JP3347569B2 - Flat plate type image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is by applying the electron source flat
It relates to a plate type 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. A. S
pindt, "Physical Properties"
s of thin-film field emis
sion cathodes with mollybd
enium ", J.Appl.Phys., 47 52
48 (1976).

As an example of the MIM type, C.I. A. Mea
d, "The tunnel-emission am
plier ", J. Appl. Phys., 32 .
646 (1961).

Examples of the surface conduction electron-emitting device type include:
M. I. Elinson, Radio Eng. Ele
ctron Phys. , 10 (1965).
The surface conduction electron-emitting device utilizes the phenomenon that electron emission occurs when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. As the surface conduction electron-emitting device, SnO by Elinson et al.
₂ Using a thin film, using an Au thin film [G. Dit
tmer: “Thin Solid Films”, 9
317 (1972)], an In ₂ O ₃ / SnO ₂ thin film [M. Hartwell and C.M. G. FIG. F
onstad: "IEEE Trans. ED Con
f. , 519 (1975)], using a carbon thin film [Hisashi 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 above-mentioned M.S. FIG. 14 shows a device configuration of the Hartwell. 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 emitting portion 5 is formed by an energization process called energization forming described later. In the drawing, the element electrode interval L is 0.5 to 1 mm, and W is
It is set at 0.1 mm. Since the position and shape of the electron-emitting portion 5 are unknown, they are shown as schematic diagrams.

Conventionally, in these surface conduction electron-emitting devices, before the electron emission, the conductive thin film 4 is generally subjected to an energization process called energization forming to form an electron emission portion 5. . That is, the energization forming is to apply a DC voltage or a very slowly increasing voltage, for example, about 1 V / min, to both ends of the conductive thin film 4 and to energize the conductive thin film 4 to locally destroy, deform or alter the conductive thin film. To form the electron-emitting portion 5 in a high resistance state. 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. In the surface conduction type electron-emitting device subjected to the energization forming process, a voltage is applied to the conductive thin film 4 and a current is caused to flow through the device to cause the electron-emitting portion 5 to emit electrons.

The above-mentioned surface conduction type electron-emitting device has an advantage that a large number of devices can be arranged and formed over a large area because of its simple structure and easy manufacture. Therefore, various applications that can take advantage of this feature are being studied. For example, a display device such as a charged beam source and an image display device can be used.

FIG. 15 is an example showing a fixing method and a fixing device of a display panel in a conventional flat plate type image forming apparatus. In FIG. 1, reference numeral 6 denotes a display panel including a substrate 7 on which an electron-emitting device group is mounted, a face plate 8 on which an image forming member is mounted, and a support frame 9. Reference numeral 19 denotes a panel housing including the display panel 6 and the drive circuit board 10. Reference numeral 12 denotes a support device for fixing the display panel to a panel housing. The display panel is fixedly supported by the support device 12 on the surface of the substrate 7 opposite to the surface facing the face plate 8 with a double-sided tape 20. ing.

FIG. 16 shows another example of a fixing method and a fixing device for a display panel in a conventional flat panel type image forming apparatus. In FIG. 1, reference numeral 6 denotes a display panel including a substrate 7 on which an electron-emitting device group is mounted and a face plate 8 on which a support frame-integrated image forming member is mounted. Reference numeral 19 denotes a panel housing including the display panel 6 and the drive circuit board 10. Reference numeral 12 denotes a support device for fixing the display panel to a panel housing, and the display panel is supported and fixed by sandwiching four corners of the substrate between elastic members 13 provided on the support device.

However, in the image forming apparatus having the fixing method and the fixing device described above, the fixing becomes unstable due to the aging of the double-sided tape. In addition, since the rigidity of the display panel decreases as the display panel becomes thinner, the method of fixing and supporting the four corners of the substrate causes large deformation (warpage of the display panel) due to thermal stress and stress at atmospheric pressure during driving. As a result, a vacuum leak or a worst case breakage may occur from an extraction electrode portion (not shown).

[0011]

OBJECTS OF THE INVENTION It is an object of this invention is to eliminate the drawbacks of the above conventional method, allowing the warp of the display panel, without applying extra load to the display panel, safely and stably fixed To provide a flat-plate type image forming apparatus capable of performing such operations.

[0012]

The flat image forming apparatus of the present invention is as follows. 1. A substrate (A) on which an electron-emitting device group is mounted and an image forming member on which an image is formed by irradiation of an electron beam emitted from the electron-emitting device group are mounted, and are arranged to face the substrate (A). A flat panel image forming apparatus in which a display panel including a face plate (B) and a support frame (C) between the substrate (A) and the face plate (B) is fixed in a housing, the face plate ( B) of the face plate (B) on the surface opposite to the surface facing the substrate (A).
First supporting means contacting each of a plurality of locations on a peripheral portion corresponding to a portion where the first supporting means and the supporting frame (C) are in contact with each other; and a first supporting means fitted to the display panel and coupled to the plurality of first supporting means. 2
Has a support means, places where the respective and the peripheral portion of the plurality of first support means are in contact is in the portion other than the central portion and the central portion of each side constituting a peripheral edge portion, A flat plate type image forming apparatus, wherein the elastic force of the first support means contacting a part other than the central part is smaller than the elastic force of the first support means contacting the central part. 2. A substrate (A) on which an electron-emitting device group is mounted and an image forming member on which an image is formed by irradiation of an electron beam emitted from the electron-emitting device group, and a face arranged to face the substrate (A) A flat panel image forming apparatus comprising a display panel including a plate (B) and a support frame (C) between a substrate (A) and a face plate (B) fixed in a housing . A first supporting means forming a front frame having a window, a second supporting means fitted in the display panel and coupled to the first supporting means , disposed in the housing ,
Plate (B) on the side opposite to the surface facing the substrate (A).
Is provided on the back of the front frame so that it contacts
And a plurality of elastic projections.
Is where the face contacts the face plate (B).
Corresponds to the area where the plate (B) and the support frame (C) are in contact
The peripheral portion of the face plate (B)
The portion where the portion contacts the peripheral portion is located at the central portion and the portions other than the central portion of each side constituting the peripheral portion, and contacts the portion other than the central portion than the elastic force of the protrusion contacting the central portion A flat plate type image forming apparatus characterized in that the elastic force of the projection is small. 3. The second support means has a back plate, and the back plate has
3. The flat-plate type image forming apparatus according to the above item 2, having elastic projections at a plurality of peripheral portions corresponding to portions where the substrate (A) and the support frame (C) are in contact with each other. 4. The projections of the second support means are located at the center of each side constituting the peripheral portion of the back plate and at a portion other than the center, and the projections of the second support means at this center are provided. 4. The flat plate type image forming apparatus according to the above item 3, wherein the elastic force of the projection of the second support means located at a portion other than the central portion is smaller than the elastic force of the projection. 5. 5. The flat panel image forming apparatus according to the above 3 or 4, wherein the back plate is a substrate on which a drive circuit for driving the electron-emitting device group is mounted. 6. The flat panel image forming apparatus according to any one of the above 1 to 5, wherein a surface conduction electron-emitting device is used as the electron-emitting device.

