JPH10198303A - Image forming device - Google Patents

Abstract

(57) [Summary] In an image forming apparatus, even when the amount of emitted electrons per unit time is increased and when the brightness of an image is increased, the electron trajectory does not bend and discharge does not occur. The task is not to do so. SOLUTION: An electron source in which a plurality of electron-emitting devices are arranged, a phosphor which emits light by irradiation of an electron beam emitted from the electron source, and a plurality of phosphors arranged between the electron source and the phosphor. The driving order of the plurality of electron-emitting devices is skipped so that the phosphor near the spacer is not continuously irradiated with the electron beam. . The image forming apparatus may further include a driving unit that drives the plurality of electron-emitting devices in a different order from the order of driving the plurality of electron-emitting devices so that the phosphor near the spacer is not continuously irradiated with the electron beam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, a driving method thereof, and an image forming method thereof.
In particular, the present invention relates to an image forming apparatus provided with a spacer inside the envelope for supporting the atmospheric pressure applied to the envelope of the apparatus from inside the envelope, a driving method thereof, and an image forming method thereof.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitting devices, a hot cathode device and a cold cathode device, are known. Among them, in the cold cathode device, for example, a surface conduction type emission device, a field emission type device (hereinafter referred to as “FE type”), and a metal / insulating layer / metal type emission device (hereinafter referred to as “MIM type”) , Etc. are known.

[0003] As this surface conduction type emission element, for example, MIElinson, Radio Eng. Electron Phys., 10, 129
0, (1965) and other examples described later. The surface conduction electron-emitting device utilizes a phenomenon in which 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, in addition to the use of a thin film of SnO ₂ according to the Ellingson, etc., by an Au thin film [G.Dittmer: "Thin Soli
d Films ", 9,317 (1972) ] and, In ₂ O ₃ / SnO ₂ by thin film [M.Hartwell and CGFonstad:" IEEE Tra
ns. ED Conf. ", 519 (1975)] and those based on carbon thin films [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, 22 (19)
83)] have been reported. As a typical example of the device configuration of these surface conduction electron-emitting devices, FIG.
1 shows a plan view of a device by Hartwell et al. In the figure,
Reference numeral 3001 denotes a substrate, and 3004 denotes a conductive thin film made of a metal oxide formed by sputtering. Conductive thin film 300
4 is formed in an H-shaped planar shape as shown.
An electron emission portion 3005 is formed by subjecting the conductive thin film 3004 to an energization process called energization forming described later. The interval L in the figure is 0.5 to 1 [mm], W
Is set at 0.1 [mm]. For convenience of illustration, the electron emitting portion 3005 is shown in a rectangular shape at the center of the conductive thin film 3004, but this is a schematic one.
It does not faithfully represent the actual position and shape of the electron-emitting portion.

In the above-described surface conduction electron-emitting device, including the device described by M. Hartwell et al., The conductive thin film 3004 is subjected to an energization process called energization forming before the electron emission, so that the electron emission is performed. Forming part 3005 was common. That is, the energization forming means applying a constant DC voltage to both ends of the conductive thin film 3004 or applying a DC voltage which is stepped up at a very slow rate of, for example, about 1 V / min. The electron emitting portion 30 in a state where the conductive thin film 3004 is locally broken, deformed, or deteriorated, and is in an electrically high resistance state.
05 is formed. Note that a crack is generated in a part of the conductive thin film 3004 that is locally broken, deformed, or altered. When an appropriate voltage is applied to the conductive thin film 3004 after the energization forming, electrons are emitted in the vicinity of the crack.

[0005] Examples of the FE type are, for example, WPDyke.
& W.W.Dolan, “Field emission”, Advance in Electron P
hysics, 8, 89 (1956) or CASpindt, “Physic
al properties of thin-film field emission cathode
s with molybdenum cones “, J. Appl. Phys., 47, 5248 (1
976). As a typical example of the FE-type element configuration, FIG. 18 shows a cross-sectional view of the element by CASpindt et al. Described above. In the figure, reference numeral 3010 denotes a substrate;
Reference numeral 1 denotes an emitter wiring made of a conductive material, 3012 denotes an emitter cone, 3013 denotes an insulating layer, and 3014 denotes a gate electrode. In this element, an appropriate voltage is applied between the emitter cone 3012 and the gate electrode 3014 to cause field emission from the tip of the emitter cone 3012. As another element configuration of the FE type, FIG.
There is also an example in which an emitter and a gate electrode are arranged on a substrate almost in parallel with the substrate plane instead of the laminated structure as described above.

As an example of the MIM type, for example,
CAMead, “Operation of tunnel-emission Devices,
J. Appl. Phys., 32, 646 (1961) and the like are known. MI
FIG. 19 shows a typical example of the M-type element configuration. The figure is a sectional view, in which 3020 is a substrate and 3021
Is a lower electrode made of a metal, 3022 is a thin insulating layer having a thickness of about 100 angstroms, and 3023 is a thickness of 80 to 30.
The upper electrode is made of a metal having a thickness of about 0 Å.
In the MIM type, the upper electrode 3023 and the lower electrode 3021
By applying an appropriate voltage between the upper electrode 302
3 to emit electrons from the surface.

[0007] The above-mentioned cold cathode device can obtain electron emission at a lower temperature than the hot cathode device, and therefore has a heating head.
No need for tar. Therefore, the structure is simpler than that of the hot cathode element, and a fine element can be produced. Also,
Even if a large number of elements are arranged on a substrate at a high density, problems such as thermal melting of the substrate hardly occur. Also, unlike the hot cathode element, which operates by heating the heater, which has a low response speed, the cold cathode element has the advantage of a high response speed.

For this reason, research for applying cold cathode devices has been actively conducted. For example, the surface conduction electron-emitting device has the advantage of being able to form a large number of devices over a large area since it has a particularly simple structure and is easy to manufacture among cold cathode devices. Therefore, as disclosed in Japanese Patent Application Laid-Open No. 64-31332 by the present applicant, a method for arranging and driving a large number of elements has been studied. As for the application of the surface conduction electron-emitting device, for example, an image forming apparatus such as an image display device and an image recording device, a charged beam source, and the like have been studied.

[0009] In particular, as an application to an image display apparatus, for example, US Pat.
As disclosed in JP-A-257551 and JP-A-4-28137, an image display device using a combination of a surface conduction electron-emitting device and a phosphor that emits light by irradiation with an electron beam has been studied. I have. An image display device using a combination of a surface-conduction emission device and a phosphor is:
Characteristics superior to other conventional image display devices are expected. For example, compared to a liquid crystal display device that has become widespread in recent years, it can be said that it is superior in that it does not require a backlight because it is a self-luminous type and that it has a wide viewing angle.

A method of driving a large number of FE types in a row is disclosed in, for example, US Pat. No. 4,904,895 by the present applicant. As an example of applying the FE type to an image display device, for example, a flat panel display device reported by R. Meyer et al. Is known. That is, [R.Meyer: “Rece
nt Development on Microtips Display at LETI “, Tec
h.Digest of 4th Int.Vacuum Microelectronics Con
f., Nagahama, pp. 6-9 (1991)].

An example in which a number of MIM types are arranged and applied to an image display device is disclosed in, for example, Japanese Patent Application Laid-Open No.
No. 5,557,838.

Among the image forming apparatuses using the above-described electron-emitting devices, a flat display device having a small depth has been attracting attention as a replacement for a cathode-ray tube display device because of its space saving and light weight. .

FIG. 20 is a perspective view showing an example of a display panel portion forming a flat-panel type image display device. The panel is partially cut away to show the internal structure. In the figure, 31
15 is a rear plate, 3116 is a support frame as a side wall, 3
Reference numeral 117 denotes a face plate, and a rear plate 311
5. The side wall 3116 and the fuse plate 3117 form an envelope (airtight container) for maintaining the inside of the display panel in a vacuum. The substrate 3111 is fixed to the rear plate 3115.
On the top, N × M cold cathode elements 3112 are formed. However, N and M are positive integers of 2 or more, and are appropriately set according to the target number of display pixels. In addition, the N ×
As shown in FIG. 20, M cold cathode elements 3112
The row wirings 3113 and the N column wirings 3114 are wired. These substrate 3111, cold cathode element 3112, row direction wiring 3113, and column direction wiring 311
The part constituted by 4 is called a multi-electron beam source. An insulating layer (not shown) is formed between at least the intersections of the row wirings 3113 and the column wirings 3114 to maintain electrical insulation.

On the lower surface of the face plate 3117, a fluorescent film 3118 made of a fluorescent material is formed.
Phosphors (not shown) of three primary colors of red (R), green (G), and growth (B) are separately applied. In addition, a black body (not shown) for improving the contrast is provided between the respective color phosphors forming the fluorescent film 3118, and further, the fluorescent film 3118 is provided.
A metal back 3119 made of Al or the like is formed on the rear plate 3115 side.

