JPH09134147A - Multi-electron beam source and display device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an element from generating ringing at the time of synchronizing with a rising edge of a pulse and being destroyed when a picture signal is pulse-width-modulated and is impressed on a cold cathode. SOLUTION: When a NTSC picture signal is inputted, the signal is digitized by an 8-bit A/D converter 105, and (m)×(n) picture elements for one line of the panel are inputted to a D/A converter in a modulation signal generator 108. On the other hand, a n-bit shift register 1083 in the modulation signal generator 108 shifts a rectangular pulse by a clock cycle short enough at the cycle for one horizontal scanning period and outputs (n) pieces of pulses. This output performs switching of the output signal of the D/A converter and modulated signal with a deviated rise time and a prescribed width is impressed on the element. The modulated signal thus obtained rises up at a timing according to the picture element value and falls in synchronization with each line. Consequently, the generation of ringing can be prevented at rising up and its harmful effect can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive signal, which causes a problem when an image is displayed by an image display device in which a plurality of electron beam sources composed of cold cathode elements are arranged on a two-dimensional plane. The present invention relates to a method of reducing noise mixed in the.

[0002]

2. Description of the Related Art Conventionally, two types of electron-emitting devices are known, a hot cathode device and a cold cathode device. Among these, among the cold cathode devices, for example, a surface conduction type emission device, a field emission type device (hereinafter referred to as FE type), a metal / insulating layer / metal type emission device (hereinafter referred to as MIM type), and the like are known. I have.

[0003] As a surface conduction type emission element, for example,
MIElinson, Radio Eng. ElectronPhys., 10,1290, (196
5) and other examples described later are known.

The surface conduction electron-emitting device utilizes a phenomenon in which an electron is emitted when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. As this surface conduction type emission element, Sn described by Elinson et al.
In addition to those using O2 thin films, those using Au thin films [GD
ittmer: "Thin Solid Films", 9,317 (1972)] and In2O3
/ SnO2 thin film [M. Hartwell and CGFonst
ad: "IEEE Trans. EDConf.", 519 (1975)] and those using carbon thin films [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1,
22 (1983)].

As a typical example of the device configuration of these surface conduction type electron-emitting devices, FIG. Hartwel
1 shows a plan view of an element according to the present invention. In FIG.
Reference numeral 1 denotes a substrate, and reference numeral 3004 denotes a conductive thin film made of a metal oxide formed by sputtering. The conductive thin film 3004 is formed in an H-shaped planar shape as shown. An electron emission portion 3005 is formed by performing an energization process called energization forming described later on the conductive thin film 3004. The interval L in the figure is 0.5 to 1 [mm], and W is
It is set at 0.1 [mm]. In addition, 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, and the position and shape of the actual electron emitting portion are faithfully represented. Not necessarily.

[0006] M. In the above-described surface conduction electron-emitting device including the device by Hartwell et al., The electron-emitting portion 3005 is formed by subjecting the conductive thin film 3004 to an energization process called energization forming before electron emission.
It was common to form That is, the energization forming energizes by applying a constant DC voltage or a DC voltage boosting at a very slow rate of, for example, about 1 V / min to both ends of the conductive thin film 3004,
The electron emitting portion 30 in a state where the conductive thin film 3004 is locally destroyed, deformed or deteriorated, and is in an electrically high resistance state.
05 is formed. Note that a part of the conductive thin film 3004 that has been locally broken, deformed, or altered includes
Cracks occur. When an appropriate voltage is applied to the conductive thin film 3004 after the energization forming, electron emission is performed in the vicinity of the crack.

An example of the FE type is, for example, WPDyke
& W.W.Dolan, "Field emission", Advance in Electron P
hysics, 8,89 (1956) or CASpindt, "Physica
lproperties of thin-film field emission cathodes w
ith molybdenium cones ", J.Appl.Phys., 47,5248 (1976)
Etc. are known.

As a typical example of the FE type element structure, FIG. A. 1 shows a cross-sectional view of a device by Spindt et al. In the figure, reference numeral 3010 denotes a substrate, and 3011
Is an emitter wiring made of a conductive material, 3012 is an emitter cone, 3013 is an insulating layer, and 3014 is a gate electrode. This device comprises an emitter cone 3012 and a gate electrode 3
By applying an appropriate voltage during 014, field emission is caused from the tip of the emitter cone 3012.

As another element structure of the FE type, as shown in FIG.
There is also an example in which an emitter and a gate electrode are arranged on a substrate almost in parallel with the plane of the substrate, instead of a laminated structure like 0.

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. MIM
FIG. 21 shows a typical example of the element structure of the mold. This figure is a cross-sectional view. In the figure, 3020 is a substrate, 3021 is a lower electrode made of metal, 3022 is a thin insulating layer having a thickness of about 100 Å, and 3023 is a thickness of 80 to 300.
The upper electrode is made of a metal having a thickness of about Å. M
In the IM type, by applying an appropriate voltage between the upper electrode 3023 and the lower electrode 3021, the upper electrode 3023
The electron emission is caused from the surface of.

The above-mentioned cold cathode device can obtain electrons at a lower temperature than the hot cathode device, and therefore does not require a heater for heating. 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. In addition, the response speed is slow because the hot cathode element operates by heating the heater, and the cold cathode element has an advantage that the response speed is fast.

For this reason, research for applying the cold cathode device 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 because it has a particularly simple structure and is easy to manufacture among the cold cathode devices. Therefore, for example, Japanese Patent Application Laid-Open No.
Methods for arranging and driving a large number of devices have been investigated, as disclosed at 332.

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.

In particular, as an application to an image display device, for example, as disclosed in US Pat. No. 5,066,883, JP-A-2-257551 and JP-A-4-28137 by the present applicant, a surface-conduction emission device is used. An image display device using a combination of a phosphor that emits light by irradiation with an electron beam has been studied. An image display device using a combination of a surface conduction electron-emitting device and a phosphor is expected to have better characteristics than other conventional image display devices. 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 is disclosed in US Pat. No. 4,904,89 by the present applicant.
5 is disclosed. Further, as an example in which the FE type is applied to an image display device, for example, R.F. A flat panel display device reported by Meyer et al. Is known [R. Meyer: "Rece
nt Development on Microtips Display at LETI ", Tech.
Digest of 4th Int. Vacuum Microelectronics Conf.,
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.
55738.

The inventors have tried cold cathode devices of various materials, manufacturing methods and structures, including those described in the above-mentioned prior art. Furthermore, research has been conducted on a multi-electron beam source in which a large number of cold cathode devices are arranged, and on an image display device using the multi-electron beam source.

The inventors have tried a multi-electron beam source by an electrical wiring method shown in FIG. 22, for example. That is, it is a multi-electron beam source in which a large number of cold cathode devices are two-dimensionally arranged and these devices are wired in a matrix as shown.

In the figure, 4001 schematically shows a cold cathode element, 4002 shows a wiring in a row direction, and 4003 shows a wiring in a column direction. Row direction wiring 4002 and column direction wiring 400
3 actually has a finite electric resistance,
In the drawing, they are shown as wiring resistances 4004 and 4005. The above-described wiring method is called simple matrix wiring.

Although a 6 × 6 matrix is shown for convenience of illustration, the scale of the matrix is not limited to this. For example, in the case of a multi-electron beam source for an image display device, a desired image display is performed. It arranges and wires the elements enough to carry out.

In a multi-electron beam source in which cold cathode devices are arranged in a simple matrix, a row-direction wiring 4002 and a column-direction wiring 400 are used to output a desired electron beam.
3 is applied with an appropriate electric signal. For example, to drive one row of the cold cathode devices in the matrix, a selection voltage Vs is applied to the row direction wiring 4002 of the selected row,
At the same time, the non-selection voltage Vns is applied to the row direction wiring 4002 of the non-selected row. In synchronization with this, column direction wiring 4003
A drive voltage Ve for outputting an electron beam is applied to. According to this method, wiring resistances 4004 and 4004
If the voltage drop due to 5 is ignored, the voltage of Ve-Vs is applied to the cold cathode elements of the selected row, and the voltage of Ve-Vns is applied to the cold cathode elements of the non-selected rows. V
If e, Vs, and Vns are set to voltages of appropriate magnitudes, an electron beam of a desired intensity should be output only from the cold cathode elements in the selected row, and a different drive voltage Ve is applied to each of the column wirings. If applied, each of the elements in the selected row should output a different intensity electron beam. Further, if the length of time during which the drive voltage Ve is applied is changed, the length of time during which the electron beam is output should be changed.