[0013] Flat plate type image forming constructed according to the present invention
In the device, the display panel can be allowed to bend, and secure and stable fixing can be performed without applying an extra load to the display panel.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will now be described with reference to the drawings. FIG. 1 shows a method and an apparatus for fixing a display panel in an image forming apparatus according to an embodiment of the present invention. In the drawing, reference numeral 6 denotes a substrate 7 on which an electron-emitting device group (not shown) is mounted, and a face plate 8 on which an image forming member (not shown) on which an image is formed by an electron beam emitted from the electron-emitting device group, The display panel includes a support frame 9 provided between the substrate 7 and the face plate 8. Reference numeral 14 denotes a reinforcing member / support device for supporting the entire surface of the substrate 7 and constitutes second supporting means.
The first support means is constituted by a support device on the face plate side provided with elasticity by a leaf spring, and presses a portion (hatched portion in the figure) corresponding to a portion of the face plate which comes into contact with the support frame. The reinforcing member / supporting device 14 and the supporting devices 15a to 15c are fixed with screws or the like. Reference numeral 19 denotes a panel housing that includes the display panel 6, the support members 14, 15a to c, and the drive circuit board 10 that emits an image display signal. Each member is fixed to the panel housing 19 with screws.

As the above-mentioned electron-emitting device group, a surface-conduction type electron-emitting device group which has a simple structure and is easy to manufacture is preferable. There are basically two types of surface conduction electron-emitting devices: a flat surface conduction electron-emitting device and a vertical surface conduction electron-emitting device. FIGS. 3A and 3B are schematic views showing the configuration of a basic surface conduction electron-emitting device, and FIGS. 3A and 3B are a plan view and a sectional view, respectively. In FIG. 3, 1 is a substrate,
Reference numerals 2 and 3 denote device electrodes, 4 denotes a conductive thin film, and 5 denotes an electron emitting portion. As the substrate 1, quartz glass, glass having a low impurity content such as Na, blue plate glass, a glass substrate having SiO ₂ formed on its surface, or a ceramic substrate such as alumina is used. As a material for the device electrodes 2 and 3, a general conductor is used. For example, Ni, Cr, Au, Mo, W, P
metals or alloys such as t, Ti, Al, Cu, Pd and P
a printed conductor composed of a metal such as d, Ag, Au, RuO ₂ , Pd—Ag or a metal oxide and glass, In ₂ O
It is appropriately selected from a transparent conductor such as _3- SnO ₂ and a semiconductor material such as polysilicon.

The element electrode interval L is preferably in the range of several hundred angstroms to several hundred micrometers. Further, it is desirable that the voltage applied between the device electrodes is low, and it is necessary to produce the material with good reproducibility. Therefore, the preferable device electrode interval is in the range of several micrometers to several tens of micrometers. The device electrode length W is in the range of several micrometers to several hundred micrometers according to the resistance and electron emission characteristics of the electrode, and the film thickness of the device electrodes 2 and 3 is in the range of several hundred angstroms to several micrometers. Is preferred.

Instead of the configuration shown in FIG. 3, a configuration may be adopted in which the conductive thin film 4 and the electrodes of the device electrodes 2 and 3 are sequentially formed on the substrate 1.

The conductive thin film 4 is particularly preferably a fine particle film composed of fine particles in order to obtain good electron emission characteristics. The thickness of the fine film is step coverage to the device electrodes 2 and 3, and resistance between the device electrodes 2 and 3. It is set as appropriate depending on the value and the energizing forming conditions to be described later, but is preferably from several angstroms to several thousand angstroms, particularly preferably from 10 angstroms to 500 angstroms. The sheet resistance is 10 3 to 10 7 ohms / square.

The material constituting the conductive thin film 4 is Pd, P
t, Ru, Ag, Au, Ti, In, Cu, Cr, F
e, metal such as Zn, Sn, Ta, W, Pb, 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,
Carbides such as SiC and WC; nitrides such as TiN, ZrN and HfN; 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, and has a fine structure not only in a state where the fine particles are individually dispersed and arranged, but also when the fine particles are adjacent to each other.
Alternatively, it refers to a film in an overlapped state (including an island shape), and the particle size of the fine particles is in the range of several angstroms to several thousand angstroms, and preferably in the range of 10 to 200 angstroms.

