JP2000242220A - Device and method for manufacturing electron source, and electron source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reduction with time and stability of an emission current of an electron source by applying a voltage to an electron emission element from the row direction wiring of the electron source when a preliminary drive voltage is applied to all elements of the electron source, increasing the power thrown into the electron source accompanying the application of the voltage at every prescribed time and applying the preliminary drive voltage to all elements on the electron source. SOLUTION: A relation between the current I and the voltage V in a voltage range accompanied with electron emission from the electron emission element is expressed by a function of I=f(V), and when f'(V) is defined as a differential coefficient of f(V) in the voltage V, after the drive is performed beforehand with the preliminary drive voltage of V1, the regular drive is performed with the voltage V2 becoming f(V1)/(V1.f'(V1)--2f(V1))>f(V2)/(V2.f'(V2)-2f(V2)). For that, the preliminary drive voltage V1 is applied to all elements of the electron source arranging plural electron emission elements on a substrate in matrix by row direction wiring 4002 and column direction wiring 4003.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for manufacturing an electron source having a large number of electron-emitting devices.

[0002]

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

As an example of the FE type, see, for example, P. D
yke & W. W. Dolan, "Field em
issue ", Advance in Electr
on Physics, 8, 89 (1956) or C.I. A. Spindt, "Physical pr
operations of thin-film figure
ld emission cathodes with
molybdenium cones ", J. App.
l. Phys. , 47, 5248 (1976).

As an example of the MIM type, for example,
C. A. Mead, “Operation of tu
nnel-emission Devices, J. et al. A
ppl. Phys. , 32, 646 (1961).

Further, as a surface conduction type emission device, for example, M.S. I. Elinson, Radio Eng. E
electron Phys. , 10, 1290, (19
65) and other examples described later.

[0006] 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 the O ₂ thin film, those using the Au thin film [G. Dittmer: "Thin Solid Fil
ms ", 9,317 (1972)] and In ₂ O ₃ / S
nO ₂ thin film [M. Hartwell and
C. G. FIG. Fonstad: "IEEE Trans.
ED Conf. , 519 (1975)] and those using carbon thin films [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1,
No. 22 (1983)].

[0007] As a typical example of the element configuration of these surface conduction electron-emitting devices, FIG. Hartwel
1 shows a plan view of an element according to the present invention. In FIG.
Reference numeral 1 denotes a substrate, and reference numeral 3004 denotes a conductive thin film made of a metal oxide formed by sputtering. The conductive thin film 3004 is formed in an H-shaped planar shape as shown. An electron emission portion 3005 is formed by subjecting the conductive thin film 3004 to an energization process called energization forming described later. The interval L in the figure is 0.5 to 1 [mm], and W is
It is set at 0.1 [mm]. For convenience of illustration, the electron-emitting portion 3005 is shown in a rectangular shape at the center of the conductive thin film 3004, but this is a schematic shape, and the position and shape of the actual electron-emitting portion are faithfully represented. Not necessarily. M. In the above-described surface conduction electron-emitting device, including the device by Hartwell et al., It is general to form an electron-emitting portion 3005 by subjecting the conductive thin film 3004 to an energization process called energization forming before electron emission. It was a target. That is, the energization forming means applying a constant DC voltage to both ends of the conductive thin film 3004 or applying a DC voltage which is stepped up at a very slow rate of about 1 V / min. The electron-emitting portion 300 in an electrically high-resistance state by locally destroying, deforming, or altering the conductive thin film 3004
5 is formed. Note that a part of the conductive thin film 3004 that is locally broken, deformed, or altered includes
Cracks occur. When an appropriate voltage is applied to the conductive thin film 3004 after the energization forming, electrons are emitted in the vicinity of the crack.

As described above, when forming the electron-emitting portion of the surface conduction electron-emitting device, a current is applied to the conductive thin film to locally break, deform or alter the thin film, thereby forming a crack ( Energization forming process). Thereafter, by further performing the activation process, it is possible to greatly improve the electron emission characteristics.

That is, the energization activation process is an energization form.
This is a process of energizing the electron-emitting portion formed by the trimming process under appropriate conditions and depositing carbon or a carbon compound in the vicinity thereof. For example, an organic substance having an appropriate partial pressure exists, and the total pressure is 10 ⁻⁴ to 10 ⁻⁵ [Torr].
By applying a voltage pulse periodically in the vacuum atmosphere, any one of monocrystalline graphite, polycrystalline graphite, and amorphous carbon is formed in the vicinity of the electron emitting portion.
Alternatively, the mixture is deposited to a thickness of 500 [Å] or less. However, it is needless to say that this condition is only an example and should be appropriately changed depending on the material and shape of the surface conduction electron-emitting device.

By performing such processing, the emission current at the same applied voltage can be typically increased by 100 times or more as compared with immediately after the energization forming. It is desirable to reduce the partial pressure of the organic substance in the vacuum atmosphere after the completion of the activation. This is called a stabilization step.