Therefore, the multi-electron beam source in which the cold cathode elements are wired in a simple matrix has various applications. For example, if an electric signal according to image information is appropriately applied, it is suitable as an electron source for an image display device. Can be used.

When manufacturing a surface conduction electron beam source, a process called energization activation is performed after the forming process in order to improve the characteristics of each electron-emitting device. This process is a process of depositing carbon or a carbon compound on the electron emitting portion formed by forming.

After the activation by energization, for the purpose of stabilizing the electron emission characteristics of the surface conduction electron-emitting device, carbon or a carbon compound is newly deposited in the electron emitting portion or in the vicinity thereof even if the surface conduction electron emitting device is energized. To avoid this, it is necessary to reduce the partial pressure of the organic gas in the vacuum atmosphere around the surface conduction electron-emitting device and maintain this state.

Specifically, it is preferable to reduce the partial pressure of the organic gas in the atmosphere to 10 −8 [torr] or less and maintain it, and if possible, 10 −10.
It is desirable to keep the power [torr] or less. The partial pressure of the organic gas means that carbon and hydrogen are the main components and the mass number is 1
It refers to one obtained by integrating partial pressures of organic molecules in the range of 0 to 200, and is quantitatively measured using a mass spectrometer.

As a typical method for reducing the partial pressure of the organic gas in the surrounding environment of the surface-conduction type emission device, a vacuum container containing a substrate on which the surface-conduction type emission device is formed is heated so that each member surface in the container is heated. There is a method of performing vacuum evacuation using a vacuum pump that does not use oil, such as a solution pump or an ion pump, while desorbing the adsorbed organic gas molecules.

After the partial pressure of the organic gas is reduced in this way, the state can be maintained by using a vacuum pump that does not use oil and continuing exhaustion thereafter. However, the method of providing a vacuum pump and constantly evacuating may be disadvantageous in terms of capacity, power consumption, weight, price, etc., depending on the application purpose. Therefore, for example, when the surface conduction electron-emitting device is applied to an image display device, the getter film is formed in the vacuum container after the organic gas molecules are sufficiently desorbed to reduce the partial pressure of the organic gas. The exhaust pipe is sealed to maintain the state.

By carrying out such a treatment, it is possible to prevent the deposition of new carbon or a carbon compound due to aging or energization on the surface conduction type element after the energization activation treatment, so that the electron emission characteristics can be stabilized. You can

[0030]

However, in the multi-electron beam source in which the cold cathode elements as described above are wired in a simple matrix, the following problems actually occur. The signal applied to the row-direction wiring is called a scanning signal, and the signal applied to the column-direction wiring is called a modulation signal.

The present invention is based on the fact that the intensity of the electron beam is changed by changing the amplitude of the above-mentioned drive voltage Ve to display an image. FIG. 24 is a time chart for explaining a scanning signal and a modulation signal in the conventional amplitude modulation driving method.

As shown in FIG. 24, in the period K, the surface conduction electron-emitting device in the i-th row in FIG. 23 is driven, and in the period K + 1, i
The surface conduction electron-emitting device of the + 1th row is driven, and the surface conduction electron emission device of the i + 2th row is driven in the period K + 2, and the scanning signal is applied to the row direction wiring and the modulation signal is applied to the column direction wiring. As the modulation signal, as shown in FIG. 24, pulses having different rising amplitudes are applied, and the amplitude of the pulse is manipulated in accordance with the image signal to display an image.

However, the conventional driving device can output a rectangular wave with no ringing as shown in FIG. 24 in the no-load state, but in the case of actually driving the multi-electron source as a load, FIG. As shown in, a large ringing occurred at the rising edge of the waveform. The inventor suspects that the cause of this is not the multi-electron source itself, but the inductive component of a large number of cables connecting the driving device and the multi-electron source and the capacitive component between them. Is thinking. The inventors have confirmed that this is because the rising edges of the modulation signals are synchronized.

If ringing occurs at the time of rising, the device characteristics may be deteriorated or the device may be destroyed in some cases because an overvoltage of a predetermined voltage or more is applied to the surface conduction electron-emitting device.

Ringing has the following effects on the surface conduction electron-emitting device.

Before that, first, the memory function of the electron emission characteristic of the surface conduction electron-emitting device will be described.

The inventors of the present invention have driven the surface conduction electron-emitting device, which has been subjected to the energization forming treatment and the energization activation treatment in advance, in an environment in which the partial pressure of the organic gas is reduced, and measured the electrical characteristics.

FIG. 26 is a graph showing the voltage waveform of the drive signal applied to the surface conduction electron-emitting device. The horizontal axis represents time, and the vertical axis represents the voltage applied to the surface conduction electron-emitting device (hereinafter referred to as device voltage Vf). Note) is shown.

As the drive signal, continuous rectangular voltage pulses are used as shown in FIG. 7A, the voltage pulse application period is divided into three periods, that is, the first period to the third period, and within each period. The same pulse was applied every 100 pulses. The waveform of the voltage pulse is shown enlarged in FIG.

As a concrete measurement condition, the pulse width of the drive signal is T1 = 66.8 [microse
c] and the pulse cycle is T2 = 16.7 [millisecond]. This is determined with reference to standard driving conditions when the surface conduction electron-emitting device is applied to a general television receiver. However, it is possible to measure the memory function under other conditions. The wiring path from the drive signal source to the surface conduction electron-emitting device is controlled so that the rising time r and the falling time Tf of the voltage pulse effectively applied to the surface conduction electron-emitting device are 100 [ns] or less. The impedance was sufficiently reduced for measurement.

The element voltage Vf is set to Vf = Vf1 in the first period and the third period, and Vf = Vf2 in the second period. Vf
1 and Vf2 are both higher than the electron emission threshold voltage of the surface conduction electron-emitting device, and Vf1 <Vf2.
Was set to satisfy. However, since the electron emission threshold voltage varies depending on the shape and material of the surface conduction electron-emitting device,
The value was appropriately set according to the surface conduction electron-emitting device to be measured.

Regarding the atmosphere around the surface conduction electron-emitting device at the time of measurement, the total pressure is 1 × 10 −6 [t].
orr], and the partial pressure of the organic gas was set to 1 × 10 minus 9th power [torr].

27A and 27B are graphs showing the electrical characteristics of the surface conduction electron-emitting device when the drive signal shown in FIG. 26 is applied. The horizontal axis of FIG. 27A is the device voltage. Vf
The vertical axis represents the current emitted from the surface conduction electron-emitting device (hereinafter, referred to as
The emission current Ie) is measured, the horizontal axis of (b) is the electron voltage Vf, and the vertical axis is the current flowing through the surface conduction electron-emitting device (hereinafter referred to as device current If). .

First, the (device voltage Vf) vs. (emission current Ie) characteristic shown in (a) will be described. First, in the first period, the surface conduction electron-emitting device outputs an emission current in accordance with the characteristic curve Iec (1) in response to the drive pulse. That is, the rising period Tr of the drive pulse
During the period, when the applied voltage Vf exceeds Vth1, the curve Ie
The emission current Ie sharply increases along c (1). Then, during the period of Vf = Vf1, that is, the period of T1, the emission current Ie maintains the magnitude of Ie1. Then, during the falling period Tf of the drive pulse, the emission current Ie sharply decreases along the characteristic curve Iec (1).

Next, when the pulse of Vf = Vf2 starts to be applied in the second period, the characteristic curve changes from Iec (1) to Iec (2). That is, during the rising period Tr of the drive pulse, when the applied voltage Vf exceeds Vth2, the emission current Ie rapidly increases along the characteristic curve Iec (2). Then, during the period of Vf = Vf2, that is, the period of T1, the emission current Ie maintains the magnitude of Ie2. Then, during the falling period Tf of the drive pulse, the emission current Ie sharply decreases along the characteristic curve Iec (2).