The electron emitting portion 5 is a high-resistance crack formed in a part of the conductive thin film 4, and is formed by energization forming or the like. The crack may have conductive fine particles having a particle size of several Angstroms to several hundred Angstroms. The conductive fine particles contain at least some of the elements constituting the conductive thin film 4. Further, the electron emitting portion 5 and the conductive thin film 4 in the vicinity thereof may include carbon and a carbon compound.

FIG. 4 is a schematic sectional view showing the basic structure of a vertical surface conduction electron-emitting device. 4, the same members as those in FIG. 3 are denoted by the same reference numerals. 2
1 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 material as that of the above-mentioned flat surface-conduction type electron-emitting device, and the step forming portion 21 is made of an insulating material. The film thickness of the step forming portion 21 corresponds to the device electrode interval L of the flat surface conduction electron-emitting device described above. The spacing ranges from hundreds of angstroms to tens of micrometers. The distance can be controlled by the manufacturing method of the step forming portion and the voltage applied between the device electrodes, but is preferably in the range of several hundred angstroms to several micrometers. The conductive thin film 4 is formed on the device electrodes 2 and 3 because the conductive thin film 4 is formed after the device electrodes 2 and 3 and the step forming portion 21 are formed. FIG.
Although the electron-emitting portion 5 is shown as being formed linearly on the step forming portion 21, the shape and position are not limited to this depending on the forming conditions, energizing forming conditions, and the like.

Various methods are conceivable as a method of manufacturing the above-mentioned surface conduction electron-emitting device. One example is shown in FIG. Hereinafter, a method for manufacturing the electron source substrate will be described with reference to FIGS. In FIG. 5, the same members as those in FIG. 3 are denoted by the same reference numerals. 1) After sufficiently washing the substrate with a detergent, pure water and an organic solvent, an element electrode material is deposited by a vacuum deposition method, a sputtering method, or the like. Thereafter, device electrodes 2 and 3 are formed on the substrate by photolithography (FIG. 5A). 2) An organometallic solution is applied to the substrate 1 on which the device electrodes 2 and 3 are provided and left to form an organometallic thin film.
The organometallic solution here is a solution of an organometallic compound containing the above-mentioned metal forming the conductive film 4 as a main element. Thereafter, the organic metal thin film is heated and baked, and is patterned by lift-off, etching, or the like to form a conductive thin film 4 (FIG. 5B). Here, the formation of the conductive thin film has been described by the application method of the organometallic solution. However, the invention is not limited thereto, but the vacuum evaporation method, the sputtering method, the chemical vapor deposition method, the dispersion coating method, the dipping method, the spinner method. It can also be formed by the above method. 3) Subsequently, an energization process called energization forming is performed. In the energization forming, an electric current is applied between the element electrodes 2 and 3 from a power source (not shown) to locally destroy, deform or alter the conductive thin film 4, thereby forming a portion having a changed structure. The site where the structure is locally changed is called an electron emitting portion 5 (FIG. 5C).

FIG. 6 shows an example of the voltage waveform of the energization forming. The voltage waveform is particularly preferably a pulse waveform. When a voltage pulse having a constant pulse peak value is continuously applied (see FIG. 6).
(A)) and a case where a voltage pulse is applied while increasing the pulse peak value (FIG. 6 (b)). First, the case where the pulse crest value is a constant voltage (FIG. 6A) will be described.

In FIG. 6A, T1 and T2 are the pulse width and pulse interval of the voltage waveform, T1 is 1 microsecond to 10 milliseconds, T2 is 10 microseconds to 100 milliseconds, and the peak value of the triangular wave ( The peak voltage at the time of energization forming is appropriately selected according to the form of the surface conduction electron-emitting device, and a voltage of several seconds to several tens minutes is applied under an appropriate vacuum degree, for example, in a vacuum atmosphere of about 10 −5 torr. Apply. The voltage 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. FIG.
T1 and T2 in (b) are the same as in FIG. 6 (a), and the peak value of the triangular wave (peak voltage at the time of energization forming) is increased, for example, in steps of about 0.1 V and applied under an appropriate vacuum atmosphere. .

In the energization forming process, the element current is measured at a voltage that does not locally destroy or deform the conductive thin film 4 during the pulse interval T2, for example, a voltage of about 0.1 V.
A resistance value is obtained, and when, for example, a resistance of 1 M ohm or more is indicated, the energization forming is terminated. 4) It is desirable to perform a process referred to as an activation process on the device after the energization forming. The activation process is, for example, a process of repeatedly applying a voltage pulse having a constant pulse peak value at a degree of vacuum of about 10 −4 to 10 −5 torr, as in the energization forming. Is a process of depositing carbon and a carbon compound resulting from the organic substance existing on the conductive thin film to significantly change the device current If and the emission current Ie. The activation process ends while measuring the device current If and the emission current Ie, for example, when the emission current Ie is saturated. Further, it is preferable that the applied voltage pulse be performed at an operation drive voltage. Here, the carbon and the carbon compound are graphite (refer to both monocrystalline and polycrystalline) and amorphous carbon (refer to a mixture of amorphous carbon and polycrystalline graphite), and the film thickness is preferably 500 Å or less, More preferably, it is 300 Å or less. 5) It is preferable to operate and drive the electron-emitting device thus prepared in an atmosphere having a degree of vacuum higher than the degree of vacuum in the energization forming step and the activation step. Further, it is desirable to drive the device after heating at 80 ° C. to 150 ° C. in an atmosphere with a higher degree of vacuum. Here, the degree of vacuum higher than the degree of vacuum in the energization forming step and the activation treatment is, for example, a degree of vacuum of about 10 −6 or more, more preferably an ultra-high vacuum system, and a new carbon and carbon compound. Is a vacuum degree that hardly deposits on the conductive thin film. This makes it possible to stabilize the element current If and the emission current Ie.

