JP2673348B2 - Planar light emitting device - Google Patents

Description

The present invention relates to a planar light emitting device suitable for displaying characters and images. [Prior Art] Examples of conventional thin light emitting devices (displays) include liquid crystal displays, plasma displays, electroluminescent displays, light emitting diode displays, and the like. [Problems to be solved by the invention] Character and image displays have become more important man-machine interfaces in the information age, and high quality,
Diversification is progressing. One of the characteristics required for a display for an information processing device terminal is high definition and improved visibility. The former corresponds to high-density information display, and the latter corresponds to an ergonomic viewpoint (easy identification, eye strain prevention).
Is important from. Among small displays of 20 inches or less used as terminal devices, there is a cathode ray tube display as a device that most surely satisfies these required characteristics. Cathode ray tube displays have long been widely used in moving homes as moving picture display devices (televisions), but improvements in high definition, flicker prevention, high contrast, etc. for information processing terminals (for still images) have been improved. It's peeled off. However, since the cathode ray tube utilizes the phosphor excitation phenomenon by a high-speed electron beam, the high voltage (-10KV) and depth (several tens of centimeters) required for electron beam acceleration are the obstacles to "usability". In addition, the weight of the device, including the step-up transformer and deflection yoke, is more than several kilograms, so the compatibility with electronic devices that are light, thin, short, and small is gradually deteriorating. Therefore, various so-called flat displays have been developed as display devices that compensate for this drawback.
Some liquid crystal displays, plasma displays, fluorescent display displays, electroluminescent displays, light emitting diode displays, etc. have been put to practical use. Of these, the devices other than liquid crystal displays are self-luminous devices, but the luminous efficiency (electricity to light energy conversion efficiency) is 0.01-0.1%
There is a big problem that it is lower than 2-3% of cathode ray tube display by one digit or more. On the other hand, liquid crystal displays have the advantages of low driving voltage, extremely low power consumption, and little eye strain because they do not emit light, but they cannot be used in the dark, have a visual angle dependency, and have a low contrast ratio. Have a problem with. Therefore, in recent years, a liquid crystal display with a back light has been developed, and a color television in combination with a color filter has come on the market. Compared with the cathode ray tube display, the above-mentioned flat panel display is thin and light, and in addition to the fact that information is displayed in an XY matrix, it is easy to see without blurring or flickering especially in the case of a still image. From the above-mentioned characteristic needs for displays for information processing terminals and the current state of electronic display devices, it is a self-luminous device with high luminous efficiency and high contrast and high color rendering properties as in a cathode ray tube display, and as thin as a color liquid crystal display. There is a demand for new display devices that are light and easy to see. It is an object of the present invention to overcome the drawbacks of the current display devices described above and to disclose a new device that combines the advantages of cathode ray tube displays and flat panel displays. [Means for Solving the Problems] In order to achieve this object, in the present invention, an optical shutter layer is provided in the vicinity of the upper surface or the lower surface of the photoexcitation phosphor layer that is excited by ultraviolet rays of a constant intensity irradiated from the lower surface side. Disclosed is a planar light emitting device in which the optical shutter layer is driven by a predetermined information signal to control the intensity of light emitted from the photoexcitation phosphor layer and is externally displayed as a light image. In order to make the planar light emitting device a liquid crystal display with a backlight and a thin type, a thin light scattering chamber is provided on the lower surface side of the photoexcitation phosphor layer, and a straight tube ultraviolet lamp disposed on the side surface of the planar light emitting device is used. The device structure may be such that the emitted excitation light is once guided to the light scattering chamber to be scattered light of uniform density, and the scattered light excites the phosphor layer located above. The optical shutter layer is preferably of a type that uses the entire plane of polarization of transmitted light (this corresponds to Example 1 in which a polarizing plate is not used) from the viewpoint of improving the efficiency of electricity-to-light energy conversion. Further, the phosphor region, which is a light emitting portion of the photoexcitation phosphor layer, is preferably sealed in a vacuum state from the viewpoint of stably maintaining highly efficient light emission for a long period of time. [Operation] In the present invention, the emission intensity from the phosphor layer is controlled by controlling the optical shutter layer. [Examples] FIG. 1 is an external view of a planar light emitting device of the present invention. The planar light emitting device has a structure in which a planar light emitting layer 1 and a light irradiation unit 2 are stacked. The light irradiation unit 2 includes an excitation light scattering chamber 11 and straight tubular ultraviolet excitation light sources 3 and 4. RGB separated by a black matrix on the planar light emitting layer 1 side of the excitation light scattering chamber 11
The phosphor layers are arranged, and the ultraviolet rays emitted from the excitation light sources 3 and 4 collide with the RGB phosphor layers to fluoresce the entire phosphor layer. The planar light emitting layer 1 has an optical shutter layer corresponding to all the RGB layers on the phosphor layer in a one-to-one correspondence. For example, RG
If the number of B is n × m, the optical shutter layer has n × m individual optical shutter layers. The individual optical shutter layers are horizontal,
The vertical synchronizing signal S is used to switch over one after another, and the amount of light corresponding to the size of the video signal (gradation signal) is transmitted.
