JP2002203478A - Electron source, adjustment method and manufacturing method therefor, image formation device, adjustment method therefor and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the electron emission amount from each electron element from easily dispersing by the influence of voltage drop in driving and to simplify the structure of a driving circuit. SOLUTION: Substantially uniform electron emission is realized in actual driving by adjusting a voltage-emission current characteristic of each electron emission element so as to eliminate the influence of voltage drop due to wiring resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electron source, a method for adjusting the electron source, and a method for manufacturing the same.

[0002]

2. Description of the Related Art The inventors of the present application have studied an electron source using an electron-emitting device and an image forming apparatus using the same, and have already proposed some of them.

[0003] Two types of electron-emitting devices are known, a hot cathode device and a cold cathode device. Of these, for cold cathode devices,
For example, field emission devices, metal / insulating layer / metal emission devices, surface conduction emission devices, and the like are known.

[0004] Among the cold cathode devices, a surface conduction electron-emitting device (hereinafter sometimes simply referred to as a device) is a thin film of SnO2, Au, In2O3 / SnO2, carbon or the like formed on a substrate. This utilizes a phenomenon in which electron emission occurs when a current is passed in parallel to a plane. FIG. 1 shows an example of a typical element configuration. In the figure, 3001
, A substrate; and 3004, a conductive thin film made of metal oxide formed by sputtering. The conductive thin film 3004 is formed in an H-shaped planar shape as shown. By subjecting the conductive thin film 3004 to an energization process called energization forming, an electron emission portion 3005, that is, a surface conduction type emission element is formed. The interval L in the figure is 0.5
１1 [mm] and the width W are set at 0.1 [mm]. In addition, for convenience of illustration, the electron emitting portion 3005 is shown in a rectangular shape at the center of the conductive thin film 3004, but this is a schematic one, and the position and shape of the actual electron emitting portion are faithfully represented. Not necessarily.

FIG. 2 shows typical examples of (emission current Ie) versus (device applied voltage Vf) characteristics and (device current If) versus (device applied voltage Vf) characteristics of a surface conduction electron-emitting device. Note that the emission current Ie is significantly smaller than the element current If, and it is difficult to show them on the same scale. In addition, these characteristics are changed by changing design parameters such as the size and shape of the element. Therefore, each of the two graphs is shown in arbitrary units.

The surface conduction electron-emitting device has the following three characteristics regarding the emission current Ie. 1. When a voltage higher than a certain voltage (referred to as a threshold voltage Vth) or higher is applied to the element, the emission current Ie sharply increases. On the other hand, at a voltage lower than the threshold voltage Vth, the emission current Ie is hardly detected. That is, the emission current I
e is a non-linear element having a clear threshold voltage Vth. 2. Since the emission current Ie changes depending on the voltage Vf applied to the element, the magnitude of the emission current Ie can be controlled by the voltage Vf. 3. Since the response speed of the current Ie emitted from the element with respect to the voltage Vf applied to the element is high, the amount of charge of the electrons emitted from the element can be controlled by the length of time during which the voltage Vf is applied.

The surface conduction electron-emitting device has an advantage that a large number of devices can be formed over a large area because the structure is simple and the production is easy. Therefore, an image forming apparatus such as an image display device and an image recording device, an electron beam source, and the like, to which the surface conduction electron-emitting device is applied, have been studied.

[0008] The inventors have tried surface conduction type emission devices of various materials, manufacturing methods and structures. Further, research has been conducted on a multi-electron beam source (also simply referred to as an electron source) in which a large number of surface conduction electron-emitting devices are arranged, and on an image display device using the electron source.

For example, an electron source based on the electrical wiring method shown in FIG. 3 has been tried. 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. In the figure, they are shown as wiring resistances 4004 and 4005. The above-described wiring method is called simple matrix wiring. For convenience of illustration, the matrix is shown as a 6 × 6 matrix, but the size of the matrix is not limited to this.

In an electron source in which elements 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 emission current. At the same time, a high voltage is applied to an anode electrode (not shown).

For example, in order to drive an arbitrary element in the matrix, a selection voltage Vs is applied to the terminal of the row direction wiring 4002 of the selected row, and at the same time, to the terminal of the row direction wiring 4002 of the non-selected row. Applies a non-selection voltage Vns.
In synchronization with this, modulation voltages Ve1 to Ve6 for outputting an emission current to terminals of the column direction wiring 4003 are applied.
According to this method, the elements to be selected include Ve1-Vs-
A voltage of Ve6-Vs is applied, and voltages of Ve1-Vns to Ve6-Vns are applied to unselected elements.
Here, Ve1 to Ve6, Vs, and Vns are selected by appropriately setting voltages so that a voltage equal to or higher than the threshold voltage Vth is applied to a selected element and a voltage equal to or lower than the threshold voltage Vth is applied to an unselected element. An emission current of a desired intensity is output only from the element.

[0012]

When FIG. 3 is driven by the above method, a voltage drop actually occurs on the row wiring 4002 as shown in FIG. FIG. 4 is a graph schematically showing a voltage drop generated on the row wiring 4002. The x-axis of the graph is the column direction element number, and the y-axis is the amount of voltage drop. The amount of voltage drop on the y-axis is shown in arbitrary units because it varies depending on the drive voltage, the element characteristics of the element to be formed, and the electric resistance of the wiring of the electron source.

