JPH09230795A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an increase in a cost and to obtain an efficient heat radiation structure by disposing a partition wall between the substrate on the rear surface of a display panel and a driving circuit board. SOLUTION: The substrate 1 and a face plate 6 are arranged to face each other and both thereof are fired and fixed to a supporting frame 7 by frit glass. A metallic plate 10 is installed on the rear surface of the substrate 1 and fins 11 are installed to this metallic plate 10. Further, the driving circuit board 8 for displaying images is installed in a casing 9 by applying electric signals to the display panel consisting of the substrate 1, the face plate 6 and the supporting frame 7. A fan 14 is disposed at the end of this casing 9 and a discharge hole 13 is installed at the surface facing the fan 14. This device is provided with the partition wall 12 between the substrate 1 on the rear surface of the display panel and the driving circuit board 8. Then, the movement of the heat flow from the driving circuit board 8 to the display panel or the backward movement thereof are prevented by this partition wall 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION A display panel including a substrate on which an electron-emitting device is mounted and a face plate on which an image forming member on which an image is formed by irradiation of an electron beam emitted from the electron-emitting device is mounted. The present invention also relates to an image forming apparatus including at least a drive circuit board that generates an electric signal for displaying an image.

[0002]

2. Description of the Related Art Conventionally, there are known two types of electron-emitting devices, which are roughly classified into a thermoelectron-emitting device and a cold cathode electron-emitting device. The cold cathode electron emission device includes a field emission type (hereinafter referred to as “FE type”), a metal / insulating layer / metal type (hereinafter referred to as “MIM type”), a surface conduction type electron emission device, and the like. As an example of the FE type, W. P. Dyke
& W. W. Doran "Field Emissio"
n ", Advance in Electron Phy
sics, 8 89 (1956) or C.I. A. Sp
indt “Physical Properties
of thin-film field emissi
on cathodes with mollybden
ium cones ", J. Appl. Phys., 4
7, 5248 (1976) and the like are known. For the MIM type, C.I. A. Mead, "Opera
Tion of Tunnel-Emission D
devices ", J. Appl. Phys., 32,6.
46 (1961) and the like are known.

As an example of the surface conduction electron-emitting device type,
M. I. Elinson, Radio Eng. Ele
ctron Phys. , 10, 1290 (1965)
Etc. have been disclosed. In the surface conduction electron-emitting device, electrons are emitted by passing a current through a thin film of a small area formed on a substrate in parallel with the film surface. The surface conduction type electron-emitting device may be formed of Sn by Elinson et al.
One using an O ₂ thin film, one using an Au thin film [G. Di
ttmer: Thin Solid Films, 9
317 (1972)], by In ₂ O ₃ / SnO ₂ thin film [M. Hartwell and C.I. G. FIG. Fon
stad: IEEE Trans. ED Conf. ,
519 (1975)], by a carbon thin film [Hiraki Araki et al .: Vacuum, Vol. 26, No. 1, p. 22 (198).
3)] etc. have been reported.

As a typical example of these surface conduction electron-emitting devices, the above-mentioned M. Figure 14 shows the Hartwell device configuration.
Is schematically shown in. In FIG. 1, reference numeral 1 denotes a substrate. Reference numeral 4 denotes a conductive thin film, which is formed of a metal oxide thin film or the like formed by sputtering in an H-shaped pattern, and the electron emission portion 5 is formed by an energization process called energization forming described later.
The element electrode spacing L in the figure is 0.5 mm to 1 mm,
W'is set to 0.1 mm.

Conventionally, in these surface conduction electron-emitting devices, it has been general that the electron-emitting portion 5 is formed in advance by conducting a current called a conductive forming process on the conductive thin film 4 before the electron emission. That is, the energization forming means that a direct current voltage or a very slow rising voltage is applied to both ends of the electroconductive thin film 4 to energize the electroconductive thin film 4 to locally break, deform or alter the electroconductive thin film to a high electrical resistance state. That is, the electron-emitting device portion 5 is formed. In the electron emitting portion 5, a crack is generated in a part of the conductive thin film 4, and electrons are emitted from the vicinity of the crack. The surface conduction electron-emitting device that has been subjected to the energization forming process,
A voltage is applied to the above-mentioned conductive thin film 4 and an electric current is passed through the element so that electrons are emitted from the above-mentioned electron emitting portion 5.

Since the above-mentioned surface conduction electron-emitting device 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, applied research on charged beam sources, display devices, and the like, which make use of this feature, has been conducted. As an example in which a large number of surface-conduction type electron-emitting devices are formed in an array, as will be described later, surface-conduction type electron-emitting devices are arranged in parallel, which is called a ladder arrangement, and both ends of each device are wired (also called common wiring). Then, there is an electron source in which a large number of connected lines are arranged. (For example, JP-A-64-
031332, JP-A-1-283749, 2-2575
52, etc.) In particular, in image forming apparatuses such as display devices, in recent years, flat panel display devices using liquid crystal have become popular in place of CRTs, but since they are not self-luminous, they must have a backlight. There are problems, and it has been desired to develop a self-luminous display device. An example of the self-luminous display device is an image forming device, which is a display device in which a phosphor that emits visible light is combined with electrons emitted from an electron source in which a large number of surface conduction electron-emitting devices are arranged. (Eg, USP 5,066,883)

[0007]

FIG. 15 is a side view and a front view showing the structure of a conventional image forming apparatus (Japanese Patent Laid-Open No. 59-11).
9380). In the figure, reference numeral 1510 is an alphanumeric display, and heat generated from the rear surface of the 1510 is transferred from the heat conducting layer of 1524 to the electronic circuit board 15.
The structure is such that the heat is effectively conducted to the heat dissipation plate 1530 through the through hole provided in 14.

However, providing the through holes in the electronic circuit board leads to an increase in wiring of the wiring on the board and an increase in cost. Further, when the heat generation amount of the display 1510 is larger than that of the electronic circuit board 1514, the temperature of the IC chip is increased, and conversely, when the heat generation amount of the electronic circuit board 1514 is larger than that of the display 1510, the temperature on the electronic circuit board is increased. The heat generation of the IC chip may increase the thermal stress of the display 1510, which may adversely affect the image deterioration and the display damage.