FIG. 7 is a schematic configuration diagram of a measurement evaluation apparatus for measuring the electron emission characteristics of the device having the configuration shown in FIG. 7, the same reference numerals as those in FIG. 3 denote the same components. Reference numeral 71 denotes a power supply for applying a device voltage Vf to the electron-emitting device; 70, an ammeter for measuring a device current If flowing through the conductive thin film 4 between the device electrodes 2 and 3;
Is an anode electrode for capturing an emission current Ie emitted from the electron emission portion of the device, 73 is a high voltage power supply for applying a voltage to the anode electrode 74, and 72 is an emission current emitted from the electron emission portion 5 of the device. An ammeter for measuring Ie, 75 is a vacuum device, and 76 is an exhaust pump.

Next, the image forming apparatus of the present invention will be described. An electron source substrate used in an image forming apparatus is formed by arranging a plurality of surface conduction electron-emitting devices on a substrate. In the method of arranging the surface conduction electron-emitting devices, the surface conduction electron-emitting devices are arranged in parallel, and both ends of the individual devices are connected by wiring in a ladder-type arrangement (hereinafter referred to as a ladder-type arrangement electron source substrate), A simple matrix arrangement in which an X-direction wiring and a Y-direction wiring are respectively connected to a pair of device electrodes of a surface conduction electron-emitting device (hereinafter, referred to as a matrix-type arrangement electron source substrate) can be given. 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 the electron-emitting devices.

Hereinafter, the configuration of an electron source configured based on this principle will be described with reference to FIG. 81 is an electron source substrate, 82 is an X-direction wiring, 83 is a Y-direction wiring, 84 is a surface conduction electron-emitting device, and 85 is a connection. The surface conduction electron-emitting device 84 may be of the above-mentioned flat type or vertical type. In the figure, the substrate used as the electron source substrate 81 is the above-mentioned glass substrate or the like, and the shape is appropriately set according to the application. The m X-direction wirings 82 are Dx1,
Dx2,... Dxm, and the Y-direction wiring 83 is Dy
1, Dy2,... Dyn. The material, the film thickness, and the wiring width are appropriately set so that a substantially uniform voltage is supplied to a large number of surface conduction elements. The m X-directional wirings 82 and the n Y-directional wirings 83 are electrically separated by an interlayer insulating layer (not shown) to form a matrix wiring (m and n are both positive integers). An interlayer insulating layer (not shown) is formed in a desired region on the entire surface or a part of the substrate 81 on which the X-directional wiring 82 is formed. The X-direction wiring 82 and the Y-direction wiring 83 are respectively drawn out as external terminals. Further, the device electrode (not shown) of the surface conduction type emission device 84 is m
X direction wirings 82, n Y direction wirings 83, and connection 85
Are electrically connected by The surface conduction electron-emitting device may be formed on either the substrate or the interlayer insulating layer (not shown).

Although not described in detail later, the X-direction wiring 82 is not shown for applying a scanning signal for scanning a row of the surface conduction electron-emitting devices 84 arranged in the X direction in accordance with an input signal. It is electrically connected to the scanning signal generating means. On the other hand, the Y-direction wiring 83 includes a modulation signal generating means (not shown) for applying a modulation signal for modulating each of the rows of the surface conduction electron-emitting devices 84 arranged in the Y-direction according to an input signal. It is electrically connected. The drive voltage applied to each element of the surface conduction electron-emitting device is supplied as a difference voltage between a scanning signal and a modulation signal applied to the element.

In the above configuration, individual elements can be selected and driven independently only by simple matrix wiring.

Next, an image forming apparatus using the matrix-type arranged electron source substrate prepared as described above will be described with reference to FIGS. 9, 10 and 11. FIG. 9 is a basic configuration diagram of an image forming apparatus, FIG. 10 is a block diagram of a fluorescent film, and FIG. 11 is a block diagram of a drive circuit for displaying according to an NTSC television signal. Represents a device. 9, reference numeral 81 denotes an electron source substrate on which an electron-emitting device is formed, 91 denotes a rear plate to which the electron source substrate 81 is fixed, and 96 denotes a glass substrate 93 having a fluorescent film 94 and a metal back 95 formed on the inner surface thereof. A face plate, 92 is a support frame, and 91 is a rear plate. These members constitute a display panel 98. Reference numeral 84 corresponds to the electron-emitting portion in FIG. Reference numerals 82 and 83 denote an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the surface conduction electron-emitting device.

The display panel 98 includes the face plate 96, the support frame 92, and the rear plate 91 as described above. However, since the rear plate 91 is provided mainly for reinforcing the strength of the electron source substrate 81, If the source substrate 81 itself has sufficient strength, a separate rear plate 91 is unnecessary, and a support frame 92 is provided directly on the electron source substrate 81, and the face plate 96, the support frame 92, and the electron source substrate 81 are used to form a display panel. 98 may be configured.

In FIG. 10, reference numeral 102 denotes a phosphor. Phosphor 1
Numeral 02 consists of only a phosphor in the case of monochrome, but in the case of a color phosphor film, it is composed of a black conductive material 101 called a black stripe (a) or a black matrix (b) and a phosphor 102 depending on the arrangement of the phosphor. Is done. The purpose of providing the black stripes and the black matrix is to make the color separation inconspicuous by making the painted portions between the respective phosphors 102 of the necessary three primary color phosphors black in the case of color display, Is to suppress a decrease in contrast due to reflection of external light in the above. The material for the black stripe is not limited to a material mainly containing graphite, which is generally used, and may be any material having conductivity and low transmission and reflection of light.

