JPH0318830A - Display device - Google Patents

Abstract

PURPOSE:To eliminate the restriction of a place to be used, and also, to easily adjust the luminance by providing an illuminating means on the back side of a transparent substrate of the reverse side so that sufficient brightness can be obtained. CONSTITUTION:On the lower side of a transparent substrate 2A, a backlight illumination 20 is provided. The illumination 20 is formed from a U-shaped fluorescent tube 21, and housed in a rectangular parallelopiped-like case 22. Also, the upper opening of the case 22 is formed so as to be closed by an acryl plate 23, and the acryl plate 23 is superposed and placed on the lower side of the transparent substrate 2A. The acryl plate 23 is used in order to diffuse uniformly a light beam from the fluorescent tube 21, and by such a backlight illumination, the uniform illumination can be executed from the back side. In such a manner, a place to be used is not restricted, and also, the luminance can be adjusted freely.

Description

[Detailed Description of the Invention] Field of Industrial Application] The present invention relates to a display device, and in particular, a display device in which a liquid electrochromic substance is sealed between transparent substrates and a voltage is applied to drive electrodes in response to a display signal to perform display. The present invention relates to a display device configured as described above.

[Summary of the invention] A transmissive type display device in which a liquid electrochromic substance is sealed between transparent substrates, and a voltage is applied to a drive electrode in response to a display signal to locally deposit the electrochromic substance to perform display. In the display device, illumination means is provided on the back side, thereby providing a brighter and easier-to-see display.

[Prior Art] For example, as shown in JP-A No. 64-26887, a solution of an electrochromic substance is placed between transparent substrates disposed opposite to each other, and By applying a voltage to the drive electrode, it becomes possible to deposit electrochromic substances in the corresponding areas, and various image displays can be performed by combining such localized deposition of electrochromic substances. It is now possible to use it as a display device. Furthermore, as disclosed in Japanese Patent Application Laid-Open No. 64-26886, a color display can be constructed by arranging color filters of each color of R, G, and B so as to face the drive electrode. Become.

[Problems to be Solved by the Invention K] However, conventional display devices of this type perform display by transmitting natural light from the back side to the front side, and therefore cannot obtain sufficient brightness. Another disadvantage is that the places where it can be used are restricted. Another problem was that the brightness could not be adjusted.

The present invention has been made in view of these problems, and provides a display device that provides sufficient brightness, eliminates restrictions on where it can be used, and allows easy brightness adjustment. The purpose is to provide

Means for Solving Problem 1 The present invention provides a display device in which a liquid electrochromic substance is sealed between transparent substrates and a voltage is applied to a drive electrode in response to a display signal to perform display. Illumination means is provided on the back side of the transparent substrate.

Effect of K] Therefore, the light from the illumination means arranged on the back side of the transparent substrate on the back side is transmitted through this display RM, making it possible to perform a brighter display.

Embodiment K As shown in FIG. 1, the display device 1 has a pair of transparent substrates 2Δ, 2B facing each other. These boards 2A
, 2B are each made of glass. A drive electrode 3 including a polysilicon type thin film transistor (TPT) is formed in a predetermined pattern on the first transparent substrate 2A. On the other hand, on the other transparent substrate m2B facing the drive electrode 3, a counter i-pole 4 made of indium tin oxide (In203.5nu2), for example, is attached over the entire surface, and on this counter electrode 4 is a drive electrode 3. An insulating layer 5 having a pattern corresponding to the electrode 3 and made of silicon oxide (SfOz), for example, is blinded.

A spacer 6 made of a transparent material such as glass is provided between the transparent base 2A and the counter electrode 4 so as to surround the drive electrode 3 and the insulating layer 5. Thus, the transparent substrate 2A,
A sealed space 7 surrounded by a spacer 6 and a counter electrode 4 is formed, and an inorganic material such as silver iodide (
Electrochromic solution (EC solution?
1i) 8 is sealed, and thus the display portion 9 is formed by the sealed space 70 portion.

In the display section 9, the insulating layer 5 is arranged in the X direction and in the Y direction, as shown in FIG.
The adjacent insulating layers 5 are separated from each other by a linear partition space 11X in the X direction, and by a linear partition space 11X in the Y direction. The electrochromic material is separated from each other by the space 11Y, forming transmission windows corresponding to the pixels arranged in a matrix, and exposing the counter electrode 4 at the bottom of the partition space so as to surround the transmission window of each pixel. territory 1
g! 12X and 12Y are formed.

Furthermore, an electrochromic substance deposition region 12S is provided in which the counter electrode 4 is exposed, in a portion surrounding the region where the insulating layer 5 is arranged in a matrix.

This electrochromic substance precipitation region 125 is provided over a sufficiently wide area for practical purposes between the periphery of the region where the insulating layer 5 is attached and the spacer 6. Further, each of the drive electrodes 3 is driven by a matrix drive circuit.

