JPH0927287A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device having high reliability and capable of thinning, in which thermal deformation of a display panel does not occur. SOLUTION: A display panel 10 serving as a closed container is formed of a front plate 2, a back plate 3, and a frame 4. Inside the panel 10, an image forming part 20 is provided on the front plate 2, and an electron emitting element part using an electron emitting element is provided on the back plate 3 in such a way as to oppose to the image forming part 20. Further, the image forming device has an area where the back plate 3 is projected beyond the outer periphery of the frame 4, and an electric component 7 that heats the area via a heat conducting member is installed in contact with the area. The heating electric component 7 is mounted on an electric circuit substrate 6 and outside the electron emitting element part, other electric components 8 are mounted inside the electron emitting element part, and an electrical connection between the electric circuit substrate 6 and the display panel 10 is made using wiring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitting devices, a thermionic electron source and a cold cathode electron source, are known. The cold cathode electron source includes a field emission type (hereinafter abbreviated as FE type), a metal / insulating layer / metal type (hereinafter abbreviated as MIM type), and a surface conduction type electron emission element. As an example of the FE type, W. P. Dyke &
W. W. Dolan, "Field Emissio"
n ", Advance in Electron Ph
ysics, 8 89 (1956) or C.I. A. S
pindt, "Physical Property"
s of thin-film field emis
sion cathodes with mollybd
enium ", J. Appl. Phys., 47 52.
48 (1976) and the like are known. Examples of the MIM type include C.I. A. Mead, "The tunnel-em
issue amplifier, J.I. Appl. P
hys. , 32 646 (1961) and the like are known. As an example of the surface conduction electron-emitting device type, see, I.
Elinson, RadioEng. Electro
n Phys. 10 (1965) and so on. The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current is applied to a thin film having a small area formed on a substrate in parallel with the film surface. Examples of the surface conduction electron-emitting device include a device using an SnO ₂ thin film by Elinson et al. And a device using an Au thin film [G. Dittme
r: “Thin Solid Films”, 9 31
7 (1972)], by In ₂ O ₃ / SnO ₂ thin film [M. Hartwell and C.M. G. FIG. Fons
tad: "IEEE Trans. ED Con
f. 519 (1975)], by a carbon thin film [Hiraki Araki et al .: Vacuum, Vol. 26, No. 1, p. 22 (1)
983)] has been reported. As a typical device configuration of these surface conduction electron-emitting devices, the aforementioned M.S. The Hartwell device configuration is shown in FIG. 201 in the figure
Is a substrate. Reference numeral 204 denotes a conductive thin film, which is formed of a metal oxide thin film or the like formed by sputtering on an H-shaped pattern, and the electron emission portion 205 is formed by an energization process called energization forming described later. The device electrode spacing L ′ in the figure is set to 0.5 to 1 mm, and W ″ is set to 0.1 mm. The position and shape of the electron emitting portion 205 are schematically shown.

Conventionally, in these surface conduction electron-emitting devices, it has been general that the electron-emitting portion 205 is formed in advance by conducting a current called a conductive forming process on the conductive thin film 204 before emitting electrons. That is, the energization forming means that a direct current voltage or a very slow rising voltage, for example, about 1 V / min is applied to both ends of the electroconductive thin film 204 to energize the electroconductive thin film 204 to locally break, deform or alter the electroconductive thin film, and thereby electrically. That is, the electron emitting portion 205 is formed in a high resistance state. The electron emission unit 205
A crack is generated in a part of the conductive thin film 204, and electrons are emitted from the vicinity of the crack. The surface conduction electron-emitting device that has been subjected to the energization forming treatment is the above-mentioned conductive thin film 204.
Electrons are emitted from the electron emitting portion 205 by applying a voltage to the element and passing a current through the element.

Since the surface conduction electron-emitting device described above has a simple structure and is easy to manufacture, it has an advantage that a large number of devices can be arrayed over a large area. Therefore, various applications that can make full use of this feature are being researched. For example, a charged beam source, a display device such as an image display device may be used.

In the above-mentioned display device and the like, as a method of dissipating heat generated by a display panel or the like due to energization of an electron-emitting device, only a general method such as natural heat dissipation or forced air cooling is used.

[0006]

However, in recent years,
Along with the increase in size and thickness of the flat image display device, the following problems have been encountered in the conventional methods such as natural heat dissipation and forced air cooling. (1) The display panel cannot be cooled efficiently, and heat generated in the electron-emitting device portion due to driving causes thermal strain in the display panel, resulting in low reliability of the device. (2) The installation space for the radiation fins for heat radiation of the display panel, the air-cooling fan, and the like hinders reduction in thickness.

An object of the present invention is to provide an image forming apparatus that solves the above problems.

[0008]

In order to solve the above-mentioned problems, the present invention provides "a back plate having an electron-emitting device portion using an electron-emitting device and an image-forming portion facing the electron-emitting portion. An image forming apparatus having a display panel in which a front plate and a frame between the back plate and the front plate and surrounding the electron-emitting device section and the image forming section are hermetically sealed with a sealing material. The image forming apparatus is characterized in that the back plate has an area projecting from the outer periphery of the frame, and a heating member for heating the area is installed in contact with the area projecting from the outer periphery of the frame. Is provided,
(1) The heating member is composed of an electric component that generates heat and a heat conducting member that contacts the electric component, and the heat conducting member is in contact with the protruding portion, (2) Heat generation of (1) (3) The heating member is installed in contact with the outer wall of the frame together with the portion of the back plate projecting from the outer periphery of the frame. (3) The heating member of (3) is composed of an electric component that generates heat and a heat conducting member that contacts the electric component, and the heat conducting member is in contact with the protruding portion and the outer wall of the frame. The electron-emitting device is a surface conduction electron-emitting device, and the electric circuit board of (6) and (2) is an electric circuit board for driving a display panel.