An object of the present invention is to provide an image forming apparatus which suppresses cost increase as much as possible and has an efficient heat dissipation structure regardless of the heat generation amounts of the electronic circuit board and the display.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been made through intensive studies in order to achieve the above object.
That is, the present invention provides: To display an image, a display panel including a substrate on which an electron-emitting device is mounted, a face plate on which an image forming member on which an image is formed by irradiation of an electron beam emitted from the electron-emitting device is mounted 1. An image forming apparatus having at least a drive circuit board for generating an electric signal, characterized in that a partition wall is provided between the board and the drive circuit board on the rear surface of the display panel. 2. The image forming apparatus as described in 1 above, further comprising means for blowing cooling air between the partition wall and the substrate and between the partition wall and the drive circuit board. 3. The image forming apparatus according to 1 or 2 above, wherein a plate material or a film material having a thermal conductivity higher than that of the display panel member is installed on the back surface of the display panel. 5. The image forming apparatus according to any one of 1 to 3 above, wherein an uneven portion made of a material having a higher thermal conductivity than at least the display panel member is provided on the back surface of the display panel or on the plate material / film material. ． 5. The image forming apparatus according to any one of 1 to 4 above, wherein the air passage area of the gap portion increases toward the downstream side in the air blowing direction. 6. The image forming apparatus described in any one of 1 to 5 above, wherein a surface conduction electron-emitting device is used as the electron-emitting device.

By providing a partition between the display panel and the drive circuit board, heat flow from the drive circuit board to the display panel
Or prevent it from moving to the opposite. Therefore, the drive circuit board and the display panel do not adversely affect each other, and each is a system that is thermally and substantially independent of each other. Therefore, the heat dissipation efficiency can be easily increased by using the fan together.

As a result, it is possible to provide an image forming apparatus which suppresses the cost increase as much as possible and has an efficient heat dissipation structure regardless of the amount of heat generated by the electronic circuit board and the display.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an example of an image forming apparatus using the surface conduction electron-emitting device of the present invention. FIG.
In the above, 1 is a substrate on which an electron-emitting device is mounted, and 6
Is a face plate equipped with a phosphor (not shown) on which an image is formed by irradiation of the electron beam emitted from the electron-emitting device. The number of electron-emitting devices is not limited to this embodiment. Substrate 1 and face plate 6
Are opposed to each other, and the substrate and the face plate are baked and fixed to the support frame 7 by frit glass (not shown). Further, a metal plate 10 is installed on the back surface of the substrate 1, and fins 11 are installed on the metal plate 10. A drive circuit board 8 for applying an electric signal to the display panel including the substrate 1, the face plate 6 and the support frame 7 to display an image is installed in the housing 9. A fan 14 is arranged at an end portion (left end portion in the drawing) of the housing 9, and an exhaust hole 13 is provided on a surface facing the fan 14. Further, in the device of the present invention, the partition wall 12 is provided between the substrate 1 on the back surface of the display panel and the drive circuit substrate 8.

The basic structure of the surface conduction electron-emitting device to which the present invention can be applied is roughly classified into a planar type and a vertical type.
There is one. First, the planar surface conduction electron-emitting device will be described. 4A and 4B are schematic diagrams showing the structure of the flat surface conduction electron-emitting device of the present invention, FIG. 4A being a plan view and FIG. 4B being a cross-sectional view. In FIG. 4, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive thin film, and 5 is an electron emitting portion. As the substrate 1, quartz glass, glass having a reduced content of impurities such as Na, soda lime glass, a glass substrate on which SiO ₂ is deposited by a sputtering method, a ceramics substrate such as alumina, or the like can be used.

As the material of the device electrodes 2 and 3, a general conductive material can be used, and Ni, Cr, Au and M are used.
Metals or alloys such as o, W, Pt, Ti, Al, Cu and Pd, and Pd, As, Ag, Au, RuO ₂ , Pd-Ag.
It is possible to select from a printed conductor composed of a metal or a metal oxide such as the above and glass and a transparent conductor such as In ₂ O ₃ —SnO ₂ and a semiconductor material such as polysilicon.
The element electrode interval L, the element electrode length W, the shape of the conductive thin film 4 and the like are designed in consideration of the applied form and the like. The element electrode spacing L is preferably in the range of several thousand angstroms to several hundreds of micrometers, and more preferably in the range of 1 micrometer to 100 micrometers in consideration of the voltage applied between the element electrodes. The device electrode length W is in the range of several micrometers to several hundred micrometers in consideration of the resistance value of the electrodes and the electron emission characteristics. The film thickness d of the device electrodes 2 and 3 is in the range of 100 Å to 1 μm. In addition to the configuration shown in FIG. 4, the conductive thin film 4 and the device electrodes 2 and 3 may be laminated on the substrate 1 in this order.

In order to obtain good electron emission characteristics, it is preferable to use a fine particle film made of fine particles as the conductive thin film 4. The film thickness is appropriately set in consideration of the step coverage to the device electrodes 2 and 3, the resistance value between the device electrodes 2 and 3, and the forming conditions described later, but it is usually in the range of several angstroms to several thousand angstroms. It is preferably in the range of 10 angstroms to 500 angstroms. Its resistance is
Rs is 10 2 to 10 7 Ω. Rs is the resistance R of a thin film having a thickness of t, a width of w and a length of 1, and R = Rs
When the resistivity of the thin film material is ρ, it is represented by Rs = ρ / t. As described below, the forming process will be described by taking the energization process as an example, but the forming process is not limited to this.
Any method may be used as long as it is a method of causing a crack in the film to form a high resistance state.

The material forming the conductive thin film 4 is Pd, P
t, Ru, Ag, Au, Ti, In, Cu, Cr, F
metals such as e, Zn, Sn, Ta, W, Pd, PdO, S
oxides such as nO ₂ , In ₂ O ₃ , PbO, Sb ₂ O ₃ ,
HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ , YB ₄ , G
borides such as dB ₄ , TiC, ZrC, HfC, TaC,
It is appropriately selected from carbides such as SiC and WC, nitrides such as TiN, ZrN, and HfN, semiconductors such as Si and Ge, and carbon.

The fine particle film described here is a film in which a plurality of fine particles are aggregated, and its fine structure has a state in which the fine particles are individually dispersed and arranged, or the fine particles are adjacent to each other or overlap each other (some fine particles are aggregated). However, it also includes the case where an island-shaped structure is formed as a whole). The particle size of the fine particles is in the range of several angstroms to 1 μm, preferably in the range of 10 angstroms to 200 angstroms.

The electron emitting portion 5 is composed of a crack having a high resistance formed in a part of the conductive thin film 4, and depends on the film thickness, film quality, material of the conductive thin film 4 and a method such as energization forming described later. It will be what you did. Inside the electron emitting portion 5,
In some cases, conductive fine particles having a particle size of 1000 angstroms or less are included. The conductive fine particles contain some or all of the elements of the material constituting the conductive thin film 4. The electron emitting portion 5 and the conductive thin film 4 in the vicinity thereof may contain carbon or a carbon compound.

Next, the vertical surface conduction electron-emitting device will be described. FIG. 5 is a schematic view showing an example of the vertical surface conduction electron-emitting device of the present invention.

