JP2000066633A - Electron generating device, its driving method, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make correctible with the corrective information of a small amount even when a large number of electron emission elements are provided in correcting in an approximately uniform manner the electron emission characteristic of a plurality of electron emission elements provided in a matrix. SOLUTION: The corrective information on a current drive circuit, the corrective information on the reactive element current in the wiring of the row direction, and the corrective information on the variance in electron emission efficiency are obtained in advance, a target emission current value is obtained using the information, the current running in the selected element is obtained, the current running in the wiring in the row direction to which the selected element belongs is obtained, and the current value to be set to the current drive circuit is obtained (S501-504) by correcting the input/output characteristic for every channel of the current drive circuit. In the step S505, the set current value obtained in the step S504 is stored in a non-volatile memory.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron generator for emitting electrons from a plurality of electron-emitting devices arranged in a matrix, a driving method thereof, and an image forming apparatus having the plurality of electron-emitting devices on a display panel. .

[0002]

2. Description of the Related Art Heretofore, two types of electron-emitting devices, a thermionic electron-emitting device and a cold cathode electron-emitting device, are known. The cold cathode electron emission device includes a field emission type (hereinafter, referred to as “FE type”), a metal / insulating layer / metal type (hereinafter, referred to as “MIM type”), a surface conduction type electron emission device, and the like.

Examples of the surface conduction electron-emitting device include:
M. I. Elinson, Radio Eng. Ele
ctron Pys. , 10, 1290, (1965)
Also, other examples described later are known.

The surface conduction electron-emitting device utilizes a phenomenon in which a thin film having a small area is formed on a substrate and an electric current is caused to flow in parallel with the film surface of the thin film to cause electron emission. Examples of the surface conduction electron-emitting device include a device using an SnO2 thin film by Elinson et al. Dittmer: "Thin Solid
Films ", 9, $ 717 (1972)], In2
O3 / SnO2 thin film [M. Hartwell
and C.I. G. FIG. Fonstad: "IEEE Tran
s. ED Conf. , 519 (1975)], and those based on carbon thin films [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, p. 22, page (1983)] and the like.

[0005] As a typical example of the device configuration of these surface conduction electron-emitting devices, FIG. Hartw
1 shows a plan view of an element by ell et al.

In FIG. 1, reference numeral 3001 denotes a substrate.
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 in FIG. 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 W is
It is set at 0.1 [mm]. In addition, for convenience of illustration, the electron emitting portion 3005 is shown in a rectangular shape at the center of the conductive thin film 3004, but this is a schematic one, and the position and shape of the actual electron emitting portion are faithfully represented. Not necessarily.

M. In the surface conduction electron-emitting device described above, including the device by Hartwell et al.
In general, an electron emission portion is formed by performing an energization process called energization forming on the conductive thin film before electron emission. That is, the energization forming is to form an electron emission portion in a part of the conductive thin film by performing a predetermined energization process on the conductive thin film. For example, in FIG. 32, a predetermined DC voltage or a DC voltage that increases the voltage at a very slow rate of, for example, about 1 V / min is applied to both ends of the conductive thin film 3004, and the conductive thin film 3004 is locally applied. Electron emitting portion 300 that is destroyed, deformed, or altered, and is in an electrically high-resistance state
5 is formed. 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 process, electrons are emitted in the vicinity of the crack.

An example of the FE type is disclosed in, for example, W.S. P. D
yke & W. W. Dolan, "Fie-ld emi
session ", Advance in Electro
nPhysics, 8, 89 (1956), or C.I. A. Spindt, "Physicalpr
operations of thin-film figure
ld emissioncathodes with
molybdenium cones ", J. App.
l. Phys. , 47, 5248 (1976).

As a typical example of the FE type device configuration, FIG. A. 1 shows a cross-sectional view of a device by Spindt et al.

In FIG. 1, reference numeral 3010 denotes a substrate.
Reference numeral 3011 denotes an emitter wiring made of a conductive material. Three
012 is an emitter cone. Reference numeral 3013 denotes an insulating layer. 3014 is a gate electrode. The present device applies an appropriate voltage between the emitter cone 3012 and the gate electrode 3014, thereby forming the emitter cone 301.
Field emission is caused from the front end of the second.

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

As an example of the MIM type, for example,
C. A. Mead, “Operation of tun
nel-emission Devices, J. et al. Ap
pl. Phys. , 32, 646 (1961). A typical example of the MIM type element configuration is shown in a cross-sectional view of FIG.

In FIG. 1, reference numeral 3020 denotes a substrate. Three
Numeral 021 is a lower electrode made of metal. Reference numeral 3022 denotes a thin insulating layer having a thickness of about 100 angstroms. Three
Numeral 023 is an upper electrode made of a metal having a thickness of about 80 to 300 Å. In the MIM type, electrons are emitted from the surface of the upper electrode 3023 by applying an appropriate voltage between the upper electrode 3023 and the lower electrode 3021.

Each of the above-described cold cathode devices can emit electrons at a lower temperature than the hot cathode device, and therefore does not require a heater for heating. Therefore, the structure is simpler than that of the hot cathode device, and a fine device can be manufactured. Further, even if a large number of elements are arranged on the substrate at a high density, problems such as thermal melting of the substrate hardly occur. In addition, unlike the hot cathode device, which operates by heating the heater, the response speed is slow, and the cold cathode device also has the advantage that the response speed is fast. For this reason, research on applying cold cathode devices to various industrial products has been actively conducted.

For example, a surface conduction type electron-emitting device has the advantage that a large number of devices can be formed over a large area since the cold cathode device is particularly simple in structure and easy to manufacture among the above-mentioned cold cathode devices. Therefore, for example, as disclosed in Japanese Patent Application Laid-Open No. 64-31332 by the present applicant, a method of appropriately driving a large number of surface conduction electron-emitting devices arranged on a substrate has been studied.

With respect to the application of the surface conduction electron-emitting device, for example, an image forming device such as an image display device or an image recording device, or a charged beam source has been studied.

Particularly, as an application to an image forming apparatus, for example, as disclosed in US Pat. No. 5,066,883, JP-A-2-257551 or JP-A-4-28137 by the present applicant, An image forming apparatus has been studied in which a surface conduction electron-emitting device is combined with a phosphor that emits light by an electron beam emitted from the device. An image forming apparatus formed by combining such a surface conduction electron-emitting device and a phosphor is expected to have better characteristics than other conventional image forming apparatuses. For example, compared to a liquid crystal display device that has become widespread in recent years, it can be said that it is superior in that it is self-luminous and does not need a so-called backlight, which illuminates the liquid crystal display device, and that it has a wide viewing angle. .

A method of driving a large number of FE type cold cathode devices is disclosed in, for example, US Pat.
04,895. Further, as an example in which the FE type is applied to an image forming apparatus, for example, R.F. The flat panel display reported by Meyer et al. Is known.
[R. Meyer: "Recent Development
ent on Microtips Display
at LETI ", Tech. Digest of 4
th Int. Vacuum Microele-c
tronics Conf. , Nagahama, p
p. 6-9 (1991)] An example in which a number of MIM types are arranged and applied to an image forming apparatus is disclosed in, for example, JP-A-3-55738 by the present applicant.

The present applicant and the inventors have tried cold cathode devices of various materials, manufacturing methods, and structures, including the invention described in the above-mentioned prior art. Furthermore, research is being conducted on a multi-electron beam source in which a large number of cold cathode devices are arranged, and on an image forming apparatus using the multi-electron beam source.

The inventors of the present application have tried a multi-electron beam source by an electric wiring method shown in FIG. 35, for example. That is, it is a multi-electron beam source in which a large number of cold cathode devices are two-dimensionally arranged and these devices are wired in a matrix as shown in the figure.

In the figure, 4001 schematically shows a cold cathode element, 4002 shows a row-direction wiring, 4003
Is a column wiring. Although the row direction wiring 4002 and the column direction wiring 4003 actually have a finite electric resistance, the wiring resistances 4004 and 4005 in FIG.
It is shown as The above-described wiring method is called simple matrix wiring.

Although a 6 × 6 matrix is shown for convenience of illustration, the size of the matrix is not limited to this. For example, in the case of a multi-electron beam source for an image forming apparatus, a desired image is formed. Elements that are sufficient for displaying are arranged and wired.

In a multi-electron beam source in which cold cathode devices are arranged in a simple matrix, a row-direction wiring 4002 and a column-direction wiring 4003 are used to output a desired electron beam.
, An appropriate electric signal is applied. For example, in order to drive an arbitrary one row of the cold cathode elements in the matrix, the selection voltage Vs is applied to the row direction wiring 4002 of the selected row, and the non-selected state is applied to the row direction wiring 4002 of the non-selected row. Selection voltage Vn
Apply s. In synchronization with this, a driving voltage Ve for outputting an electron beam is applied to the column direction wiring 4003. According to this method, the wiring resistances 4004 and 4005
Is ignored, the voltage of Ve-Vs is applied to the cold cathode elements of the selected row, and the voltage of Ve-Vns is applied to the cold cathode elements of the non-selected rows. At this time, if Ve, Vs, and Vns are set to appropriate voltages, an electron beam having a desired intensity is output only from the cold cathode elements in the selected row. At this time, if a different drive voltage Ve is applied to each of the column wirings, an electron beam with a different intensity is output from each of the elements in the selected row. Also, by changing the length of time during which the drive voltage Ve is applied, the length of time during which the electron beam is output can be changed.

As described above, the multi-electron beam source in which the cold cathode devices are arranged in a simple matrix can be applied to various industrial products. For example, if an electric signal corresponding to image information is appropriately applied, the multi-electron beam source can be used for an image forming apparatus. Can be suitably used as an electron source.

However, when a voltage source is connected to a multi-electron beam source (hereinafter, referred to as an electron source) and actually driven by the above-described voltage application method, a voltage drop occurs due to the effect of wiring resistance by simple matrix wiring. For,
There is a problem that the voltage effectively applied to each cold cathode element varies.

The cause of the variation in the applied voltage is as follows.
First, in the simple matrix wiring, the length of the wiring differs for each cold cathode element (that is, the magnitude of the wiring resistance differs for each element).

Second, the magnitude of the voltage drop generated by the wiring resistance 4004 at each portion of the row wiring is not uniform. This occurs because the current branches and flows from the row direction wiring of the selected row to each cold cathode element connected to the selected row, and the magnitude of the current flowing through each of the wiring resistances 4004 is not uniform. Things.