According to the present invention, the temperature of the display panel, especially the back plate, can be made uniform. Further, it is not necessary to use a radiation fin or an air cooling fan for the display panel.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an image forming apparatus of the present invention will be described with reference to FIGS. FIG. 1 is a plan view of a display panel unit, in which 1 is a display panel unit, 2 is a front plate, 20 is an image forming portion, 3 is a back plate, 5 is wiring, and the front plate 2, the back plate 3 and a frame ( The display panel 10 which is a closed container is formed from (not shown). The wiring 5 is used to supply a drive signal from the electric circuit board to the electron-emitting device on the back plate 3. The image forming portion 20 provided inside the display panel 10 forms an image by electrons emitted from the emitting element. Next, description will be given with reference to FIG. 2 which is a cross section taken along the line AA of FIG.

FIG. 2 is a sectional view of the above-mentioned display panel unit, 1 is a display panel unit, 10 is a display panel,
2 is a front plate, 20 is an image forming part, 3 is a back plate, 30 is an electron-emitting device part, 4 is a frame, 5 is wiring, 6 is an electric circuit board,
Reference numeral 7 is a heat generating electric component, 8 is an electric component, and 9 is a heat conducting member.

A display panel 10 which is an airtight container is formed from the front plate 2, the rear plate 3 and the frame 4, and inside thereof, an image forming section 20 on the front plate 2 and an electron-emitting device section on the rear plate 3 are formed. 30 are provided so as to face each other. On the electric circuit board 6, electric components 7 that generate heat
Other electric components 8 are mounted on the outside and inside. The electric connection between the electric circuit board 6 and the display panel 10 is made by the heat conducting member 9 in the electric component 7, and the electric connection between the electric circuit board 6 and the display panel 10 is made by the wiring 5.

The drive signal is transmitted from the electric circuit board 6 through the wiring 5 to the electron-emitting device section 30 on the back plate 3 of the display panel 10, and electrons are emitted from the electron-emitting device to cause the image forming section 2 to emit.
An image is formed at 0. The image forming apparatus is completed by housing the display unit 1 in the outer box.

FIG. 3 is a view showing the relationship between the display panel of the above-mentioned display panel unit and the electric circuit board. 10 is a display panel, 2 is a front plate, 20 is an image forming portion, 3 is a back plate, and 4 is a back plate.
Is a frame, 6 is an electric circuit board, 7 is an electric part that generates heat (for example, a large current is passed, a high voltage is applied, is switched), and 8 is an electric part that does not generate heat relatively (for example, performs signal processing). Things that make a reference signal). The display panel is composed of a front plate 2, a rear plate 3 and a frame 4, and the image forming section 20 is formed on the front plate 2 inside the display panel.
Is provided. On the electric circuit board 6, a heat-generating electric component 7 is mounted on the outer periphery and other electric components 8 are mounted on the inner side.

The electron-emitting device used in the present invention is preferably a surface conduction electron-emitting device which has a simple structure and is easy to manufacture. There are basically two types of surface conduction electron-emitting devices: a planar surface conduction electron-emitting device and a vertical surface conduction electron-emitting device.

The structure of a basic surface conduction electron-emitting device is schematically shown in FIGS. 6A and 6B as a plan view and a sectional view. In FIG. 6, 101 is a substrate, 102 and 103 are device electrodes, 104 is a conductive thin film, and 105 is an electron emitting portion. As the substrate 101, quartz glass, glass having a low content of impurities such as Na, soda lime glass, a glass substrate having SiO ₂ formed on its surface, and a ceramic substrate such as alumina are used. A general conductor is used as a material for the device electrodes 102 and 103. For example, Ni, Cr, Au,
A printed conductor composed of a metal or an alloy such as Mo, W, Pt, Ti, Al, Cu, Pd and a metal or a metal oxide such as Pd, Ag, Au, RuO ₂ , Pd-Ag and glass, and the like, It is appropriately selected from a transparent conductor such as In ₂ O ₃ —SnO ₂ and a semiconductor material such as polysilicon. The device electrode spacing L is preferably several hundreds of angstroms to several hundreds of micrometers. Further, it is desirable that the voltage applied between the device electrodes is low, and since it is required to produce it with good reproducibility, the preferred device electrode interval is several micrometers to several tens of micrometers. The device electrode length W is preferably several micrometers to several hundreds of micrometers in view of the resistance value of the electrodes and electron emission characteristics, and the film thickness of the device electrodes 102 and 103 is preferably several micrometers to several micrometers. The substrate 101 is not the structure shown in FIG.
The conductive thin film 104 and the electrodes of the device electrodes 102 and 103 may be formed in this order on the structure.

The conductive thin film 104 has good electron emission characteristics.
A fine particle film composed of fine particles to obtain is particularly preferred.
The thickness of the film is the step size for the device electrodes 102 and 103.
The range, the resistance value between the device electrodes 102 and 103, and
Depending on the energization forming conditions, etc.
But preferably from a few angstroms to a few thousand angstroms
Loam, particularly preferably 5 to 10 angstroms
It is 00 angstrom. Its sheet resistance is 10
3 to 10 7 ohm / □ (Ω / Sq.)
You. The material forming the conductive thin film 104 is Pd, Pt,
Ru, Ag, Au, Ti, In, Cu, Cr, Fe, Z
n, Sn, Ta, W, Pb and other metals, PdO, SnO
_Two , In_Two O_Three , PbO, Sb_Two O_Three Oxides such as Hf
B_Two , ZrB_Two , LaB ₆ , CeB₆ , YB_Four , GdB
_Four Borides such as TiC, ZrC, HfC, Tac, Si
Carbides such as C and WC, nitriding of TiN, ZrN, HfN, etc.
Examples include materials, semiconductors such as Si and Ge, and carbon.
The above-mentioned fine particle film is a film in which a plurality of fine particles are aggregated.
As a result of its fine structure, fine particles were dispersed and arranged individually.
Not only the state, but the particles are adjacent to each other or overlap
It refers to a film in a matched state (including islands),
Particle size is from a few angstroms to a few thousand angstroms
Yes, preferably from 10 to 200 on
Gustrom.