The above-mentioned surface conduction electron-emitting device has an advantage that a large number of devices can be formed over a large area since it has a simple structure and is easy to manufacture. Therefore, for example, as disclosed in Japanese Patent Application Laid-Open No. 64-31332 by the present applicant, a method for arranging and driving a large number of elements has been studied.

With respect to 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, and a charged beam source have been studied. In particular, as an application to an image display device, for example, U.S. Pat.
As disclosed in SP5, 066, 883 and JP-A-2-257551, an image display device using a combination of a surface conduction electron-emitting device and a phosphor that emits light upon irradiation with an electron beam has been studied. An image display device using a combination of a surface conduction emission 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 excellent in that it is a self-luminous type and does not require a backlight and has a wide viewing angle.

[0013]

SUMMARY OF THE INVENTION The present applicants have attempted to produce surface conduction type emission devices having various materials, manufacturing methods and structures, including those described in the above-mentioned prior art. Furthermore, research has been conducted on a multi-beam electron source in which a large number of surface conduction electron-emitting devices are arranged, and on an image display device using the multi-beam electron source.

The present applicants have attempted to manufacture a multi-electron beam source by, for example, an electrical wiring method shown in FIG. That is, it is a multi-electron beam source in which a large number of surface conduction emission devices are two-dimensionally arranged and these devices are wired in a matrix as shown in the figure. In the figure, 4001 schematically shows a surface conduction electron-emitting device, 4002 shows a row direction wiring, and 4003 shows a column direction wiring. Row direction wiring 4
002 and the column wiring 4003 actually have a finite electrical resistance, but in the drawing, the wiring resistance 4
004 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 is displayed. Elements that are sufficient for displaying are arranged and wired.

In a multi-electron beam source in which surface conduction electron-emitting devices are arranged in a simple matrix, an appropriate electric signal is applied to the row wiring 4002 and the column wiring 4003 in order to output a desired electron beam. For example, to drive a surface conduction electron-emitting device of an arbitrary row in a matrix, a selection voltage Vs is applied to a row-directional wiring 4002 of a selected row, and at the same time, a row-directional wiring 4002 of a non-selected row is applied.
Is applied with a non-selection voltage Vns. In synchronization with this, a drive voltage Ve for outputting an electron beam is applied to the column wiring 4003. According to this method, the wiring resistance 4004
Neglecting the voltage drop caused by Ve and Vs, the voltage of Ve−Vs is applied to the surface conduction type emission element of the selected row, and Ve−V is applied to the surface conduction type emission element of the non-selected row.
A voltage of ns is applied. If Ve, Vs, and Vns are set to voltages of appropriate magnitudes, an electron beam of a desired intensity should be output only from the surface conduction electron-emitting device of the selected row, and a different driving voltage is applied to each of the column wirings. If Ve is applied, each of the elements in the selected row should output a different intensity electron beam. Further, since the response speed of the surface conduction electron-emitting device is high, if the length of time for applying the driving voltage Ve is changed, the length of time for outputting the electron beam can be changed. Therefore, various applications are considered for the multi-electron beam source in which the surface conduction electron-emitting devices are arranged in a simple matrix.
For example, if a voltage signal corresponding to image information is appropriately applied, it is expected that the device can be applied as an electron source for an image display device.

By the way, the electron source using the surface conduction electron-emitting device has a problem that the emission current gradually decreases when driven for a long time. It is considered that this is because the electric field intensity near the electron emission portion during driving is extremely high, so that a change with time occurs near the electron emission portion and the amount of emitted electrons decreases.

An object of the present invention is to provide a manufacturing apparatus and a manufacturing method of an electron source for reducing the emission current of the electron source with time and suppressing instability.

[0019]

In order to achieve the above object, according to the present invention, the relationship between a current I and a voltage V in a voltage range accompanied by electron emission from an electron-emitting device is determined.

[0020]

(Equation 5) F ′ (V) is expressed by f
When the differential coefficient of (V) is used, after driving in advance with the preliminary driving voltage of V1,

[0021]

(Equation 6) In order to perform normal driving at a voltage V2, the pre-driving voltage V1 is applied to all elements of an electron source in which a plurality of electron-emitting devices are arranged on a substrate in a matrix by row and column wirings. At this time, the voltage Vx is applied to the electron-emitting device from the row-direction wiring of the electron source and the voltage Vx
The power supplied to the electron source is increased at predetermined time intervals in accordance with the application of, and the pre-driving voltage V1 is applied to all elements on the electron source.

[0022]

According to the above arrangement, by performing the preliminary driving, the stability of the electron emission characteristics of the electron emission element constituting the electron source is improved. Also, by gradually increasing the power applied to the electron-emitting device during the pre-driving, the structural members of the device can be changed gradually, and the pre-driving can cause destruction and deterioration of the device and abnormal occurrence of electron emission characteristics. Etc. can be prevented.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. [Example 1] In response to the above-described problem, the applicants
It has been found that a temporal change can be reduced by performing a driving method called preliminary driving prior to normal driving. Here, the preliminary driving will be described.