Third, the magnitude of the voltage drop caused by the wiring resistance varies depending on the driving pattern (the image pattern to be displayed in the case of the image forming apparatus). This occurs because the current flowing through the wiring resistance changes depending on the driving pattern.

If the voltage applied to each of the cold cathode devices fluctuates due to the above reasons, the intensity of the electron beam output from each of the cold cathode devices deviates from a desired value. This is inconvenient when applying an electron source in which elements are arranged to a display panel of an image forming apparatus. That is, when applied to an image forming apparatus, for example,
The luminance of the displayed image becomes non-uniform, and the luminance varies depending on the pattern of the displayed image. Further, the variation of the applied voltage in each cold cathode element tends to become more remarkable as the size of the electron sources wired in a simple matrix increases. Therefore, when an image forming apparatus is configured using the above-described electron source, it also becomes a factor that limits the number of pixels, that is, the number of pixels of a cold cathode device (electron-emitting device) that can be disposed in the electron source.

As a result of earnest research in view of such points,
The present inventors have already tried a driving method different from the above-described voltage applying method. This is a voltage source for applying a drive voltage Ve to the column-directional wiring in order to supply a current necessary for outputting a desired electron beam from the cold cathode device when driving the above-mentioned electron source. Instead of connecting a current source.

This method has a strong correlation between a current flowing through the cold cathode device (hereinafter, referred to as device current If) and an amount of electron beams emitted from the cold cathode device (hereinafter, referred to as emission current Ie). This is a method devised as a result of focusing on the relationship, in which the magnitude of the emission current Ie is controlled by controlling the magnitude of the element current If. That is, the magnitude of the device current If necessary to obtain the desired emission current Ie is determined with reference to the (device current If) versus (emission current Ie) characteristics of the cold cathode device, and the determined device current If is determined. Is supplied from a current source connected to the column wiring. According to this method, even if a voltage drop occurs in the wiring resistance, the method is less susceptible to the voltage drop than the method of driving by connecting the voltage source described above. A great effect is observed in reducing the

[0032]

However, there are the following problems. That is, (1) (element current If) versus (emission current I) of each cold cathode element
e) Variation in characteristics: When an electron source is composed of a plurality of cold cathode elements, particularly when applied to an image forming apparatus, the number of elements included in the electron source is reduced from tens of thousands to several millions. Become. Therefore, it is very difficult to manufacture all the cold cathode devices of the electron source so that the electron emission characteristics are substantially the same. Therefore, even if a current of the same magnitude can be applied to these cold cathode devices, the amount of electron beams actually emitted from those devices varies. Therefore, when an image forming apparatus is manufactured by using an electron source provided with such a cold cathode element having a variation in electron emission characteristics as a display panel, the emission luminance of the display panel varies. I will.

(2) Dispersion of current flowing to elements other than the selected element: In an electron source (supposed to have m × n cold cathode elements) as shown in FIG. (Hereinafter, this will be referred to as an element (M, N).) Consider a case in which an electron beam is emitted only from the element (M, N). In this case, the selection voltage Vs is applied to the row wiring M, and the element current If flows through the column wiring N. Then, the non-selection voltage Vns is applied to the row direction wirings 1 to m (excluding M) other than the row direction wiring M. In addition, column direction wirings 1 to n other than the column direction wiring N
(Except for N), no current flows. At this time,
The (m × n) elements on the electron source can be classified into the following three types. A: Element in selected state (element (M, N)): Only one selected element (M, N) is supplied with a selection voltage-
Vs and the inflow current from the column direction wiring, the element (M,
A drive voltage defined by the electron emission characteristics of N) is applied.

B: Element in the half-selected state: The element in the half-selected state is an element other than the element (M, N) wired in the same row as the element (M, N), and an element (M, N). The sum (m + n−) of the elements other than the elements (M, N) wired in the same
2) elements. At this time, a selection voltage −Vs from the row direction wiring is applied to elements other than the elements (M, N) wired in the same row as the elements (M, N). In addition, for elements other than the element (M, N) wired in the same column as the element (M, N), the element (M) is driven by a current flowing from the column-directional wiring to drive the element (M, N). , N) are applied.

C: Unselected state element: The unselected state element is different from the element (M, N) in the row and column direction wiring (mx
(n−m−n + 1) elements. No voltage is applied to the element in this state.

In the above three types of cold cathode devices, the device current of each device changes non-linearly with respect to the voltage applied to the device (the details will be described later). Therefore, the element current representing the luminance signal flows into the “selected element”,
No current should flow into the "half-selected element" and "non-selected element". However, in the “half-selected element”, a certain amount of leakage current actually flows even though only an applied voltage equal to or lower than the threshold is applied. In particular, when the number of elements constituting the electron source exceeds tens of thousands (for example, m = 100, n = 100), the number of “half-selected elements” increases to about 200 or more, and a part of the current representing the luminance signal Flows into the “element in the half-selected state” (hereinafter, the current flowing in other than the “element in the selected state” is referred to as an invalid element current). Therefore, the current value actually flowing through the “selected element” becomes smaller than the current value representing the luminance signal, and as a result, the amount of electron beams (electron beam emission amount) emitted from the “selected element” is reduced. Decrease.
In addition, since the reactive element current may be different for each wiring, even if a luminance signal of the same magnitude is sent to a plurality of cold cathode elements, the amount of electron beams emitted from those elements must not be uniform. There is.

(3) Regarding variation in constant current drive circuit: Consider a case where a drive current is applied from a column wiring to a display panel having a multi-electron beam source as described above, for example, as shown in FIG. At this time, n elements on the same row provided in the multi-electron beam source are 1
If the method of driving simultaneously during the row scanning time (1H) is adopted, n constant current circuits are required to obtain a bright display by increasing the lighting time of the pixels of the display panel. In particular, when such a multi-electron beam source is applied to an image forming apparatus, the number of column direction wirings, that is, the number of constant current circuits is several hundred to several thousand, and the input / output of all these circuits is It is very difficult to make characteristics (output values with respect to command values) substantially the same. For this reason, even if the same command value is given to each constant current circuit from the control circuit of the display panel having the multi-electron beam source, the current actually flowing through each element varies, and as a result, as a display panel, Will cause variations in the light emission luminance.

In order to further suppress the variation in the electron emission characteristics of the cold cathode device, as compared with a method in which a current source is connected to the column-direction wiring of the electron source and drive the same, the inventors of the present invention have proposed a method for driving the electron source. Is provided with a non-volatile memory such as a ROM, and a correction table indicating a predetermined drive rate is stored in the non-volatile memory in advance, and when driving each element, the correction information in the correction table is read out to thereby perform the predetermined operation. The current value flowing for each element is set according to the driving rate.

In such a configuration in which the drive signal is corrected (current value is corrected in the case of current drive), as the display panel of the image forming apparatus has a large screen and / or high definition, a correction table is required. It is necessary to simultaneously realize an increase in the capacity of a memory for storing the correction information in advance and an increase in the reading speed when reading the correction information from the memory.
However, a large-capacity nonvolatile memory cannot satisfy a drive rate in terms of read speed. For this reason, it is conceivable to use a ROM having a high readout speed (hereinafter referred to as a high-speed ROM). However, since such a high-speed ROM generally has a lower degree of integration than a RAM, many high-speed ROMs are required to store all necessary correction information. ROM must be used. For this reason, it becomes a factor of increasing the size of the drive circuit.

The present invention has been made in view of the above-mentioned conventional problems, and is intended to substantially uniformly correct the electron emission characteristics of a plurality of electron-emitting devices provided in a matrix.
It is an object of the present invention to provide an electron generating device that performs correction with a small amount of correction information, a driving method thereof, and an image forming apparatus even when a large number of electron emitting elements are provided.

[0041]

In order to achieve the above object, an electron generator according to the present invention has the following configuration.

That is, a plurality of electron-emitting devices are arranged in a matrix, one terminal of the electron-emitting devices arranged in the same row is connected to the row-directional wiring, and the other of the electron-emitting devices arranged in the same column. Are connected to the column-directional wiring, and among the plurality of electron-emitting devices, in order to drive a selected electron-emitting device, a row-directional wiring and a column-directional wiring including the selected electron-emitting device, An electron generation device including a drive circuit driven based on a drive signal, wherein at least one nonvolatile memory in which first correction information regarding the plurality of electron-emitting devices and / or the drive circuit is stored in advance, A high-speed memory that stores second correction information relating to the plurality of electron-emitting devices and / or the driving circuit; and a first memory that stores the first correction information stored in the nonvolatile memory. And control means for developing as second correction information, wherein the driving circuit drives the selected electron-emitting device based on the second correction information stored in the high-speed memory. .

Also, for example, the high-speed memory can read stored information at least at a speed substantially equal to a driving speed of the driving circuit by the electron generating device, and the control means controls the driving circuit by the driving circuit. Prior to driving, a current value is calculated based on the second correction information read from the high-speed memory, and control is performed such that the drive circuit drives the selected electron-emitting device based on the current value. It is characterized by.

For example, the plurality of types of correction information are:
Preferably, the correction information is correction information indicating a row direction and / or a column direction characteristic of the plurality of electron-emitting devices.

To achieve the above object, the image forming apparatus according to the present invention has the following configuration.

That is, an image forming apparatus having a plurality of image forming elements, wherein a first memory for storing first information;
A second memory that stores information input from the first memory as second information; and a driving unit that supplies a drive signal corrected based on the second information to the image forming element. It is characterized by having.

Further, for example, the first information is the second information.
The information used as the information of is compressed,
The information processing apparatus further includes a developing unit that expands the first information output from the first memory to the second memory.

In order to achieve the above object, a driving method of an electron generating device according to the present invention has the following features.

That is, a plurality of electron-emitting devices are arranged in a matrix, one terminal of the electron-emitting devices arranged in the same row is connected to the row-directional wiring, and the other of the electron-emitting devices arranged in the same column. Are connected to the column-directional wiring, and among the plurality of electron-emitting devices, in order to generate electrons from the selected electron-emitting device, a row-directional wiring and a column-directional wiring including the selected electron-emitting device are used. A driving circuit for driving the electron generating device based on a driving signal, wherein the first correction information on the plurality of electron-emitting devices and / or the driving circuit is stored in one or more nonvolatile memories. Storing, when powering on the electron generator,
The first correction information stored in the non-volatile memory is expanded in the high-speed memory as the second correction information, and the selected electron emission is output based on the second correction information output from the high-speed memory. An element is driven by the driving circuit.