The electron emitting portion 105 is a high resistance crack formed in a part of the conductive thin film 104, and is formed by energization forming or the like. Further, the cracks may have conductive fine particles having a particle diameter of several angstroms to several hundred angstroms. The conductive fine particles are the conductive thin film 104.
It contains at least a part of the elements constituting the.
In addition, the electron emitting portion 105 and the conductive thin film 104 in the vicinity thereof
May have carbon and carbon compounds.

Next, FIG. 7 is a schematic sectional view showing the structure of a basic vertical surface conduction electron-emitting device. 7, the same components as those in FIG. 6 are designated by the same reference numerals. 111 is a step forming portion. Substrate 101, device electrodes 102 and 103, conductive thin film 104, electron emission portion 10
5 can be made of the same material as that of the above-mentioned flat surface conduction electron-emitting device, the step forming portion 111 is made of an insulating material, and the film thickness of the step forming portion 111 is the flat surface described above. It corresponds to the device electrode distance L of the conduction electron-emitting device. The spacing is tens of micrometers rather than hundreds of angstroms. The distance can be controlled by the manufacturing method of the step forming portion and the voltage applied between the device electrodes, but it is preferably several hundred angstroms to several micrometers. The conductive thin film 104 is the device electrode 102, 1
03 and the step forming portion 111 are formed after they are formed, so that they are laminated on the device electrodes 102 and 103. Although the electron emitting portion 105 is shown to be linearly formed in the step forming portion 111 in FIG. 7, the shape and position are not limited to this, depending on the production conditions, energization forming conditions, and the like. Absent.

There are various methods for manufacturing the above-mentioned surface conduction electron-emitting device, one example of which is shown in FIG.
Hereinafter, a method of manufacturing the electron source substrate will be described with reference to FIGS. 6 and 8. In FIG. 8, the same members as those in FIG. 6 are designated by the same reference numerals.

1) After thoroughly cleaning the substrate with a detergent, pure water and an organic solvent, a device electrode material is deposited by a vacuum deposition method, a sputtering method or the like. Then, the device electrodes 102 and 103 are formed on the substrate by the photolithography technique (FIG. 8A).

2) An organic metal solution is applied to the substrate 101 provided with the device electrodes 102 and 103 and left to stand to form an organic metal thin film. The organometallic solution referred to here is a solution of an organometallic compound whose main element is the metal forming the conductive film 104. Then, the organometallic thin film is heated and baked, and is patterned by lift-off, etching or the like to form the conductive thin film 104 (FIG. 8).
(B)). Although the description has been given here by using the coating method of the organic metal solution, the present invention is not limited to this, and the vacuum deposition method, the sputtering method, the chemical vapor deposition method, the dispersion coating method, the dipping method,
It can also be formed by a spinner method or the like.

3) Subsequently, energization processing called energization forming is performed. Energization forming is performed by device electrodes 102, 1
A power source (not shown) is applied between the electrodes 03 to locally destroy, deform or alter the conductive thin film 104 to form a portion having a changed structure. The part where the structure is locally changed is called an electron emission part 105 (FIG. 8).
(C)). FIG. 9 shows an example of the voltage waveform of energization forming. A pulse waveform is particularly preferable as the voltage waveform, and when a voltage pulse with a constant pulse peak value is continuously applied (see FIG. 9).
a) and the case of applying a voltage pulse while increasing the pulse peak value (FIG. 9b). First, the case where the pulse peak value is a constant voltage (FIG. 9A) will be described.

In FIG. 9a, T1 and T2 are the pulse width and pulse interval of the voltage waveform, where T1 is 1 microsecond to 1
0 milliseconds, T2 is 10 microseconds to 100 milliseconds,
The peak value of the triangular wave (peak voltage at the time of energization forming) is appropriately selected according to the form of the surface conduction electron-emitting device, and for several seconds in an appropriate vacuum degree, for example, in a vacuum atmosphere of about 10 −5 torr. Apply several tens of minutes. The waveform applied between the electrodes of the element is not limited to a triangular wave, and a desired waveform such as a rectangular wave may be used. T1 in FIG. 9b
And T2 are the same as those in FIG. 9a, and the peak value of the triangular wave (peak voltage during energization forming) is increased by, for example, about 0.1 V step and applied in an appropriate vacuum atmosphere. In the energization forming process in this case, the element current is measured during the pulse interval T2 at a voltage that does not locally break or deform the conductive thin film 104, for example, a voltage of about 0.1 V, and the resistance value is obtained. For example, when forming a resistance of 1 M ohm or more, the energization forming is finished.

4) Next, it is desirable to perform a process called an activation process on the element which has completed the energization forming. The activation step is, for example, 10 −4 to 10 −5 tor.
Similar to the energization forming, it is a process of repeatedly applying a voltage pulse having a constant pulse peak value at a vacuum degree of about r, and carbon and / or
Alternatively, by depositing a carbon compound on the conductive thin film, the device current If,
This is a process of significantly changing the emission current Ie. The activation process is completed, for example, when the emission current Ie is saturated while measuring the device current If and the emission current Ie. Further, it is preferable that the applied voltage pulse is an operation drive voltage.
Here, carbon and / or carbon compound is graphite (indicating both single and polycrystalline) amorphous carbon (indicating a mixture of amorphous carbon and polycrystalline graphite), etc., and its film thickness is 500 angstroms or less. Is preferable, and more preferably 300 angstroms or less.