As described above, when forming the electron emission portion of the surface conduction electron-emitting device, carbon or a carbon compound is deposited near the electron emission portion by the activation process after the energization forming process. . Further, it is preferable to perform a stabilization step after the activation of the current supply. This step is a step of exhausting the organic substance in the vacuum container. It is preferable to use a vacuum-evacuation device that does not use oil so that an organic substance such as oil generated from the device does not affect the characteristics of the element. Specifically, a vacuum evacuation device such as a magnetic levitation type turbo molecular pump, a cryopump, a sorption pump, an ion pump and the like can be mentioned. The partial pressure of the organic component in the vacuum container is preferably 1 × 10 ⁻⁶ Pa or less, more preferably 1 × 10 ⁻⁶ Pa or less, at which the above-mentioned carbon and carbon compounds are hardly newly deposited.
Particularly preferred is 10 ^-8 Pa or less. Further, when evacuating the inside of the vacuum vessel, it is preferable to heat the entire vacuum vessel to facilitate evacuating the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device. A pre-driving process is an energizing process performed prior to normal driving in an atmosphere in which the partial pressure of organic substances is reduced in such a vacuum atmosphere obtained by the stabilization process.

As described above, in the surface conduction electron-emitting device, the electric field intensity near the electron-emitting portion during driving is extremely high.
For this reason, when driven for a long time at the same driving voltage, there is a problem that the amount of emitted electrons gradually decreases. It is considered that a change with time in the vicinity of the electron emitting portion due to the high electric field strength is caused by a decrease in the amount of emitted electrons.

This will be described. According to Fowler and Nordheim et al., The relationship between the current I emitted from the FE type electron-emitting device and the voltage V applied between the cathode and the gate is:

[0027]

(Equation 7) It is represented by In the above formula, A and B are constants depending on the material and the emission area near the electron emission portion, β is a parameter depending on the shape near the electron emission portion, and the voltage V
Multiplied by β is the electric field strength. Here, the FE type electron-emitting device will be described as an example. In the case of a surface conduction type electron-emitting device, the same equation is applied to a device current or an emission current I with respect to a voltage V applied between a pair of electrodes. This is because they have been found to be expressed in the same way simply by replacing.

When the electrical characteristics plotted in the graph of FIG. 6 are approximated by a straight line (broken line in FIG. 6), the value obtained by dividing the applied voltage V by the slope S of the approximate straight line has a minus sign.

[0029]

(Equation 8) Is proportional to the intensity of the electric field formed between the cathode 23 and the gate 24.

Further, if the above relationship is expressed more generally, the relationship between the emission current I and the voltage V can be expressed as

[0031]

(Equation 9) F ′ (V) is expressed by f
When the differential coefficient of (V) is obtained, the electric field strength at voltage V is given by (Equation 3).

[0032]

(Equation 10) Is expressed as

[0033]

[Equation 11] It turns out that it is proportional to.

A typical value of the electric field intensity in the FE type electron-emitting device is a very high value on the order of about 10 ⁷ V / cm. This point is also applied between the pair of electrodes of the surface conduction electron-emitting device.

When driving is continued for a long period of time by the usual method under such a large electric field strength, a change in the components under a strong electric field occurs irregularly, and the emission current value becomes unstable. Become. In addition, when the above-mentioned change occurs irreversibly, the emission current is often reduced, and appears as a decrease in luminance in the image display device. The above-described instability of the current during driving can be reduced by performing preliminary driving, which is a driving method performed prior to normal driving.

The preliminary driving according to the present invention is performed, for example, in the following procedure. First, the applied voltage and emission current of at least two different drive voltages of the electron-emitting device to which the preliminary driving is applied, and the derivative of the emission current at each applied voltage are determined. For example, as shown in FIG. 7, the emission current value I1 corresponding to the applied voltage of V1 and V1
The amount of change dI in the emission current when the value is slightly changed by dV1
From 1, the derivative I′1 of the emission current is calculated as I′1 = dI1 / d
V1 and similarly, the emission current value I2 corresponding to V2
And the differential coefficient I′2.

Next, f (V) in (Equation 7) corresponding to each applied voltage V1 and V2 is defined as I1 and I2, and f '(V) is defined as I'1 and I'2 (Equation 7). Compare the values obtained from At this time, for example,

[0038]

(Equation 12) Is obtained, V1 is adopted as a preliminary drive voltage (hereinafter, referred to as Vpre), and V2 is adopted as a normal drive voltage (hereinafter, referred to as Vdr).
vice versa,

[0039]

(Equation 13) Is obtained, V2 is adopted as a preliminary drive voltage (hereinafter, referred to as Vpre), and V1 is adopted as a normal drive voltage (hereinafter, referred to as Vdr).

It is desirable that the pre-driving be performed for a time until the electric field intensity during driving is stabilized. However, if the pre-driving is continued until the relative change rate of the electric field intensity during pre-driving falls within 5%. Further, it was found that the fluctuation rate of the electric field intensity was within about 5% even if the driving was continued, and the effect of the preliminary driving was sufficiently realized. Therefore, from (Equation 7), f (V1) / {V · f ′ (V1) −2f (V1)}
The preliminary driving may be performed until the rate of change of the value becomes within 5%.

