JP3175236B2 - Display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called flat panel display, and more particularly to a display device using a small-sized actuator utilizing a film boiling phenomenon of a liquid.

[0002]

2. Description of the Related Art In recent years, flat panel displays using liquid crystal, electroluminescence (EL), plasma (PDP), fluorescent display tubes (VFD) and the like have been widely used in place of CRT displays. The flat panel display is used not only as a display of a laptop personal computer, an operation panel of a telephone, a facsimile, a printer, and the like, but also as a display of a high-definition television, a car navigation system, and the like. In particular, a liquid crystal display using a TFT (thin film transistor) is widely used to make the device thinner and smaller.

[0003] Such a display device is required to have excellent characteristics in all respects such as response speed, simple structure, colorization, viewing angle, display size, etc. from the application. However, no device that satisfies the above characteristics has been proposed in any of the systems. The above-described TFT liquid crystal display also has the drawback that the yield of transistors formed in the display is low and the wiring and structure are complicated.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a display device which can respond at high speed, has a simple structure, and is easy to colorize in view of the above-mentioned conventional problems.

[0005]

According to the present invention, there is provided a transparent substrate,
A first opaque liquid layer, a flexible member at least a part of which is reversibly deformable, a liquid, a heating unit for heating the liquid, a support unit for supporting the heating unit, and the first opaque liquid layer; A second opaque liquid layer communicated by a flow path, and a segment formed by sequentially laminating a pressurizing means, and a film boiling portion is generated in a part of the liquid by a heating action of the heating means to generate a thermal bubble. The flexible member is formed by projecting and displacing a part of the flexible member by the pressure of the thermal bubble to move the liquid of the first opaque liquid layer to the second opaque liquid layer. This is achieved by providing a display device, wherein the display device is brought into contact with the transparent substrate and the display color of the flexible member is visually observed through the transparent substrate.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram illustrating a basic configuration of a display device according to one embodiment. Referring to FIG. 1, a display device 1 includes a substrate 2 serving as a support unit having a large number of resistance heating elements and electrodes to be described later formed on an upper surface thereof, and a sealing material 3
Film 4 as a pressing means adhered through
And a flexible member 6 attached to the upper surface of the substrate 2 via a sealing material 5 and a transparent substrate 7 attached to the flexible member 6 via a sealing material (not shown). ing. Further, between the substrate 2 and the preload film 4, and between the flexible member 6 and the transparent substrate 7, a black sealing solution communicated with a hole described later is stored. A working liquid, which will be described later, is stored between the substrate 2 and the flexible member 6.

The substrate 2 is formed of a silicon wafer, a glass / ceramic substrate, or a heat-resistant film such as polyimide. The preload film 4 is used for applying a constant pressure to the sealing solution sealed between the substrate 2 and the preload film 4. The flexible member 6 is made of a material that can be easily deformed when subjected to pressure from the working liquid due to the generation of a heat bubble, which will be described later, and is made of, for example, white-colored silicon, various photopolymers, and epoxy resins. Have been. The transparent substrate 7 is made of silica glass,
It is made of a hard transparent material such as a quartz plate.

FIG. 1 is a view showing the arrangement of the resistance heating elements and electrodes formed on the substrate 2 among the above-mentioned arrangements. Are arranged on the substrate 2 in the form of a grid in a matrix, and the resistance heating elements 8a, 8b,.
.. are connected between digit lines 9a, 9b... and column lines (column lines) 10a, 10b. Further, the above-mentioned girder lines 9a, 9
.. and the column lines 10a, 10b,... receive a pulse signal from the drive circuit 18 as a control means, so that the corresponding electrodes 11a, 11b,.
, 12a, 12b,... For example, when the resistance heating element 8a is described as an example, both ends of the resistance heating element 8a are connected to the digit line 9a and the column line 10a, and the electrodes 11a,
It drives (heats) according to the pulse signal from the drive circuit 18 supplied to 12a. Similarly, in the case of the resistance heating element 8c, both ends of the resistance heating element 8c are connected to the digit line 9a and the column line 10c.
And is driven according to a pulse signal from the drive circuit 18 supplied to the electrodes 11a and 12c. Also, the other resistance heating elements 8b, 8d,.
It is driven by a so-called time-division pulse signal output from the drive circuit 18.

In the display device 1 configured as described above, a certain area in the display device 1 having one resistance heating element constitutes one pixel, and functions as one small actuator as described later. . The substrate 2 has two holes 13 for each pixel.
a, 13b... are formed, and the above-mentioned sealed solution can move through the holes 13a, 13b.