Referring to FIG. 4, it can be seen that the larger the element number in the column direction, that is, the farther from the terminal of the row wiring 4002 the element end, the larger the amount of voltage drop. There is a problem that the amount of electron emission from each element 4001 varies due to the difference in the magnitude of the voltage drop on the row direction wiring. In particular, when the electron source is applied to an image display device, there is a possibility that brightness variations may occur in a displayed image.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and makes it difficult for the amount of electrons emitted from each electronic element to vary due to the effect of a voltage drop during driving, and to simplify the configuration of a driving circuit. It is an object of the present invention to provide an electron source adjusting method and a manufacturing method thereof, an image forming apparatus, an adjusting method and a manufacturing method thereof, and an electron source adjusting apparatus and method, and a storage medium which enable the adjustment.

[0015]

In order to solve this problem, for example, a method for adjusting an electron source according to the present invention has the following arrangement. That is, a method for adjusting an electron source in which a plurality of electron-emitting devices are connected by wiring, comprising a step of adjusting characteristics of at least a part of the electron-emitting devices among the plurality of electron-emitting devices. The characteristics are adjusted by adjusting the characteristics of the plurality of electron-emitting devices so as to suppress a difference in emission current from each electron-emitting device due to a difference in driving conditions of each electron-emitting device that occurs when the electron source is actually driven. Make it different.

According to a preferred embodiment of the present invention,
A method for adjusting the characteristics of an electron source in which a plurality of surface conduction electron-emitting devices are electrically connected by wiring and arranged on a substrate, wherein: 1) the plurality of surface conduction electron-emitting devices are arranged based on a voltage drop generated in the wiring when the electron source is driven. Setting a target value of the characteristic adjustment amount for each of the surface conduction electron-emitting devices; and 2) shifting the characteristics of the plurality of surface conduction electron-emitting devices according to the target value by applying a characteristic shift voltage. Is provided.

[0017]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

[First Embodiment] An example in which the electron source in the embodiment is a multi-electron beam source and applied to an image display device will be described.

First, the configuration and manufacturing method of a display panel of an image display device to which the present embodiment is applied will be described.

<Structure of Display Panel and Manufacturing Method> FIG. 5 is a perspective view of the display panel of the image display device according to the embodiment, in which a part of the panel is cut away to show the internal structure.

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

The rear plate 1005 has a substrate 1001
Are fixed, but n × m surface conduction electron-emitting devices 1002 are formed on the substrate. n and m are appropriately set according to the target number of display pixels. In the present embodiment, n = 3000 and m = 1024. 1001
The portion constituted by the elements 1004 to 1004 is called a multi-electron beam source.

FIG. 6 is a plan view of a multi-electron beam source. The surface conduction type emission device 1002 is provided on the substrate.
These elements are wired in a simple matrix by row-direction wiring electrodes 1003 and column-direction wiring electrodes 1004. An insulating layer (not shown) is formed between the row-directional wiring electrodes 1003 and the column-directional wiring electrodes 1004 where they intersect, so that electrical insulation is maintained.

The multi-electron source having such a structure is as follows.
After a row-direction wiring electrode 1003, a column-direction wiring electrode 1004, an interelectrode insulating layer, an element electrode and a conductive thin film are formed on a substrate in advance, each element is connected to the element via the row-direction wiring electrode 1003 and the column-direction wiring electrode 1004. An electron emission portion was formed in the conductive thin film portion by supplying current and performing a current forming process and a current activation process.

On the lower surface of the face plate 1007, a fluorescent film 1008 is formed. Since the present embodiment is a color display device, a CRT is
The phosphors of three primary colors of red, green, and blue used in the field are separately applied. Phosphors of each color are separately applied in stripes as shown in FIG. 7, and black conductors 1010 are provided between the stripes of the phosphors. Black conductor 10
The purpose of providing 10 is to prevent the display color from being shifted even if the electron beam irradiation position is slightly shifted,
The purpose is to prevent reflection of external light to prevent a decrease in display contrast, and to prevent charge-up of a fluorescent film by an electron beam. Although graphite is used as a main component for the black conductor 1010, any other material may be used as long as it is suitable for the above purpose. The method of applying the three primary color phosphors is not limited to the stripe-shaped arrangement shown in FIG. 7, but may be a delta arrangement or another arrangement.

On the surface on the rear plate side of the fluorescent film 1008, a metal back 1009 known in the field of CRT is provided. The purpose of providing the metal back 1009 is to improve the light utilization rate by mirror-reflecting a part of light emitted from the fluorescent film 1008, to protect the fluorescent film 1008 from negative ion collision, and to apply an electron beam acceleration voltage. The purpose of this is to make the phosphor film 1008 act as a conductive path for the excited electrons. Metal back 10
09 is to attach the fluorescent film 1008 to the face plate substrate 100.
7, the surface of the fluorescent film was smoothed, and Al was formed thereon by vacuum evaporation.

Dx1 to Dxm and Dy1 in FIG.
Dyn and Hv are electric connection terminals of an airtight structure provided for electrically connecting the display panel to an electric circuit (not shown). Dx1 to Dxm are the row direction wirings 1003 of the electron source, and Dy1 to Dyn are the column direction wirings 1 of the electron source.
004 and Hv are the metal back 10 of the face plate.
09 is electrically connected.

In order to evacuate the inside of the hermetic container, after assembling the hermetic container, an exhaust pipe (not shown) and a vacuum pump are connected, and the inside of the hermetic container is evacuated to a degree of vacuum of about 1e-6 [Pa]. I do. 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 about 1e-6 [Pa] due to the adsorbing action of the getter film. The degree of vacuum is maintained.