Further, Dx1-Dxm and Dy1-D
Symbols yn and Hv are electric connection terminals having an airtight structure provided for electrically connecting the display panel to an electric circuit for scanning drive (not shown). Dx1 to Dxm are the row direction wiring 3113 of the multi-electron beam source and Dy1 to Dy.
n is the column direction wiring 3114 of the multi-electron beam source and Hv
Are electrically connected to the metal back 3119, respectively.

The inside of the hermetic container is maintained at a vacuum of about 10 −6 Torr, and as the display area of the image display device increases, the rear plate 3115 and the rear plate 3115 due to a pressure difference between the inside and the outside of the hermetic container. Means for preventing deformation or destruction of the face plate 3117 is required. The method of increasing the thickness of the rear plate 3115 and the face plate 3116 not only increases the weight of the image display device, but also causes image distortion and parallax when viewed from an oblique direction. In contrast, FIG.
Is provided with a structural support (called a spacer or a rib) 3120 made of a relatively thin glass plate and supporting the atmospheric pressure. Thus, the substrate 3111 on which the multi-beam electron source is formed and the fluorescent film 31
The space between the face plates 3116 where the 18 is formed is usually maintained at a sub-millimeter to several millimeters, and the inside of the airtight container is maintained at a high vacuum as described above.

In the image display apparatus using the display panel described above, when a voltage is applied to each cold cathode element 3112 through the external terminals Dx1 to Dxm and Dy1 to Dyn, electrons are emitted from each cold cathode element 3112. At the same time, a high voltage of several hundred [V] to several [kV] is applied to the metal back 3119 through the external terminal Hv to accelerate the emitted electrons and cause them to collide with the inner surface of the face plate 3117. As a result, the phosphors of each color forming the fluorescent film 3118 are excited and emit light, and an image is displayed.

[0018]

The display panel of the image display device described above has the following problems.

First, there is a possibility that spacer charging may be caused by a part of the electrons emitted from the vicinity of the spacer 3120 hitting the spacer 3120 or by ionized ions attached to the spacer by the action of the emitted electrons. is there. The electrons emitted from the cold cathode element 3112 due to the charging of the spacer are bent in their trajectories, reach a position different from the normal position on the phosphor, and the image near the spacer is distorted and displayed.

Second, in order to accelerate electrons emitted from the cold cathode device 3112, a high voltage of several hundred V or more (ie, 1 k) is applied between the multi-beam electron source and the face plate 3117.
V / mm or more), the spacer 3
There is a concern about creeping discharge on the surface of the H.120. In particular, when the spacer is charged as described above, discharge may be induced.

In order to solve this problem, it has been proposed to remove a charge by causing a small current to flow through the spacer (Japanese Patent Laid-Open Nos. 57-118355 and 61-124031). There, a high-resistance thin film is formed on the surface of an insulating spacer so that a minute current flows on the surface of the spacer.

However, when the amount of emitted electrons per unit time is increased in order to increase the luminance, there has been a problem that the charge removal capability of the spacer is insufficient. In that case,
The above two problems occur again.

The present invention overcomes the above-mentioned problems of the image display apparatus. Even when the amount of emitted electrons per unit time is increased and the brightness of the image is increased, the electron trajectory is improved. An object of the present invention is to provide an image forming method which does not bend and does not discharge, and an image forming apparatus using the same.

[0024]

In order to solve the above problems, an image forming apparatus according to the present invention has the following arrangement.

That is, an electron source having an electron-emitting device, a phosphor that emits light by irradiation of an electron beam emitted from the electron source, and an electric source electrically connected and arranged between the electron source and the phosphor. Having a semiconductive spacer,
It is characterized in that timings for driving pixels near the spacer are dispersed. Further, the semi-conductive spacer,
It has a semiconductive film on the surface.

The timing of irradiating the electron beam is such that the image region is divided into large regions so that the spacers are evenly arranged, and the pixels in each large region are united so that the pixels in each large region do not continuously emit light. It is characterized by driving while skipping.

In the driving order in each of the large areas,
The pixel is divided into several small areas according to the distance from the spacer, and the small areas near the spacer are not arranged in a continuous order.

The electron source has a plurality of electron-emitting devices connected by wiring, and a semiconductive film on the surface of the spacer is electrically connected to the wiring and the phosphor. .

The electron source has a plurality of electron-emitting devices connected by wiring, and the spacer is arranged between the wiring and the phosphor so that a longitudinal direction is parallel to the wiring. And a semiconductive film on the surface of the spacer is electrically connected to the wiring and the phosphor.

The electron source has a plurality of electron-emitting devices arranged in a matrix with a plurality of row-direction wirings and a plurality of column-direction wirings. It is electrically connected to the column wiring and the phosphor.

The electron source has a plurality of electron-emitting devices arranged in a matrix with a plurality of row-direction wirings and a plurality of column-direction wirings, and the spacer is a rectangular spacer. The row direction wiring or the column direction wiring is disposed between the phosphor and the phosphor so that the row direction wiring or the column direction wiring is parallel to the phosphor. Alternatively, it is electrically connected to the column wiring and the phosphor. Further, the electron-emitting device may be a cold cathode device or a surface conduction electron-emitting device.

[Operation] As described above, the most characteristic feature of the image forming apparatus of the present invention is that the driving is performed by dispersing the vicinity of the conductive spacers without being continuous. As a result, the charge amount of each spacer can be reduced and the charge relaxation time can be increased, and a high-quality image forming apparatus free from beam bending and spacer section discharge can be realized.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image forming apparatus according to the present invention will be described in detail with reference to the drawings.

(1) Configuration of Display Panel of Image Forming Apparatus First, the configuration and manufacturing method of a display panel of an image forming apparatus to which the present invention is applied will be described with reference to specific examples.

FIG. 1 is a perspective view of a display panel used in the embodiment, in which a part of the panel is cut away to show the internal structure. In the figure, 1015 is a rear plate, 1
Reference numeral 016 denotes a side wall and 1017 denotes a face plate. The rear plate 1015, the side wall 1016 and the face plate 1017 form an airtight container for maintaining the inside of the display panel at a vacuum. When assembling an airtight container, it is necessary to seal the joints of each member to maintain sufficient strength and airtightness.For example, apply frit glass to the joints, and in air or nitrogen atmosphere, Sealing was achieved by baking at 400 to 500 degrees for 10 minutes or more. A method of evacuating the inside of the airtight container to a vacuum will be described later. Further, since the inside of the hermetic container is maintained at a vacuum of about 10 −6 [Torr], it is used as an anti-atmospheric structure for the purpose of preventing the hermetic container from being destroyed due to atmospheric pressure or unexpected impact. A spacer 1020 is provided as appropriate.

The rear plate 1015 has a substrate 1011
Is fixed, but the cold cathode element 1012 is provided on the substrate.
Are formed N × M. Here, N and M are positive integers of 2 or more, and are appropriately set according to the target number of display pixels. For example, in a display device for displaying high-definition television, N = 3000, M = 100
It is desirable to set the number to 0 or more. The N × M cold cathode elements are arranged in a simple matrix by M row-directional wirings 1013 and N column-directional wirings 1014.
The part constituted by 1011 to 1014 is called a multi-electron beam source.

The material, shape and manufacturing method of the cold cathode device are not limited as long as the multi-electron beam source used in the image forming apparatus of the present invention is an electron source in which cold cathode devices are arranged in a simple matrix wiring. Therefore, for example, a cold cathode device such as a surface conduction type emission device, an FE type, or an MIM type can be used.

Next, the structure of a multi-electron beam source in which a surface conduction electron-emitting device (described later) as a cold cathode device is arranged on a substrate and wired in a simple matrix will be described.

FIG. 2 is a plan view of the multi-electron beam source formed on the substrate 1011 in the display panel of FIG. On the substrate 1011, surface conduction type emission elements similar to those shown in FIG. 102 to be described later are arranged, and these elements are wired in a simple matrix by row direction wiring electrodes 1013 and column direction wiring electrodes 1014. An insulating layer (not shown) is formed between the row-directional wiring electrodes 1013 and the column-directional wiring electrodes 1014 at the intersections of the electrodes to maintain electrical insulation. FIG. 3 shows a cross section taken along line BB ′ of FIG.

The multi-electron source having such a structure is as follows.
After previously forming a row direction wiring electrode 1013, a column direction wiring electrode 1014, an inter-electrode insulating layer (not shown), a device electrode of a surface conduction type emission device, and a conductive thin film on a substrate,
Row direction wiring electrode 1013 and column direction wiring electrode 1014
The device was manufactured by supplying current to each element through the device and performing an energization forming process (described later) and an energization activation process (described later).

