JPS5972477A - Display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel image display method, display element, and display device.

Currently, cathode ray tubes (so-called CRTs) are widely used as terminal displays in various office equipment and i17+1 equipment, or as displays in monitors for televisions and video cameras. However, dissatisfaction remains with this CRT in that its image quality, resolution, and display capacity do not reach the level of hard copies made using silver halide or electrophotography. In addition, as an alternative to CRT, attempts have been made to commercialize so-called liquid crystal panels that display dot matrix images using liquid crystals, but these liquid crystal panels also lack driveability, reliability, productivity, and durability. In this respect, nothing satisfactory has yet been achieved.

Therefore, an object of the present invention is to solve the problems that could not be solved by the conventional techniques in this technical field.

In other words, the objects of the present invention are a method of displaying high-resolution and high-quality images, a novel display element that has excellent drive performance, productivity, durability, and reliability and has high density pixels, and a display device using the same. The purpose is to provide

Embodiments of the display of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic cross-sectional view for showing the image forming principle of the display element according to the present invention. FIG. 1(A) shows a transmissive display element DE, and FIG. 1(B) shows a reflective type The display elements DE are shown respectively. A heating element 1 is used to change the physical properties of the liquid layer 2, which is made of a liquid that is transparent to visible light, and to heat the liquid layer 2 to an extent that boiling does not occur in the liquid layer 2. As will be described later, this heating element 1 generates heat in various forms such as a dot matrix shape (a dotted line shape), a dot line shape (a dotted line shape), a line shape, an island shape, etc., and heats the liquid layer 2 by heat conduction. .

Examples of the heat generating element l include those that utilize radiation heating, which will be described later, and those that utilize Joule heat such as resistance heating. When the display element []E is of a transmissive type, the heating element l is required to be transparent to visible light. Reference numeral 2 denotes a liquid layer made of a liquid that is transparent to visible light, and the basic composition of this transparent liquid is water or various organic solvents used alone or in combination. Examples of various organic solvents used for this include methyl alcohol, ethyl alcohol, n-propyl alcohol, inpropyl alcohol, n-butyl alcohol, 5eC-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, pentyl alcohol, hexyl alcohol, and heptyl alcohol. Alkyl alcohols such as alcohol, octyl alcohol, nonyl alcohol, and decyl alcohol; For example, carbide-based solvents such as hexane, octane, cyclopentane, benzene, toluene, and quidylol:
For example, halogenated hydrocarbon solvents such as carbon tetrachloride, trichloroethylene, tetrachloroethylene, tetrachloroethane, and dichlorobenzene; For example, ether solvents such as ethyl ether, butyl ether, ethylene glycol diethyl ether, and ethylene glycol monoethyl ether; Ketone solvents such as acetone, methyl ethyl ketone, methyl propyl ketone, methyl amyl ketone, cyclohexanone; ester solvents such as ethyl formate, methyl acetate, propyl acetate, phenyl acetate, ethylene glycol monoethyl ether acetate-1; for example, diacetone Alcohol solvents such as alcohol; Amides such as dimethylformamide and dimethylacetamide; Triethanolamine,
Amines such as jetanolamine; For example, polyalkylene glycols such as polyethylene glycol and polypropylene glycol; Ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, and alkylene glycols; For example, polyhydric alcohols such as glycerin; Petroleum Examples include hydrocarbon solvents. The thickness of the liquid layer 2 is preferably within the range of 1 scale to 1 square inch.

3 is a transparent protective plate, which is made of translucent (colorless to light-colored) glass or plastic that has as much pressure control as possible. Note that this protective plate may not be used when the display element DE is arranged horizontally. 5 is a substrate, and in the case of the transmissive display element DE shown in FIG. In the case of the reflective display element DE shown in FIG. 1(B), a member having pressure resistance is used. Although the heat generating element 1 is provided on the substrate 5, the heat generating element 1 and the substrate 5 may be used in common, and the heat generating element may not require the substrate 5 in some cases. Basically, the substrate 5, heat generating element 1, liquid layer 2, and transparent protection plate 3 are laminated in this order to constitute the display element DE according to the present invention. Reference numeral 4 denotes illumination light that is incident on the display element DE in the form of parallel light, which is natural light or light from a light source not shown, and is incident on both the non-heating section and the heating section 1a of the heat generating element 1. 13 is a liquid layer heating part, which is a high temperature area formed by heating a part of the low temperature area of the liquid layer 2 with a heating element 1 to an extent that it does not boil;
For example, it shows the part of the liquid layer 2 heated by the heating part 1a where the heating element 1 generates heat, and there may actually be a temperature gradient from the heating part 1a to the surrounding liquid layer. , the physical properties of the liquid in the liquid layer 2 in this part have changed from the physical properties before heating by the heat generating element 1 (however, when the liquid layer 2 is preheated by the heat generating element 1, the properties of the liquid layer being preheated are Since the liquid layer 2 is further heated to form the liquid layer heating section 13 from the state, the physical properties of the further formed liquid layer heating section 13 are changed from the physical properties of the liquid layer 2 in the preheated state. ).

This change in physical properties of the liquid layer 2 particularly means a change in optical properties; for example, specifically, changes in the refractive index, density, polarizability, etc. of the transparent liquid that constitutes the liquid layer 2. It means. For example, regarding the refractive index, assume that the temperature of the translucent liquid in the liquid layer 2 rises from the temperature L'C to the temperature (t+Δt)'c due to heat generated by the heating portion 1a of the heat generating element 1.

In this case, the refractive index of the transparent liquid at temperature t'c is N
The refractive index at temperature (t+△t)”c is N+Δ
When N is equal to N, the refractive index gradient is ΔN/Δty-to (1/℃)
It is. Although the rate of change in the refractive index, that is, the change in the refractive index with respect to temperature is small, when a minute region of the liquid layer 2 near the heating section 1a is heated, the refractive index gradient in the minute region is large, and therefore, this heating The liquid layer heating section 13 in the minute region thus formed has power, and (11) light is refracted, scattered, diffracted, etc. in the region where the refractive index gradient is large. Note that the value of ΔN/Δ is not limited to negative values.

The heating portion 1a of the heating element 1 generates heat to an extent that the translucent liquid of the liquid layer 2 is heated to such an extent that boiling does not occur and its physical properties change as described above, thereby forming the liquid layer heating portion 13. Since the other parts of the heating element 1 do not generate heat, the physical properties of the liquid layer 2 in the corresponding low temperature region hardly change, and the physical properties are approximately the same. Even in the low-temperature region, it is actually heated by heat conduction from the heating section, etc., and the optical properties change, but this can be relatively ignored in terms of changes in the heating section. Liquid layer heating section 13 of liquid layer 2 of display element f-DE. Illumination light 4 incident on the other side travels straight within the liquid layer 2 and is indexed as parallel light from the display element DE. Of course, in the case of a transmissive display element J'DE, the path of the illumination light 4 at this time is such that it enters from the back of the display element/-DE and then passes through the display element DE.
Inject in front of.