Next, in the third period, Vf = Vf again
A pulse of 1 is applied, but at this time, the emission current changes along the characteristic curve Iec (2). That is, the applied voltage Vf is V during the rising period Tr of the drive pulse.
When th2 is exceeded, the emission current Ie rapidly increases along the characteristic curve Iec (2). Then, during the period of Vf = Vf1, that is, the period of T1, the emission current Ie maintains the magnitude of Ie3. Then, the falling period T of the drive pulse
During f, the emission current Ie sharply decreases along the characteristic curve Iec (2).

As described above, since the characteristic curve Iec (2) in the second period is memorized in the third period, the emission current Ie becomes smaller than that in the first period.

Similarly, (element voltage Vf) vs. (element current I
f) Regarding the characteristics, as shown in FIG. 7B, the operation is performed along the characteristic curve Ifc (1) in the first period,
In the second period, it follows the characteristic curve Ifc (2), and in the subsequent third period, it operates along the characteristic curve Ifc (2) recorded in the second period. For convenience of explanation, only three periods, that is, the first to third periods are illustrated, but needless to say, the phenomenon is not limited to these setting conditions. That is, when a pulse voltage is applied to the surface conduction electron-emitting device having a memory function, the characteristic curve shifts when a pulse having a voltage value higher than the voltage value applied before that is applied, and Will be memorized. Since then
The characteristic curve continues to be memorized unless a pulse with a larger voltage value is applied. Such a memory function has not been observed in other electron-emitting devices such as the FE type and can be said to be a function unique to the surface conduction electron-emitting device.

Although the electron emission characteristics of the surface conduction electron-emitting device have been improved and the characteristics thereof have been stabilized as described above, a multi-electron beam source using the surface conduction electron-emitting device will be described below. There was such a problem.

As shown in FIG. 25, the peak value of the voltage applied when driving the multi-electron beam source increases due to the temperature characteristics (temperature drift, etc.) of the drive circuit, or disturbance (noise or static electricity on the circuit, etc.). ) Or the above-mentioned ringing at the rising edge of the waveform may increase instantaneously. Due to this increase, when the peak value of the driving voltage becomes higher than a certain value (the largest voltage among the voltages previously applied to the multi electron source) or more, immediately after the voltage is applied to the multi electron source, Due to the memory characteristics of the surface conduction electron-emitting device, the device characteristics are shifted and the characteristics are newly recorded. Therefore, even if the same voltage as before the characteristic change is applied to the surface conduction electron-emitting device of the multi-electron source, the amount of emitted electrons has decreased.

In particular, when the multi-electron source is driven while scanning in the row direction unit as described above, when the instantaneous drive voltage increases (which is considered to be caused by static electricity), the drive voltage increases. At that moment, an increased drive voltage is applied to the surface conduction electron-emitting device group on the selected row, and the device characteristics are shifted due to the memory characteristics. As a result, the characteristics in the row direction may be uneven in the multi-electron source.

When the multi electron source is applied to an image display device, these phenomena cause problems such as a decrease in the brightness of the display image during driving and an uneven brightness in the row direction of the display image.

The present invention has been made in view of the above-mentioned conventional example, and uses a multi-electron beam source which prevents the occurrence of ringing caused by the rise of a modulation signal and prevents an overvoltage from being applied to the element, and the same. An object is to provide a display device.

[0054]

In order to achieve the above object, the multi-electron beam source of the present invention has the following structure. That is, a multi-electron beam source in which cold cathode elements that emit an amount of electrons according to an applied voltage are arranged in a matrix, and each cold cathode element is provided for one row of the cold cathode element group. A modulation signal of a predetermined width with a wave height corresponding to the value of the image signal for each of the modulation signal generating means for generating the rising and falling timings of the modulation signal, and the modulation signal generated by the modulation signal generating means. On the basis of,
A driving unit that drives the cold cathode device while scanning the cold cathode devices row by row.

Alternatively, it is a multi-electron beam source in which surface conduction electron-emitting devices that emit an amount of electrons according to an applied voltage are arranged in a matrix, and an image signal is a signal with a wave height corresponding to its value. A conversion means for converting into a pulse signal, a means for outputting a signal having the same width as the pulse signal as an output signal shifted by the predetermined time corresponding to each surface conduction electron-emitting device in one row, and a wave height of the output signal. In accordance with the above, the signal converted by the conversion means is turned on / off to generate a modulation pulse signal to be applied to each surface conduction type emission element in each row, and a surface conduction type emission element for each row. Scanning signal applying means for selecting a group and applying a scanning pulse signal of a predetermined crest value and a predetermined width to the surface conduction electron-emitting device group of the selected row, and the above-mentioned variable for each surface conduction electron-emitting device in each row. And a modulation signal applying means for applying a modulated pulse signal generated by the signal generating means.

The display device of the present invention has the following structure. That is, a display device in which cold cathode elements that emit an amount of electrons according to an applied voltage are arranged in a matrix and a light emitting means that emits light according to the amount of electrons emitted from each cold cathode element visualizes an image. With respect to the cold cathode element group for one row, a modulation signal having a wave height corresponding to the value of the image signal for each cold cathode element and having a predetermined width is shifted in the rising and falling timings of the modulation signal. A modulation signal generating unit for generating the modulation signal, and a driving unit for driving the cold cathode device while scanning the cold cathode elements row by row based on the modulation signal generated by the modulation signal generating unit.

Alternatively, surface conduction electron-emitting devices that emit an amount of electrons according to the applied voltage are arranged in a matrix, and the light emitting means emits light according to the amount of electrons emitted from each surface conduction electron-emitting device. A display device for visualizing an image, comprising: a converting means for converting an image signal into a signal having a wave height corresponding to the value; and a signal having the same width as the pulse signal.
Means for outputting as an output signal shifted by the predetermined time corresponding to each surface conduction electron-emitting device in a row, and turning on / off the signal converted by the converting means according to the wave height of the output signal, Modulation signal generating means for generating a modulation pulse signal to be applied to each surface conduction type emission element in each row, and a surface conduction type emission element group is selected for each row, and a predetermined wave is applied to the surface conduction type emission element group of the selected row. Scanning signal applying means for applying a scanning pulse signal having a high value and a predetermined width, and modulation signal applying means for applying the modulation pulse signal generated by the modulation signal generating means to each surface conduction electron-emitting device in each row. .

Further, the control method of the multi-electron beam source of the present invention has the following configuration. That is, a method for controlling a multi-electron beam source, which is configured by arranging cold cathode devices that emit electrons in an amount according to an applied voltage in a matrix,
A modulation signal that generates a modulation signal with a wave height corresponding to the value of an image signal for each cold cathode element group for one row and having a predetermined width for each cold cathode element group by shifting the rising and falling timings of the modulation signal. A generating step and a driving step of driving the cold cathode elements while scanning them row by row based on the modulation signal generated by the modulation signal generating step.

[0059]

BEST MODE FOR CARRYING OUT THE INVENTION An image display device having a display panel using a cold cathode as an embodiment of the present invention will be described in detail below with reference to the drawings.

In the following description, in the present invention, the gradation is expressed by controlling the amplitude of the modulation signal within one horizontal scanning time (1H) as the line-sequential scanning as the scanning method to add gradation to the display image. It is based on.

FIG. 1 is a diagram for explaining a driving device according to the present invention.

The signal flow will be described with reference to FIG. First, the NTSC signal is supplied to the video intermediate frequency circuit 101 and the video detection circuit 102 to extract the video signal S. The video signal S is separated into a horizontal sync signal and a vertical sync signal by the sync separation circuit 103 and input to the timing control circuit 104.

In the timing circuit 104, the timing signal s1 having the same frequency and the timing signal s2 having n times the frequency are generated from the horizontal synchronizing signal.

