JP2001324957A - Electron source and method for driving picture display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron source equipped with plural electron discharge elements having a uniform electron discharge characteristics, and to provide a method for driving a picture display device having a small power supply capacity using the electron source and little variation in brightness. SOLUTION: This picture display device has a substrate 101 provided thereon with plural row wiring Dx1-Dxm, plural column wiring Dy1-Dyn, and plural electron discharge elements, and comprises a line side current detecting part 110 and a picture selection side current detecting part 107, a line selecting part 102 for selecting arbitrary row wiring from the plural row wiring Dx1-Dxm and having a 1st voltage impression process for applying a voltage to the plural column wiring Dy1-Dyn for compensating for a voltage drop influenced by the selected row wiring, and a picture selection side output voltage amplifier 111 including a pixel side selecting part 11a having a 2nd voltage impression process for applying a prescribed voltage to at least a specific electron discharge element among the plural electron discharge elements connected with the row wiring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron source in which a plurality of electron-emitting devices are arranged, and a method for driving an image display device using the same.

[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, 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. ing.

Examples of the FE type include, for example, WPDyke &
WWDolan, "Field emission", Advance in Electron Ph
ysics, 8, 89 (1956) or CASpindt, "Physical
properties of thin-film field emission cathodes w
ith molybdenium cones ", J. Appl. Phys., 47, 5248 (197
6) are known. Examples of the MIM type include, for example, CAMead, "Operation of tunnel-emission device"
es ", J. Appl. Phys., 32, 646 (1961) and the like.

[0004] As the surface conduction type emission element, for example, M.
I. Elinson, Radio E-ng. Electron Phys., 10, 1290, (19
65) and other examples described below. The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. As this surface conduction type emission element,
In addition to those using a SnO ₂ thin film by Elinson et al., Those using an Au thin film [G. Dittmer: “Thin Soli”
d Films ", 9, 317 ( 1972)] and, In ₂ O ₃ / SnO ₂ by thin film [M.Hartwell and CGFonstad:" IEEETrans.
ED Conf. ", 519 (1975)] and those using carbon thin films [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, 22 (198)
3)] has been reported.

[0005] As a typical example of the device configuration of these surface conduction electron-emitting devices, FIG. 14 is a plan view of the device by M. Hartwell et al. Described above. In the figure, reference numeral 3001 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 applying an energization process called energization forming to be described later to the conductive thin film 3004. The interval L in the figure is 0.5 to 1 [mm], and the width W is
It 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 shape, and the position and shape of the actual electron-emitting portion are faithfully represented. Not necessarily.

In the above-described surface conduction electron-emitting device including the device by M. Hartwell et al., An electron-emitting portion 3005 is formed by applying an energization process called energization forming to the conductive thin film 3004 before electron emission. Was common. That is, the energization forming means that a constant DC voltage is applied to both ends of the conductive thin film 3004, or
For example, a DC voltage which is boosted at a very slow rate of about 1 [V / min] is applied to energize the conductive thin film 30.
04 locally destroyed or deformed or altered,
This is to form the electron-emitting portion 3005 in a state of being electrically high in resistance. Note that a crack is generated in a part of the conductive thin film 3004 that is locally broken, deformed, or altered. When an appropriate voltage is applied to the conductive thin film 3004 after the energization forming, electrons are emitted in the vicinity of the crack.

The above-mentioned surface conduction electron-emitting device has an advantage that a large number of devices can be formed over a large area because of its simple structure and easy manufacture. Therefore, as disclosed in, for example, Japanese Patent Application Laid-Open No. 64-31332 by the present applicant, a method for arranging and driving a large number of elements has been studied. As for the application of the surface conduction electron-emitting device, for example, image forming devices such as image display devices and image recording devices, and charged beam sources have been studied.

Particularly, as an application to an image display device, for example, as disclosed in US Pat. No. 5,066,883 and Japanese Patent Application Laid-Open No. 2-257551 by the present applicant, a surface conduction electron-emitting device and electron irradiation are disclosed. An image display device using a combination of a phosphor (fluorescent film) that emits light according to the technology has been studied. An image display device using a combination of the surface conduction electron-emitting device and a phosphor is expected to have better characteristics than other conventional image display devices.
For example, in comparison with liquid crystal display devices that have become widespread in recent years,
Since it is a self-luminous type, it can be said that a point that does not require a backlight and a point that a viewing angle is wide are excellent.

The inventors of the present application have attempted surface conduction type emission devices having various materials, manufacturing methods and structures, including those described in the above-mentioned conventional examples. Furthermore, research has been conducted on a multi-electron source in which a large number of surface conduction electron-emitting devices are arranged, and on an image display device using the multi-electron source.

Further, the present inventors have tried a multi-electron source by an electric wiring method shown in FIG. 15, for example.
That is, a large number of surface conduction emission devices are two-dimensionally arranged,
A multi-electron source in which these elements are wired in a matrix as shown.

In the figure, 4001 schematically shows a surface conduction electron-emitting device, 4002 shows row wirings, and 4003 shows column wirings. These row wiring 4002 and column wiring 4003
Actually have a finite electrical resistance, but are shown as wiring resistances 4004 and 4005 in the figure. The above-described wiring method is called simple matrix wiring. Note that, for convenience of illustration, the matrix is shown as a 6 × 6 matrix, but the size of the matrix is not limited to this. For example, in the case of a multi-electron source for an image display device, a desired image is displayed. In this case, only enough elements are arranged and wired.

In the multi-electron source in which the surface conduction electron-emitting devices are arranged in a simple matrix as described above, in order to output a desired electron beam, the row interconnection 4002 and the column interconnection 4
003, an appropriate electric signal is applied. 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 wiring 4002 of a selected row, and a non-selected state is applied to a row wiring 4002 of an unselected row. A selection voltage Vns is applied. In synchronization with this, a drive voltage Ve for emitting electrons is applied to the column wiring 4003. According to this method, if the voltage drop due to the wiring resistances 4004 and 4005 is ignored, a voltage of (Ve−Vs) is applied to the surface conduction type emission element of the selected row, and the surface conduction type emission element of the non-selected row is selected. A voltage of (Ve-Vns) is applied to the emission element. Here, if these Ve, Vs, and Vns are set to appropriate voltage values, electrons of a desired intensity should be output only from the surface conduction electron-emitting devices in the selected row.
If a different drive voltage Ve is applied to each of the column wirings 4003, electrons of different intensities should be output from each of the elements in the selected row. In addition, the surface conduction type emission element 4
Since the response speed of 001 is high, if the length of time for applying the drive voltage Ve is changed, the length of time for outputting the electron beam should be able to be changed.

Therefore, various applications are considered for a multi-electron source in which the surface conduction electron-emitting devices are arranged in a simple matrix wiring. For example, if a voltage signal corresponding to image information is appropriately applied, an electron source for an image display device can be obtained. It is expected that it can be applied as

On the other hand, the inventors of the present application have conducted intensive studies for improving the characteristics of the surface conduction electron-emitting device, and as a result, have found that it is effective to carry out the activation process in the manufacturing process.

As described above, when forming an electron-emitting portion of a surface conduction electron-emitting device, a current is applied to a conductive thin film to locally break, deform, or alter the thin film, thereby forming a crack. Processing (energization forming processing) is performed. Thereafter, by further performing the activation process, the electron emission characteristics can be significantly improved.

That is, the energization activation process is a process of energizing the electron-emitting portion formed by the energization forming process under appropriate conditions to deposit carbon or a carbon compound (an activating substance source) in the vicinity thereof. That is. By applying a voltage pulse periodically in a vacuum atmosphere of 10 −5 [torr], one of single-crystal graphite, polycrystalline graphite, and amorphous carbon, or an amorphous carbon in the vicinity of the electron-emitting portion. Mix 500
[Angstrom] Deposited with a film thickness of not more than [angstrom]. However,
This condition is merely an example, and it is needless to say that the condition should be appropriately changed depending on the material and the shape of the surface conduction electron-emitting device. By performing such processing, the emission current at the same applied voltage can typically be increased by 100 times or more as compared to 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. Therefore, it is needless to say that even when manufacturing a multi-electron source in which a large number of the above-described surface conduction electron-emitting devices are wired in a simple matrix, it is desirable to perform the activation process for each device.