In the present embodiment, the substrate 1011 of the multi-electron beam source is fixed to the rear plate 1015 of the airtight container.
When 11 has a sufficient strength, the substrate 10 of the multi-electron beam source is used as a rear plate of the hermetic container.
11 itself may be used.

A fluorescent film 1018 is formed on the lower surface of the face plate 1017. Since the present embodiment is a color display device, C
Phosphors of three primary colors of red, green and blue used in the field of RT are separately applied. The phosphor of each color is, for example, as shown in FIG.
(A), the stripes are separately applied, and a black conductor 1010 is provided as a black stripe between phosphor stripes. Black conductor 101
The purpose of providing 0 is to prevent the display color from being shifted even if there is a slight shift in the irradiation position of the electron beam, to prevent the reflection of external light, and to prevent the display contrast from lowering.
This is to prevent the fluorescent film from being charged up by the electron beam. Although graphite is used as a main component for the black conductor 1010, any other material may be used as long as it is suitable for the above purpose.

The method of applying the three primary color phosphors is not limited to the stripe arrangement shown in FIG. 4A, but may be, for example, a delta arrangement as shown in FIG. Other arrangements may be used.

In this embodiment, the fluorescent film 10
As shown in FIG. 5, as shown in FIG. 5, each color phosphor 21 a adopts a stripe shape extending in the column direction (Y direction), and the black conductor 21 b is not limited to each color phosphor (R, G, B) 21 a, A phosphor film arranged so as to separate each pixel in the Y direction is also used, and the spacer 1020 is formed of a metal within the black conductor 21b region (line width 300 micrometers) parallel to the row direction (X direction). Arranged via the back 1019. When performing the above-described sealing, the phosphors 2
Since the elements 1a and the elements arranged on the substrate 1011 must correspond to each other, the rear plate 1015, the face plate 1017, and the spacer 120 are sufficiently aligned.

When a monochrome display panel is manufactured, a single-color fluorescent material may be used for the fluorescent film 1018 over the entire face plate, and a black conductive material may not necessarily be used.

A metal back 1019 known in the field of CRTs is provided on the surface of the fluorescent film 1018 on the rear plate side.
Is provided. The purpose of providing the metal back 1019 is
A part of the light emitted from the fluorescent film 1018 is specularly reflected to improve the light utilization rate, and the fluorescent film 101
8 to protect it, to function as an electrode for applying an electron beam acceleration voltage, and to function as a conductive path for the excited electrons of the fluorescent film 1018. The metal back 1019 was formed by forming a fluorescent film 1018 on a faceplate substrate 1017, smoothing the surface of the fluorescent film, and vacuum-depositing Al thereon.
Note that when a fluorescent material for low voltage is used for the fluorescent film 1018, the metal back 1019 is not used.

Although not used in the present embodiment, for the purpose of applying an acceleration voltage and improving the conductivity of the fluorescent film, for example, ITO is used as a material between the face plate substrate 1017 and the fluorescent film 1018. May be provided.

FIG. 6 is a schematic cross-sectional view taken along the line AA ′ of FIG. 1, and the numbers of the respective parts correspond to those of FIG. Spacer 102
Numeral 0 indicates that a high resistance film 1020b is formed on the surface of the insulating member 1020a for the purpose of preventing electrification, and the inside of the face plate 1017 (metal back 1019 and the like) and the substrate 1
011 (row direction wiring 1013 or column direction wiring 1
014) on the contact surface of the spacer facing the low resistance film 1020
c is formed of a member having a film formed thereon, and is arranged by a necessary number and at a necessary interval to achieve the above object,
It is fixed to the inside of the face plate 1017 and the surface of the substrate 1011 by a bonding material 1041. The high-resistance film 1020b is formed on the surface of the insulating member 1020a.
The low-resistance film 1020 c is formed on at least the surface of the airtight container exposed to the vacuum, and is formed on the spacer 1020.
And the face plate 10 via the bonding material 1041.
17 (metal back 1019 etc.) and substrate 101
1 (row direction wiring 1013 or column direction wiring 101)
4) is electrically connected. In the embodiment described here, the shape of the spacer 1020 is a thin plate, is arranged in parallel with the row wiring 1013, and is electrically connected to the row wiring 1013.

As the spacer 1020, the substrate 1011
Has insulating properties enough to withstand high voltage applied between the upper row direction wiring 1013 and column direction wiring 1014 and the metal back 1019 on the inner surface of the face plate 1017;
In addition, it is necessary to have conductivity enough to prevent the surface of the spacer 1020 from being charged. This is as described above.

The insulating member 1020a of the spacer 1020
Examples thereof include quartz glass, glass with a reduced impurity content such as Na, soda lime glass, and ceramic members such as alumina. The insulating member 10
Preferably, 20a has a coefficient of thermal expansion close to that of the member forming the airtight container and the substrate 1011.

As described above, the surface resistance value of the high resistance film 1020b is 10 5 [Ω / □] in consideration of maintaining the antistatic effect and suppressing power consumption due to leak current. Is preferably in the range of the 12th power [Ω / □].
Are used.

The low-resistance film 1020c is formed of the high-resistance film 1
What is necessary is just to select a resistance value sufficiently lower than 020b.
Metals or alloys such as i, Cr, Au, Mo, W, Pt, Ti, Al, Cu, Pd, and Pd, Ag. Au, RuO2, Pd-Ag or the like of the metal or metal oxide and formed printed conductors of glass or the like, or is suitably selected from In ₂ O ₃ -SnO ₂ semiconductor materials such as transparent conductors and polysilicon or the like.

The bonding material 1041 needs to have conductivity so that the spacer 1020 is electrically connected to the row wiring 1013 and the metal back 1019. That is, frit glass to which a conductive adhesive, metal particles, or a conductive filler is added is preferable.

As shown in FIG. 1, Dx1 to Dxm, Dy1 to Dyn, and Hv are electric connection terminals having an airtight structure provided for electrically connecting the display panel to an electric circuit (not shown). It is. Dx1 to Dxm are row-directional wirings 1013 of the multi-electron beam source, Dy1 to Dyn are column-directional wirings 1014 of the multi-electron beam source, and Hv is a face play.
It is electrically connected to the metal back 1019.

In order to evacuate the inside of the hermetic container to a vacuum, after assembling the hermetic container, an exhaust pipe (not shown) and a vacuum pump are connected, and the inside of the hermetic container is raised to 10 −7 [T
orr]. Thereafter, the exhaust pipe is sealed, but a getter film (not shown) is formed at a predetermined position in the airtight container immediately before or after the sealing in order to maintain the degree of vacuum in the airtight container. The getter film is, for example, a film formed by heating and depositing a getter material containing Ba as a main component by a heater or high-frequency heating.
Due to the adsorbing action of the getter film, the inside of the airtight container is 1 × 10 −5 or 1 × 10 −7 [Torr].
Is maintained at a vacuum degree.

In the image forming apparatus using the display panel described above, when a voltage is applied to each of the cold cathode devices 1012 through the terminals Dx1 to Dxm and Dy1 to Dyn outside the container, electrons are emitted from each of the cold cathode devices 1012. At the same time, a high voltage of several hundred [V] to several [kV] is applied to the metal back 1019 through the external terminal Hv to accelerate the emitted electrons and collide with the inner surface of the face plate 1017. As a result, the phosphor of each color forming the fluorescent film 1018 is excited and emits light, and an image is displayed.

Normally, the voltage applied to the surface conduction electron-emitting device 1012 of the present invention, which is a cold cathode device, is about 12 to 16 [V], and the distance d between the metal back 1019 and the cold cathode device 1012 is 0.1 [mm]. ] To about 8 [mm] and a voltage of 0.1 [k] between the metal back 1019 and the cold cathode element 1012.
V] to about 10 [kV].

The basic configuration and manufacturing method of the display panel according to the embodiment of the present invention and the outline of the image forming apparatus have been described above.