Therefore, the fluorescence from all the RGB dots in the phosphor layer is
The individual shutter layers are selected one after another, and planar light emission is performed from the upper surface of the planar light emitting layer 1. Here, the video signal is an image signal forming a video screen. The size of one screen of the video screen is the planar light emitting layer 1
The size of. However, it may be smaller than the planar light emitting layer 1. The size of the video screen and the size of the planar light emitting layer 1 are determined by what is displayed and what display form is used. The second is an external view in which only the light irradiation part 2 is extracted from the drawing.
Shown in the figure. The excitation light scattering chamber 2 is hollow and has excitation light sources 3 and 4 on both sides. The excitation light sources 3 and 4 excite the ultraviolet light sources 5 and 6 under the voltage application from the sockets 7 and 8 to generate ultraviolet light. This ultraviolet light is condensed by the condenser lenses 9 and 11 and enters the scattering chamber 11. In the scattering chamber 11, ultraviolet light is scattered and collides with the phosphor layer to generate fluorescence from each RGB dot. This fluorescence is selected by the shutter function in the planar light emitting layer 1 and becomes a planar light emitting source. The planar light emitting layer 1 has a liquid crystal layer inside and selects transparent or opaque depending on the state of voltage application to the liquid crystal layer.
There are many gradation states between transparent and opaque. This selection becomes the shutter function. FIG. 3 shows the principle of operation of the individual planar light emitting layers of the planar light emitting layer 1. The individual planar light emitting layer 1A is one of RGB
It corresponds to dot 2A and is switched by the synchronization signal S.
12 is turned on, and the video signal Vin at that time is supplied to the individual planar light emitting layer 1
Apply to A. The video signal Vin is a 1-dot video signal and has multiple gradations. Note that the planar light emitting layer 1 has n × m individual planar light emitting layers, which are formed in a matrix and have a synchronization signal S
The scanning is switched one after another by. Specific examples will be described below. Example 1 A 5-inch light emitting display device for image display was constructed as follows. That is, as shown in FIG. 4, the display device includes the excitation light scattering chamber 11, the color phosphor layer 3
0, a rectangular display face plate having a structure in which a liquid crystal light shutter layer (planar light emitting layer) 1 is laminated in this order, and a linear excitation light source provided in close contact with a pair of parallel side walls facing each other of the excitation light scattering chamber.
It consists of 3 and 4. The rectangular display face plate has an outer periphery made of glass, and has a size of 3.5 (inch) × 4.5 (inch) × 0.8 (inch thickness). Of these, the display area is 3 (inch) ×
It is 4 (inch). In the excitation light scattering chamber, the walls of the linear excitation light sources 3 and 4 in close contact are covered with the condenser lenses 9 and 10, and the upper surface is covered with the glass substrate 19 coated with the color phosphor layer 30 on the inside. The wall surface (two side surfaces and the bottom surface) is composed of a hollow rectangular parallelepiped covered with a glass plate 15 on which an aluminum reflective thin film 16 is vapor-deposited, and the inside is in a vacuum state. On the other hand, the color phosphor layer 30 includes the transparent glass substrate 19
It is composed of an island-shaped phosphor region 18 coated on the above and a non-emissive black tomalix region 17 separating each phosphor island. The width of the non-emissive black matrix is 50 μm in the vertical direction (3 inches in length) and 40 μm in the horizontal direction (4 inches in length), and is formed by screen printing of carbon paste. After forming the black matrix, the island-shaped phosphor regions 18 are formed using a mask pattern, but for full-color display, R (red), G (green), B
Phosphors of respective colors (blue) are arranged in the pattern shown in FIG. R.