Here, FIG. 16 shows a schematic diagram of a measurement system of the device current If and the emission current Ie flowing through the surface conduction electron-emitting device during the activation process. This figure shows a measurement system of the device current If and the emission current Ie during the activation process.

Conductive thin film 1 having electron emitting portion 1113
104 is connected to an activation power supply 1112 via electrodes 1102 and 1103. Reference numeral 1114 denotes an anode electrode for supplementing the emission current Ie emitted from the surface conduction electron-emitting device. A DC high-voltage power supply 1115 and an ammeter 1116 are connected to the anode electrode 1114.

In the activation treatment, an activation power supply 1112 is applied between the device electrodes (electron emission portions 1113) as appropriate under an atmosphere containing an organic substance (hereinafter, this gas atmosphere is referred to as an activation gas pressure). It is shown that the voltage pulse is repeatedly applied. FIG. 17 shows an example of the element current If and the emission current Ie measured by the ammeters 1111 and 1116. Activation power supply 1112
When the pulse voltage starts to be applied from FIG. 16 (FIG. 16), the device current If and the emission current Ie increase with time. When the device current If and the emission current Ie have reached desired values, the voltage application is stopped and the process ends. By ending the activation step with the preset device current value and emission current value in this way, the reproducibility of the device current If and the emission current Ie is improved.

In the following, the device current If and the emission current Ie for monitoring the progress of activation are referred to as the device current If profile and the emission current Ie profile, respectively.
In addition, in the configuration shown in FIG. 16, a phosphor is applied to the lower side of the anode electrode 1114 and driven, so that the phosphor can be used as an image device.

By adding such an energization activation process, the electron emission characteristics of the surface conduction electron-emitting device were stabilized, but this was applied to a multi-surface conduction electron-emitting device such as a simple matrix wiring. In this case, there are the following problems.

For example, when these surface conduction electron-emitting devices are arranged by a simple matrix wiring of m rows and n columns, current is activated at regular intervals in the order of row wirings from row 1 to row m to activate them. Will be. FIG. 18 shows an equivalent circuit when the electron emission / transmission element wired in a simple matrix is activated. FIG. 18 shows a state in which a voltage waveform for activation is applied to the elements connected to the second row wiring.

FIG. 19 is a diagram showing the waveform of the applied voltage signal in this activation process. A voltage waveform having a pulse width T1 and a voltage value Vf0 of a period T2 is applied. Here, the activation time of each row wiring is determined from the activation characteristics of each element as shown in FIG. However, there is a problem in the case where the energization activation is performed on a row-by-row basis for elements arranged in a large-scale matrix.

That is, when the matrix wiring becomes large,
The effect of the voltage drop due to the wiring resistance increases, and there are elements to which a sufficient voltage cannot be applied, and the electron emission element characteristics of each element vary.

In order for each element to have a uniform electron emission characteristic, it is necessary to apply a uniform voltage to each element. However, as the matrix size increases, a large voltage is applied due to the effect of the wiring resistance of the row wiring. Since a drop occurs, a predetermined voltage cannot be applied. In particular, since a desired voltage cannot be applied to the element substantially at the center of the row wiring, an element that cannot be sufficiently activated is formed, and the characteristics of the elements wired in a matrix vary.

FIGS. 20A and 20B are diagrams schematically showing the voltage drop in the matrix wiring. FIG. 20 (a)
Schematically shows the voltage applied to each element when the element in the second row is activated by applying a voltage value Vf0 in the simple matrix wiring of m rows × n columns shown in FIG. . Now, the element in the second row and first column is F (2,1), the element in the second row and second column is F (2,2), and the element in the second row and third column is F (2).
(2, 3), and the horizontal axis in FIG. 20 indicates the column number (pixel number). Here, as shown in FIG. 18, since the voltage is applied from both sides of the row wiring, the voltage drop has the largest effect at the k-th column substantially at the center, and the voltage value applied to the element F (2, k) Is Vfk (<Vf0). In other words, the voltage Vfdk (= Vf0−
Vfk).

The effect of the voltage drop caused by the wiring resistance as described above can be eliminated by changing the voltage applied from the electrode on the column wiring side. This is shown in FIG.
0 (b), this figure shows an example of compensating for this voltage drop by the voltage applied from the electrode on the column wiring side. FIG. 21 shows an example for compensating the effect of the voltage drop from the electrode on the column wiring side. FIG. 4 is a schematic diagram when a voltage is applied. This FIG.
In an element configuration of a simple matrix wiring of m rows × n columns,
This shows a state where only the elements in the second row are activated.

However, when the above method is used, a compensation voltage is continuously applied to elements other than the selected line under a vacuum in which an organic substance is present (hereinafter referred to as an activation atmosphere). Element has a low resistance, and an invalid current flows.

This reactive current will be described in detail with reference to FIG. In the figure, a pulse voltage having a peak value of Vf is applied to the row wiring of the second row, the voltage Vfd1 in the first column, the voltage Vfd2 in the second column, the voltage Vfd3 in the third column, and the like to the column wiring.
, The voltage Vfdn is applied to the n-th column, and the voltage applied to each element in the second row is set to be approximately Vf. The other row wirings are all 0 [V], that is, grounded. Thereby, the elements F (2, 1), F
The activation voltage Vf is applied to (2,2), F (2,3),..., F (2, n), but the elements other than the elements connected to the second row wiring are Is the voltage V in the element in the first column.
fd1, the voltage Vfd2 is continuously applied to the elements in the second column, and the voltage Vfdn is continuously applied to the elements in the nth column. An element to which a voltage is applied other than the element connected to the row wiring selected in this way is defined as a half-selected element. in this way,
It can be seen that when voltage compensation is performed by applying a voltage from the column wiring, the voltage is continuously applied to other than the selected element. Next, a description will be given of how to reduce the resistance of the element caused by the voltage being continuously applied to the element other than the selected element.

First, the typical IV characteristics of the device in this activation atmosphere, that is, the relationship between the voltage Vf applied to the device and the current If will be described. The typical IV characteristics of the surface conduction electron-emitting device, that is, the relationship between the current (If) flowing through the device and the voltage (Vf) applied to the device will be described with reference to FIG.

In a surface conduction type emission device, the current (If) flowing through the device with respect to the voltage (Vf) applied to the device under an atmosphere in which an organic substance having an appropriate partial pressure is present.
) Is not necessarily determined uniquely. The characteristics are roughly classified into two types. Among them, in the first type, the current (If) flowing through the element is the applied voltage (Vf).
Increases once from 0 [V], then the current starts to decrease, and thereafter shows a substantially constant or slightly increasing tendency. On the other hand, in the second type,
The current (If) flowing through the element always shows an increasing tendency as the applied voltage (Vf) is increased from 0 [V].

For convenience of explanation, the first type is referred to as static characteristics, and the second type is referred to as dynamic characteristics. In FIG. 22, a broken line indicates static characteristics obtained at a voltage sweep speed of about 1 [V / min] or less. In other words, in the region (region A) where Vf = 0 to V1 (region A), the device current (If) flowing through the device monotonically increases as the device voltage (Vf) increases, and reaches a maximum at V1. Further, a region where the device voltage Vf = V1 to V2 (region B)
Then, the current (If) flowing through the element is the element voltage (Vf)
A voltage-controlled negative resistance characteristic (hereinafter referred to as VCNR (Voltage Controlled Negative Re
sistance) characteristics. Further, the device voltage Vf =
In the region of V2 to Vd (region C), the current (If) flowing through the element hardly changes with an increase in the voltage (Vf). Note that the voltage value V1 indicates the element voltage value when the element current If shows the maximum value, and V2 is the Vf-axis intercept of the maximum slope tangent among the tangents of the decreasing curve of the element current If. on the other hand,
As the emission current Ie from the element increases, Ve increases as the electron emission threshold.

