is applied. The conductive film 3 has 640 vertical stripes and divides the horizontal direction, and the conductive film 4 has horizontal stripes 480 and divides the vertical direction. Therefore, an impedance matching circuit element 9 is coupled to the conductive film 3 in order to act also as an antenna for wireless communication, and the impedance matching circuit element 9 is connected to a computer 10 having a built-in wireless transmitter.

The impedance matching circuit element 9 is specifically an RLC circuit composed of a resistor (R), a coil (L), and a capacitor (C). In this embodiment, the conductive film is 40Ω to 80Ω. In order to do so, a predetermined circuit was constructed. The operating frequency is for the 430 MHz band, and the length of the conductive film 3 as an antenna is about 15 cm. Therefore, in order to reduce the antenna length to 1/4 wavelength, a series resonance circuit in which an inductance is mainly inserted in a matching circuit is used. There is.

As the RLC circuit, it is also possible to form a predetermined ground conductor layer on the opposite surface of the glass substrate on which the conductive film is not formed and form the RLC circuit directly on the glass substrate by a microstrip circuit.

Since the conductive film needs to have translucency, ITO is used.
(Indium tin oxide) film. The electric resistance value of each conductive film is as high as about 1 KΩ to several tens of KΩ, but by connecting each conductive film in parallel, the electric resistance value can be regarded as about several tens of Ω, and it functions as an antenna. It becomes possible. Further, the conductive film may be a material having translucency such as SnO ₂ film other than ITO.

[0012]

According to the present invention, by using a transparent electrode of a glass substrate with a transparent electrode for a liquid crystal display element as an antenna for wireless communication, necessary data can be transmitted / received directly from a computer display.

[Brief description of drawings]

FIG. 1 is a sectional view of a liquid crystal display device for wireless communication according to an embodiment.

FIG. 2 is a conceptual diagram of conventional wireless communication.

[Explanation of symbols]

 1, 2: Glass substrate 3, 4: Conductive film 5: Electro-optical medium (liquid crystal) 9: Impedance matching circuit element 10: Computer 21: Personal computer 22: Transmitter 23: Printing device 24: Receiver

Claims (2)

[Claims] 1. A glass substrate is provided with a conductive film having a predetermined pattern having a light-transmitting property, a pair of the glass substrates are made to face each other on the conductive film surface side, and an electro-optical medium is provided between the glass substrates. In a liquid crystal display element in which the conductive film is sandwiched and used as an electrode for driving liquid crystal, in order to use the conductive film as a transmitting antenna or a receiving antenna for wireless communication, impedance matching for the conductive film is used for the antenna. A liquid crystal display device characterized by combining circuits. 2. The liquid crystal display element according to claim 1, wherein an impedance matching circuit for an antenna is formed on a glass substrate.