At the time of the preliminary driving, it is preferable to apply a voltage while monitoring the rate of change of the electric field intensity during the preliminary driving. A pulse voltage can be preferably used as the pre-driving voltage. For example, the change rate of the electric field intensity is calculated during the pulse pause time (between the application of the pulse voltage and the application of the next pulse voltage). The application of the voltage may be performed, and the application of the voltage may be stopped when the rate of change becomes within 5%.

The following method can be used to check the rate of change of the electric field intensity during the preliminary driving. During the pre-driving, the pre-driving voltages V1 and V1 and the voltage V12 different from the very small voltage dV1 are continuously applied, and the currents I1, I12, and I1, I12 flowing when the respective voltages are applied.
Is obtained. Here, f ′ (V1) = dI1 /
Since dV1 and f (V1) = I1 from (Equation 5), the above-mentioned f (V1) / ｛V · f ′ (V1) −2f
(V1)｝

[0043]

[Equation 14] It follows that the rate of change of the value of Epre can be seen.

FIG. 8 shows a voltage waveform in the preliminary driving.
Voltage waveforms as shown in (a), (b) and (c) can be used. FIG. 8A is a voltage waveform in which the voltage changes over the T12 time to the voltage V12 immediately after the pre-driving voltage V1 is applied for the T1 time. FIG. 8B shows a voltage waveform in which the voltage V12 is applied for T12 immediately after the preliminary drive voltage V1 is applied for T1. FIG. 8C shows that the voltage of V12 is changed to T1 after the pre-driving voltage V1 is applied for T1 time.
It is a voltage waveform applied for 12 hours. Each applied voltage V1, V
The change rate of the value of Epre is determined from the current value at 12, and the preliminary driving may be performed until the change rate is within 5%.

Further, in the electron-emitting device corresponding to (Equation 8) subjected to the stabilization step, the device current If and the emission current Ie have MI characteristics with respect to the device voltage Vf, and have the MI characteristics with respect to the device voltage Vf. The element current If and the emission current Ie are uniquely determined. At this time, the If-Vf characteristics and the Ie-Vf characteristics depend on the maximum voltage Vmax applied after the stabilization step.

Regarding the IV characteristics of this electron-emitting device,
This will be described with reference to FIGS. FIG.
FIG. 9B is a diagram illustrating a relationship between f and Vf, and FIG. 9B is a diagram illustrating a relationship between Ie and Vf.

In FIGS. 9A and 9B, the solid line shows the IV characteristics of the element driven at the maximum voltage Vmax = Vmax1. When this element is driven at an element voltage lower than Vmaxl, I-
It has the same IV characteristic as the V characteristic. However, Vmaxl
When the device is driven at the above voltage Vmax2, the device exhibits different IV characteristics as shown by a broken line in the figure. When this device is driven at a device voltage of Vmax2 or less,
It has the same IV characteristic as the IV characteristic shown by the broken line. This is probably because the maximum voltage Vmax applied to the electron-emitting device changes the shape of the electron-emitting portion, the electron-emitting area, and the like.

By pre-driving the element with the element voltage V1 in the pre-driving step, as shown in FIG. 10, the electron-emitting element has the lf-Vf characteristic and Ie-Vf uniquely determined by the voltage Vmax = V1. It has characteristics.

Next, the element current at the element voltage Vf1 at the end of the pre-driving is defined as If1, and from the If-Vf characteristic determined by the pre-driving, the voltage V satisfies If2 ≦ 0.7Ifl.
f2 is selected as the drive voltage (Vf2 in FIG. 10). This is because a decrease in emission current can be suppressed for a long time by setting the drive voltage to satisfy If2 ≦ 0.7If1.

Even if the drive voltage Vf2 that satisfies If2 ≦ 0.7 Ifl is applied to the element that has been pre-driven at the element voltage Vf1 as described above, the shape of the electron emission portion and the emission area hardly change. Therefore, during driving, the device is driven with a lower device current If than during pre-driving, while having substantially the same emission area as during pre-driving. Therefore, it is considered that the current density of the device current flowing to the electron-emitting portion during driving can be reduced, the thermal deterioration of the electron-emitting portion can be suppressed, and electrons can be stably emitted for a long time.

In the pre-driving, when driving at a voltage lower than the pre-driving voltage after the pre-driving, the If
It may be performed for a time necessary for the -Vf characteristic and the Ie-Vf characteristic not to change, and the pulse width may be several μsec to several tens ms.
ec, preferably by applying a pulse voltage of 10 μsec to 10 msec several pulses to several tens of pulses or more,
It can be carried out.

In the case where V1> V2, there is a relation such as (Equation 9), the preliminary driving voltage Vpre
, The normal drive voltage Vdr becomes higher and Vp
A higher electric field intensity is applied to the electron emitting portion (referred to as an electron emitting portion A) changed by the voltage of re when the voltage of Vdr is applied. However, the main electron emission source that determines the electron emission amount at this time is another different electron emission portion (referred to as an electron emission portion B), and the contribution of the electron emission portion A to the total emission current is small. Even in such a relationship, the pre-driving is still effective, and by applying the voltage of Vpre in advance, a significant fluctuation factor of the electron emission portion A is reduced in advance, and the destruction at the subsequent driving voltage of Vdr is destructive. Can be prevented beforehand.