[0050]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electron generating apparatus and an image forming apparatus according to the present invention will be described in detail with reference to the drawings. In the following description, first, a driving circuit of an image forming apparatus as an electron generating apparatus according to the present invention will be described in the first to fourth embodiments, and then a multi-electron beam source ( A structure and a manufacturing method of a display panel including an electron source, and an entire configuration of an image forming apparatus including the driving circuit will be described.

In each of the following embodiments, each pixel in the display panel (FIG. 8) of the image forming apparatus has a one-to-one correspondence with each electron-emitting device of the electron source of the display panel. There are red (R) pixels, blue (B) pixels, and green (G) pixels. Therefore, the plurality of electron-emitting devices provided in the electron source include an electron-emitting device corresponding to a red pixel, an electron-emitting device corresponding to a blue pixel, and an electron-emitting device corresponding to a green pixel. When a current for selecting a desired electron-emitting device is supplied from a driving circuit to these electron-emitting devices, a pixel corresponding to the device can emit light on the display panel.
When selecting a plurality of electron-emitting devices provided in the electron source, a current is supplied to the column wiring or the row wiring connected to each selected element. At this time, if a plurality of electron-emitting devices are selected according to an input image signal, the image panel can display an image without deflecting electrons unlike a general CRT type image forming apparatus. Can be.

[First Embodiment] FIG. 1 shows a first embodiment of the present invention.
FIG. 2 is a block diagram of a drive circuit in the image forming apparatus according to the first embodiment, mainly showing circuits used for normal image forming operations (circuits not shown in FIG. 1 will be described later).

In FIG. 1, reference numeral 101 denotes an image display panel having a plurality of electron-emitting devices, and terminals Dx1 to Dx1.
It is connected to an external electric circuit via xm and Dy1 to Dyn. The image display panel 101 corresponds to a display panel shown in FIG. Also, a high voltage Va is applied to the high voltage terminal Da on the image display panel 101 from the outside by a high voltage power supply, and the high voltage Va accelerates electrons emitted from the electron-emitting devices.

Terminals Dx1 to Dxm are connected to an electron source (not shown) provided in the image display panel 101, ie, M
A scanning signal is applied to sequentially drive the electron-emitting device groups arranged in a matrix of rows N and N columns, one row at a time.

On the other hand, the terminals Dy1 to Dyn have modulation for controlling the amount of electron beams emitted from the electron-emitting devices connected to one row-direction wiring when one of the electron-emitting devices is selected by the scanning signal. A signal is applied.

Next, the scanning circuit 102 will be described.
This circuit includes m switching elements (not shown) inside, and each of these switching elements has a selection voltage Vs
Alternatively, either one of the non-selection voltages Vns can be selected, whereby the scanning circuit 102 and the display panel 101 can be selected.
Can be switched between the terminals Dx1 to Dxm. Here, the selection voltage Vs is an output voltage of a DC voltage source Vx not shown in FIG.
s is set to 0 [V] (ground level). In this embodiment, the output voltage of the DC voltage source Vx is set to a predetermined voltage of 7 [V]. This is because, in the characteristics of the electron-emitting device illustrated in FIG. 28, the threshold voltage at which the electron-emitting device emits electrons is, for example, 8 [V]. Is to make the drive voltage applied by the device smaller than the threshold voltage.

In this embodiment, each of the above-mentioned switching elements is a timing signal generation circuit 104 to be described later.
The circuit operates based on the control signal Tscan output from the controller, but can be easily configured as an actual circuit configuration by combining switching elements such as FETs.

Next, the flow of an externally input image signal will be described.

The composite image signal input to the drive circuit of FIG. 1 is converted by the decoder 103 into three primary colors (RGB).
Luminance signal and horizontal and vertical synchronization signals (HSYNC, VS
YNC).

The timing signal generation circuit 104
Various timing signals are generated in synchronization with the NC and VSYNC signals.

The RGB luminance signal output from the decoder 103 is sampled at an appropriate timing in a sample / hold (S / H) circuit 105, and the sampled signal is held.

The signal held by the S / H circuit 105 is
The serial / parallel (S / P) conversion circuit 106 converts the signals into parallel signals arranged in an order corresponding to the arrangement of the respective phosphors of the image display panel 101.

The pulse width modulation circuit 107 generates a pulse signal having a pulse width corresponding to the size of the parallel signal image signal output from the S / P conversion circuit 106.

The high-speed memory 109 includes the image display panel 10
A semiconductor memory such as a RAM from which stored information can be read at high speed in accordance with the display of each pixel. In the high-speed memory 109, correction information on each electron-emitting device included in the display panel 101 and the current driving circuit 108 is stored in advance as a set value of a current flowing into the column direction wiring. Will be described later). The high-speed memory 109 is accessed by an address signal output from the timing signal generation circuit 104, and, in accordance with the address signal, an electron-emitting device connected to each column-direction wiring (that is, connected to a certain row-direction wiring). The set current values of the individual electron-emitting devices are sequentially read. The read set current values are sequentially input to the current drive circuit 108.

The current driving circuit 108 includes a shift register (not shown) therein, and the shift register stores a set current value of the electron-emitting device connected to each column-directional wiring sequentially input from the high-speed memory 109. Can be held. Thus, the shift register holds the set current value of the electron-emitting device connected to each column wiring. Then, the current drive circuit 108 outputs a current corresponding to the set current value held in the shift register from the pulse width modulation circuit 107 according to a predetermined timing signal output from the timing signal generation circuit 104. The signal is output during the ON period of the pulse signal. The output pulse current is applied to the electron-emitting devices connected to the corresponding column-direction wiring in the display panel 101 via the terminals Dy1 to Dyn.

In the image display panel 101, when a current pulse signal is supplied to the terminals Dy1 to Dyn from the current driving circuit 108, only the electron-emitting devices connected to the row selected by the selection voltage Vs are supplied. Electrons are emitted only for a period corresponding to the current pulse width, and the emitted electrons cause the phosphor to emit light. That is, all the elements on the selected row emit electrons during one horizontal scan (1H) according to the image luminance signal corresponding to the element and the set current value for each element. Therefore, a two-dimensional image is formed by the scanning circuit 102 sequentially scanning the rows from 1 to m.

The above is the outline of the operation at the time of image formation.
Here, when the high-speed memory 109 is a volatile memory, every time the power supply of the electron source driving circuit is turned off, the high-speed memory 10
The correction information stored in 9 is lost. For this reason,
In the present embodiment, the correction information is stored in the nonvolatile memory 110 in advance, and the control circuit 111 stores the correction information stored in the nonvolatile memory 110 in the high-speed memory 109 when the driving circuit is powered on. make a copy. The nonvolatile memory 110 is a semiconductor memory such as a ROM or a flash memory, and does not need to be particularly high-speed. However, depending on the number of electron-emitting devices of the image display panel 101,
It is desirable to have a large capacity memory.

<Acquisition of Correction Information> Next, the high-speed memory 10
The method of obtaining the correction information stored in the No. 9 will be described.
Note that the acquisition of the correction information is performed, for example, in an adjustment process at a factory or at a service base.

First, prior to obtaining the correction information stored in the high-speed memory 109, the correction information on the current drive circuit 108, the correction information on the invalid element current of the column wiring, and the correction information required for obtaining the correction information Element current I
Correction information relating to variations in emission current Ie characteristics (electron emission efficiency) with respect to f is obtained.

I: Acquisition of Correction Information Regarding Current Drive Circuit 108 FIG. 2 is a circuit diagram of FIG. 1 mainly showing a circuit used when acquiring correction information regarding the current drive circuit 108 according to the first embodiment of the present invention. FIG. 2 is a block diagram of a driving circuit, and blocks 103 to 109 shown in the drawing correspond to the driving circuit shown in FIG. Note that the image display panel 101 is omitted in FIG.

The control circuit 111 is connected to an external device 112 such as a computer via an interface not shown in FIG.
Communication can be performed, and the set current value specified from the external device 112 can be written to the high-speed memory 109.

A current detection circuit 120 is provided downstream of the current drive circuit 108. And the current detection circuit 1
20 is followed by a load resistor Rf1 having a known resistance value.
To Rfn are connected.

The current detection circuit 120 has an n-channel current detector. Further, the current detector has a current detection resistor and an amplifier having a resistance value sufficiently smaller than the load resistors Rf1 to Rfn, and a sample / hold that performs sampling according to a timing signal supplied from the timing signal generation circuit 104. It has a circuit. As a result, the current detection circuit 120 detects the n-channel current output from the current drive circuit 108 by individually detecting the potential difference generated between both ends of the n-channel current detection resistor by the current detector. I do. Here, the resistance values of the load resistors Rf1 to Rfn are desirably about several tens of kΩ as values close to the resistance values of the electron-emitting devices.

Next, a procedure for obtaining correction information on the current driving circuit 108 by the circuit shown in FIG. 2 will be described.

(1) First, the external device 112 gives the control circuit 111 a set current value substantially equal to the current value flowing through each electron-emitting device when displaying an image corresponding to the input image signal. As a result, a certain set current value is written to the high-speed memory 109.

(2) Next, an image signal is input to the decoder 103 such that current pulse signals of a predetermined pulse width are simultaneously or sequentially output from all channels of the current drive circuit 108.

(3) Then, the current driving circuit 108 outputs a current pulse signal having a set current value stored in the high-speed memory 109 to each column direction wiring, so that the current pulse signal Synchronously, the current detection circuit 12
With 0, the current flowing from each channel of the current drive circuit 108 is measured.

In measuring the current in the above order,
For a certain set current value, the current drive circuit 10
The current output from each of the channels 8 may be measured, and the characteristic of the output current value with respect to the set current value may be approximated as a straight line passing through the origin for each channel. However, since a certain amount of current may flow even when the set current value is set to 0 [mA], in the present embodiment, a plurality of set current values are measured in the same order as described above, and the measurement is performed. Based on the result obtained, an approximation is made by the following (Equation 1). That is, (set current value) = a × (output current value) + b (Expression 1) Here, a and b are correction information that differs for each channel. The acquired correction information is used in a correction information storage process of FIG. 5 described later.

In the present embodiment, the input / output characteristics of the current driving circuit 108 shown in (Equation 1) are approximated by a linear expression.
It goes without saying that approximation may be performed by a higher-order expression or another function as needed.

As described above, in the present embodiment, the current detector for n channels and the n load resistors are prepared inside the current detection circuit 120. As a smaller number, the output current may be measured for all the channels (the wirings in the column direction) by sequentially switching the channels of the current drive circuit 108 to be measured.

As a result, the correction information indicating “(3) variation in constant current drive circuit” in the above “Problems to be Solved by the Invention” is obtained.