The solid line 700 in FIG.
/ Sec] or more, the dynamic characteristics obtained at the voltage sweep speed. That is, when the maximum element voltage is swept at Vd (I
f (Vd) curve), the current (If) flowing to the element from around the element voltage Vf = Ve gradually increases, and the element voltage Vf
= Vd, an element current value almost equal to the element current If showing static characteristics is obtained. The solid line 701 shows the case where the sweep is performed at the maximum voltage V2 (refer to the If (V2) curve). The device current If gradually increases in the regions A and B, and almost equals to the static characteristic If at the device voltage V2. A matching element current If is obtained. Further, when the maximum voltage is swept with the maximum voltage in the region A, the static characteristic I shown by the dotted line is obtained.
It shows characteristics that almost match the f-curve. Of course, I
The static characteristics and dynamic characteristics related to -V characteristics change by changing the material constituting the device, the device form, and the like. Generally, a surface conduction electron-emitting device having good electron emission characteristics has the above two characteristics. You can think that it is.

[0034]

As described above,
When the simple matrix driving as described above is performed to activate the individual elements, a voltage is applied to other than the selected desired element. Therefore, as is apparent from FIG. 22, a large amount of reactive current flows due to a voltage applied to elements other than the desired element. Because of such a reactive current,
In addition to the necessity of increasing the size of the activation device, there is also a possibility that heat generation of the display panel is caused, and deterioration of the element is accelerated. Furthermore, depending on the material of the substrate, it is conceivable that the substrate may be broken by thermal stress.

As described above, the problem when the energization activation process is performed on the multi-surface conduction electron-emitting devices wired in a simple matrix has been described. However, the same problem also occurs in the image display process.

For example, when a surface conduction electron-emitting device is connected by a simple matrix wiring of m rows and n columns, 1
Drive is performed by energizing every predetermined time in the order of the row wiring from the row to the m-th row. Also, after driving the m rows, 1
Drive line

FIG. 23 shows an equivalent circuit of the image display step.
A multi-electron beam generator in which m × n electron-emitting devices are connected in simple matrix wiring by m scanning lines and n signal lines is referred to as an image forming apparatus. The anode electrode, the phosphor under the anode electrode, and the DC high-voltage power supply in the drawing are connected. This figure shows a state where the element connected to the second row wiring is being driven.

FIG. 24 is a diagram showing a waveform of an applied voltage signal in this driving. The pulse applied to the second row wiring has a pulse width T1 and a voltage value Vdr of a period T2.
v0, and when the driving of the second row is completed, the third row is driven. In addition, a voltage signal having a signal pulse width T1 or less and -Vdrv0 is applied according to the output voltage in the column side and the image signal. Here, a voltage waveform applied from the first column is shown. As described above, in the image display process, a line-sequential scanning method of forming one screen by sequentially emitting one line of an image is well known.

As described above, even in the image display step of driving in units of rows, when the size of the matrix wiring is large, the effect of the voltage drop due to the wiring resistance increases, and there are elements to which a sufficient voltage cannot be applied. There is a problem that the brightness (electron beam intensity) of each pixel varies.

The present invention has been made in view of the above-mentioned problems in the prior art, and an object of the present invention is to provide an electron source having a plurality of electron-emitting devices having uniform electron-emitting characteristics and to use the same. An object of the present invention is to provide a driving method of an image display device.

Another object of the present invention is to provide a method of driving an image display device having less luminance variation. Another object of the present invention is to reduce the reactive current in driving an electron source having a plurality of electron-emitting devices and an image display device using the same.

Another object of the present invention is to reduce the power supply capacity of a device used in driving an electron source having a plurality of electron-emitting devices and an image display device using the same. Still another object of the present invention is to provide an electron source in which deterioration of an electron-emitting device during driving is prevented and a method of driving an image display device using the same.

[0043]

In order to achieve the above object, a method for driving an electron source according to the present invention comprises a method of forming a plurality of row wirings, a plurality of column wirings, and a plurality of electron-emitting devices on a substrate. Provided, in a method of driving an electron source matrix-wired by the plurality of row wirings and the plurality of column wirings, a current detection step of detecting a current flowing through the plurality of electron-emitting devices,
A first voltage applying step of selecting an arbitrary row wiring from among the plurality of row wirings and applying a voltage to the plurality of column wirings to compensate for the effect of a voltage drop caused by the selected row wirings; And a second voltage applying step of applying a predetermined voltage to at least a specific one of the plurality of electron-emitting devices connected to the row wiring.

In the present invention, in the first voltage applying step, any one of the plurality of row wirings or the plurality of column wirings is selected and the plurality of column wirings or the plurality of column wirings are selected. Applying a voltage to compensate for the effect of a voltage drop caused by the selected row wiring or the column wiring on a plurality of row wirings, wherein the second voltage applying step comprises: It is preferable that a predetermined voltage be applied to at least a specific one of the plurality of electron-emitting devices connected to a wiring. Further, it is preferable that the first voltage applying step is a step of applying a voltage according to a current value detected in the current detecting step.

Preferably, the current detecting step is a step of detecting a current flowing in the row wiring and / or the column wiring when the voltage is applied in the first voltage applying step.

Preferably, the second voltage applying step is a step of increasing the resistance of one or a plurality of the electron-emitting devices.

Further, the method of driving the electron source may include a step of increasing the amount of electrons emitted from the electron-emitting device by driving under an activating substance source. Preferably, the activating substance source is carbon or a carbon compound.

Preferably, in the first voltage applying step, a voltage is applied by sequentially selecting the plurality of row wirings and / or the plurality of column wirings.

Preferably, in the second voltage applying step, a predetermined voltage is applied to all of the plurality of electron-emitting devices connected to the row wiring and / or the column wiring. Further, it is preferable that the second voltage applying step is to apply a predetermined voltage to any one or two or more of the electron-emitting devices.

The method of driving an image display device according to the present invention comprises the steps of: providing a plurality of row wirings, a plurality of column wirings, a plurality of electron-emitting devices, a plurality of the row wirings, and a plurality of the column wirings on a substrate; In a method for driving an image display device including an electron source wired in a matrix and a fluorescent film irradiated with electrons from the electron source, the image display device can be driven by the method for driving the electron source. .

[0051]

Next, preferred embodiments of the present invention will be described in detail with reference to the drawings. [Embodiment 1] In the present embodiment, a reduction in the resistance of non-selected elements occurs when surface conduction electron-emitting devices are wired in a matrix and an image is displayed while compensating for a voltage drop by wiring resistance. And a high-resistance pulse is applied during the flyback period.

FIG. 1 is a block diagram showing an example of an energizing device of the surface conduction electron-emitting device according to the first embodiment.
In FIG. 1, reference numeral 101 denotes a multi-surface conduction electron-emitting device substrate connected for displaying an image (a plurality of surface conduction electron-emitting devices are wired in a matrix on the substrate 101 in the present embodiment. It is assumed that the activation of these elements has already been completed), and the container (not shown) accommodating the substrate 101 has a size of 10 −5 to 10 −7 [torr]. It has been evacuated. A line selection unit 102 selects a row wiring to be driven according to an instruction from the control unit 104,
A voltage is applied from the power supply 103 to the selected row wiring. Reference numeral 110 denotes a line-side current detection unit which detects a current value flowing through each row wiring of the substrate 101 (current detection step).

Reference numeral 107 denotes a pixel selection side current detection unit which detects a value of a current flowing through each column wiring of the substrate 101. The control unit 104 reads the current value detected by the pixel selection side current detection unit 107 (current detection step), and supplies the voltage value obtained by adjusting the voltage drop due to the image display signal and the wiring resistance to the pixel selection side output voltage amplifier 111. At the same time, the selection of the row wiring and the column wiring of the substrate 101 is controlled by controlling the pixel selection section 111a included in the line selection section 102 and the output voltage amplifier 111. Dx1 to Dxm indicate row wiring terminals of the electron source substrate 101, and Dy1 to Dyn indicate column wiring terminals of the electron source substrate 101. The control unit 1
The timer 104a of the timer 04 has a high-resistance holding time T described later.
It is for measuring hr.

