JP2000348648A - Display light emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep internal vacuum degree high and allow long stable operation by providing a proximity of an electron source corresponding to a phosphor dot with another electron source with a different electron emission characteristic. SOLUTION: A stripe-like cathode electrode 15 is formed on a back substrate 1, and resistance layers 16 are provided on it for suppressing current change. A gate electrode 17 is formed orthogonally to the cathode electrode 15 across an insulating layer 18. A plurality of round openings 19 are provided in a crossing part between the cathode electrode 15 and the gate electrode 17. An out-gas cathode 13 and a display cathode 14, which are electron emitting parts connected to the resistance layer 16, are placed in the opening 19. Electrons emitted from an out-gas cathode tip 13 having low electron emission starting voltage lower than the display cathode 14 are accelerated with voltage supplied to an aluminum film 5, collide with a phosphor 3 through the aluminum film 5, and emits gas in the phosphor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display light emitting device using a field emission cathode as an electron source.

[0002]

2. Description of the Related Art In recent years, CRTs (C
A good space factor in place of athrode ray tube) · LCD (Liquid Crystal)
l Display) or PDP (Plasma Dis
A flat panel display such as a play panel is becoming mainstream. In addition, an FED (Field) which is a flat panel display which is excellent in brightness and color reproducibility of a display screen by a self-luminous system excited by an electron beam as in a CRT.
The development of dEmitter Display (hereinafter referred to as ED) is also being actively carried out.

This FED uses a field emission device (cold cathode device) as an electron source. Whereas conventional CRTs emit electrons by heating, FRTs
The ED locally applies a high electric field to emit electrons by field emission. In particular, while a display element using a hot filament cathode cannot display a high-definition image, by using the field emission cathode, a high-definition degree sufficient for use in an information terminal can be obtained. It has become possible to realize a display with.

A display light emitting device using such a field emission type cathode is disclosed in, for example, Japanese Patent Application Laid-Open No. 3-208241.
The one described in Japanese Patent Application Laid-Open Publication No. H10-260, 1993 is known. FIG. 14 is a diagram showing a configuration of a conventional display light emitting element described in the publication, and FIG. 14 is a cross-sectional view of the display device as viewed from a side.
In the figure, 101 is a rear panel (rear substrate), 102
Is a front panel (front substrate), 103 is an emitter chip (cold cathode chip), 104 is a gate electrode (data electrode), 105 is an insulating layer, 106 is a phosphor constituting a display pixel, 107 is a spacer (side plate), 108 Is the external electrode,
109 is an external terminal for the anode electrode, 110 is an insulating layer, 111
Is a beam focusing electrode, 112 is an anode electrode, and 113 is an insulating substrate.

A display light emitting device using this field emission device is composed of a front panel 102 having a transparent substrate on which an anode electrode 112 and a phosphor 106 are formed, and a rear panel 101 having a cold cathode element formed on a surface, and a spacer 107. The inside of the vacuum container is evacuated by an exhaust pipe (not shown) to be in a vacuum state.

FIG. 15 shows the configuration of a cold cathode device.
As shown, a cathode electrode 114 and a gate electrode 104 are arranged in a matrix on a back panel 101 with an insulating layer 105 interposed therebetween, and a plurality of openings 115 are provided at intersections thereof, and electron emission is provided therein. A conical emitter tip 103 as a portion is formed.

Next, the operation will be described with reference to the drawings. By applying a potential difference of several tens of volts between the cathode electrode 114 and the gate electrode 104 of an electron source having a large number of emitter chips 103, a high electric field is applied to the tip of the emitter chip 103 and electrons are extracted. The emitted electrons are attracted to the anode electrode 112 on the side of the front panel 102 to which the high voltage is applied via the anode electrode external terminal 109, and collide with the phosphor 106, whereby the phosphor 10
6 is excited to emit light. At this time, the beam focusing electrode 1
By applying an appropriate voltage to the electron beam 11, the electron beam emitted from the emitter tip 103 is focused.