II: Acquisition of Correction Information Regarding Reactive Element Current of Column Direction Wiring FIG. 3 shows, among correction information relating to a plurality of electron-emitting devices wired in a matrix according to the first embodiment of the present invention.
FIG. 4 is a block diagram when acquiring correction information on a reactive element current of a column-directional wiring; FIG.
1 and 103 to 107 correspond to the drive circuit shown in FIG.

In the figure, the pulse signal output from the pulse width modulation circuit 107 is appropriately amplified by the voltage driver 121 to become a voltage pulse signal having the same set voltage value for all columns. This voltage pulse signal is applied to the electron emission elements in the image display panel 101 via the current detection circuit 120 and the terminals Dy1 to Dyn of the display panel 101. On the other hand, the terminals Dx1 to Dxm of the row direction wiring of the display panel 101 are connected to the non-selection voltage Vns.
Is electrically connected to the ground level.

Although the terminals Dx1 to Dxm of the row wiring of the display panel 101 are directly connected to the ground level, all the terminals Dx1 to Dxm are switched to the non-selection voltage Vns by switching using the scanning circuit 102. May be electrically connected.

Next, a description will be given of a procedure for obtaining correction information relating to the reactive element current of the column wiring.

(1) First, a voltage having substantially the same magnitude as a potential generated in each column-direction wiring when an image corresponding to an input image signal is displayed is given to the voltage driver 121 as a set voltage value.

(2) Next, an image signal is input to the decoder 103 such that voltage pulse signals having a predetermined pulse width are simultaneously or sequentially output from all the channels of the voltage driver 121.

(3) The current output from each channel of the voltage driver 121 is measured by the current detection circuit 120 in synchronization with the voltage pulse signal.

When the current is measured in the above order, all the electron-emitting devices connected to the column wiring to which the voltage is applied from the voltage driver 121 apply the non-selection voltage Vns to the row wiring as described above. Is applied, a semi-selected state is established, and an invalid element current of m elements flows through the column direction wiring. At the time of actual image display, since the selection voltage Vs is applied to only one certain row by the scanning circuit 102, an invalid element current due to (m-1) elements flows. Here, considering the case where the image display panel 101 is applied to an image forming apparatus, m is much larger than 100, and the reactive element current due to m elements is the reactive element current due to (m−1) elements. Can be said to be approximately equal to Thus, the reactive element current can be obtained as a constant (correction information) that differs for each column. The acquired correction information on the invalid element current of the column wiring is used in the correction information storing process of FIG. 5 described later.

As a result, the correction information indicating “(2) variation in current flowing through elements other than the selected element” in the above-mentioned “Problems to be Solved by the Invention” is obtained.

III: Emission current Ie with respect to device current If
Acquisition of Correction Information Concerning Variation in Characteristics (Electron Emission Efficiency) FIG. 4 shows, among correction information regarding a plurality of electron-emitting devices wired in a matrix according to the first embodiment of the present invention.
FIG. 4 is a block diagram when acquiring correction information relating to a variation in emission current Ie characteristics (electron emission efficiency) with respect to an element current If; blocks 101 to 107 shown in FIG.
Corresponds to the drive circuit shown in FIG. Further, the current detection circuit 120 and the voltage driver 121 are the same as those described in FIG. However, the image display panel 10
1 is connected to an external high-voltage power supply Va via the Ie monitor circuit 122.

Next, a procedure for obtaining correction information relating to the variation in electron emission efficiency will be described.

(1) First, since there is one high voltage terminal Da for the image display panel 101, when trying to measure Ie for each element by the Ie monitor circuit, one element must be turned on at the same time. Therefore, the decoder 103
At the same time, an image signal is applied such that a voltage pulse signal having a predetermined pulse width is applied only to the electron-emitting devices on one column-direction wiring.

(2) The current flowing from each channel of the voltage driver 121 is measured by the current detection circuit 120 in synchronization with the voltage pulse signal, and the emission current is measured by the element selected by the Ie monitor circuit 122. .

(3) The current measured in this way and
Using the reactive element current measured as described with reference to FIG. 3 and expressing the electron emission efficiency η of each element, η = Ie / If (Equation 2), If = Id −Ileak (Expression 3) Here, If is a current flowing through the selected electron-emitting device. Id is a current flowing into a certain column direction wiring detected by the current detection circuit 120. Ileak
Is the reactive element current of the column wiring connected to the selected element.

According to such a procedure, the electron emission efficiency information can be calculated as a constant different for each element.
The acquired correction information relating to the variation in the electron emission efficiency is used in a process of storing correction information in FIG. 5 described later.

As a result, the above-mentioned [Problems to be Solved by the Invention], "(1) (device current I
f) Variation in (emission current Ie) characteristic "is obtained.

<Storing of Correction Information in Non-Volatile Memory 110> Subsequently, the respective electron sources are driven with substantially uniform electron emission characteristics by using the respective correction information obtained by the above-described procedures I to III. (I.e., correction information for causing each pixel of the display panel to emit light with substantially uniform luminance), a set current value finally stored in the nonvolatile memory 110 is obtained, and the set current value is stored. The processing up to this point will be described with reference to FIG.

FIG. 5 is a flowchart showing a process of storing correction information in the nonvolatile memory 110 according to the first embodiment of the present invention. The software executed by the CPU (not shown) provided in the control circuit 111 is shown in FIG. Show.

In FIG. 10, in step S501, the value of the target emission current Ie is obtained. Here, the target emission current Ie is the same target value for all the electron-emitting devices, which is set to obtain uniform brightness over the entire surface of the image display panel 101.

Next, in step S502, a current flowing through the selected element is obtained. This is the target emission current Ie
Is divided by the electron emission efficiency η of the selected device, which is obtained by the procedure described with reference to FIG.

In step S503, a current flowing through the column wiring to which the selected element belongs is determined. This corresponds to the current flowing through the selected element determined in step S502,
It is obtained by adding the reactive current of the column wiring to which the element belongs, which is obtained by the procedure described with reference to FIG.

If the current value obtained by such a procedure is actually passed through the column wiring, a desired current flows through all the elements, and a substantially uniform emission current can be obtained.

Then, in step S504, the current value to be set in the current drive circuit 108 is obtained by correcting the input / output characteristics of each channel of the current drive circuit 108. That is, the value of the current flowing in the column-direction wiring obtained in step S503 and the correction information a and b, which are the coefficients of the above-described (Equation 1) and are obtained by the method described with reference to FIG. ).

Then, in step S505, the process ends by storing the set current value obtained in step S504 in the nonvolatile memory 110.

Element (M, N) Obtained by the Above Procedure
Is represented by (Equation 4).

Is (M, N) = aN × (Ie / η (M, N) + IleakN) + bN (Equation 4) where (Equation 4), Ie is a target emission current. η (M, N) is an electron emission characteristic specific to the selected element (M, N), that is, a ratio of an emission current emitted from the element to an element current If flowing through the element (electron emission efficiency) ). Ileak is a reactive element current flowing through the column wiring connected to the selected element (M, N). “a” and “b” are coefficients of (Expression 1), which is a linear expression representing input / output characteristics of a drive channel for driving a selected element among a plurality of drive channels of the current drive circuit 108. (Equation 4) representing the set current value Is may be stored in the nonvolatile memory 110.

As described above, when the high-speed memory 109 is a volatile memory, the correction information stored in the high-speed memory 109 disappears every time the power is turned off. The information is backed up, and the control device 111 copies the information from the nonvolatile memory 110 to the high-speed memory 109 when the power is turned on. The non-volatile memory 110 is a semiconductor memory such as a ROM or a flash memory, and does not need to operate at a particularly high speed, but preferably has a large capacity corresponding to the number of elements of the image display panel 101.

As a result, the capacity of the correction table can be increased and the reading speed can be increased at the same time, so that the image display panel can have a larger screen and a higher definition.
Without increasing the size of the device, a uniform emission current value can be obtained for all the elements, and an image display device with no uneven display can be realized.

Therefore, according to the image forming apparatus provided with such a drive circuit, even if the image display panel has a large screen and / or high definition, the emission current characteristics (uniformly uniform) of all the elements of the display panel are obtained. (Light emission characteristics) can be obtained, and display unevenness can be prevented. In addition, the size of the image display panel 101 is increased and the amount of correction information is increased as the definition is increased, and the drive circuit is prevented from being increased in size due to the need for a large number of memories for storing the information. be able to.

[Second Embodiment] Next, a second embodiment of the present invention will be described. The configurations of the electron-emitting device and the display panel in the present embodiment are the same as those described in the first embodiment, and a description thereof will be omitted.

In this embodiment, the nonvolatile memory 1
The correction information stored in the memory 10 is stored in a compressed state, and when the power is turned on, the control circuit 111 decompresses the data, that is, converts the data to the original data size. Expands to 109. here,
Although there is no particular limitation on the compression method, as an example of an electron-emitting device, for example, there are many similar characteristics of a cold cathode device,
The so-called DP is obtained by quantizing the difference from the immediately preceding sample value.
The CM method is effective. Specifically, the correction information of the electron-emitting device adjacent to a certain element of interest is sequentially calculated as a difference from the correction information of the element of interest, and the calculated difference information is stored in the nonvolatile memory 110 as compressed information. do it. At this time, in the correction information to be calculated, a characteristic similar to the row direction or the column direction may appear strongly due to a factor in a process of manufacturing the cold cathode device. It is good to take.

As another method, the nonvolatile memory 1
The correction information stored in 10 is not the individual correction information of all elements, but may be information created by extracting features such as row distribution and column distribution. It is also possible to adopt a method of expanding the data to 109.

As a result, when the same amount of correction information is held, the capacity of the nonvolatile memory 110 can be reduced, and an increase in the size of the drive circuit can be prevented.

[Third Embodiment] FIG. 6 shows a third embodiment of the present invention.
FIG. 3 is a block diagram of a drive circuit in the image forming apparatus according to the first embodiment, mainly showing a circuit used for a normal image forming operation. Configurations of the electron-emitting device and the image display panel in the present embodiment, and 10 in FIG.
The blocks 1 to 112 are the same as those shown in the first embodiment. However, the nonvolatile memory 110 stores several types of correction information. For example, (a)
The correction information of all the electron-emitting devices is stored as (b)
And the correction information from which the column direction characteristics are extracted is stored as (c).

In the present embodiment, the control circuit 111
An instruction is received from the external device 112 as to which correction information stored in the nonvolatile memory 110 is to be expanded in the high-speed memory 109, and the correction information corresponding to the instruction is expanded in the high-speed memory 109. That is, when the correction information of (a) is instructed from the external device 112, the correction information is expanded in the high-speed memory 109, and when the multiplication of the correction information of (b) and (c) is specified, The information according to the instruction is expanded in the high-speed memory 109.