The pre-driving method described above is based on the F
It is also effective for electron-emitting devices other than the E-type electron-emitting device and the surface conduction electron-emitting device, for example, MIM-type electron-emitting devices.

Even when manufacturing an electron source having a plurality of electron-emitting devices, such as a multi-electron source in which a large number of electron-emitting devices are arranged in a simple matrix, all the elements constituting the electron source must be By performing the preliminary driving process, a multi-electron source having stable electron emission characteristics can be realized.

In the present embodiment, an example is shown in which the pre-driving of the present invention is applied to a multi-electron source in which a plurality of surface conduction electron-emitting devices are arranged in a matrix by column wiring and row wiring. First, a preliminary driving device according to the present embodiment will be described with reference to FIG. In the figure, reference numeral 101 denotes an electron source for performing preliminary driving. It is assumed that the forming process, the activation process, and the stabilization process of the electron source 101 have already been completed. The electron source 101 is connected to a vacuum exhaust device (not shown).
It is evacuated to about ^10-7 Pa or less. Further, the row direction wiring is terminals Dx1 to Dxm, and the column direction wiring is terminals Dy1 to Dx1 to Dx1.
Each is connected to Dyn.

Reference numeral 102 denotes a row-direction wiring selection circuit for selecting a row-direction wiring for pre-driving, and includes m switching elements therein. Each switching element is connected to the output of the row direction pulse generator 103 or 0 [V] (ground level).
Is selected, and the terminals Dx1 to Dx1 of the electron source 101 are selected.
It can be electrically connected to xm. Switching of each switching element is performed by a control device 104 such as a CPU.

The row direction pulse generator 103 is connected to the control device 10
By the control from 4, it is possible to generate a pulse having a predetermined peak value, pulse width, and period for each pulse.

Reference numeral 105 denotes an ammeter which samples an output current from the row-direction wiring side pulse generator 103 at a predetermined timing and outputs the value to the control device 104 as a digital value.

Column direction pulse generators Py1 to Pyn106 are connected to the respective column direction wirings via terminals Dy1 to Dyn. The column direction pulse generators Py1 to Pyn106 are the control device 1
A pulse having predetermined peak values Vc1 to Vcn and having the same pulse width, cycle and phase as the pulse output from the row direction pulse generator 103 can be generated by the control from step 04.

Next, the pre-driving method of this embodiment will be described. In the preliminary driving of the present invention, the power applied to the electron source, that is, the surface conduction type emission element is gradually increased at predetermined time intervals, and the surface conduction type emission element is finally changed while the structural members of the element are gradually changed. It is characterized in that a pre-driving voltage Vpre capable of generating an electric field intensity sufficient to stabilize the element is applied.

Therefore, in this embodiment, a rectangular pulse having a period of 10 ms is applied to the surface conduction electron-emitting device with a pulse width P
The w (t) and the peak value Vp (t) were applied while increasing at predetermined intervals. Specifically, Vp (t) = 0
[V], Pw (t) = 0 [ms] to Vp (t) = Vp
re [V], 1 [sec] until Pw (t) = 1 [ms]
Each time, Vp (t) is 0.16 [V] and Pw (t) is 0.1
The voltage was applied to the surface conduction electron-emitting device for 100 [sec] while increasing by [ms]. Then, Vp (t) = Vpre
[V], 60 while maintaining Pw (t) = 1 [ms].
[Sec] was applied to the surface conduction type emission device.

The value of the voltage Vpre in this embodiment is 1
6.0 [V]. This makes the drive voltage Vdr 14.5.
Since [V] was set, the electric field intensity was V
It is selected as a value that is larger than when dr is applied. When the configuration of the surface conduction electron-emitting device used for the electron source, the driving voltage Vdr, and the like are changed, Vpre, pulse period, pulse width, pulse waveform, pulse application time, pulse width and peak value increase rate, It is necessary to reset etc. to appropriate values.

In the present embodiment, both the pulse width and the wave height are increased at predetermined time intervals in order to gradually increase the power applied to the surface conduction electron-emitting device at predetermined time intervals. If possible, a method of increasing only the pulse width every predetermined time or a method of increasing only the peak value every predetermined time may be adopted.

In this embodiment, the preliminary driving as described above is performed by
This is performed in units of one row wiring. As soon as the pre-driving for one row is completed, the pre-driving is performed for all the surface conduction electron-emitting devices of the electron source by sequentially switching the row-direction wirings for pre-driving.