The cathode electrode 114 and the gate electrode 104
Are external electrodes 10 so that pixels (phosphors) emit light sequentially.
8 are driven in a line-sequential manner. As a result, the phosphor 106 facing each pixel sequentially emits light, and the front panel 102
And a display image is formed.

[0009]

It is generally known that the performance of a field emission cathode depends on the degree of vacuum inside. In an ultra-high vacuum device of 10 ^-8 Pa,
It operates stably for 10,000 hours or more, but when the degree of vacuum is 10 ^-4 Pa or less, noise is generated in the emission current waveform, and the current is reduced by half in several hundred hours. In particular, this phenomenon occurs at the initial stage of the aging process until the operation becomes stable after the display light emitting element is completed, and the degree of vacuum is reduced by gas generated from inside the panel constituent materials such as phosphor screen and electrodes by electron impact. In addition, the gas damages the cathode chip greatly, and significantly lowers the current emission characteristics.
This is a fatal drawback as a field emission display light emitting element alone or a display device using the same, and causes inconveniences such as flickering of images, variation in luminance, and shortening of life.

Therefore, it is necessary to maintain the inside of the vacuum container (light-emitting display tube) at a high degree of vacuum for a long time even after the completion of the device.
For this purpose, it is necessary to provide a large number of getters for absorbing gas inside the container or to extremely reduce the amount of gas generated from inside the container.

However, in a display light emitting device using a field emission cathode, the height inside the vacuum vessel (gap between the front panel and the back panel) is a thin structure of about several millimeters. There was a problem that it could not be installed.

In order to sufficiently release the gas released from the inside of the vacuum vessel when the device is manufactured, the exhaust process is performed, for example, by 35 seconds.
Even if baking is performed at a high temperature of about 0 ° C., there is a problem that it is impossible to sufficiently release gas from the inside of the phosphor or the metal thin film.

The present invention has been made in order to solve the above-mentioned problems. Even when only a small number of getters can be installed inside, the amount of gas released inside after the device is formed can be reduced. An object of the present invention is to provide a display light-emitting element that can maintain a high degree of internal vacuum at a high level and can operate stably for a long time.

It is another object of the present invention to provide a display light-emitting device which can efficiently perform an evacuation process for increasing the degree of vacuum inside the device in a short time.

[0015]

According to the present invention, there is provided a display light emitting device comprising: a front panel on which a phosphor is formed; and a cold cathode which faces the front panel and emits electrons for exciting and emitting the phosphor. A display light emitting device including a back panel on which a first electron source made of a field emission device of a type is formed, wherein the back panel includes the first electron source corresponding to a phosphor dot, The display device includes a second electron source having different electron emission characteristics for emitting gas from the surface and the inside of the constituent member of the display light emitting element.

Further, the opening of the electron emitting portion of the second electron source is smaller than the opening of the first electron source.

Further, the height of the electron emission portion of the second electron source is closer to the height of the gate electrode than the height of the first electron source.

The radius of curvature of the tip of the electron emission portion of the second electron source is smaller than the radius of curvature of the electron emission portion of the first electron source.

Further, the material of the electron emitting portion of the second electron source is a material having a smaller work function than the material of the cathode tip of the first electron source.

Furthermore, no resistance layer is provided below the electron emission portion of the second electron source.

Further, the resistance value of the resistance layer below the electron emission portion of the second electron source is smaller than the resistance value of the first electron source.

Further, the first electron source and the second electron source are formed in the same region in the electron emission portion corresponding to the phosphor dot.

Further, a second electron source formed on the same gate electrode is arranged at a distance from the first electron source arranged in the electron emitting portion corresponding to the phosphor.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a field emission display light emitting device according to the present invention will be described below in detail with reference to FIGS.

Embodiment 1 FIG. 1 is a structural diagram of an electron source according to an embodiment of the present invention, and FIG.
FIG. 2 is a perspective view illustrating a configuration of a display light emitting element.