That is, the illumination light 4 is emitted through the substrate 5 → the heating element 1 → the liquid layer 2 (low temperature region) → the transparent protection plate 3. Further, in the case of a reflective display element DE, the illumination light 4 enters from the front surface of the display element DE and exits from the front surface. That is, the illumination light 4 is reflected from the transparent protection plate 3 → liquid layer 2 (low temperature region) → the surface of the heat generating element 1 (if the heat generating element 1 is non-reflective, it is reflected by a light-reflective reflective film (not shown)) → the liquid Layer 2 (low temperature area) → Transparent protection plate 3
The light is then emitted from the display element DE. On the other hand, the path of the illumination light 4 passing through the liquid layer heating section 13 which is a high temperature region of the liquid layer 2 passes through the liquid layer heating section 13 described above except for passing through the liquid layer heating section 13 within the liquid layer 2. The path of the illumination light 4 in the display element DE is exactly the same as that of the illumination light 4 that is not used. However, the illumination light 4 passing through the liquid layer heating section 13 is refracted, scattered, diffracted, etc. due to the refractive index gradient (gradient end index) thermally generated in this section, and is refracted instead of going straight through the liquid layer 2. The optical path changes. Therefore, the illumination light 4 passing through the liquid layer heating section 13
When the illumination light 4 and the illumination light 4 that do not pass therethrough are emitted from the display element DE, they do not become parallel light, and their emission directions are different from each other. When the heating part 1a of the heat generating element l stops heating, the liquid layer heating part 13 is no longer cooled, and the direction of the illumination light 4 emitted from the display element DE is all directed to the liquid layer heating part 1.
It will be in the same direction as Atsushi who passed through the part other than 3. Therefore, the illumination light 4 that passes through the high temperature region of the liquid layer heating section 13 and the illumination light 4 that passes through the low temperature region of the liquid layer 2 that is not the liquid layer heating section 13 are optically distinguished. The display element DE according to the present invention is capable of direct viewing under certain illumination conditions (for example, illumination with parallel light), but can be further used as a display device by combining with an imaging optical system described below. And its utility value will expand. In the case of the former direct view display,
Display pixels can be identified based on the difference in the amount of light that reaches an observing eye (not shown) positioned with respect to the direction of the light that has passed through the liquid layer heating section 13. In the case of the latter combination of display element DE and an imaging optical system described below, the imaging position of the liquid layer heating section 13 of the liquid layer 2 by the imaging optical system and the heating element other than the liquid layer heating section 13 of the liquid layer 2 1 (including the case where the liquid layer 2 is preheated by the heat generating element 1) (hereinafter referred to as the liquid layer non-heated part) is imaged by the imaging optical system. Since the display points are different, the display points can be more clearly identified by defocusing. Therefore, by defocusing, a bright spot can be inverted and displayed as a dark spot. When the imaging optical system described below is not used, parallel light is used as the illumination light 4 to increase the display effect of one display element DE, and the display effect can be dramatically improved by adding a light-shielding grating as described below. d. In Fig. 1, the heat generating element 1 is in direct contact with the liquid layer 2 to heat the liquid layer 2, but the heat generating element 1 is arranged near the liquid layer 2 to heat the liquid layer 2 by thermal conduction heating. You may. For example, in FIG. 1B, if the heat generating element 1 does not reflect light, a light reflective metal film, dielectric mirror, etc. is interposed between the liquid layer 2 and the heat generating element 1.

In addition, in this example, in order to make the explanation easier to understand, the light beam incident on the display element DE is assumed to be parallel light, but the light beam incident on the display element DE is not limited to parallel light. The liquid layer heating section 13 in the high temperature region of the liquid layer 2 is formed in the optical path due to the heat generated by the heating section 1a of the liquid layer 1, thereby changing the optical path compared to the optical path before the liquid layer heating section 13 was not formed. It uses

FIG. 2 is a schematic cross-sectional view of the display element for more specifically explaining the image forming principle of the display element according to the present invention.
IΔ(A) shows a transmissive display element DE, and FIG. 2(B) shows a reflective display element DE.

In the figure, 6 is a radiation absorption layer that absorbs radiation 6a and generates heat, 2 is a liquid layer, and 3 is a transparent protective plate. Basically, the display element DE is constructed by laminating these layers. has been done. In the reflective display element DE shown in FIG. 2(B), 9 is a pressure absorbing film that absorbs the increase in pressure when the liquid layer 2 is heated, and 8 is a pressure absorbing film used for display. illumination light 4
20 is a heating layer for preheating the liquid layer 2. These reflective film 8, pressure absorbing film 9, and heat generating layer 10 are not necessarily required for the display element DE, and are used as necessary. for example,
When the liquid layer 2 is heated, the internal pressure of the liquid layer 2 does not increase significantly [14? In this case, the pressure absorption film 9 is not used, and the reflection layer 8 is not used when the radiation absorption layer 6 has light reflectivity, and the radiation absorption layer 6 of the radiation 6a is not used when the liquid in the liquid layer 2 has low sensitivity. In the case where the liquid layer 2 is heated with sufficient responsiveness by heat generation of the radiation absorbing layer 6 only by irradiation to form the liquid layer heating section 13, the heating element layer 10 is not used. However, since the heat generating layer 10 will be described later, the description will be made assuming that the heat generating layer 10 is not present in FIG. 2(B). In addition, these pressure absorption 11Q
9 and the heat generating layer 10 are also used in the transmission type display element DE shown in FIG. 2(A), if necessary. The radiation absorbing layer 6 efficiently absorbs radiation 6a, particularly infrared rays, and generates heat, but it is difficult to melt itself due to the heat generated. This radiation absorbing layer 6 is obtained by forming a film (including a multilayer film) of various inorganic or organic materials. Since the radiation absorbing layer 6 itself has a film thickness of only a few liters, it generally lacks a supporting function, so it is generally recommended to add a radiation-transparent support plate made of glass, plastic, etc. (not shown) as a substrate. It is true. The translucent liquid constituting the liquid layer 2 is of the types mentioned above, and generally means a liquid that is translucent to visible light, and a translucent liquid is a liquid that is translucent to visible light. It does not matter whether it is transparent to 6a or not. Reference numeral 7 denotes a grating which, when the liquid layer 2 is not heated, enters the display element DE and transmits through the transmissive display element IDE, or the reflective display element DE.
t, thereby blocking the illumination light 4 reflected and emitted from the display element DE. Display element DE configured in this way
On the other hand, when radiation (particularly infrared rays) 6a is irradiated from the right side of the drawing, corresponding points on the radiation absorbing layer 6 generate heat. When a part of the radiation absorption layer 6 generates heat in this way, the liquid in the liquid layer 2 that is in contact with or in the vicinity of this layer is heated by thermal conduction, and the temperature of the liquid changes to ``-H'', which changes its physical properties. This changes from before, and a liquid layer heating section 13 in the high temperature region of the liquid layer 2 is formed. The illumination light 4 passing through this liquid layer heating section 13 is
When passing through the liquid layer heating section 13, the optical path is changed by the mechanism described above in FIG. At least a portion of the illumination light 4 that has undergone this optical path change passes through the opening of the grating 7 when exiting the display element DE. On the other hand, all of the illumination light 4 that does not pass through the liquid layer heating section 13 is blocked by the grating 7, so when viewing the display element DE through the grating 7, the liquid layer 2 on which the liquid layer heating section 13 is formed can be seen. The illumination light 4 that passes through the portion of the liquid layer 2 and the illumination light 4 that passes through the non-heated portion of the liquid layer 2 are distinguished.

Of course, if the illumination light 4 passing through the non-heated part of the liquid layer is made to pass through the opening 1 of the grating 7, when the liquid layer heating part 13 is formed, the illumination light 4 passing through this part will pass through the opening 1 of the grating 7. 7, there is also an opening in the grating 7 through which the illumination light 4 does not pass, and a display element having the reverse form of the above-mentioned embodiment is also possible.

Even if the grid 7 is not provided, the direction of the illumination light 4 passing through the liquid layer heating section 13 and the direction of the illumination light 4 passing through the liquid layer non-heating section of the liquid layer 2 are mutually exclusive when exiting the display element DE. Since they are different, the illumination light 4 can be optically identified when looking toward the direction in which either one of the light beams comes.

Note that when irradiating the display element DE with the radiation 6a,
It is possible to irradiate in a pattern corresponding to a predetermined image, or it is possible to use a laser light source to irradiate a large number of beams at once in a dot shape using the radiation 6a as a beam. Alternatively, a method may be adopted in which the radiation absorption layer 6L is scanned with one line beam.

Further, the direction in which the radiation 6a is irradiated is not limited to the illustrated example in the case of the transmissive display element -J'-DE shown in FIG. 2(A). That is, when the radiation 6a passes through the liquid layer 2 on the transparent protection plate 3, it is also possible to irradiate the radiation 6a from the left side of the drawing. Note that the display is naturally erased by cooling the liquid layer heating section 13. This point differs from the thermo-optic effect of conventionally known liquid crystals. In other words, the thermo-optical effect of liquid crystal changes from a transparent state to an opaque state or vice versa due to thermal changes, but once the changed state is memorized, it cannot be returned to the original state simply by returning the temperature to the original state. No (because the molecular arrangement is confined). however,
Liquid crystals are also within the technical scope of the present invention as long as they are used within the scope of the principle of the present invention, that is, the optical properties are thermally reversible.