The image display device is manufactured as described above. Next, an example in which the electron emission characteristic adjusting method according to the embodiment is applied will be described below.

The applicant of the present application has already proposed a technique relating to a surface conduction electron-emitting device. Among these, there are proposals utilizing the memory effect of the surface conduction electron-emitting device. The memory effect of the emission element means that when a voltage that has not been experienced in the past is applied, the threshold value Vth in FIG. 2 shifts to a higher direction, and as a result, the emission current curve in FIG. It shifts to. In the present embodiment, such a property is used.

To briefly explain the characteristic adjustment in the embodiment, the characteristic of an element having a relatively small voltage drop during driving is shifted in a direction in which the amount of emitted electrons at the driving voltage becomes relatively small. If this is applied to each emission element in the row and adjustment is performed for all elements, an element having a relatively large voltage drop emits more electrons at the drive voltage and a relatively large voltage drop. In the case of a small device, adjustment can be made in such a direction that emission electrons at a drive voltage are relatively reduced.
That is, by appropriately adjusting the shift amount of the characteristic according to the magnitude of the voltage drop, the magnitude of the emission current from each element is adjusted to be substantially constant even if the drive voltage varies due to the voltage drop.

Hereinafter, the method will be specifically described with reference to the flowchart of FIG.

First, in step S1 of FIG. 8, a voltage drop generated in the row wiring when the image display device is driven is calculated. Assuming that Vdrop (y) is the voltage drop generated at the y-th element on the row direction wiring (the element closest to the electric connection terminal is the first element), an approximate value can be calculated by the following equation.

Vdrop (y) {Rx × i × If (Vdrv) × (ni)} (Expression 1) Here, Σ is the sum of products for i = 1 to i = y. Symbols are: Rx: resistance value of one section between elements of row direction wiring If (V): element current at voltage V Vdrv: drive voltage for image display n: number of elements in column direction side

The contents displayed by the image display device,
The driving voltage Vdrv for each element may change depending on the driving method (pulse width modulation, pulse height modulation, etc.). In such a case, the average value of the drive voltage of each element may be used for the calculation. In addition, Vdrop once calculated by Equation 1
(Y) calculating the effective drive voltage Vdrv-Vdrop (y), substituting the value into Equation 1, and recalculating Vdrop (y), thereby improving the accuracy of Vdrop (y). Is also possible. In fact, sufficient accuracy could be obtained without repeating the calculation (convergence calculation).

It is necessary to measure and obtain data of Rx and If (V) in advance.

Next, in step S2, an amount by which the characteristic is shifted by each element (the shifted value is also referred to as a target value) is set based on the previously calculated voltage drop based on Vdrop (y). In the present embodiment, the emission current from each element at the effective drive voltage (Vdrv-Vdrop (y)) is adjusted to the value Iedest by shifting the characteristics according to the set target value. In the present embodiment, the current value emitted from the element Dn farthest from the terminal of the row-direction wiring and having the largest voltage drop at the effective drive voltage (Vdrv-Vdrop (n)) is used as the value of Iedest. In the present embodiment, in order to shift the characteristic in a direction in which electrons are hardly emitted, the value of the element Dn that minimizes the emission current in the electron source is used as the value of Iedest. That is, the emission current of the smallest element was adjusted (the smallest element was not adjusted). This makes it possible to obtain substantially uniform luminance while suppressing a decrease in luminance.

A method for setting the target value will be described with reference to FIG. FIG. 9 is a graph of the element characteristics of the y-th element Dy on a certain row direction wiring. Iedrv (y) is the current emitted by the element Dy at the effective drive voltage (Vdrv-Vdrop (y)). Target value Ieshift of element Dy
(Y) is set as a value obtained by subtracting the value Iedest from Iedrvb (y). Such a target value is set, and the element characteristic of the element Dy is changed according to the target value as shown in FIG.
By shifting from (v) to Ie ′ (v), the emission current at the effective drive voltage can be set to Iedest.

Since Iedrv (y) monotonically increases with respect to the effective drive voltage, the target value is set to be larger in an element having a smaller voltage drop Vdrop (y), that is, an element having a larger effective drive voltage. In summary, the target value Ieshift (y) can be expressed by the following equation.

Ieshift (y) = Ie (Vdrv−Vdrop (y)) − Ie (Vdrv−Vdrop (n)) (Equation 2) In step S3, the target value Ie set in step S2.
The element characteristics are adjusted according to shift (y) (y = 1 to y = n).

The inventors have found a correlation in which the characteristic shift amount increases as the characteristic shift voltage increases. FIG. 10 is a graph schematically showing the correlation between the magnitude of the characteristic shift voltage Vshift and the shift amount Shift (Vshift) of the emission current. The X-axis of the graph indicates the voltage value of the shift voltage applied to the element, and the Y-axis indicates the shift amount of the emission current. Note that the shift value of the shift voltage and the voltage value of the shift voltage are shown in arbitrary units because when the material or shape of the element is changed, the shift greatly changes. From the graph, it can be seen that the characteristic shift starts to occur from the voltage Vsth, and monotonically increases with the voltage value, and the shift amount increases.

Therefore, the shift voltage value Vshift (y) necessary for shifting the characteristic from the target value Ieshift (y) is shown in FIG.
The characteristic can be shifted by the target value Ieshift (y) by applying the value to the element Dy. Note that the shift voltage Vshift and the shift amount Shi are
Regarding the correlation (curve) of ft (Vshift), it is necessary to acquire an advance as a data table by repeating an experiment in which the shift voltage is variously changed and the shift amount is measured.