In the above configuration, the counter electrode 4 is grounded, and when a predetermined positive drive voltage is applied to the drive electrode 3 facing each insulating layer 5 via the EC solution 8,
An inorganic EC substance, such as silver iodide, dissolved in the EC solution 8 undergoes an electrochemical reaction using the drive electrode 3 as an anode and the counter electrode 4 as a cathode, thereby forming an exposed portion of the counter electrode 4, that is, an electrochromic substance deposition region. 12X
, 12Y, and 128 as a black color.

On the other hand, when a predetermined negative drive voltage is applied to the drive electrode 3, the counter electrode 4 is used as the anode, and the drive electrode 3 is used as the anode, and an electrochemical reaction occurs in the same manner as described above, so that EC is generated on the drive electrode 3. The substance is colored black and precipitates.

Here, the electrochromic substance precipitation area of the counter electrode 4 [
12X, 12Y, and 128, a sufficient amount of EC material is deposited at all times, while an amount of EC material corresponding to the luminance of each pixel of the black and white display signal is deposited on the drive electrode 3. A drive current of a certain amount is caused to flow into the drive signal line from the drive signal line.

Only the insulating layer 5 remains transparent on the opposite electrode 414, and is separated from the insulating layer 5 in the X direction and in the Y direction.
A pattern is formed in which the electrochromic substance deposition regions 12X, 12Y and the electrochromic substance deposition region 12 formed in the directional partition spaces 11X and IIY are black.

On the other hand, the drive electrode 3 has a pattern that faces the insulating layer 5, and the ECI quality that faces the luminance of each pixel of the black and white display signal is deposited on the drive electrode 3 of the transparent substrate 2A. In response to the black and white display signal, an image having a light transmission amount distribution corresponding to black, intermediate color or white is generated for each pixel.

Thus, for example, when irradiation light enters from the lower side of the transparent electrode Vj12A, a light flux having a brightness distribution corresponding to the light transmission amount distribution of each drive electrode 3 passes through the EC solution 8, and further passes through the opposing insulating layer 5. The light passes through the transparent substrate 2B and is emitted to the outside as output light LA. As a result, the observation name 14 viewing the output light LA becomes able to observe a black and white image corresponding to the black and white display signal supplied to the drive electrode 3 of the transparent substrate 2A.

In the display device @1 that performs display in this way, the first
A backlight 20 is provided below the transparent substrate 2A arranged on the lower side in the figure. This lighting 2
0 is formed from a U-shaped fluorescent tube 21, and is housed in a rectangular parallelepiped case 22 as shown in FIG. The upper opening of the case 22 is the acrylic plate 2.
3, and this acrylic plate 23 is placed under the transparent substrate 2A. The acrylic plate 23 is used to diffuse and make the light from the fluorescent tube 21 uniform, and by using such a backlight, uniform illumination is provided from the rear side.

In this way, this embodiment uses a fluorescent tube 21 with a color temperature of 7000° or more, and a diffuser plate made of an acrylic plate 23 to keep the uniformity constant is arranged. Miniaturization is achieved by the shaped fluorescent tube 21. Incidentally, in the case of increasing the size, a linear fluorescent tube may be used. In the case of heating bulb lamps or ordinary fluorescent lights with a color temperature of 4000° or less, the color temperature is 5000"
Fluorescent tube 21 with a color temperature of 7000'K or higher, although it has the disadvantage of a reddish tinge in color reproducibility at ~6500'K.
By using this, it is possible to obtain a uniform, clean white display with high color rendering properties.

In other words, such backlight illumination 20 makes it possible to provide an electrochromic display device with white color and sufficient brightness.

APPLICATION EXAMPLE E Although the present invention has been described above with reference to an illustrated embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made based on the technical idea of the present invention. For example, although the above embodiment relates to a black and white display device, it is also applicable to a color display in which R, G, and B color filters are arranged on the counter electrode. Furthermore, the liquid electrochromic substance is not limited to the silver iodide (Ag I) solution used in the above embodiments, but an 11Ec solution may also be used.

K Effects of the Invention As described above, the present invention is a transmission type display device using a liquid electrochromic substance, in which illumination means is provided on the back side of the back side transparent substrate. Therefore, a display device that has sufficient brightness, is not restricted in the place where it can be used, and can freely adjust its brightness will be provided.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part of a display device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line ■ to ■ in FIG. 1, and FIG. 3 is an enlarged front view of a main part showing a pattern of an insulating layer. , FIG. 4 is an exploded perspective view showing the backlight illumination. In addition, the names of the main parts in the drawings are as shown. 1...Display device i 2△, 2B...Transparent substrate 3...Drive M pole 4...Counter electrode 7...Sealed space 8... ...Electrochromic solution 20...
... Backlight illumination 21 ... U-shaped fluorescent tube 23 ... Acrylic plate

Claims (1)

[Claims] 1. In a display device in which a liquid electrochromic substance is sealed between transparent substrates and display is performed by applying a voltage to a drive electrode in response to a display signal, the back surface of the transparent substrate on the back side A display device characterized in that a lighting means is provided on the side.