This is because the use of such liquid crystals has not been previously known.

Although the method for forming display pixels by radiation heating has been described above, in the present invention, the radiation absorbing layer 6 in FIG. It is also possible to modify the heating element f (not shown) so as to bring it into close proximity or contact with the heating element f to heat the liquid by conduction.

In the present invention, in order to further enhance the discrimination effect of display pixels, the above-mentioned anti-In II! 8 may be separately provided.

Such a reflector III 8 must be formed of a high melting point metal or metal compound material that does not melt itself during heat conduction.

In order to obtain an effective display in the present invention, the radiation absorbing layer 6
Although it is necessary to heat the liquid surface of the liquid layer 2 in contact with the liquid layer 2 and the liquid layer 2 in the vicinity thereof, it is not a requirement that the heating extends to the liquid surface of the liquid layer 2 in contact with the transparent protection plate 3 and the vicinity thereof. .

However, the liquid layer 2 in contact with the heating surface of the radiation absorbing layer 6
The liquid level and the temperature of the liquid layer 2 in the vicinity are
Experiments have shown that the higher the temperature is, the higher the display contrast of the display element DE is. Furthermore, if this is actively utilized, it becomes possible to display intermediate tones by varying the amount of heat for heating the liquid R2.

Incidentally, the smaller the irradiation spot diameter for irradiating the radiation 6a onto the radiation absorption R6, the better the contrast of the display, and the preferred spot diameter (diameter) of the radiation 6a is 0.5. -100 ru is appropriate.

However, a display image can be obtained even if the radiation absorption layer 6 is irradiated with the radiation 6a of a rectangular light beam having a width of 2II11 and a length of 10mm. The term "liquid layer heating section 13" often used in the detailed description of the present invention includes the latter range. However, even if the liquid layer heating part 13 of the liquid layer 2 is not very small, the temperature of the heating surface is not uniform, so the direction of the optical path of the light in the liquid layer heating part 13 and the direction of the light in the non-heated part of the liquid layer are different. A discrimination effect will occur if there is a difference in the direction of the light path. Therefore, in the present invention, the liquid layer heating section 13 is not limited to a minute range.

In the present invention, the boiling point of the liquid constituting the liquid layer 2 is -1
Since it is not heated to -, no steam bubbles are generated and no sudden pressure increase occurs.

Therefore, damage to the display element DE due to the above-mentioned pressure does not pose much of a problem. However, it is assumed that the pressure of the display element DE will be increased by heating the first liquid layer 2, albeit slightly, and that bubbles may be generated in the event of some kind of force majeure accident. There may be a need to keep it.

Therefore, in preparation for such a case, it is desirable to connect this liquid layer 2 to an air chamber or an accumulator (not shown) to alleviate the increase in pressure in the liquid layer 2. or,
As another method, as shown in FIG. 2(B), the display element D
A pressure absorbing membrane 9 is placed in E between the liquid layer 2 and the transparent protection plate 3.
By intervening, the pressure generated in the liquid layer 2 may be absorbed.

Of course, if you use the two methods described above, it will be even more effective.
Effective. The pressure absorbing membrane 9 is made of a translucent elastic material or a highly viscoelastic material, and may also be made of a so-called sponge that contains air bubbles or has ventilation holes.

Furthermore, if air bubbles made of room temperature gas are generated or mixed into the liquid layer 2, a means for removing such air bubbles is required. I could even linger.

As another means, air bubbles can be removed by pressure or suction using a pump or syringe (not shown).

In this embodiment, as shown in FIG. 2(B), in order to greatly speed up the formation speed of the liquid layer heating section 13 as a display pixel, when the reflective film 8 is not used, the display element DE A heating element layer 10 that generates heat by Joule heat is provided between the radiation absorption layer 6 and the liquid layer 2, or between the radiation absorption layer 6 and the reflection film 8 when the reflection film 8 is used. It is desirable to preheat the liquid layer 2 6. At this time, if the radiation absorbing layer 6 or the reflective film 8 is a conductor, an insulating layer (not shown) is placed between them and the heating layer 10. It is desirable to provide

As such a heating element layer 10, a dowel, a linear heating element corresponding to one or more scanning lines of a radiation beam, a grid heating element (none of which are shown), etc. are suitable. When the heating element layer io is a linear heating element, it is thought that good display results can be obtained because the heating portion is minute in the width direction. At this time, it is preferable to synchronize the irradiation of the radiation 6a to the radiation absorbing layer 6 and the heating of the liquid layer 2 by the heating element layer 10. Examples of materials for such a heating element layer 10 include metal compounds such as hafnium boride and tantalum nitride, and alloys such as chromium.

Furthermore, in the present invention, a structure of the display element DE in which a corrosive component comes into direct contact with the liquid layer 2 should be avoided, since this will shorten the life of the element DE. In other words, in a configuration where a corrosive component is in contact with the liquid layer 2,
There are many cases where the display element DE is damaged or deteriorated due to chemical corrosion, thermal oxidation, etc.

Therefore, in such a case, it is desirable to form a corrosion-resistant protective film (not shown) at the interface between the liquid layer 2 and the corrosive component, and the material for this protective film is silicon oxide. , dielectric materials such as titanium oxide, heat-resistant brass tink, and the like.

In the present invention, of course, the reflective film 8 may also serve as this protective film depending on its function.

Note that when a metal or the like is used as the radiation absorbing layer 6, it is generally formed into a film on a radiation transparent support plate as a substrate, so when the radiation absorbing layer 6 is heated, , there is no need to worry about it being oxidized by external air. If the radiation absorption rate of the radiation absorption layer 6 is not perfect, an anti-reflection I pattern (not shown) is provided on the side to which the radiation 6a is irradiated.
By applying this, the absorption rate of the radiation 6a of the radiation absorption layer 6 can be significantly increased.

Next, as an application example, a light valve type projection device will be explained with reference to FIGS. 3 to 9. A light valve is a device that controls or adjusts light, and therefore, light from an independent light source is controlled by a suitable medium (in this example, the liquid layer of the display element) to illuminate the screen. - All displays that project images on the screen are included in this category. Compared to self-luminous displays such as cathode ray tubes, this method can theoretically increase the size and brightness of the display screen by increasing the intensity of the light source used, so it is especially suitable for large screen displays that require a large amount of light. suitable for Among them, the one shown in Figure 3 is also called Schlieren Light/Help, which creates patterns with different refraction angles, diffraction angles, or reflection angles of light in a liquid layer, which is a control medium, according to input signals. This method uses a schlieren optical system to convert the changes into bright and dark images, which are then projected onto a screen.

FIG. 3 is a schematic configuration diagram for explaining the basic principle of the display device. The image of each slit of the first grating 7a is arranged to form an arrow/z image on each par of the second grating 7b so as to be shielded by the Schlieren 1/lens 11. The liquid layer as a medium of the transmission type display element DE placed between the Schlieren lens 11 and the second grating 7b is not heated, and its physical properties (for example, refractive index) are extremely smooth. If there is, all the incident light that has passed through the first grating 7a is blocked by the second grating 7b and does not reach the screen 12i. However, when a part of the liquid layer of the display element DE is heated by the heating element and reaches a high temperature, forming the liquid layer heating part 13, the optical path force 1 of the light passing there changes as described above. The incident light 14 that has passed through the second grating 7b reaches the screen 12 through the gap (open) in the second grating 7b without being blocked by the second grating 7b. Therefore, 1 display element i DE
The imaging lens 1 is arranged to form an image on the screen 12 of the heating surface heating the liquid layer heating section 13 or the medium surface near the heating surface.
1', a bright and dark image corresponding to the temperature change ψ of the liquid layer of the display element DE can be obtained on the screen l2-1=j. Note that the openings of the first and second gratings 7a and 7b used for this may be linear or dot-shaped.

