JP3226772B2 - Multi-electron beam source and display device using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, two types of electron emitting devices, a hot cathode device and a cold cathode device, are known. Among 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)].

[0005] As a typical example of the device configuration of these surface conduction electron-emitting devices, FIG. Hartw
1 shows a plan view of an element by ell et al. In FIG.
001 is a substrate, and 3004 is a conductive thin film made of a metal oxide formed by sputtering. 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], W
Is set to 0.1 [mm]. For convenience of illustration, the electron emitting portion 3005 is shown in a rectangular shape at the center of the conductive thin film 3004, but this is a schematic one.
It does not faithfully represent the actual position and shape of the electron-emitting portion.

[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 means energizing by applying a constant DC voltage to both ends of the conductive thin film 3004, or a DC voltage which is boosted at a very slow rate of, for example, about 1 V / min.
The electron emitting portion 30 in a state where the conductive thin film 3004 is locally 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 device configuration, FIG. A. 1 shows a cross-sectional view of a device by Spindt et al. In the figure, reference numeral 3010 denotes a substrate;
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 configuration of the FE type, FIG.
There is also an example in which an emitter and a gate electrode are arranged on a substrate almost in parallel with the plane of the substrate, instead of the laminated structure shown in FIG.

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
A typical example of the element configuration of the mold is shown in FIG. The figure is a sectional view, in which 3020 is a substrate, 302
1 is a lower electrode made of a metal, 3022 is a thin insulating layer having a thickness of about 100 Å, and 3023 is a thickness of 80 to 3
The upper electrode is made of a metal of about 00 Å. In the MIM type, the upper electrode 3023 and the lower electrode 30
21 by applying an appropriate voltage to the upper electrode 3.
The electron emission is caused from the surface of H.023.

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, unlike the hot cathode device, which operates by heating the heater, the response speed is slow, and the cold cathode device also has the 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.
As disclosed in 332, methods for arranging and driving a large number of elements are being studied.

As for the application of the surface conduction electron-emitting device, for example, an image forming apparatus such as an image display device and an image recording device, a charged beam source, and the like have been studied.

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. The flat panel display 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 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 electric wiring method shown in FIG. 20, for example. That is, a large number of cold cathode devices are two-dimensionally arranged,
A multi-electron beam source in which these elements 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 electrical 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 size 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. Elements that are sufficient to perform are arranged and wired.

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, the column direction wiring 4003
Is applied with a drive voltage Ve for outputting an electron beam. 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, a multi-electron beam source in which cold cathode devices are arranged in a simple matrix has various applications. For example, if an electric signal corresponding to image information is appropriately applied, it is suitable as an electron source for an image display device. Can be used.

When a surface conduction type electron beam source is manufactured, a process called 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 the forming.

After the energization is completed, carbon or a carbon compound is newly deposited on the electron emission portion or in the vicinity thereof even when the surface conduction type emission device is energized in order to stabilize the electron emission characteristics of the surface conduction type emission device. In order 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 that the partial pressure of the organic gas in the atmosphere is reduced and maintained at 10 −8 [torr] or less, and more preferably 10 −10 if possible.
It is desirable to keep it to the power [torr] or less. Note that the partial pressure of an organic gas means that carbon and hydrogen are the main components and the mass number is 1
It is a value obtained by integrating the 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 organic gas in the surrounding environment of the surface conduction electron-emitting device, a vacuum vessel containing a substrate on which the surface conduction electron-emitting device is formed is heated so that the surface of each member in the container is heated. While desorbing the adsorbed organic gas molecules, a method of evacuating using a vacuum pump that does not use oil, such as a solution pump or an ion pump, may be used.

After the partial pressure of the organic gas is reduced in this way, it is possible to maintain the state by using a vacuum pump that does not use oil and continuing exhaustion thereafter. However, the method of always evacuating with a vacuum pump may be disadvantageous in terms of capacity, power consumption, weight, price, etc., depending on the application purpose. Therefore, for example, when applying a surface conduction electron-emitting device to an image display device, after sufficiently desorbing the organic gas molecules and reducing the partial pressure of the organic gas, a getter film is formed in a vacuum vessel. The state is maintained by sealing the exhaust pipe.

By performing such a treatment, it is possible to prevent the surface conduction type element after the energization activation treatment from changing over time or depositing new carbon or a carbon compound due to the energization, thereby stabilizing the electron emission characteristics. Can be.

[0030]

However, the following problems have actually occurred in the multi-electron beam source in which the cold cathode devices as described above are arranged in a simple matrix wiring. Note that a signal applied to the row direction wiring is referred to as a scanning signal, and a signal applied to the column direction wiring is referred to as a modulation signal.

FIG. 21 is a time chart for explaining a scanning signal and a modulation signal in the conventional pulse width modulation driving method.

As shown in FIG. 21, in period K, the cold cathode element in row i of FIG. 22 is driven, in period K + 1, the cold cathode element in row i + 1 is driven, and in period K + 2, the cold cathode element in row i + 2 is driven. During the driving, a scanning signal is applied to the row direction wiring and a modulation signal is applied to the column direction wiring. As the modulation signal,
As shown in FIG. 21, an image is displayed by applying pulses having different time widths with the same rising edge and operating the pulse width in accordance with the image signal.

However, a conventional driving device can output a rectangular wave without ringing as shown in FIG. 21 in a no-load state. However, when a multi-electron source is actually driven as a load, the waveform of the waveform is reduced. Large ringing occurred at the rising portion (FIG. 23). The inventors believe that the cause may be not the multi-electron source itself but the inductive components of a very large number of cables connecting between the driving device and the multi-electron source, and the effects of the capacitive components between them. Is thinking. Especially this ringing
The rising time of the pulse is large, and the falling time is almost inconspicuous as compared with the rising time. The inventors have confirmed that this is because the rising of the modulation signal is synchronized.

If ringing occurs at the time of rising, the ringing acts in a direction in which an overvoltage of a predetermined voltage or more is applied to the cold cathode device, which may cause deterioration of the device or, in some cases, breakage of the device.

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

First, the memory function of the electron emission characteristics of the surface conduction electron-emitting device will be described.