Here, the case where the image signal supplied from the outside is an NTSC signal is shown as an example, and the NTSC signal is separated into a vertical synchronizing signal VD, a horizontal synchronizing signal HD and a luminance signal by the synchronizing / separating circuit 121. Is done.

The luminance signal separated by the sync separation circuit 121 is digitized by the A / D converter 122, and when the data of one line of the image is serial / parallel converted by the shift register 123, the line memory Data is written to 124. The line memory 124 outputs the stored data for one line to the pulse width modulator 125. The pulse width modulator 125 generates voltage pulses of different lengths according to the input luminance data.

That is, for example, when an image is displayed in 128 gradations, the time width in units of approximately 1/128 of the scanning time of one line is an integral multiple (n = 0 to 1) according to the luminance level.
27) generates a rectangular voltage pulse. The pulse width of the rectangular voltage pulse is, for example, 60 [nsec] as a reference level, and the ON level of the pulse is 60 [μsec].
In this case, a pulse having an amplitude of 60 [μsec] is used. In the present embodiment, m rows are 240 rows and n columns are 720 columns.

Next, referring to FIG.
The operation in FIG. 1 will be described. FIG. 2 is a circuit diagram showing a circuit configuration of the line selection unit 102. 1 and 2, the line selection unit 102 has a switch such as a relay or an analog switch, and has m rows × n columns of surface conduction electron-emitting devices in a matrix on the surface conduction electron-emitting device substrate 101. When the switches are arranged, m switches such as SWx1 to SWxm are arranged in parallel, and the output of each switch is connected to each of the row wiring terminals Dx1 to Dxm of the electron source substrate 101. These switches are controlled by the control signal 104 from the control unit 104 and operate so that a voltage waveform from the power supply 103 is applied to the row wiring to be driven. In FIG. 2, the first line (Sx
The line 1) is selected, a voltage is applied only to the row wiring terminal Dx1, and the other lines (non-selected row wiring) are connected to the ground.

FIG. 3 shows an output voltage amplifier 111 on the pixel selection side.
FIG. 2 is a circuit diagram showing a circuit configuration of FIG. This voltage amplifier 111 is, as shown in FIG. 1 and FIG.
And the output voltage block. This pixel side selection unit 1
Similarly to the line selection unit 102, the switch 11a includes a relay, an analog switch, etc., and includes n switches SWy1 to SWy.
yn is located. The output of the pixel side selection unit 111a is supplied to the electron source substrate 1 through the pixel selection side current detection unit 107.
01 column wiring terminals Dy1 to Dyn. Also,
Each of the switches SWy1 to SWyn is controlled by a control signal 151 from the control unit 104, and operates so that a voltage from the pixel selection side voltage output amplifier 111 is applied to a line to be driven. FIG.
In, the wiring (Sy2) in the second column is selected,
Other column wirings are connected to the ground.

This pixel selection side output voltage amplifier 111
When an output voltage amplifier is provided and m rows × n columns of surface conduction type elements are arranged in a matrix on the substrate 101, n
The voltage amplifiers 152 are arranged. The outputs AMPy1 to AMPyn of these voltage amplifiers 152 are supplied to the electron source substrate 101 through the pixel-side selection unit 111a and the current detection unit 107.
Are input to the column direction terminals Dy1 to Dyn. The voltage application pattern applied to these column wirings is set by an image signal voltage determined by image signal information and a voltage drop amount by a row wiring that changes according to the image signal. It is input to the selection side output voltage amplifier 111.

FIG. 4 shows a line-side current detector 110 (FIG. 1) and a pixel-selection-side current detector 107 of this embodiment.
FIG. 2 is a block diagram showing the configuration of FIG. FIG.
(A) is a circuit diagram showing a configuration of a line-side current detection unit 110 (FIG. 1). The voltage output from the line selection unit 102 is input to the line-side current detection unit 110 through the wirings Sx1 to Sxm. The current detection unit 110 includes current detection resistors Rsx1 to Rsxm, and a voltmeter (V) for measuring a voltage value generated between both ends of these resistors. Accordingly, the control unit 104 measures the voltage value generated at each of the current detection resistors Rsx1 to Rsxm corresponding to each row wiring with each voltmeter, and divides each of the voltage values by the resistance value of each resistor. Thus, the value of the current flowing through each row wiring can be obtained.

FIG. 4B is a block diagram showing the configuration of the current detection unit 107 (FIG. 1) on the pixel selection side. The voltage signal output from the pixel voltage output voltage amplifier 111 (FIG. 1) passes through the wirings Sy1 to Syn and passes through the current detection unit 107.
Is input to This current detection unit 107 includes a detection resistor R
It has a voltmeter (V) for measuring voltages generated at both ends of these resistors from sy1 to Rsyn. By these,
The control unit 104 receives, from each voltmeter, a voltage value generated at each of the current detection resistors Rsy1 to Rsyn corresponding to each column wiring, and divides each of these voltage values by the resistance value of each resistor. The value of the current flowing through each row wiring can be determined.

In the example shown in FIG. 2 and FIG.
Since the element F (1,2) in the second row and the second column is selected and the other lines are grounded, no current flows through the elements other than the element in the first row and the second column. Therefore, a voltage is generated only at both ends of the resistor Rsx1 in the first row in FIG. 4A and the resistor Rsy2 in the second column in FIG. 4B, and if the voltage value is V2, the voltage is generated in the first row. The current I1 flowing through the row wiring of the second column can be calculated by the following formula: I1 = V2 / Rsx1 The current I1 flowing through the second column wiring can be calculated by the following equation: I1 = V2 / Rsy2. Note that Rsx1
To Rsxm and Rsy1 to Rsyn are equal to the current If
Is set to a sufficiently low value so as not to affect the voltage applied to the surface conduction electron-emitting device substrate 101 due to the voltage drop when the current flows. These voltmeters can be converted into digital values by an A / D converter and output to the control unit 104, respectively.

As described above, the value of the current flowing for each surface conduction element can be monitored from both sides of the row wiring and the pixel selection (column wiring) side.

Further, as shown in FIG. 1, by grounding all the column wirings in the pixel-side selection section 111a, the value of the current flowing through the wiring can be measured for each row wiring. Further, by grounding all the row wirings of the line selection unit 102, the current value can be measured for each column wiring.

FIG. 24 is a schematic diagram showing voltage application in this embodiment. Only the elements in the second row are connected to the row-side drive voltage source, and the other rows are connected to the ground. The column side is connected to a column side drive voltage source.

Next, a method of determining a compensation voltage output from the control unit 104 (FIG. 1) to the pixel selection side will be described. First, for simplicity, a voltage drop when a voltage is applied from the row wiring side will be described. FIG. 5 shows that all the elements in the i-th row of the surface conduction electron-emitting elements wired in m rows × n columns are
It is a schematic diagram which shows the case where a voltage is applied from a row wiring.

Now, assuming that the voltage value applied to the i-th row wiring is Vf, the wiring resistance is R1, R2, R3,..., Rn, the resistance of each surface conduction electron-emitting device is r1, r2,
r3, ..., rn. Here, it is assumed that all other row wirings are grounded.