4 and 5 are schematic configuration diagrams of modified embodiments of the display device of FIG. 3. FIG. In FIG. 4, reference numeral 14' denotes a light source, which is placed at the focal point of the lens lla, so that all the light beams from this point on pass through the lens 11a and become parallel light beams.

This parallel light beam enters as incident light 14 from the back surface of the transmissive display element DE. 7C is a light-shielding filter, which is placed at the condensing point of the condensing lens llb, so if the display element f
-D If the physical properties (e.g. refractive index) of the liquid layer of E are uniform, then
The light 14 of the person 114 passes through the display element DE as it is and is focused on the light shielding filter 7C via the condenser lens Ilb.

As a result, the incident light 14 does not reach the screen 12 placed behind the light blocking filter 7C at all. However, when a part of the liquid layer of the display element DE is heated to a high temperature and a liquid layer heating part 13 is formed, the optical path of the light passing through that part of the display element DE changes as described above. The incident light 14 that has passed through reaches the screen 12 without being blocked by the light blocking filter 7C.

Therefore: If the condenser lens Ilb is arranged so that the heating surface heating the liquid layer heating section 13 of the display element DE or the medium surface in the vicinity thereof is imaged on the screen 12J, the liquid layer of the display element DE A brightness/darkness image corresponding to the amount of temperature change is obtained on the screen 12.

FIG. 5 is a schematic diagram of a modification of the display device of FIG. 4 for obtaining an inverted image. 14' is a light source placed at the focal point of lens 1.1a, llb is a condensing lens, and light source 1 is made into a parallel beam by lens lla.
This is for condensing the incident light 14 from 4' onto the focal position. A light shielding filter 7d is arranged at the focal point of the condenser lens llb, which passes only the light beam passing through the focal point, that is, the focal point. Further, a transmissive display element DE is arranged between the condenser lens llb and the light-blocking filter 7d, and a screen is arranged behind the light-blocking filter 7d. When the liquid layer heating section 13 is not formed in the transmissive display element DE, all the incident light 14 is condensed by the condenser lens flb.
The light passes through this focal point and reaches the screen 12.

However, when the liquid layer heating section 13 is formed in the display element D'E, the light passing through this section changes its optical path and becomes scattered light, and is blocked by the light blocking filter 7d, so the screen 12L
There are points where the light does not reach, and a bright and dark image is formed.

FIG. 6 is a schematic diagram of another modification of the embodiment of the display device shown in FIGS. 4 and 5. FIG. The light beam from the light source 14' is made into parallel light by the lens lla, and the light beam is turned into parallel light by the half mirror 1.
The incident light 14 enters the reflective display element DE through the light ray 5'. If the physical properties (e.g. refractive index) of the liquid layer of the display element r-DE are uniform, then the incident light 1 to the display element DE
4 is reflected by the display element DE, and this reflected light, like the incident light 14, is parallel light and is condensed at a condensing point via a condensing lens llb. If a light-blocking filter 7c (in this case, the light-blocking filter 7d is not arranged) is placed at this light-converging point i, the light focused on this light-converging point will be blocked by the light-blocking filter 7c and reach the screen 12. do not.

However, when a part of the liquid layer of the display element DE is heated to form a liquid layer heating part 13 in a high temperature region, the light incident on this part changes its optical path and is reflected, passing through the condensing lens llb. and reaches screen 12-J-. If this condensing lens llb is arranged at a position where it images the heating surface heating the liquid layer heating section 13 or the medium surface in the vicinity thereof on the screen 12, the temperature of the liquid layer of the display element DE A contrast image corresponding to the amount of change is obtained on the screen 12-.

In addition, in order to obtain an inverted image on this screen, a light shielding filter 7d, also indicated by a dashed line, is used instead of the light shielding filter 7c, which passes only the light that passes through the condensing point indicated by a dashed dotted line. Just place it as you like. In this case, most of the scattered light from the liquid layer heating section 13 of the display element DE is blocked by the light blocking filter 7d, and the non-scattered light passes through the light blocking filter 7d and reaches the screen 12, so that the above-mentioned inverted image is obtained.

FIG. 7 is a schematic diagram of a transmission type light valve type projection device, and shows an example of the arrangement of signal input means for a transmission type display element DE. 7a is a first grating, DE is a transmission type display element, 11 is a schlieren lens, 7b is a second grating, 11' is an imaging lens, and 12 is a screen, and these structures are similar to the configuration of the display device in FIG. Similar.

A signal light of radiation (mainly infrared rays) 6a modulated through a laser light source and a light modulator (not shown) is sent to a horizontal scanner 1.
Horizontally scanned by a rotating polygon mirror 7,
ie, a rotating polygon mirror as a vertical scanner 16,
Alternatively, it is vertically scanned by a galvanometer mirror, reflected by a cold filter 15, and focused on the radiation absorption layer 6 of the transmission type display element DE shown in FIG. 2(A), forming the liquid layer 2 in a dot matrix shape. A two-dimensional image of the liquid layer heating section 13 is formed by heating. On the other hand, since the incident light 14 that has passed through the first grating 7a passes through the cold filter 15, the third
A two-dimensional visible image corresponding to the liquid layer heating section 13 of the display element DH is formed on the screen 12 by the mechanism described above in the figure. It goes without saying that the radiation absorbing layer 6 of the display element DE used in this figure must be transparent to visible light.

Note that semiconductor laser arrays or light emitting diode arrays (
If a horizontal scanner 17 is used, the horizontal scanner 17 can be omitted. Further, the cold filter 15 and the galvanometer mirror may be used in common.

Note that the transmission type display element rDE shown in FIG.
When applied to FIGS. 5 to 5, for example, the laser oscillator, horizontal scanner 17, lens lie, vertical scanner 16, cold filter 15, etc. described in FIG. 7 may be used for the incident method of the radiation 6a. At this time, the cold filter 15 is placed between the display element J-DE and the lens lla in FIG. 4, and between the display element J'-DE and the condensing lens llb in FIG. That's fine.

FIG. 8 is a schematic configuration diagram of a reflective light/lube type projection device as a display device. Luminous flux from the light source 14'±,
The parallel light is made into parallel light through the lens lla, and further, this parallel light is bent at a right angle by the mirror 18 and enters the condenser lens llb. The incident light 14 for illumination collected by the condensing lens l l b passes through the center distance 11 provided at the center of the mirror 19 and is again converted into parallel light by the lens lie, as shown in FIG. 2(B). The reflective display element DE shown
(Here, the heating element layer 10 is excluded). This incident light 14 is reflected by the reflective film 8 of the display element DE, but the reflected light (all or part of it) at a location other than the display point (the heating surface applying heat to the liquid layer heating section 13 or its vicinity) The majority of the light passes through the lens 11c and exits through the central opening of the mirror 19. On the other hand, some of the light reflected at the display point of the display element DE goes out from the central opening of the mirror 19, but it is reflected by the mirror 19,
An image is formed on the screen 12 by the imaging lens l 1'.

Further, the signal light of radiation (mainly infrared rays) 6a modulated through a laser light source and an optical modulator (not shown) is horizontally scanned by a rotating polygon mirror serving as a horizontal scanner 17, and passed through a lens lie as a vertical scanner 16. The radiation is vertically scanned by a galvanometer mirror and is two-dimensionally scanned and incident on the radiation absorption layer 6 of the display element DE. As a result, a large number of display points are formed two-dimensionally within the display element DE in accordance with the signal light, and these display points are formed as bright points on the screen 12 as a projected image as described above. A projected image will be obtained.

Of course, the reflective display element fDE shown in FIG. 2(B) can be used in the display device shown in FIG. 6 as in FIG.

FIG. 9 is a block diagram of a light valve type projection device as a display device according to the present invention.

25 is a video generation circuit that generates a video signal; 24 is a control circuit that controls the video signal and sends this signal to the video amplification circuit 22 and the horizontal and vertical drive circuits 23; 21 is a laser light source; and 2o is a laser The light modulated by the optical modulator 2o, which is an optical modulator that modulates the laser beam from the light source according to the signal from the video amplification circuit 22, enters the horizontal scanner 16 or the vertical scanner 17. Further, the horizontal scanner 16 and the vertical scanner 17 operate in response to drive signals synchronized with the video signals from the horizontal and vertical drive circuits 23, respectively. The configuration of the other portions within the broken line is the same as the configuration described above, and therefore the description thereof will be omitted.