(2) Method of Manufacturing Multi-Electron Beam Source Next, a method of manufacturing the multi-electron beam source used in the display panel of the above embodiment will be described. The material, shape, and manufacturing method of the cold cathode device are not limited as long as the multi-electron beam source used in the image forming apparatus of the present invention is an electron source in which the cold cathode devices are arranged in a simple matrix. Therefore, for example, a cold cathode device such as a surface conduction type emission device, an FE type, or an MIM type can be used. However, in a situation where a display device having a large display screen and an inexpensive display device is required, among these cold cathode devices, a surface conduction type emission device is particularly preferable. That is, in the FE type, since the relative position and shape of the emitter cone and the gate electrode greatly affect the electron emission characteristics, extremely high-precision manufacturing technology is required. However, this requires a large area and a reduction in manufacturing cost. Is a disadvantageous factor to achieve. In the case of the MIM type, it is necessary to make the thicknesses of the insulating layer and the upper electrode thin and uniform, which is also a disadvantageous factor in achieving a large area and a reduction in manufacturing cost. On the other hand, since the surface conduction electron-emitting device has a relatively simple manufacturing method, it is easy to increase the area and reduce the manufacturing cost. In addition, the inventors have found that among the surface conduction electron-emitting devices, those in which the electron-emitting portion or its peripheral portion is formed of a fine particle film have particularly excellent electron-emitting characteristics and can be easily manufactured. Therefore, it can be said that it is most suitable for use in a multi-electron beam source of a high-brightness, large-screen image forming apparatus. Therefore, in the display panel of the above embodiment, a surface conduction electron-emitting device in which the electron-emitting portion or its peripheral portion is formed of a fine particle film is used. Therefore, the basic structure, manufacturing method and characteristics of a suitable surface conduction electron-emitting device will be described first, and then the structure of a multi-electron beam source in which a large number of devices are arranged in a simple matrix will be described.

(I) Preferable Device Configuration and Manufacturing Method of Surface Conduction Emitting Element A typical configuration of a surface conduction electron-emitting device in which an electron-emitting portion or its peripheral portion is formed of a fine particle film is a flat type or a vertical type. There are two types.

(Ii) Planar surface conduction electron-emitting device First, the structure and manufacturing method of a plane surface conduction electron-emitting device will be described. FIG. 7 is a plan view (a) and a cross-sectional view (b) for describing the configuration of a planar surface conduction electron-emitting device. In the figure, 1101 is a substrate, 11
02 and 1103 are device electrodes, 1104 is a conductive thin film, 1
Numeral 105 denotes an electron emitting portion formed by the energization forming process, and 1113 denotes a thin film formed by the energization activation process.

As the substrate 1101, for example, various glass substrates such as quartz glass and blue plate glass, various ceramic substrates such as alumina, or an insulating layer made of, for example, SiO 2 is laminated on the various substrates described above. Substrate or the like can be used. The device electrodes 1102 and 1103 provided on the substrate 1101 so as to be opposed to the substrate surface in parallel are formed of a conductive material. For example, Ni, Cr, Au, Mo, W, Pt, Ti, C
Materials are appropriately selected from metals such as u, Pd, Ag and the like, alloys of these metals, metal oxides such as In ₂ O ₃ -SnO ₂ , and semiconductors such as polysilicon. Can be used. To form the electrodes,
For example, it can be easily formed by using a combination of a film forming technique such as vacuum deposition and a patterning technique such as photolithography and etching. However, it may be formed by other methods (for example, printing technique).

The shapes of the device electrodes 1102 and 1103 are appropriately designed according to the application purpose of the electron-emitting device.
Generally, the electrode spacing L is usually designed by selecting an appropriate numerical value from the range of several hundreds of angstroms to several hundred micrometers, but among them, a preferable number for application to a display device is It is in the range of several tens of micrometer from the micrometer. Further, regarding the thickness d of the device electrode,
Usually, an appropriate numerical value is selected from the range of several hundred angstroms to several micrometers.

A fine particle film is used for the conductive thin film 1104. The fine particle film mentioned here is a film containing many fine particles as a constituent element (including an island-shaped aggregate).
I mean If you examine the microparticle film microscopically, usually
A structure in which the individual particles are spaced apart, a structure in which the particles are adjacent to each other, or a structure in which the particles overlap each other is observed.

The particle size of the fine particles used in the fine particle film is in the range of several Angstroms to several thousand Angstroms, but is more preferably in the range of 10 Angstroms to 200 Angstroms. belongs to. Further, the thickness of the fine particle film is appropriately set in consideration of various conditions described below. That is, the device electrode 11
02 or 1103, conditions necessary for good energization forming, which will be described later, and electric resistance of the fine particle film itself, which is required to have an appropriate value described later. Conditions, etc. In particular,
The setting is made in the range of several Angstroms to several thousand Angstroms, and the preferred one is between 10 Angstroms and 500 Angstroms.

Materials that can be used to form the fine particle film include, for example, Pd, Pt, Ru, Ag, Au, Ti, In, Cu,
Metals such as Cr, Fe, Zn, Sn, Ta, W, Pb, etc., and PdO,
Oxides such as SnO2, In2O3, PbO, Sb2O3,
Borides including HfB2, ZrB2, LaB6, CeB6, YB4, GdB4, etc., carbides including TiC, ZrC, HfC, TaC, SiC, WC, etc., and TiN, ZrN, HfN Semiconductors such as nitride, Si, Ge, etc., carbon,
And the like are appropriately selected from these.

As described above, the conductive thin film 1104 is formed of a fine particle film.
It was set to fall within the range of 10 3 to 10 7 [ohm / sq].

The conductive thin film 1104 and the device electrode 11
Since it is desirable that the wires 02 and 1103 be electrically connected well, they have a structure in which a part of each overlaps with the other. In the example of FIG. 7, the overlapping manner is such that the substrate, the device electrode, and the conductive thin film are stacked in this order from the bottom, but in some cases, the substrate, the conductive thin film, and the device electrode are stacked in this order from the bottom. I can't wait.

The electron emitting portion 1105 is a crack-like portion formed in a part of the conductive thin film 1104, and has an electrical property higher than that of the surrounding conductive thin film. The crack is formed by performing a later-described energization forming process on the conductive thin film 1104. Fine particles having a particle size of several Angstroms to several hundred Angstroms may be arranged in the crack. Since it is difficult to accurately and accurately show the actual position and shape of the electron-emitting portion, they are schematically shown in FIG. The thin film 1113 is a thin film made of carbon or a carbon compound.
The electron emission portion 1105 and its vicinity are covered. The thin film 1113 is formed by performing an energization activation process described later after the energization forming process.

The thin film 1113 is made of any one of single crystal graphite, polycrystalline graphite and amorphous carbon, or a mixture thereof, and has a thickness of 500 [Å] or less, but 300 [Å]. -Mm] or less. The actual thin film 1113
Since it is difficult to precisely illustrate the position and the shape of, they are schematically shown in FIG. In addition, in the plan view (a), an element in which a part of the thin film 1113 is removed is illustrated.

The basic structure of the preferred element has been described above. In the embodiment, the following element is used. That is, blue glass was used for the substrate 1101, and Ni thin films were used for the device electrodes 1102 and 1103. The thickness d of the device electrode was 1000 [angstrom], and the electrode interval L was 2 [micrometer].

Pd or P as the main material of the fine particle film
Using dO, the thickness of the fine particle film was set to about 100 [angstrom], and the width W was set to 100 [micrometer].

Next, a description will be given of a method of manufacturing a suitable planar surface conduction electron-emitting device. (A) to (d) of FIG.
Is a cross-sectional view for explaining a manufacturing process of the surface conduction electron-emitting device, and the notation of each member is the same as that in FIG.

(1) First, as shown in FIG. 8A, device electrodes 1102 and 1103 are formed on a substrate 1101. Before forming, the substrate 1101
Is thoroughly washed using a detergent, pure water, and an organic solvent, and then a material for an element electrode is deposited. (As a deposition method, for example, a vacuum film forming technique such as a vapor deposition method or a sputtering method may be used.) Then, the deposited electrode material is patterned using a photolithography-etching technique.
A pair of device electrodes (1102 and 1103) shown in FIG.
To form

(2) Next, a conductive thin film 1104 is formed as shown in FIG. In forming,
First, an organic metal solution is applied to the substrate (a), dried, heated and baked to form a fine particle film, and then patterned into a predetermined shape by photolithography and etching. Here, the organometallic solution is a solution of an organometallic compound whose main element is a material of fine particles used for the conductive thin film. (Specifically, in the present embodiment, Pd is used as a main element. In the embodiment, as a coating method,
Although the dipping method is used, other methods such as a spinner method and a spray method may be used. In addition, as a method of forming a conductive thin film formed of a fine particle film, other than the method of applying the organometallic solution used in the present embodiment, for example, a vacuum evaporation method, a sputtering method, a chemical vapor deposition method, or the like. May be used.