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

FIG. 24 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 the element voltage Vf). ) Is shown.

As the drive signal, a continuous rectangular voltage pulse is used as shown in FIG. 3A, and the application period of the voltage pulse is divided into three periods of a first period to a third period. The same pulse was applied every 100 pulses. The waveform of the voltage pulse is shown enlarged in FIG.

As a specific measurement condition, the pulse width of the drive signal is set to T 2 = 66.8 [microsec.
c], and the pulse period was set to T 1 = 16.7 [millisec]. 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. Note that the wiring path from the drive signal source to the surface conduction electron-emitting device is set so that the rise time Tr and the fall time Tf of the voltage pulse effectively applied to the surface conduction electron-emitting device become 100 [ns] or less. The measurement was performed with the impedance sufficiently reduced.

The element voltage Vf was Vf = Vf1 in the first and third periods, 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,
It was set appropriately according to the surface conduction electron-emitting device to be measured.

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

FIGS. 25A and 25B are graphs showing the electrical characteristics of the surface conduction electron-emitting device when the drive signal shown in FIG. 24 is applied. The horizontal axis of FIG. Vf,
The vertical axis represents the current emitted from the surface conduction electron-emitting device (hereinafter, referred to as
The horizontal axis of (b) represents the electron voltage Vf, and the vertical axis represents the measured value of 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 FIG. First, in the first period, an emission current is output from the surface conduction electron-emitting device according to the characteristic curve Iec (1) in response to the driving 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 increases rapidly 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 sharply 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
One pulse is applied, and at this time, the emission current changes along the characteristic curve Iec (2). That is, during the rising period Tr of the drive pulse, the applied voltage Vf is V
When it exceeds th2, the emission current Ie sharply increases along the characteristic curve Iec (2). Then, during the period of Vf = Vf1, that is, during 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 is smaller than that in the first period.

Similarly, (element voltage Vf) vs. (element current I
f) Regarding the characteristics, the operation is performed along the characteristic curve Ifc (1) in the first period as shown in FIG.
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) written in the second period. For convenience of explanation, only three periods of the first to third periods have been illustrated, but it is a matter of course that the present invention is not limited to this set condition. That is, when a pulse voltage is applied to the surface conduction electron-emitting device provided with the memory function, the characteristic curve shifts when a pulse having a voltage value larger than the voltage value applied before that is applied, and It is memorized. Since then
Unless a pulse having a larger voltage value is applied, the characteristic curve continues to be memorized. 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.

As described above, the electron emission characteristics of the surface conduction electron-emitting device have been improved and the device has been devised to stabilize the characteristics. However, a multi-electron beam source using the surface conduction electron-emitting device will be described below. Such a problem had occurred.

As shown in FIG. 23, the peak value of the voltage applied when driving the multi-electron beam source increases due to the temperature characteristics (temperature drift or the like) of the driving circuit, or the disturbance (such as noise or static electricity on the circuit). ) Or may increase instantaneously due to ringing at the rising edge of the waveform described above. Due to this increase, when the peak value of the driving voltage becomes larger than a certain value (the largest voltage previously applied to the multi-electron source), 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. For this reason, even when the same voltage as before the characteristic change is applied to the surface conduction electron-emitting device of the multi-electron source, a phenomenon in which the amount of emitted electrons is reduced has occurred.

In particular, when the multi-electron source is driven while scanning in the unit of the row direction as described above, if an instantaneous increase in drive voltage (due to noise, static electricity, waveform deformation due to distributed capacitance, etc.) occurs, The increased driving voltage is applied to the surface conduction electron-emitting device group on the selected row at the moment when the driving voltage increases, and the device characteristics are shifted by the memory characteristics. As a result, the characteristics in the row direction may be uneven in the multi-electron source.

When these phenomena are applied to an image display apparatus, these phenomena have caused problems such as a decrease in luminance of a display image during driving, and luminance unevenness in a 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 for preventing the occurrence of ringing caused by the rise of a modulation signal and for preventing an overvoltage from being applied to an element. It is an object 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 configuration. That is, a multi-electron beam source in which surface conduction electron-emitting devices that emit electrons in an amount corresponding to the voltage application time are arranged in a matrix, and for a row of surface conduction electron-emitting devices, A modulation signal generation unit that generates a modulation signal having a predetermined wave height of a time width corresponding to a value of an image signal for each surface conduction type emission element by synchronizing a rear end of the modulation signal, and a modulation signal generation unit. based on the modulated signals, the includes a drive means for each surface conduction electron-emitting devices to drive while scanning each row, the surface conduction electron-emitting device, if a pulse voltage is applied, earlier Applied to
Pulse voltage with a voltage value greater than the
Then, the characteristic curve of applied voltage and emission current shifts,
Has a memory characteristic in which the characteristic curve is stored .

Alternatively, there is provided a multi-electron beam source in which surface conduction electron-emitting devices for emitting an amount of electrons corresponding to a voltage application time are arranged in a matrix, wherein a sampling means for sampling an image signal; A counter for setting the maximum value that can be sampled by the means to the maximum value, starting counting by the counter means with the value of the image signal sampled by the sampling means as an initial value, and determining the timing when the maximum value is reached by a pulse signal. Determining means for determining the rising timing, rising at the timing determined by the determining means,
A modulation signal generating means for generating a modulation pulse signal that falls at a predetermined timing; and a surface conduction type emission element group selected for each row, and a predetermined peak value and a predetermined width are assigned to the surface conduction type emission element group of the selected row. Scanning signal applying means for applying a scanning pulse signal; and modulation signal applying means for applying a modulation pulse signal generated by the modulation signal generating means to each surface conduction electron-emitting device in each row. When a pulse voltage is applied, the conduction type emission element
Pulse with a voltage value greater than the previously applied voltage value
When voltage is applied, the characteristic curve of applied voltage and emission current
Has a memory characteristic whose characteristic curve is stored .