In FIG. 5, the same parts as those shown in FIG. 4 are designated by the same reference numerals as those shown in FIG.
21 is a step forming part. The substrate 1, the device electrodes 2 and 3, the conductive thin film 4, and the electron emitting portion 5 can be made of the same materials as in the case of the planar surface conduction electron emitting device described above. The step forming portion 21 includes a vacuum deposition method, a printing method,
It can be made of an insulating material such as SiO ₂ formed by a sputtering method or the like. The film thickness of the step forming portion 21 corresponds to the device electrode distance L of the flat surface conduction electron-emitting device described above, and can be set in the range of several thousand angstroms to several tens of micrometers. This film thickness is set in consideration of the manufacturing method of the step forming portion and the voltage applied between the element electrodes, but is preferably in the range of several hundred angstroms to several micrometers.

The conductive thin film 4 is laminated on the device electrodes 2 and 3 after the device electrodes 2 and 3 and the step forming portion 21 are formed. The electron-emitting portion 5 is the step forming portion 21 in FIG.
However, the shape and position are not limited to the above depending on the forming conditions, forming conditions, and the like.

There are various methods for manufacturing the above-mentioned surface conduction electron-emitting device, and one example thereof is schematically shown in FIG. Hereinafter, an example of the manufacturing method will be described with reference to FIGS. 4 and 6. Also in FIG. 6, the same parts as those shown in FIG. 4 are designated by the same reference numerals as those shown in FIG. 1) The substrate 1 is thoroughly washed with a detergent, pure water, an organic solvent and the like, and after the element electrode material is deposited by a vacuum deposition method, a sputtering method or the like, the element electrode 2 is formed on the substrate 1 by using, for example, a photolithography technique. 3 is formed (FIG. 6A). 2) An organometallic solution is applied to the substrate 1 provided with the device electrodes 2 and 3 to form an organometallic thin film. As the organic metal solution, a solution of an organic metal compound containing the metal of the material of the conductive film 4 as a main element can be used. The organometallic thin film is heat-fired and patterned by lift-off, etching, etc. to form the conductive thin film 4 (FIG. 6).
(B)). Here, the method of applying the organic metal solution has been described as an example, but the method of forming the conductive thin film 4 is not limited to this, and a vacuum deposition method, a sputtering method, a chemical vapor deposition method,
It is also possible to use a dispersion coating method, a dipping method, a spinner method, or the like. 3) Subsequently, a forming process is performed. As an example of the forming processing method, a method by an energization processing will be described. When electricity is applied between the device electrodes 2 and 3 by using a power source (not shown), an electron emitting portion 5 having a changed structure is formed at the site of the conductive thin film 4 (FIG. 6C). According to the energization forming, a site having a structural change such as local destruction, deformation or alteration is formed in the conductive thin film 4. This portion becomes the electron emitting portion 5. FIG. 7 shows an example of the voltage waveform of energization forming.

The voltage waveform is preferably a pulse waveform. For this, the method shown in FIG. 7 (a) in which a pulse having a constant pulse peak value is applied continuously, and the method shown in FIG. 7 (b) in which a voltage pulse is applied while increasing the pulse peak value are shown. There is. In FIG. 7A, T1 and T2 are the pulse width and pulse interval of the voltage waveform. Usually, T1 is set in the range of 1 microsecond to 10 milliseconds, and T2 is set in the range of 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. Under such conditions, for example, a voltage is applied for several seconds to several tens minutes. The pulse waveform is not limited to a triangular wave, and a desired waveform such as a rectangular wave can be adopted. T1 and T2 in FIG. 7B can be the same as those shown in FIG. 7A. The peak value of the triangular wave (peak voltage during energization forming) can be increased by, for example, about 0.1 V steps.

The end of the energization forming process can be detected by applying a voltage that does not locally break or deform the conductive thin film 4 during the pulse interval T2 and measure the current. For example, an element current flowing by applying a voltage of about 0.1 V is measured, and a resistance value is obtained. When the resistance value indicates 1 M ohm or more, the energization forming is terminated. 4) It is preferable to perform activation processing on the element that has completed the forming. By performing the activation process, the device current I
f, the emission current Ie changes remarkably.

The activation treatment can be carried out by repeating the application of pulses in the same manner as the energization forming in an atmosphere containing a gas of an organic substance. This atmosphere can be formed by utilizing the organic gas remaining in the atmosphere when the inside of the vacuum container is evacuated by using, for example, an oil diffusion pump or a rotary pump. It can also be obtained by introducing a gas of an appropriate organic substance into a vacuum once sufficiently evacuated by an ion pump or the like. The preferable gas pressure of the organic substance at this time varies depending on the form of application, the shape of the vacuum container, the type of the organic substance, and the like, and is appropriately set depending on the case. Suitable organic substances include alkanes, alkenes, alkyne aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, phenols, carboxylic acids, organic acids such as sulfonic acids, and the like. Specific examples include saturated hydrocarbons represented by CnH _{2n + 2} such as methane, ethane and propane, unsaturated hydrocarbons represented by the composition formula of CnH _2n such as ethylene and propylene, benzene and toluene, Methanol, ethanol, formaldehyde, acetone, methyl ethyl ketone, methylamine, ethylamine, phenol, formic acid, acetic acid, propionic acid and the like can be used. By this treatment, carbon or a carbon compound is deposited on the device from the organic substance existing in the atmosphere, and the device current If and the emission current Ie are significantly changed. To determine the end of the activation process,
The measurement is performed while measuring the device current If and the emission current Ie. The pulse width, pulse interval, pulse crest value, and the like are set as appropriate.

Carbon or carbon compound means HOPG
(Highly Oriented Pyrolytic
 Graphite), PG (Pyrolytic G)
Raphite), GC (Glassy Carbo)
Examples include graphite such as n). (HOPG is
Graphite with a perfect crystal structure, PG has crystal grains
The crystal structure was slightly disordered at about 200 angstroms.
Lafite and GC have crystal grains of about 20 Å
If the crystal structure is more disordered,
You. ), Amorphous carbon (amorphous carbon and
Mixing Morphus Carbon with Microcrystals of Graphite
(Including carbon) and its film thickness is 500 Å
It is preferable that it is less than or equal to Trohm, 300 angstroms
It is more preferable if it is less than or equal to the range. 5) The electron-emitting device obtained through the activation process is stabilized.
Treatment is preferred. This process is performed in a vacuum container.
Partial pressure of organic material is 1 × 10^-8Less than Torr, preferably
1 × 10^-Ten Perform below Torr. Pressure in the vacuum container
Is 10^-6.5-10 ^-7Torr is preferred, especially 1 × 1
0^-8It is preferably Torr or less. Vacuum to evacuate the vacuum container
In the exhaust system, the oil generated from the system affects the element characteristics.
Use the one that does not use oil so as not to give a sound
Is preferred. Specifically, sorption pump, ion
A vacuum exhaust device such as a pump can be used. further
When exhausting the inside of the vacuum container, heat the entire vacuum container.
Molecules adsorbed on the inner wall of the vacuum container or on the electron-emitting device
Is preferably exhausted. Heated at this time
The vacuum evacuation condition in this state is 80 to 200 ° C for 5 hours or more.
However, it is not limited to this condition, but vacuum
Various conditions such as the size and shape of the container and the structure of the electron-emitting device
It changes with. In addition, the partial pressure of the organic substance is measured by mass.
Mainly carbon and hydrogen with mass numbers of 10 to 200 by analyzer
Measure the partial pressure of the organic molecules that are the components, and multiply those partial pressures.
Calculate by calculating.