In the following, a case where the surface conduction electron-emitting device group on the first row is preliminarily driven will be described as an example. In FIG. 2, F1 to Fn are surface conduction type emission devices on the row direction wiring,
r1 to rn are wiring resistances of each section in the row direction wiring, R
y is the wiring resistance from the terminals Dy1 to Dyn to the surface conduction electron-emitting device in the column direction wiring. Since the row-directional wiring is designed to be formed of a fixed line width, thickness, and material, r1 to rn may be considered to be equal except for manufacturing variations. In addition, since each column direction wiring is usually designed to be equal, each Ry may be considered to be equal. Note that the equivalent resistance of each element is much larger than the value of Ry, and the effect of Ry can be almost ignored. The equivalent resistance value of the surface conduction electron-emitting device is designed to be larger than that of r1 to rn.

In order to pre-drive the surface conduction electron-emitting device group in the first row, the control device 104
2 and outputs the output of the row direction pulse generator 103 to the terminal D.
Connect to x1. Further, the control device 104 sequentially outputs the output of the row direction pulse generator 103 (in this embodiment, every 1 [sec]).
After adjustment, a rectangular pulse having a period of 10 [ms], a pulse width Pw (t) and a peak value Vp (t) is output.

When the preliminary driving is performed, a voltage drop occurs on the row direction wiring due to the wiring resistances r1 to rn and the current flowing through the row direction wiring.
The voltage applied to y1 to Gyn has a voltage distribution. Therefore, in order to cancel this voltage distribution, the control device 104 calculates the voltage distribution generated in the row direction wiring, and further sets the output peak values Vc1 to Vcn of the column direction pulse generators Py1 to Pyn106 to be the same as the above voltage distribution. Adjust as follows. The column direction pulse generators Py1 to Pyn106 have the same cycle, pulse width, and phase as the pulse output from the pulse generator 103, and have a peak value of V
The pulses c1 to Vcn are output to terminals Dy1 to Dyn. By doing so, the voltage applied between the terminals of the elements F1 to Fn can be made substantially constant. In the present embodiment, the peak value of the pulse output from the row direction pulse generator 103 is changed every predetermined time. That is, the current flowing through the row direction wiring increases and the voltage distribution changes, but one pulse is generated. By adjusting the peak values Vc1 to Vcn every time the voltage is applied, that is, every 10 [ms], the voltage applied between the terminals of the elements F1 to Fn can always be kept substantially constant.

In this embodiment, the control unit 104 calculates the voltage distribution as follows. Assuming that during pre-driving, approximately equal currents flow through all elements,
Then, based on the pre-driving current I detected by the ammeter 105, the element current values i1 to in flowing through the elements F1 to Fn are calculated.

[0069]

(Equation 15) Can be estimated as

At this time, the voltages Vc1 to Vcn to be output by the pulse generators Py1 to Pyn106 correspond to the wiring resistance values r1 to rn ≒.
Using r

[0071]

(Equation 16) Is calculated as

FIG. 3 shows an example in which a voltage distribution applied to both ends of the elements F1 to Fn at the time of pre-driving is calculated by the above calculation. The horizontal axis indicates element numbers F1 to Fn, and indicates the position of the element. The vertical axis indicates the terminal voltage at both ends of the element. In this example, a voltage having a peak value of 16 [V] is applied to the terminal Dx1 from the row direction pulse generator 103.

In this embodiment, the voltage distribution is calculated by measuring the pre-driving current I with the ammeter 105. However, the current is not actually measured, and the voltage of the surface conduction type emission device is not measured. It is also possible to estimate the pre-driving voltage from the current characteristics and calculate the voltage distribution.

In the above description, the pre-driving of the elements on the row-directional wiring of the first row has been described. However, the same applies to the pre-driving of the elements on other row-directional wirings.

Now, an appropriate element is selected from the surface conduction electron-emitting element substrate 101 to which Vpre = 16 [V] is applied, and calculated by using the electric field strength of the element by the above (Equation 3) and (Equation 6). , Β was estimated to be 4.5 × 10 ⁶ [1 / cm]. Electric field strength when 16 V is applied F = β × Vpre
Was 7.2 × 10 ⁷ [V / cm].

Then, the Vdrv voltage is set to 1
Driving was performed at 4.5V. When β at 14.5 V was measured, β was 4.5 × 10 ⁶ [1 / cm], and F =
It was estimated to be 6.5 × 10 ⁷ [V / cm].

Another surface conduction electron-emitting device substrate was prepared, and driving was performed by setting the driving voltage to 14.5 V from the beginning without performing preliminary driving, and the two were compared. Then, the surface conduction electron-emitting device substrate that has been preliminarily driven has a stable electron emission characteristic with less decrease and fluctuation of the device current and the emission current during driving than the surface conduction electron-emitting device substrate that has not been preliminarily driven. Obtained.

[Embodiment 2] In this embodiment as well, pre-driving was performed for one row in the row direction wiring for an electron source having the same configuration as that in Embodiment 1. The difference between the electron source used in the present embodiment and that used in the first embodiment is that
A book and a few things. That is, the number of surface conduction electron-emitting devices per row direction wiring is very small as compared with the electron source used in the first embodiment. In such an electron source, the voltage distribution generated on the row-direction wiring during pre-driving is so small as to be negligible. Therefore, the pulse generator for the column wiring used in the first embodiment to cancel the voltage distribution of the row wiring is unnecessary in the present embodiment.