The video signal is also supplied to the 8-bit A / D conversion circuit 195, sampled at the cycle of the timing signal s2, and modulated into the digital signal s3. The digital signal s3 is stored in the shift register 106 (8 × nbit) as needed in synchronization with the timing signal s2. The shift register 106 is set to 1 in synchronization with the timing signal s2.
Digital data for horizontal pixels is stored,
It is taken into the 1-line memory 107 at timing s1. The data stored in the line memory 107 is supplied to the modulation signal generator 108 at timing s1.

The modulation signal generator 108 includes n D / A conversion circuits DA1 to DAn and n FET Tr1 to Trn, n.
Bit shift register 1083, clock generator 1082, and one-shot multivibrator 1081
Consists of FIG. 2 is a diagram for explaining the modulation signal generator 108.

Next, the operation of the modulation signal generator 108 will be described. The one-shot multivibrator 1081 outputs a signal Sa having the same pulse width as the modulation signal in synchronization with the rising edge of the timing signal s1 (FIGS. 3A and 3C). The clock generator 1082 uses the timing signal Sb used to shift the rising edge of the modulation signal.
Is generated (FIG. 3 (b)). This timing signal Sb
Must be sufficiently shorter than the horizontal synchronization period because the modulation signal shifts by n clocks generated by the generator 1082 at the maximum. nbit shift register 1083
Receives the timing signal Sa as an input, and the timing signal Sb
It operates in synchronization with. Therefore, the outputs Sc1 to Scn of the nbit shift register 1083 have the same pulse width as that of the modulation signal as shown in FIG. 3, and the rising edges thereof are shifted by one cycle of Sb (FIG. 3 (d) to FIG.
(G)).

On the other hand, the 8 × n-bit digital signal s5 supplied from the 1-line memory 107 is input to the 8-bit D / A conversion circuits DA1 to DAn each having n columns, and a voltage having an amplitude corresponding to the image signal. Sd1 to Sdn
Occurs. Sd1 to Sdn are input to the final-stage transistors Tr1 to Trn, respectively, and Tr1 to Trn are o
It is output as the modulation signal s6 during n. The transistors Tr1 to Trn are on while the outputs Sc1 to Scn of the shift register 1083 are high.

Therefore, the modulation signal generator 108 generates the modulation signal s6 whose rising edges are sequentially shifted by one cycle of the timing signal Sb as shown in FIG.

On the other hand, on the scanning signal side, in synchronization with the timing signal s1 supplied from the timing control circuit 104,
There is an mbit ring counter 109 to shift. The output of the ring counter 109 is the m-th row transistor Ts1.
Transistors connected to the gates of Tsm and turned on in synchronization with the timing s1 shift. As a result, as shown in FIG. 24B, the scanning signal s8 shifted by one horizontal scanning period for each row is output to each row wiring.

By driving the display panel 110 as described above, it is possible to shift the rising edge of the pulse signal applied to the cold cathode device which constitutes each pixel for one row. Therefore, it is possible to suppress the occurrence of ringing at the rising edge of the pulse, as described in the section of the prior art and the problem to be solved, such as the destruction of the element,
It is possible to prevent a problem such as a characteristic shift due to an unexpected memory effect.

Although the above description has been made for the case of non-interlace, it is needless to say that the same effect can be obtained also in the case of interlace since the modulated signal can be created by using the same means. Further, the counter circuit may have any configuration as long as the above-described operation is achieved.

When the display panel was actually driven by the configuration of the drive circuit described above, the ringing at the rising edge of the modulation signal, which was seen in the conventional drive system, was hardly seen. [Second Embodiment] The modulation signal generator 108 described in the first embodiment has a configuration in which the rising edges of all the modulation signals are shifted by using the n-bit shift register 1083. However, this method has a drawback in that the circuit becomes complicated and the pulse width of the modulated signal must be reduced in order to secure a width for shifting the rising edge of the signal.

Therefore, the modulation signal generator 10 as shown in FIG.
In the configuration of FIG. 8, a 3-bit shift register 1085 is used instead of the n-bit shift register, and the outputs Sc1, Sc2, Sc3 of the shift register 1085 are connected to the transistors Tr1 to Trn at every third intervals. The modulated signals at this time are Sc1 to Sc3 as shown in FIG.
In synchronism with the above, the rising edge is deviated in the cycle of three elements. With this change, the circuit can be simplified and the pulse width of the modulation signal can be increased.

As described above, as a result of driving the display panel 110 with the circuit in which the configuration of the modulation signal generator 108 is changed, the ringing at the rising edge of the modulation signal is almost suppressed as in the device of the first embodiment. It was being done. Therefore, it was found that even if the structure of the modulation signal generator 108 is simplified as described above and the rising edge of the modulation signal is shifted by three cycles, it is sufficiently effective in reducing ringing. (Structure and Manufacturing Method of Display Panel) Next, the structure and manufacturing method of the display panel 110 of the image display device realized by the driving device in the first and second embodiments will be described with reference to specific examples. To do.

FIG. 7 shows the display panel 1 used in the embodiment.
Figure 10 is a perspective view of 10 of the panel 1 to show the internal structure
The part is cut away.

In the figure, 1005 is a rear plate, and 1006.
Is a side wall, 1007 is a face plate, 1005
˜1007 form an airtight container for maintaining a vacuum inside the display panel. 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.

The rear plate 1005 has a substrate 1001.
Are fixed, but N × M surface conduction electron-emitting devices 1002 are formed on the substrate. (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 = 10
It is desirable to set the number to 00 or more. In this embodiment, N = 3072 and M = 1024. ) The N × M surface conduction electron-emitting devices are M row-direction wirings 1.
003 and N column-direction wirings 1004 form a simple matrix wiring. The portion constituted by 1001 to 1004 is called a multi-electron beam source. The manufacturing method and structure of the multi-electron beam source will be described later in detail.

In this embodiment, the multi-electron beam source substrate 1001 is fixed to the rear plate 1005 of the airtight container, but the multi-electron beam source substrate 10 is fixed.
01 has sufficient strength, the substrate 10 of the multi-electron beam source is used as a rear plate of the hermetic container.
01 itself may be used.

A fluorescent film 1008 is formed on the lower surface of the face plate 1007. Since the present embodiment is a color display device, the fluorescent film 1008 has 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.
As shown in (A) of FIG. 5, the conductors 1010 are painted in stripes, and black conductors 1010 are provided between the stripes of the phosphor. The purpose of providing the black conductor 1010 is to prevent the display color from shifting even if the electron beam irradiation position is slightly shifted, and to prevent the reflection of external light to prevent the display contrast from lowering. And preventing charge-up of the fluorescent film by the electron beam. Although graphite was used as a main component for the black conductor 1010, other materials may be used as long as they are suitable for the above purpose.

Further, the method of separately applying the phosphors of the three primary colors is not limited to the stripe-shaped arrangement shown in FIG. 8A, and for example, the delta arrangement shown in FIG. Other arrangements may be used.

When a monochrome display panel is produced, a monochromatic phosphor material may be used for the phosphor film 1008, and a black conductive material is not necessarily used.

On the rear plate side surface of the fluorescent film 1008, a metal back 1009 known in the field of CRT is used.
Is provided. The purpose of providing the metal back 1009 is
A part of the light emitted from the fluorescent film 1008 is specularly reflected to improve the light utilization rate, or the fluorescent film 1008
8 to protect it, to act as an electrode for applying an electron beam acceleration voltage, and to act as a conductive path for excited electrons of the fluorescent film 1008. The metal back 1009 was formed by forming a fluorescent film 1008 on the face plate substrate 1007, smoothing the surface of the fluorescent film, and vacuum-depositing Al thereon.
The metal back 1009 is not used when a low voltage fluorescent material is used for the fluorescent film 1008.

Although not used in this embodiment, for the purpose of applying an accelerating voltage and improving the conductivity of the fluorescent film, a transparent material such as ITO is formed between the face plate substrate 1007 and the fluorescent film 1008. Electrodes may be provided.