In the drawing, 1 is a rear substrate, 2 is a front substrate, 3 is a phosphor formed on the inner surface of the front substrate 2 and constitutes each luminescent pixel, 4 is a black insulator formed in a gap between the phosphors 3, 5 is an aluminum film as an anode electrode, 6 is a shield electrode for shielding an electric field, 7 is a spacer, and the back substrate 1, the front substrate 2, and the spacer 7 are joined and sealed with low melting point glass to form a vacuum vessel. Is configured.
Reference numeral 8 denotes an exhaust pipe for evacuating the inside of the vacuum vessel to a high vacuum state at the time of element fabrication, 9 denotes a getter installed in the exhaust pipe 8 and on the front substrate 2 to adsorb gas inside the vacuum, and 10 denotes An external extraction electrode for extracting various electrodes inside the device to the outside, 11 is an anode extraction electrode for supplying an accelerating voltage to the anode, and 12 is a large number of field emission type (cold cathode type).
It is an electron source composed of a cathode, and is composed of a field emission cathode 13 for gas emission (for outgassing) and a field emission cathode 14 for display. The gas discharge cathode 13 is arranged near the display cathode 14. Reference numeral 15 denotes a cathode electrode for inputting an image signal, 16 denotes a resistance layer provided for suppressing current fluctuation, 17 denotes a gate electrode for inputting an operation signal, 18 denotes an insulating layer, and 19 denotes an opening.

As shown in FIG. 2, a front panel 1 having light emitting means is opposed to a rear panel 1 on which a field emission element is formed, and is joined and sealed with low melting glass with a spacer 7 surrounding the periphery interposed therebetween. Constitute a vacuum container. An exhaust pipe 8 for exhausting the inside of the vacuum vessel to a high vacuum state is joined to the back panel 1, and a getter 9 is provided above the exhaust pipe 8 and on the front substrate 2. The inside of the vacuum container is maintained at a degree of vacuum of about 10 ⁻⁵ Pa by the getter 9.

The external extraction electrode 10 for supplying a voltage for driving the cold cathode is pulled out from the rear side by a pin. In the present embodiment, the field emission type display light emitting elements are arranged in a matrix to form an array type display, and the external extraction electrode 10 is taken out from the back side. When used alone as a display panel, it may be possible to extend the electrodes on the back panel 1 and take it out from the end portion, which can be easily connected to an external drive board.

Further, an anode extraction electrode 11 for supplying an accelerating voltage to the phosphor 3 of the front panel 2 has one end joined to the aluminum film 5 as an anode electrode, the periphery thereof is coated with an insulating material such as glass, and exhaust is performed. It is taken out through the tube 8.

Next, the configuration of the back panel 1 will be described. As shown in FIG. 2, there is an electron source 12 corresponding to the phosphor dots 3 on the front substrate 2, in which a number of field emission devices are formed. Here, the field emission element used is preferably, for example, a Spindt-type cold cathode. Hereinafter, the configuration of an electron source using a Spindt-type cold cathode will be described.

As shown in FIG. 1, a cathode electrode 15 in the form of a stripe is formed on the rear substrate 1, and a resistive layer 16 provided on the cathode electrode 15 for suppressing current fluctuation. The resistance layer 16 can be formed on the entire surface of the rear substrate 1, or can be formed for each dot, for each line, or for each chip. In the first embodiment, an example is described in which a resistance layer 16 is formed for each cathode chip. A gate electrode 17 is formed orthogonal to the cathode electrode 15 with the insulating layer 18 interposed therebetween. At the intersection of the cathode electrode 15 and the gate electrode 17, a plurality of circular openings 19 are formed.
Is provided. In the opening 19, there are an outgassing cathode 13 and a display cathode 14 which are connected to the above-mentioned resistance layer 16 and are electron emitting portions.

The electron emission characteristics of this Spindt-type field emission cathode vary depending on its shape, structure, material and the like. As shown in FIG. 3, the electric field intensity changes depending on the radius R of the opening, the radius of curvature r of the tip of the cathode tip, and the height h of the tip, and the electron emission characteristics also change depending on the work function φ of the tip material. Further, the characteristics can be changed by changing the cathode potential by the specific resistivity ρ of the resistance layer 16 connected to the cathode chip.