The value of the shift voltage value Vshift (y) is determined according to the target value Ieshift (y) described above, and the element Dy is determined.
By applying the step of applying the shift voltage to all the elements of the image display device, even if a voltage drop occurs when the image display device is driven, a substantially uniform emission current Iedest can be obtained from each element.

The driving voltage Vdrv and the shift voltage have the following relationship so that the element characteristics do not change during display driving.

Vdrv <= Vsth <Vshift (y) (Equation 3) Next, an apparatus used in the characteristic adjustment of this embodiment and a method of adjusting the characteristic using the apparatus will be described with reference to FIG. In FIG. 11, reference numeral 406 denotes a control device. In this embodiment, a personal computer (PC) is used as the control device 406.
Is used. The control of various devices and the control of the entire sequence when the characteristic shift voltage is applied are performed by software running on a PC. The configuration inside the control device 406 will be briefly described. 406-1 is a CPU,
It executes an operating system (OS) and other software and controls the entire control device 406. 406-
Reference numeral 2 denotes an interface such as a parallel I / O and the like.
6-1 was used for communication between each device. 406-3 is RAM
(Random access memory), etc.
In response to an instruction from PU 406-1, data is transferred to CPU 4
06-1.

Reference numeral 401 denotes an image display device. The wiring switches 402 and 403 can arbitrarily switch between connecting the extraction terminal of the image display device 401 and the waveform generators 404 and 405 or connecting to the ground. The wiring changers 402 and 403 are configured by switch elements such as relays, and can perform a switching operation by a signal from the control device 406. Waveform generators 404, 405
Is composed of a memory, a DA converter, and the like, and can output an arbitrary waveform pattern transferred from the memory 406-3 of the control device 406 at a desired timing.
407 is an ammeter. The ammeter 407 was inserted in series between the high voltage output terminal Hv of the image display device and the DC high voltage 408. The data of the ammeter 407 is converted into a digital value (A / D conversion) and transferred to the control device 406.

Now, a specific procedure of characteristic adjustment using the apparatus shown in FIG. 11 will be described. First, the controller 406 calculates the voltage drop Vdrop (y) at the element end of each element on the row wiring based on Equation 1. In the present embodiment, the following values are used for each parameter of Expression 1.

RX = 4.2e-3 [Ω] Vdrv = 14 [V] The element current characteristics If (V) are different from the elements prepared in advance under the same conditions as those of the present embodiment by changing the drive voltage variously. The current is acquired as a data table by measuring the current, and the memory 406-
3

Next, the target value Ieshift of the element characteristic adjustment amount
Calculate (y). The control device 406 calculated the value of the voltage drop Vdrop (y) previously obtained by the equation (2).

Next, from the correlation between the target value Ieshift (y) and the voltage value of the element characteristic adjustment amount versus the characteristic shift voltage obtained in advance through experiments, the voltage value Vshift (y) of the characteristic shift voltage to be applied to each element. (In the present embodiment, 14.5 [V] to 1
7.0 [V]) is calculated by the control device 406 and the control device 4
The result was stored in the memory 406-3 of No. 06.

For the characteristic shift voltage, voltage value = Vshift
(Y) [V], pulse width 1 [ms], period 3 [ms],
Were used. In order to monitor the progress of the characteristic adjustment, a pulse width of 500 [u] is applied between the pulse voltages.
s], and a rectangular wave having a voltage value Vmoni = Vdrv−Vdrop (y) is inserted.

The application of the characteristic shift voltage was performed sequentially for each element. Here, as an example, an example in which a characteristic shift voltage is applied to an element selected by a row direction wiring number x and a column direction wiring number y will be described.

First, the waveform generator 404 was connected to the row wiring x by the wiring switch 402, and the other row wirings were connected to the ground. Similarly, the waveform generator 405 was connected to the column wiring y by the wiring switch 403, and the other column wirings were connected to the ground. After the connection is completed, the voltage value -Vshift (y) / 2 is output from the waveform generator 404.
[V], voltage value + Vshift (y) from waveform generator 405
/ 2 [V] characteristic shift voltage was output. During this time, the ammeter 407 indicates the emission current I when the voltage Vmoni is applied.
Emoni is measured and the data is transferred to the controller 406. The control device 406 monitors Iemoni and stops the output of the waveform generators 404 and 405 when the value falls below Iestest.

During the application of the characteristic shift voltage, the inside of the airtight container of the image display device was kept at a degree of vacuum of about 1e-6 [pa]. The output voltage of the DC high-voltage power supply 408 was set to 1.0 [KV].

As described above, the characteristics of each emission element are not made the same, but rather, by adjusting the respective characteristics differently so as to cancel out the voltage drop by taking into account the voltage drop. It is not necessary to add a circuit for correcting an image signal in a drive circuit for displaying an image, or even if it is provided, the size of the circuit can be reduced.

That is, as described above, in the image display device in which the characteristics are adjusted, a high-quality image display which is hardly affected by a voltage drop during display driving can be performed.

<Second Embodiment> In the second embodiment, an example in which the characteristic adjustment method of the present invention is applied to the same image display device as that described in the first embodiment will be described.

In the first embodiment, the shift amount of the characteristic is adjusted by the peak value of the shift voltage. In the second embodiment, the shift amount of the characteristic is adjusted by the application time of the shift voltage. This is because, as a result of intensive studies, the inventors have found that there is a correlation between the application time of the shift voltage and the shift amount of the characteristic.