Further, Dx1 to Dxm and Dy1 to Dyn and Hv are electric connection terminals having an airtight structure provided for electrically connecting the display panel and an electric circuit (not shown). Dx1 to Dxm are the row wirings 10 of the multi-electron beam source.
03, Dy1 to Dyn are column direction wirings 1004 of the multi-electron beam source, and Hv is the metal back 1 of the face plate.
009 electrically.

To evacuate the inside of the airtight container to a vacuum, after assembling the airtight container, an exhaust pipe (not shown) and a vacuum pump are connected, and the inside of the airtight container is reduced to the power of 10 −7 [T].
orr]. Then, the exhaust pipe is sealed, but in order to maintain the degree of vacuum in the airtight container, a getter film (not shown) is formed at a predetermined position in the airtight container immediately before or after the sealing. 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 adsorption 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.

The basic structure and manufacturing method of the display panel 110 of this embodiment have been described above.

Next, a method of manufacturing the multi-electron beam source used in the display panel 110 of the above embodiment will be described. The multi-electron beam source used in the image display device is not limited to the material, shape, or manufacturing method of the surface conduction electron-emitting device as long as it is an electron source in which the surface conduction electron-emitting device is wired in a simple matrix. Therefore, for example, a surface conduction electron-emitting device or F
An E type or MIM type cold cathode device can also be used.

However, under the circumstances where a display device having a large display screen and being inexpensive is demanded, the surface conduction electron-emitting device is particularly preferable among these cold cathode devices.
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, but this achieves a large area and a reduction in manufacturing cost. Is a disadvantageous factor.
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. That point,
Since the surface conduction electron-emitting device is relatively simple to manufacture,
It is easy to increase the area and reduce the manufacturing cost.

The inventors have also 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. There is. 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 display device. 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 configuration, 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 many devices are arranged in a simple matrix will be described. (Preferable element structure and manufacturing method of surface conduction electron-emitting device) A typical structure 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 different types. (Plane-type surface conduction electron-emitting device) First, the element structure and manufacturing method of the plane-type surface conduction electron-emitting device will be described. FIG. 9 is a plan view (a) and a cross-sectional view (b) for explaining the configuration of the flat surface conduction electron-emitting device. In the figure, 1101 is a substrate, 1102 and 1103 are element electrodes, 1104 is a conductive thin film, 1105 is an electron emission portion formed by an energization forming process, and 1113 is a thin film formed by an energization activation process.

As the substrate 1101, for example, various glass substrates such as quartz glass and soda lime glass, various ceramic substrates such as alumina, or an insulating layer made of, for example, SiO 2 is laminated on the above various substrates. Substrate, etc. can be used.

Further, the device electrodes 1102 and 1103 provided on the substrate 1101 so as to face each other in parallel to the substrate surface are made of a conductive material. For example, N
i, Cr, Au, Mo, W, Pt, Ti, Cu, Pd,
A material may be appropriately selected from metals such as Ag, alloys of these metals, metal oxides such as In2O3-SnO2, semiconductors such as polysilicon, and the like. To form the electrodes, film-forming techniques such as vacuum deposition and photolithography,
It can be easily formed by using a combination of patterning techniques such as etching, but it may be formed by using other methods (for example, printing techniques).

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 value from the range of several hundreds of angstroms to several hundreds of micrometers. It is in the range of ten micrometers. 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 diameter of the fine particles used for the fine particle film is in the range of several angstroms to several thousand angstroms, but the range of 10 angstroms to 200 angstroms is particularly preferable. 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 satisfactorily performing energization forming described later, conditions necessary for setting the electric resistance of the fine particle film itself to an appropriate value described later. , And so on. In particular,
The setting is made in the range of several Angstroms to several thousand Angstroms, and a preferable value 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, Cr, Fe, Zn, Sn, T
a, W, Pb, and other metals, PdO, S
Oxides such as nO2, In2O3, PbO, Sb2O3, etc .; HfB2, ZrB2, LaB6, CeB6,
Borides such as YB4, GdB4, etc., Ti
Carbides including C, ZrC, HfC, TaC, SiC, WC, etc., nitrides including TiN, ZrN, HfN, etc., semiconductors including Si, Ge, etc., carbon, etc. And these are appropriately selected from these.

As described above, the conductive thin film 1104 is formed of a fine particle film, and its sheet resistance value is
It was set to be included in 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. 9, 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 electrically higher resistance than 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 diameter of several angstroms to several hundred angstroms may be arranged in the cracks. Since it is difficult to accurately and accurately illustrate the actual position and shape of the electron-emitting portion, the electron-emitting portion is schematically shown in FIG.

The thin film 1113 is a thin film made of carbon or a carbon compound, and covers the electron emitting portion 1105 and its vicinity. The thin film 1113 is formed by performing an energization activation process described later after the energization forming process.

The thin film 1113 is any one of single crystal graphite, polycrystalline graphite, amorphous carbon, or a mixture thereof, and the film thickness is 500 [angstrom] or less, but 300 [angstrom] or less. Is more preferable.

Since it is difficult to accurately illustrate the actual position and shape of the thin film 1113, it is schematically shown in FIG. Further, in the plan view (a), the thin film 111 is formed.
The device from which a part of 3 is removed is shown.

Although the basic structure of a preferable element has been described above, the following element is used in the embodiment.

That is, soda lime 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
The thickness of the fine particle film was about 100 [angstrom] and the width W was 100 [micrometer] using dO.

Next, a method for manufacturing a suitable plane type surface conduction electron-emitting device will be described. (A) to (d) of FIG.
9A and 9B are cross-sectional views for explaining the 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. 10A, device electrodes 1102 and 1103 are formed on a substrate 1101.

Before forming, the substrate 1 is formed.
After sufficiently washing 101 with a detergent, pure water and an organic solvent,
The material of the device electrode is deposited. As a method of depositing,
For example, a vacuum film forming technique such as an evaporation method or a sputtering method may be used. After that, the deposited electrode material is patterned using photolithography and etching technology,
A pair of device electrodes (1102 and 1103) shown in (a).
To form

2) Next, a conductive thin film 1104 is formed as shown in FIG.

In forming the film, first, the organometallic solution is applied to the substrate (a), dried, and heated and baked to form a fine particle film, which is then patterned into a predetermined shape by photolithography and etching. . here,
The organic metal solution is a solution of an organic metal compound containing a material of fine particles used for the conductive thin film as a main element. Specifically, Pd is used as the main element in this embodiment. Further, although the dipping method is used as the coating method in the embodiment, other methods such as a spinner method and a spray method may be used.

Further, as a method for forming a conductive thin film formed of a fine particle film, other than the method of applying the organic metal solution used in this embodiment, for example, a vacuum vapor deposition method, a sputtering method, or a chemical vapor deposition method. The law may be used.

3) Next, as shown in FIG. 11C, the forming power supply 1110 to the device electrodes 1102 and 110 are connected.
3, an appropriate voltage is applied, and an energization forming process is performed to form the electron-emitting portion 1105.

The energization forming treatment means that the electroconductive thin film 1104 made of a fine particle film is energized so that a part of the electroconductive thin film 1104 is appropriately destroyed, deformed or altered to change to a structure suitable for electron emission. It is a process that causes it. A portion of the conductive thin film made of a fine particle film that has been changed to a structure suitable for emitting electrons (that is, the electron emitting portion 110
In 5), an appropriate crack is formed in the thin film.
Note that the electric resistance measured between the element electrodes 1102 and 1103 after the formation is significantly increased as compared with before the formation of the electron emission portion 1105.

In order to explain the energizing method in more detail, FIG. 11 shows an example of an appropriate voltage waveform applied from the forming power supply 1110. When forming a conductive thin film made of a fine particle film, a pulsed voltage is preferable, and in the case of the present embodiment, a triangular wave pulse having a pulse width T1 is continuously formed at a pulse interval T2 as shown in FIG. Applied to. At that time, the peak value Vpf of the triangular wave pulse was sequentially increased. In addition, a monitor pulse Pm for monitoring the state of formation of the electron-emitting portion 1105 was inserted between triangular-wave pulses at appropriate intervals, and the current flowing at that time was measured by an ammeter 1111.