Here, the correction information stored in the non-volatile memory 110 includes correction information for uniformly emitting light over the entire surface of the image display panel 101, as well as making the central portion brighter or a sepia tone. Alternatively, correction information in which a target drive pattern is changed may be used.

According to the present embodiment, the effects explained in the first embodiment are not limited, and
The optimum correction information can be easily selected according to the driving conditions without replacing 0.

[Fourth Embodiment] FIG. 7 shows a fourth embodiment of the present invention.
FIG. 13 is a block diagram of a drive circuit in an image forming apparatus according to the third embodiment, which is substantially the same as the circuit according to the third embodiment, but includes several types of correction information stored in advance in the nonvolatile memory 110; Switch 113 that can set which correction information is to be loaded in high-speed memory 109
Is further provided. This switch 113 is set by the operator.

The control circuit 111 develops the correction information in the high-speed memory 109 according to the correction information set by the switch 113, as in the case where the external device 112 instructs the third embodiment.

According to the present embodiment, it goes without saying that the effects described in the first embodiment can be obtained.
The correction information desired by the operator can be easily selected according to the driving conditions without replacing 0.

[Display Panel] (Configuration and Manufacturing Method of Display Panel) First, the configuration and manufacturing method of a display panel of an image forming apparatus to which the drive circuit according to the present invention is applied will be described with reference to specific examples.

FIG. 8 is a perspective view of a display panel applicable to the present invention, in which a part of the panel is cut away to show the internal structure.

In the figure, 1005 is a rear plate, 1006
Denotes a side wall, and 1007 denotes a face plate. The structure of the rear plate 1005 to the face plate 1007 forms an airtight container for maintaining the inside of the display panel at a vacuum.

In assembling this airtight container,
It is necessary to seal the joints of each member to maintain sufficient strength and airtightness.For example, frit glass is applied to the joints, and the joints are sealed in air or nitrogen atmosphere in Celsius. Sealing is achieved by baking at 400 to 500 degrees for 10 minutes or more. A method for evacuating the inside of the hermetic container to a vacuum will be described later.

The substrate 1001 is provided on the rear plate 1005.
Is fixed, but the cold cathode device 1002 is provided on the substrate.
Are formed in N × M pieces. However, N and M are positive integers of 2 or more, and are appropriately set according to the target number of display pixels. For example, in an image forming apparatus for displaying high-definition television, N = 3000, M = 1
It is desirable to set the number to 000 or more. In this embodiment, N = 3072 and M = 1024.

The N × M cold cathode elements are arranged in a simple matrix by M row-directional wirings 1003 and N column-directional wirings 1004. Hereinafter, the above-described substrate 1001, the cold cathode device 1002, and the M row-direction wirings 10
03 and a portion constituted by the N column direction wirings 1004 are referred to as a multi-electron beam source. The method and structure of the multi-electron beam source will be described later.

In the present embodiment, the substrate 1001 of the multi-electron beam source is fixed to the rear plate 1005 of the airtight container.
If 1 has sufficient strength, the substrate 100 of the multi-electron beam source is used as a rear plate of the hermetic container.
1 itself may be used.

A fluorescent film 1008 is formed on the lower surface of the face plate 1007. Since the image forming apparatus according to the present embodiment is a color image forming apparatus, the fluorescent film 1008 includes red, green,
Phosphors of three primary colors of blue are separately applied. The phosphors of each color are separately applied in a stripe shape as shown in FIG. 9, for example, and a black conductor 1010 is provided between the stripes of the phosphors. The purpose of providing the black conductor 1010 is to prevent the display color from being shifted even if there is a slight shift in the irradiation position of the electron beam, and to prevent the reflection of external light to improve the contrast of the displayed image. It is to prevent the phosphor film from being lowered, and to prevent charge-up of the fluorescent film by the 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.

FIG. 9 shows how to paint the three primary color phosphors.
It is not limited to the striped arrangement shown in
For example, a delta arrangement as shown in FIG. 10 or another arrangement may be used.

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

A metal back 1009 known in the CRT field is provided on the surface of the fluorescent film 1008 on the rear plate side.
Is provided. The purpose of providing the metal back 1009 is
A part of the light emitted from the fluorescent film 1008 is specularly reflected to improve the light utilization rate, or the fluorescent film 1
008, to act as an electrode for applying an electron beam acceleration voltage,
To act as a conductive path for the excited electrons. The metal back 1009 was formed by forming a fluorescent film 1008 on the face plate substrate 1007, smoothing the surface of the fluorescent film, and vacuum-depositing Al thereon. When a fluorescent material for low voltage is used for the fluorescent film 1008, the metal back 1009 is not used.

Although not used in the present embodiment, the gap between the face plate substrate 1007 and the phosphor film 1008 is
For example, a transparent electrode made of ITO may be provided.

Dx1 to Dxm and Dy1 to Dyn and Hv
Is a terminal for electric connection 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 100 of the multi-electron beam source.
3. Dy1 to Dyn are column wirings 10 of the multi-electron beam source.
04 is electrically connected. Hv is electrically connected to the metal back 1009 of the face plate.

To evacuate the interior 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 raised to the power of 10 −7 [T
orr]. Thereafter, the exhaust pipe is sealed, but a getter film (not shown) is formed at a predetermined position in the airtight container immediately before or after the sealing in order to maintain the degree of vacuum in the airtight container. Here, 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 airtight container is 1 × 10−5 due to the adsorbing action of the getter film. Alternatively, the degree of vacuum is maintained at 1.times.10.sup.-7 [Torr].

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

Next, a method of manufacturing the multi-electron beam source used for the display panel shown in FIG. 8 will be described.

The material, shape, and manufacturing method of the cold cathode element are not limited as long as the multi-electron beam source used in the image forming apparatus having the above-described driving circuit is an electron source in which the cold cathode elements are arranged in a simple matrix. Therefore, for example, a cold cathode device such as a surface conduction type emission device, an FE type, or an MIM type can be used.

However, in a situation where an inexpensive image forming apparatus having a large display screen is required, among these cold cathode devices, a surface conduction type emission device is particularly preferable.
That is, in the FE type, the relative position and the shape between the emitter cone and the gate electrode greatly affect the electron emission characteristics, and therefore, extremely high precision manufacturing technology is required. Therefore, it is a disadvantageous factor in achieving an increase in area and a reduction in manufacturing cost. Further, in the MIM type, it is necessary to make the thickness of the insulating layer and the upper electrode thin and uniform, which is also a disadvantageous factor in achieving an increase in area and a reduction in manufacturing cost. That point,
Since the surface conduction electron-emitting device is relatively simple to manufacture,
It is easy to increase the area and reduce the manufacturing cost. In addition, the present inventors have found that among the surface conduction electron-emitting devices, those in which the electron-emitting portion or its peripheral portion is formed of a fine particle film have particularly excellent electron-emitting characteristics and can be easily manufactured. Therefore, it can be said that it is most suitable for use in a multi-electron beam source of a high-brightness, large-screen image forming apparatus. Therefore, in the display panel of this embodiment, a surface conduction electron-emitting device in which the electron-emitting portion or its peripheral portion is formed of a fine particle film is used. Therefore, the basic configuration, manufacturing method and characteristics of a suitable surface conduction electron-emitting device will be described first, and then the structure of a multi-electron beam source in which a large number of devices are arranged in a simple matrix will be described.

(Suitable Device Configuration and Manufacturing Method of Surface Conduction Emission Device) A typical configuration of a surface conduction electron-emitting device in which an electron-emitting portion or its peripheral portion is formed from a fine particle film is a flat type or a vertical type. Types.

(Planar surface conduction electron-emitting device) First, the structure and manufacturing method of a flat surface conduction electron-emitting device will be described.

FIG. 11 is a plan view illustrating the structure of a planar surface conduction electron-emitting device applicable to the present invention. FIG. 12 is a cross-sectional view illustrating a configuration of a planar surface conduction electron-emitting device applicable to the present invention.

11 and 12, 1101 is a substrate, 1102 and 1103 are device electrodes, 1104 is a conductive thin film, 1105 is an electron-emitting portion formed by energization forming, and 1113 is a thin film formed by energization activation. is there.

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

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

The shapes of the device electrodes 1102 and 1103 are appropriately designed according to the application purpose of the electron-emitting device.
In general, the electrode interval L is usually designed by selecting an appropriate value from the range of several hundred angstroms to several hundred micrometers. It is in the range of tens of micrometers. Further, regarding the thickness d of the device electrode,
Usually, an appropriate numerical value is selected from the range of several hundred angstroms to several micrometers.

Further, a fine particle film is used for the portion of the conductive thin film 1104. The fine particle film mentioned here is a film containing many fine particles as a constituent element (including an island-shaped aggregate).
I mean If you examine the microparticle film microscopically, usually
A structure in which the individual particles are spaced apart, a structure in which the particles are adjacent to each other, or a structure in which the particles overlap each other is observed.

The particle size of the fine particles used in the fine particle film is in the range of several Angstroms to several thousand Angstroms, but is more preferably in the range of 10 Angstroms to 200 Angstroms. Further, the thickness of the fine particle film is appropriately set in consideration of various conditions described below. That is, the device electrode 1102
Alternatively, conditions necessary for good electrical connection with 1103, conditions necessary for satisfactorily performing energization forming described later, conditions necessary for setting the electrical resistance of the fine particle film itself to an appropriate value described later, And so on.

More specifically, the distance is set within a range of several Angstroms to several thousand Angstroms, and a preferable range is between 10 Angstroms and 500 Angstroms.

Materials that can be used to form the fine particle film include, for example, Pd, Pt, Ru, Ag, A
u, Ti, In, Cu, Cr, Fe, Zn, Sn, T
a, W, Pb, and other metals, PdO, Sn
Oxides such as O2, In2 O3, PbO, Sb2 O3, etc., HfB2, ZrB2, LaB6, CeB
Borides such as 6, YB4, GdB4, etc .;
Carbides such as iC, ZrC, HfC, TaC, SiC, WC, etc., nitrides such as TiN, ZrN, HfN, etc., semiconductors such as Si, Ge, etc., carbon, etc. And these are appropriately selected from these.

As described above, the conductive thin film 1104 is formed of a fine particle film.
It was set to be included in the range of 10 3 to 10 7 [Ohm / sq].

