JPH01196019A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To make a high-contrast display at low cost by sandwiching liquid crystal between a transparent substrate where a transparent electrode is formed and a back dielectric substrate, and forming an electrostatic image by a write electrode. CONSTITUTION:The liquid crystal panel is used which has the liquid crystal layer 4 sandwiched between the transparent substrate 1 where the transparent electrode 2 is formed and the dielectric substrate 3 which has no electrode, and ion electrostatic charging is utilized to establish an electric field to be applied to the liquid crystal layer. Namely, ions are generated by the write electrode 5 selectively on the dielectric substrate 3 to form an electrostatic image. The electric field is produced between the ion charged part and transparent electrode and not produced at a part which is not charged with ions, so the orientation of liquid crystal becomes different, so a liquid crystal display corresponding to the electrostatic image is realized. The charged ions work independently, so the electrostatic charging of the ions operates in exactly the same way with an active matrix. Consequently, the size and cost are reducible.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a liquid crystal display device used as an image display device.

(Prior Art) Liquid crystal display devices have been put to practical use, such as a segment type used in watches, calculators, etc., a simple XY matrix type, and an active matrix type using thin film transistors.

(Problems to be Solved by the Invention) The dot matrix type is excellent for realizing large capacity, multi-functional displays, but the simple Therefore, the active matrix type, in which each pixel is provided with a switching element, a diode element, etc., is superior. However, it is difficult to fabricate the switching elements and diode elements over a large area without defects, and this has become an obstacle to increasing the size and reducing costs.

The present invention provides a liquid crystal display device that can be made smaller and lower in cost.

(Means for solving the problems) The present invention will be explained below with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of the present invention. The point is that it uses sandwiched liquid crystal panels. Ion charging is used to create the electric field applied to the liquid crystal layer. That is, ions are selectively charged onto the dielectric substrate 3 by the write electrode 5 to obtain an electrostatic image. The ion-charged portion generates an electric field between it and the transparent electrode 2, and the ion-uncharged portion does not generate an electric field, so that the orientation of the liquid crystal is different and a liquid crystal display corresponding to an electrostatic image can be realized. The charging of these ions acts in exactly the same way as the active matrix because each charged ion acts independently. As the write electrode, for example, a write electrode consisting of a corona ion generator and a control electrode for controlling the flow of the ions as shown in Japanese Unexamined Patent Publication No. 62-34187 can be used.

An example is shown in FIG. A positive or negative voltage of about 3 to 1 OKV is applied to the gold-plated tungsten wire 7 having a diameter of 40 to 120 μm to generate corona ions. The passage of these ions is controlled by the control electrode 8. The control electrode 8 is configured such that an upper electrode 8a and a lower electrode 8b are arranged at a predetermined interval, and a corona ion flow can pass through a through hole provided in the center. Next, the operation will be explained.

When the control power source IO is applied so that the upper electrode 8a is positive and the lower electrode is negative as shown in FIG. 2(a), the electric field becomes forward and corona ions pass through. Conversely, if the control power source 10 is applied with the opposite polarity as shown in FIG. 2(b), corona ions cannot pass through. Note that 11 is a bias power supply. Erasing is performed using corona ions of opposite polarity.

(Effects of the Invention) The present invention can realize a liquid crystal display device having exactly the same functions as an active matrix type liquid crystal display device without requiring a difficult process such as an active matrix forming means. Since there is no limit to increasing the size, it can also be applied to large display devices the size of blackboards.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing one embodiment of the present invention, Figure 2 (a)
, (b) is a circuit diagram illustrating an embodiment of the write electrode and its operating principle. Explanation of symbols ■, transparent substrate 2. Transparent electrode 3, dielectric substrate 4. Liquid crystal layer 5, write electrode
6. Spacer 7, corona wire 8. Ion control electrode

Claims (1)

[Claims] 1. A liquid crystal is sandwiched between a transparent substrate on which transparent electrodes are formed and a back dielectric substrate, and an electrostatic image is formed by controlling the flow of ions on the main surface of the back dielectric substrate on the side not in contact with the liquid crystal layer. A liquid crystal display device characterized in that it is configured to perform display by forming an electrostatic image using write electrodes formed.