As a method of applying a phosphor to the glass substrate 93 in FIG. 9, a precipitation method or a printing method is used regardless of monochrome or color. A metal back 95 is usually provided on the inner surface side of the fluorescent film 94. The purpose of the metal back is to improve the brightness by mirror-reflecting the light emitted from the phosphor toward the inner surface side to the face plate 96 side, to act as an electrode for applying an electron beam accelerating voltage, and to display panel. Protection of the phosphor from damage due to the collision of negative ions generated inside. The metal back can be produced by performing a smoothing process (usually called filming) on the inner surface of the phosphor film after producing the phosphor film, and then depositing Al by vacuum deposition or the like. The face plate 96 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 94 to further enhance the conductivity of the fluorescent film 94.

The display panel 98 passes through an exhaust pipe (not shown).
The degree of vacuum is set to about 10 ⁻⁷ torr, and sealing is performed. In some cases, getter processing is performed to maintain the degree of vacuum of the display panel 98 after sealing. This is to heat a getter disposed at a predetermined position (not shown) in the display panel 98 by a heating method such as resistance heating or high-frequency heating immediately before or after the sealing of the display panel 98, and remove the deposited film. This is the process of forming. The getter is usually composed mainly of Ba or the like.
The degree of vacuum is maintained at 10 ^-5 torr or 1 × 10 ^-7 torr. Steps after forming the surface conduction electron-emitting device are appropriately set.

Next, a schematic structure of a driving circuit for performing a television display based on an NTSC television signal in an image forming apparatus constituted by using a matrix type electron source substrate will be described with reference to a block diagram of FIG. explain. 111 is the display panel, 112 is a scanning circuit, 113
Is a control circuit, 114 is a shift register, 115 is a line memory, 116 is a synchronization signal separation circuit, 117 is a modulation signal generator, and Vx and Va are DC voltage sources.

The function of each part will be described below. First, the display panel 111 is connected to the terminals Dox1 to Doxm and the terminal Dx.
It is connected to an external electric circuit via oy1 to Doyn and the high voltage terminal Hv. Of these terminals, the terminals Dox1 to Doxm sequentially drive electron sources provided in the image forming apparatus, that is, a group of surface conduction electron-emitting devices arranged in a matrix of M rows and N columns in a row (N elements). A scanning signal for performing the scanning is applied.

On the other hand, to the terminals Dy1 to Dyn, a modulation signal for controlling the output electron beam of each element of one row of the surface conduction electron-emitting devices selected by the scanning signal is applied. Further, a DC voltage of, for example, 10 [kV] is supplied to the high voltage terminal Hv from the DC voltage source Va, which is enough to excite the phosphor into an electron beam output from the surface conduction electron-emitting device. It is an accelerating voltage for applying energy.

Next, the scanning circuit 112 will be described. This circuit has M switching elements inside (in the figure, S1 to Sm are schematically shown), and each switching element is provided with an output voltage of a DC voltage source Vx or 0V.
[V] (ground level) is selected and electrically connected to the terminals Dx1 to Dxm of the display panel 111. Each of the switching elements S1 to Sm operates based on the control signal Tscan output from the control circuit 113, but can be actually configured by combining switching elements such as FETs. Note that the DC voltage source Vx is such that the drive voltage applied to an element that is not scanned based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting element is equal to or lower than the electron emission threshold voltage. It is set to output a constant voltage.

The control circuit 113 has a function of matching the operation of each part so that 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 116 described below, Tscan, Tsft, and Tm
ry control signals are generated.

The synchronizing signal separating circuit 116 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input from the outside, and can be formed by using a frequency separating (filter) circuit. The synchronization signal separated by the synchronization signal separation circuit 116 is composed of a vertical synchronization signal and a horizontal synchronization signal, as is well known, but is shown here as a Tsync signal for convenience of explanation. On the other hand, the luminance signal component of the image separated from the television signal is referred to as a DATA signal for convenience, and the signal is input to the shift register 114.

The shift register 114 performs serial / parallel conversion of the DATA signal input serially in time series for each line of an image, and operates based on a control signal Tsft sent from the control circuit 113. . (That is, the control signal Tsft is
It may be rephrased as 14 shift clocks. The data for one line of the serial / parallel-converted image (corresponding to drive data for N electron-emitting devices) is Id
It is output from the shift register 114 as N parallel signals of 1 to Idn.

The line memory 115 is a storage device for storing data of one line of an image for a required time only, and stores the contents of Id1 to Idn as appropriate according to a control signal Tmry sent from the control circuit 113. The stored contents are output as Id1 to Idn and input to the modulation signal generator 117.

The modulation signal generator 117 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 Idn, and an output signal thereof is applied to the surface conduction electron-emitting devices in the display panel 111 through terminals Doy1 to Doyn. Is done.

The electron-emitting device according to the present invention has an emission current I
e has the following basic characteristics. That is, electron emission has a clear threshold voltage Vth, and electron emission occurs only when a voltage equal to or higher than Vth is applied. For a voltage equal to or higher than the electron emission threshold, the emission current also changes in accordance with the change in the voltage applied to the device. In some cases, the value of the electron emission threshold voltage Vth or the degree of change of the emission current with respect to the applied voltage may be changed by changing the material, configuration, or manufacturing method of the electron emission element. I can say.

That is, when a pulse-like voltage is applied to the device, 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 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 output electron beam by changing the pulse width Pw.

Therefore, as a method of modulating the electron-emitting device in accordance with 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 117 has a constant value. A voltage modulation type circuit that generates a voltage pulse having a length but appropriately modulates the peak value of the pulse according to input data is used.

In order to implement the pulse width modulation method, the modulation signal generator 117 generates a voltage pulse having a constant peak value, but modulates the width of the voltage pulse appropriately according to input data. A circuit of a width modulation system is used.

By the series of operations described above, the image forming apparatus of the present invention can display a television using the display panel 111. Although not particularly described in the above description, the shift register 114 and the line memory 115 may be of a digital signal type or an analog signal type. In short, serial / parallel conversion and storage of image signals can be performed at a predetermined speed. It should be done.