The atmosphere during driving after the stabilization process is preferably maintained at the atmosphere at the end of the stabilization process, but it is not limited to this, and if the organic substance is sufficiently removed, Even if the degree of vacuum itself is slightly lowered, it is possible to maintain sufficiently stable characteristics. By employing such a vacuum atmosphere, the deposition of new carbon or a carbon compound can be suppressed, and as a result, the device currents If and Ie are stabilized.

Various arrangements of electron-emitting devices can be adopted. As an example, a large number of electron-emitting devices arranged in parallel are connected at both ends, and a large number of rows of electron-emitting devices are arranged (referred to as a row direction), and in a direction orthogonal to this wiring (referred to as a column direction). There is a ladder-like arrangement in which electrons from the electron-emitting device are controlled and driven by a control electrode (also called a grid) arranged above the electron-emitting device. Separately, a plurality of electron-emitting devices are arranged in a matrix in the X and Y directions, and one of electrodes of the plurality of electron-emitting devices arranged in the same row is commonly connected to a wiring in the X direction. For example, the other of the electrodes of the plurality of electron-emitting devices arranged in the same column is commonly connected to the wiring in the Y direction. Such a thing is what is called a simple matrix wiring. First, the simple matrix wiring will be described in detail below.

An electron source substrate obtained by arranging a plurality of electron-emitting devices in a matrix will be described with reference to FIG. 8, reference numeral 71 denotes an electron source substrate, 72 denotes an X-direction wiring, and 73 denotes a Y-direction wiring. 74 is a surface conduction electron-emitting device, and 75 is a connection. Incidentally, the surface conduction electron-emitting device 74 may be either the above-mentioned flat type or vertical type.

The m X-direction wirings 72 are Dx1 and Dx.
2 ,. . . It is made of Dxm and can be made of a conductive metal or the like formed by a vacuum deposition method, a printing method, a sputtering method, or the like. The material, thickness, and width of the wiring are appropriately designed. The Y-direction wiring 73 includes DY1, DY2. . . It is composed of n DYn wirings and is formed similarly to the X-direction wirings 72. These m X-direction wires 72 and n Y-direction wires 7
An interlayer insulating layer (not shown) is provided between
Both are electrically separated (m and n are both positive integers).

The interlayer insulating layer (not shown) is composed of SiO ₂ or the like formed by a vacuum deposition method, a printing method, a sputtering method or the like. For example, it is formed in a desired shape on the entire surface or a part of the substrate 71 on which the X-direction wiring 72 is formed, and in particular, the film thickness, material, and so on to withstand the potential difference at the intersection of the X-direction wiring 72 and the Y-direction wiring 73. The manufacturing method is set. X direction wiring 72 and Y
The directional wirings 73 are respectively drawn out as external terminals.

A pair of electrodes (not shown) constituting the surface conduction electron-emitting device 74 are electrically connected by m X-direction wirings 72, n Y-direction wirings 73, and a connection 75 made of a conductive metal or the like. It is connected. The material forming the wiring 72 and the wiring 73, the material forming the connection 75, and the material forming the pair of element electrodes may have some or all of the same or different constituent elements. These materials are appropriately selected, for example, from the above-described materials for the device electrodes. When the material forming the element electrode is the same as the wiring material, the wiring connected to the element electrode can also be called an element electrode.

A scanning signal applying means (not shown) for applying a scanning signal for selecting a row of the surface conduction electron-emitting devices 74 arranged in the X direction is connected to the X-direction wiring 72.
On the other hand, a modulation signal generating means (not shown) for modulating each column of the surface conduction electron-emitting devices 74 arranged in the Y direction according to an input signal is connected to the Y-direction wiring 73. The driving voltage applied to each electron-emitting device is supplied as a difference voltage between the scanning signal and the modulation signal applied to the device. In the above configuration, individual elements can be selected and driven independently using a simple matrix wiring.
An image forming apparatus configured by using an electron source having such a simple matrix arrangement will be described with reference to FIGS. 9, 10 and 11. 9 is a schematic view showing an example of a display panel of the image forming apparatus, and FIG. 10 is a schematic view of a fluorescent film used in the image forming apparatus of FIG. FIG. 11 is a block diagram showing an example of a drive circuit for displaying according to an NTSC television signal.

In FIG. 9, 71 is an electron source substrate on which a plurality of electron-emitting devices are arranged, 81 is a rear plate to which the electron source substrate 71 is fixed, and 86 is a glass substrate 83 on which a fluorescent film 84, a metal back 85 and the like are formed. It is a face plate. Reference numeral 82 denotes a support frame. A rear plate 81 and a face plate 86 are fixed to the support frame 82 by using frit glass or the like. Reference numeral 88 denotes an envelope, which is fired in the atmosphere or nitrogen in the temperature range of 400 to 500 ° C. for 10 minutes or more and sealed.

Reference numeral 74 corresponds to the electron emitting portion in FIG. 72 and 73 are the X direction wiring and the Y direction connected to the pair of device electrodes of the surface conduction electron-emitting device.

The envelope 88 is composed of the face plate 86, the support frame 82, and the rear plate 81 as described above. Since the rear plate 81 is mainly provided for the purpose of reinforcing the strength of the electron source substrate 71, if the electron source substrate 71 itself has a sufficient strength, the separate rear plate 81 can be unnecessary. That is, the support frame 82 is directly attached to the substrate 71, and the face plate 86, the support frame 82, and the substrate 7 are sealed.
The envelope 88 may be composed of one. On the other hand, by installing a support body (not shown) called a spacer (atmospheric pressure resistant support member) between the face plate 86 and the rear plate 81, the envelope 88 having sufficient strength against atmospheric pressure is configured. You can also do it.

FIG. 10 is a schematic diagram showing a fluorescent film. In the case of monochrome, the fluorescent film 84 can be composed of only the fluorescent material. In the case of a color phosphor film, it can be composed of a black member 91 called a black stripe or a black matrix and a phosphor 92 depending on the arrangement of the phosphors. In the case of color display, the purpose of providing the black stripes and the black matrix is to make the color-separated portion between the phosphors 92 of the three primary color phosphors black so as to make the color mixture inconspicuous and to contrast due to external light reflection. It is to suppress the decrease of. As a material for the black stripe, other than a commonly used material containing graphite as a main component, any material that transmits and reflects less light can be used.