5) It is preferable to place the electron-emitting device thus produced in an energization forming step and an activation step under an atmosphere having a higher degree of vacuum than the degree of vacuum to drive it.
In addition, it is desirable to operate after heating to 80 ° C. to 150 ° C. in an atmosphere of a higher degree of vacuum. The degree of vacuum higher than the degree of vacuum obtained by the energization forming step and activation is, for example, a degree of vacuum of about −10 −6 or higher, more preferably an ultrahigh vacuum system, in which carbon and carbon compounds are newly added. The degree of vacuum is such that it is hardly deposited on the conductive thin film. By doing so, the device current If and the emission current Ie can be stabilized.

FIG. 1 is a schematic configuration diagram of a measurement / evaluation apparatus for measuring electron emission characteristics of an element having the configuration shown in FIG.
0 is shown. 10, the same symbols as those in FIG. 6 indicate the same things. 121 is a power source for applying the device voltage Vf to the electron-emitting device, and 120 is the device electrodes 102 and 103.
An ammeter for measuring the device current If flowing through the conductive thin film 104 between them, 124 an anode electrode for capturing the emission current Ie emitted from the electron emission portion of the device, 123
Is a high voltage power supply for applying a voltage to the anode electrode 124, 122 is an ammeter for measuring the emission current Ie emitted from the electron emission portion 105 of the device, 125 is a vacuum device, and 126 is an exhaust pump.

Next, the image forming apparatus of the present invention will be described. The electron source substrate used in the image forming apparatus is formed by arranging a plurality of surface conduction electron-emitting devices on the substrate. The arrangement method of the surface conduction electron-emitting devices is to arrange the surface conduction electron-emitting devices in parallel, and connect both ends of each device with wiring in a ladder arrangement (hereinafter referred to as a ladder-type arrangement electron source substrate), There is a simple matrix arrangement (hereinafter referred to as a matrix type arrangement electron source substrate) in which an X-direction wiring and a Y-direction wiring are respectively connected to a pair of device electrodes of the surface conduction electron-emitting device. An image forming apparatus having a ladder-type electron source substrate requires a control electrode (grid electrode) which is an electrode for controlling the flight of electrons from an electron-emitting device.

The structure of the electron source constructed based on this principle will be described below with reference to FIG. 131 is an electron source substrate, 132 is X-direction wiring, 133 is Y-direction wiring, 1
Reference numeral 34 is a surface conduction electron-emitting device, and 135 is a wire connection.
The surface conduction electron-emitting device 134 may be either the flat type or the vertical type described above. In the figure, the substrate used as the electron source substrate 131 is the above-mentioned glass substrate or the like, and the shape is appropriately set according to the application. The m number of X-direction wirings 132 are composed of D _x1 , D _x2 , ... D _xm , and the Y-direction wiring 133 is composed of n lines of D _y1 , D _y2 , ... D _yn . The material, film thickness, and wiring width of these wirings are appropriately set so that a substantially uniform voltage is supplied to a large number of surface conduction elements. The m wirings in the X direction 132 and the n wirings in the Y direction 133 are electrically separated by an interlayer insulating layer (not shown) to form a matrix wiring. (M and n are both positive integers) The interlayer insulating layer (not shown) is formed in a desired region on the entire surface or a part of the substrate 131 on which the X-direction wiring 132 is formed.
The X-direction wiring 132 and the Y-direction wiring 133 are drawn out as external terminals. Furthermore, the surface conduction electron-emitting device 13
4 element electrodes (not shown) have m number of X-direction wirings 132 and n
The book is electrically connected to the Y-direction wiring 133 by a connection 135. The surface conduction electron-emitting device may be formed either on the substrate or on an interlayer insulating layer (not shown).
The X-direction wiring 132 will be described in detail later, but a scanning signal generating means (not shown) for applying a scanning signal for scanning a row of the surface conduction electron-emitting devices 134 arranged in the X direction according to an input signal. Is electrically connected to. on the other hand,
The Y direction wiring 133 is electrically connected to a modulation signal generating means (not shown) for applying a modulation signal for modulating each row of the surface conduction electron-emitting devices 134 arranged in the Y direction according to an input signal. It is connected to the. Further, the drive voltage applied to each element of the surface conduction electron-emitting device is supplied as a difference voltage between the scanning signal and the modulation signal applied to the element. With the above configuration, individual elements can be selected and driven independently by using only simple matrix wiring.

Next, an image forming apparatus using the matrix type arrangement electron source substrate produced as described above will be described with reference to FIGS. 12, 13 and 14. 12 is a basic configuration diagram of the image forming apparatus, FIG. 13 is a fluorescent film, and FIG.
4 shows a block diagram of a drive circuit for displaying in accordance with an NTSC television signal, and represents an image forming apparatus including the drive circuit.

In FIG. 12, 131 is an electron source substrate having an electron-emitting device formed on the substrate, and 141 is an electron source substrate 131.
A rear plate 146, a face plate having a fluorescent film 144, a metal back 145, etc. formed on the inner surface of a glass substrate 143, a support frame 142, and a rear plate 141. These members constitute an envelope 148. To be done. Reference numeral 134 corresponds to the electron emitting portion in FIG.
Reference numerals 132 and 133 denote X-direction wiring and Y-direction wiring connected to the pair of device electrodes of the surface conduction electron-emitting device.

The envelope 148 comprises the face plate 146, the support frame 142 and the rear plate 141 as described above, and the rear plate 141 is mainly for the purpose of reinforcing the strength of the electron source substrate 131. Because it is provided,
When the electron source substrate 131 itself has sufficient strength, the separate rear plate 141 is not necessary, and the support frame 142 is directly provided on the electron source substrate 131, and the face plate 146, the support frame 142, and the electron source substrate 131 are used. The envelope 148 may be configured.