When the digital signal type is used, it is necessary to convert the output signal DATA of the synchronizing signal separation circuit 116 into a digital signal. This can be achieved by providing an A / D converter at the output section of the 116. In connection with this, the circuit used for the modulation signal generator 117 is slightly different depending on whether the output signal of the line memory 115 is a digital signal or an analog signal.

First, the case of a digital signal will be described.
In the voltage modulation method, for example, a well-known D / A conversion circuit may be used as the modulation signal generator 117, and an amplification circuit or the like may be added as necessary.

In the case of the pulse width modulation method, the modulation signal generator 117 compares, for example, a high-speed oscillator, a counter for counting the number of waves output from the oscillator, and an output value of the counter with an output value of the memory. It can be configured by using a circuit in which a comparator (comparator) is combined.
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 may be added.

Next, the case of an analog signal will be described.
In the voltage modulation method, for example, an amplification circuit using a well-known operational amplifier or the like may be used as the modulation signal generator 117, and a level shift circuit or the like may be added as necessary. In the case of the pulse width modulation method, for example, a well-known voltage-controlled oscillation circuit (VCO) may be used, and an amplifier for amplifying the voltage up to the driving voltage of the surface conduction electron-emitting device may be added as necessary. You may.

In the image forming apparatus completed as described above, the external terminals Dox1 to Dox1
oxm, Doy1 to Doyn to apply a voltage to emit electrons, apply a high voltage to the metal back 95 or a transparent electrode (not shown) through the high voltage terminal Hv, accelerate the electron beam, and apply the high voltage to the fluorescent film 94. Collide,
An image can be displayed by 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. Is appropriately selected so as to be suitable for the use of the image forming apparatus. Also, the NTSC system has been described as an example of the input signal, but the present invention is not limited to this, and PAL, SECA
Various systems such as the M system may be used, and a TV signal composed of a larger number of scanning lines (for example, a high-definition TV including the MUSE system) may be used.

Next, the above-described ladder-type arrangement electron source substrate and an image forming apparatus using the same will be described with reference to FIGS. In FIG. 12, reference numeral 120 denotes an electron source substrate, 1
Reference numeral 21 denotes an electron-emitting device, and 122 denotes common wirings connected to the electron-emitting devices. A plurality of electron-emitting devices 121 are arranged on the substrate 120 in parallel in the X direction (this is called an element row). A plurality of such element rows are arranged on a substrate to form a ladder-type electron source substrate. By appropriately 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 may be applied to an element row that emits an electron beam, and a voltage equal to or lower than the electron emission threshold may be applied to an element row that does not emit an electron beam. Further, the common wirings Dx2 to Dx9 between the element rows, for example, Dx2 and Dx3 may be the same wiring.

FIG. 13 is a view showing the structure of an image forming apparatus provided with a ladder-shaped electron source. 130 is a grid electrode, 131 is a hole through which electrons pass, 132 is D
ox1, Dox2 ... Doxm outer terminal,
133, G1, G2 connected to the grid electrode 130,
... An outer terminal 120 made of Gn is an electron source substrate in which the common wiring between the element rows is the same as described above. 9 and 13 indicate the same members. The difference from the above-described image forming apparatus having a simple matrix arrangement (FIG. 9) is that a grid electrode 130 is provided between the electron source substrate 120 and the face plate 96.

A grid electrode 130 is provided between the substrate 120 and the face plate 96. The grid electrode 130 is capable of modulating the electron beam emitted from the surface conduction electron-emitting device, and allows the electron beam to pass through a stripe-shaped electrode provided orthogonal to the ladder-type element row. One circular hole 131 is provided for each element. The shape and installation position of the grid do not necessarily have to be as shown in FIG.
A large number of passage openings may be formed in a mesh shape as openings, and may be provided, for example, around or near the surface conduction electron-emitting device. The outer container terminal 132 and the outer grid container terminal 133 are electrically connected to a control circuit (not shown).

In the present image forming apparatus, the modulation signals for one line of an image are simultaneously applied to the grid electrode columns in synchronization with the sequential driving (scanning) of the element rows one by one.
By controlling the irradiation of each electron beam to the phosphor, an image can be displayed line by line.

Further, according to the present invention, it is possible to provide an image forming apparatus suitable for a display device such as a television conference system and a computer as well as a display device for a television broadcast. Further, it can be used as an image forming apparatus as an optical printer including a photosensitive drum or the like.
In addition, the present invention can be applied not only to a surface conduction type electron-emitting device but also to a cold cathode electron source such as a MIM type electron-emitting device and a field emission type electron-emitting device. Can also be applied.

[0062]

The present invention will be described below in detail with reference to examples.

Example 1 An image forming apparatus was manufactured using a matrix-type arranged electron source substrate (FIG. 9) having the surface conduction electron-emitting devices obtained as described above. The fixing method and the fixing device of the display panel in the image forming apparatus in this embodiment are shown in FIG. 1, and as described above, in FIG. 1, reference numeral 6 denotes a substrate 7 on which an electron-emitting device group (not shown) is mounted and The display panel includes a face plate 8 on which an image forming member (not shown) on which an image is formed by an electron beam emitted from the electron emitting element group, and a support frame 9 provided between the substrate and the face plate. is there. Reference numeral 14 denotes an aluminum reinforcing member and support device for supporting the entire surface of the substrate 7, which constitutes second support means. Reference numerals 15a to 15c denote aluminum support devices on the face plate side provided with elasticity by leaf springs. (A hatched portion in the figure) corresponding to a portion of the face plate that contacts the support frame 9
Hold down. When the aluminum support device and the glass face plate and / or the substrate are in local contact, it is desirable to lay silicon rubber or the like between the aluminum and the glass in order to avoid a steep temperature change. . The reinforcing member / support device 14 and the support devices 15a to 15c were fixed with screws.