As a method of applying the phosphor to the glass substrate 93, a precipitation method, a printing method or the like can be adopted regardless of monochrome or color. Usually, a metal back 85 is provided on the inner surface side of the fluorescent film 84. The purpose of providing a metal back is
The light emitted from the phosphor toward the inner surface is converted into a face plate 8.
Improve brightness by specular reflection to the 6 side, act as an electrode for applying electron beam acceleration voltage, protect phosphor from damage due to collision of negative ions generated in the envelope, etc. It is. In the metal back, after the phosphor film is produced, the inner surface of the phosphor film is smoothed (usually called “filming”),
Thereafter, it can be manufactured by depositing Al using vacuum evaporation or the like.

The face plate 86 further includes the fluorescent film 8
In order to improve the conductivity of No. 4, a transparent electrode (not shown) may be provided on the outer surface side (the glass substrate 83 side) of the fluorescent film 84.

When performing the above-mentioned sealing, in the case of color, it is necessary to associate each color phosphor with the electron-emitting device.
Sufficient alignment is essential.

The image forming apparatus shown in FIG. 9 is manufactured, for example, as follows. Similarly to the above-described stabilization process, the envelope 88 is appropriately heated and exhausted through an exhaust pipe (not shown) by an exhaust device such as an ion pump or a sorption pump that does not use oil, and is a minus 7th power Torr. After making the atmosphere with a sufficiently small degree of vacuum of an organic substance, it is sealed. In order to maintain a vacuum degree after the envelope 88 is sealed, a getter process may be performed. This is because the getter disposed at a predetermined position (not shown) in the envelope 88 is heated by heating using resistance heating, high-frequency heating, or the like immediately before or after the envelope 88 is sealed. This is a process for forming a deposited film. The getter usually contains Ba or the like as a main component, and maintains the degree of vacuum of, for example, 1 × 10 −5 to 1 × 10 −7 torr due to the adsorption action of the vapor deposition film.

Next, a configuration example of a drive circuit for performing television display based on an NTSC television signal on a display panel constructed by using an electron source having a simple matrix arrangement will be described with reference to FIG. . In FIG. 11, 101 is an image display panel, 102 is a scanning circuit,
Reference numeral 103 is a control circuit, and 104 is a shift register. 1
Reference numeral 05 is a line memory, 106 is a sync signal separation circuit, 10
Reference numeral 7 is a modulation signal generator, and Vx and Va are DC voltage sources.

The display panel 101 has terminals Doxl to D
oxm, terminals Doyl to Doyn, and high-voltage terminal Hv
Connected to an external electric circuit via Terminal Doxl
Scanning for sequentially driving the electron sources provided in the display panel, that is, the surface conduction electron-emitting device groups arranged in a matrix of M rows and N columns matrix by row (N elements). A signal is applied.

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 Dyl to Dyn. The high voltage terminal Hv is supplied with a DC voltage of, for example, 10 K [V] from a DC voltage source Va, which is sufficient to excite the phosphor into an electron beam emitted from the surface conduction electron-emitting device. It is an accelerating voltage for applying energy.

The scanning circuit 102 will be described. The circuit has M switching elements inside (indicated by S1 to Sm in the figure). Each switching element selects either the output voltage of the DC voltage source Vx or 0 [V] (ground level),
It is electrically connected to the terminals Dxl to Dxm of the display panel 101. Each of the switching elements Sl to Sm operates based on the control signal Tscan output from the control circuit 103, and can be configured by combining switching elements such as FETs, for example.

In the case of the present example, the DC voltage source Vx is a driving voltage applied to an element which is not scanned based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting element, and the electron emission threshold value. It is set to output a constant voltage that is less than or equal to the voltage.

The control circuit 103 has a function of matching the operation of each unit so that an appropriate display is performed based on an image signal input from the outside. The control circuit 103 generates control signals Tscan, Tsft, and Tmry for each unit based on the synchronization signal Tsync sent from the synchronization signal separation circuit 106.

The sync signal separation circuit 106 is a circuit for separating a sync signal component and a luminance signal component from an NTSC television signal input from the outside, and uses a general frequency separation (filter) circuit or the like. Can be configured. The synchronizing signal separated by the synchronizing signal separating circuit 106 includes a vertical synchronizing signal and a horizontal synchronizing signal, but is shown here as a Tsync signal for convenience of explanation. The luminance signal component of the image separated from the television signal is referred to as a DATA signal for convenience. This DATA signal is input to the shift register 104.

The shift register 104 is for converting the DATA signal serially input in time series into serial / parallel conversion for each line of the image, and is based on the control signal Tsft sent from the control circuit 103. The control signal Tsft can be said to be a shift lock of the shift register 104. The serial / parallel converted image data for one line (corresponding to driving data for N electron emission elements) is output from the shift register 104 as N parallel signals Idl to Idn.

The line memory 105 is a storage device for storing data for one line of an image for a required time, and stores the contents of Idl to Idn in accordance with the control signal Tmry sent from the control circuit 103. The stored contents are output as I′dl to I′dn and input to the modulation signal generator 107.

The modulation signal generator 107 outputs the image data I ′.
dl to I'dn are signal sources for appropriately driving and modulating each of the surface conduction electron-emitting devices in accordance with each of dl to I'dn, and the output signal thereof is supplied to the surface conduction electron-emitting device in the display panel 101 through terminals Doyl to Doyn. Applied to the emitting element.

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 higher than Vth is applied. For a voltage equal to or higher than the electron emission threshold value, the emission current also changes according to the change in the voltage applied to the device. From this, when a pulse-like voltage is applied to this element, for example, when a voltage lower than the electron emission threshold is applied, electron emission does not occur, but when a voltage higher than the electron emission threshold is applied, the electron beam is emitted. Is output. At this time, the intensity of the output electron beam can be controlled by changing the pulse peak value Vm. In addition, it is possible to control the total amount of charges of the output electron beam by changing the pulse width Pw. Therefore, a voltage modulation method, a pulse width modulation method, or the like can be adopted as a method of modulating the electron-emitting device according to the input signal. When implementing the voltage modulation method, a circuit of a voltage modulation method that generates a voltage pulse of a fixed length and modulates the peak value of the pulse appropriately according to input data is used as the modulation signal generator 107. be able to.

When implementing the pulse width modulation method,
As the modulation signal generator 107, it is possible to use a circuit of a pulse width modulation system that generates a voltage pulse having a constant crest value and appropriately modulates the width of the voltage pulse according to input data.

The shift register 104 and the line memory 10
The digital signal type 5 and the analog signal type 5 can be adopted. This is because the serial / parallel conversion and storage of the image signal may be performed at a predetermined speed.