The wiring resistance of the i-th row (one line) is R_li
Assuming ne_i, R_line_i = ΣRj (where j = 1 to n). Here, if the current flowing in the i-th row is If, and the current flowing in the element in the j-th column is if (j), the voltage V (1) applied to the element in the first column is V (1) = Vf− R1 × If. This is because the voltage applied to the element in the first column is lower than the voltage Vf to be applied by R1 × I
It can be seen that it is smaller by f (V). Similarly,
The voltages V (2), V applied to the elements in the second and third columns
(3) is as follows: V (2) = V (1) −R2 × (If−if (1)) V (3) = V (2) −R3 × (If−if (1) −if
(2)) is calculated by Thus, the elements in the k-th column (where k ≦
The voltage V (k) applied to (n / 2) is: V (k) = V (k−1) −Rk × (If−Σif
(J)) (where j = 1 to k-1). Therefore, the voltage applied to the element in the k-th column is Vf−V (k) = Vf−V (k−1) + Rk × (If−Σif (j)) (where j = 1 to Vf). k-1) = Vf-V (k-2) + Rk-1.times. (If-.DELTA.if (j)) + Rk.times. (If-.SIGMA.if (j)) (where the first .DELTA.if (j) is j = 1 to k −2, the second Δif (j) is the sum of j = 1 to k−1) = If × (R1 + R2 +... + Rk) − (R2 × if (1) + R3 × (if (1) + if (2)) ) +... + Rk × Σif (j)) (where j = 1 to k−1). The voltage value Vfdk shown in FIG. 20 is the voltage drop (Vf-V
(K)), and by applying this voltage drop from the column wiring, it is possible to perform driving in which the voltage drop due to wiring resistance is compensated.

The wiring resistances R1, R2, R3,.
It is determined by measuring the actual resistance. Also, i
The current If flowing in the row and the current if (j) flowing in the j-th column
Can be measured by the line-side current detector 110 (FIG. 1) and the pixel-side current detector 107 (FIG. 1) during driving. Therefore, during this driving, these currents I
If f and if (j) are measured, it is possible to determine and apply a compensation voltage according to the driving state (first voltage application step).

Next, a method of determining a compensation voltage in the case of performing image display by performing line-sequential driving will be described. First, voltage application during line-sequential driving will be described. FIG. 6 shows m rows × n
FIG. 7 is a schematic diagram showing a case where only elements in odd-numbered columns among the elements in the i-th row of the surface conduction electron-emitting elements wired in columns are driven. Here, for simplicity, it is assumed that the row wiring resistance is extremely small and can be ignored. It is also assumed that all other row wirings are grounded (n is an even number).

The voltage setting at the time of driving is, as shown in the static characteristics of FIG. 22, the threshold voltage Ve (hereinafter referred to as V_) of the element current If.
In the following, the fact that almost no element current flows is used. For the drive element, the drive voltage Vf is
Further, a voltage equal to or lower than V_if_th may be applied to the non-driving element.

In order to apply the drive voltage Vf to the element in the i-th row and the odd-numbered column, Vf / 2 is applied from the row wiring side, and -Vf / 2 is applied to the element in the odd-numbered column, so that Vf / 2 <V_if_th. Is set as follows. In the present embodiment, specifically, since the threshold voltage V_if_th is 8 [V], Vf is set to 14 [V],
Vf / 2 may be set to 7 [V]. The electron emission threshold Ve is also 8 [V] in the present embodiment.

Since the device current-voltage characteristics used in the present embodiment are prepared with good uniformity, i (1) = i (3) = i (5) =... = I (n-1) ) = I
f0 (const) = 2 [mA] i (2) = i (4) = i (6) =... = i (n) = 0 [m
A].

Next, a case where there is an effect of the row wiring resistance will be considered. The driving is line-sequential driving as in the above, and shows a case in which only the elements in the i-th row and the odd-numbered columns are driven. FIG.
Is i of a surface conduction electron-emitting device wired in m rows × n columns.
It is a schematic diagram which shows the case where only the element of an odd-numbered column among the elements of a row is driven. Further, the wiring resistance is set to R1, R2, R3,
.., Rn is the resistance of each surface conduction electron-emitting device as r.
1, r2, r3,..., Rn (n is an even number).

Here, it is assumed that all other row wirings are grounded. The voltages applied to the row wirings are Vyl and Vyr, and the voltages applied from the column side are Vx (1), Vx (2),
Vx (3),..., Vx (n), and the current flowing into each element is denoted by i (1), i (2), i (3),.
In addition, the current flowing into the row wiring is measured from both ends of the row wiring, and is set as i_left and i_right, respectively.

In order to apply the drive voltage Vf to each of the odd-numbered elements, a voltage drop due to the wiring resistance is taken into consideration.
It is necessary to set as follows. Each element has a drive voltage V
Since f becomes current If0 and becomes 0 below V_if_th, the current flowing in each column is i (1) = i (3) = i (5) =... = i (n−1) = I
f0 (const) = 2 [mA] i (2) = i (4) = i (6) =... = i (n) = 0 [m
A]. In this case, the voltage on the row wiring is Vyl = Vyr = Vf / 2 = 7 [V] V (1) = Vf / 2−R1 × i_left V (2) = Vx (1) V (3) = V ( 2) -R3 × (i_left-i (1) -i
(2)) V (4) = V (3) −R4 × (i_left−i (1) −i
(2) −i (3)): V (k) = V (k−1) −Rk × (i_left−Σi
(J)) (where j = 1 to k-1), and the voltage applied from the column wiring is Vx (1) = V (1) -Vf = -Vf / 2-R1.times.i_le
ft Vx (2) = 0 Vx (3) = V (3) −Vf = V (2) −R3 × (i_le
ft-i (1) -i (2))-Vf: When k is an even number, Vx (k) = 0 When k is an odd number, Vx (k) = V (k) -Vf = V (k-1) ) −Rk ×
(I_left−Σi (j)) − Vf (where j = 1 to k−1).

In order to emit electrons only to the odd-numbered elements in the i-th row, electrons in rows other than the i-th row must not be emitted. Therefore, Vx (1) <V_if_th (= Ve) = 8 [V Vx (2) <V_if_th (= Ve) = 8 [V] Vx (3) <V_if_th (= Ve) = 8 [V]: Vx (k) <V_if_th (= Ve) = 8 [V] (k = 1
To n). In the present embodiment, the above-mentioned necessary conditions can be satisfied. The row-side voltage V as described above
yl, Vyr, column-side voltages Vx (0), Vx (2), ..., Vx
By using (k), voltage compensation can be performed by line-sequential driving.

In the above description, the voltage compensation for driving the i-th row and the odd-numbered column is performed by the currents i_left and i_righ flowing from the row direction.
The method of calculating from t was described. Even without performing the current measurement, the current flowing through the surface conduction electron-emitting device can be uniquely determined by the value of the drive voltage Vf. For this reason, the voltage value applied from the column side is
4 (FIG. 1) can be calculated in accordance with the display pattern secured. There is also a method in which a compensation voltage calculation corresponding to the display pattern secured in the line memory 124 is held in a recording circuit in advance and driven. The driving waveform used in the present embodiment will be described later (FIG. 8).

Next, a method for detecting a reactive current of the multi-electron source substrate 101 using the driving method of the present embodiment will be described. In the display panel used in the present embodiment, due to breakage of the vacuum vessel and aging of the display panel,
In some cases, the vacuum atmosphere is deteriorated, and the atmosphere containing an organic substance is generated. In this case, as in the case of the activation, a voltage is applied to the non-selected elements, so that a reactive current may be generated. In the case of FIG. 7 described above, the even-numbered elements in the i-th row and the elements other than the i-th row correspond to the non-selected elements.

However, when the voltage is continuously applied to the column wirings, the voltage (Vassist) applied from these column wirings is continued.
_j) will continue to be applied to all the elements connected to the second and subsequent row wirings, and the VCNR characteristics of the above-described elements will cause a reduction in resistance, causing a reactive current to flow.

Here, a method of preventing the multi-electron source from reducing the resistance by the present inventors will be described with reference to FIG. When a voltage pulse of a voltage drop rate (falling pulse) of 10 [V / sec] or more is applied to the surface-conduction emission element having reduced resistance, the IV consisting of the regions A and B in FIG.
The state changes to a high resistance state different from the static characteristic.