The display device of the present invention has the following configuration. That is, surface conduction type emission devices that emit an amount of electrons according to the voltage application time are arranged in a matrix, and an image is emitted by a light emitting unit that emits light according to the amount of electrons emitted from each surface conduction type emission device. A display device for visualizing, wherein a modulation signal having a predetermined wave height of a time width according to a value of an image signal is provided for each surface conduction type emission element group for one row, for the surface conduction type emission element group. A modulation signal generating means for generating a signal by synchronizing a rear end of the light emitting element; and a driving means for driving the surface conduction electron-emitting device while scanning the row by row based on the modulation signal generated by the modulation signal generating means. And a pulse voltage is applied to the surface conduction electron-emitting device.
Is greater than the previously applied voltage
When a pulse voltage of the pressure value is applied, the applied voltage and the emission current
Characteristic curve shifts and that characteristic curve is stored in memory.
That has a memory characteristic.

Alternatively, a surface conduction electron-emitting device that emits an amount of electrons according to a voltage application time is arranged in a matrix, and light-emitting means that emits light according to the amount of electrons emitted from each surface conduction electron-emitting device. A display device for visualizing an image by: sampling means for sampling an image signal;
A counter that sets the maximum value that can be sampled by the sampling unit to the maximum value, starts counting by the counter unit with the value of the image signal sampled by the sampling unit as an initial value, and outputs a pulse when the maximum value is reached. Determining means for determining as the rising timing of the signal, modulation signal generating means for generating a modulated pulse signal that rises at the timing determined by the determining means and falls at a predetermined timing, and a surface conduction type emission element group for each row. Scanning signal applying means for selecting and applying a scanning pulse signal having a predetermined peak value and a predetermined width to the surface conduction electron-emitting elements in the selected row; and the modulation signal generating means for each surface conduction electron-emitting element in each row. Modulation signal applying means for applying a modulation pulse signal generated by The surface conduction electron-emitting device, the pulse
When a voltage is applied, the voltage value applied before
When a pulse voltage with a voltage value larger than
The characteristic curves of pressure and emission current shift, and the characteristic curves
Has a memory characteristic to be stored.

The control method of the multi-electron beam source according to the present invention has the following configuration. That is, a method of controlling a multi-electron beam source in which surface conduction electron-emitting devices that emit electrons in an amount corresponding to a voltage application time are arranged in a matrix, wherein the surface conduction electron -emitting device has a pulse voltage of Application
Is greater than the previously applied voltage value
When a pulse voltage of a voltage value is applied, the applied voltage and the
The flow characteristic curve shifts and the characteristic curve is stored in memory.
Has a memory characteristic, relative to the surface conduction electron-emitting device group for one line, a modulation signal of a predetermined pulse height of time width corresponding to the value of the image signal for each surface conduction electron-emitting device, the modulation A modulation signal generation step of synchronizing and generating the rear end of the signal,
And a driving step of driving the surface conduction electron-emitting element while scanning the row by row based on the modulation signal generated by the modulation signal generation means.

[0059]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image display apparatus using a multi-electron beam source will be described in detail as an embodiment of the present invention with reference to the drawings.

Hereinafter, in order to give a gradation to a display image, the scanning method is line-sequential scanning, and the ratio of the display period within one horizontal scanning time (1H) is controlled by the time width of the modulation signal, thereby expressing the gradation. It is basically to do. <Configuration of Multi-Electron Beam Source> FIG. 1 is a diagram for explaining a driving device according to the present embodiment.

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, and the video signal S is extracted. The video signal S is separated into a horizontal synchronizing signal and a vertical synchronizing signal by a sync separation circuit 103 and is input to a timing control circuit 104.

In the timing control circuit 104, a timing signal s1 having the same frequency, a timing signal s2 having n times the frequency and a timing signal s3 having a 255 times frequency of s1 are generated from the horizontal synchronizing signal. Here, n is the number of elements in the row direction of the image display panel 110.

The video signal is also supplied to an 8-bit A / D conversion circuit 105, sampled at the cycle of the timing signal s2, and modulated into a digital signal s4. The digital signal s4 is stored in the shift register (8 × nbit) 106 at any time in synchronization with the timing signal s2. As the data stored in the shift register 106, digital data for one horizontal pixel is stored and at the same time as timing s.
At 1 the data is taken into the one-line memory 107. The data stored in the one-line memory 107 is supplied to the modulation signal generator 108 at timing s1.

The modulation signal generator 108 includes n counter circuits C1 to Cn. FIG. 2 is a diagram for explaining this counter circuit.

In FIG. 2A, the one-line memory 10
The 8 × n-bit digital signal s6 supplied from 7 is
The signals are input to counter circuits C1 to Cn in n columns. The timing signals s1 and s3 are added to the counter circuits C1 to Cn. When the signal s1 is applied, the counter circuit C1 starts counting from the value given by the digital signal s6 based on the signal s3 and counts up to 255 at the same time. , A preset type in which the output changes from low to high.

This timing is shown in FIG. That is, for example, if the signal s6 is 0xff, counting starts from this value, that is, 255,
Since it has reached 5, the output signal s7 immediately changes to High, and then changes to Low when the timing signal s1 is applied next. Further, for example, if the value of the signal s6 is 0x40, starting from 0x40, that is, 64, from the application of the timing signal s1, counting up to 255 in synchronization with the signal s3, the output signal s7 is changed to High, and the next timing signal is set. It returns to Low by applying s1. By doing this,
The output signal s7 corresponding to the image signal can be obtained as a signal whose rising is shifted for each value of each pixel and whose falling is synchronized.

As described above, the modulation control signal s7 having a pulse width corresponding to the image signal is output from the modulation signal generator 108.
Is output and supplied to the last-stage transistors Tr1 to Trn. The transistors Tr1 to Trn are turned on with the modulation control signal s7, and the output is a modulation signal s having a pulse width corresponding to the image signal as shown in FIG.
8 is output.

Further, as shown in FIG.
There is a v terminal, and a high voltage Va is applied between the face plate of the display panel and the rear plate (element substrate).

On the scanning signal side, there is an m-bit ring counter that shifts in synchronization with the timing signal s1 supplied from the timing control circuit. The output of the ring counter is connected to the gates of the transistors Ts1 to Tsm in m rows, and the transistors that are turned on in synchronization with the timing s1 shift. As a result, a scanning signal s9 as shown in FIG. 3 is output to the row wiring.