As shown in FIG. 3, the radius of curvature r at the tip of the cathode tip is small, the opening diameter R is small, the tip height is the same as the gate height h, and the work function φ of the cathode tip material is as shown in FIG. Is smaller, and the specific resistivity of the resistance layer 16 is smaller or not.
th is small, and the curve of the electron emission characteristics moves to the left.
In the present invention, the electron emission start voltage Vth is small (Vth
1) Using the cathode as the cathode 13 for outgassing,
A cathode having a large Vth (Vth2) is used as the display cathode 14. In the first embodiment, as shown in FIG. 1, an example is shown in which the opening diameter R is small in the outgas cathode and large in the display cathode.

The anode phosphor screen having the light emitting means is positioned on the front panel 2 made of a transparent material so that the red R, green G, and blue B phosphor patterns 3 correspond one-to-one with the display light emitting electron sources. And a black insulating layer 4 for obtaining a good contrast is formed in a gap between the respective phosphor 3 regions. Further, an aluminum film 5, which is an electrode for applying a voltage, is formed on the entire anode phosphor screen or at least on the surface of the phosphor 3 region. In the present embodiment, one phosphor 3 for four dots of red, green, green and blue (RGGB) is used.
Although a cross-shaped array that forms pixels is taken as an example, a trio array that forms one pixel by arranging red, green, and blue (RGB) horizontally in stripes may be used. Also, an aluminum film is selected as the anode electrode in order to emit light by applying a high voltage.
A transparent electrode such as (Indium Tin Oxide) is provided on the front panel 2, and a low voltage phosphor (for example, driven at an anode voltage of 1 to 2 kV or less) is disposed on the front electrode 2. Good.

Next, the electron source 1 according to the above-described embodiment will be described.
2 and a method for manufacturing a display light emitting element will be described.

First, for example, Ta, Cr,
A metal film such as Nb is formed to a thickness of 0.5 μm, a mask is formed by photolithography and photoresist, and the pattern of the cathode electrode 15 is formed by reactive ion etching (hereinafter referred to as RIE) or wet etching with an etching solution. Form.

Then, a silicon film as the resistance layer 16 is formed by the same method as described above. Further, an insulating layer 18 made of SiO _{2 is} stacked by about 1.0 to 1.5 μm by a CVD method. Next, a metal film is formed thereon to form a gate electrode pattern in the same manner as described above. Then, a mask is formed by photolithography and photoresist, and a plurality of minute openings are formed in the gate electrode 17 and the insulating layer 18 by RIE. At this time, when the mask is formed by the photoengraving method, the diameter of the opening 19 is set to 1 for the outgas cathode 13.
By making the display cathode as small as about μm and as large as about 3 μm, cathodes having different electron emission characteristics can be obtained. Then, chromium is deposited obliquely to form a sacrificial layer. Thereafter, a conical cathode tip is formed by depositing a material for the cathode tip, for example, molybdenum from directly above. Finally, chromium is removed by wet etching to form a Spindt-type field emission cathode.

Next, the fluorescent screen, which is a light emitting means, will be described. The anode phosphor screen is formed by printing and baking a black insulating material such as carbon on the front panel 2 made of a transparent material to form the black insulating layer 4. Then, the red R, green G, and blue B phosphors 3 are applied by a printing method, and are formed by firing.
The filming liquid is dropped while rotating the front panel 2 on which the phosphors 3 are formed by a spinner to form a filming film. After leaving and drying, aluminum is deposited and baked to form an aluminum film 5 as an anode electrode.

Then, the rear panel 1 on which the cold cathode is formed, which is a component of the display light emitting element, the front panel 2 on which the phosphor is applied, the shield electrode 6, the spacer 7, and the exhaust pipe 8
Are sealed in a firing furnace with a low-melting glass that sinters at about 450 to 500 ° C. to produce a vacuum vessel (light-emitting display tube).