In the embodiment of the present invention, for example, 1
In a vacuum atmosphere of 0 to the minus 5th 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 one by one. And the triangular wave is 5
Each time a pulse is applied, the monitor pulse P
m 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 [ohm], 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 preferred method for the surface conduction electron-emitting device of this embodiment, and the design of the surface conduction electron-emitting device such as the material and film thickness of the fine particle film or the device electrode spacing L is changed. In this 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
The electron emission characteristics are improved.

The energization activation process is a process of energizing the electron-emitting portion 1105 formed by the energization forming process under appropriate conditions 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 the member 1113. Note that by performing the energization activation process, the emission current at the same applied voltage can be typically increased by 100 times or more as compared with before the energization activation process.

Specifically, 10 to the fourth power of 4 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 of single crystal graphite, polycrystalline graphite, and amorphous carbon, or a mixture thereof, and has a thickness of 500.
[Angstrom] or less, more preferably 300 [angstrom] or less.

In order to explain the energization method in more detail, FIG. 12A shows an example of an appropriate voltage waveform applied from the activation power supply 1112. In the present embodiment, the energization activation process is performed by periodically applying a rectangular wave of a constant voltage. Specifically, the rectangular wave voltage Vac is 14
[V], pulse width T3 is 1 [millisecond], pulse interval T4
Was set to 10 [milliseconds]. 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 change the conditions accordingly.

Reference numeral 1114 shown in FIG. 9D is an anode electrode for capturing the emission current Ie emitted from the surface conduction electron-emitting device, to which a DC high voltage power supply 1115 and an ammeter 1116 are connected. The substrate 1101 is
When the activation process is performed after being incorporated in the display panel, the phosphor screen of the display panel is used as the anode electrode 1114.

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 1112 is monitored.
Control the operation of. An example of the emission current Ie measured by the ammeter 1116 is shown in FIG.
When the application of the pulse voltage starts from 12, the emission current Ie increases with the passage of time, but eventually saturates and hardly increases. As described above, when the emission current Ie is almost saturated, the voltage application from the activation power supply 1112 is stopped, and the energization activation process is ended.

The above energization conditions are preferable conditions for the surface-conduction type electron-emitting device of this embodiment, and when the design of the surface-conduction type 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. 10E was manufactured. (Vertical type surface conduction electron-emitting device) Next, another typical configuration of the surface conduction type electron emission device in which the electron emission portion or its periphery is formed of a fine particle film, that is, the configuration of the vertical type surface conduction electron emission device. Will be described.

FIG. 13 is a schematic sectional view for explaining the basic structure of the vertical type, in which 1201 is a substrate.
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 vertical type is different from the above-described flat type in that one of the element electrodes (1202) is provided on the step forming member 1206, and the conductive thin film 1204 covers the side surface of the step forming member 1206. The point is that they are covered. Therefore, the element electrode interval L in the planar type shown in FIG.
Is the step height L of the step forming member 1206 in the vertical type.
s. In addition, the substrate 1201, the element electrode 1
202 and 1203, conductive thin film 1 using fine particle film
204, the materials listed in the description of the planar type can be used in the same manner. An electrically insulating material such as SiO2 is used for the step forming member 1206.

Next, a method of manufacturing a vertical surface conduction electron-emitting device will be described. FIGS. 14A to 14F are cross-sectional views for explaining a manufacturing process.
Same as 3.

1) First, as shown in FIG. 14A, a device electrode 1203 is formed on a substrate 1201.

2) Next, as shown in FIG. 11B, an insulating layer for forming the step forming member is laminated. The insulating layer may be formed by laminating SiO2 by sputtering, for example, but other film forming methods such as vacuum deposition or printing may be used.

3) Next, as shown in FIG. 11C, the device electrode 1202 is formed on the insulating layer.

4) Next, as shown in FIG. 10D, a part of the insulating layer is removed by using, for example, an etching method to expose the device electrode 1203.

5) Next, as shown in FIG. 13E, 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 emitting portion. The same process as the planar energization forming process described with reference to FIG. 10C may be performed.

7) Next, as in the case of the planar type, an energization activation process is performed to deposit carbon or a carbon compound in the vicinity of the electron emitting portion. The same process as the planar energization activation process described with reference to FIG. 10D may be performed.

As described above, the vertical type surface conduction electron-emitting device shown in FIG. 14F was manufactured. (Characteristics of surface conduction electron-emitting device used for display device)
The device configuration and manufacturing method of the planar and vertical type surface conduction electron-emitting devices have been described. Next, the characteristics of the device used in the display device will be described.

FIG. 15 shows typical examples of (emission current Ie) vs. (device applied voltage Vf) characteristics and (device current If) vs. (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 in 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
The emission current Ie sharply increases when a voltage of the above magnitude is applied to the element, while the emission current Ie is hardly detected at a voltage lower than the threshold voltage Vth.

That 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 could 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, by using the second characteristic or the third characteristic, the light emission luminance can be controlled, so that a gradation display can be performed. (Structure of multi-electron beam source in which a large number of elements are wired in a simple matrix) Next, the structure of a multi-electron beam source in which the above surface conduction electron-emitting devices are arranged on a substrate and wired in a simple matrix will be described.

FIG. 16 is a plan view of the multi-electron beam source used in the display panel of FIG. On the board,
Surface conduction type emission elements similar to those shown in FIG. 9 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.

A cross section taken along the line AA 'in FIG. 16 is shown in FIG.
Shown in

The multi-electron source having such a structure is
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.

FIG. 18 shows a display panel using the cold cathode device manufactured by the above-described manufacturing method as an electron beam source so that image information provided by various image information sources such as television broadcasting can be displayed. FIG. 3 is a diagram showing an example of a multi-function display device configured in FIG.

In the drawing, 110 is a display panel and 21
Reference numeral 01 denotes a display panel drive circuit, which corresponds to blocks 101 to 109 in FIG. 2102 is a display controller, 2103 is a multiplexer, 2104 is a decoder, 2105 is an input / output interface circuit, 2
106 is a CPU, 2107 is an image generation circuit, 2108 and 2109 and 2110 are image memory interface circuits, 2111 is an image input interface circuit,
2112 and 2113 are TV signal receiving circuits, 2114
Is an input unit.

When the display device receives a signal including both video information and audio information, such as a television signal, it naturally reproduces audio at the same time as displaying video. Descriptions of circuits, speakers, etc. relating to reception, separation, reproduction, processing, and storage of audio information not directly related to the features of the invention will be omitted.

The functions of the respective parts will be described below along the flow of the image signal.

First, the TV signal receiving circuit 2113 is a circuit for receiving a TV image signal transmitted using a wireless transmission system such as radio waves or spatial optical communication. The TV signal system to be received is not particularly limited, and may be a prescription system such as an NTSC system, a PAL system, or a SECAM system. Further, a TV signal (for example, a so-called high-definition TV such as the MUSE method) including a larger number of scanning lines than these is suitable for taking advantage of the display panel suitable for a large area and a large number of pixels. It is a signal source. The TV signal received by the TV signal receiving circuit 2113 is output to the decoder 2104.

The TV signal receiving circuit 2112 is a circuit for receiving a TV image signal transmitted using a wire transmission system such as a coaxial cable or an optical fiber. As with the TV signal receiving circuit 2113, the type of the TV signal to be received is not particularly limited, and the TV signal received by this circuit is also output to the decoder 2104.

Further, the image input interface circuit 21
Reference numeral 11 denotes a circuit for capturing an image signal supplied from an image input device such as a TV camera or an image reading scanner. The captured image signal is output to a decoder 2104.

The image memory interface circuit 2
110 is a video tape recorder (hereinafter abbreviated as VTR)
Is a circuit for capturing the image signal stored in the decoder 2104. The captured image signal is output to the decoder 2104.

The image memory interface circuit 2
Reference numeral 109 denotes a circuit for capturing an image signal stored in the video disk, and the captured image signal is output to the decoder 2104.

The image memory interface circuit 2
Reference numeral 108 denotes a circuit for taking in an image signal from a device that stores still image data, such as a so-called still image disk.
It is output to 04.