Here, the high resistance state refers to a state in which the element complies with the IV characteristic along the dynamic characteristic for a finite time. For example, with respect to the surface conduction electron-emitting device having the IV characteristic shown in FIG. 22, the peak value Vd and the voltage drop rate 10 [V /
Seconds] or more immediately after the voltage pulse is applied.
The -V measurement indicates a high resistance state as indicated by If (Vd) in FIG. Even after the transition to the high resistance state, if Vd is applied to the element, the emission current Is
It is possible to obtain Moreover, as is apparent from the characteristic shown by the solid line If (Vd), Ve
Even if the following voltage is applied, the current If flowing through the element is greatly reduced as compared with the static characteristic indicated by the dotted line. The high resistance state of such an element is maintained for a finite time after the application of the voltage pulse (this time is referred to as Th.
Thereafter, the characteristic returns to the IV static characteristic shown in FIG. Therefore, when it is necessary to maintain the high resistance state for a desired period, by repeatedly applying the voltage pulse again while the high resistance state is maintained, the holding time of the high resistance state can be reduced. The period can be extended.

Therefore, according to the present embodiment, the I-
On the surface conduction electron-emitting device substrate 101 having V static characteristics, a voltage pulse (hereinafter, referred to as a high-resistance pulse) having a voltage drop rate of 10 [V / sec] or more is applied in advance (second voltage application). Step) to obtain the IV of the device.
Change static characteristics to different states. That is, by causing the element to transition to the high resistance state, the reactive current flowing through the above-mentioned half-selected element can be reduced, and the power consumption of the device at the time of activation can be greatly reduced. Note that the upper limit of the voltage drop rate of the resistance increasing pulse is practically 10 to the 10th power [V / sec].

According to the characteristics of the surface conduction electron-emitting device described above, by applying a high-resistance pulse to the entire electron source substrate 101 at each Thr time, the resistance of the half-selection device can be prevented from being lowered, and Activation can be performed without deteriorating or destroying the substrate 101.

The pulse introduced to prevent the surface conduction electron-emitting device from having a low resistance is hereinafter referred to as a refresh pulse. Here, a method for detecting resistance reduction and a method for introducing a pulse according to the present embodiment will be specifically described.

The currently driven line is the i-th line. When driving is performed in units of rows, it is possible to measure the current at the time of driving by the row-side current detector 110 and the column-side pixel-side current detector 107 from FIG.

The current flowing in the selected row and column 1 is measured by the line-side current detector 110. The line-side current at this time is assumed to be If_line_i (where i = 1, 2,..., M). The pixel side current detection unit 107 can measure the value of the current flowing through each element. The pixel side current at this time is If_gaso_
j. (Where j = 1, 2, 3,..., N) Even if a voltage is applied to a non-selected element from the pixel side, if the resistance of the element is not reduced, If_line_i = If_gaso_1 + If
_gaso_2 + If_gaso_3 + ... + If_gaso_n = ΣIf_gaso_j
(However, j = 1 to n).

However, if the resistance of the non-selected element becomes remarkable due to the pixel side voltage, the leakage current of the element connected to the column wiring increases, so that If_line_i <ΣIf_gaso_j (where j = 1 to n ) And the magnitude of the leakage current If_leak_i in the column wiring when the i-th row is activated is If_leak_i = (ΣIf_gaso_j) −If_line_i (where
j = 1 to n). By using the leak current If_leak_i, it is possible to examine the state of the surface conduction type element formed in a simple matrix having low resistance.

In the present embodiment, this leakage current If
If the magnitude of _leak_i is a certain threshold (hereinafter, If_refresh_th
), A refresh pulse is introduced for the first time. Note that this leakage current threshold If_ref
resh_th is, specifically, several hundred [μA] to several [A], and this value varies depending on the material of the element and the manufacturing process. In the present embodiment, the threshold value If_refresh_th is set to 100 [mA].

The timing for introducing the high-resistance pulse is based on the blanking period of the image signal. Generally, NT
Starting with the SC signal, signals for transmitting image information include:
There is a synchronization signal portion that does not include image data such as luminance and color. In the present embodiment, a high resistance pulse is applied to the surface conduction electron-emitting device using this period.

For example, in the case of the NTSC signal, a vertical blanking period of about 1.27 [msec] and a horizontal blanking period of about 10.9 [μsec] are provided. The high resistance pulse may be applied using both periods.

FIG. 8 shows a high-resistance pulse and a driving waveform in this embodiment. FIG. 8 shows a waveform for driving the element in the first row and the first column. From the row wiring side, a pulse width of 60 [μsec] and a pulse period of 16.7
[Msec], a pulse of voltage (Vf / 2) 7 [V]
From the column wiring side, pulse width 30 [μsec], pulse period 16.7 [msec], voltage (Vx_drive) 7.5 [V]
Pulse is applied. Anode voltage Hv when attached
Is always applied. Leakage current when driving the first row
Since If_leak_1 was measured to be 200 [mA], a resistance increasing pulse was introduced from the wiring in the first row during the vertical retrace period. Pulse width 60 [μsec], voltage (Vrefresh)
8 [V], the slew rate of one pulse is 8 [V / μs
c].

The resistance increasing pulse is generated by the power supply 1 shown in FIG.
03, and at this time, the line selection unit 102 is controlled to select all the row wirings. Also, at this time,
The pixel-side selection unit 111a is controlled to select all the row wirings. At this time, the pixel-side selection unit 111a
Is switched off and dropped to ground. Conversely, a method is also conceivable in which all the column wirings are selected by the pixel-side selection unit 111a and all connections in the line selection unit 102 are grounded, thereby introducing a high-resistance pulse.

As described above, the image display driving is performed by sequentially selecting and driving the row wirings while appropriately increasing the resistance of the half-selected elements.

FIG. 9 is a flowchart showing the processing operation of the image display drive control unit 104 according to the present embodiment. First, in step S1, using the sync separation circuit, the NTSC
The vertical synchronizing signal VD, the horizontal synchronizing signal HD, and the luminance signal are separated from the image signal. Next, in step S2, the luminance signal separated by the sync separation circuit is digitized by an A / D converter, and data for one line of an image is subjected to serial / parallel conversion. When step S2 ends, the process moves to step S3, where data is written to the line memory. Next, in step S4, pulse width modulation data is generated according to the luminance data of the line memory.
In step S4, a calculation is performed in consideration of the compensation voltage so that the influence of the voltage drop in the row wiring can be compensated.

After the calculation is completed, in step S5, the drive voltage for the first row is output from the row side and the column side. Here, the first row wiring is selected, and the voltage determined in step S4 is output.

Next, in step S6, it is determined whether it is the drive end time of the selected line. Here, 60 [μsec]
Is the drive end time. If it is before the drive end time,
The process proceeds to step S7 and step S9. If the drive end has passed, the process proceeds to step S10, and it is determined whether or not the current time is a vertical blanking period.

Step S7 is a step of measuring a leakage current during driving. At the time of applying the driving voltage in step S5, the leak current is measured to determine whether a high-resistance pulse is necessary. If the measured current I_leak_i is larger than the leak current threshold I_refresh, the low resistance flag is turned on in step S8. If the measured current I_leak_i is smaller than the leak current threshold, the process proceeds to Step S6.

Next, step S9 will be described. In this sequence, the luminance data of the next row wiring is secured in the line memory, the luminance is converted into pulse width modulation data, and then the voltage setting that compensates for the voltage drop due to the wiring resistance is performed. This sequence includes steps S1,
This is the same as the sequence of S2, S3, and S4.

In step S10, it is determined whether or not it is a retrace period. The row driven in step S6 is the n-th row (= 2
If it is (line 40), it is determined that it is a retrace period. If it is the retrace period, the process proceeds to step S12. If it is not the retrace period, the process proceeds to step S11, where the luminance data of the second row (next row) is set, and the row wiring of the second row is selected. The luminance data used here is the one calculated in step S9.

Step S12 is a step for checking the result of the determination in step S8. Step S8
If the low resistance flag is ON in any of the rows, the process proceeds to step S13.

Step S13 is a sequence for applying a resistance increasing pulse. A high-resistance pulse is applied to all the row wirings.
Set the luminance data of the line.