(3) Next, as shown in FIG. 10C, the forming power supply 1110 supplies the device electrodes 1102 and 1111 with each other.
The electron emitting portion 1105 is formed by applying an appropriate voltage during the period 03 and performing the energization forming process. Energizing form
Is a conductive thin film 110 made of a fine particle film.
4 is a process in which a current is applied to the electrode 4 to appropriately destroy, deform, or alter a part of the electrode 4 to change the structure to a structure suitable for emitting electrons. In a portion of the conductive thin film made of the fine particle film which has been changed to a structure suitable for emitting electrons (that is, the electron emitting portion 1105), an appropriate crack is formed in the thin film. Note that the electron emission unit 1105
As compared with before the formation, the electrical resistance measured between the device electrodes 1102 and 1103 greatly increases after the formation. In order to explain the energization method in more detail, FIG.
An example of an appropriate voltage waveform applied from the forming power supply 1110 is shown in FIG. When forming a conductive thin film made of a fine particle film, a pulse voltage is preferable. In the case of the present embodiment, a triangular wave pulse having a pulse width T1 is applied at a pulse interval T2 as shown in FIG. It was applied continuously. At that time, the peak value Vpf of the triangular wave pulse was sequentially increased. In addition, a monitor pulse Pm for monitoring the formation state of the electron emission portion 1105 is inserted between triangular wave pulses at appropriate intervals, and the current flowing at that time is measured by the ammeter 1.
It was measured at 111. In the embodiment, for example, 10
In a vacuum atmosphere of about -5 power [torr], for example, the pulse width T1 is 1 [millisecond], the pulse interval T2 is 10 [millisecond], and the peak value Vpf is 0.1 [V] for each pulse. The pressure was increased. Then, each time five pulses of the triangular wave are applied, the monitor pulse Pm is divided by one.
Was inserted. The monitor pulse voltage Vpm is set to 0.1 so as not to adversely affect the forming process.
[V] was set. Then, the device electrodes 1102 and 110
3 when the electric resistance becomes 1 × 10 6 ohms, that is, when the monitor pulse is applied, the ammeter 1111
When the current measured in step (1) became 1 × 10 −7 [A] or less, the energization related to the forming process was terminated.

The above method is a preferable method for the surface conduction electron-emitting device of the present embodiment. For example, the design of the surface conduction electron-emitting device such as the material and film thickness of the fine particle film or the element electrode interval L is changed. In such a case, it is desirable to appropriately change the energization conditions accordingly.

(4) Next, as shown in FIG.
The device electrodes 1102 and 1103 are supplied from the activation power source 1112.
During the energization activation process, apply an appropriate voltage during
Improve electron emission characteristics. The energization activation process refers to the electron emission portion 11 formed by the energization forming process.
This is a process of energizing under conditions 05 to deposit carbon or a carbon compound in the vicinity thereof. (In the figure, a deposit made of carbon or a carbon compound is schematically shown as a member 1113.) By performing the activation process, the emission current at the same applied voltage is typically smaller than that before the activation. Specifically, it can be increased by 100 times or more.

Specifically, 10 minus the fourth power to 1
By applying a voltage pulse periodically in a vacuum atmosphere within the range of 0 to the fifth power [torr], carbon or a carbon compound originating from an organic compound existing in the vacuum atmosphere is deposited. The deposit 1113 is any one of single crystal graphite, polycrystal graphite, and amorphous carbon, or a mixture thereof, and has a film thickness of 500.
[Angstrom] or less, more preferably 300 [angstrom] or less. In order to describe the energization method in more detail, FIG.
2 shows an example of an appropriate voltage waveform applied from Step 2. In the present embodiment, the energization activation process is performed by periodically applying a rectangular wave of a constant voltage.
ac was 14 [V], the pulse width T3 was 1 [millisecond], and the pulse interval T4 was 10 [millisecond]. Note that the above-described energization conditions are preferable conditions for the surface conduction electron-emitting device of the present embodiment, and when the design of the surface conduction electron-emitting device is changed, it is desirable to appropriately change the conditions accordingly.

An anode electrode 1114 shown in FIG. 8D is for capturing an emission current Ie emitted from the surface conduction electron-emitting device, and is connected to a DC high voltage power supply 1115 and an ammeter 1116. I have. (Note that the substrate 1101
When the activation process is performed after the display panel is incorporated in the display panel, the phosphor screen of the display panel is connected to the anode electrode 1114.
Used as While the voltage is applied from the activation power supply 1112, the emission current Ie is measured by the ammeter 1116 to monitor the progress of the energization activation process, and the activation power supply 11
12 is controlled. An example of the emission current Ie measured by the ammeter 1116 is shown in FIG. 10B. When the pulse voltage is started to be applied from the activation power supply 1112, the emission current Ie increases with the passage of time, but eventually saturates. And hardly increase. As described above, when the emission current Ie is substantially saturated, the application of the voltage from the activation power supply 1112 is stopped, and the energization activation process ends.

The above-mentioned energization conditions are preferable conditions for the surface conduction electron-emitting device of the present embodiment, and when the design of the surface conduction electron-emitting device is changed, the conditions should be changed accordingly. desirable.

As described above, the plane type surface conduction electron-emitting device shown in FIG. 8E was manufactured.

(Iii) Vertical type surface conduction electron-emitting device Next, another typical structure of a surface conduction electron-emitting device in which the electron-emitting portion or its periphery is formed of a fine particle film,
That is, the configuration of the vertical type surface conduction electron-emitting device will be described.

FIG. 11 is a schematic cross-sectional view for explaining the basic structure of a vertical type. In FIG.
202 and 1203 are device electrodes, 1206 is a step forming member, 1204 is a conductive thin film using a fine particle film, 1205
Are electron emitting portions formed by an energization forming process;
213 is a thin film formed by the activation process.
The difference between the vertical type and the flat type described above is that one of the element electrodes (1202) is provided on the step forming member 1206, and the conductive thin film 1204 is connected to the step forming member 1212.
06 is covered. Therefore, the element electrode interval L in the planar type shown in FIG. 7 is set as the step height Ls of the step forming member 1206 in the vertical type. The substrate 1201, the device electrodes 1202 and 12
03, the conductive thin film 1204 using the fine particle film, the materials listed in the description of the flat type can be similarly used. In addition, the step forming member 1206 includes:
For example, an electrically insulating material such as SiO2 is used.

Next, a method for manufacturing a vertical surface conduction electron-emitting device will be described. FIGS. 12A to 12F are cross-sectional views for explaining a manufacturing process.
Same as 1.

(1) First, as shown in FIG.
An element electrode 1203 is formed over a substrate 1201.

(2) Next, as shown in FIG. 9B, an insulating layer for forming a step forming member is laminated. The insulating layer may be formed by laminating, for example, SiO2 by a sputtering method. However, another film forming method such as a vacuum evaporation method or a printing method may be used.

(3) Next, as shown in FIG. 9C, an element electrode 1202 is formed on the insulating layer.

(4) Next, as shown in FIG. 9D, a part of the insulating layer is removed by using, for example, an etching method.
The device electrode 1203 is exposed.

(5) Next, as shown in FIG. 9E, a conductive thin film 1204 using a fine particle film is formed. For the formation, as in the case of the flat type, a film forming technique such as a coating method may be used.

(6) Next, as in the case of the flat type,
An energization forming process is performed to form an electron emission portion.
(A process similar to the planar energization forming process described with reference to FIG. 8C may be performed.) (7) Next, an energization activation process is performed as in the case of the planar type. Carbon or a carbon compound is deposited near the electron emitting portion. (A process similar to the planar energization activation process described with reference to FIG. 8D may be performed.) As described above, the vertical surface conduction electron-emitting device shown in FIG. Manufactured.

(Iv) Characteristics of the surface conduction electron-emitting device used in the display device The element structure and the manufacturing method of the planar and vertical surface conduction electron-emitting devices have been described above. The characteristics will be described.

FIG. 13 shows typical examples of (emission current Ie) versus (device applied voltage Vf) characteristics and (device current If) versus (device applied voltage Vf) characteristics of the device used in the display device. . Note that the emission current Ie is significantly smaller than the element current If, and it is difficult to show the same current on the same scale.
Since these characteristics are changed by changing design parameters such as the size and shape of the element, the two graphs are shown in arbitrary units.

The element used for the display device has the following three characteristics regarding the emission current Ie.

First, a certain voltage (this is referred to as a threshold voltage Vth
When a voltage of the above magnitude is applied to the element, the emission current Ie sharply increases. On the other hand, at a voltage lower than the threshold voltage Vth, the emission current Ie is hardly detected. That is, it is a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie.

Secondly, since the emission current Ie changes depending on the voltage Vf applied to the element, the emission current Ie varies with the voltage Vf.
The magnitude of e can be controlled.

Third, since the response speed of the current Ie emitted from the element is faster with respect to the voltage Vf applied to the element, the amount of charge of the electrons emitted from the element depends on the length of time during which the voltage Vf is applied. Can control.

Because of the above characteristics, the surface conduction electron-emitting device can be suitably used for a display device. For example, in a display device in which a large number of elements are provided corresponding to pixels of a display screen, if the first characteristic is used, display can be performed by sequentially scanning the display screen. That is,
The driving element has a threshold voltage Vt according to a desired light emission luminance.
h or higher, and a voltage lower than the threshold voltage Vth is applied to the non-selected elements. By sequentially switching the elements to be driven, the display screen can be sequentially scanned and displayed.