Reference numeral 152 in FIG. 13 is a phosphor. Phosphor 1
In the case of monochrome, 52 is composed of only the phosphor, but in the case of a color phosphor film, it is composed of a black conductive material 151 called a black stripe or a black matrix depending on the arrangement of the phosphor and a phosphor 152. In the case of color display, the purpose of providing the black stripes and the black matrix is each phosphor 1 of the three primary color phosphors required.
That is, the colored portions between 52 are made black so as to make the color mixture and the like inconspicuous and to suppress the deterioration of the contrast due to the reflection of external light on the fluorescent film 144. As a material for the black stripe, a material containing graphite as a main component is usually often used, but the material is not limited to this as long as the material has conductivity and little transmission and reflection of light. As a method of applying the phosphor to the glass substrate 143, a precipitation method or a printing method is used regardless of monochrome or color. In addition, a normal metal back 145 is provided on the inner surface side of the fluorescent film 144 (FIG. 12).
(FIG. 12) is provided. The purpose of the metal back is to improve the brightness by specularly reflecting the light toward the inner surface side of the light emission of the phosphor to the face plate 146 side, to act as an electrode for applying an electron beam acceleration voltage, This is to protect the phosphor from the damage caused by the collision of negative ions generated inside the container. The metal back can be produced by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film after producing the fluorescent film, and then depositing Al by vacuum evaporation or the like. The face plate 146 is provided with a fluorescent film 14 in order to further increase the conductivity of the fluorescent film 144.
A transparent electrode (not shown) may be provided on the outer surface side of 4. The envelope 148 is connected to an exhaust pipe (not shown) to the 10 −7 th tor.
The degree of vacuum is set to about r and sealing is performed. Further, a getter process may be performed to maintain the degree of vacuum after the envelope 148 is sealed. This is a predetermined position (not shown) in the envelope 148 immediately before or after the envelope 148 is sealed by a heating method such as resistance heating or high frequency heating.
This is a process of heating the getter arranged in the above to form a vapor deposition film. The getter usually has Ba as a main component, and due to the adsorption action of the vapor deposition film, for example, 1 × 10 −5 torr.
That is, the degree of vacuum of 1 × 10 −7 torr is maintained. The steps after forming the surface conduction electron-emitting device are appropriately set.

Next, referring to the block diagram of FIG. 14, a schematic structure of a drive circuit for displaying a television on the basis of an NTSC system television signal in an image forming apparatus constructed by using a matrix type electron source substrate will be described. explain. Reference numeral 161 is the display panel, 162 is a scanning circuit, 163.
Is a control circuit, 164 is a shift register, 165 is a line memory, 166 is a synchronizing signal separation circuit, 167 is a modulation signal generator, and Vx and Va are DC voltage sources.

The function of each unit will be described below. The display panel 161 to _oy1 no D _oxm and terminal D to no terminal D _ox1 connected to an external electric circuit via a D _Oyn and high voltage terminal Hv. Among these terminals, the terminals D _ox1 to D _oxm are provided with an electron source provided in the image forming apparatus, that is, M.
A scanning signal is applied to sequentially drive the surface conduction electron-emitting device groups, which are arranged in a matrix of rows and N columns, row by row (N elements).

On the other hand, a modulation signal for controlling the output electron beam of each element of the surface conduction electron-emitting devices of one row selected by the scanning signal is applied to the terminals D _y1 to D _yn . The high voltage terminal Hv is supplied with a DC voltage of, for example, 10 [kV] from the DC voltage source Va, which is sufficient to excite the phosphor into the electron beam output from the surface conduction electron-emitting device. It is an accelerating voltage for applying energy.

Next, the scanning circuit 162 will be described. The circuit has M switching elements inside (indicated by S ₁ to S _m in the figure), and each switching element is an output voltage of the DC voltage source Vx or 0.
One of [V] (ground level) is selected and electrically connected to the terminals D _x1 to D _{xm of the} display panel 161. Each of the switching elements S ₁ to S _m operates based on the control signal Tscan output from the control circuit 163, but can actually be configured by combining switching elements such as FETs.

It should be noted that the DC voltage source Vx is such that the driving voltage applied to an unscanned element is equal to or lower than the electron emission threshold voltage based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting element. It is set to output a constant voltage such that

The control circuit 163 has a function of matching the operation of each part so that an appropriate display is performed based on an image signal input from the outside. Based on the synchronization signal Tsync sent from the synchronization signal separation circuit 166 described below, Tscan, Tsft, and Tm are supplied to the respective units.
ry control signals are generated.

The sync signal separation circuit 166 is a circuit for separating the sync signal component and the luminance signal component from the NTSC system television signal input from the outside, and can be constructed by using a frequency separation (filter) circuit. The sync signal separated by the sync signal separation circuit 166 is composed of a vertical sync signal and a horizontal sync signal as is well known, but here, for convenience of explanation, it is shown as a Tsync signal. on the other hand,
The luminance signal component of the image separated from the television signal is referred to as a DATA signal for the sake of convenience.
4 is input.

The shift register 164 performs serial / parallel conversion of the DATA signal serially input in time series for each line of the image, and operates based on the control signal Tsft sent from the control circuit 163. . (That is, the control signal Tsft corresponds to the shift register 1
In other words, the shift clock may be 64. ) The data of one line of the serial / parallel-converted image (corresponding to the drive data of the electron-emitting device N element) is I _d1.
To I _dn as N parallel signals, the shift register 1
It is output from 64.

The line memory 165 is a storage device for storing data for one line of an image for a required time,
The contents of I _d1 to I _dn are stored according to the control signal Tmry sent from the control circuit 163. The stored contents are output as I _d1 to I _dn and the modulation signal generator 1 is output.
It is input to 67.

The modulation signal generator 167 outputs the image data I
A signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of _d1 to I _dn , and an output signal of which is a surface conduction type electron emission in the display panel 161 through terminals _Doy1 to _Doyn. Applied to the device.