First, a preliminary driving device according to the present embodiment will be described with reference to FIG. In the figure, reference numeral 401 denotes an electron source for performing preliminary driving. It is assumed that the forming process, the activation process, and the stabilization process of the electron source 401 have already been completed. The electron source 401 is connected to a vacuum exhaust device (not shown),
It is evacuated to about 1 × 10 ⁻⁷ “Pa” or less. Further, the row direction wiring includes terminals Dx1 to Dxm and the column direction wiring (10
) Are connected to terminals Dy1 to Dy10, respectively.

Reference numeral 402 denotes a row-direction wiring selection circuit for selecting a row-direction wiring for pre-driving, and includes m switching elements therein. Each switching element has a pulse generator 4
Either the output 03 or 0 [V] (ground level) can be selected and electrically connected to the terminals Dx1 to Dxm of the electron source 401. The switching of each switching element is performed by a control device 404 such as a CPU.

The pulse generator 403 controls a predetermined peak value, pulse width,
A pulse having a period can be generated. Each column wiring was connected to an electrical ground via terminals Dy1 to Dy10.

Next, the pre-driving method of this embodiment will be described. Also in this embodiment, the power applied to the electron source, that is, the surface conduction electron-emitting device is gradually increased at predetermined time intervals, and while the structural members of the device are gradually changed, the surface conduction electron-emitting device is finally formed. Pre-driving voltage V that can produce an electric field strength sufficient to stabilize
Apply pre.

Therefore, also in this embodiment, a rectangular pulse having a period of 10 [ms] is applied to the surface conduction electron-emitting device while the pulse width Pw (t) and the peak value Vp (t) are increased at predetermined time intervals. did. Specifically, as in the first embodiment, from Vp (t) = 0 [V] and Pw (t) = 0 [ms], Vp (t) = Vpre [V] and Pw (t) = 1 [m]
s] to Vp (t) 0.16 every 1 [sec]
“V”, 1 while increasing Pw (t) by 0.1 [ms]
The voltage was applied to the surface conduction electron-emitting device for 00 [sec]. Then, Vp (t) = Vpre [V], Pw (t) = 1 [m
s] was applied to the surface conduction electron-emitting device for 60 [sec]. Note that also in this embodiment, the voltage Vpre
Was 16.0 [V].

For example, in order to pre-drive the surface conduction electron-emitting device group in the first row, the control device 404 controls the row direction wiring selection circuit 402 and connects the output of the pulse generator 403 to the terminal Dx1. Further, the control device 404 includes the pulse generator 4
The output of No. 03 is sequentially adjusted (every 1 [sec] in this embodiment), and a rectangular pulse having a period of 10 [ms], a pulse width Pw (t) and a peak value Vp (t) is output.

As described above, as soon as the pre-driving for one row is completed, the pre-driving is performed for all the surface conduction electron-emitting devices of the electron source by sequentially switching the row-direction wiring for pre-driving.

It should be noted that the electron source that has been preliminarily driven in this embodiment has a stable electron emission characteristic with less reduction and fluctuation in the element current and the emission current during driving than the electron source that has not been preliminarily driven. Was done.

[0087]

As described above, according to the present invention, the stability of the electron emission characteristics of the electron-emitting devices constituting the electron source is improved by performing the preliminary driving. Also, by gradually increasing the power applied to the electron-emitting device during the pre-driving, the structural members of the device can be changed gradually, and the pre-driving can cause destruction and deterioration of the device and abnormal occurrence of electron emission characteristics. Could be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a preliminary driving device according to an embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram of an electron source driven by the device of FIG.

FIG. 3 is a diagram showing a voltage distribution in an electron source driven by the device of FIG.

FIG. 4 is a diagram showing a configuration of a preliminary driving device according to another embodiment of the present invention.

FIG. 5 is a graph showing an example of electric characteristics of an electron-emitting device to which the present invention can be applied.

FIG. 6 is an electrical characteristic diagram obtained by changing a scale of FIG. 5;

FIG. 7 is a diagram illustrating voltage waveforms used for pre-driving according to an embodiment of the present invention.

FIG. 8 is a graph showing an example of the relationship between the emission current Ie, the device current If, and the device voltage Vf for the electron-emitting device according to the example of the present invention.

FIG. 9 is a graph showing an example of the relationship between the emission current Ie, the device current If, and the device voltage Vf for the electron-emitting device according to the example of the present invention.

FIG. 10 is a schematic plan view of a surface conduction electron-emitting device.

FIG. 11 is a schematic view of an electron source having a simple matrix arrangement.

[Explanation of symbols]

101, 401: electron source, 102, 402: row direction wiring selection circuit, 103, 403: row direction pulse generator, 10
4,404: control device, 105: ammeter, 106: column direction pulse generator.