GB Each phosphor has a well-known phosphor material, such as Y ₂ O ₂ S: Eu for red, Zn ₂ SiO ₄ : Mn for green, and BaMg ₂ Al for blue.
₁₆ O ₂₇ : Eu is used. The area of each phosphor island (segment) is 200 μm (vertical direction) × 250 μm (horizontal direction). The portion of the glass substrate 19 protruding from the display surface (3 inches x 4 inches) has a folded shape with a thickness of about 5 mm as shown in Fig. 4, and the inner surface of the folded portion becomes opaque by sandblasting. There is. This part serves as the ceiling support part of the hollow excitation light scattering chamber 11 described above, and serves as the excitation light scattering chamber.
Welded with 11 exterior walls. Therefore, the island-shaped phosphor layer 18 is in a state of hanging in a vacuum. In FIG. 5, RGB are regularly arranged, and any of RGB is similarly arranged in a blank portion where RGB is not displayed. Now, the liquid crystal optical shutter area 1 is the transparent glass substrate 19 described above.
The ITO film 20 formed on the back surface of the liquid crystal and the liquid crystal alignment film 26, the liquid crystal layer 28, the upper liquid crystal alignment film 22, the spacer 21, the upper ITO film 23 to which the upper liquid crystal alignment film 22 is adhered, and TFT
(Thin film transistor) Drive display electrode region 25. This area has a shutter function to reverse the liquid crystal to transparent-opaque. That is, in the shutter, only the upper ITO film (display electrode) 23 of the two ITO films 20 and 23 sandwiching the liquid crystal layer 28 is matrix-arranged in an island shape as shown in FIG. Is driven and the time in the “open” state is controlled to allow fluorescence to pass through from below, thereby displaying a full color image. Since the time of the "open" state is controlled, halftone display is possible, of course. The area of the island-shaped display electrode 23 is
It is 210 μm (horizontal direction) × 160 μm (vertical direction), and the intervals are 40 μm in the horizontal direction and 35 μm in the vertical direction. A TFT is used to apply a voltage to the display electrode 23 for a time commensurate with the signal. For example, amorphous hydrogenated silicon (a-Si: H) having a large ON / OFF ratio and transparent to visible light can be used. The upper ITO film (display electrode) 23 and the TFT 34 are arranged in the sixth position.
As shown in the figure, it has a matrix shape, and further has drain electrode lines 31 extending in the vertical direction and gate electrode lines 32 extending in the horizontal direction. Details of the TFT 34 and the ITO film 23 are shown in FIG. Each island-shaped display electrode 23 is connected to the TFT 34 arranged at the lower left corner via the source electrode 33. In the gap between the island-shaped display electrodes 23, as shown in the drawing, the drain electrode lines 31 (1
5μm width), but also the gate electrode line 32 (15μ
m width) is running. Such TFT drive display electrode area 2
As shown in FIG. 8, reference numeral 5 indicates that a gate electrode wire 32 of Au-Cr is first formed on the glass substrate 24, and Si is formed on the gate electrode wire 32 by a mask method.
₃ N ₄ Insulating film 35, TFT 34 (a-Si: H) is formed in a vapor phase, and after etching Al drain electrode line 31 and source electrode 33 are formed by a vapor deposition method, and finally, an island-shaped display electrode (upper part) of the above size. IT
This is completed when the O film) 23 is formed by a mask method. An upper liquid crystal alignment film 22 is applied on this, and the liquid crystal layer 28 is arranged facing downward with the spacer 21 interposed therebetween.
The pattern of the island-shaped display electrode 23 is the island-shaped color phosphor region.
Since it is the same as the pattern of 18, the rectangular display face plate is completed by adjusting so that they match in the vertical direction (the optical shutter and the phosphor region overlap). This face plate (5
The display has 500 x 666 picture elements and an aperture ratio of about 80%. Liquid crystals having a dynamic scattering mode such as EBBA (p-ethoxybenzylidene-p'-n-butylaniline) and MBBA (p-methoxybenzylidene-p'-).