Although the above description has been made in the case of the non-interlace, it is needless to say that the same effect can be obtained also in the case of the interlace since the modulation signal can be created by using the same means. The counter circuit of the modulation signal generator 108 may have any configuration as long as the above operation, that is, the pulse width modulation is performed, the timing of the modulation signal is shifted so that the rising of the modulation signal is not synchronized. It does not matter.

When the display panel was actually driven by the configuration of the drive circuit described above, ringing at the rising edge of the modulation signal, which was observed in the conventional drive system, was hardly observed. Specifically, conventionally, when the peak value of the driving voltage is 7 V and the selection voltage (peak value) of the scanning signal is -7 V as shown in FIG. 23, ringing of about 1 V at the maximum is synchronized with the rise of the modulation signal. Although a certain voltage was applied to the cold cathode element, the ringing at the time of the rising was hardly observed by adopting the above-described configuration (FIG. 4).

Although ringing at the time of falling as shown in FIG. 4 remains, the characteristics of the cold-cathode device according to the present embodiment described later do not damage the device or have an adverse effect due to an unexpected memory effect.

As described above, by scanning each element of the display panel 110 row by row and applying a modulation signal, an image corresponding to an input image signal can be displayed.

Next, the display panel 110 will be described in detail. <Structure of Display Panel> Next, the structure and manufacturing method of the display panel 110 of the image display device to which the present invention is applied will be described with reference to specific examples.

FIG. 5 is a perspective view of the display panel in the present embodiment, in which a part of the panel is cut away to show the internal structure.

In the figure, 1005 is a rear plate, 1006
Is a side wall, and 1007 is a face plate. These members 1005 to 1007 form an airtight container for maintaining the inside of the display panel at a vacuum. When assembling an airtight container, it is necessary to seal the joints of each member to maintain sufficient strength and airtightness.For example, apply frit glass to the joints, and in air or nitrogen atmosphere, Sealing was achieved by baking at 400 to 500 degrees for 10 minutes or more. A method of evacuating the inside of the airtight container to a vacuum will be described later.

The rear plate 1005 has a substrate 1001
Is fixed, but the cold cathode device 1002 is provided on the substrate.
N × M are formed. 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, it is desirable to set N = 3000 and M = 1000 or more. In the present embodiment, N = 3072 and M = 1024. The N × M cold cathode elements are arranged in a simple matrix by M row-directional wirings 1003 and N column-directional wirings 1004. 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 substrate 1001 of the multi-electron beam source is fixed to the rear plate 1005 of the airtight container.
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 separately applied in a stripe shape as shown in FIG. 6A, for example, and a black conductor 1010 is 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. Black conductor 1
For 010, graphite was used as a main component, but other materials may be used as long as they are suitable for the above purpose.

The method of applying the phosphors of the three primary colors is not limited to the stripe arrangement shown in FIG. 6A, but may be, for example, a delta arrangement as shown in FIG. Other arrangements may be used.

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

Also, a metal back 1009 known in the field of CRT is provided on the surface of the fluorescent film 1008 on the rear plate side.
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.
Note that when a fluorescent material for low voltage is used for the fluorescent film 1008, the metal back 1009 is not used.

Although not used in the present embodiment, for the purpose of applying an acceleration voltage and improving the conductivity of the fluorescent film, a transparent material made of, for example, ITO is provided between the face plate substrate 1007 and the fluorescent film 1008. Electrodes may be provided.

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

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

The basic structure and manufacturing method of the display panel according to the embodiment of the present invention have been described above. <Method of Manufacturing Multi-Electron Beam Source> Next, a method of manufacturing the multi-electron beam source used in the display panel of the above embodiment will be described. The material, shape, and manufacturing method of the cold cathode device are not limited as long as the multi-electron beam source used for the image display device of the present invention is an electron source in which cold cathode devices are arranged in a simple matrix. Therefore, for example, a cold cathode device such as a surface conduction type emission device, an FE type, or an MIM type can be used.

However, in a situation where a display device having a large display screen and an inexpensive display device is required, among these cold cathode devices, a surface conduction type emission device is particularly preferable. That is, in the FE type, since the relative position and shape of the emitter cone and the gate electrode greatly affect the electron emission characteristics, extremely high-precision manufacturing technology is required, 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. On the other hand, since the surface conduction electron-emitting device has a relatively simple manufacturing method, it is easy to increase the area and reduce the manufacturing cost. In addition, the inventors have found that among the surface conduction electron-emitting devices, those in which the electron-emitting portion or its peripheral portion is formed of a fine particle film have particularly excellent electron-emitting characteristics and can be easily manufactured. Therefore, it can be said that it is most suitable for use in a multi-electron beam source of a high-luminance, 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. (Suitable device configuration and manufacturing method of surface conduction type emission device) The typical configuration of the surface conduction type emission device in which the electron-emitting portion or its peripheral portion is formed of a fine particle film is a flat type or a vertical type.
Kinds are given. (Flat-type surface conduction electron-emitting device) First, an element configuration and a manufacturing method of a flat-type surface conduction electron-emitting device will be described. FIG. 7 is a plan view (a) and a cross-sectional view (b) for describing the configuration of a planar surface conduction electron-emitting device. In the figure, 1101 is a substrate, 1102 and 1103 are device electrodes, 1104 is a conductive thin film, 1105 is an electron-emitting portion formed by energization forming, and 1113 is a thin film formed by energization activation.

As the substrate 1101, for example, various glass substrates such as quartz glass and blue plate glass, various ceramics substrates such as alumina, or an insulating layer made of, for example, SiO 2 is laminated on the various substrates described above. Substrate or the like can be used.

The element electrodes 1102 and 1103 provided on the substrate 1101 so as to be parallel to the substrate surface are formed of a conductive material. For example, N
i, Cr, Au, Mo, W, Pt, Ti, Cu, Pd,
Materials may be appropriately selected and used from metals such as Ag and the like, alloys of these metals, metal oxides such as In 2 O 3 —SnO 2, and semiconductors such as polysilicon. To form the electrodes, for example, film forming technology such as vacuum evaporation and photolithography,
Although it can be easily formed by using a combination of patterning techniques such as etching, it may be formed by other methods (for example, printing technique).