The vacuum vessel sealed and joined to the exhaust device is set, the temperature in the furnace is raised to about 350 ° C., and a predetermined high vacuum is applied from the exhaust pipe 8 to the inside of the vacuum vessel by using a turbo pump or a diffusion pump. Exhaust so as to be in a state. After the evacuation is completed, heat is applied to the exhaust pipe 8 to close the tip, thereby completing the display light emitting element. After completion, exhaust pipe 8
A high-frequency magnetic field is applied from the outside to the getter 9 installed in the inside and the front substrate 2, induction heating is performed to about 800 to 900 ° C., and barium is diffused into the getter container on the rear substrate side of the exhaust pipe 8 and the front substrate to activate. And maintain and improve the degree of internal vacuum. As for the getter 9, a non-evaporable getter which can be activated at the exhaust temperature without induction heating may be inserted into the exhaust pipe 8 before the exhaust.

Next, a method of driving the electron source according to the present embodiment will be described with reference to FIGS.

The anode voltage Va is supplied to the aluminum film 5 of the front substrate 2 from the anode power supply 20 through the anode extraction electrode 11. First, when Vo (FIG. 4) is supplied from the driving power supply 21 connected to all the gate electrodes 17 and the cathode electrodes 15 of the display light emitting element, electrons are emitted from the outgassing cathode chip 13 having a small chip opening diameter and a low electron emission start voltage Vth1. (e ^-) are emitted (Figure 5 (a)). The emitted electrons are accelerated by the voltage supplied to the aluminum film 5, penetrate the aluminum film 5, collide with the phosphor 3, and emit gas inside the phosphor. At this time, since the voltage of the display cathode chip 14 has not reached the electron emission start voltage Vth2, electrons are not emitted. Therefore, the + ions generated by the collision of the electrons with the residual gas return to the electron trajectory, and the ion bombardment that degrades by colliding with the cathode tip does not occur. Such deterioration occurs only in the cathode tip 13 for gas release. After sufficient gas is released from the phosphor 3 by the outgassing cathode 13, the voltage is increased to Vth2 or more to drive the display light emitting element (FIG. 5B).

The operating condition of the outgassing cathode 13 is the same as or higher than that for performing the original display operation, and the cathode-gate driving voltage Vcg is set to a value of, for example, about 12 KV. The voltage is raised to a voltage value slightly lower than the electron emission start voltage Vth2 of the display cathode 14, for example, 50 V, and then maintained (keeped) at 50 V, and gas is gradually released in about 30 to 60 minutes.

It is desirable that such an outgassing operation be performed at the time of evacuation during the light emitting element manufacturing process described above. This is because the degree of vacuum in the light emitting element increases because the gas released from the phosphor screen exits the light emitting element without remaining inside the light emitting element. However, when it is difficult to supply the driving voltage, the above-described outgassing operation may be performed after the device is completed by vacuum sealing, and the same effect can be obtained. In this case, since the amount of gas adsorbed by the getter is limited, more getters are required to maintain the internal vacuum for a long time than in the case of exhausting.

Embodiment 2 In Embodiment 2, the height of the outgassing cathode chip 13 of the electron emitting portion is higher than that of the display cathode chip 14,
It is formed at a height close to the gate electrode. As shown in FIG. 6, when a driving voltage is applied between the gate and the cathode, electrons are emitted at a low voltage because a stronger electric field is concentrated on the outgassing cathode closer to the gate electrode. The electrons reach the phosphor and release gas from the phosphor.

The method of manufacturing the back substrate of the present embodiment is the same as that of the first embodiment, and the details are omitted.

Embodiment 3 In Embodiment 3, as shown in FIG. 7, the radius of curvature of the tip of the outgassing cathode tip 13 of the electron emission portion is formed smaller than that of the display cathode tip 14. The radius of curvature of the cathode tip depends on the cathode material. For example, a material of Ni is used for the outgas cathode 13 so that the tip is sharp, and a separate M is used for the display cathode.
By using the material o, the radii of curvature at the tips of both cathodes can be changed.