The conductive thin film 1104 and the device electrode 110
2 and 1103 are desirably electrically connected well, and therefore have a structure in which a part of each overlaps. In the example of FIG. 11 and FIG. 12, the overlapping manner is such that the substrate, the device electrode, and the conductive thin film are stacked in this order from the bottom, but in some cases, the substrate, the conductive thin film, and the device electrode are stacked in that order from the bottom. They may be stacked.

The electron-emitting portion 1105 is a crack-like portion formed in a part of the conductive thin film 1104, and has a higher electrical property than the surrounding conductive thin film. The crack is formed by performing a later-described energization forming process on the conductive thin film 1104. Fine particles having a particle size of several Angstroms to several hundred Angstroms may be arranged in the crack. Since it is difficult to accurately and accurately show the actual position and shape of the electron-emitting portion, they are schematically shown in FIGS.

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

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

Since it is difficult to accurately show the actual position and shape of the thin film 1113, it is schematically shown in FIGS. 11 and 12. Further, in the plan view of FIG. 11, an element in which a part of the thin film 1113 is removed is illustrated.

The basic structure of the preferred element has been described above. In this example, the following element was used.

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

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

Next, a method of manufacturing a suitable flat surface conduction electron-emitting device will be described. 13 to 17 are cross-sectional views for explaining a manufacturing process of a planar surface conduction electron-emitting device applicable to the present invention, and reference numerals of members in each drawing are the same as those in FIGS. 11 and 12. .

1) First, as shown in FIG.
Element electrodes 1102 and 1103 are formed on the substrate 01. Before forming, the substrate 1101 is washed with a detergent,
After sufficiently washing with pure water and an organic solvent, the material for the device electrode is deposited. Here, as a deposition method, for example, a vacuum deposition technique such as an evaporation method or a sputtering method may be used. Thereafter, the deposited electrode material is patterned by using a photolithography / etching technique to form a pair of device electrodes (1102 and 1103) shown in FIG.

2) Next, as shown in FIG. 14, a conductive thin film 1104 is formed. In the formation, first, an organic metal solution is applied to the substrate in the state shown in FIG. 13 and dried, and the dried substrate is heated and baked to form a fine particle film, and then a predetermined film is formed by photolithography and etching. Is patterned. Here, the organometallic solution is a solution of an organometallic compound whose main element is a material of fine particles used for the conductive thin film. Specifically, in this example, Pd was used as a main element. In the present embodiment, the dipping method is used as the coating method, but other methods such as a spinner method and a spray method may be used.

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

3) Next, as shown in FIG. 15, an appropriate voltage is applied between the device electrodes 1102 and 1103 from the forming power supply 1110, and the energization forming process is performed to form the electron emission portion 1105.

Here, the energization forming process is suitable for energizing the conductive thin film 1104 made of a fine particle film, and appropriately breaking, deforming or altering a part thereof to emit electrons. This is the process of changing the structure. A portion of the conductive thin film made of the fine particle film that has been changed to a structure suitable for emitting electrons (that is, the electron emitting portion 110
In 5), an appropriate crack is formed in the thin film.
Incidentally, when compared with before the electron emission portion 1105 is formed,
After the formation, the electric resistance measured between the device electrodes 1102 and 1103 greatly increases.

FIG. 18 shows an example of an appropriate voltage waveform applied from the forming power supply 1110 in order to explain the energization method in more detail. When forming a conductive thin film made of a fine particle film, a pulse-like voltage is preferable. In the case of this embodiment, a triangular wave pulse having a pulse width T1 is continuously generated at a pulse interval T2 as shown in FIG. Was applied. At that time, the peak value Vpf of the triangular wave pulse was sequentially increased. In addition, monitor pulses Pm for monitoring the state of formation of the electron-emitting portion 1105 are inserted between triangular-wave pulses at appropriate intervals, and the current flowing at that time is measured by an ammeter 1111.
Was measured.

In this embodiment, for example, in a vacuum atmosphere of about 10 −5 [torr], for example, the pulse width T1 is 1 [millisecond] and the pulse interval T2 is 10 [milliseconds].
[Milliseconds], and the peak value Vpf is set to 0.1 for each pulse.
The voltage was increased by [V]. Then, each time five triangular waves were applied, the monitor pulse Pm was inserted at a rate of once. The monitor pulse voltage Vpm was set to 0.1 [V] so as not to adversely affect the forming process. The electric resistance between the device electrodes 1102 and 1103 is 1
The current measured by the ammeter 1111 at the stage when the power reaches x10 6 [ohm], that is, when the monitor pulse is applied, is 1 × 10
When the current value became equal to or less than the minus 7th power [A], the energization related to the forming process was terminated.

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

4) Next, as shown in FIG. 16, an appropriate voltage is applied between the element electrodes 1102 and 1103 from the activating power supply 1112, and a current activation processing is performed to improve the electron emission characteristics. I do.

Here, the energization activation process is a process of energizing the electron emitting portion 1105 formed by the energization forming process under appropriate conditions to deposit carbon or a carbon compound in the vicinity thereof. . In FIG. 16, a deposit made of carbon or a carbon compound is schematically shown as a member 1113. In addition, by performing the energization activation process, the emission current at the same applied voltage can be typically increased by 100 times or more compared to before the energization activation process.

Specifically, 10 minus the fourth power to 1
By applying a voltage pulse periodically in a vacuum atmosphere within the range of 0 to the fifth power [torr], carbon or a carbon compound originating from an organic compound existing in the vacuum atmosphere is deposited. The deposit 1113 is any of single crystal graphite, polycrystalline graphite, and amorphous carbon, or a mixture thereof, and has a thickness of 500.
[Angstrom] or less, more preferably 300 [angstrom] or less.

FIG. 19 shows an example of an appropriate voltage waveform applied from the activation power supply 1112 in order to explain the energization method in more detail. In the present embodiment, the energization activation process is performed by periodically applying a rectangular wave of a predetermined voltage.
Specifically, the voltage Vac of the rectangular wave was 14 [V], the pulse width T3 was 1 [millisecond], and the pulse interval T4 was 10 [millisecond]. It should be noted that the above-mentioned energization conditions are preferable conditions for the surface conduction electron-emitting device of the present embodiment, and when the design of the surface conduction electron-emitting device is changed, it is desirable to appropriately change the conditions accordingly.

Reference numeral 1114 shown in FIG. 16 denotes an anode electrode for capturing an emission current Ie emitted from the surface conduction electron-emitting device.
16 are connected. Note that, when the activation process is performed after the substrate 1101 is incorporated in the display panel, the phosphor screen of the display panel is used as the anode electrode 1114. While the voltage is applied from the activation power supply 1112, the emission current Ie is measured by the ammeter 1116 to monitor the progress of the energization activation process, and control the operation of the activation power supply 1112. An example of the emission current Ie measured by the ammeter 1116 is shown in FIG. Referring to FIG.
When the pulse voltage starts to be applied from time to time, the emission current Ie increases with time, but eventually saturates and hardly increases. As described above, when the emission current Ie is substantially saturated, the application of the voltage from the activation power supply 1112 is stopped, and the energization activation process ends.

The above-described energization conditions are preferable conditions for the surface conduction electron-emitting device of the present embodiment. If the design of the surface conduction electron-emitting device is changed, the conditions should be changed accordingly. desirable.

As described above, the plane type surface conduction electron-emitting device shown in FIG. 17 was manufactured.

(Vertical Type Surface Conduction Emission Element) Next, another typical configuration of a surface conduction type emission element in which the electron emission portion or its periphery is formed of a fine particle film, that is, a vertical type surface conduction type emission device. The configuration of the element will be described.

FIG. 21 is a schematic sectional view for explaining the basic structure of a vertical surface conduction electron-emitting device applicable to the present invention.

In the figure, reference numeral 1201 denotes a substrate, 1202 and 120
Reference numeral 3 denotes an element electrode; 1206, a step forming member; 1204, a conductive thin film using a fine particle film; 1205, an electron emitting portion formed by energization forming; and 1213, a thin film formed by energization activation.

The difference between the vertical type and the flat type described above is that one of the element electrodes (1202) is provided on the step forming member 1206, and the conductive thin film 1204 is provided on the side surface of the step forming member 1206. It is in the point of coating. Therefore, the element electrode interval L in the planar type shown in FIGS. 11 and 12 is set as the step height Ls of the step forming member 1206 in the vertical type. In addition, the substrate 1201, the element electrode 1
202 and 1203, conductive thin film 12 using fine particle film
For 04, the materials listed in the description of the planar type can be similarly used. For the step forming member 1206, an electrically insulating material such as SiO2 is used.

Next, a method of manufacturing a vertical surface conduction electron-emitting device will be described.

FIGS. 22 to 27 are cross-sectional views for explaining the steps of manufacturing a vertical surface conduction electron-emitting device applicable to the present invention. The reference numerals of the members in each drawing are the same as those in FIG. .

1) First, as shown in FIG.
The element electrode 1203 is formed over the element 01.

2) Next, as shown in FIG. 23, an insulating layer for forming a step forming member is laminated. The insulating layer may be formed by stacking, for example, SiO2 by sputtering, but other film forming methods such as, for example, vacuum evaporation or printing may be used.

3) Next, as shown in FIG. 24, an element electrode 1202 is formed on the insulating layer.

4) Next, as shown in FIG. 25, a part of the insulating layer is removed by using, for example, an etching method to expose the element electrode 1203.

5) Next, as shown in FIG. 26, a conductive thin film 1204 using a fine particle film is formed. For the formation, as in the case of the flat type described above, a film forming technique such as a coating method may be used.

6) Next, as in the case of the flat type described above, the energization forming process is performed to form an electron emission portion. Specifically, a process similar to the planar energization forming process described with reference to FIG. 15 may be performed.

7) Next, similarly to the case of the above-mentioned flat type, a current activation process is performed to deposit carbon or a carbon compound near the electron emitting portion. Specifically, the same process as the planar energization activation process described with reference to FIG. 16 may be performed.

Through the above steps, a vertical surface conduction electron-emitting device shown in FIG. 27 was manufactured.

(Characteristics of Surface Conduction Emission Element Used in Image Forming Apparatus) Next, characteristics of the element used in the image forming apparatus according to this embodiment will be described.

FIG. 28 is a diagram showing a change in the emission current Ie during the energization activation process applicable to the present invention.
e) vs. (device applied voltage Vf) characteristics and (device current I
f) A typical example of the characteristic versus the (applied voltage Vf) is shown.
Note that the emission current Ie is significantly smaller than the device current If, and it is difficult to show the same current on the same scale. In addition, these characteristics are changed by changing design parameters such as the size and shape of the device. Therefore, the two graphs are shown in arbitrary units.