The electron-emitting device according to the present invention has an emission current I
It has the following basic characteristics for e. That is, the electron emission has a clear threshold voltage Vth, and the electron emission occurs only when a voltage equal to or higher than Vth is applied. For voltages above the electron emission threshold, the emission current also changes in accordance with changes in the voltage applied to the device. The electron emission threshold voltage Vth can be changed by changing the material, structure, and manufacturing method of the electron emission element.
There is a case where the value of V and the degree of change of the emission current with respect to the applied voltage change, but in any case, the following can be said.

That is, when a pulsed voltage is applied to this element, for example, electron emission does not occur even if a voltage below the electron emission threshold is applied, but when a voltage above the electron emission threshold is applied, the electron beam is Is output. At that time, first, the intensity of the output electron beam can be controlled by changing the peak value Vm of the pulse. Second, it is possible to control the total amount of charges of the electron beam output by changing the pulse width Pw. Therefore, as a method of modulating the electron-emitting device according to the input signal, there are a voltage modulation method, a pulse width modulation method, and the like. To implement the voltage modulation method, the modulation signal generator 167 is used.
For this, a voltage modulation type circuit is used that generates a voltage pulse of a fixed length, but appropriately modulates the peak value of the pulse according to the input data. In order to implement the pulse width modulation method, the modulation signal generator 167 is a pulse width modulation method that generates a voltage pulse with a constant peak value but appropriately modulates the width of the voltage pulse according to the input data. It uses a circuit.

By the series of operations described above, the image forming apparatus of the present invention can display the television using the display panel 161. Although not particularly described in the above description, the shift register 164 and the line memory 165 may be of a digital signal type or an analog signal type, and the point is that serial / parallel conversion and storage of image signals are performed at a predetermined speed. It should be done. When the digital signal type is used, the output signal DATA of the sync signal separation circuit 166
Needs to be converted into a digital signal, but this is possible if an A / D converter is provided at the output of 166. Further, in relation to this, the circuit used for the modulation signal generator 167 is slightly different depending on whether the output signal of the line memory 165 is a digital signal or an analog signal.

First, the case of digital signals will be described.
In the voltage modulation method, for the modulation signal generator 167, for example, a well-known D / A conversion circuit may be used, and an amplification circuit or the like may be added if necessary. In the case of the pulse width modulation method, the modulation signal generator 167 includes, for example, a high-speed oscillator, a counter that counts the number of waves output by the oscillator, and a comparator that compares the output value of the counter with the output value of the memory. It can be configured by using a circuit in which (comparators) are combined. If necessary, an amplifier for voltage-amplifying the pulse-width-modulated modulation signal output from the comparator up to the drive voltage of the surface conduction electron-emitting device may be added.

Next, the case of an analog signal will be described.
In the voltage modulation method, for the modulation signal generator 167, for example, an amplifier circuit using a well-known operational amplifier may be used, and a level shift circuit or the like may be added if necessary. In the case of the pulse width modulation method, for example, a well-known voltage control type oscillation circuit (VCO) may be used, and if necessary, an amplifier for amplifying the voltage to the drive voltage of the surface conduction electron-emitting device may be added. Good.

In the image forming apparatus completed as described above, each of the electron-emitting devices has terminals outside the container D _ox1 to D _ox1.
oxm, to no D _Oy1 through D _Oyn, by applying a voltage, is emitting electrons through the high voltage terminal Hv, a high voltage is applied to the metal back 145 or a transparent electrode (not shown) to accelerate the electron beam, the fluorescent film An image can be displayed by colliding with 144 and exciting and emitting light. The configuration described above is a schematic configuration necessary for manufacturing a suitable image forming apparatus used for display and the like. For example, detailed portions such as materials of each member are not limited to those described above. Appropriate selection is made to suit the use of the device. Also, although the NTSC system has been given as an example of the input signal, it is not limited to this, and various systems such as the PAL and SECAM systems may be used, and a TV signal (for example, MUSE) composed of a large number of scanning lines may be used. A high-definition TV) system such as a system may be used.

Next, the ladder type electron source substrate and the image forming apparatus using the same will be described with reference to FIGS. In FIG. 15, 170 is an electron source substrate, 1
Reference _numeral 71 is an electron-emitting device, and D _{x1 to} D _{x10 of} 172 are common wirings connected to the electron-emitting device. Electron-emitting device 17
A plurality of Nos. 1 are arranged in parallel in the X direction on the substrate 170. (This is called an element row). A plurality of this element row is arranged on the substrate to form a ladder type electron source substrate. By appropriately applying a drive voltage between the common wirings of each element row, each element row can be independently driven. That is, a voltage equal to or higher than the electron emission threshold is applied to the element row that emits an electron beam,
A voltage equal to or lower than the electron emission threshold may be applied to the element row that does not emit the electron beam. Also, common wiring D between each element row
For example, _{x2 to} D _x9 may have the same wiring as D _x2 and D _x3 .

FIG. 16 is a view showing the structure of an image forming apparatus provided with a ladder-type electron source. 180 is a grid electrode, 181 is a hole through which electrons pass, 182
Is an external terminal made of D _ox1 , D _ox2 ... D _oxm ,
183 is G ₁ , G ₂ connected to the grid electrode 180,
.., _Gn , and 170 is an electron source substrate in which common wiring between the element rows is the same wiring as described above. The same reference numerals as those in FIGS. 12 and 15 indicate the same members. The image forming apparatus having the above-mentioned simple matrix arrangement (see FIG.
The difference from 2) is that the grid electrode 180 is provided between the electron source substrate 170 and the face plate 146.

A grid electrode 180 is provided between the substrate 170 and the face plate 146. The grid electrode 180 is capable of modulating the electron beam emitted from the surface conduction electron-emitting device, and passes the electron beam through the stripe-shaped electrodes provided orthogonal to the ladder-shaped element rows. Circular holes 181 are provided one by one corresponding to each element. The shape and installation position of the grid are not necessarily as shown in FIG. 16, and a large number of passage openings may be formed in a mesh as openings, and may be provided around or near the surface conduction electron-emitting device. . The external terminal 182 and the grid external terminal 183 are electrically connected to a control circuit (not shown).