Further, the method of manufacturing the back substrate according to the present embodiment uses the cathode electrode 15 and the resistance layer 1 shown in the first embodiment.
6. After laminating the insulating layer 18 and the gate electrode 17, the process of forming the cathode chip is repeated twice separately for the outgassing cathode and the display cathode. The details are the same as in the first embodiment, and a description thereof will be omitted.

Embodiment 4 In Embodiment 4, as shown in FIG. 8, the electron emission characteristics are changed by changing the material of the cathode. The material of the cathode has a constant called the work function φ of the material itself, and the smaller this value is, the more the electron emission is likely to occur. For example, LaB ₆ = 2.2, TiN = 2.9,
-W = 4.5, Au = 4.3, Mo = 4.3. Here, by using a material having a small work function for the outgassing cathode 13 and using a material having a larger work function for the display cathode 14, it is possible to form cathodes having different electron emission characteristics.

The method of manufacturing the back substrate according to the present embodiment is the same as that of the third embodiment, and thus the details are omitted.

Fifth Embodiment In the fifth embodiment, as shown in FIG. 9, a resistance layer is not formed on the outgassing cathode 13, and the display cathode 14 has a resistance between the cathode chip 14 and the cathode electrode 15. The layer 16 is formed. In a cathode having no resistive layer, the amount of emitted electrons is not limited by the amount of current flowing through the resistive layer. On the other hand, since the potential of the cathode increases in proportion to the current flowing by forming the resistance layer 16 on the cathode chip 14 and the cathode electrode 15, the actual voltage between the gate and the cathode decreases, and electron emission is suppressed. . By this operation, the cathode 1 for outgassing
In No. 3, since sufficient electron emission occurs at a low voltage and sufficient electron emission does not occur unless a high voltage is applied to the display cathode 14, different electron emission characteristics can be provided.

Further, the method of manufacturing the back substrate according to the present embodiment is such that when forming the resistance layer in the first embodiment, the pattern of the resistance layer is formed by photolithography for each chip or each region. It can be manufactured well without increasing the number of steps to be performed.

Embodiment 6 In Embodiment 6, as shown in FIG. 10, a resistance layer 16a having a small resistance value is formed on the outgas cathode 13, and a resistance layer 16b having a large resistance value is formed on the display cathode 14. Things. This is the same means as in the fifth embodiment. However, the conventional resistance layer is formed to stabilize the electron emission characteristics, and in order to aim for this effect and the effect of the present invention, this embodiment is used. The form is more desirable. If the resistance layer is omitted in the above-described example, the electron emission is different between the adjacent electron emission portions, and the intended purpose of outgassing from the phosphor cannot be sufficiently achieved by all the phosphors. In addition, if an overcurrent flows to some field emission devices, the current cannot be suppressed, so that the cathode emission portion is destroyed and a short circuit occurs between the cathode and the gate, leading to deterioration of the entire electron source.

The method of manufacturing the rear substrate according to the present embodiment includes two steps of forming silicon with different resistivity ρ between the outgas cathode 13 and the display cathode 14 at the time of forming the resistance layer according to the first embodiment. It may be formed. Further, the resistance value may be changed by performing ion implantation on the formed resistance layer.

Embodiment 7 Next, the arrangement of the outgassing cathode will be described here. The cathode 13 for out and the cathode 14 for display are arranged in the electron source 12 corresponding to one dot of the phosphor, but in order to sufficiently release gas from the phosphor 3, it is necessary to consider the arrangement method. is there.

As shown in FIGS. 11 and 12, in the seventh embodiment, an outgas cathode 13 and a display cathode 14 are arranged in the same electron source region corresponding to the phosphor dots. For example, as shown in FIG. 11, the outgassing cathodes 13 are arranged in a striped manner. Alternatively, as shown in FIG. 12, the outgassing cathode 14 is arranged for each area.