The video signal output from the video generation circuit 25 is sent to the control circuit 2.
4 and is amplified by the video amplification circuit 22. The optical modulator 20 is driven by the input of the amplified video signal and modulates the laser beam emitted from the laser light source 21. On the other hand, a horizontal synchronization signal and a vertical synchronization signal are outputted from the control circuit 24 and drive the horizontal scanner 17 and the vertical scanner 16 via the horizontal and vertical drive circuits 23, respectively. In this way, a thermal two-dimensional image is formed within the liquid layer of the display element DE. The subsequent configuration operations within the broken line are as described above and will be omitted here for simplicity. Note that when receiving TV radio waves, a receiver may be used instead of the video generation circuit 25. As another means for applying a thermal signal to the display element DE, for example, an optical system 26 shown in FIG. 10 is used. In the figure, a laser beam 28 output from a laser oscillator 27 passes through a thin waveguide type deflector 29 and then is not reflected by a galvanometer mirror 30, so that it scans the display element DE surface at high speed. If an image signal circuit (not shown) is connected to the laser oscillator 27,
Concrete image creation becomes n1 capability.

FIG. 11 is a schematic cross-sectional view showing an embodiment of the color display element r- according to the present invention, and for convenience of explanation, the half is a transmissive display element and the lower half is a reflective display element. It is shown by . 6 is a radiation absorption layer, 8 is a reflective film, and in this figure
It is not provided in the transmissive display element DE shown in the halves. 31 is a color mosaic filter, and its specific structure and manufacturing technology have already been published in the Japanese Patent Publication No. 52-t3o.
Since it is explained in detail in 941 Publication and Japanese Patent Publication No. 52-36019, detailed explanation thereof will be omitted here as these are incorporated by reference.

2 is a liquid layer, 3 is a transparent protective plate, and color mosaic filter 3
The yellow elements constituting the display element DE except for 1 are as explained in FIG. 2, and will be omitted here for simplicity.

In the illustrated example, the liquid layer 2 in contact with the red filter part (R) of the color mosaic filter 31 is heated by thermal conduction by the radiation absorption layer 6 that absorbs the radiation 6a, and the liquid layer heating part 13 If generated, is it reflected by the reflection 1198 or the radiation absorbing layer 6? The transmitted parallel illumination light 4 passes through the liquid layer heating section 13, and by the mechanism described above, the liquid layer heating section 1 is heated as shown by the broken line.
The display element D passes through a bent optical path as shown by the two-dot chain line, which is different from the optical path of the light that would have passed if 3 was not present.
E is ejected outside. When white light enters the red filter section (R), the transmitted light or reflected light coming out of the display element DE is light that makes red visible (hereinafter referred to as red light).
Only. The red filter section (
The path of light passing through R) is similar to that described above. B. In this figure, only the light rays from the green filter section (G) that do not pass through the liquid layer heating section 13 are shown.

In addition, when the incident light 4 is white light, the old color filter section (B)
The light that has passed through is only the light that makes blue visible (hereinafter referred to as old color light), and the light that has passed through the green filter section (G) is the light that makes green visible (hereinafter referred to as green light). ) only. When viewing the display element DE in the direction of the light passing through the liquid layer heating section 13, an observer (not shown) sees pseudo-color by the additive coloring method.

For example, when the liquid R2 is simultaneously heated in the red filter part (R), green filter part (G), and old color filter part (B) of the adjacent color mosaic filters 31, the liquid layer heating part 13 is formed. , an observer (not shown) can see white.

Furthermore, as explained in FIG. 2, by arranging a light shielding grating (not shown) in front of the display element fDE, some of the light emitted from the display element DE passes through the liquid layer heating section 13. By passing only the incoming light through an aperture of a light-shielding grating (not shown), a clearer pseudo-color display using the additive coloring method can be obtained.

Figure 12 shows a simultaneous color light/lube type projection device with three channels of red, blue, and green.
．． 34 are arranged in parallel and projected onto the screen 12 at the same time,
This is a method in which rasters of three primary colors are neatly superimposed on the screen 121-. As shown in FIG. 13, white light T1.14'' is separated into the three primary colors by two microink mirrors 35 and 36, and each of the J' devices throws red, blue, and green. This is used as a light source for illumination.Therefore, the luminous flux utilization rate of the light source is approximately three times that of a sequential type.

FIG. 14 is a schematic sectional view of another display element according to the present invention, FIG. 14(A) is a transmissive type, and FIG. 14(B)
1 and 2 respectively indicate reflective display elements.

In the figure, 3 indicates a transparent protection plate (which may not be used when display element DE is used horizontally), 2 indicates a liquid layer, and these have the same functions as those explained in Fig. 1. is an element. 40 is a thermally conductive insulating layer, on both sides of which a plurality of heat generating resistance wires 41, 42 as heat generating members are arranged two-dimensionally in a matrix shape so as to intersect with each other sandwiching the insulating layer. be. 5 is a substrate serving as a support plate for these heat generating resistance wires 41 and 42 and the insulating layer 40. Figure 14 (
In the case of the transmissive display element DE shown in A), the heating resistance wires 41, 42, the plate 5, and the insulating layer 40 are transparent. For example, the heating resistance wires 41 and 42 are made of transparent thin film 1 made of indium tin oxide. It is composed of patterns. In these display elements DE, a predetermined heating resistance wire 4
The design is such that only when either 1.42 or 1.42 is selected and heat is generated, a liquid layer heating portion (not shown) of a high temperature region that can be displayed in the liquid layer 2 is formed in the intersection area of the two.

In addition, as described above in FIG.
, the reflective film 8 is used as necessary.

Next, an example of matrix driving of such display elements will be described in more detail with reference to FIG.

In the figure, DE indicates a display element, which will be explained in FIG.
You can think of it as having the same detailed structure as the one. This display element DE has a height of X and a height of X m.

The heating resistance wires of the material shafts of X n , X o , and X p (
These are made up of row lines (IIJ) and Yc, Yd, Ye (external heat generator) Ala (these are called column lines), etc., and one of the column lines Yc, Yd, and Ye is connected to a common DC power supply. The other terminals are connected to the collector sides of transistors TrI-'Tr3 whose emitters and terminals are grounded, respectively.

Row lines X e , X m , X n , X o ,
X p for heating '11! , when a flow pulse is applied, the liquid layers (not shown) corresponding to these row lines are sequentially heated in a linear manner, but at this time, the degree of heating is set to be below the threshold of 16 in the liquid heating display. Therefore, a liquid layer heating section 13 in a high temperature region for heating display is not generated in the liquid layer. On the other hand, in synchronization with the application of the heating current signal, a video signal pulse is applied to the base sides of the transistors Tr, -Tr3 arranged on the emitter side, and connected to these transistors TrI -'rr3, respectively. Column line Yc
, Yd, and Ye are applied with predetermined video signals. By applying this video signal '-J, the column conductors Yc, Y
The liquid layers corresponding to d and Ye are linearly heated. As a result, at the intersection of the row line and the column line where the heating current pulse and the video signal k are synchronized, the heating current pulse is additively heated by the A heat of both, and the degree of heating of the liquid layer becomes the threshold for heating display. If conditions are set so that a liquid layer heating part 13 is formed in the liquid layer, which corresponds only to the case of additive heating, the intersection of the row line and the column line selected by one A liquid layer heating section 13 is formed in the.

Incidentally, in the above example, even if the driving method is changed as follows, side images can be formed in exactly the same way. That is, even if a modification is made in which a video signal is applied to the row lines and a heating current signal is applied to the column lines, the effect is exactly the same. In this way, the display element DE illustrated in FIG. By installing the heat-generating resistance wire on both the transparent protection plate side and the substrate side, the following effects occur.

Mountain: The first stage of manufacturing becomes easier and the yield rate improves.