A 2: 3 mixture of n-butylaniline) can be used. Next, the linear excitation light sources 3 and 4 of the phosphor layer are the metallic light-reflecting outer lid in close contact with the condenser lenses 9 and 10 and the ultraviolet light lamp, socket, lead wire, power source, switch (second Partly shown in the figure) and the like. Inner glass plate of light-reflecting outer cover
15 is covered with an Al vapor deposition film 16 in order to increase the light reflectance. The UV lamp is a low-pressure mercury lamp (main emission wavelength 254n
m). The socket is used to apply a voltage to the UV lamp and to hold it in place to prevent UV light from leaking to the outside. Therefore, when the UV lamp is turned on, almost all emitted UV light (excitation light of the phosphor) is a condenser lens.
It is introduced into the excitation light scattering chamber 11 via 9, 10. Now, when this surface emitting display device is connected to an image display power supply device (not shown) and the switch is turned on, a signal voltage is applied to the liquid crystal optical shutter region of the rectangular display face plate. As the signal voltage, a gate signal S synchronized with the horizontal line of the television is applied to the gate electrode line 32 of the TFT, and line-sequential scanning is repeated. Further, an inverted video signal voltage Vin (a negative signal voltage obtained by inverting a strong video signal into a weak video signal) corresponding to each point is applied to the drain electrode line 31. This is because the dynamic scattering mode liquid crystal becomes opaque when a voltage is applied (it exhibits a shutter action). When the gate voltage is switched from 0V to 15V when the source / drain voltage is 2.8V, each TFT34 has a 6-digit change in drain current from 10 ^-12 A to 10 ^-6 A, and exhibits sufficient ON / OFF characteristics. Vivid TV images (frame frequency 60Hz) can be obtained. This equivalent circuit is shown in FIG. The luminous efficiency (electricity → light energy conversion efficiency) of this surface emitting display device reaches 12 to 20% when the entire surface is illuminated (no image display) (0.1 to 0.3% in the case of image display), 3%, 0.5-1.5% of the color liquid crystal TV (without image display) (about 0.01% with image display), which is a characteristic that greatly exceeds. In addition, the liquid crystal optical shutter layer 1 of this embodiment was shown to be as beautiful and vivid as a color cathode-ray, and to be as light, thin and easy to see as a color liquid crystal television. Therefore, the intensity of transmitted light is controlled for all polarization planes of transmitted light. In order to compare the high efficiency of electricity-to-light conversion energy of the surface emitting display device of the present invention, a surface emitting display device having a liquid crystal optical shutter of a specific polarization plane control basically composed of the same element configuration was prepared, and the efficiency was improved. Was measured. Example 2 A monochromatic character display panel (80 characters × 25 lines) having a display area of 224 × 98 mm ² was constructed by employing a time-division drive liquid crystal matrix optical shutter. That is, as shown in FIG. 10, the present apparatus is arranged on the upper glass substrate 19 of the vacuum region (excitation light scattering chamber) 11 in which a pair of straight tubular ultraviolet excitation light sources 3 and 4 are arranged along the long end face of the rectangular substrate. Split drive liquid crystal matrix optical shutter
1A is arranged, and a monochromatic phosphor layer 43 and an upper protective glass substrate 48 are further laminated on the 1A. Similar to the previous example, the excitation light scattering chamber 11 is a straight tube ultraviolet excitation light sources 3, 4 condensing lenses 9 and 10 in close contact, except the upper glass substrate 19, the glass plate 15 Al light reflection film 16 is vapor-deposited on the inner surface. It has a vacuum inside to prevent the absorption of ultraviolet rays. A light deflection plate 45 is in close contact with the lower surface of the upper glass substrate 19. On the other hand, a striped ITO film 50 and the same alignment film 51 are deposited on the upper surface of the upper glass substrate 19, and a twisted nematic liquid crystal 53 having a positive dielectric anisotropy of about 10 μm in thickness is formed via a spacer 52. It is enclosed. Upper liquid crystal electrode 54
Consists of a striped ITO film orthogonal to the striped ITO film 50. A liquid crystal alignment film 55 is applied to the ITO film 54. The striped ITO film 54 is formed on the back surface of the transparent glass plate 40, and between the front surface of the transparent glass plate 40 and the upper transparent glass plate 42, the lower light deflection plate 45 and the upper portion in the same plane of polarization are formed. The light deflection plate 41 is closely arranged. On the upper surface of the transparent glass plate 42, Y _{2 having a} thickness of about 20 μm is formed as the monochromatic phosphor layer 43.