Further, the input / output interface circuit 210
Reference numeral 5 denotes a circuit for connecting the present display device to an external computer, a computer network, or an output device such as a printer. In addition to inputting and outputting image data, character data, and graphic information, control signals and numerical data can be input and output between the CPU 2106 included in the display device and the outside in some cases. .

Further, the image generation circuit 2107 is provided with image data, character / graphic information, or CPU which is externally input via the input / output interface circuit 2105.
A circuit for generating display image data based on the image data and character / graphic information output from 2106.
Within this circuit, for example, a rewritable memory for storing image data and character / graphic information, a read-only memory for storing image patterns corresponding to character codes, and a processor for performing image processing Circuits necessary for generating an image, such as those described above, are incorporated.

The display image data generated by this circuit is output to the decoder 2104, but in some cases, it is also possible to input / output to / from an external computer network or printer via the input / output interface circuit 2105.

Further, the CPU 2106 mainly performs operations related to operation control of the display device and generation, selection and editing of a display image.

For example, a control signal is output to the multiplexer 2103 to appropriately select or combine image signals to be displayed on the display panel. At that time, a control signal is generated for the display panel controller 2102 according to the image signal to be displayed, and the screen display frequency, the scanning method (for example, interlaced or non-interlaced), the number of scanning lines in one screen, etc. are displayed. The operation of the device is controlled appropriately.

Image data or character / graphic information is directly output to the image generation circuit 2107, or an external computer or memory is accessed via the input / output interface circuit 2105 to generate image data or character / figure information. Enter graphic information.

It should be noted that the CPU 2106 may of course be involved in work for purposes other than this. For example,
It may be directly related to a function of generating and processing information, such as a personal computer or a word processor.

Alternatively, as described above, the computer may be connected to an external computer network via the input / output interface circuit 2105, and work such as numerical calculation may be performed in cooperation with an external device.

The input unit 2114 is the CPU 21
06 is for the user to input commands, programs, data, and the like. For example, in addition to a keyboard and a mouse, various input devices such as a joystick, a barcode reader, and a voice recognition device can be used.

Further, the decoder 2104 has the above-mentioned 2107.
And 2113 are circuits for inversely converting various image signals inputted from 2113 into three primary color signals or luminance signals and I and Q signals. It is to be noted that the decoder 2104 desirably includes an image memory therein, as indicated by a dotted line in FIG. This is to handle a television signal that requires an image memory for reverse conversion, such as the MUSE method. Further, the provision of the image memory makes it easy to display a still image, or cooperates with the image generation circuit 2107 and the CPU 2106 to perform image processing and editing such as thinning, interpolation, enlargement, reduction, and composition. This is because there is an advantage that it can be easily performed.

Further, the multiplexer 2103 has the C
A display image is appropriately selected based on a control signal input from the PU 2106. That is, the multiplexer 2103 selects a desired image signal from the inversely converted image signals input from the decoder 2104 and outputs the selected image signal to the drive circuit 2101. In that case, by switching and selecting an image signal within one screen display time, it is possible to divide one screen into a plurality of areas and display different images depending on the areas, as in a so-called multi-screen TV. .

Also, the display panel controller 2
Reference numeral 102 denotes a circuit for controlling the operation of the drive circuit 2101 based on a control signal input from the CPU 2106.

First, as a component related to the basic operation of the display panel, for example, a signal for controlling the operation sequence of a drive power source (not shown) for the display panel is output to the drive circuit 2101.

Further, regarding the driving method of the display panel, for example, a signal for controlling the screen display frequency and the scanning method (for example, interlace or non-interlace) is output to the drive circuit 2101.

In some cases, control signals relating to image quality adjustment such as brightness, contrast, color tone and sharpness of a display image may be output to the drive circuit 2101.

The drive circuit 2101 is a circuit for generating a drive signal to be applied to the display panel 110, and the image signal input from the multiplexer 2103 and the display panel controller 210.
It operates on the basis of a control signal inputted from 2.

The functions of the respective parts have been described above. With the configuration illustrated in FIG. 18, the display panel 1 displays image information input from various image information sources in this display device.
It is possible to display in 10.

That is, various image signals such as television broadcasts are inversely converted by the decoder 2104, appropriately selected by the multiplexer 2103, and input to the drive circuit 2101. On the other hand, the display controller 2102 generates a control signal for controlling the operation of the drive circuit 2101 according to the image signal to be displayed. The drive circuit 2101 applies a drive signal to the display panel 110 based on the image signal and the control signal.

As a result, the image is displayed on the display panel 110. These series of operations are CP
Controlled by U2106.

Further, in this display device, the image memory built in the decoder 2104 and the image generation circuit 21.
Due to the involvement of 07 and the CPU 2106, not only the one selected from a plurality of image information is displayed, but also the image information to be displayed is enlarged or reduced, for example.
It is also possible to perform image processing such as rotation, movement, edge enhancement, thinning, interpolation, color conversion, image aspect ratio conversion, and image editing such as synthesis, erasure, connection, replacement, and fitting. is there. Although not particularly described in the description of the present embodiment, a dedicated circuit for processing and editing audio information may be provided similarly to the image processing and image editing.

Therefore, the display device is a display device for television broadcasting, a terminal device for a video conference, an image editing device for handling still images and moving images, a computer terminal device, an office terminal device such as a word processor,
It is possible to combine the functions of a game console, etc., with a very wide range of applications for industrial or consumer use.

Note that FIG. 18 merely shows an example of the configuration of a display device using a display panel having a cold cathode element as an electron beam source, and it goes without saying that the present invention is not limited to this. For example, of the constituent elements in FIG. 18, circuits relating to functions that are unnecessary for the purpose of use may be omitted. Conversely, additional components may be added depending on the purpose of use. For example, when the present display device is applied as a video phone, it is preferable to add a transmission / reception circuit including a television camera, an audio microphone, an illuminator, and a modem to the components.

In the present display device, in particular, since the display panel using the surface conduction electron-emitting device as the electron beam source can be easily thinned, the depth of the entire display device can be reduced. In addition, a display panel that uses a cold cathode element as an electron beam source can easily enlarge the screen, has high brightness, and has excellent viewing angle characteristics, so this display device displays a realistic image with rich power and good visibility. It is possible to do

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus.

[0180]

As described above, according to the present invention, when a display panel to which a cold cathode element is applied is driven, it is possible to prevent an overvoltage due to ringing appearing in a driving waveform from being applied, thereby improving the characteristics of the element. It can be prevented from being deteriorated or destroyed.

[0181]

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an image display circuit driving device according to an embodiment.

FIG. 2 is a block diagram of a modulation signal generator in a drive circuit of an image display device.

FIG. 3 is a timing chart in the modulation signal generator.

FIG. 4 is a timing chart of a modulation signal in the modulation signal generator.

FIG. 5 is a block diagram of a modulation signal generator according to a second embodiment.

FIG. 6 is a timing chart of a modulation signal in the modulation signal generator of the second embodiment.

FIG. 7 is a perspective view in which a part of the display panel of the image display device described in the embodiment of the invention is cut away.

FIG. 8 is a plan view illustrating a phosphor array of a face plate of a display panel.

FIG. 9 is a plan view (a) and a sectional view (b) of a planar surface conduction electron-emitting device used in the embodiment.

FIG. 10 is a cross-sectional view showing a manufacturing process of the planar surface conduction electron-emitting device.

FIG. 11 is a diagram showing an applied voltage waveform during energization forming processing.

FIG. 12 shows an applied voltage waveform (a) during energization activation processing;
This is a change (b) in the emission current Ie.

FIG. 13 is a sectional view of a vertical surface conduction electron-emitting device used in the embodiment.

FIG. 14 is a cross-sectional view illustrating a manufacturing process of a vertical surface conduction electron-emitting device.

FIG. 15 is a graph showing typical characteristics of the surface conduction electron-emitting device used in the embodiment.

FIG. 16 is a plan view of a substrate of a multi-electron beam source used in the display device of the embodiment.