FIG. 3A is a cross-sectional view for explaining one pixel (small actuator) in the display device 1 having the above configuration. As described above, the resistance heating element 8 is provided on the substrate 2.
a, 8b..., digit lines 9a, 9b.
a, 10b... are provided. The sealing solution is sealed between the flexible member 6 and the transparent substrate 7 as described above.
This encapsulating solution, which is an opaque liquid layer, is hereinafter referred to as a. The sealing solution a is filled with holes (not shown) provided in the flexible member 6 and holes 13a, 13b
.. is in communication with the second opaque liquid layer, the encapsulating solution. The enclosed solution enclosed between the substrate 2 and the preload film 4 is referred to as a '. In addition, this sealing solution a, a '
Are the same solution, a solution in which a black dye is dissolved is used, and pure water or the like is used as a solvent in which the dye is dissolved, for example. On the other hand, the working liquid b enclosed between the substrate 2 and the flexible member 6 contains resistance heating elements 8a, 8b,.
Is a liquid that forms heat bubbles in the liquid when heated and cools the heat bubbles. As the working liquid b, for example, various alcohols such as pure water and ethanol, and various hydrocarbons such as pentane are used.

As can be seen from FIG. 1A, the resistance heating elements 8a, 8b... And the digit lines 9a, 9b. Without being provided, the heat storage layer 14 is provided between them. Also, resistance heating elements 8a, 8b... And digit lines 9a, 9b.
An insulating layer 15 is formed on the column lines 10a, 10b,..., And a protective film 16 is formed on the insulating layer 15. The resistance heating elements 8a, 8b,... Have excellent electric / thermal conversion efficiency such that high heat can be generated immediately by a supplied pulse signal, for example, platinum, titanium,
Materials such as tungsten and tantalum are used. .., Column lines 10a, 10b,.
..., electrodes 11a, 11b ..., 12a, 12b ...
Is made of a common conductive material such as aluminum or copper.

The heat storage layer 14 includes resistance heating elements 8a, 8b,.
Is adjusted so that the Joule heat generated in the step is transmitted to the working liquid b and the substrate 2 in a well-balanced manner, and is made of, for example, a material such as silicon oxide, zirconium oxide, and magnesium oxide. Further, the insulating layer 15 prevents leakage current between the digit line and the column line connected to both ends of the resistance heating element, and prevents an electrochemical reaction due to electric leakage. For example, silicon carbide, silicon oxide, aluminum oxide It is composed of Num and the like. Further, the protective film 16 is provided with resistance heating elements 8a, 8b,.
This is for preventing damage such as .., and is made of a material such as tantalum or polyimide. Further, the heat storage layer 14, the resistance heating elements 8a, 8b,.
9b ..., column lines 10a, 10b ..., insulating layer 15,
The protection film 16 is formed by a known method such as a vacuum deposition method and a vapor phase growth method used when manufacturing a semiconductor device.

In the display device 1 having the above configuration, FIGS. 3A to 3D are state change diagrams for explaining the operation. However, FIG. 3 shows a state change of one pixel, that is, one actuator of the display device 1 of the present embodiment.

First, (1) shown in the figure is an initial state. At this time, any of the electrodes 11a, 1
, 12a, 12b,... Are not output, and none of the resistance heating elements 8a, 8b,. In this state, when the pixels are viewed from above through the transparent substrate 7, the pixels appear black because the sealing solution a is composed of the black dye. At this time, the white color of the flexible member 6 is in a state of being shielded from light by the sealing solution a.

Next, from the driving circuit 18, for example, the electrode 11
a, via 12a (via girder line 9a, column line 10a)
When the pulse signal is supplied to the resistance heating element 8a, a current based on the pulse signal flows through the resistance heating element 8a to generate Joule heat. This Joule heat forms a vapor film 17a on the surface of the protective film 16 located immediately above the resistance heating element 8a. FIG. 2B shows the state at this time. The thickness of the vapor film 17a is several μm when the working liquid b is pure water. Therefore, the resistance heating element 8a (more precisely, the resistance heating element 8a
The protective film 16) directly above a and the working liquid b are insulated by the vapor film 17a, and then the resistance heating element 8a generates heat for a predetermined time (supply time of one pulse signal).
It is hardly transmitted to the working liquid b via 7a but acts mainly on the vapor film 17a to rapidly bring it to a high temperature and high pressure state. Therefore, the vapor film 17a formed on the resistance heating element 8a grows instantaneously and becomes a vapor bubble 17b. Then, the working liquid b receives pressure from the vapor bubble 17b. Therefore, the flexible member 6 that is easily deformed is deformed by being pushed by the internal pressure. A diagram showing this state is (3) in FIG.