In this image forming apparatus, the modulation signals for one image line are simultaneously applied to the grid electrode columns in synchronization with the sequential driving (scanning) of the element rows one column at a time.
The irradiation of each electron beam to the phosphor can be controlled to display an image line by line. According to the present invention, it is possible to provide an image forming apparatus suitable for not only a display device for television broadcasting but also a display device such as a video conference system and a computer. Further, it can be used as an image forming apparatus as an optical printer including a photosensitive drum or the like. Further, it can be applied not only to surface conduction electron-emitting devices as electron-emitting devices but also to cold cathode electron sources such as MIM electron-emitting devices and field emission electron-emitting devices.
Further, it can be applied to an image forming apparatus using a thermoelectron source.

[0054]

The present invention will be described in more detail with reference to the following examples.

Example 1 An example showing the features of the present invention is shown in FIGS. 1 is a plan view of the display panel unit, and FIG.
2 is a sectional view of the display panel unit taken along the line AA in FIG. In these drawings, 1 is a display panel unit, 10 is a display panel, 2 is a front plate made of soda lime glass, 20 is an image forming portion on the front plate 2 on which phosphors are formed, and 3 is a back plate made of soda lime glass. A face plate, 30 is an electron-emitting device portion on the back plate 3 on which the above-mentioned electron-emitting devices are formed, 4 is a frame made of soda-lime glass, 5 is wiring made of a flexible substrate, and 6 is an electric circuit for driving the electron-emitting device. An electric circuit board on which is formed, 7 is an electric component such as a transistor that generates heat when the electron-emitting device is driven, 8 is an electric component such as a voltage reference that does not generate heat relatively, and 9 is a component that efficiently heats the electric component 7. It is a heat conductive member made of grease for transmitting to the face plate.

The front plate 2 and the rear plate 3 are sealed with glass frit through the frame 4 in a state where the front plate 2 and the rear plate 3 are positioned relative to each other to form a display panel 10 which is a closed container. Inside the display panel 10, an image forming unit 20 is provided on the front plate 2 and an electron-emitting device unit 30 is provided on the rear plate 3 so as to face each other. Electric components 7 that generate heat on the electric circuit board 6
The other electric component 8 is mounted on the outside of the electron-emitting device section 30. Electric circuit board 6 and display panel 1
The mechanical connection with 0 is made by the heat conducting member 9 in the portion of the electric component 7, and the electric connection between the electric circuit board 6 and the display panel 10 is made by the wiring 5. The image forming apparatus is completed by housing the display unit 1 in the outer box.

FIG. 3 is a view showing the relationship between the display panel of the above-mentioned display panel unit and the electric circuit board. 10 is a display panel, 2 is a front plate, 20 is an image forming portion, 3 is a rear plate, 4
Is a frame, 6 is an electric circuit board, 7 is an electric component that generates heat, and 8 is another electric component.

The display panel 10 is composed of a front plate 2, a rear plate 3 and a frame 4, and an image forming section 20 is provided on the front plate 2 inside thereof. Electric components 7 that generate heat are installed on the outer periphery of the electric circuit board 6 and other electric components 8
Is installed inside. The display panel 10 and the electric circuit board 6 are assembled as shown in FIG. At that time, electrical parts 7
A heat conducting material 9 (not shown) is inserted between the back plate 3 of the display panel 10 and the back panel 3.

The drive signal of the image forming apparatus is the electric circuit board 6
Is transmitted to the electron emission element section 30 on the back plate 3 of the display panel 10 through the wiring 5, and electrons are emitted from the electron emission element to form an image on the image forming section 20. When the image forming apparatus is driven, the heat of the electron emitting portion and the heat of the electric component 7 generated by the driving are substantially evenly distributed in the back plate of the display panel, and no thermal distortion is observed. It was

The form of the electric circuit board is not limited to that of this embodiment, and for example, a structure of a plurality of electric circuit boards in which the electric components 7 and 8 are separately mounted may be used, and the electric circuit board may be constructed according to its function. Can be appropriately selected.

Embodiment 2 As a second embodiment which shows the features of the present invention, a description will be given with reference to FIGS. 4 and 5. 4 is a plan view of the display panel unit, and FIG. 5 is a BB of the display panel unit FIG.
It is sectional drawing. In these drawings, 1 is a display panel unit, 10 is a display panel, 2 is a front plate made of soda lime glass, 20 is an image forming portion on the front plate 2 on which phosphors are formed, and 3 is a back plate made of soda lime glass. A face plate, 30 is an electron-emitting device portion on the back plate 3 on which the above-mentioned electron-emitting devices are formed, 4 is a frame made of soda-lime glass, 5 is wiring made of a flexible substrate, and 6 is an electric circuit for driving the electron-emitting device. , 60 is an electric circuit board on which an electric component that generates heat is mounted, 7 is an electric component such as an IC that generates heat when the electron-emitting device is driven, 8 is an electric component such as a signal processing circuit, and 9 is Is a heat conducting member made of a paste for efficiently transmitting the heat of the electric component 7 to the back plate.

The front plate 2 and the rear plate 3 are sealed with a glass frit through the frame 4 in a state where the front plate 2 and the rear plate 3 are positioned relative to each other to form a display panel 10 which is a closed container. Inside the display panel 10, an image forming unit 20 is provided on the front plate 2 and an electron-emitting device unit 30 is provided on the rear plate 3 so as to face each other. An electric component 7 that generates heat is mounted on the electric circuit board 60, and other electric components are mounted on the electric circuit board 6. The electric component 7 on the electric circuit board 60 is in contact with the outside of the back plate 3 of the display panel 10 and the frame 4 via the heat conducting member 9. Electric circuit boards 6 and 60
The wiring 5 electrically connects the display panel 10 with the display panel 10. The image forming apparatus is completed by housing the display unit 1 in the outer box.