As described above, if the magnitude of the leakage current of the half-selected element is detected as a matrix-like element as a whole and driven while increasing the resistance, it is possible to further reduce the input power in the driving step. Become. Therefore, thermal destruction of the surface conduction element can be further prevented, and the amount of power consumption of the current supply device can be reduced.

The surface conduction electron-emitting device substrate of the present embodiment has two-sided wiring, but the same method can be applied to a substrate with one-sided wiring. It goes without saying that a high-quality image forming apparatus has been realized.

In this embodiment, the high-resistance pulse is applied during the flyback period. However, it goes without saying that the pulse may be applied when the power of the image display device that does not display an image is turned on or the power is turned off. .

In the present embodiment, the measurement of the leakage current
Although a pulse voltage for image display is used, a leak current measurement detection pulse may be introduced using a vertical retrace period and a horizontal retrace period of an image signal.

[Embodiment 2] This embodiment is different from Embodiment 1 in the method of applying a voltage to non-selected elements.
Here, only the portions different from the first embodiment will be described. Embodiment 2 is different from Embodiment 1 in that
These are a method of applying a voltage to a non-selected element and a method of measuring a leak current. By using this embodiment, the amount of power consumption applied to the non-selected elements can be suppressed, and the leakage current can be easily measured.

First, a method of applying a voltage to a non-selected element will be described. FIG. 10 is a schematic diagram illustrating voltage application according to the present embodiment. FIG. 10 shows that the second row is being driven, and the other rows are non-selected elements. Apply voltage from the Vuso power supply to the lines other than the second line.

Next, FIG. 11 is a diagram showing a circuit configuration of the line selecting section of the present embodiment. In FIG. 11, a line is connected from the control unit 104 to the Vuso power supply, or the power supply 1
03 is controlled. In FIG. 11, the power supply 1
03, only the second row (Sx2) is selected and connected to the row wiring terminal Dx2. The lines other than the second line are connected to the Vuso power supply.

FIG. 12 is a driving waveform diagram of the present embodiment. FIG. 12 shows waveforms for driving the elements in the second row and the first column. From the row wiring side, a pulse width of 60 μsec
c], pulse period 16.7 [msec], voltage (Vf /
2) A pulse of 7 [V] is applied with a pulse width of 30 from the column wiring side.
[Μsec], a pulse period of 16.7 [msec], and a voltage (Vx_drive) of 7.5 [V] are applied. 2
The voltage Vuso is applied to all the row wirings other than the row, so that the leakage current caused by the voltage from the column side is reduced.

The anode voltage Hv in the attached drawing is always applied. When driving the second row, the leakage current If_leak_1
Was measured to be 200 [mA], and a high-resistance pulse was introduced from the wiring in the first row in the vertical blanking period.
Pulse width 60 [μsec], voltage (Vrefresh) 8
[V], and the pulse slew rate was 8 [V / μsec].

In the present embodiment, the set value of the voltage Voso is such that the maximum voltage applied from the column side is Voso. In the case of driving only the odd-numbered second row in an m-row × n-column simple matrix (m is 240 and n is 720) similar to the first embodiment, (n / 2-1) Column,
The voltage applied to the (n / 2 + 1) th column is set. Vuso = Vx (n / 2-1) = Vx (n / 2 + 1) (where m is 240 and n is 720)

Next, a method of measuring a leak current and a method of determining a reduction in resistance will be described. As the leak current, the leak current flowing to the non-selected row is measured by the ammeter of the Vuso power supply.
By using this method, the currents flowing through the non-selected rows can be collectively measured. This leakage current is 200
When the current exceeds [mA], a high-resistance pulse is introduced. With the above-described configuration, it is possible to perform a drive capable of removing a leak current with a simpler measurement system.

[Embodiment 3] Next, the structure of a display panel of an image display device to which the electron source substrates of Embodiments 1 and 2 are applied and a method of manufacturing the same will be described with reference to specific examples. FIG. 13 is an external perspective view of a display panel 1000 using the electron source substrate 101 of the present embodiment, in which a part of the display panel 1000 is cut away to show the internal structure. In the figure, 1005 is a rear plate, 1006 is a side wall, 1007 is a face plate.
05 to 1007 form an airtight container for maintaining the inside of the display panel 1000 in a vacuum. In assembling this airtight container, it is necessary to seal the joint of each member to maintain sufficient strength and airtightness,
For example, frit glass was applied to the joint, and baked in air or a nitrogen atmosphere at 400 to 500 degrees Celsius for 10 minutes or more to achieve sealing. A method for evacuating the inside of the airtight container will be described later.

A substrate 101 is fixed to the rear plate 1005. On this substrate 101, n × m surface conduction electron-emitting devices 1002 are formed (here,
n and m are positive integers of 2 or more, and are appropriately set according to the target number of pixels to be displayed. For example, in a display device for displaying high-definition television, n =
It is desirable to set the number to 3000, m = 1000 or more. In the present embodiment, n = 3072, m = 1
024). These n × m surface conduction electron-emitting devices are arranged in a simple matrix by m row wirings 1003 and n column wirings 1004. These substrates 101,
Electron-emitting device 1002, row and column wirings 1003, 10
The part constituted by 04 is called a multi-electron source.

In this embodiment, the configuration is such that the substrate 101 of the multi-electron source is fixed to the rear plate 1005 of the hermetic container. However, when the substrate 101 of the multi-electron source has a sufficient strength. The substrate 101 of the multi-electron source may be used as a rear plate of the hermetic container.

A fluorescent film 1008 is formed on the lower surface of the face plate 1007. Since this embodiment is a color display device, phosphors of three primary colors of red, green, and blue used in the field of CRT are separately applied to a portion of the fluorescent film 1008. The phosphors of each color are separately applied in a stripe shape, for example, and a black conductor is provided between the stripes of the phosphors. The purpose of providing these black conductors is to prevent the display color from being shifted even if there is a slight shift in the electron beam irradiation position, and to prevent reflection of external light to prevent a reduction in display contrast. This is to prevent charge-up of the fluorescent film by the electron beam. Although graphite is used as a main component of the black conductor, any other material may be used as long as it is suitable for the above purpose. Note that when a monochrome display panel is formed, a single-color phosphor material is
And a black conductive material need not always be used.

Also, a metal back 1009 known in the field of CRTs 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 to improve the light utilization rate by mirror-reflecting a part of the light emitted from the fluorescent film 1008, to protect the fluorescent film 1008 from the collision of negative ions, to accelerate the electron beam. In order to function as an electrode for applying a voltage,
This is to make 8 act as a conductive path for excited electrons. The metal back 1009 is formed by forming a fluorescent film 1008 on the face plate substrate 1007, smoothing the surface of the fluorescent film, and vacuum-depositing Al (aluminum) thereon. Note that the fluorescent film 1008
When a low-voltage phosphor material is used, the metal back 109 is not used.

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

Dx1 to Dxm and Dy1 to Dyn and Hv are electric connection terminals having an airtight structure provided for electrically connecting the display panel 1000 to an electric circuit (not shown). Here, the row terminals Dx1 to Dxm are the row wirings 1003 of the multi-electron source, the column terminals Dy1 to Dyn are the column wirings 1004 of the multi-electron source, and Hv is the face plate substrate 100.
7 is electrically connected to the metal back 1009.

In order to evacuate the inside of the hermetic container to a vacuum, after assembling the hermetic container, an exhaust pipe (not shown) and a vacuum pump are connected, and the inside of the hermetic container is about 10 −7 [torr]. Evacuate to vacuum. 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 10 −5 or 10 −5 due to the adsorption action of the getter film. The degree of vacuum is maintained at minus 7th power [torr]. The basic configuration and manufacturing method of the display panel 1000 according to the embodiment of the present invention have been described above.

[0122]

As described above, according to the present invention, the following effects can be obtained. By detecting the magnitude of the leakage current of the half-selected element as the entire element in a matrix and driving while increasing the resistance, it becomes possible to further reduce the input power in the driving step. as a result,
Thermal destruction of the surface conduction element can be further prevented, and the amount of power consumption of the current supply device can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of an energizing device for a surface conduction electron-emitting device according to Embodiment 1 of the present invention.