FIG. 12 shows the characteristic shift amount Shi when a certain characteristic shift voltage having a voltage value Vsth or more is applied.
It is a figure which shows typically the correlation of ft and the application time of a shift voltage. On the X-axis shown, the shift voltage application time is expressed in logarithm,
The characteristic shift amount Shift is set for each axis. As shown in the figure, the characteristic shift amount increases substantially directly in proportion to the logarithm of the application time of the shift voltage.

Hereinafter, the characteristic adjustment method according to the second embodiment will be described with reference to the flowchart of FIG. Note that only the differences between the first embodiment and the method will be described. The formulas and symbols are also the first
The description will be made using the same components as those of the first embodiment.

The method of calculating the voltage drop caused in the row wiring at the time of driving the image display device in step S1 of FIG. 8 is the same as in the first embodiment.

Next, in step S2, the amount by which the characteristics are shifted in each element is set based on the voltage drop calculated in step S1 based on Vdrop (y). This is the same as in the first embodiment.

In step S3, element characteristics are adjusted in accordance with the target value Ieshift (y) (y = 1 to y = n) set in step S2.

As described above, the present inventors have found a correlation in which the characteristic shift amount increases as the application time of the characteristic shift voltage increases. Therefore, the target value Ieshift
From (y), the shift voltage application time T required for shifting the characteristics
The shift (y) is determined by referring to the curve in FIG. 12 (stored in a memory or a hard disk as a table), and applied to the element Dy to set the target value Ieshift (y).
Only the characteristics can be shifted. The correlation (curve) between the shift voltage application time Tshift and the shift amount Shift
Regarding the above, it is necessary to repeat the experiment of measuring the shift amount while changing the shift voltage application time variously, and to obtain a data table in advance.

The step of determining the value of the time Tshift (y) for applying the shift voltage according to the target value Ieshift (y) described above and applying the shift voltage to the element Dy is performed on all the elements of the image display apparatus. Even if a voltage drop occurs when the image display device is driven, a substantially uniform emission current Ie is obtained from each element.
You can get dest.

The device used in the characteristic adjustment of the second embodiment is the same as the device used in the first embodiment.

In the second embodiment, the voltage value of the characteristic shift voltage is 16.0 [V], the pulse width is 1 [ms], and the period is 3
[Ms]. In order to monitor the progress of the characteristic adjustment, a pulse width of 500 [us] and a voltage value Vmoni = Vdrv-Vdrop (y) are applied between the pulse voltages.
Square wave is inserted.

Also in the second embodiment, the control device 40
6 is an emission current Iemoni when Vmoni is applied.
Was monitored and when the value became Iestest or less, the output of the waveform generators 404 and 405 was stopped even when the application time of the characteristic shift voltage was Tshift (y) or less.

In the image display device having the above-described characteristic adjustment, similar to the first embodiment, it is possible to perform high-quality image display which is hardly affected by a voltage drop during display driving. Can be simplified.

Third Embodiment As a result of intensive studies, the inventors have confirmed the following properties of a surface conduction electron-emitting device.

1. There is a strong (close to one-to-one correspondence) correlation between the device current If and the emission current Ie.

2. Due to the application of the characteristic shift voltage, the element current characteristic shifts similarly to the emission current characteristic.

Based on this fact, in the third embodiment, the shift amount of the device current characteristic flowing through the surface conduction electron-emitting device is set as the target value. That is, if the element current is adjusted so as to be constant even if a voltage drop occurs according to the target value (using the property of 2.), then 1. , The emission current can be kept constant.

In the third embodiment, an example will be described in which the same image display device as that used in the first embodiment is subjected to characteristic adjustment. Since the characteristic adjustment method is basically the same as that of the first embodiment, only the differences will be described. Hereinafter, the same formulas and symbols as those in the first embodiment are used for the overlapping formulas and symbols.

The method of calculating the voltage drop that occurs in the row wiring at the time of driving the image display device in step S1 of FIG. 8 is the same as in the first embodiment.

Next, in step S2 of FIG. 8, a target value is set for each element based on the voltage drop calculated in advance, based on Vdrop (y). In the third embodiment, the effective drive voltage (Vdrv-
Vdrop (y)), the element current of each element is the value Ifdest
To be aligned. In this embodiment, the value of Ifdest is a current value flowing at the effective drive voltage (Vdrv-Vdrop (n)) to the element Dn farthest from the terminal of the row direction wiring and having the largest voltage drop.

A method for setting the target value will be described with reference to FIG. FIG. 11 is a graph of the element current characteristics of the y-th element Dy on a certain row direction wiring. Ifdrv (y) is an element current flowing through the element Dy at an effective drive voltage (Vdrv-Vdrop (y)). Target value Ifshif of element Dy
t (y) is set as a value obtained by subtracting the value Ifdest from Ifdrv (y). In summary, the target value Ifshift
(Y) can be expressed by the following equation.

Ifshift (y) = If (Vdrv−Vdrop (y)) − If (Vdrv−Vdrop (n)) (Equation 4) By shifting the element current characteristics, the voltage drop Vdrop (y) also changes. . In such a case, If in Equation 1
Subtract Ifshift (y) from (Vdrv) and Vdrop (y)
Is calculated again, and the calculation of Expression 4 is repeatedly performed, so that the target value can be set to a more appropriate value. In the third embodiment, it has been confirmed that an appropriate target value can be obtained without repeating such calculation (convergence calculation).

In step S3 of FIG. 8, element characteristics are adjusted in accordance with the target value Ifshift (y) (y = 1 to y = n) set in step S2.