2-inch Thermal efficiency is good because the liquid layer is heated from both sides.

It is a hat.

It is desirable to separately provide a heat sink to enhance the heat dissipation effect of the heat generating resistance wire. This heat sink has a board 5 (Fig. 14).
It is possible to substitute The aforementioned row lines and column lines are separated by an insulating layer 40, and the thickness of the insulating layer 40 is several microns, so if both signals are applied simultaneously due to the time lag in heat conduction, the liquid layer 2 At the same time, since the conductive heat does not arrive, the formation of the liquid layer heating section may be inhibited.

Therefore, in order to further enhance the additive heating effect, it may be preferable to delay the applied pulse to the signal line closer to the liquid layer 2 than the signal pulse to the other signal lines. Note that it is not necessary that all of both signal lines be formed of heating resistors. Rather, it is much better to construct only the intersection of row lines and column lines with a heat-generating resistor, and to construct the rest with a good conductor such as AL; However, the drawback is that the manufacturing process becomes more complicated.

Another example of a heat generating element as a heat generating element for configuring a display element suitable for performing mud 1 run driving as shown in FIG. 15 will be explained with reference to FIG. 16.

FIG. 16 is an external perspective view schematically depicting a partial area of the heating element. In figure 9, 45 indicates a heating resistance layer,
Although not shown in the figure, this resistance layer 45 is obtained by forming a planar film of a known heating resistor (for example, nichrome alloy, boride/fnium, nitride/tal, etc.). Of course, it also extends to the lower blade in the drawing. Also, 46a, 46b,
46c.

46d are column conducting wires, 47a and 47b.

47c are all row conductors. All of these conductive wires are made of good conductors such as gold, silver, copper, aluminum, etc. (Although not mentioned, the conductive wires are generally covered with an insulating film (not shown) such as 5i07. It is.

). In the illustrated heating element, for example, when the column conductor 46b and the row conductor 47c are selected and a voltage is applied to them, the resistance layer 45 corresponding to the intersection 48 of both is selected.
Electricity is applied to a part of the unit, which generates heat.

In this way, any (row/column) intersection of the row conductor and the column conductor can be heated.

Therefore, the heating element shown in FIG.
In the display element incorporated in place of the heat generating element consisting of the heat generating element 2 and the insulating layer 40, it is possible to display a tonto matrix image using a matrix drive system similar to the example shown in Fig. 15. .

Incidentally, in the heating element shown in FIG. 16, the heating resistance layer 45 may be divided and provided only at the intersection of the column conducting wire 46 and the row conducting wire 47 (the conducting wires may be insulated from each other in other areas). This is possible, and in such a configuration (Fig. 17), there is a loss i-- which is inconvenient for image formation faithful to the signal.
It is possible to substantially prevent the occurrence of this problem.

In the example of FIG. 17, the row conductors 47a, 47b...
(hereinafter referred to as the 1-row conductor 47) and the column conductors 46a, 46b...
(hereinafter referred to as column 4 line 46) is Sin.

Although they are disposed through an insulating film (not shown) such as Si3N, 1, etc., the insulating film in the intersection area of the row conductor 47 and column conductor 46 is removed, and instead, heating resistors 45a, 45b,
... (hereinafter referred to as heating resistor 45) is embedded.

Next, in FIG. 18, the heating element as the heating element shown in FIG. 17 is replaced with the heating resistor 41 shown in FIG.
An example in which a display element incorporated in place of the heat generating element composed of the heat generating element 42 and the insulating layer 40 is driven in a matrix manner will be described in more detail. Nail shaft selection circuit 103 Bar shaft drive circuit 10
1a, 101b... (hereinafter referred to as the 2nd row axis drive circuit 101) and are electrically coupled by the signal '-'f wires)
Furthermore, each output terminal of each material shaft drive circuit 101 is coupled to a respective row conducting wire 47. There are various ways to connect the output terminals and the row conductors 47, but in this specification, in order to explain the basic method, there are as many output terminals R- as there are M1 conductors 47, and there are two output terminals. Suppose that is connected to the row conductor of .

! JIII1111 additional circuit 104. Tally shaft drive circuit 1
02 a.

102b, . . . (hereinafter referred to as the dynamic shaft drive circuit 102) and the Taly conductor 46.

The image control circuit 105 is electrically connected to the nail axis selection circuit 103 and the nail axis selection circuit 104 by signal lines. The image control circuit 105 outputs an image control signal to instruct the rod shaft selection circuit 103 to select the nail shaft, and the same applies to the outer shaft selection circuit 104 with +kJL. That is, in response to an image control signal from the image control circuit 105, the nail shaft selection circuit 103 selects (switches on) a specific row (row 1!) via one of the wood shaft drive circuits 101. For example, When the nail shaft selection circuit 103 selects the row conductor Xp, it issues an Xp row selection signal, and in response, the rod shaft drive circuit 102Xp inputs a rod shaft drive signal also to the row conductor Xp.On the other hand, the image control When a video signal, which is one of the image control signals from the circuit 105, is manually input to the outer axis selection circuit 104.

Upon receiving the command, the outer axis selection circuit 104 selects a predetermined outer axis (column conducting wire). For example, if the moving axis selection circuit 104 selects the column conductor Ye, the moving axis drive circuit 102Ye receives the Ye column selection signal issued from the outer axis selection circuit 104 and selects the column conductor 1. Turn Ye into swift on (conducting) state.

If the selection of the line conductor and the selection of the outer axis are carried out cyclically, If, in this example, the intersection point of the row conductor Xp and the column conductor Ye (selection point;
A current flows through the heating resistor located at p-Ye), generating Joule heat, and forming a liquid layer heating portion in the liquid layer (not shown). A flow also flows to the leak 1 at the non-selected point, but since the current value is less than the current value for forming the liquid layer heating line, no liquid layer heating portion is formed in the liquid layer.

Further, by providing the heating resistor 45 with a diode function, the leakage 1rL flow can be made even weaker.

In this way, in the same way as explained in FIG. 15, in FIG. 18 as well, line-sequential scanning is performed using a single rod axis drive signal, and an outer axis selection signal is output in synchronization with the scanning.

Two-dimensional image display can be performed by bringing selected column conductors 46 into a conductive state via the outer shaft drive circuit 102. The moving axis selection circuit 104 outputs an outer axis selection signal in response to a command from the video (i''3).

At this time, the direction of the current flowing through the heating resistor does not matter. Such row and moving axis selection circuits 103, 104 and rows,
The outer shaft drive circuit 102 is constructed using a known technique using shift transistors, transistor arrays, and the like.

In addition, even in the matrix-driven display method using the heating element described below, the transmission type table 21' shown in FIG. 14(A) as shown in FIG. 2(B) and described above. <It is also possible to use the pressure absorbing film 9 in the element DE, and the first
4. Also in the display element DE having the configuration shown in FIG. By interposing a corrosion-resistant silicon oxide film or silicon nitride film in the liquid layer 2, reaction corrosion between the liquid layer 2 and these can be appropriately prevented.

Further, the red filter part (R), green filter part (G), and blue filter part CB) of the color mosaic filter shown in FIG. In the display element DE shown in the figure, the intersection of the heating resistor wires 4 and 42, and in the heating element shown in FIG. 17, the part of the heating resistor 45)1
- By arranging and providing the 11th
By adopting a configuration similar to the example shown in the figures, a display element using the heating elements shown in FIGS. 14 and 17, respectively, can be obtained.
Of course, color display can be performed using the same principle as in FIG. 11.

However, in a light valve type projection device as a display device using a display element using such a heating element, the portion related to the radiation input means as shown in FIG. 7 or FIG. , a laser light source and a light modulator (not shown),
Of course, rotating polygon mirrors, galvano mirrors, lenses, etc. are unnecessary. Of course, it goes without saying that such a matrix-driven display element can also be applied to the light valve type projection apparatus shown in FIGS. 3 to 6.