FIG. 17 is a partial cross-sectional view of a multi-electron beam source substrate used in the display device of the embodiment.

FIG. 18 is a block diagram of a multifunctional image display device using the image display device according to the embodiment of the present invention.

FIG. 19 is a diagram showing an example of a conventionally known surface conduction electron-emitting device.

FIG. 20 is a diagram showing an example of a conventionally known FE type emission device.

FIG. 21 is a diagram showing an example of a conventionally known MIM type emission device.

FIG. 22 is a diagram illustrating a wiring method of an electron-emitting device in which a problem occurs.

FIG. 23 is a diagram illustrating a wiring method of an electron-emitting device in which a problem has occurred.

FIG. 24 is a diagram for explaining a conventional amplitude modulation driving method.

FIG. 25 is a diagram for explaining a problem.

FIG. 26 is a diagram for explaining a problem.

FIG. 27 is a diagram for explaining a problem.

Claims (21)

[Claims] 1. A multi-electron beam source in which cold cathode elements that emit an amount of electrons according to an applied voltage are arranged in a matrix, and each cold cathode element group for one row is Modulation signal generation means for generating a modulation signal of a predetermined width with a wave height corresponding to the value of the image signal for each cold cathode element by shifting the rising and falling timings of the modulation signal, and the modulation signal generation means. A multi-electron beam source, comprising: a driving unit that drives the cold cathode elements while scanning them row by row based on a modulation signal. 2. The modulation signal generating means outputs an image signal,
2. A conversion means for converting into a modulation signal applied to each cold cathode device in each row having a wave height corresponding to the value, and a shift means for shifting a rising timing of the modulation signal by a predetermined time. The multi-electron beam source described in. 3. The shift means outputs a signal having the same width as the modulation signal as an output signal which is shifted by the predetermined time corresponding to each cold cathode element in one row, and the output signal of the output signal. The multi-electron beam source according to claim 2, further comprising switching means for turning on / off the modulation signal by the converting means according to a wave height. 4. The scanning signal applying means, wherein the driving means selects a cold cathode element group for each row and applies a pulse signal of a predetermined peak value and a predetermined width to the cold cathode element group of the selected row,
4. The multi-electron beam source according to claim 1, further comprising a modulation signal applying unit that applies the signal generated by the modulation signal generating unit to each cold cathode element in the selected row. 5. The multi-electron device according to claim 1, wherein the shift means shifts the rising timings of the modulation signals from each other for three consecutive cold cathode elements by the predetermined time. Beam source. 6. The multi-electron beam source according to claim 1, wherein the cold cathode device is a surface conduction electron-emitting device. 7. A multi-electron beam source comprising surface conduction electron-emitting devices, which emit electrons in an amount corresponding to an applied voltage, arranged in a matrix, wherein an image signal is a signal having a wave height corresponding to its value. Converting means for converting the pulse signal to a signal having the same width as the pulse signal as an output signal shifted by the predetermined time corresponding to each surface conduction electron-emitting device in one row; In accordance with the above, the signal converted by the conversion means is turned on / off to generate a modulation pulse signal to be applied to each surface conduction type emission element in each row, and a surface conduction type emission element for each row. Scanning signal applying means for selecting a group and applying a scanning pulse signal of a predetermined crest value and a predetermined width to the surface conduction electron-emitting device group of the selected row; and the modulation signal for each surface conduction electron-emitting device in each row. Multi-electron beam source, characterized in that it comprises a modulation signal applying means for applying a modulated pulse signal generated by the formation means. 8. A cold cathode device that emits an amount of electrons according to an applied voltage is arranged in a matrix, and an image is visualized by a light emitting unit that emits light according to the amount of electrons emitted from each cold cathode device. In the display device, a cold cathode element group for one row is provided with a modulation signal having a wave height corresponding to an image signal value for each cold cathode element and a rising and falling timing of the modulation signal. And a drive means for driving the cold cathode devices while scanning the cold cathode elements row by row based on the modulation signal generated by the modulation signal generation means. apparatus. 9. The modulation signal generating means outputs an image signal,
9. A conversion means for converting into a modulation signal to be applied to each cold cathode device in each row having a wave height corresponding to the value, and a shift means for shifting a rising timing of the modulation signal by a predetermined time. Display device according to. 10. The shift means outputs a signal having the same width as that of the modulation signal as an output signal shifted by the predetermined time in correspondence with each cold cathode element in one row, and the output signal of the output signal. 10. The display device according to claim 9, further comprising switching means for turning on / off the modulation signal by the converting means according to the wave height. 11. The drive means selects a cold cathode element group for each row, and applies a scanning signal applying means for applying a pulse signal of a predetermined peak value and a predetermined width to the cold cathode element group of the selected row, and 11. The display device according to claim 7, further comprising a modulation signal applying unit that applies the signal generated by the modulation signal generating unit to each cold cathode element in the selected row. 12. The display device according to claim 7, wherein the shift means shifts the rising timings of the modulation signals from each other for three consecutive cold cathode elements by the predetermined time. . 13. The display device according to claim 7, wherein the cold cathode device is a surface conduction electron-emitting device. 14. The image signal is a color image signal,
14. The modulation signal generating means generates a modulation signal for each color signal, and the light emitting means includes a fluorescent material in which fluorescent materials of three primary colors of red, green and blue are arranged in a predetermined format. The display device according to claim 1. 15. Surface emitting electron-emitting devices that emit a quantity of electrons according to an applied voltage are arranged in a matrix, and the light-emitting means emits light according to the amount of electrons emitted from each surface-conductive electron emitter. A display device for visualizing an image, comprising: a conversion means for converting an image signal into a signal having a wave height corresponding to the value; and a signal having the same width as the pulse signal to each surface conduction electron-emitting device in one row. Correspondingly, a means for outputting as the output signal shifted by the predetermined time, and turning on / off the signal converted by the converting means in accordance with the wave height of the output signal, for each surface conduction type emission element in each row. A modulation signal generating means for generating a modulation pulse signal to be applied and a surface conduction electron-emitting device group for each row are selected, and a scanning pulse signal having a predetermined peak value and a predetermined width is applied to the surface conduction electron-emitting device group of the selected row. Application That a scanning signal applying means, a display device characterized in that it comprises a modulation signal applying means for applying a modulated pulse signal generated by said modulating signal generating means to each surface conduction electron-emitting devices in each row. 16. A method for controlling a multi-electron beam source, which comprises arranging cold cathode devices emitting a quantity of electrons according to an applied voltage in a matrix, wherein one group of cold cathode device groups is provided. A modulation signal generation step of generating a modulation signal of a predetermined width with a wave height corresponding to the value of the image signal for each cold cathode element by shifting the rising and falling timings of the modulation signal, and the modulation signal generation step. And a driving step of driving the cold cathode elements while scanning the cold cathode elements row by row based on the generated modulation signal. 17. The conversion signal generating step includes a conversion step of converting an image signal into a modulation signal having a wave height corresponding to the value and applied to each cold cathode device in each row, and a rising timing of the modulation signal is predetermined. The method for controlling a multi-electron beam source according to claim 16, further comprising a shift step of shifting the time. 18. The shift step includes the step of outputting a signal having the same width as the modulation signal as an output signal shifted by the predetermined time corresponding to each cold cathode element in one row; 18. The method of controlling a multi-electron beam source according to claim 17, further comprising a switching step of turning on / off the modulation signal by the converting step according to a wave height. 19. The scanning signal applying step of selecting a cold cathode element group for each row and applying a pulse signal of a predetermined peak value and a predetermined width to the cold cathode element group of the selected row in the driving step, and a selecting step. 19. The multi-electron beam source control according to claim 16, further comprising a modulation signal applying step of applying the signal generated by the modulation signal generating step to each cold cathode element in the selected row. Method. 20. The multi-electron device according to claim 16, wherein in the shift step, rising timings of the modulation signals are shifted from each other by the predetermined time for three consecutive cold cathode elements. Beam source control method. 21. The method of controlling a multi-electron beam source according to claim 16, wherein the cold cathode device is a surface conduction electron-emitting device.