The shapes of the device electrodes 1102 and 1103 are appropriately designed according to the application purpose of the electron-emitting device.
Generally, the electrode spacing L is usually designed by selecting an appropriate 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.

Further, a fine particle film is used for the portion of 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 fine particles are spaced apart, a structure in which the fine particles are adjacent to each other, or a structure in which the fine particles overlap each other is observed.

The particle size of the fine particles used in the fine particle film is in the range of several Angstroms to several thousand Angstroms, and preferably in the range of 10 Angstroms to 200 Angstroms. 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.
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. 7, the overlapping manner is such that the substrate, the device electrode, and the conductive thin film are stacked in this order from the bottom, but in some cases, the substrate, the conductive thin film, and the device electrode are stacked in this order from the bottom. I can't wait.

The electron-emitting portion 1105 is a crack-like portion formed in a part of the conductive thin film 1104, and has an 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 size of several Angstroms to several hundred Angstroms may be arranged in the crack. Since it is difficult to accurately and accurately show the actual position and shape of the electron-emitting portion, they are schematically shown in FIG.

The thin film 1113 is a thin film made of carbon or a carbon compound 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 made of any one of single-crystal graphite, polycrystalline graphite, and amorphous carbon, or a mixture thereof, and has a thickness of 500 [Å] or less, but 300 [Å] or less. Is more preferred.

Since it is difficult to accurately show 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.

The basic structure of the preferred element has been described above. In the embodiment, the following element is used.

That is, blue glass was used for the substrate 1101, and Ni thin films were used for the device electrodes 1102 and 1103. The thickness d of the device electrode was 1000 [angstrom], and the electrode interval L was 2 [micrometer].

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

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

1) First, as shown in FIG. 8A, device electrodes 1102 and 1103 are formed on a substrate 1101.

Before forming, the substrate 1
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. Thereafter, the deposited electrode material is patterned by using a photolithography / etching technique, and a pair of device electrodes (1102 and 1102) shown in FIG.
Form 3).

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

In the formation, first, an organic metal solution is applied to the substrate (a), dried, heated and baked to form a fine particle film, and then patterned into a predetermined shape by photolithography and etching. . here,
The 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, in this embodiment, Pd is used as a main element. In the embodiment, a dipping method is used as a coating method, but other methods such as a spinner method and a spray method may be used.

As a method for forming a conductive thin film made of a fine particle film, a method other than the method of applying the organometallic solution used in the present embodiment, for example, a vacuum evaporation method, a sputtering method, or a chemical vapor deposition method Method may be used.

3) Next, as shown in FIG. 10C, a forming power supply 1110 supplies the device electrodes 1102 and 1102 with each other.
3, an appropriate voltage is applied, and an energization forming process is performed to form the electron-emitting portion 1105.

[0110] The energization forming treatment is to energize the conductive thin film 1104 made of a fine particle film, to appropriately break, deform, or alter a part of the conductive thin film 1104, thereby changing the structure to a structure suitable for emitting electrons. This is the process that causes 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 electrical resistance measured between the device electrodes 1102 and 1103 is significantly increased after the formation of the electron emission portions 1105 as compared to before the formation.

FIG. 9 shows an example of an appropriate voltage waveform applied from the forming power supply 1110 in order to explain the energization method in more detail. When forming a conductive thin film made of a fine particle film, a pulse-like voltage is preferable. In the case of this embodiment, a triangular wave pulse having a pulse width T1 is continuously generated at a pulse interval T2 as shown in FIG. Was applied. At that time, the peak value Vpf of the triangular wave pulse was sequentially increased. Also, monitor pulses Pm for monitoring the state of formation of the electron-emitting portion 1105 are inserted at appropriate intervals between the triangular-wave pulses, and the current flowing at that time is measured by the ammeter 1.
It was measured at 111.

In the embodiment, for example, in a vacuum atmosphere of about 10 −5 [torr], for example, the pulse width T1 is 1 [millisecond], the pulse interval T2 is 10 [millisecond], and the peak value Vpf is The voltage was increased by 0.1 [V] for each pulse. Then, the monitor pulse Pm was inserted at a rate of one every time five triangular waves were applied. The monitor pulse voltage Vpm was set to 0.1 [V] so as not to adversely affect the forming process. Then, when the electric resistance between the element electrodes 1102 and 1103 becomes 1 × 10 6 [ohm], that is, the current measured by the ammeter 1111 when the monitor pulse is applied becomes 1 × 10 −7 [A] or less. At this stage, the energization related to the forming process was terminated.

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

4) Next, as shown in FIG. 8D, an appropriate voltage is applied between the element electrodes 1102 and 1103 from the activating power supply 1112, and the energizing activation process is performed to perform electron emission. Improve characteristics.

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 a 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 minus the fourth power to 1
By applying a voltage pulse periodically in a vacuum atmosphere within the range of 0 to the fifth power [torr], carbon or a carbon compound originating from an organic compound existing in the vacuum atmosphere is deposited. The deposit 1113 is any 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. 10A 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 applying a rectangular wave of a constant voltage periodically, but 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.

An anode electrode 1114 shown in FIG. 8D is used to capture an emission current Ie emitted from the surface conduction electron-emitting device, and is connected to a DC high voltage power supply 1115 and an ammeter 1116. Note that 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 used.
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 substantially saturated, the application of the voltage from the activation power supply 1112 is stopped, and the energization activation process ends.

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, the conditions should be changed accordingly. desirable.

As described above, the planar surface conduction electron-emitting device shown in FIG. 8E was manufactured. (Vertical type surface conduction electron-emitting device) Next, another typical structure of a surface conduction electron-emitting device in which an electron-emitting portion or its periphery is formed of a fine particle film, that is, the structure of a vertical surface conduction electron-emitting device Will be described.

FIG. 11 is a schematic cross-sectional view for explaining the basic structure of a vertical type. In FIG.
202 and 1203 are device electrodes, 1206 is a step forming member, 1204 is a conductive thin film using a fine particle film, 1205
Are electron-emitting portions formed by an energization forming process;
213 is a thin film formed by the activation process.