The element used in the image forming apparatus in this embodiment has the following three characteristics regarding the emission current Ie.

First, a certain voltage (this is referred to as a threshold voltage Vth
When a voltage of the above magnitude is applied to the element, the emission current Ie sharply increases. On the other hand, at a voltage lower than the threshold voltage Vth, the emission current Ie is hardly detected. That is, the non-linear element has a clear threshold voltage Vth with respect to the emission current Ie.

Secondly, since the emission current Ie changes depending on the voltage Vf applied to the element, the emission current Ie varies with the voltage Vf.
The magnitude of e can be controlled.

Third, since the response speed of the current Ie emitted from the element is fast with respect to the voltage Vf applied to the element, the amount of charge of the electrons emitted from the element depends on the length of time during which the voltage Vf is applied. Can control.

Because of the above characteristics, the surface conduction electron-emitting device can be suitably used in an image forming apparatus. For example, in an image forming apparatus provided with a number of elements corresponding to pixels of a display screen, if the first characteristic is used,
Display can be performed by sequentially scanning the display screen.
That is, a voltage equal to or higher than the threshold voltage Vth is appropriately applied to the element being driven, and a voltage lower than the threshold voltage Vth is applied to the element in a non-selected state. By sequentially switching the elements to be driven, the display screen can be sequentially scanned and displayed.

Further, since the emission luminance can be controlled by using the second characteristic or the third characteristic, a gradation display can be performed.

(Structure of a multi-electron beam source in which a large number of elements are arranged in a simple matrix) Next, a structure of a multi-electron beam source in which the above-mentioned surface conduction electron-emitting elements are arranged on a substrate and arranged in a simple matrix will be described.

FIG. 29 is a plan view of a multi-electron beam source applicable to the present invention, and is a plan view of a multi-electron beam source used for the display panel of FIG. On the substrate, FIG.
In addition, a plurality of surface conduction emission devices similar to the devices shown in FIG. 12 are arranged. These elements are wired in a simple matrix by row-directional wiring electrodes 1003 and column-directional 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 the electrodes intersect, so that electrical insulation is maintained.

FIG. 30 is a cross-sectional view of the surface conduction electron-emitting device applicable to the present invention, taken along the line AA ′ of FIG. A multi-electron source having a structure as shown in FIG. 1 has a row-direction wiring electrode 1003, a column-direction wiring electrode 1004, an interelectrode insulating layer (not shown), a device electrode of a surface conduction electron-emitting device, and a conductive material. After the conductive thin film was formed, power was supplied to each element via the row-direction wiring electrodes 1003 and the column-direction wiring electrodes 1004 to perform the energization forming process and the energization activation process.

<Image Forming Apparatus> FIG. 31 is a block diagram showing a configuration example of an image forming apparatus using a display panel driven by a driving circuit according to the present invention. FIG. 1 is a diagram illustrating an example of an image forming apparatus configured to be able to display image information provided from various image information sources such as a television broadcast on a display panel using, for example.

In the figure, reference numeral 2100 denotes a display panel, 2101 denotes a display panel driving circuit corresponding to the driving circuit in each of the above-described embodiments, 2102 denotes a display controller, 2103 denotes a multiplexer, 210
4 is a decoder, 2105 is an input / output interface circuit,
2106 is a CPU, 2107 is an image generation circuit, 2108
2109 and 2110 are image memory interface circuits, 2111 is an image input interface circuit, 211
2 and 2113 are TV signal receiving circuits, and 2114 is an input unit. When the image forming apparatus receives a signal including both video information and audio information such as a television signal, the image forming apparatus naturally reproduces the audio simultaneously with the display of the video. Descriptions of circuits, speakers, and the like relating to reception, separation, reproduction, processing, storage, and the like of audio information that is not directly related to the features are omitted.

The function of each section will be described below along the flow of image signals in the image forming apparatus shown in FIG.

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

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

Also, the image input interface circuit 211
Reference numeral 1 denotes a circuit that captures an image signal supplied from an image input device such as a TV camera or an image reading scanner.
The captured image signal is output to the decoder 2104.

Also, the image memory interface circuit 21
Reference numeral 10 denotes a circuit that captures an image signal stored in a video tape recorder (hereinafter, abbreviated as VTR). The captured image signal is output to a decoder 2104.

The image memory interface circuit 21
Reference numeral 09 denotes a circuit for taking in an image signal stored in the video disk.
4 is output.

The image memory interface circuit 21
A circuit 08 captures an image signal from a device storing still image data, such as a so-called still image disk. The captured still image data is input to the decoder 2104.

The input / output interface circuit 2105
Is a circuit for connecting the image forming apparatus to an external computer, a computer network, or an output device such as a printer. It goes without saying that image data and character / graphic information are input / output. In some cases, control signals and numerical data can be input / output between the CPU 2106 provided in the image forming apparatus and the outside. is there.

[0211] The image generation circuit 2107 includes image data and character / graphic information input from the outside via the input / output interface circuit 2105, or the CPU 2106.
This is a circuit that generates display image data based on image data and character / graphic information output from the display unit. The circuit includes, for example, a rewritable memory for storing image data and character / graphic information, a read-only memory storing an image pattern corresponding to a character code, a processor for performing image processing, and the like. And other circuits necessary for generating an image.

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

The CPU 2106 mainly performs operation control of the image forming apparatus and operations related to generation, selection, and editing of a display image. The CPU 2106 outputs a control signal to the multiplexer 2103, for example, and appropriately selects or combines image signals to be displayed on the display panel. At this time, a control signal is generated for the display panel controller 2102 in accordance with the image signal to be displayed, and the screen display frequency, the scanning method (for example, interlaced or non-interlaced), the number of scanning lines on one screen, The operation of the image forming apparatus is appropriately controlled.

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

The CPU 2106 may, of course, be involved in work for other purposes. For example, it may directly relate to a function of generating and processing information, such as a personal computer or a word processor. Alternatively, as described above, the input / output interface circuit 210
5 to connect to an external computer network,
For example, operations such as numerical calculation may be performed in cooperation with an external device.

The input unit 2114 is connected to the CPU 2106
The user inputs commands, programs, data, and the like. For example, in addition to a keyboard and a mouse, various input devices such as a joystick, a barcode reader, and a voice recognition device can be used.

The decoder 2104 is a circuit for inversely converting various image signals input from the image generation circuit 2107 to the TV signal reception circuit 2113 into three primary color signals or a luminance signal and an I signal and a Q signal. It is preferable that the decoder 2104 has an internal image memory as shown by a dotted line in FIG. This is for handling television signals that require an image memory when performing inverse conversion, such as the MUSE method. Further, the provision of the image memory facilitates display of a still image, or facilitates image processing and editing including image thinning, interpolation, enlargement, reduction, and synthesis in cooperation with the image generation circuit 2107 and the CPU 2106. This is because the advantage of being able to do so is born.

The multiplexer 2103 has a CPU
A display image is appropriately selected based on a control signal input from 2106. That is, the multiplexer 2103
Selects a desired image signal from the inversely converted image signals input from the decoder 2104 and selects a driving circuit 210
Output to 1. In that case, by switching and selecting an image signal within one screen display time, it is possible to divide one screen into a plurality of areas and display different images depending on the areas, as in a so-called multi-screen TV. .

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

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

[0221] As a signal relating to the display panel driving method, a signal for controlling, for example, a screen display frequency and a scanning method (for example, interlace or non-interlace) is output to the drive circuit 2101.

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

The drive circuit 2101 generates a drive signal to be applied to the display panel 2100, and operates based on an image signal input from the multiplexer 2103 and a control signal input from the display panel controller 2102. Things.

The function of each section has been described above. With the configuration illustrated in FIG. 31, in the present image forming apparatus, image information input from various image information sources can be displayed on the display panel 2100. . That is, various image signals including television broadcasting are transmitted to the decoder 2.
After the inverse conversion at 104, the multiplexer 2103
And the selected image signal is input to the drive circuit 2101. On the other hand, the display controller 2102 controls the driving circuit 2 according to an image signal to be displayed.
A control signal for controlling the operation of 101 is generated. The driving circuit 2101 applies a driving signal to the display panel 2100 based on the image signal and the control signal. Accordingly, an image is displayed on display panel 2100. These series of operations are totally controlled by the CPU 2106.

In the present image forming apparatus, the image memory built in the decoder 2104 and the image generation circuit 21
07 and information selected from the information, as well as image information to be displayed, such as enlargement, reduction, rotation, movement, edge enhancement, thinning, interpolation, color conversion, image aspect ratio conversion, etc. Initial image processing, compositing, erasing,
It is also possible to perform image editing such as connection, replacement, and fitting.

Although not particularly described in the description of this embodiment, a dedicated circuit for processing and editing audio information may be provided as in the above-described image processing and image editing.

Therefore, the present image forming apparatus can be used as a television broadcast display device, a video conference terminal device, an image editing device that handles still images and moving images, a computer terminal device,
The functions of office terminal equipment such as a word processor, a game machine, and the like can be provided as a single unit, and the application range is extremely wide for industrial use or consumer use.

FIG. 31 shows only an example of the configuration of an image forming apparatus using a display panel using a surface conduction electron-emitting device as an electron beam source, and the present invention is not limited to this. Needless to say. For example, circuits related to functions that are unnecessary for the purpose of use among the components in FIG. 31 may be omitted. Conversely, additional components may be added depending on the purpose of use. For example, when the present image forming apparatus is applied to a videophone, it is preferable to add a transmission / reception circuit including a television camera, an audio microphone, an illuminator, and a modem to the components.

In the present image forming apparatus, in particular, it is easy to reduce the thickness of the display panel using a surface conduction electron-emitting device as an electron source, so that the depth of the image forming apparatus can be reduced. In addition, since the display panel using the surface conduction electron-emitting device as the electron beam source can easily enlarge the screen, have high brightness, and have excellent viewing angle characteristics, the image forming apparatus has a realistic and powerful image. Can be displayed with good visibility.

In each of the above-described embodiments, the color image forming apparatus in which one electron-emitting device corresponds to one pixel of RGB has been described. However, the present invention is not limited to this. May be applied to an image forming apparatus for an image, a light source for forming an image of an optical printer, and an exposure apparatus for a positive resist or a negative resist.

The electron emitting device constituting the electron source is not limited to a surface conduction type electron emitting device, but may be a general low impedance device having a non-linear voltage V / current I characteristic as shown in FIG. Can also be applied to the element of the above.