When the digital signal type is used, it is necessary to convert the output signal DATA of the sync signal separation circuit 106 into a digital signal, which may be provided with an A / D converter at the output portion of 106. In connection with this, the line memory 10
Depending on whether the output signal of 5 is a digital signal or an analog signal,
The circuit used for modulation signal generator 107 is slightly different. That is, in the case of the voltage modulation method using a digital signal, the modulation signal generator 107 is provided with, for example, a D / A
A conversion circuit is used, and an amplification circuit and the like are added as necessary. In the case of the pulse width modulation method, the modulation signal generator 107 includes, for example, a high-speed oscillator, a counter for counting the number of waves output from the oscillator, and a comparator for comparing the output value of the counter with the output value of the memory. (Comparator) is used. If necessary, an amplifier for amplifying the voltage of the pulse width modulated signal output from the comparator to the drive voltage of the surface conduction electron-emitting device can be added.

In the case of the voltage modulation method using an analog signal, the modulation signal generator 107 may be an amplifier circuit using, for example, an operational amplifier, 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 voltage control type oscillation circuit (VCO) can be adopted, and an amplifier for voltage amplification up to the drive voltage of the surface conduction electron-emitting device can be added if necessary.

In the image forming apparatus having such a structure, electrons are emitted by applying a voltage to each electron-emitting device through the terminals outside the container Doxl to Doxm, Doyl to Doyn. A high voltage is applied to the metal back 85 or a transparent electrode (not shown) via the high voltage terminal Hv to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 84 and emit light to form an image.

The configuration of the image forming apparatus described here is an example, and various modifications can be made based on the technical idea of the present invention. For the input signal, the NTSC system has been described, but the input signal is not limited to this, and PAL, SEC
TV with more scanning lines than AM system etc.
Signal (for example, high-quality T including MUSE method)
V) system can also be adopted.

Next, a ladder type electron source and an image forming apparatus will be described with reference to FIGS. 12 and 13.

FIG. 12 is a schematic view showing an example of a ladder-type electron source. In FIG. 12, reference numeral 110 denotes an electron source substrate, and 111 denotes an electron-emitting device. 112, Dx1 to D
x10 is a common wiring for connecting the electron-emitting device 111. The electron-emitting device 111 is provided on the substrate 110 with X
A plurality are arranged in parallel in the direction (this is called an element row). A plurality of the element rows are arranged to constitute an electron source. By applying a drive voltage between the common wires of each element row, each element row can be driven independently. That is, a voltage equal to or higher than the electron emission threshold voltage is applied to the element row where the electron beam is desired to be emitted, and a voltage equal to or lower than the electron emission threshold value is applied to the element row which does not emit the electron beam. The common wirings Dx2 to Dx9 between the element rows are, for example, Dx2 and Dx3.
Can be the same wiring.

FIG. 13 is a schematic view showing an example of a panel structure in an image forming apparatus provided with a ladder-type electron source. 120 is a grid electrode, 121 is an opening for passing electrons, and 122 is Dox1, Dox2 ,. . . Dox
m outside the container. 123 are G1, G2 ,. . . An external terminal 124 made of Gn is an electron source substrate in which the common wiring between the element rows is the same wiring. In FIG. 13, FIG. 9 and FIG.
The same parts as those shown in FIG. 2 are designated by the same reference numerals as those shown in these figures. A major difference between the image forming apparatus shown here and the image forming apparatus having the simple matrix arrangement shown in FIG. 9 is whether or not the grid electrode 120 is provided between the electron source substrate 110 and the face plate 86.

In FIG. 13, a grid electrode 120 is provided between the face plates 86 of the substrate 110. The grid electrode 120 is for modulating the electron beam emitted from the surface conduction electron-emitting device, and is for passing the electron beam through the striped electrodes provided orthogonal to the ladder-shaped element rows. A circular opening 121 is provided for each element.
The shape and installation position of the grid are not limited to those shown in FIG. For example, a large number of passage openings may be provided in the form of a mesh as openings, and a grid may be provided around or near the surface conduction electron-emitting device. The external terminal 122 and the grid external terminal 123 are electrically connected to a control circuit (not shown). In the image forming apparatus of the present embodiment, a modulation signal for one line of an image is simultaneously applied to the grid electrode columns in synchronization with sequentially driving (scanning) the element rows one by one. This makes it possible to control the irradiation of the phosphor with each electron beam and display the image line by line.

The image forming apparatus to which the present invention is applied is, in addition to a display device for a television broadcast, a display device such as a television conference system or a computer, an image forming device as an optical printer constituted by using a photosensitive drum or the like. Can also be used as

[0065]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

Example 1 A known technique, for example, a matrix-arranged electron source substrate having a flat surface conduction electron-emitting device obtained as disclosed in Japanese Patent Laid-Open No. 6-342636 was used to show an embodiment. The image forming apparatus was manufactured as described above. FIG. 1 is a sectional view showing the structure of the manufactured image forming apparatus. The configuration will be described with reference to FIG.

1 is a substrate on which an electron-emitting device is mounted,
Reference numeral 6 denotes a face plate on which a phosphor (not shown) on which an image is formed by irradiation with an electron beam emitted from this electron-emitting device is mounted. The number of electron-emitting devices is not limited to this embodiment.

The substrate 1 and the face plate 6 are arranged so as to face each other, and are baked and fixed to the support frame 7 by frit glass (not shown). The substrate 1, face plate 6 and support frame 7 are made of soda lime glass. Substrate 1
An aluminum metal plate 10 is installed on the back surface of the, and fins 11 are installed on the metal plate. Aluminum metal plate 1
The plate thickness of 0 was 2 mm. The plate thickness is changed depending on the size of the display panel and the amount of heat generation, and is set as appropriate according to the case.
It is preferably about 0.5 mm to several millimeters. In this embodiment, the fin 11 is also made of aluminum and has a length of 5 mm and a width of 2 m.
m, and the height is 2 mm, the pitch between the fins is the width direction,
The length was 10 mm and 20 mm, respectively. The size and pitch of the fins are not limited to the above, and may be set appropriately depending on the heat generation amount of the display panel. The thermal conductivity of the metal plate 10 and the fins 11 (210 W / mk in this example) is that of the soda-lime glass of the display panel member (0.76 in this example).
The larger W / mk), the more effectively heat can be radiated.