SiO ₄ : Ce, Tb is applied. Although the upper protective glass layer 48 is disposed on the upper surface of the monochromatic phosphor layer 43, the phosphor layer
In order to keep 43 stable over time, it is desirable that the layer be sealed in a vacuum. The upper and lower ITO films 50 and 54 that sandwich the liquid crystal layer 53
Constitute an XY matrix orthogonal to each other, and a scanning signal voltage is applied to the X-axis direction stripe electrode 54 and a display signal voltage is applied to the Y-axis direction stripe electrode 50 in the form of alternating pulses, thereby providing an optical shutter function at each display point. It is something to have. That is, the substrate glass from the excitation light scattering chamber 11
The linearly polarized excitation light that has passed through the polarizing plate 45 via 19 enters the liquid crystal 53, but as the threshold voltage is not applied to the intersection of the XY stripe electrodes, the polarization plane rotates according to the twist of the liquid crystal molecules as it advances. Since it reaches the upper alignment film 55 and rotates 90 °, the light passing through the glass plate 40 is blocked by the upper polarizing plate 41 and cannot enter the phosphor layer 43. Therefore, in this case, no light emission is observed. However, when a voltage above the threshold value is applied to the intersection of the XY stripe electrodes, the liquid crystal is aligned in the direction perpendicular to the electrode surface, so the excitation light that has passed through the polarizing plate 45 is the liquid crystal 53 → the alignment film 55 → IT.
The light passes through the O film 54 → the glass plate 40 → the upper polarizing plate 41 and excites the corresponding part of the phosphor layer 43 arranged on the upper part thereof in a dot shape.
Therefore, in this case, the green body is displayed outside. In this embodiment, the number of X-axis stripe electrodes is 100 (0.5 mm width), that is, time division is performed at a duty ratio of 1/100, and a contrast ratio of 2 is obtained.
A good result of 0: 1 was obtained. When the character display panels of the same size are configured with only the liquid crystal optical shutter (non-emissive display) without using the phosphor layer as in this embodiment (duty ratio 1/100), the contrast ratio is 8: 1, It was clearly shown that the device of this example was excellent in terms of "easiness of viewing". On the other hand, in order to compare in terms of efficiency of conversion of electricity to light energy, white light was irradiated from the back surface of the non-emissive character display panel of the same size. That is, in FIG. 10, except for the monochromatic phosphor layer 43 and the upper protective glass layer 48, the ultraviolet excitation light source
A display device with white fluorescent lamps with excellent color rendering at the 3 and 4 positions (so-called backlit liquid crystal device)
Was configured. Comparing the electricity-to-light energy conversion efficiency by displaying the same display pattern as that of the display device of FIG. 10, it was found that the display device of FIG. 10 of the present invention was higher than the liquid crystal device with a backlight by about 40%. It is considered that this is mainly due to the difference in ultraviolet excitation efficiency between the two device phosphors (difference between high color rendering white phosphor excitation efficiency and green phosphor excitation efficiency). However, when comparing the monochromatic display device of this example with the color display device of the present invention of the previous example in terms of efficiency, it was found that the case of the previous example was about one digit higher. This is because, in the case of this embodiment, polarizing plates are provided in front of and behind the liquid crystal optical shutter so that only linearly polarized light can pass therethrough. That is, it is important to adopt a non-polarized light shutter for high efficiency driving. [Reference example] Display area of 5 x 7 segment matrix display 50 x 100 m
I made a number and character display device of m ² . In this case, the optical shutter is a peptyl viologen-based electrochromic display (ECD). The peptylviologen aqueous solution used as the ECD material is an organic substance, but it turns purple when a reduction reaction occurs by applying a voltage. The writing time is about 20 mm when 1 V is applied with a gap of about 1 mm from the counter electrode (anode), and about 25 msec when erasing the reverse voltage for erasing. Also, when coloring 254n
m Absorbance for ultraviolet rays is about 90%. As shown in Fig. 11, three ultraviolet lamps (straight tube) are installed in the longitudinal direction of the display device.