Further, since the emission luminance can be controlled by using the second characteristic or the third characteristic, gradation display can be performed.

(V) Structure of a multi-electron beam source in which a large number of elements are arranged in a simple matrix wiring. Next, a structure of a multi-electron beam source in which the above-mentioned surface conduction electron-emitting devices are arranged on a substrate and arranged in a simple matrix. Is described.

FIG. 2 is a plan view of the multi-electron beam source used for the display panel of FIG. On the substrate, surface conduction type emission elements similar to those shown in FIG. 7 are arranged, and these elements are wired in a simple matrix by row-direction wiring electrodes 1003 and column-direction wiring electrodes 1004. Row direction wiring electrode 1003 and column direction wiring electrode 1004
An insulating layer (not shown) is formed between the electrodes at the intersections of the two to maintain electrical insulation.

The multi-electron source having such a structure is as follows.
After previously forming a row direction wiring electrode 1003, a column direction wiring electrode 1004, an interelectrode insulating layer (not shown), and a device electrode and a conductive thin film of a surface conduction electron-emitting device on a substrate,
Row direction wiring electrode 1003 and column direction wiring electrode 1004
The device was manufactured by supplying power to each element through the device and performing an energization forming process and an energization activation process.

(3) Configuration of Driving Circuit and Driving Method Thereof FIG. 14 is a block diagram showing a schematic configuration of a driving circuit for performing television display based on an NTSC television signal. In the figure, a display panel 1701 corresponds to the above-described display panel, and is manufactured and operates as described above. The scanning circuit 1702 scans the display lines according to a previously specified order, and controls the control circuit 1.
Reference numeral 703 generates a signal to be input to the scanning circuit. The shift register 1704 shifts data for each line, and stores the frame memory a 1710 and the frame memory b 1711
Stores the data from the shift register 1704 for one screen for each line, and stores the data for one line in the modulation signal generator 1 in accordance with the scanning order specified in advance.
707.

The frame memory a 1710 and the frame memory b 1711 have the same function, and while one is inputting data from the shift register 1704 (input mode), the other outputs data to the modulation signal generator 1707 (output). mode).

The input mode and the output mode are switched by a simple switch circuit 1720, and the signal T output from the control circuit 1703 when one screen data is completed.
This is performed based on sw. Synchronous signal separation circuit 1706
Separates the synchronization signal from the NTSC signal.

Hereinafter, the function of each unit of the apparatus shown in FIG. 14 will be described in detail.

First, the display panel 1701 includes terminals Dx1 to Dxm and terminals Dy1 to Dyn, and a high voltage terminal Hv.
Connected to an external electric circuit via this house,
The terminals Dx1 to Dxm are connected to a multi-electron beam source provided in the display panel 1701, that is, cold cathode devices arranged in a matrix of m rows and n columns in a matrix of one row (n elements) in a predetermined order. Therefore, scanning signals for sequentially driving are applied. On the other hand, to the terminals Dy1 to Dyn, a modulation signal for controlling the output electron beams of the n elements for one row selected by the scanning signal is applied. A DC voltage source V is connected to the high voltage terminal Hv.
a supplies a DC voltage of, for example, 5 kV, which is an accelerating voltage for applying sufficient energy to the electron beam output from the multi-electron beam source to excite the phosphor.

Next, the scanning circuit 1702 will be described. This circuit has m switching elements inside (in the figure,
S1 to Sm), each switching element selects either the output voltage of the DC voltage source Vx or 0 [V] (ground level), and the switching element of the display panel 1701 It is electrically connected to terminals Dx1 to Dxm. Each of the switching elements S1 to Sm is provided with a control signal Tsc output from the control circuit 1703.
It works based on an, but in fact, for example, FE
It can be easily configured by combining switching elements such as T. The DC voltage source V
x is set to output a constant voltage so that the drive voltage applied to the element that is not scanned based on the characteristics of the electron-emitting device illustrated in FIG. 13 is equal to or lower than the electron emission threshold voltage Vth. .

The switch circuit 1720 has n
Frame elements a171
0 or n frame memories b1711 are simultaneously switched so that either one is in the input mode and the other is in the output mode.

The control circuit 1703 has a function of coordinating the operation of each unit so that an appropriate display is performed based on an image signal input from the outside. Based on a synchronizing signal Tsync sent from a synchronizing signal separating circuit 1706, which will be described below, control signals Tscan, Tsft, Tmryo, Tmryi, and Tsw are generated for each unit.

The control circuit 1703 controls the scanning circuit 1702 so that the scanning is performed in the order specified in advance.
And the frame memory a 1710 and the frame memory b 1711 are controlled. The synchronizing signal separating circuit 1706 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC system television signal input from the outside. As is well known, a frequency separating (filter) circuit is used. It can be easily configured. Synchronous signal separation circuit 1
The synchronization signal separated by 706 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 D for convenience.
This signal is referred to as an ATA signal.
Is input to

Further, a shift register 1704 is for serially / parallel-converting the DATA signal input serially in time series for each line of an image, and a control signal Tsft sent from the control circuit 1703.
Operate based on That is, the control signal Tsft can be rephrased as a shift clock of the shift register 1704. The data for one line of the image that has been subjected to the serial / parallel conversion (corresponding to the drive data for n electron-emitting devices) is output from the shift register 1704 as n signals Id1 to Idn.

A frame memory a 1710 and a frame memory b 1711 are storage devices for storing data for one screen of an image for a required time only.
3, the contents of Id1 to Idn are stored for each line as appropriate in accordance with the control signal Tmryi sent from 3. The stored contents are read out by the control signal Tmryo in the line order set in the control circuit 1703 in advance, output as I'd1 to I'dn, and input to the modulation signal generator 1707. Tmryi and Tmryo are switched to a frame memory of a corresponding mode by a switch (not shown) by a control signal Tsw.

The modulation signal generator 1707 controls the electron-emitting device 10 according to each of the image data I'd1 to I'dn.
15 is a signal source for appropriately driving and modulating each of the display panels 15, and the output signal thereof is supplied to the display panel 17 through terminals Dy 1 to Dyn.
01 is applied to the electron-emitting device 1015.

As described with reference to FIG. 13, the surface conduction electron-emitting device according to the present invention has the following basic characteristics with respect to the emission current Ie. That is, electron emission has a clear threshold voltage Vth (8 [V] in a surface conduction electron-emitting device of an embodiment described later), and electron emission occurs only when a voltage equal to or higher than the threshold Vth is applied. For a voltage equal to or higher than the electron emission threshold Vth, the emission current Ie also changes according to the change in the voltage as shown in the graph of FIG. For this reason, when a pulse-like voltage is applied to the device, for example, when a voltage equal to or lower than the electron emission threshold Vth is applied, no electron emission occurs. An electron beam is output from the conduction type emission device. At this time, the intensity of the output electron beam can be controlled by changing the pulse peak value Vm.

Further, 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 performing the voltage modulation method, a circuit of the 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 1707. be able to. When implementing the pulse width modulation method, the modulation signal generator 1707 generates a voltage pulse having a constant peak value and modulates the width of the voltage pulse appropriately according to input data. Circuit can be used.

The shift register 1704, the frame memory a1710, and the frame memory b1711 can be of a digital signal type or an analog signal type. That is, the serial / parallel conversion and storage of the image signal may be performed at a predetermined speed.

When the digital signal type is used, the output signal DATA of the synchronization signal separation circuit 1706 needs to be converted into a digital signal.
An A / D converter may be provided at the output unit 6. In this connection, the frame memory a 1710 and the frame memory b
The circuit used for the modulation signal generator differs slightly depending on whether the output signal of 171 is a digital signal or an analog signal. That is, in the case of the voltage modulation method using a digital signal, the modulation signal generator 1707 includes, for example, 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, a modulation signal generator 1707
Include, for example, a high-speed oscillator, a counter (counter) for counting the number of waves output from the oscillator, and a comparator (comparator) for comparing the output value of the counter with the output value of the memory.
Is used. If necessary, an amplifier for amplifying the pulse width modulated signal output from the comparator to the drive voltage of the electron-emitting device can be added.

In the case of the voltage modulation method using an analog signal, an amplification circuit using, for example, an operational amplifier can be used as the modulation signal generator 1707, and a shift level circuit and the like can be added as necessary. In the case of the pulse width modulation method, for example, a voltage controlled oscillator (VCO)
And, if necessary, an amplifier for amplifying the voltage up to the drive voltage of the electron-emitting device can be added.