Further, in each of the above-described embodiments, the current driving circuit is arranged in the column direction wiring, and the determined current flows in the column direction wiring. However, the current driving circuit is arranged in the row direction wiring. Needless to say, it is good.

[0233]

As described above, according to the present invention,
When correcting the electron emission characteristics of a plurality of electron-emitting devices provided in a matrix in a substantially uniform manner, even if a large number of electron-emitting devices are provided, the electron-generating device and the driving thereof are corrected with a small amount of correction information. A method and an image forming apparatus are provided.

[0234]

[Brief description of the drawings]

FIG. 1 is a block diagram of a driving circuit in an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram of the drive circuit of FIG. 1 mainly showing a circuit used when acquiring correction information regarding a current drive circuit according to the first embodiment of the present invention.

FIG. 3 shows an example of correction information related to a plurality of electron-emitting devices wired in a matrix according to the first embodiment of the present invention.
It is a block diagram at the time of acquiring the correction information regarding the invalid element current of the column direction wiring.

FIG. 4 shows an example of correction information relating to a plurality of electron-emitting devices wired in a matrix according to the first embodiment of the present invention.
FIG. 9 is a block diagram when acquiring correction information relating to a variation in emission current Ie characteristic (electron emission efficiency) with respect to an element current If.

FIG. 5 is a flowchart showing a process of storing correction information in a nonvolatile memory 110 according to the first embodiment of the present invention.

FIG. 6 is a block diagram of a driving circuit in an image forming apparatus according to a third embodiment of the present invention.

FIG. 7 is a block diagram of a driving circuit in an image forming apparatus according to a fourth embodiment of the present invention.

FIG. 8 is a perspective view of a display panel applicable to the present invention.

FIG. 9 is a plan view illustrating a phosphor array of a face plate of the display panel.

FIG. 10 is a plan view illustrating a phosphor array of a face plate of a display panel.

FIG. 11 is a plan view illustrating the configuration of a planar surface conduction electron-emitting device applicable to the present invention.

FIG. 12 is a cross-sectional view illustrating a configuration of a planar type surface conduction electron-emitting device applicable to the present invention.

FIG. 13 is a cross-sectional view for explaining a manufacturing process of a planar surface conduction electron-emitting device applicable to the present invention.

FIG. 14 is a cross-sectional view for explaining a manufacturing process of a flat surface conduction electron-emitting device applicable to the present invention.

FIG. 15 is a cross-sectional view for explaining a manufacturing process of a flat surface conduction electron-emitting device applicable to the present invention.

FIG. 16 is a cross-sectional view for explaining a manufacturing process of a flat surface conduction electron-emitting device applicable to the present invention.

FIG. 17 is a cross-sectional view for explaining a manufacturing process of a planar surface conduction electron-emitting device applicable to the present invention.

FIG. 18 is a diagram showing an applied voltage waveform during energization forming processing.

FIG. 19 is a diagram showing an applied voltage waveform in the energization activation process.

FIG. 20 is a diagram showing a change in emission current Ie at the time of energization activation processing.

FIG. 21 is a schematic cross-sectional view for explaining a basic configuration of a vertical surface conduction electron-emitting device applicable to the present invention.

FIG. 22 is a cross-sectional view illustrating a manufacturing process of a vertical surface conduction electron-emitting device applicable to the present invention.

FIG. 23 is a cross-sectional view illustrating a manufacturing process of a vertical surface conduction electron-emitting device applicable to the present invention.

FIG. 24 is a cross-sectional view illustrating a manufacturing process of a vertical surface conduction electron-emitting device applicable to the present invention.

FIG. 25 is a cross-sectional view illustrating a manufacturing process of a vertical surface conduction electron-emitting device applicable to the present invention.

FIG. 26 is a cross-sectional view illustrating a manufacturing process of a vertical surface conduction electron-emitting device applicable to the present invention.

FIG. 27 is a cross-sectional view illustrating a manufacturing process of a vertical surface conduction electron-emitting device applicable to the present invention.

FIG. 28 is a diagram showing a change in emission current Ie during a current activation process applicable to the present invention.

FIG. 29 is a plan view of a multi-electron beam source applicable to the present invention.

FIG. 30 shows a surface conduction electron-emitting device applicable to the present invention;
FIG. 30 is a cross-sectional view taken along line AA ′ of FIG. 29.

FIG. 31 is a block diagram illustrating a configuration example of an image forming apparatus using a display panel driven by a drive circuit according to the present invention.

FIG. 32 is a plan view showing a structural example of a general surface conduction electron-emitting device.

FIG. 33 is a sectional view showing a structural example of a general FE type cold cathode device.

FIG. 34 is a cross-sectional view showing a structural example of a general MIM cold-cathode device.

FIG. 35 is a diagram showing a wiring example of a plurality of electron-emitting devices arranged in a matrix.

[Explanation of symbols]

 101: image display panel, 102: scanning circuit, 103: decoder, 104: timing signal generation circuit, 105: sample / hold circuit, 106: serial / parallel conversion circuit, 107: pulse width modulation circuit, 108: current drive circuit, 109: high-speed memory, 110: nonvolatile memory, 111: control circuit, 112: external device, 113: switch, 120: current detection circuit, 121: voltage driver, 122: Ie (emission current) monitor circuit,

Continued on the front page F term (reference) 5C080 AA08 AA18 BB05 CC03 DD03 DD30 EE29 EE30 FF12 GG02 GG03 GG05 GG07 GG08 GG12 JJ02 JJ04 JJ05 JJ06 JJ07

Claims (17)

[Claims] 1. A plurality of electron-emitting devices are arranged in a matrix, and one terminal of the electron-emitting devices arranged in the same row is connected to a row wiring and the other of the electron-emitting devices arranged in the same column. Terminals are connected to the column wiring,
In order to drive a selected one of the plurality of electron-emitting devices, a driving circuit drives a row-direction wiring and a column-direction wiring including the selected electron-emitting device based on a driving signal. A generator, wherein at least one nonvolatile memory in which first correction information on the plurality of electron-emitting devices and / or the driving circuit is stored in advance, and the plurality of electron-emitting devices and / or the driving circuit A high-speed memory for storing second correction information related to the first correction information, and control means for expanding the first correction information stored in the non-volatile memory as second correction information in the high-speed memory. An electron generating apparatus for driving the selected electron-emitting device based on second correction information stored in the high-speed memory. 2. The high-speed memory is capable of reading stored information at least at a speed substantially equal to a driving speed of the driving circuit by the electron generating device. Prior to
A current value is calculated based on the second correction information read from the high-speed memory, and control is performed such that the drive circuit drives the selected electron-emitting device based on the current value. Item 2. An electron generator according to Item 1. 3. The first correction information is compressed information, and the control means, when copying the first correction information to the high-speed memory, converts the compressed information into a predetermined data. 3. The electron generator according to claim 2, wherein the electron generator is developed into a size. 4. The non-volatile memory according to claim 1, wherein a plurality of types of correction information are stored, and one of the correction information is copied by the control unit to the high-speed memory. Electron generator. 5. The electron generating apparatus according to claim 4, wherein said plurality of types of correction information are correction information indicating a row direction and / or a column direction characteristic of said plurality of electron-emitting devices. 6. The apparatus according to claim 4, further comprising communication means for communicating with an external device, wherein the control means selects correction information designated by the external device from among the plurality of types of correction information. Or the electron generator according to claim 5. 7. A method according to claim 1, wherein said plurality of types of correction information include:
The electron generating apparatus according to claim 4, further comprising an input unit configured to select any one of the correction information, wherein the control unit selects the specified correction information. 8. The electron emission device according to claim 1, wherein the electron emission device is a surface conduction type electron emission device.
An electron generator according to any one of the above. 9. A plurality of electron-emitting devices arranged in a matrix according to an input image signal by the electron-generating device according to claim 1, wherein the plurality of electron-emitting devices are driven. An image forming apparatus for forming an image on a display panel including an element. 10. An image forming apparatus having a plurality of image forming elements, comprising: a first memory for storing first information; and a second memory for storing information input from the first memory as second information. An image forming apparatus, comprising: a second memory; and a driving unit configured to supply a drive signal corrected based on the second information to the image forming element. 11. The first information is obtained by compressing information used as the second information, and
2. The image processing apparatus according to claim 1, further comprising a developing unit configured to develop the first information output from the first memory to the second memory.
0. An image forming apparatus according to 12. The read speed of the second memory required to correct the drive signal.
An image forming apparatus according to claim 11. 13. The image forming apparatus according to claim 10, wherein said first memory is a nonvolatile memory. 14. A plurality of electron-emitting devices are arranged in a matrix, one terminal of the electron-emitting devices arranged in the same row is connected to a row-directional wiring, and the other of the electron-emitting devices arranged in the same column. Are connected to the column-direction wiring, and among the plurality of electron-emitting devices, in order to generate electrons from the selected electron-emitting device, a row-direction wiring and a column-direction wiring including the selected electron-emitting device are included. A driving circuit for driving the electron generating device based on a driving signal, wherein the first correction information on the plurality of electron-emitting devices and / or the driving circuit is stored in one or more nonvolatile memories. When the power of the electron generator is turned on, the first correction information stored in the nonvolatile memory is expanded in the high-speed memory as the second correction information, and is output from the high-speed memory. And driving the selected electron-emitting device by the drive circuit based on the second correction information. 15. An electron emission efficiency of the selected electron-emitting device, wherein one of the plurality of electron-emitting devices is selected, and a voltage pulse signal having a predetermined pulse width is applied to the selected electron-emitting device. The emission current value representing the amount of electron beam emitted by the selected electron-emitting device by the application of the voltage pulse signal is expressed by:
15. The method according to claim 14, wherein the value is obtained by dividing by a value of a current flowing through the selected electron-emitting device. 16. A reactive element current flowing in a row direction or a row direction wiring to which the selected electron-emitting device is connected, wherein all the row-direction or column-direction wirings of the plurality of electron-emitting devices are set to zero potential, One of the wirings in a direction different from the wiring having the potential is selected, a voltage pulse signal having a predetermined pulse width is applied to the wiring of the selected row or column, and the selection is made by applying the voltage pulse signal. 15. The method according to claim 14, wherein the current value is obtained by measuring a current value flowing in a row or a column wiring. 17. The input / output characteristics of the drive circuit are as follows: a predetermined current value is set for the drive circuit, and a current value output by the drive circuit is measured in accordance with the setting of the predetermined current value. The method according to claim 14, wherein the measured output current value and the predetermined current value are obtained by approximating a straight line passing through the origin.