10 W) 60 are arranged to form a phosphor layer excitation light source, and a reflective metal film 16 is disposed on the glass substrate 15 by vapor deposition on the back surface thereof. A dot-patterned NESA film 61 is formed on the upper surface of the transparent glass substrate 19 above the excitation light source, and an opaque dot corresponding to a display point (diameter 2 mmφ, pitch 0.5 mm) is formed on the NESA film 61 as a through hole. The insulating film 62 is formed by screen printing. The through hole (depth of about 1 mm) is filled with the peptyl viologen aqueous solution 63. Next, a transparent IrO ₂ film 65 is vapor-deposited on the lower surface of the transparent glass plate 64 as a counter electrode and fixed so that the IrO ₂ film is in contact with the peptyl viologen aqueous solution. , And spacer 52
Sealed by. Y ₂ O ₃ : Eu was applied as a phosphor layer 70 on the upper surface of the transparent glass plate 64 to a thickness of about 30 μm, and the upper surface was sealed with a protective glass plate 48. The number and character display device is driven as follows. First, when a DC voltage of about 1.2 V is applied to the aqueous peptylviologen solution with the IrO ₂ film 65 as the plus and the NESA film 61 as the minus, the aqueous solution is colored purple due to the reduction reaction. If this coloring is left as it is, it can be "remembered" for about one month. Even if the phosphor layer excitation light source (ultraviolet lamp) 60 is turned on in this state, only a few percent of ultraviolet light passes through the ECD layer at most, so that the excited emission intensity of the Y ₂ O ₃ : Eu layer 70 is extremely weak. The optical shutter is in the "OFF" state. Next, only the NESA film dot electrode 61, which should be displayed as numbers / letters, is positive and the entire IrO ₂ film 65 is negative, and the voltage is about 1.1V.
When a direct current voltage of about 25 is applied, an oxidation reaction occurs only in the peptyl viologen aqueous solution region corresponding to the dot electrode 61, and the oxidation reaction occurs for about 25
The aqueous solution region becomes transparent in msec. As a result, the excitation light source
The 254 nm ultraviolet light emitted from 60 can pass through the transparent region to efficiently excite the corresponding region of the Y ₂ O ₃ : Eu phosphor layer 70, and the red light (λ = 611 nm) corresponding to the display dot can be emitted. It is released to the outside. That is, this state is the “ON” state of the ECD optical shutter. "ON" and "OFF" corresponding voltage application of these peptyl viologen aqueous solutions can be performed with a single square wave pulse of about 30 msec, so that the displayed contents can be changed one after another as needed. The display of numbers and characters on this display device has a high contrast (contrast ratio 30: 1) due to the red light emission pattern on the black-purple background, and the display effect is extremely large. In principle, the "ON" voltage of this ECD optical shutter is used. Halftone display is possible by controlling the value or pulse width, but it is more difficult to display gradation as clearly as the liquid crystal optical shutter of the previous embodiment. However, since the colored memory of the peptyl viologen aqueous solution lasts for one month as described above, the peptyl viologen aqueous solution can also be used as a fixed type numeric / character display. [Effects of the Invention] As described in detail above, according to the present invention, a combination of photoexcited fluorescence (photoluminescence) and an electronic optical shutter allows access to a display point and gradation adjustment to be performed on the optical shutter, thereby achieving high contrast. , A high-efficiency planar display device in which high visibility with a high color rendering property being shared by the photoexcitation phosphor has been disclosed. The features of the planar light-emitting device of the present invention can be summarized as follows: (1) a thin and lightweight high-definition display device, (2) a high contrast ratio and excellent visibility, and (3) a high luminous efficiency and therefore low power consumption. Yes, (4) it can be made portable because it can be driven at a low voltage, and (5) other light-emitting flat displays (light-emitting diodes,