Generally, the temperature distribution generated in the display panel is such that the temperature of the substrate is higher than the temperature of the face plate, so that the display panel is warped such that it is convex on the substrate side and concave on the face plate side. Depending on the size,
(Several tens μm to several tens mm). In the present embodiment, the elastic force of the divided support devices 15a to 15c is set such that the bending stiffness D is Da, Db ≧ Dc by changing each plate thickness and / or plate width. The elastic force (Da, D
b) ≧ the elastic force (Dc) at the peripheral edge of the display panel is for the purpose of allowing the above-mentioned warpage and reducing the load acting on the display panel.

The lower limit of the bending stiffness of the split support device was determined because the weight of the display panel could be supported when the face plate was turned downward, and the upper limit was determined to be less than the bending stiffness of the display panel. Note that the split support device 15c at the peripheral end of the display panel does not have to be able to support the display panel weight with the other split support devices 15a and 15b (Dc = 0).

Reference numeral 19 denotes the display panel 6 and the supporting device 14,
15 and a panel housing that contains the drive circuit board 10 that emits image display signals. Each member was fixed to the panel housing 19 by screws. Note that the split support device 1
5a to 5c does not have a problem even if it has a structure in which it is fixed to the panel housing 11 on the face plate side instead of being fixed to the reinforcing member / support device 14 with screws. In this case, the split support devices 15a to 15c can be regarded as the deformation of the nine protrusions of the present invention.

A method of manufacturing a display panel including the face plate 8, the support frame 9, and the electron source substrate 7 will be briefly described below. Details are given in the embodiments. First, frit glass is applied by a dispenser to the face plate 8 on which the image forming member is mounted in advance by the method described above, and the support frame 9 is adjusted to a desired position.
Calcination at 430 ° C. for 10 minutes. Next, frit glass is applied to the electron source substrate 7 with a dispenser, and the support frame 9 and the face plate 8 prepared above are aligned with each other at a predetermined position.
Temporary baking for 0 minutes and main baking for 10 minutes at 410 ° C. were performed to produce a display panel.

After the completion of the assembling process, an exhaust pipe (not shown) is used to evacuate the inside of the display panel manufactured in the above process.
Through the display panel, approximately 10 −6 torr
Vacuum was exhausted until the exhaust pipe was sealed. The panel unit to which the display panel, the reinforcing member / supporting device 14 and the supporting devices 15a to 15c on the face plate side are fixed, and the driving circuit board 10 were screwed (not shown) to the panel housing 19.

As described above, in the method of fixing the display panel in the image forming apparatus in which the face plate above the support frame and the entire surface of the electron source substrate are supported and fixed, the display panel is allowed to be warped and an extra load is applied to the display panel. Thus, the display panel can be fixed safely and stably, and no vacuum leak or breakage from the lead-out electrode portion has occurred.

Example 2 An image forming apparatus was manufactured using a ladder-type arranged electron source substrate (FIG. 13) having a surface conduction electron-emitting device obtained as described above.

FIG. 2 shows a fixing method and a fixing device of a display panel in an image forming apparatus according to the present embodiment. In FIG. 2, reference numeral 6 denotes a substrate 7 on which an electron-emitting device group (not shown) is mounted.
And a face plate 8 on which an image forming member (not shown) on which an image is formed by an electron beam emitted from the electron emitting element group, and a support frame 9 installed between the substrate 7 and the face plate 8. It is a panel. 11
Is a panel housing / support device made of resin on the face plate side on which a projection 16 made of silicon rubber having elasticity is provided on a contact surface with the display panel 6 (first support means)
And a back surface portion (a shaded portion in the drawing) corresponding to a portion of the face plate that contacts the support frame 9 is pressed. 1
Reference numeral 7 denotes a support device on the side of the substrate 7 corresponding to a second support means, and a substrate abutting projection 18 that contacts a back surface of the substrate corresponding to a portion that contacts the support frame 9 is provided. The face plate abutting projection 16 and the substrate abutting projection 18 are provided with a projection having a large cross-sectional area at the center of the periphery of the display panel so as to increase the compressive elasticity, and a small cross-sectional area at the peripheral end. A projection having a small compression elastic force was provided.

The lower end of the display panel is configured to abut the panel housing and support device 11 to support the weight of the display panel. The elastic deformation range of the projection is desirably equal to or larger than the amount of warpage displacement (several tens μm to several mm) when the panel is driven, and if the weight of the display panel can be supported,
The substrate abutting projection and the face plate abutting projection may be provided only at the central portion of the periphery of the display panel. Alternatively, the substrate abutting projection 18 may be provided on the drive circuit board instead of the support device 17. Reference numeral 19 denotes the display panel 6, the support device 17, and the drive circuit board 10 for generating an image display signal.
Is a panel housing on the substrate side that incorporates. Each member was fixed to the panel housing 19 by screws. The method of creating the display panel is the same as in the first embodiment.

[0073]

As described above, in the flat-panel image forming apparatus according to the present invention in which the face plate and the substrate are supported and fixed, the display panel is allowed to be warped, and no extra load is applied to the display panel, so that the display panel is safe and stable. The display panel can be fixed, and there is no vacuum leak or breakage from the extraction electrode portion.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view illustrating an example of an embodiment of the present invention.

FIG. 2 is a schematic perspective view illustrating another example of the embodiment of the present invention.

FIG. 3 is a schematic plan view and a cross-sectional view illustrating a basic configuration of a surface conduction electron-emitting device applied to the present invention.

FIG. 4 is a schematic sectional view showing a basic configuration of a vertical surface conduction electron-emitting device applied to the present invention.

FIG. 5 is a schematic cross-sectional view showing an example of a method for manufacturing a surface conduction electron-emitting device applied to the present invention.