The difference between the vertical type and the flat type described above is that one of the device electrodes (1202) is provided on the step forming member 1206, and the conductive thin film 1204 is provided on the side surface of the step forming member 1206. It is in the point of coating. 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
For 204, the materials listed in the description of the planar type can be similarly used. For the step forming member 1206, an electrically insulating material such as SiO2 is used.

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

1) First, as shown in FIG. 12A, an element electrode 1203 is formed on a substrate 1201.

2) Next, as shown in FIG. 13B, an insulating layer for forming a step forming member is laminated. The insulating layer may be formed by laminating, for example, SiO2 by a sputtering method. However, another film forming method such as a vacuum evaporation method or a printing method may be used.

3) Next, as shown in FIG. 13C, an element electrode 1202 is formed on the insulating layer.

4) Next, as shown in FIG. 14D, a part of the insulating layer is removed by using, for example, an etching method to expose the element electrode 1203.

5) Next, as shown in FIG. 14E, 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. A process similar to the planar energization forming process described with reference to FIG. 8C may be performed.

7) Next, as in the case of the flat type, a current activation process is performed to deposit carbon or a carbon compound near the electron emitting portion. The same process as the planar energization activation process described with reference to FIG. 8D may be performed.

As described above, the vertical surface conduction electron-emitting device shown in FIG. 12F was manufactured. <Characteristics of surface conduction electron-emitting device used in display device>
The device configuration and manufacturing method of the planar and vertical surface conduction electron-emitting devices have been described. Next, the characteristics of the devices used in the display device will be described.

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

The element used 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
When a voltage of the above magnitude is applied to the element, the emission current Ie sharply increases. On the other hand, at a voltage lower than the threshold voltage Vth, the emission current Ie is hardly detected.

That is, the non-linear element has 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.

In addition, by using the second characteristic or the third characteristic, the light emission luminance can be controlled, so that a gradation display can be performed.

Here, if the control circuit of the display panel is constructed as shown in FIG. 1, even if ringing occurs at the time of falling of the element applied voltage as shown in FIG. Since the threshold voltage is not reached due to one characteristic, the memory effect is not exerted on the element. <Structure of a multi-electron beam source in which a large number of elements are arranged in a simple matrix) Next, a structure of a multi-electron beam source in which the above-described surface conduction electron-emitting devices are arranged on a substrate and arranged in a simple matrix will be described.

FIG. 14 is a plan view of the multi-electron beam source used for the display panel of FIG. On the substrate, surface conduction type emission elements similar to those shown in FIG. 7 are arranged, and these elements are wired in a simple matrix by row-direction wiring electrodes 1003 and column-direction wiring electrodes 1004. An insulating layer (not shown) is formed between the row-directional wiring electrodes 1003 and the column-directional wiring electrodes 1004 where they intersect, so that electrical insulation is maintained.

FIG. 15 is a sectional view taken along the line AA ′ of FIG.
Shown in

Incidentally, the multi-electron source having such a structure is as follows.
After previously forming a row direction wiring electrode 1003, a column direction wiring electrode 1004, an interelectrode insulating layer (not shown), and a device electrode of a surface conduction type emission device and a conductive thin film 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. 16 shows image information provided from various image information sources such as television broadcasting on a display panel using the surface conduction electron-emitting device according to the above-described manufacturing method as an electron beam source. FIG. 2 is a diagram illustrating an example of a multi-function display device configured to be able to be used.

In the figure, reference numeral 110 denotes a display panel, 21
Reference numeral 01 denotes a display panel driving circuit, which corresponds to blocks 101 to 109 in FIG. 2102, a display controller; 2103, a multiplexer; 2104, a decoder; 2105, an input / output interface circuit;
106 is a CPU, 2107 is an image generation circuit, 2108, 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 present display device receives a signal containing both video information and audio information, such as a television signal, it naturally reproduces the audio simultaneously with the display of the video. Descriptions of circuits, speakers, and the like relating to reception, separation, reproduction, processing, storage, and the like of audio information that are not directly related to the features of the invention will be omitted.

Hereinafter, the function of each section will be described 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 format of the received TV signal is not particularly limited, and may be, for example, various systems such as the NTSC system, the PAL system, and the SECAM system. Further, a TV signal (for example, a so-called high-definition TV including the MUSE system) composed of a larger number of scanning lines than the above is suitable for taking advantage of the display panel suitable for a large area and a large number of pixels. 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 wired transmission system such as a coaxial cable or an optical fiber. Similarly to 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.

The image input interface circuit 21
A circuit 11 captures 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 an 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.
04 is output.

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 input from outside via the input / output interface circuit 2105, or a CPU.
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 the present circuit is output to the decoder 2104. In some cases, the display image data can be input / output to / from an external computer network or a printer via the input / output interface circuit 2105.

The CPU 2106 mainly carries out 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, and image signals to be displayed on the display panel are appropriately selected or combined. In this case, a control signal is generated for the display panel controller 2102 in accordance with an image signal to be displayed, and a display frequency, a scanning method (for example, interlaced or non-interlaced), and the number of scanning lines per screen are displayed. The operation of the device is appropriately controlled.

Further, image data and character / graphic information are directly output to the image generation circuit 2107, or an external computer or memory is accessed via the input / output interface circuit 2105 to access the image data or character / graphic information. Enter graphic information.

The CPU 2106 may, of course, be involved in work for other purposes. 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, the computer may be connected to an external computer network via the input / output interface circuit 2105 as described above, and operations such as numerical calculations may be performed in cooperation with external devices.

The input unit 2114 is connected to 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.

The decoder 2104 is provided with the 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 for handling television signals that require an image memory when performing inverse conversion, such as the MUSE method. In addition, the provision of the image memory facilitates the display of a still image, or cooperates with the image generation circuit 2107 and the CPU 2106 to perform image processing and editing including culling, interpolation, enlargement, reduction, and synthesis. This is because there is an advantage that it can be easily performed.

The multiplexer 2103 is connected to 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 television. .