The drive signal for the image forming apparatus is the electric circuit board 6
And 60 from the rear panel 3 of the display panel 10 via the wiring 5.
The electrons are transmitted to the upper electron-emitting device section 30 and the electrons are emitted from the electron-emitting element to form an image on the image forming section 20. When the image forming apparatus is driven, the heat of the electron emitting portion and the heat of the electric component 7 generated due to the driving are substantially evenly distributed in the back plate of the display panel, and the problematic thermal strain does not occur. I couldn't see it.

The material of each component is not limited to the above-mentioned embodiment, but the back plate is made of glass or ceramics, the front plate is made of glass or the like, the frame is made of glass or ceramics, or the like. The material is heat conductive rubber, etc.
It can be appropriately selected according to its function.

Further, if there is a margin in the installation location of the device, a structure using a conventional radiation fin or an air-cooling fan is also possible.

[0066]

As described above, in the image forming apparatus of the present invention, since the display panel is not thermally distorted, it is possible to suppress the warp of the panel and provide a highly reliable image forming apparatus. it can. Furthermore, since it is not necessary to attach a radiation fin or an air cooling fan, it is possible to provide a compact and thin image forming apparatus.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a display panel unit according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of the display panel unit of the first embodiment of the present invention.

FIG. 3 is a perspective view schematically showing the relationship between the display panel and the electric substrate according to the first embodiment of the present invention.

FIG. 4 is a schematic plan view of a display panel unit according to a second embodiment of the present invention.

FIG. 5 is a schematic sectional view of a display panel unit according to a second embodiment of the present invention.

FIG. 6 is a schematic plan view and a cross-sectional view showing the structure of a basic surface conduction electron-emitting device of the present invention.

FIG. 7 is a schematic cross-sectional view showing the structure of a basic vertical surface conduction electron-emitting device of the present invention.

FIG. 8 is a diagram illustrating an example of a method of manufacturing the surface conduction electron-emitting device of the present invention.

FIG. 9 is a diagram showing an example of a voltage waveform of energization forming according to the present invention.

FIG. 10 is a schematic configuration diagram of a measurement / evaluation apparatus for measuring electron emission characteristics.

FIG. 11 is a diagram showing a configuration example of an electron source having a simple matrix arrangement.

FIG. 12 is a schematic configuration diagram of an image forming apparatus.

FIG. 13 is an explanatory diagram of a fluorescent film.

FIG. 14 is a block diagram showing a schematic configuration of a drive circuit for performing display in accordance with an NTSC television signal and an image forming apparatus having the drive circuit.

FIG. 15 is a diagram showing a configuration example of an electron source having a ladder arrangement.

FIG. 16 is a schematic configuration diagram of an image forming apparatus.

FIG. 17 shows a conventional surface conduction electron-emitting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 display panel unit 2 front plate 3 back plate 4 frame 5 wiring 6 electric circuit board 7 electric components that generate heat 8 electric components 9 heat conducting member 10 display panel 20 image forming unit 30 electron-emitting device unit 60 electric circuit substrate 101 substrate 102, 103 Element Electrode 104 Conductive Thin Film 105 Electron Emission Section 111 Step Forming Section 120 Ammeter for Measuring Element Current If 121 Power Supply for Applying Element Voltage to Electron Emitting Element 122 Ammeter for Measuring Emission Current Ie 123 High-voltage power supply for applying voltage to anode electrode 124 Anode electrode for capturing emission current Ie 125 Vacuum device 126 Exhaust pump 131 Electron source substrate 132 X-direction wiring 133 Y-direction wiring 134 Surface conduction electron-emitting device 135 Connection 141 Rear plate 142 Support frame 143 Glass Plate 144 Fluorescent film 145 Metal back 146 Face plate 147 High voltage terminal 148 Enclosure 151 Black conductive material 152 Phosphor 161 Display panel 162 Scanning circuit 163 Control circuit 164 Shift register 165 Line memory 166 Synchronous signal separation circuit 167 Modulation signal generator, Vx and Va: DC voltage source 170 Electron source substrate 171 Electron emission element 172 Common wiring for wiring electron emission element 180 Grid electrode 181 Hole 182 Outer container terminal made of D _oxm 183 G _n Outer container terminal 201 Substrate 204 conductive thin film 205 electron emission unit

Claims (7)

[Claims] 1. A back plate provided with an electron-emitting device section using an electron-emitting device, a front plate provided with an image forming section facing the electron-emitting section, and a space between the back plate and the front plate. An image forming apparatus having a display panel in which a frame surrounding the electron-emitting device section and the image forming section is hermetically sealed with a sealing material, wherein the back plate has an area projecting from an outer periphery of the frame. The image forming apparatus is characterized in that a heating member for heating the area is provided in contact with the area portion protruding from the outer periphery of the frame. 2. The heating member comprises an electric component that generates heat and a heat conducting member that contacts the electric component, and the heat conducting member is in contact with the protruding portion. The image forming apparatus according to item 1. 3. The image forming apparatus according to claim 1, wherein the heat-generating electric component is mounted on an electric board. 4. The image forming apparatus according to claim 1, wherein the heating member is installed in contact with an outer wall of the frame as well as a portion of the rear plate protruding from the outer periphery of the frame. 5. The heating member comprises an electric component that generates heat and a heat conducting member that contacts the electric component, and the heat conducting member is in contact with the protruding portion and the outer wall of the frame. The image forming apparatus according to claim 4. 6. The image forming apparatus according to claim 1, wherein the electron-emitting device is a surface conduction electron-emitting device. 7. The image forming apparatus according to claim 3, wherein the electric circuit board is a display panel driving electric circuit board.