FIG. 2 is a diagram illustrating a circuit configuration of a line selection unit according to the first embodiment.

FIG. 3 is a circuit diagram showing a circuit configuration of a pixel selection side output voltage amplifier according to the first embodiment;

FIG. 4 is a block diagram illustrating a configuration of a line-side current detector and a pixel-selection-side current detector according to the first embodiment; FIG. 3A is a circuit diagram illustrating a configuration of a line-side current detection unit. FIG. 4B is a block diagram illustrating a configuration of a current detection unit on a pixel selection side.

FIG. 5 is a schematic diagram showing a case where a voltage is applied from a row wiring to all of the i-th row elements of the surface conduction electron-emitting devices wired in m rows × n columns according to the first embodiment;

FIG. 6 is a schematic diagram showing a case in which, of the surface conduction electron-emitting devices arranged in m rows × n columns according to the first embodiment, only the devices in the odd columns among the i-th devices are driven.

FIG. 7 is a schematic diagram showing a case where only the odd-numbered column elements of the i-th row elements of the surface conduction electron-emitting devices wired in m rows × n columns according to the first embodiment are driven.

FIG. 8 is a diagram showing driving waveforms used in the first embodiment.

FIG. 9 is a flowchart showing a processing operation of a control unit for driving image display according to the first embodiment;

FIG. 10 is a schematic diagram showing voltage application according to a second embodiment.

FIG. 11 is a diagram illustrating a circuit configuration of a line selection unit according to the second embodiment.

FIG. 12 is a drive waveform diagram according to the second embodiment.

FIG. 13 is an external perspective view of a display panel using the electron source substrate according to the third embodiment.

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

FIG. 15 is a diagram showing an electrical wiring method of a multi-electron source in which a large number of surface conduction emission devices are two-dimensionally arranged and these devices are wired in a matrix.

FIG. 16 is a schematic diagram of a measurement system of an element current If and an emission current Ie flowing through the surface conduction electron-emitting device during the activation process.

FIG. 17 is a diagram showing a relationship between an elapsed time in an activation process and an element current If and an emission current Ie in the measurement system of FIG. 16;

FIG. 18 is an equivalent circuit diagram when a row wiring of a second row of the electron-emitting devices wired in a simple matrix is activated.

FIG. 19 is a diagram showing a waveform of an applied voltage signal in an activation process.

FIG. 20 is a diagram illustrating a voltage applied to each element and a compensation voltage applied from a column wiring in an activation process. (A) In the simple matrix wiring of m rows × n columns shown in FIG. 18, the voltage applied to each element when the element in the second row is activated with a voltage value Vf0 is schematically shown. FIG. FIG. 4B is a diagram illustrating an example of compensating for a voltage drop by a voltage applied from an electrode on a column wiring side.

FIG. 21 is a diagram illustrating an element selected and activated in an activation process and a half-selected element based on a compensation voltage.

FIG. 22 is a diagram showing typical IV characteristics of a surface conduction electron-emitting device.

FIG. 23 is a diagram showing an equivalent circuit in an image display step.

24 is a diagram showing a waveform of an applied voltage signal in the driving of FIG.

[Explanation of symbols]

101: surface conduction type emission element substrate, 102: line selection unit, 103: power supply, 104: control unit, 104a: timer, 107: pixel selection side current detection unit, 111: pixel selection side output voltage amplifier, 111a: pixel side Selection unit, 121:
Sync separation circuit, 122: A / D converter, 123: shift register, 124: line memory, 125: pulse width modulator, 150: control signal from the control unit 104 to the line selection unit 102, 151: from the control unit 104 Control signal to the pixel selection side output voltage amplifier 111, 152: voltage amplifier,
154: a control signal from the line side current detection unit 110 to the control unit 104, 155: a control signal from the pixel selection side current detection unit 107 to the control unit 104, VD: a vertical synchronization signal, H
D: horizontal synchronization signal; Dx1 to Dxm: row wiring terminals of the electron source substrate 101; Dy1 to Dyn: column wiring terminals of the electron source substrate 101; Input wiring of the pixel selection side current detection unit 107, Cy1 to Cyn: control signal terminals input to the pixel selection side output voltage amplifier 111, 700: about 10 [V / sec] in the IV characteristics of the surface conduction electron-emitting device Dynamic characteristics obtained at the above voltage sweep speed, 701: Dynamic characteristics when sweeping at the maximum voltage V2 in the IV characteristics of the surface conduction electron-emitting device, 1000: Display panel, 1001, 1101, 3
001: substrate, 1002, 4001: surface conduction electron-emitting device, 1003: row wiring, 1004: column wiring, 1005:
Rear plate, 1006: side wall, 1007: face plate, 1008: fluorescent film, 1009: metal back,
1102, 1103: device electrode, 1104, 3004:
Conductive thin film, 1111, 1116: ammeter, 1112:
Activation power supply, 1113, 3005: electron emission section, 111
4: anode electrode, 1115: DC high-voltage power supply, 400
2: row wiring, 4003: column wiring, 4004, 4005:
Wiring resistance.

Claims (11)

[Claims] 1. An electron source comprising: a plurality of row wirings, a plurality of column wirings, and a plurality of electron-emitting devices provided on a substrate, wherein the plurality of row wirings and the plurality of column wirings are arranged in a matrix. In the driving method, a current detection step of detecting a current flowing through the plurality of electron-emitting devices; and selecting an arbitrary row wiring from among the plurality of row wirings, and selecting the selected row with respect to the plurality of column wirings. A first voltage application step of applying a voltage to compensate for the effect of a voltage drop due to wiring, and a predetermined voltage applied to at least a specific one of the plurality of electron-emitting devices connected to the row wiring. And a second voltage application step of applying a voltage. 2. The method according to claim 1, wherein the first voltage applying step selects any one of the plurality of row wirings or the plurality of column wirings and the plurality of column wirings or the plurality of row wirings. Applying a voltage to compensate for the effect of a voltage drop caused by the selected row wiring or the column wiring on the wiring; and the second voltage applying step includes connecting to the row wiring or the column wiring. The method according to claim 1, wherein a predetermined voltage is applied to at least a specific one of the plurality of electron-emitting devices. 3. The electron source according to claim 1, wherein the first voltage applying step is a step of applying a voltage according to a current value detected by the current detecting step. Drive method. 4. The method according to claim 1, wherein the current detecting step is a step of detecting a current flowing in the row wiring and / or the column wiring when the voltage is applied in the first voltage applying step. A method for driving an electron source according to any one of the above. 5. The electron source according to claim 1, wherein the second voltage applying step is a step of increasing the resistance of one or a plurality of the electron-emitting devices. Drive method. 6. The method of driving an electron source according to claim 1, further comprising a step of increasing the amount of electrons emitted from the electron-emitting device by driving under an activating substance source. The method for driving an electron source according to any one of the above. 7. The method according to claim 6, wherein the activating substance source is carbon or a carbon compound. 8. The method according to claim 1, wherein in the first voltage applying step, a voltage is applied by sequentially selecting the plurality of row wirings and / or the plurality of column wirings.
8. The method for driving an electron source according to any one of claims 7 to 7. 9. The method according to claim 9, wherein the second voltage applying step applies a predetermined voltage to all of the plurality of electron-emitting devices connected to the row wiring and / or the column wiring. The method for driving an electron source according to claim 1. 10. The method according to claim 1, wherein the second voltage applying step applies a predetermined voltage to one or more of the electron-emitting devices. Method of driving the electron source. 11. An electron source having a plurality of row wirings, a plurality of column wirings, a plurality of electron-emitting devices, an electron source arranged in a matrix with the plurality of row wirings and the plurality of column wirings on a substrate, A method for driving an image display device comprising: a fluorescent film irradiated with electrons from an electron source; wherein the image display device is driven by the method for driving an electron source according to any one of claims 1 to 10. Characteristic driving method of an image display device.