FIG. 19 is a schematic partial diagram of another modified example of a heating element as a heating element. The arrangement of the heat generating parts in the heat generating element 5 in Fig. 14 is in the form of a planar dot matrix (dot matrix), whereas the heat generating part of the heat generating element 5 in this figure is arranged in a dotted line (dot matrix).
They are arranged in a dot/line pattern. 49 is a heating resistor, which is connected alternately with the insulating layer 51b on the line a-a'.
arranged in the direction. Electrodes 50a and 50b are provided on both sides of this heating resistor 49, respectively. This electrode 50
The a side is commonly connected and grounded. The other electrode 50b side is connected to the electronic switches of the switching circuit 51a. This 'electronic switch'
・The ends are commonly connected to a DC power supply (not shown). It is assumed that the electronic switches of each of the switching circuits 51a(r) are opened and closed in accordance with the image signal.

FIG. 20 is a schematic configuration diagram of a display device that projects a color image onto a screen using the heating element shown in FIG. 19.

57r, 57g, and 57b are a red light source, a green light source, and a six-color light source that output red light, green light, and blue light, respectively, and emit light alternately in time series in this order.

56a and 56b are half mirrors, each with a green light source of 57g.
, the light from the blue light source 57b is reflected to produce red light 9.57
This is for directing the light in the same direction as the r light. 5
Reference numeral 5 denotes a line image optical system composed of a cylindrical force lens 54, etc., and lines a-a', 1 on the heat-generating part of the reflective display element DE incorporating the heat-generating element 51 shown in FIG. 19 as a heat-generating element. ．． This is for forming an image of any one of the red light source 57r, the green light source 57g, and the blue light E57b in a line shape. If a liquid layer heating part is not formed in the liquid layer of the display element DE, the line-shaped optical image formed on the display element DE, h will be reflected by the display element DE, and all of it will be reflected by the line image forming optics. By system 55, display element DE
The light is focused on the light shielding filter 7 CJ2 through the light shielding filter 7CJ2. 52 is a lens, 53 is a Carpano mirror as an example of a light deflector, and 58 is a lens, by which light scattered from the liquid layer heating portion of the display element DE is imaged on the screen 12. Further, the galvanometer mirror 53 is for scanning an image corresponding to the line image reflected from the display element DE in the direction of the arrow on the screen 12.

Assume that the galvanometer mirror 53 is now located at a certain position.

The red light from the red light source 57r is imaged into a line on the display element DE by the line image forming optical system 55. In synchronization with this, the heating resistor 49 of the heating element 1'-51 of the display element DE
is energized via the switching circuit 51a in response to a video signal to generate heat, and a liquid layer heating portion (not shown) is formed in the liquid layer of one display element DE. The red light scattered by the liquid layer heating section is imaged as a point image on the screen 12- through the lens 52, galvano mirror 53, and lens 58. For the next green light source and blue light source, a line image consisting of a point image corresponding to the video signal is received on the same line on the screen 12 by the same operation as for the red light source. In this way, if line images are formed on the screen 12 by scanning the galvanometer mirror 53 one after another, a color projected image corresponding to the video quality will be formed on the screen 12-.

In addition, in the embodiments from FIG. 14 to FIG. 20, when a liquid with good conductivity such as alcohol is used as the liquid of the liquid layer, as explained in FIG.
When using the heating element shown in Fig. 19 as a display element and not using a reflective film, it is necessary to
Needless to say, a thin insulating layer such as 07 may be interposed. Further, when using the conductor reflection j1 as the reflection III, it goes without saying that a thin film of an insulating layer of 5i02 shades is interposed between the first reflection film and the heating element.

FIG. 21 is a diagram of a liquid circulation system of a display device for cooling a liquid layer of one display element. Display element DE
When driven continuously for a long time, the liquid layer 2 in the element DE
gradually warms up by +1 due to heat accumulation, and vapor bubbles may suddenly occur in the liquid layer 2, which has 76 layers of liquid.

If the amount of heat storage increases in this way, it will cause noise, which is not desirable.

Therefore, in this example, in order to prevent heat accumulation in the liquid layer 2, the liquid in the liquid layer 2 is circulated between the display element DE, the vaporization chamber 63, and the Rtt conversion chamber 64.

The role of the vaporization chamber 63 is to remove such surplus heat as heat of vaporization, and to absorb or alleviate the pressure caused by the unexpected generation of vapor bubbles. Further, a pressure reducing means 62 is added to the vaporization chamber 63 in order to maintain it in a predetermined reduced pressure state.

If the pressure in the vaporization chamber 63 is lower, the rate of evaporation of the liquid will increase, so the rate of heat dissipation will be faster, which is another effect of the pressure reduction means. The vaporized vapor is then liquefied by releasing heat outside the system in the liquefaction chamber 64, and is again injected into the liquid layer 2 within the display element DE through the circulation path 65.

Therefore, while maintaining the reduced pressure state by the pressure reducing means 62, the liquid layer 2 passes through the circulation path 65 to the vaporization chamber 63, from this vaporization chamber 63 to the liquefaction chamber 64, and then from the liquefaction chamber 64 to the liquid layer 2. The liquid circulation system that circulates liquid is effective in firstly removing thermal noise as an image defect, and secondly in removing pressure-induced noise.

Furthermore, by providing the display element DE with a cooling means 61 consisting of a heat dissipation means or a Peltier effect element, the diagonal effect can be promoted.

An enlarged screen can be projected onto the aforementioned screen.

By the way, the liquid circulation system described in this figure does not require the intervention of a forced liquid circulation device such as a pump. In other words, a liquid circulation system can be constructed by overnight natural convection.

In addition, when flowing the liquid of the liquid circulation system into the liquid layer 2 during the period of forming the liquid layer heating section, it goes without saying that the flow rate should be set to a level that does not disturb the liquid layer heating section.

Further, the pressure reducing means 62 can be constructed using a vacuum pump or an electromagnetic valve f, and a fan may be provided on the outer wall of the liquefaction chamber 64 for the purpose of promoting heat radiation.

Furthermore, if we call the time from when a heat pulse is applied to the liquid to when a liquid layer heating portion (not shown) is formed in the liquid layer 2, the standing time is 10 μsec. , l)
On the other hand, if we call the time during which this liquid layer heating section disappears or disappears, the fall time is 301i, set.
The rise time and fall time depend on the liquid temperature in layer 2, pulse application time, applied voltage, heat radiation conditions, etc., and are also susceptible to the specific heat and thermal conductivity of the liquid. cannot be argued. However, from the viewpoint of afterimage effects, etc., the fall time is not required to be very fast. The desired fall time can be set by adjusting the composition of the liquid.

The lower the specific heat of the liquid constituting the offshore layer 2, the more advantageous it is because the liquid layer heating section can be easily formed with lower power consumption.

For example, methyl alcohol (boiling point 65°C9 specific heat 0.59
9 cal/g-deg at 20″c)1.=
c-Tyl alcohol (78℃, 0.58 cal/g
temperature at 25°O), n-propyl alcohol (
97℃, 0.58ft cal/g-deg a
t 25℃), isopropyl alcohol (also 2℃,
0.569 cal/g” deg at 20°C)
, n-butyl alcohol (118°C1 0.563
cal/go deg at 25℃), - Kisa〉(same at 126℃, same o,, sos cal/g @
deg at 25°C), Henze〉' (also at 0°C
, 0.25 cal/g・deg a125°C), toluene (110'O, 0, 269 cal/g・d
eg, vt 25°C), xylem〉' (144, 0, 387 cal/g・degat 30°C
), 4J1! ) μ element (77°C1 0.207
cal/g-deg at 20°C), ethylene glycol (0.5619 cal/g at 198°C)
deg), glycerin (290°C, 0.568
If the liquid layer 2 is composed of a liquid (whether alone or in combination) such as cal/g-(leg), water (boiling point 100°C
, specific heat 1 cal/g degree) A much better result in display contrast can be obtained than in the case of the liquid layer 2 composed of m-soles. Therefore, a suitable specific heat condition is a temperature of 20
Q. at ~25°C. It is more than 7 cai/g・deg. For the same liquid, the higher the temperature of the liquid layer heating section is compared to the surrounding area, the higher the display contrast becomes.