FIG. 6 is a diagram showing an example of a voltage waveform of energization forming at the time of manufacturing a surface conduction electron-emitting device.

FIG. 7 is a schematic configuration diagram of a measurement evaluation device for measuring electron emission characteristics of an electron emission element.

FIG. 8 is a configuration diagram illustrating an example of an electron source having a simple matrix arrangement.

FIG. 9 is a schematic configuration diagram illustrating an example of an image forming apparatus applied to the present invention.

FIG. 10 is an explanatory diagram of a fluorescent film used in the image forming apparatus.

FIG. 11 is a block diagram of a drive circuit for performing display in accordance with an NTSC television signal and a diagram showing an image forming apparatus having the drive circuit.

FIG. 12 is a configuration diagram illustrating an example of an electron source having a ladder arrangement.

FIG. 13 is a schematic configuration diagram of another example of an image forming apparatus applied to the present invention.

FIG. 14 is a schematic plan view showing an example of a conventional surface conduction electron-emitting device.

FIG. 15 is a schematic perspective view illustrating an example of a conventional display panel fixing method and a fixing device.

FIG. 16 is a schematic perspective view illustrating another example of a conventional display panel fixing method and a fixing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2, 3 Element electrode 4 Conductive thin film 5 Electron emission part 6 Display panel 7 Substrate 8 Face plate 9 Support frame 10 Drive circuit board 11 Panel housing and support device 12 Support device 13 Elastic body 14 Reinforcement member and support device 15a -C split support device 16 face plate abutting projection 17 support device 18 substrate abutting projection 19 panel housing 20 double-sided tape 21 step forming portion 70 ammeter 71 power supply 72 ammeter 73 high voltage power supply 74 anode electrode 75 vacuum device 76 Exhaust pump 81 Electron source substrate 82 X direction wiring 83 Y direction wiring 84 Surface conduction electron-emitting device 85 Connection 91 Rear plate 92 Support frame 93 Glass substrate 94 Fluorescent film 95 Metal back 96 Face plate 97 High voltage terminal 98 Display panel 101 Black conductive Material 102 Phosphor 111 Table Display panel 112 Scanning circuit 113 Control circuit 114 Shift register 115 Line memory 116 Synchronous signal separation circuit 117 Modulation signal generator, Vx and Va: DC voltage source 120 Electron source substrate 121 Electron emitting element 122 Common wiring group 130 composed of Dx1 to Dx10 130 Grid electrode 131 Vacancy 132 Outer container terminal composed of Dox1 to Doxm 133 Outer container terminal composed of G1 to Gn

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-146654 (JP, A) JP-A-4-55822 (JP, A) JP-A-4-75021 (JP, A) 53331 (JP, U) Japanese Utility Model 5-50428 (JP, U) Japanese Utility Model 4-23380 (JP, U) Japanese Utility Model 62-137468 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G09F 9/00

Claims (6)

(57) [Claims] 1. A substrate on which an electron-emitting device group is mounted (A)
And a face plate (B) mounted with an image forming member on which an image is formed by irradiation of an electron beam emitted from the electron emitting element group, and arranged to face the substrate (A)
And a display panel comprising a support frame (C) between the substrate (A) and the face plate (B) is fixed in a housing, wherein the face plate (B) On a surface opposite to the surface facing the substrate (A), a plurality of peripheral portions corresponding to a portion where the face plate (B) and the support frame (C) are in contact with each other. A first support unit, and a second support unit fitted with the display panel and coupled to the plurality of first support units, wherein each of the plurality of first support units is The point of contact with the peripheral part is the central part of each side constituting the peripheral part, and
And that the elastic force of the first support means contacting a part other than the central part is smaller than the elastic force of the first support means contacting the central part. A flat plate type image forming apparatus. 2. A substrate (A) on which an electron-emitting device group is mounted.
And a face plate (B) mounted with an image forming member on which an image is formed by irradiation of an electron beam emitted from the electron emitting element group, and arranged to face the substrate (A)
When the display panel consisting said substrate (A) and said faceplate (B) the support frame between the (C), a flat type image forming apparatus comprising fixed within the housing, before Kikatamitai, First support means forming a front frame having a window; second support means arranged in the housing, which fits with the display panel and is coupled to the first support means; and the face plate. (B) facing the substrate (A)
So that it touches multiple points on the surface opposite to the
A plurality of elastic projections provided on the back surface of the frame, each of which comes into contact with the face plate (B).
The place is the face plate (B) and the support frame
(C) The face press corresponding to a portion in contact with
A portion of the peripheral portion of the sheet (B), in which each of the protrusions contacts at the peripheral portion ,
A central part of each side constituting the peripheral part and the central part
A flat plate type image forming apparatus, wherein the elastic force of the projections which are located outside and contact the parts other than the central part is smaller than the elastic force of the projections which contact the central part. 3. The second support means has a back plate.
The back plate comes into contact with the substrate (A) and the support frame (C)
Elastic projections are provided at multiple locations on the peripheral edge
The flat plate type according to claim 2, wherein the flat plate type has a raised portion.
Image forming device. 4. A projecting portion of the second support means includes a central portion of each side constituting the peripheral portion of the back plate and a central portion of the side portion.
It is outside the site, than the elastic force of the protrusion of the second supporting means at the said central portion, the elastic force of the protrusion of the second supporting means at the portion other than the central portion is small The flat plate type image forming apparatus according to claim 3, wherein: 5. The back plate drives the electron-emitting device group.
The substrate according to claim 3 or 4, wherein the substrate has a driving circuit mounted thereon.
The flat plate type image forming apparatus as described in the above. 6. A surface conduction type electron as said electron-emitting device.
6. A method as claimed in claim 1, wherein a discharge element is used.
2. The flat panel image forming apparatus according to claim 1.