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

Further, as a signal related to the display panel driving method, a signal for controlling, for example, a screen display frequency and a scanning method (for example, interlaced or non-interlaced) is output to the driving circuit 2101.

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

Further, the driving circuit 2101 is connected to the display panel 1.
10 is a circuit for generating a drive signal to be applied to 10
It operates based on an image signal input from the multiplexer 2103 and a control signal input from the display panel controller 2102.

The function of each section has been described above. With the configuration illustrated in FIG. 16, in this display device, image information input from various image information sources is displayed on the display panel 1.
10 can be displayed.

That is, various image signals including television broadcasting 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, an image is displayed on display panel 110. These series of operations are performed by CP
It is totally controlled by U2106.

In the present display device, the image memory built in the decoder 2104, the image generation circuit 21
07 and the CPU 2106 involve not only displaying a selected one of a plurality of pieces of image information but also enlarging, reducing,
It is also possible to perform image processing such as rotation, movement, edge enhancement, thinning, interpolation, color conversion, image aspect ratio conversion, etc., and image editing such as synthesis, deletion, connection, replacement, insertion, etc. is there. Although not specifically mentioned in the description of the present embodiment, a dedicated circuit for processing and editing audio information may be provided as in the above-described image processing and image editing.

Therefore, the present display device is a television broadcast display device, a video conference terminal device, 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 can be equipped with the functions of a game machine etc. by one unit, and has a very wide application range for industrial or consumer use.

FIG. 16 shows only an example of a configuration of a display device using a display panel using a surface conduction electron-emitting device as an electron beam source, and the present invention is not limited to this. Needless to say. For example, FIG.
Circuits related to functions that are not necessary 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 made thin, the depth of the entire display device can be reduced. In addition, the display panel using surface conduction electron-emitting devices as the electron beam source can easily enlarge the screen, and has high brightness and excellent viewing angle characteristics. It is possible to display well.

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.

[0178]

As described above, according to the present invention, when a display panel to which a cold cathode device is applied is driven, an overvoltage due to ringing appearing in a driving waveform is prevented from being applied, thereby deteriorating the device. Or destruction can be prevented. In addition, it is possible to prevent an unexpected memory effect from occurring due to ringing, and to prevent display disturbance due to a shift in element characteristics due to the unexpected memory effect.

[0179]

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an image display circuit driving device used in an embodiment.

FIG. 2 is a schematic diagram of a counter circuit used in the embodiment.

FIG. 3 is a time chart of a pulse width modulation drive signal described in the embodiment.

FIG. 4 is a diagram of a driving waveform of a pulse width modulation signal used in the embodiment.

FIG. 5 is a perspective view of the image display device according to the embodiment of the present invention, in which a part of a display panel is cut away.

FIG. 6 is a plan view illustrating a phosphor array of a face plate of the display panel.

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

FIG. 8 is a cross-sectional view showing a manufacturing process of the planar type surface conduction electron-emitting device.

FIG. 9 is a diagram of an applied voltage waveform in the energization forming process.

FIG. 10 shows an applied voltage waveform (a) in the energization activation process;
It is a figure of change (b) of emission current Ie.

FIG. 11 is a sectional view of a vertical surface conduction electron-emitting device used in the embodiment.

FIG. 12 is a sectional view showing a manufacturing process of the vertical surface conduction electron-emitting device.

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

FIG. 14 is a plan view of a substrate of the multi-electron beam source used in the embodiment.

FIG. 15 is a partial cross-sectional view of the substrate of the multi-electron beam source used in the embodiment.

FIG. 16 is a block diagram of a multi-function image display device using the image display device according to the embodiment of the present invention.

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

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

FIG. 19 is a diagram of an example of a conventionally known MIM.

FIG. 20 is a diagram illustrating a wiring method of an electron-emitting device in which a problem that the inventors have attempted has occurred.

FIG. 21 is a diagram for explaining a conventional pulse width modulation driving method.

FIG. 22 is a diagram for explaining a conventional pulse width modulation driving method.

FIG. 23 is a diagram for explaining a problem.

FIG. 24 is a diagram for explaining a problem.

FIG. 25 is a diagram for explaining a problem.

Continuation of the front page (56) References JP-A-6-289814 (JP, A) JP-A-7-177446 (JP, A) JP-A-52-56232 (JP, A) JP-A-63-14129 (JP, A) , A) JP-A-5-249920 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G09G 3/00-3/38 G02F 1/133 505-580 H04N 5/66- 5/74 H01J 1/30 H01J 29/98 H01J 31/12

Claims (15)