Claims (19)

[Claims] 1. The relationship between a current I and a voltage V in a voltage range involving electron emission from an electron-emitting device is given by F ′ (V) is expressed by f
When the differential coefficient of (V) is obtained, after driving in advance with the preliminary driving voltage of V1, the following equation is obtained. In order to perform normal driving at a voltage V2, the pre-driving voltage V1 is applied to all elements of an electron source in which a plurality of electron-emitting devices are arranged on a substrate in a matrix by row and column wirings. An electron source manufacturing apparatus for applying a voltage Vx from a row wiring of the electron source to the electron-emitting device for at least a predetermined time. An electron source manufacturing apparatus characterized by applying a pre-driving voltage V1 to all elements on the electron source every time, and applying a pre-driving voltage V1 to all elements on the electron source. 2. The electron source manufacturing apparatus according to claim 1, wherein the increase in power is realized by increasing the value of the voltage Vx from a value lower than the pre-driving voltage V1 to the pre-driving voltage V1. 3. The apparatus according to claim 1, wherein the voltage Vx is a pulse voltage having a predetermined peak value, a predetermined pulse width, and a predetermined cycle. 4. The electron source manufacturing apparatus according to claim 3, wherein the increase in power is realized by increasing at least a value obtained by dividing a pulse width of the pulse voltage by a period. 5. A row voltage source for applying a voltage Vr to a row wiring of the electron source, a column voltage source for applying a voltage Vc to a column wiring, and an intersection of the row wiring and the column wiring. 5. The electron source manufacturing apparatus according to claim 1, further comprising control means for controlling the voltages Vr and Vc so that the voltage Vx applied to the electron-emitting device becomes a predetermined value. 6. The electron source manufacturing apparatus according to claim 5, wherein the electron source manufacturing apparatus includes an ammeter for measuring a current supplied to the electron source. 7. The apparatus according to claim 6, wherein the control circuit controls the voltages Vr and Vc according to a current value measured by the ammeter. 8. The voltage V1 is If2, a current flowing through the electron-emitting device when the voltage V2 is applied to drive the electron-emitting device after the voltage application process, and the electron emission in the voltage application process. The voltage V1 is applied to the element.
Is applied to the electron-emitting device when Ifl is applied.
The electron source manufacturing apparatus according to claim 1, wherein the voltage is set to If2 ≦ 0.7If1. 9. The driving at the voltage V1 is performed according to the equation (2).
The electron source manufacturing apparatus according to any one of claims 1 to 10, wherein the process is performed until the rate of change of the value on the left side in (5) becomes 5% or less. 10. A relationship between a current I and a voltage V in a voltage range accompanied by electron emission from an electron-emitting device is expressed by the following equation. F ′ (V) is expressed by f
When the differential coefficient of (V) is obtained, after driving with the preliminary driving voltage of V1 in advance, In order to perform normal driving at a voltage V2, the pre-driving voltage V1 is applied to all elements of an electron source in which a plurality of electron-emitting devices are arranged on a substrate in a matrix by row and column wirings. An electron source manufacturing method for
A voltage application step of applying a voltage Vx to the electron-emitting device from at least a row-direction wiring of the electron source; increasing a power supplied to the electron source with the application of the voltage Vx every predetermined time; A method for manufacturing an electron source, comprising applying a preliminary drive voltage V1 to an element. 11. The method according to claim 10, wherein the increase in the power is realized by increasing the value of the voltage Vx from a value smaller than the preliminary driving voltage V1 to the preliminary driving voltage V1.
The method for producing an electron source according to the above. 12. The method according to claim 10, wherein the voltage Vx is a pulse voltage having a predetermined peak value, a predetermined pulse width, and a predetermined period. 13. The method according to claim 12, wherein the increase in the power is realized by increasing at least a value obtained by dividing a pulse width of the pulse voltage by a period. 14. A row direction potential applying step of applying a potential Vr to a row direction wiring of said electron source, and a potential Vc to a column direction wiring.
And a voltage V applied to the electron-emitting device at the intersection of the row direction wiring and the column direction wiring.
14. The method according to claim 10, further comprising a control step of controlling the potentials Vr and Vc so that x becomes a predetermined value. 15. The method for manufacturing an electron source according to claim 14, wherein the apparatus for manufacturing an electron source includes a current measuring step of measuring a current supplied to the electron source. 16. The method according to claim 15, wherein the control step controls the potentials Vr and Vc according to a current value measured in the current measurement step. 17. The voltage V1 is If2, a current flowing through the electron-emitting device when the voltage V2 is applied to drive the electron-emitting device after the voltage-applying step. The voltage V is applied to the element.
1 is applied, and the current flowing through the electron-emitting device is If.
17. The method for manufacturing an electron source according to claim 10, wherein a voltage that satisfies If2 ≦ 0.7If1 when l is set. 18. The method according to claim 10, wherein the driving at the voltage V1 is performed for a period of time until the rate of change of the value on the left side in the equation (2) becomes 5% or less. Electron source manufacturing method. 19. An electron source comprising a plurality of electron-emitting devices arranged on the substrate, wherein the electron source manufacturing apparatus according to claim 1 or the electron source manufacturing apparatus according to claim 10. An electron source manufactured by using the method for manufacturing an electron source according to (1).