However, methyl alcohol, ethyl alcohol,
iJ of carbon tetrachloride, etc. With boiling point solvents, the temperature cannot be raised too high because bubbles will occur if the temperature is raised.

This is the reason why the display contrast cannot be lowered. On the other hand, high boiling point liquids such as ethylene glycol and glycerin do not produce vapor bubbles even if the temperature is increased by heating them, so the temperature gradient of the heated liquid can be widened and the display contrast can be increased. It is +7J ability to do. In experiments, good display contrast tests were obtained for liquids with a boiling point of 8.0'C or higher. For example, isopropyl alcohol is one suitable example.

In addition to this, the present invention can also display colors by dissolving dyes in the above-mentioned type of liquid of the liquid layer used in the display element and using the liquid layer that exhibits various colors. For example, C.I. 1. Tiref Trend 3, 16, 20, 44, 54, 55
, 75, 77, 81, 83, 1Ol, 11
0, 152, C. 1. Acid Rent 1, 3, 5
, 8, J2, 17. Times 19, 22, 31, 32, 37, 41, 47, 56, 60, 7
1, 112, 115, 154, 155, 16
0, times 171, times 187, C. 1. Asianren F Noheiore I 5, 7, 11, c. r. There are 6, 7, and 161. C is a dye that uses a liquid that produces a yellow color.

■． GuiRect Yellow 18, 22, 21, C. 1
．． There are Ashi, Toyello 1, 13th, 18th, 106th, 186th, etc. As the dye used for static bodies that develops cyan color, C.I. 1. Direct Blue-1, 37, 83
, 127, 149, 215, 231, C. 1.
Examples include Acid Blue 15.

However, even if the liquid constituting the liquid layer is colored by appropriately selecting a dye as described above, the principle of image formation of the display element as described above in FIG. 1 remains the same. Therefore, when the liquid layer is colored, a single color image can be displayed.

Furthermore, when the liquid layer heating section is formed in the liquid layer (if the viewing eye is brought close to the display element f-, the light passing through both parts enters the viewing eye and can be seen at the same time). ), since the non-heated part of the liquid layer is more strongly colored than the heated part of the liquid layer, an image can be displayed depending on the degree of coloration.

Therefore, for a display element using such a dye in the liquid layer, the image of the display element may be projected onto a screen using a light valve type projection device as described above, but it is also possible to use an imaging optical system to project the image of the display element onto a screen. The image can be displayed even if the image is directly projected onto the screen l-.

As explained in detail in Section 2 below, the main advantages of the present invention are (1) that it is possible to arrange one of the m-small liquid layer heating parts in a high-density arrangement as a unit of display pixel; , can display high-resolution images.

(2) By adjusting the duration time in the liquid layer of the liquid layer heating unit as 9 display pixels, the remaining time 11111 or
You can easily display videos including slow motion.

(3) By employing a liquid circulation system in the three display elements, it is possible to present a screen of good image quality without noise.

(4) Multi-color display and full-color display can be easily implemented.

(5) Since the structure of the device is relatively simple, its productivity is excellent, and the device has high durability and reliability.

(6) Can be adapted to a wide range of drive systems.

(7) Since the display is performed by heating the liquid layer to a temperature below the boiling point rather than by forming base bubbles, less power is required for the display element r-, and the power supply section, that is, the display element The display device can be downsized.

(8) In element r, which performs light modulation and display using M bubbles, there is a risk of damaging the display element r- due to gearvitation when non-bubbles disappear, but in the present invention, the liquid layer is not simply boiled. Since the heating is done only to a certain degree, the ml durability of the element is very high.

(9) When displaying with vapor bubbles, the liquid in the liquid layer is removed, leading to an increase in pressure, and a special liquid discharge location must be provided for this purpose, but in the case of the present invention, the increase in pressure is related to the liquid layer. Since the heat of the liquid is only 11 tensile, it hardly causes an increase in pressure, so there is no need for pressure countermeasures, or even if countermeasures are provided, the display element itself can be miniaturized with only a pressure absorbing film. , and repeatedly.

It is less affected by pressure and is durable in use.

(10) Since the contrast of the display depends on the degree of heating of the liquid in the liquid layer, it is easy to display halftones in an analog manner.

[Brief explanation of the drawing]

FIG. 1(A) is a schematic cross-sectional view for explaining the image forming principle of a transmissive display element according to the present invention, and FIG. FIG. 2 is a schematic cross-sectional view of a specific display element according to the present invention, and FIGS. 3 to 8 are schematic cross-sectional views of a display device as an application example of the present invention. 9 is a block diagram of a display device as an application example of the wooden invention; FIG. 10 is an external perspective view of an example of an input system for imaging signals using radiation;
Figure 1 is a schematic sectional view for explaining an example of the configuration of a color display according to the present invention, Figure 12 is a schematic configuration diagram of a color display device as an example of the application of the wooden invention, and Figure 13 is a diagram of a color illumination optical system. A schematic configuration diagram, FIG. 14 is a schematic sectional view for explaining a configuration example of a matrix-driven display element according to the present invention, and FIG. 15 is a schematic explanatory diagram of an example of an image forming method according to the present invention. 16 and 17 are external perspective views for explaining each configuration example of a heat generating element, FIG. 18 is a block diagram of a matrix and matrix drive display device according to the present invention, and FIG. ``A schematic partial diagram of the line-shaped heating element f, etc., Figure 20 is,
FIG. 21 is a schematic diagram of a liquid circulation system used in the display element of the present invention. ]・Heating element 2・Liquid layer 3 Transparent protection plate 4: Illumination light 5: Substrate 6: Radiation absorption layer 6a: Radiation 7: Grating 7a: First grating 7b, second grating 7c, ? d:
Light blocking filter 8: Reflection 11Reflection 9 Pressure absorption film
10: Heating layer 11 Schliere/Lens
11': Yui f! Lens 11a: Lens 1
1b=Condensing lens 12 screen 13: Liquid layer heating section 14: Used light 14': Light source 15
:Cold filter 16. Vertical scanner j7: Horizontal scanner 18: Mirror 19: Mirror
20: Optical modulator 21: Laser light source 2
2: Video amplification circuit 23: Vertical drive circuit, horizontal drive circuit 24: Video control circuit 25: Video generation circuit 26:
Optical system 27: Laser oscillator 28/laser beam 28: Thin film waveguide deflector 30: Galvano mirror 31: Color mosaic filter 32: Red channel projection device 33: Green channel projection device 34: Blue channel projection device 40: Insulating layer 41 .42: Heat generating resistance wire 4
5: Heat generating resistance layers 48a, 411b, 46c, -: Column conductors 47a, 4
7b, 47c, ...=: Row conductor 48 two intersections
48: Heating element 50a, 50b,: Electrode
51: Linear heating element 53 Nigal pano mirror 54 Nijilintorical lens 55: Linear image forming optical system 57r: Red light source 57g:
Green light source 57b: Blue light source 61: Cooling means
62: Pressure means 63: Vaporization chamber
64: Liquefaction chamber 85: Circulation path 1019 Row axis drive circuit 102: Dynamic axis drive circuit 103: Nail axis selection circuit 104 Column axis selection circuit 105: ση image 11
ノ Controlling 胛 1 path DE: display element r ′lν disappearance Nt 1 person Cano ′L/+ Zhu Shikikai n (ni (A) (B) th
1 Figure 2 Figure 4 Flash 5 Figure 10 Flash 32 Figure 13 Figure 14 (Foundation) 1b No. 2 Canon Co., Ltd. -766-

Claims (1)

[Claims] (+) A liquid layer made of a liquid that is transparent to visible light and a heating resistor arranged in a dot matrix or dot line shape to change the physical properties of the liquid layer. and a display element having a heating element for heating the liquid layer to an extent that boiling does not occur in the liquid layer, and a driving means and signal for manually applying a signal according to image information to the heating element of the display element. A display device characterized by comprising a scanning means, an illumination optical system that illuminates the display element f, and an imaging optical system that projects image information of the display element onto a screen. (2) The illumination optical system comprises a Schlieren optical system using a filter or a grating r. which transmits or reflects light in the heated or non-heated part of the display element.
The display device described in section 1).