Further, the substrate 1, the face plate 6 and the
And give an electric signal to the display panel consisting of the support frame 7.
The drive circuit board 8 for displaying an image is provided in the housing 9.
is set up. At the end of the housing 9 (left end in the figure),
Fan 14 is arranged, and the surface facing the fan 14 is exhausted.
Pores 13 are installed. In this embodiment, the flow rate is 1.3 m
^Three / Min axial flow fan was used. In addition, the display panel
A partition wall 12 is provided between the substrate 1 on the rear side of the module and the drive circuit substrate 8.
Have been killed. The partition wall 12 is a plastic plate having a plate thickness of 2 mm.
And

Here, the heat dissipation mechanism will be briefly described. First, the substrate 1 and the face plate 6 generate heat when an image is displayed. In the display panel, the substrate 1
Since the amount of heat generated by the face plate 6 and the amount of heat generated by the face plate 6 are different from each other, a temperature difference occurs between the substrate 1 and the face plate 6, and the difference in the coefficient of thermal expansion deteriorates the display image and increases the thermal stress. This will damage the display panel. Therefore, the metal plate 10 and the fins 11 made of a metal material having a good thermal conductivity are provided.
By forming and installing the on the back surface of the substrate 1, it is possible to improve heat dissipation efficiency. In order to make the temperature of the display panel uniform, the metal plate 10 is not only on the back surface of the substrate 1 but also on the entire surface other than the image display surface of the display panel on which an insulating film of a glass component is formed by a vacuum deposition method, that is, a support. The structure other than the frame 7 and the image display portion of the face plate 6 may be covered.

Further, since the drive circuit board 8 also generally generates heat, heat is transferred from the drive circuit board 8 to the display panel or vice versa due to the balance of the heat generation amounts of the drive circuit board 8 and the display panel. I will end up. Therefore, in the former case, there is a problem that the image deterioration of the display panel and the increase of thermal stress are caused as described above, and in the latter case, the unstable operation of the IC chip on the drive circuit board is induced.

A partition wall 12 is provided as a means for solving such a problem. That is, the partition wall 12 prevents the heat flow from moving from the drive circuit board 8 to the display panel and vice versa. As a result, the drive circuit board 8 and the display panel can radiate heat as independent systems without affecting each other. As a result, it is possible to provide an image forming apparatus that suppresses cost increase as much as possible and that has an efficient heat dissipation structure regardless of the amount of heat generated by the electronic circuit board and the display.

When the image forming apparatus produced as described above was driven for a long time (tens of hours), the temperature difference between the electron source substrate 1 and the center of the face plate 6 decreased to several degrees, and the image deterioration could not be detected. . Furthermore, the IC on the drive circuit board 8
The operation of the chip was also extremely normal.

The flow rate of the fan 14 is appropriately set according to the heat radiation amount, and is not limited to this embodiment. The type of fan is not limited to the axial fan, but may be a centrifugal fan or a cross fan. Further, the arrangement of the fans is not limited to the present embodiment as long as it can dissipate at least the heat of the metal plate 10 and the fins 11 on the back surface of the substrate 1 and the drive circuit board 8 by blowing air. There is no problem even if the structure is such that the fan 14 blows air on the surface of the face plate 6.

Example 2 An image forming apparatus was manufactured as shown in the embodiment by using a matrix-arranged electron source substrate having a flat surface conduction electron-emitting device obtained in the same manner as in Example 1. FIG. 2 is a sectional view showing the structure of the manufactured image forming apparatus. The configuration will be described with reference to FIG.

In this embodiment, a metal film 15 made of Ag is provided on the back surface of the substrate 1, and fins 11 made of Ag are provided on the metal plate film 15. The thickness of the Ag metal film 15 is several hundreds of μm. The fins 11 are also made of Ag, and in the present embodiment, the length is 5 mm, the width is 0.5 mm, and the height is several hundred μm, and the pitch between the fins is 10 m in each of the width direction and the longitudinal direction.
m, 20 mm. The size and pitch of the fins are not limited to the above, but may be changed according to the amount of heat generation, and may be appropriately set depending on the case. The larger the thermal conductivity of the metal film 15 and the fins 11 (25 W / mk in this example) than that of the soda lime glass of the display panel member (0.76 W / mk in this example), the more effective the heat radiation. it can.

Further, in the present invention, the partition sheet 12 is provided between the substrate 1 on the rear surface of the display panel and the drive circuit substrate 8. The partition sheet 12 is a heat insulating sheet and has a thermal conductivity of 0.06 W / mk. Other configurations in this embodiment are the same as those in the first embodiment, and the same reference numerals are given. The number of electron-emitting devices is not limited to that of the second embodiment shown in FIG.

The heat dissipation mechanism will be briefly described. First, the substrate 1 and the face plate 6 generate heat when an image is displayed. In the display panel, since the heat generation amount of the substrate 1 and the heat generation amount of the face plate 6 are different, a temperature difference occurs between the substrate 1 and the face plate 6, and the difference in the thermal expansion amount causes deterioration of the display image and thermal stress. Increase, and in the worst case, lead to damage of the display panel. Therefore, the metal film 15 and the fin 11 made of a metal material having a good thermal conductivity are formed.
By installing it, it is possible to improve the heat dissipation efficiency. In order to make the temperature of the display panel uniform, the metal film 15 is not only on the back surface of the substrate 1 but also on the entire surface other than the image display surface of the display panel on which an insulating film of a glass component is formed by a vacuum deposition method, that is, a support Frame 7 and face plate 6
The structure other than the image display part may be used.

Further, since the drive circuit board 8 also generally generates heat, heat is transferred from the drive circuit board 8 to the display panel or vice versa due to the balance of the heat generation amounts of the drive circuit board 8 and the display panel. Will end up. Therefore, in the former case, there is a problem that the image deterioration of the display panel and the increase of thermal stress are caused as described above, and in the latter case, the unstable operation of the IC chip on the drive circuit board is induced.

A partition sheet 12 is provided as a means for solving such a problem. That is, the partition sheet 12 prevents the heat flow from moving from the drive circuit board 8 to the display panel or vice versa. As a result, the drive circuit board 8 and the display panel can radiate heat as independent systems without affecting each other. As a result, it is possible to provide an image display device that suppresses cost increase as much as possible and that has an efficient heat dissipation structure regardless of the amount of heat generated by the electronic circuit board and the display.

When the image forming apparatus produced as described above was driven for a long time (several tens of hours), the temperature difference between the center of the electron source substrate 1 and the face plate 6 decreased to several degrees, which is the same as that of the first embodiment. Image deterioration cannot be detected. further,
The operation of the IC chip on the drive circuit board 8 was also extremely normal.

Example 3 An image forming apparatus was manufactured as shown in the embodiment by using a matrix-arranged electron source substrate having a flat surface conduction electron-emitting device obtained in the same manner as in Example 1. FIG. 3 is a sectional view showing the structure of the manufactured image forming apparatus. The configuration will be described with reference to FIG.

In this embodiment, between the substrate 1 on the rear surface of the display panel and the drive circuit substrate 8, a tapered partition wall 12 having a smaller thickness is provided in the downstream direction of the cooling air blown by the fan 14. ing. The partition wall 12 is formed by attaching a heat insulating sheet to a plastic plate.
The spread angle θ of the air flow path in the figure was set to 5 degrees. Depending on the state of the electronic circuit board and the fins, the divergence angle exceeds a certain threshold value and causes a backflow to increase the pressure loss, which lowers the air blowing efficiency of the fan, and is accordingly set according to the configuration of the image forming apparatus. It is a thing. Other configurations in this embodiment are similar to those in the first embodiment, and are designated by the same reference numerals. The number of electron-emitting devices is not limited to that of the third embodiment shown in FIG.