Electroluminescent devices, plasma display devices, fluorescent display tube devices, etc.) can be manufactured at a lower cost (in the case of large-capacity display devices), (6) Also, because the photoexciting phosphor for performing visible display is sealed in a vacuum state, Highly efficient light emission can be stably maintained over a long period of time. The vacuum sealing can also contribute to high-efficiency light emission in terms of preventing ultraviolet ray attenuation due to air absorption in the scattering chamber (that is, when ozone is generated, this ozone absorbs the ultraviolet ray, and as a result, the ultraviolet ray is attenuated. However, when vacuum is applied, ozone is not generated, so there is no absorption of ultraviolet rays and there is no attenuation). If the straight tube UV lamp is exhausted, it can be easily replaced without breaking the vacuum. Therefore, it can be seen that the display device for an information processing terminal has a high-performance display comparable to that of a cathode ray tube and a light weight comparable to a liquid crystal display device. In this embodiment, the case where the liquid crystal and the ECD are used as the optical shutter has been described. However, it is obvious that the electrophoretic effect and the electro-optical effect of the dielectric can be used in principle other than this.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external view of a surface emitting device according to the present invention, FIG. 2 is an external view of a light irradiation section, and FIG. 3 is an operation explanatory view of an individual optical shutter,
FIG. 4 is a device structure diagram in one embodiment of the present invention, FIG. 5 is an array diagram of phosphor layers, and FIGS. 6, 7, and 8 are liquid crystal driving parts in the device shown in FIG. 9 is an equivalent circuit diagram, FIG. 10 is a device structure main part view in another embodiment of the present invention, and FIG. 11 is a device structure main part view in a reference example of the present invention. is there. In the figure, 15 is the lower glass plate of the excitation light scattering chamber, 16 is a metal reflective film, 9 and 10 are lenses for collecting the excitation light, 19 is the upper glass plate of the excitation light scattering chamber, and 18 is an island-shaped phosphor region. , 20 is lower ITO film (lower transparent electrode), 26 is lower liquid crystal alignment film, 28 is liquid crystal, 22 is upper liquid crystal alignment film, 21 is spacer, 23 is upper ITO film (upper transparent electrode), 25 is TFT drive display Electrode areas, 3 and 4 are straight tubular ultraviolet excitation light sources, 43 is a monochromatic phosphor layer, 24 and 48 are upper protective glass plates of the display device, 45 is a lower light deflection plate, 41 is an upper light deflection light plate, and 42 is transparent glass. A plate, 62 an opaque insulating film, 63 an aqueous solution of peptyl viologen, 65 an IrO ₂ counter electrode, and 17 a non-emissive black matrix region.

Claims (1)

(57) [Claims] Excitation light scattering chamber, photoexcitation phosphor layer, optical shutter layer is loaded in this order, visible light emitted by exciting the photoexcitation phosphor layer by ultraviolet rays of a constant intensity irradiated from the excitation light scattering chamber In the planar light-emitting device that controls the intensity by a predetermined information signal of the optical shutter layer and displays it as an optical image outside the optical shutter layer, the excitation light scattering chamber has a rectangular parallelepiped hollow region, and the hollow region Of the pair of parallel parallel side surfaces each including a condenser lens for introducing ultraviolet light, and the inside of the hollow area other than the parallel side surfaces of the photoexciting phosphor layer mounting surface and the condenser lens arrangement. The wall surface is composed of a light scattering surface, and the inside of the hollow region is vacuum-sealed to include the phosphor region of the phosphor layer for photoexcitation, and the outside of the excitation light scattering chamber of the condensing lens, respectively. A planar light emitting device in which a straight tube ultraviolet lamp is arranged. 2. The excitation light scattering chamber, the optical shutter layer, and the photoexcitation phosphor layer are stacked in this order, and the intensity of the ultraviolet light having a constant intensity emitted from the excitation light scattering chamber is controlled by a predetermined information signal of the optical shutter layer. After that, in the planar light emitting device that displays as a light image outside the visible light radiated by irradiating the phosphor layer for photoexcitation, the excitation light scattering chamber has a rectangular parallelepiped hollow region, and the hollow region faces each other. The pair of parallel two side surfaces each include a condenser lens for introducing ultraviolet light, and the inner wall surfaces of the hollow region other than the parallel two side surfaces of the optical shutter layer mounting surface and the condenser lens arrangement are light scattering surfaces. And the inside of the hollow region and the phosphor region of the photoexcitation phosphor layer are vacuum-sealed, and a straight tube ultraviolet lamp is arranged outside the excitation light scattering chamber of the condenser lens. It A planar light emitting device characterized in that