In contrast to the display cathode 14, the number of the outgassing cathodes 13 may be small in order to discharge the phosphor. The field emission cathode tip has a large electron divergence angle of 30 °, so it is possible to outgas the entire phosphor screen with a small number of cathodes.However, because the number of emitted electrons is small, effective phosphor outgassing is required. It is desirable to set the anode voltage higher than during driving. By increasing the anode voltage, a small amount of emitted electrons are accelerated to give sufficient energy to the phosphor, so that sufficient outgassing from the phosphor can be achieved.

Embodiment 8 In Embodiment 8, as shown in FIG. 13, the outgassing cathode 13 is replaced with the display cathode 1 corresponding to the phosphor dot 3.
4 is arranged in another area adjacent to the area 4. However, both cathodes are on the same gate electrode. In this case, the electrons emitted when driven are directed to the anode surface (aluminum film 5) immediately above, and cannot reach the phosphor. Therefore, the structure of the phosphor screen is changed so that the aluminum film 3 is formed only on the phosphor. In this way, the emitted electrons travel toward the phosphor dots 3, so that the effect of phosphor outgas can be expected.

According to this structure, even if gas or ions generated by collision of electrons with the fluorescent material affect the outgassing cathode 13 as ion bombardment, the gas or ions are separated and arranged in another region. It is considered that the influence on a certain display cathode 14 is small. Further, since it is formed in an area other than the area corresponding to the phosphor dots 3, there is an advantage that a sufficient number of cathode chips can be arranged on the display cathode 14.

[0060]

Since the present invention is configured as described above, it has the following effects.

On the back substrate, near the cold cathode type first electron source arranged corresponding to the phosphor dots, apart from the field emission element related to image display, the constituent members of the display light emitting element A second electron source having different electron emission characteristics for emitting gas from the surface and the inside of the device, driving the second electron source at the time of evacuation or at the completion of evacuation of the manufacture of the display light emitting element, and the electrons emitted therefrom. As a result, gas is released from the components of the display element, so that the amount of gas released from within the element after the display element is completed is extremely small, and the degree of vacuum can be sufficiently increased. As a result, the initial activation of the first electron source composed of the field emission type cathode can be performed in a high vacuum state, so that the initial deterioration of the field emission type cathode can be suppressed and good current characteristics can be obtained. .

Further, the shape of the display light emitting element becomes thin,
Even if a sufficient getter cannot be provided, a sufficient amount of gas is emitted by the second electron source, so that a high vacuum can be maintained with a small amount of getter. As a result, the life of the display light emitting element can be extended, and the reliability of the element can be increased.

Further, since the shape of the opening of the field emission type cathode of the second electron source is changed, it is possible to easily manufacture the field emission type cathode by the same process as the conventional one.

Also, by changing the height of the field emission type cathode tip of the second electron source, it is possible to manufacture cathodes having many different electron emission characteristics.

By changing the material of the second electron source, the radius of curvature at the tip of the cathode tip can be controlled.
The cathode is easy to manufacture.

Further, since the cathode tip of the second electron source is made of materials having different work functions, the electron emission characteristics of the field emission cathode depend on the material, so that stable cathodes having different characteristics can be obtained.

Further, since the electron emission characteristics of the first electron source and the second electron source are changed depending on the presence or absence of the resistance layer, the cathode chip can be formed in one process, and can be easily formed only by changing the mask pattern of the resistance layer. It is possible to manufacture.

Further, since the first electron source and the second electron source are controlled by the resistance value of the resistance layer, it is possible to realize nearly ideal electron emission characteristics depending on the design value of the resistance value.

Further, since the second electron source is disposed immediately below the corresponding phosphor dot, gas can be efficiently released from the phosphor and a sufficiently high vacuum can be attained.

Further, since the second electron source is separated from the first electron source, it is possible to emit electrons without affecting the first electron source.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a part of a configuration of a display light emitting device according to a first embodiment of the present invention.

FIG. 2 is a perspective view illustrating a configuration of a display light emitting device according to the first embodiment of the present invention.

FIG. 3 is a diagram for explaining parameters related to the electron emission characteristics of the field emission device of the present invention.