The inventors have found a correlation between the shift amount of the element current characteristic and the characteristic shift amount that increases as the shift voltage increases and the application time increases as in the emission current characteristic. Therefore, the target value Ifshif
Shift voltage value Vshift required to shift characteristics from t (y)
(Y) is (element current characteristic shift amount) vs. (shift voltage value)
It is determined by referring to the correlation, and the characteristic can be shifted by the target value Ifshift (y) by applying it to the element Dy. In the third embodiment, the shift amount of the characteristic is adjusted by the voltage value of the shift voltage. However, the shift amount may be adjusted by the application time of the shift voltage as in the second embodiment.

The value of the shift voltage Vshift (y) is determined according to the target value Ifshift (y) described above, and the element Dy is determined.
By applying a step of applying a shift voltage to all the elements of the image display device, even if a voltage drop occurs when the image display device is driven, a substantially uniform element current Ifdest can flow through each element. That is, a substantially uniform emission current can be output from each element during driving.

Next, an apparatus used in the characteristic adjustment of the third embodiment and a method of adjusting the characteristic using the apparatus will be described with reference to FIG. Since the apparatus and method have basically the same configuration as the apparatus (FIG. 11) used in the first embodiment, only different parts will be described. In FIG. 14, the same parts as those in FIG. 11 have the same numbers.

In FIG. 11, reference numeral 707 denotes an ammeter.
The ammeter 707 includes a waveform generator 404 and a wiring switch 402.
And inserted in series. The data of the ammeter 707 is converted into a digital value and transferred to the control device 406.

As in the first embodiment, the characteristic shift voltage has a voltage value = Vshift (y) [V] and a pulse width of 1 [m].
s] and a rectangular pulse having a period of 3 [ms]. In order to monitor the progress of the characteristic adjustment, a pulse width of 500 [us] and a voltage value Vmoni = Vdrv−
As in the first embodiment, a rectangular wave of Vdrop (y) is inserted.

While the shift voltage is being applied, the control device 40
6 monitors the current Ifmoni when Vmoni is applied, and stops the output of the waveform generators 404 and 405 when the element current becomes equal to or less than Ifdest.

As described above, in the third embodiment, the element current is used as the target value for the characteristic adjustment. However, similar to the case where the emission current is used as the target value, high quality which is hardly affected by a voltage drop during display driving. Image display could be performed.

<Fourth Embodiment> An example in which the fourth embodiment is applied to the same image display device as the first embodiment will be described. In the fourth embodiment, the amount of electrons emitted from each surface conduction electron-emitting device during driving is relatively large in the element near the center of the row-directional wiring, and relatively large in the element near the end of the row-directional wiring. The characteristic is adjusted so as to reduce the number.
That is, a gradation-like luminance distribution from light to dark is generated from the center to the periphery of the image display device.

When such a characteristic adjustment is performed, the luminance distribution at the time of displaying an image tends to resemble a CRT (CRT) generally used in a television, and gives a sense of visual discomfort to an observer who regularly uses the CRT. There is an effect that becomes difficult.
Further, it is possible to reduce the amount of electrons emitted from the elements of the image display device to an average without giving a sense of discomfort to the observer, that is, to reduce the power consumption of the image display device.

Hereinafter, the method will be described only for parts different from the first embodiment. Hereinafter, the formulas, symbols, figures, and the like regarding the common parts are the same as those in the first embodiment.

The method of calculating the voltage drop in step S1 of FIG. 8 is the same as in the first embodiment.

Next, in step S2, a target value is set based on Vdrop (y) calculated in step S1. In the first embodiment, the emission current from each element at the effective drive voltage is set to be equal to the value of Iedest. In the fourth embodiment, the emission current distribution Ieprofile in which the emission current at the effective drive voltage is relatively large in the element near the center of the row direction wiring and relatively small in the element near the end of the row direction wiring.
The target value Ishift (y) is set to have (y).
In this embodiment, the emission current distribution Ieprofile (y) is set by a quadratic curve such as the following equation. Ieprofile
(Y) is the emission current value emitted by the y-th element Dy on the row direction wiring.

Ieprofile (y) = − a (yn−2 / 2) ^ 2 + Ie (Vdrv−Vdrop (n / 2)) (Equation 5) a: Coefficient Ieprofile (y) is graphed as shown in FIG. With the center in the row direction wiring as a peak, the curve becomes an upwardly convex curve with a smaller value toward the periphery. In the fourth embodiment, the distribution Ieprofile (y) is a quadratic curve with respect to y as an example. However, other distribution shapes may be used. It is necessary to appropriately change the coefficient a each time the element production conditions are changed to change the amount of electron emission, or depending on the degree of distribution adjustment.

In the fourth embodiment, the target value Ieshift (y) is expressed by the following equation.

Ieshift (y) = Ie (Vdrv−Vdrop (y)) − Iprofile (y) (Equation 6) If the element characteristics are shifted according to the target value set as described above, the emission current at the effective driving voltage is obtained. The distribution IEprof
ile (y).

The method for shifting the characteristics in step S3 of FIG. 8 and the device for shifting the characteristics are the same as in the first embodiment.

In the image display device having the characteristics adjusted as described above, a high-quality image display that is hardly affected by a voltage drop during display driving can be performed. Further, it was possible to achieve an image display in which an observer who regularly uses a CRT does not easily give a sense of incongruity visually, and a reduction in power consumption of the image display device.