In the image forming apparatus to which the present invention can be applied, an electron emission element is applied by applying a voltage to each of the electron emission elements via terminals Dx1 to Dxm and Dy1 to Dyn outside the container. Occurs. Metal back 1019 or transparent electrode (not shown) via high voltage terminal Hv
To apply a high voltage to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 1018 and emit light to form an image.

The configuration of the image forming apparatus described here is an example of an image forming apparatus to which the present invention can be applied, and various modifications can be made based on the concept of the present invention. The input signal is described in the NTSC system. However, the input signal is not limited to the NTSC system, but may be a PAL or SECAM system or a TV signal (MUSE system or other high-definition TV) system including a larger number of scanning lines. The present invention can also be applied to non-interlaced monitor signals for digital computers.

[0122]

Embodiments of the present invention will be described below in detail with reference to the drawings. In each of the embodiments described below, as the multi-electron beam source, N × M (N = 1536, M = 512) surface conduction type of the above-described type having an electron emission portion in the conductive fine particle film between the electrodes. A multi-electron beam source was used in which the emission elements were arranged in a matrix with M row-directional wirings and N column-directional wirings (see FIGS. 1 and 2). The method of manufacturing the image forming apparatus and the specific method of displaying an image are as described above. Here, only the scanning order will be described.

Example 1 For convenience of explanation, as shown in FIG. 15, a display device having 21 scanning lines (M = 21) and three spacers is used. Each scanning line is Dx1 to Dx21 from above, and the spacers are Sp1 to S from above.
Let's call it p3. In FIG. 15, Sp1,
Sp2 stands on Dx11 and Sp3 stands on Dx18.

When an image is displayed on this device, the scanning frequency is 60 Hz in this embodiment.
Within one frame time (1/60 second) corresponding to Dx1
To Dx21 are each driven once for display. Hereinafter, the order of the driving in this embodiment will be described.

First, the image display area is set to 3 which is the number of spacers.
Into two large areas. Each region is arranged with a spacer at the center, and Dx1 to Dx7 are replaced by large region 1, Dx8 to
Dx14 is a large area 2 and Dx15 to Dx21 are a large area 3.

Then, scanning is performed in the order of each area, in ascending numerical order within the area. That is, the first line of the large area 1 is driven, then the first line of the large area 2, the first line of the large area 3, and then the second line of the large area 1.

In this embodiment, Dx1, 8, 15, 2, 9, 16... Every (1/60) / 21 seconds. . . . . 7, 14,
21 and the end of one frame after 1/60 second, Dx
Returning to step 1 and scanning sequentially (see FIG. 15).

More specifically, referring to FIG. 14, the image data (DATA) is input to the shift register 1704, and is serially / parallel converted for each line of the image by the TSFT signal, and is in the first input mode. It is sent to the frame memory a1710, and 1 according to the Tmryi signal.
Store data for the line. This is repeated one after another, and the frame memory a1710 stores the data of the first image for each line in 1/60 second. During this time, there is no data yet in the frame memory b1711 in the output mode.
No image is displayed.

Next, the switch circuit 17 is activated by the Tsw signal.
Reference numeral 20 switches the frame memory a 1710 to the output mode and the frame memory b 1711 to the input mode. Next, the frame memory a1710 in the output mode stores T
According to the mryo signal, the data of the first line, which is the first drive line set in advance, is sent to the modulation signal generator 1707, and at the same time, the scanning circuit 1702
Select the first line based on an. Such operations are performed on Dx1, 8, 15,. . . . . The desired lines are displayed one after another, and one image is drawn in 1/60 second. During this time, the frame memory b1711 in the input mode
Stores the data for the next one image as described above.

Next, the switch circuit 17 is activated by the Tsw signal.
Reference numeral 20 switches the frame memory b 1711 to the output mode and the frame memory a 1710 to the input mode, and similarly displays the second image. This is repeated to display an image.

According to this scanning order, it is not necessary to continuously drive the vicinity of the spacer, and the charging relaxation time of the spacer can be greatly increased as compared with the case of driving in the order of Dx1 to Dx21.

That is, the driving in the large area 1 is controlled by the Sp
Assuming that it is related to the charging of No. 1, the charging relaxation time can have a margin of three times. Here, the charge relaxation time refers to a time until the charge amount of the spacer is reduced to a level that does not affect the electron trajectory.

Although this embodiment has been described with reference to a panel including 21 lines and 3 spacers for convenience, even if the panel is enlarged and the number of scanning lines and spacers is increased, the charging relaxation time can be extended by this driving method. N × M (N = 1
536, M = 512), the driving method according to the present invention was applied to a structure in which eight spacers were erected and the driving method according to the present invention was applied to a large area group in which 64 lines (512/8 =) were divided into eight areas. An image similar to that of the driving method could be obtained, and even if the amount of emitted electrons was larger than that of the conventional method, a high-brightness good image forming apparatus without beam bending and discharge could be obtained.

It is to be noted that all the scanning lines are not necessarily included in each of the above-mentioned regions, and it is sufficient that the above-described regions include a scanning line which has an influence on the spacer charging. In that case, scanning lines not included in the area may be scanned at any time. (For example, scan first collectively and then scan each area.) We have experimentally confirmed that an element separated from the spacer by a few lines has almost no effect on spacer charging, and the present invention It is clear that the present invention is effective even if the number of scanning lines increases and the number of scanning lines is not a multiple of the number of spacers.

(Embodiment 2) The scanning order of the second embodiment of the present invention will be described using a panel of 21 lines and 3 spacers similar to that of Embodiment 1 (see FIG. 16). Other scanning and the like are the same as in the first embodiment.

The image area is divided into three parts, and driving is performed in the order of each area as in the first embodiment. However, in the second embodiment, the driving order in the area is different from that in the first embodiment. Taking large area 1 as an example,
The order of driving in the area will be described below.

The driving method according to the present embodiment further includes
Dx3 which has a large effect on spacer charging especially near the spacer
To Dx5 (small area 1) and Dx1 and Dx with little effect
2, Dx6 and Dx7 (small area 2) are selected so that the lines of the small area 1 group, which has a large influence on the spacer charging, are not continuous. That is, in the large area 1, Dx3 (small area 1), Dx1 (small area 2), Dx4 (small area 1), Dx2 (small area 2),
Select Dx5 (small area 1), Dx6 (small area 2), Dx7 (small area 2), and return to Dx3 (small area 1).

As a whole, as shown in FIG.
3, 10, 17, 1, 8, 15. . . . . 7, 14, 2
1 and the end of one frame after 1/60 second.
Return to x3 and repeat. According to this scanning order, the interval for driving the line which greatly affects the spacer charging in the vicinity of the spacer is further increased, and the charging relaxation time of the spacer can be further increased as compared with the first embodiment.

By the driving according to the present embodiment, it was possible to obtain a high-brightness and good image forming apparatus without beam bending and discharge.

The method of dividing the small areas and the order of selecting the small areas are not limited to the above, and may be determined as appropriate based on the amount of emitted electrons, the spacer charging relaxation time, and the like.

It is clear that this embodiment is effective even if the number of scanning lines is further increased and the number of scanning lines is not a multiple of the number of spacers.

Further, in this embodiment, the example in which the spacers are arranged in the row direction is shown to clarify the scanning order. However, the horizontal width of the spacers on the screen is arranged so as to fill the horizontal line of the screen or the center. Although the division into regions may be taken into consideration depending on whether or not they are arranged only in the portion, it can be determined in consideration of the material strength of the face plate and the rear plate, the degree of vacuum, the inch size of the screen, and the like. Also,
When the spacers are arranged only in the central portion, it is also possible to perform scanning by dividing the area only around the central portion in one line scanning period. In general, one screen is displayed by sequentially scanning horizontal lines, so the scanning example shown in the above embodiment is appropriate.

[0143]

As described above, with the image forming apparatus of the present invention, even when the amount of emitted electrons is increased, it is possible to display a high-brightness good image without a beam trajectory shift or discharge due to spacer charging. It became.

In particular, since the scanning around the spacer is divided into a large area and a small area so as to prevent the deflection of the electron beam due to the charging of the spacer, the present image forming apparatus can exhibit its maximum performance. .

[Brief description of the drawings]

FIG. 1 is a perspective view of an image forming apparatus according to an embodiment of the present invention, in which a part of a display panel is cut away.

FIG. 2 shows a multi-electron beam used in an embodiment according to the present invention.
FIG. 3 is a plan view of a substrate of a memory source.

FIG. 3 shows a multi-electron beam used in an embodiment according to the present invention.
FIG. 3 is a partial cross-sectional view of a substrate of a memory source.

FIG. 4 is a plan view illustrating a phosphor array of a face plate of a display panel according to the present invention.

FIG. 5 is a view for explaining another configuration example of the phosphor according to the present invention.