FIG. 4 is a view showing electron emission characteristics of a first electron source and a second electron source which are field emission devices of the present invention.

FIG. 5 is a diagram for explaining a method of driving the first electron source and the second electron source of the display light emitting device of the present invention.

FIG. 6 is a perspective view showing a part of a configuration of a display light emitting device according to a second embodiment of the present invention.

FIG. 7 is a perspective view showing a part of a configuration of a display light emitting device according to a third embodiment of the present invention.

FIG. 8 is a perspective view showing a part of a configuration of a display light emitting device according to a fourth embodiment of the present invention.

FIG. 9 is a perspective view showing a part of a configuration of a display light emitting element according to a fifth embodiment of the present invention.

FIG. 10 is a perspective view showing a part of a configuration of a display light emitting element according to a sixth embodiment of the present invention.

FIG. 11 is a diagram showing an example in which the second electron sources of the display light emitting device of the present invention are arranged in a stripe shape.

FIG. 12 is a view showing an example in which the second electron sources of the display light emitting element of the present invention are dispersed.

FIG. 13 is a diagram showing an example in which the second electron source of the display light emitting device of the present invention is arranged separately from the first electron source.

FIG. 14 is a cross-sectional view illustrating a configuration of a conventional display light emitting element.

FIG. 15 is a perspective view showing a configuration of a Spindt-type field emission device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 back substrate, 2 front substrate, 3 phosphor, 4 black insulating layer, 5 aluminum film, 6 shield electrode, 7 spacer, 8 exhaust pipe, 9 getter, 10 external extraction electrode, 11 anode extraction electrode, 12 electron source, 13 Outgas cathode, 14 Display cathode, 15 Cathode electrode, 16 Resistive layer, 17 Gate electrode, 18 Insulating layer, 19 Opening.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Noritsuna Hashimoto, Inventor 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Corporation (72) Inventor Shuji Iwata 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Corporation (72) Inventor Akihiro Watanabe 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Kosaburo Shibayama 2-3-2 Marunouchi, Chiyoda-ku, Tokyo 3 Rishi Electric Co., Ltd. F term (reference) 5C031 DD09 DD17 5C032 JJ08 JJ17 5C036 EE19 EF01 EF06 EF09 EG12 EH04 EH23

Claims (9)

[Claims] 1. A front electron source comprising a front substrate on which a phosphor is formed and a cold cathode type field emission element which faces the front substrate and emits electrons for exciting and emitting the phosphor. A display light emitting device including a formed rear substrate,
The back substrate has a field for emitting gas from the surface and inside of the display light emitting element, separately from the field emission element related to image display in the vicinity of the first electron source corresponding to the phosphor dot. A display light emitting device comprising a second electron source having different electron emission characteristics. 2. The display light emitting device according to claim 1, wherein the size of the opening of the electron emitting portion of the second electron source is smaller than the size of the opening of the electron emitting portion of the first electron source. 3. The display light emitting device according to claim 1, wherein the height of the electron emitting portion of the second electron source is closer to the height of the gate electrode than the height of the electron emitting portion of the first electron source. 4. The display light emitting device according to claim 1, wherein a radius of curvature of a tip of an electron emitting portion of the second electron source is smaller than a radius of curvature of an electron emitting portion of the first electron source. 5. The display light emitting device according to claim 1, wherein a material of an electron emitting portion of the second electron source has a work function smaller than a material of an electron emitting portion of the first electron source. 6. The display light emitting device according to claim 1, wherein a resistance layer is not provided below an electron emission portion of the second electron source. 7. The resistance value of a resistive layer below an electron emission portion of the second electron source is smaller than that of the first electron source.
The display light-emitting device according to any one of the preceding claims. 8. The display light emitting device according to claim 1, wherein the second electron source is arranged and formed in a region of the electron source corresponding to the phosphor dot, mixedly with the first electron source. 9. The display light emitting device according to claim 1, wherein the region of the second electron source is arranged and formed on the same gate electrode that is separated from the region corresponding to the first phosphor dot.