The heat dissipation mechanism will be briefly described. First, the substrate 1 and the face plate 6 generate heat when forming an image. In the display panel, since the heat generation amount of the substrate 1 and the heat generation amount of the face plate 6 are different, a temperature difference occurs between the substrate 1 and the face plate 6, and the difference in the coefficient of thermal expansion causes deterioration of the display image and thermal stress. Increase, and in the worst case, it may damage the display panel. Therefore, by forming and installing the metal film 15 and the fin 11 made of a metal material having a good thermal conductivity, it is possible to improve the heat dissipation efficiency. In order to make the temperature of the display panel uniform,
The metal film 15 is not only on the back surface of the substrate 1 but also on the entire surface other than the image display surface of the display panel on which an insulating film of a glass component is formed by vacuum deposition or the like, that is, the support frame 7 and the face plate 6.
The structure other than the image display part may be used.

Further, since the drive circuit board 8 also generally generates heat, heat is transferred from the drive circuit board 8 to the display panel or vice versa due to the balance of the heat generation amounts of the drive circuit board 8 and the display panel. Will end up. Therefore, in the former case, there is a problem that the image deterioration of the display panel and the increase of thermal stress are caused as described above, and in the latter case, the unstable operation of the IC chip on the drive circuit board is induced.

A partition wall 12 is provided as a means for solving such a problem. That is, the partition wall 12 prevents heat flow from moving from the drive circuit board 8 to the display panel or vice versa. As a result, the drive circuit board 8 and the display panel can radiate heat as independent systems without affecting each other. In addition, as a spreading flow (diffuser) in which the cross-sectional area of the flow passage is gradually increased in the downstream direction, the pressure loss is reduced, the blowing efficiency of the fan is increased, and the heat radiation efficiency is improved. As an effect, the cost increase can be suppressed as much as possible, and an image forming apparatus having an efficient heat dissipation structure can be provided regardless of the heat generation amount of the electronic circuit board and the display. When the image forming apparatus produced as described above was driven for a long time (several tens of hours), the temperature difference between the center of the electron source substrate 1 and the face plate 6 was reduced to several degrees, which is about the same as or lower than that in Example 1, and image deterioration was caused. It could not be detected. Furthermore, the operation of the IC chip on the drive circuit board 8 was also extremely normal.

[0087]

The partition walls prevent heat flow from moving from the drive circuit board to the display panel or vice versa, and the drive circuit board and the display panel do not adversely affect each other, and further, they are substantially independent systems. Therefore, it is possible to provide an image forming apparatus having a heat dissipation structure that suppresses cost increase as much as possible and that has an efficient heat dissipation structure regardless of the amount of heat generated by the electronic circuit board and the display.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating an example of an image forming apparatus of the present invention.

FIG. 2 is a cross-sectional view showing another example of the image forming apparatus of the present invention.

FIG. 3 is a sectional view showing another example of the image forming apparatus of the present invention.

FIG. 4 is a schematic plan view and a cross-sectional view showing a configuration of a planar surface conduction electron-emitting device applied to the present invention.

FIG. 5 is a schematic diagram of a vertical surface conduction electron-emitting device applied to the present invention.

FIG. 6 is a schematic view showing a method of manufacturing a surface conduction electron-emitting device applied to the present invention.

FIG. 7 is a schematic diagram showing an example of a voltage waveform in an energization forming process that can be adopted for manufacturing the surface conduction electron-emitting device applied to the present invention.

FIG. 8 is a schematic view showing an example of a matrix arrangement type electron source substrate applied to the present invention.

FIG. 9 is a schematic view showing an example of a display panel of the image forming apparatus of the present invention.

FIG. 10 is a schematic view showing an example of a fluorescent film.

FIG. 11 is a block diagram showing an example of a drive circuit for performing display according to an NTSC television signal on the image forming apparatus.

FIG. 12 is a schematic view showing an example of a ladder type arrangement type electron source substrate applied to the present invention.

FIG. 13 is a schematic diagram illustrating an example of a display panel of the image forming apparatus of the present invention.

FIG. 14 is a schematic view of a conventional surface conduction electron-emitting device.

FIG. 15 is a diagram showing an example of heat dissipation of a conventional image forming apparatus.

[Explanation of symbols]

1: Substrate 2, 3: Element electrode 4: Conductive thin film 5: Electron emission part 6: Face plate 7: Support frame 8: Drive circuit board 9: Housing 10: Metal plate 11: Fin 12: Partition wall 13: Exhaust hole 14: Fan 15: Metal Film 21: Step Forming Part 22: Partition Sheet 32: Tapered Partition 71: Electron Source Substrate 72: X Direction Wiring 73: Y Direction Wiring 74: Surface Conduction Electron Emitting Element 75: Wiring 81: Rear Plate 82: Support frame 83: Glass substrate 84: Fluorescent film 85: Metal back 86: Face plate 87: High voltage terminal 88: Envelope 91: Black member 92: Phosphor 101: Display panel 102: Scanning circuit 103: Control circuit 104: shift register 105: line memory 106: synchronization signal separation circuit 107: modulation signal generator Vx, Va: DC voltage source 110: electron source group Plate 111: Electron-emitting device 112: Common wiring of electron-emitting device consisting of Dx1 to Dx10 120: Grid electrode 121: Open hole for passing electrons 122: Dox1, Dox2 ,. . . Doxm outer terminal 123: G1, G2 ,. . . Outer terminal of GN

Claims (6)

[Claims] 1. A display panel comprising a substrate on which an electron-emitting device is mounted and a face plate on which an image forming member on which an image is formed by irradiation of an electron beam emitted from the electron-emitting device is mounted. An image forming apparatus having at least a drive circuit board for generating an electric signal for displaying an image, wherein a partition is provided between the board on the rear surface of the display panel and the drive circuit board. 2. The image forming apparatus according to claim 1, further comprising means for blowing cooling air between the partition wall and the substrate and between the partition wall and the drive circuit board. 3. The image forming apparatus according to claim 1, wherein a plate material or a film material having a higher thermal conductivity than at least the display panel member is installed on the back surface of the display panel. 4. An uneven portion made of a material having a thermal conductivity higher than that of at least the display panel member is provided on the back surface of the display panel or on the plate material / film material. The image forming apparatus described. 5. The image forming apparatus according to claim 1, wherein the air passage area of the gap portion increases toward the downstream side in the air blowing direction. 6. The image forming apparatus according to claim 1, wherein a surface conduction electron-emitting device is used as the electron-emitting device.