(57) [Claims] 1. A multi-electron beam source in which surface conduction electron-emitting devices that emit electrons in an amount corresponding to a voltage application time are arranged in a matrix. On the other hand, a modulation signal generating means for generating a modulation signal of a predetermined wave height of a time width corresponding to a value of an image signal for each surface conduction type emission element by synchronizing a rear end of the modulation signal, based on the generated modulation signals by means, it said has a drive means for each surface conduction electron-emitting devices to drive while scanning each row, the surface conduction electron-emitting device, if a pulse voltage is applied , Applied earlier
Pulse voltage with a voltage value greater than the
Characteristic curve of applied voltage and emission current shifts,
A multi-electron beam source having a memory characteristic whose characteristic curve is stored . 2. The apparatus according to claim 1, wherein said modulated signal generating means includes sampling means for sampling an image signal, and means for determining a rising timing of the modulated signal according to a value of the sampled image signal. A multi-electron beam source according to claim 1. 3. The determining means includes counter means for setting a maximum value sampleable by the sampling means as the maximum value, and counting the image signal sampled by the sampling means as an initial value by the counter means. 3. The multi-electron beam source according to claim 2, wherein the timing when the maximum value is reached is determined as the rising timing of the modulation signal. 4. The driving means according to claim 1, wherein said driving means comprises a surface conduction type discharge for each row.
Out Select element group, the scanning signal applying means for applying a pulse signal of a predetermined peak value and a predetermined width in the surface conduction electron-emitting device <br/> groups in a selected row, each surface conduction type in the selected row Release
4. The multi-electron beam source according to claim 1, further comprising a modulation signal applying unit that applies a signal generated by the modulation signal generating unit to an output element . 5. A multi-electron beam source comprising a matrix of surface conduction electron-emitting devices that emit electrons in an amount corresponding to a voltage application time, wherein: a sampling means for sampling an image signal; A counter for setting the maximum value that can be sampled by the means to the maximum value, starting counting by the counter means with the value of the image signal sampled by the sampling means as an initial value, and determining the timing when the maximum value is reached by a pulse signal. Deciding means for deciding as a rising timing, modulating signal producing means for producing a modulated pulse signal which rises at the timing decided by the deciding means and falls at a predetermined timing, and selects a surface conduction type emission element group for each row. Scanning of the surface conduction electron-emitting device group of the selected row with a predetermined peak value and a predetermined width Scanning signal applying means for applying a pulse signal, and modulation signal applying means for applying a modulation pulse signal generated by the modulation signal generating means to each surface conduction type emission element in each row, When the pulse voltage is applied, the type emission element is applied before
Pulse voltage with a voltage value greater than the
Characteristic curve of applied voltage and emission current shifts,
A multi-electron beam source having a memory characteristic whose characteristic curve is stored . 6. A light emitting means for arranging surface conduction electron-emitting devices for emitting an amount of electrons corresponding to a voltage application time in a matrix, and for emitting light according to the amount of electrons emitted from each surface conduction electron-emitting device. A display device for visualizing an image by: A modulation signal of a predetermined wave height having a time width corresponding to a value of an image signal for each surface conduction type emission element group for one row of surface conduction type emission element groups, Modulation signal generation means for synchronizing and generating the rear end of the modulation signal; and drive means for driving the surface conduction electron-emitting device while scanning each row based on the modulation signal generated by the modulation signal generation means. When a pulse voltage is applied, the surface conduction electron-emitting device is applied before the pulse voltage is applied.
Pulse voltage with a voltage value greater than the
Then, the characteristic curve of applied voltage and emission current shifts,
A display device having a memory characteristic in which the characteristic curve is stored . Wherein said modulating signal generating means, according to claim, characterized in that it comprises a sampling means for sampling an image signal, and means for determining the rising timing of the modulation signal in accordance with the value of the sampled image signal 6 The display device according to claim 1. 8. The determining means includes counter means for setting a maximum value which can be sampled by the sampling means to the maximum value, and counting the image signal sampled by the sampling means as an initial value by the counter means. 8. The display device according to claim 7 , wherein a timing when the maximum value is reached is determined as a rising timing of the modulation signal. 9. The driving device according to claim 1, wherein the driving means comprises a surface conduction type discharge for each row.
Out Select element group, the scanning signal applying means for applying a pulse signal of a predetermined peak value and a predetermined width in the surface conduction electron-emitting device <br/> groups in a selected row, each surface conduction type in the selected row Release
9. The display device according to claim 6 , further comprising a modulation signal application unit that applies a signal generated by the modulation signal generation unit to an output element . 10. The image signal is a color image signal,
7. The apparatus according to claim 6, wherein said modulation signal generating means generates a modulation signal for each color signal, and said light emitting means includes a phosphor in which phosphors of three primary colors of red, green and blue are arranged in a predetermined format.
10. The display device according to any one of 9 to 9 . 11. A light emitting means for arranging surface conduction electron-emitting devices for emitting an amount of electrons corresponding to a voltage application time in a matrix, and for emitting light according to the amount of electrons emitted from each surface conduction electron-emitting device. A display device that visualizes an image by: a sampling unit that samples an image signal; and a counter that sets a maximum value that can be sampled by the sampling unit to the maximum value. Determining means for starting counting by the counter means as an initial value and determining a timing when the maximum value is reached as a rising timing of the pulse signal; a modulation pulse rising at the timing determined by the determining means and falling at a predetermined timing A modulation signal generating means for generating a signal, and a surface conduction emission element for each row. Scanning signal applying means for selecting a group and applying a scanning pulse signal having a predetermined peak value and a predetermined width to the surface conduction type emission element group of the selected row; and the modulation signal for each surface conduction type emission element in each row. Modulating signal applying means for applying the modulated pulse signal generated by the generating means, wherein the surface conduction type emission element is applied before a pulse voltage is applied.
Pulse voltage with a voltage value greater than the
Characteristic curve of applied voltage and emission current shifts,
A display device having a memory characteristic whose characteristic curve is stored . 12. A method for controlling a multi-electron beam source, comprising a plurality of surface conduction electron-emitting devices which emit electrons in an amount corresponding to a voltage application time, wherein the surface conduction electron-emitting devices are arranged in a matrix.
The output element is marked before the pulse voltage is applied.
A pulse voltage with a voltage value greater than the applied voltage value is applied
Characteristic curve of applied voltage and emission current shifts
And has a memory characteristic whose characteristic curve is stored.
Cage, to the surface conduction electron-emitting device group for one line, a modulation signal of a predetermined pulse height of time width corresponding to the value of the image signal for each surface conduction electron-emitting device, to synchronize the trailing edge of the modulated signal And a driving step of driving the surface conduction electron-emitting device while scanning the row by row based on the modulation signal generated by the modulation signal generating means. Control method of electron beam source. Wherein said modulation signal generating step, claim, characterized in that it comprises a sampling step of sampling the image signal, and determining the rising timing of the modulation signal in accordance with the value of the sampled image signals 12
3. The method for controlling a multi-electron beam source according to claim 1. 14. The determining step includes a counter that sets a maximum value that can be sampled in the sampling step to the maximum value, and starts counting by the counter with an image signal value sampled in the sampling step as an initial value. 14. The method according to claim 13 , wherein the timing when the maximum value is reached is determined as the rising timing of the modulation signal. 15. The method according to claim 15, wherein the driving step includes a surface conduction type for each row.
Select the emission element group and select the surface conduction type emission element in the selected row.
A scanning signal applying step of applying a pulse signal having a predetermined peak value and a predetermined width to the child group, and each surface conduction type in a selected row.
The method of driving a multi-electron beam source according to any one of claims 12 to 14 , further comprising a step of applying a modulation signal generated by the modulation signal generation step to an emission element .