FIG. 6 is an AA ′ diagram of a display panel according to an embodiment of the present invention.
It is sectional drawing.

FIGS. 7A and 7B are a plan view and a cross-sectional view, respectively, of a planar surface conduction electron-emitting device used in an embodiment according to the present invention.

FIG. 8 is a cross-sectional view illustrating a manufacturing process of the planar surface-conduction emission type emission device according to the present invention.

FIG. 9 is an applied voltage waveform at the time of energization forming processing according to the present invention.

FIG. 10 is a diagram showing a change in an applied voltage waveform (a) and an emission current Ie (b) in the activation process according to the present invention.

FIG. 11 is a sectional view of a vertical surface conduction electron-emitting device used in an embodiment according to the present invention.

FIG. 12 is a sectional view illustrating a manufacturing process of a vertical surface conduction electron-emitting device according to the present invention.

FIG. 13 is a graph showing typical characteristics of a surface conduction electron-emitting device used in an embodiment according to the present invention.

FIG. 14 is a block diagram illustrating a schematic configuration of a drive circuit of the image forming apparatus according to the embodiment of the present invention.

FIG. 15 is a diagram illustrating a driving order according to the first embodiment of the present invention.

FIG. 16 is a diagram illustrating a driving order according to the second embodiment of the present invention.

FIG. 17 is an example of a conventionally known surface conduction electron-emitting device.

FIG. 18 is an example of a conventionally known FE element.

FIG. 19 is an example of a conventionally known MIM type element.

FIG. 20 is a perspective view of the display panel of the image forming apparatus with a part cut away.

[Explanation of symbols]

 1010 Black conductive material 1011 Substrate 1012 Electron emitting element 1013 X direction electrode 1014 Y direction electrode 1015 Rear plate 1016 Support frame 1017 Face plate 1018 Fluorescent film 1019 Metal back 1105 Electron emitting section

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 5/66 H04N 5/66 B

Claims (26)

[Claims] 1. An electron source in which a plurality of electron-emitting devices are arranged; a phosphor which emits light by irradiation of an electron beam emitted from the electron source; and a phosphor arranged between the electron source and the phosphor. And a driving method of the image forming apparatus having a plurality of spacers, wherein the driving order of the plurality of electron-emitting devices is skipped so that an electron beam is not continuously irradiated on the phosphor in the vicinity of the spacer. For driving an image forming apparatus. 2. Skipping the order of driving the electron-emitting devices means dividing the plurality of electron-emitting devices into a plurality of groups each including an electron-emitting device group near each spacer, and The electron-emitting devices are divided into a plurality of sub-groups, and during one unit period, only the electron-emitting devices of any one of the selected one sub-groups are driven. The driving method according to claim 1, wherein the switching is performed sequentially. 3. The step of dividing the electron-emitting devices in each group into a plurality of sub-groups includes dividing the plurality of electron-emitting devices in the group into a plurality of sub-groups according to a distance from the spacer. The driving method according to claim 1 or 2, wherein: 4. The method according to claim 1, wherein during the one unit period, driving only the electron-emitting devices of an arbitrary one sub-group in the selected one group includes the step of driving the sub-group to be driven each time the group is selected. The driving method according to claim 2, wherein the switching is performed. 5. The method according to claim 4, wherein switching the sub-group to be driven every time the group is selected means that the sub-group is sequentially switched in accordance with a spatial arrangement order. A method for driving an image forming apparatus. 6. Switching the sub-group to be driven each time the group is selected means that the sub-group which is farther from the spacer and which is closer to the spacer in a spatial arrangement are alternately driven. The driving method according to claim 4, wherein the switching is performed in such a manner as described above. 7. An electron source in which a plurality of electron-emitting devices are arranged; a phosphor which emits light by irradiation of an electron beam emitted from the electron source; and a phosphor arranged between the electron source and the phosphor. In the image forming method in an image forming apparatus having a plurality of spacers, the position of irradiating the phosphor with the electron beam is set to be one unit period so that the phosphor in the region near the spacer is not continuously irradiated with the electron beam. An image forming method for an image forming apparatus, wherein spatial skipping is performed for each image. 8. The step of spatially skipping the position of irradiating the electron beam every one unit period means that the phosphor is divided into a plurality of large regions each having a region near each spacer as one region. The area is divided into a plurality of small areas, and during one unit period, the electron beam is applied only to the pixels of any one small area in the selected one large area, and the pixel is selected for each one unit period. The image forming method according to claim 7, wherein the large area is sequentially switched. 9. Dividing each large area into a plurality of small areas means dividing a plurality of pixel groups in the large area into a plurality of small areas according to a distance from the spacer. The image forming method according to claim 8, wherein 10. The method of irradiating only one pixel of an arbitrary small area in a selected one large area during the one unit period with an electron beam means that a small area is selected every time the large area is selected. 9. The image forming method according to claim 8, wherein the image forming method is switched. 11. The image forming apparatus according to claim 10, wherein switching the small area every time the large area is selected means that the small area is sequentially switched in accordance with a spatial arrangement order. How to drive the device. 12. Switching the small area each time the large area is selected means that the electron beam is alternately applied to the small area that is far from the spacer and close to the small area in a spatial arrangement. The image forming method according to claim 10, wherein switching is performed so that irradiation is performed. 13. An electron source in which a plurality of electron-emitting devices are arranged, a phosphor that emits light by irradiation of an electron beam emitted from the electron source, and a phosphor disposed between the electron source and the phosphor. A plurality of spacers, wherein the driving means for driving the plurality of electron-emitting devices in a different order than the order of driving the plurality of electron-emitting devices so that the phosphor near the spacer is not continuously irradiated with the electron beam. An image forming apparatus comprising: 14. A group selection unit that divides the plurality of electron-emitting devices into a plurality of groups each including an electron-emitting device group near each spacer, and sequentially selects a group for each unit period. Means, and dividing the electron-emitting devices in each group into a plurality of sub-groups.
14. The image forming apparatus according to claim 13, further comprising: a sub-group driving unit that drives only one electron-emitting device of an arbitrary sub-group in the group selected by the selecting unit during a unit period. apparatus. 15. The image according to claim 14, wherein the plurality of subgroups are a plurality of subgroups obtained by dividing a plurality of electron-emitting devices in the group according to a distance from the spacer. Forming equipment. 16. The driving method according to claim 14, wherein the sub-group driving unit is a unit that switches the sub-group to be driven each time the group is selected. 17. The method according to claim 16, wherein the sub-group driving unit is a unit that sequentially switches and drives the sub-groups according to a spatial arrangement order. 18. The sub-group driving unit according to claim 16, wherein the sub-group driving unit is a unit that alternately drives the sub-group far from the spacer and the sub-group close to the spacer in a spatial arrangement. Image forming apparatus. 19. The driving unit stores at least two frame memories for storing image data for one screen and outputting the image data in an arbitrary order, one of the frame memories for reading, and the other for reading for each screen. The image forming apparatus according to claim 13, further comprising a switch for switching. 20. The electron source has a plurality of electron-emitting devices connected by wiring, the spacer has a semiconductive film on the surface, and the semiconductive film on the surface is the wiring. The image forming apparatus according to claim 13, wherein the image forming apparatus is electrically connected to the phosphor. 21. The electron source has a plurality of electron-emitting devices connected by wiring, and the spacer is disposed between the wiring and the phosphor such that a longitudinal direction is parallel to the wiring. 21. The image forming apparatus according to claim 20, wherein the spacer is a rectangular spacer arranged, and a semiconductive film on a surface of the spacer is electrically connected to the wiring and the phosphor. 22. The electron source has a plurality of electron-emitting devices arranged in a matrix with a plurality of row-direction wirings and a plurality of column-direction wirings, and the semiconductive film on the surface of the spacer includes the row-direction wiring. 21. The image forming apparatus according to claim 20, wherein the image forming apparatus is electrically connected to the column wiring and the phosphor. 23. The electron source includes a plurality of electron-emitting devices arranged in a matrix with a plurality of row-direction wirings and a plurality of column-direction wirings, and the spacer is a rectangular spacer, and has a longitudinal direction. The phosphor is disposed between the row-direction wiring or the column-direction wiring and the phosphor such that the row-direction wiring or the column-direction wiring is parallel to the phosphor. 21. The image forming apparatus according to claim 20, wherein a wiring or a column direction wiring is electrically connected to the phosphor. 24. The image forming apparatus according to claim 13, wherein said electron-emitting device is a cold cathode device. 25. The electron-emitting device according to claim 13, wherein the electron-emitting device is a cold negative electron-emitting device having a conductive film including an electron-emitting portion between electrodes to which current is applied.
The image forming apparatus according to claim 1. 26. The image forming apparatus according to claim 24, wherein the electron emission device is a surface conduction type emission device.