The sealed solution a stored between the flexible member 6 having a predetermined volume and the transparent substrate 7 due to the deformation of the flexible member 6 is filled with a hole (not shown) formed in the flexible member 6.
Then, it flows into the storage area between the substrate 2 and the preload film 4 through the hole 13 a formed in the substrate 2. For this reason, as can be seen from (3) of the figure, the flexible member 6 is in contact with the lower surface of the transparent substrate 7 and the white flexible member 6
Is visually observed. Therefore, at this time, the color of the pixel becomes white.

Thereafter, the internal pressure of the vapor bubble 17b which has grown greatly decreases, and the surface area in contact with the low-temperature working liquid b increases, so that a cooling effect is added, so that the vapor bubble 17b starts contracting rapidly and reduces its volume. Then, as shown in FIG. 4D, small bubbles 17c are formed, and the deformation of the flexible member 6 also returns. At this time, since the sealing solution a 'receives a constant pressure from the preload film 4, the sealing solution a' returns to the space between the flexible member 6 and the transparent substrate 7 through the holes 13a and the like, contrary to the above. When the bubble 17c finally ends contracting, the bubble 17c enters the state (1) shown in FIG. For this reason, the color of the pixel viewed through the transparent substrate 7 returns to the black color of the sealing solution a.

The above description has been made on the driving of the pixel where the resistance heating element 8a is located.
.. can be similarly driven. Therefore, by driving each pixel as described above, it is possible to cause each pixel to display the black of the sealing solution a or the white of the flexible member 6, and to create a white or black image on the display screen. . That is, a pulse signal based on the image data from the driving circuit 18 is transmitted to the resistance heating elements 8a and 8b.
, And drive the resistance heating elements 8a, 8b,... To generate a white / black image on the display device 1.

In this embodiment, the creation of a white / black image has been described. However, the above-mentioned black sealing solution a is used, and the flexible member 6 is made of red (R), green (G), or By creating a display device having a structure in which pixels colored in blue (B) are regularly arranged, a pulse signal based on color image data is supplied from the drive circuit 18 to create a color image. The same control can also be performed by regularly arranging pixels in which the sealing solution a is white and the flexible member 6 is colored yellow (Y), magenta (M), or cyan (C). You can also create images.

In this embodiment, each pixel is separated without partitioning. However, in order to efficiently drive (deform) the flexible member 6 in each pixel, each pixel is partitioned by a sealing material or the like. It is good also as composition.

Further, in this embodiment, the heating means is constituted by using the resistance heating elements 8a, 8b,..., But may be constituted by using other heating elements.

[0022]

As described in detail above, according to the present invention, a pulse signal according to image data is supplied to a heating means provided in a display device to instantaneously cause film boiling in a part of the working liquid. The image is displayed using the deformation of the flexible member at this time, so that high-speed and accurate display can be performed.

Further, the display device of the present invention has a simple structure, and wiring and the like are easier than conventional display devices, so that the production yield can be improved. Further, by coloring the flexible member to one of the three primary colors and arranging it regularly, a color image can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a main part of a display device according to an embodiment.

FIG. 2 is a schematic configuration diagram of a display device according to one embodiment.

FIG. 3 is a state change diagram illustrating an operation of the display device according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Display apparatus 2 Substrate 3, 5 Seal material 4 Preload film 6 Flexible member 7 Transparent substrate 8a, 8b ... Resistance heating element 9a, 9b ... Digit line 10a, 10b ... Column line 11a, 11b. ···, 12a, 12b ··· electrode 14 heat storage layer 15 insulating layer 16 protective film 17a vapor film 17b vapor bubble 17c bubble 18 drive circuit

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-58-100823 (JP, A) JP-A-58-220174 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G09F 9/37

Claims (4)

(57) [Claims] 1. A transparent substrate, a first opaque liquid layer, a flexible member at least part of which is reversibly deformable, a liquid, a heating means for heating the liquid, a support means for supporting the heating means, A second opaque liquid layer communicated with the first opaque liquid layer by a flow path, and a segment formed by sequentially laminating a pressurizing means; and a film boiling on a part of the liquid by a heating action of the heating means. A portion is generated to generate a thermal bubble, and the pressure of the thermal bubble causes a part of the flexible member to protrude and displace, thereby moving the liquid of the first opaque liquid layer to the second opaque liquid layer. A display device wherein the flexible member is brought into contact with the transparent substrate, and a display color of the flexible member is visually observed through the transparent substrate. 2. The display device according to claim 1, wherein after the heating operation is stopped, the air bubbles are contracted, and the projecting displacement is restored. 3. The display device according to claim 1, further comprising control means for arranging a plurality of segments and operating heating means for each segment based on display information. 4. The display device according to claim 3, wherein a color display is performed by changing a color of the flexible member and operating the heating means according to display information.