Note that a general-purpose information processing device such as a personal computer is used as the device for controlling the adjustment in the first to fourth embodiments, and the adjustment procedure is realized by a program. Therefore, although it is necessary for the present invention to include the specific hardware shown in FIG. 11 and the like, it is obvious that the above embodiments can be realized by installing a program in the information processing apparatus. That is, in the present invention, the program code itself realizes the functions of the above-described embodiments, and a storage medium storing the program code constitutes the present invention. When the computer executes the readout program codes, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instructions of the program codes. It goes without saying that a case where some or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing is also included.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer, the program code is read based on the instruction of the program code. , The CPU provided in the function expansion card or the function expansion unit performs part or all of the actual processing,
It goes without saying that a case where the function of the above-described embodiment is realized by the processing is also included.

When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to the above-described flowchart shown in FIG. Various types of storage media such as a floppy (registered trademark) disk, CDROM, and MO are conceivable.

[0100]

As described above, according to the present invention, it is possible to reduce the variation in the amount of electron emission from each electronic element due to the influence of the voltage drop during driving and to simplify the configuration of the driving circuit. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a surface conduction electron-emitting device.

FIG. 2 is a diagram illustrating an example of device characteristics of a surface conduction electron-emitting device.

FIG. 3 is a diagram illustrating a wiring method of a multi-beam electron source.

FIG. 4 is a diagram illustrating a voltage drop generated during driving by a multi-electron beam source.

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

FIG. 6 is a plan view of a substrate of the multi-electron beam source according to the embodiment.

FIG. 7 is a plan view illustrating a phosphor array of a face plate of the display panel.

FIG. 8 is a flowchart illustrating a procedure of a characteristic adjustment method according to the embodiment.

FIG. 9 is a diagram illustrating a target value setting method according to the first embodiment.

FIG. 10 is a diagram illustrating a correlation between a shift voltage value and a shift amount of an electron emission characteristic.

FIG. 11 is a diagram illustrating a connection relationship between a characteristic adjustment device and a display panel used in the first embodiment.

FIG. 12 is a diagram showing a correlation between a shift voltage application time and an electron emission characteristic shift amount.

FIG. 13 is a diagram illustrating a target value setting method according to a third embodiment.

FIG. 14 is a diagram illustrating a connection relationship between a characteristic adjustment device and a display panel according to a third embodiment.

FIG. 15 is a diagram illustrating an electron emission distribution in a fourth embodiment.

Claims (30)

[Claims] 1. A method of adjusting an electron source in which a plurality of electron-emitting devices are connected by wiring, comprising a step of adjusting characteristics of at least a part of the plurality of electron-emitting devices. The adjustment of the characteristics is performed by controlling the plurality of electron-emitting devices so as to suppress a difference in emission current from each electron-emitting device due to a difference in driving conditions of each electron-emitting device caused when the electron source is actually driven. Electron source adjustment method that makes the characteristics of the electron source different. 2. A method for adjusting an electron source in which a plurality of electron-emitting devices are connected by wiring, comprising a step of adjusting characteristics of at least a part of the plurality of electron-emitting devices. When the electron source is actually driven, a difference occurs in the driving conditions of the respective electron-emitting devices, and the adjustment of the characteristics is performed by adjusting the driving conditions of the respective electron-emitting devices given the different driving conditions. A method for adjusting an electron source, wherein the characteristics of the plurality of electron-emitting devices are varied so that the emission current has a desired value. 3. The electron source according to claim 1, wherein the characteristic of the electron-emitting device is a relationship between a value of an emission current and a value of a voltage applied to the electron-emitting device. Adjustment method. 4. The adjustment of characteristics of the electron-emitting device is performed by applying a voltage to the electron-emitting device.
4. The method for adjusting an electron source according to any one of claims 3 to 3. 5. The method according to claim 4, wherein the degree of adjustment of the characteristics of the electron-emitting device is controlled by the magnitude of a voltage applied to the electron-emitting device. 6. The method according to claim 5, wherein the degree of adjustment of the characteristics of the electron-emitting device is controlled by the application time of a voltage applied to the electron-emitting device. 7. A voltage applied to the electron-emitting device for adjusting the characteristic is higher than a voltage applied to the electron-emitting device during actual driving. The method for adjusting an electron source according to any one of claims 4 to 6. 8. In the characteristic adjusting step, a voltage equal to or higher than a voltage applied to each of the plurality of electron-emitting devices at the time of actual driving is applied to each of the plurality of electron-emitting devices. Item 8. The method for adjusting an electron source according to any one of Items 1 to 7. 9. The method according to claim 1, further comprising a step of setting a target value of the characteristic adjustment amount before the step of performing the characteristic adjustment.
The method for adjusting an electron source according to claim 1. 10. The method according to claim 1, wherein the step of adjusting the characteristics is performed while monitoring the characteristics of the electron-emitting device. 11. The method according to claim 1, wherein the step of adjusting the characteristics is performed after a gap for applying a voltage for electron emission is formed in the electron-emitting device. Adjustment method of the electron source described in the paragraph. 12. The gap is located between two conductive members facing the gap, and at least one of the two conductive members forming the gap has carbon or a carbon compound as a main component. The method for adjusting an electron source according to claim 11, wherein the electron source is a film. 13. The electronic device according to claim 1, wherein the step of adjusting the characteristics is performed in an atmosphere in which a partial pressure of an organic gas is 1.0 × 10 −6 Pa or less. How to adjust the source. 14. A method of adjusting an electron beam in which a plurality of electron-emitting devices are connected to a common first wiring and each of the plurality of electron-emitting devices is connected to a separate second wiring. A voltage application step of applying a voltage to at least a part of the electron-emitting devices,
The magnitude of the voltage applied in the voltage applying step is:
At the time of actual driving of the electron source, a predetermined first potential is applied to the first wiring, and a second potential that is equal to each of the second wirings is applied to each of the electron-emitting devices. The voltage applied by the first wiring and the second wiring is predicted, and the predicted voltage is higher for the electron-emitting device than for the electron-emitting device whose predicted voltage is relatively lower. The method for adjusting an electron source, wherein the setting is also made large. 15. A method for adjusting an electron source, comprising connecting a plurality of electron-emitting devices to a common first wiring and connecting each of the plurality of electron-emitting devices to a separate second wiring. A voltage application step of applying a voltage to at least a part of the electron-emitting devices,
The application time of the voltage to be applied in the voltage applying step is such that, when the electron source is actually driven, a predetermined first potential is applied to the first wiring and the potential is equal to each of the second wirings. When two potentials are applied, a voltage applied to each of the electron-emitting devices by the first wiring and the second wiring is predicted, and for the electron-emitting device having the larger predicted voltage, the predicted voltage is calculated. Wherein the applied voltage is set longer than that for the electron-emitting device. 16. An adjusting method of an electron source, wherein a plurality of electron-emitting devices are connected to a common first wiring and each of the plurality of electron-emitting devices is connected to a separate second wiring. A voltage application step of applying a voltage to at least a part of the electron-emitting devices,
The magnitude of the voltage applied in the voltage applying step is:
When the electron source is actually driven, the distance from the potential application unit that applies a potential to the first wiring is shorter for the electron-emitting device than for the electron-emitting device that is relatively long. A method for adjusting an electron source, which is set to be large. 17. A method for adjusting an electron source, wherein a plurality of electron-emitting devices are connected to a common first wiring and each of the plurality of electron-emitting devices is connected to a separate second wiring. A voltage application step of applying a voltage to at least a part of the electron-emitting devices,
The application time of the voltage applied in the voltage application step is, for the electron-emitting device having a short distance from a potential application unit that applies a potential to the first wiring when the electron source is actually driven, A method for adjusting an electron source, wherein the distance is set longer than that for the electron-emitting device, which is relatively long. 18. The method according to claim 14, wherein the voltage applied in the voltage applying step is higher than a voltage applied when the electron source is actually driven. How to adjust the electron source. 19. The voltage applied in the voltage applying step is applied by applying different potentials to the first wiring and the second wiring connected to the electron-emitting device to which the voltage is applied. 19. The method for adjusting an electron beam according to any one of claims 18 to 18. 20. The electron source includes a plurality of the first wirings, the plurality of first wirings constitute a matrix wiring together with the plurality of second wirings, and each of the plurality of first wirings Are connected to the plurality of electron-emitting devices,
20. The method according to claim 14, wherein the voltage applying step is performed on a plurality of electron-emitting devices connected to each of the plurality of first wirings. 21. The method according to claim 14, wherein the voltage applying step is performed while monitoring characteristics of the electron-emitting device. 22. The method according to claim 14, wherein the voltage applying step is performed after a gap for applying a voltage for electron emission is formed in the electron-emitting device. How to adjust the electron source. 23. The gap is located between two conductive members facing the gap, and at least one of the two conductive members forming the gap has carbon or a carbon compound as a main component. The method for adjusting an electron source according to claim 22, wherein the electron source is a film. 24. The electron device according to claim 14, wherein the step of applying a voltage is performed in an atmosphere in which a partial pressure of an organic gas is 1.0 × 10 −6 Pa or less. How to adjust the source. 25. An electron source having a plurality of electron-emitting devices, wherein the electron source is adjusted by the method for adjusting an electron source according to claim 1. Description: 26. A method for manufacturing an electron source having a plurality of electron-emitting devices, wherein the method for adjusting an electron source according to claim 1 is performed. 27. A method for adjusting an image forming apparatus, comprising: an electron source having a plurality of electron-emitting devices; and an image forming member that forms an image by using electrons emitted from the electron source. 25. An adjustment method for an image forming apparatus, wherein the adjustment is performed by the electron source adjustment method according to any one of items 1 to 24. 28. An image forming apparatus comprising: an electron source having a plurality of electron-emitting devices; and an image forming member for forming an image by using electrons emitted from the electron source, wherein the image forming apparatus according to claim 27 is provided. An image forming apparatus adjusted by an apparatus adjusting method. 29. A method for manufacturing an image forming apparatus, comprising: an electron source having a plurality of electron-emitting devices; and an image forming member for forming an image by electrons emitted from the electron source, wherein the method comprises the steps of: A method for manufacturing an image forming apparatus, comprising: 30. Connecting a plurality of electron-emitting devices having a characteristic that a characteristic curve of voltage-electron emission shifts when a voltage for adjustment higher than an applied voltage at the time of driving is applied to a plurality of row and column wirings. A storage medium for storing a program code for an adjustment device for adjusting an electron source having a structure arranged in a matrix, wherein the predetermined number of electron emission elements among a plurality of electron emission elements connected to a row of interest wiring. A voltage-electron emission characteristic curve is defined as a target characteristic curve, and when an electron emission element other than the predetermined electron emission element is used as an adjustment target electron emission element, the voltage-electron emission characteristic curve of the adjustment target electron emission element is And storing a program code for applying the adjustment voltage to the target electron-emitting device to be shifted to the characteristic curve of the target voltage-electron emission.憶媒 body.