JPH11133911A - Image formation method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation method and device which suppress the deviation in the reach position of electrons emitted from a cold cathode element to the minimum, while suppressing the emission luminance in the image formation panel. SOLUTION: A video detecting part 73 detects the luminance of an picture displayed on a display panel 61 based on the input picture signal and the result is outputted to a system control part 74 as a luminance signal s11. the system control part 74 examines whether the luminance signal s11 is a reference value or more, and if it is more, a signal s21 is outputted to the luminance adjustment part 78. The luminance adjustment part 78 outputs a signal s16 and a signal s18 to a Vf control part 75 and a high voltage generation part 77 respectively based on this signal s21 so as to hold such a relation of setting the ratio Vf (drive voltage for the cold cathode emission element)/Va (high anode voltage) to a prescribed value, and the voltage Vf and Va are so changed as to suppress the emission luminance in the display panel 61.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method and apparatus using electron-emitting devices, and more particularly to an image forming method and apparatus using an image forming panel in which a plurality of electron-emitting devices are arranged on a two-dimensional plane. It is about.

[0002]

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

[0003] As a surface conduction type emission element, for example, M.
I. Elinson, Radio E-ng. Electron Phys., 10, 1290,
(1965) and other examples described later.

The surface conduction electron-emitting device utilizes a phenomenon in which an electron is emitted when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. Examples of the surface conduction electron-emitting device include a device using an SnO2 thin film by Elinson et al., And a device using an Au thin film [G. Dittmer: “Thin Solid Films”, 9,317 (1)
972)] and those based on In2O3 / SnO2 thin films [M. Hart
well and CG Fonstad: "IEEE Trans. ED Conf."
519 (1975)] and those using carbon thin films [Hisashi Araki
Others: Vacuum, Vol. 26, No. 1, 22 (1983)].

[0005] As a typical example of the device configuration of these surface conduction electron-emitting devices, FIG. 23 is a plan view of the device by M. Hartwell et al. Described above. In the figure, reference numeral 3001 denotes a substrate, and reference numeral 3004 denotes a conductive thin film made of a metal oxide formed by sputtering. The conductive thin film 3004 is formed in an H-shaped planar shape as shown. An electron emission portion 3005 is formed by applying an energization process called energization forming to be described later to the conductive thin film 3004. The interval L in the figure is 0.5 to 1 [mm], and the width W is
It is set to 0.1 [mm]. 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. In the above-described surface conduction electron-emitting device including the device by M. Hartwell et al., It is common to form an electron-emitting portion 3005 by subjecting the conductive thin film 3004 to an energization process called energization forming before performing electron emission. It was a target. The energization forming is, for example, to apply a constant DC voltage to both ends of the conductive thin film 3004 or to apply a DC voltage which is boosted at a very slow rate of, for example, about 1 V / min, to energize the conductive thin film 304.
04 is locally destroyed or deformed or altered,
This is to form the electron-emitting portion 3005 in a state of being electrically high in resistance. Note that a crack is generated in a part of the conductive thin film 3004 that is locally broken, deformed, or altered.
When an appropriate voltage is applied to the conductive thin film 3004 after the energization forming, electron emission is performed in the vicinity of the crack.

As an example of the FE type, for example, WP Dyke
& WW Dolan, “Field emission”, Advance in Ele
ctron Physics, 8, 89 (1956) or CA Spind
t, “Physical properties of thin-film field emissi
on cathodes with molybdeniumcones ”, J. Appl. Phy
s., 47, 5248 (1976).

As a typical example of the FE type device configuration, FIG. 24 shows a cross-sectional view of the device by CA Spindt et al. In the figure, 3010 is a substrate, 3011 is an emitter wiring made of a conductive material, 3012 is an emitter cone, 3013 is an insulating layer, and 3014 is a gate electrode. This device comprises an emitter cone 3012 and a gate electrode 3
By applying an appropriate voltage during 014, field emission is caused from the tip of the emitter cone 3012. As another element configuration of the FE type, FIG.
There is also an example in which an emitter and a gate electrode are arranged on a substrate almost in parallel with the substrate plane instead of the laminated structure as described above.

[0008] Examples of the MIM type include, for example, C.I.
A. Mead, “Operation of tunnel-emission Devices,
J. Appl. Phys., 32,646 (1961) and the like are known.
FIG. 25 shows a typical example of this MIM type element configuration.
The figure is a cross-sectional view, in which 3020 is a substrate,
3021 is a lower electrode made of metal, 3022 is a thickness of 100
An insulating layer as thin as about Å, and 3023 has a thickness of 8
The upper electrode is made of a metal of about 0 to 300 angstroms. 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.

The above-mentioned cold cathode device can obtain electrons at a lower temperature than the hot cathode device, and therefore does not require a heater for heating. Therefore, the structure is simpler than that of the hot cathode element, and a fine element can be produced. Further, even when a large number of elements are arranged on a substrate at a high density, problems such as thermal melting of the substrate hardly occur. Also, unlike the response speed is slow because the hot cathode element operates by heating the heater,
In the case of a cold cathode device, there is also an advantage that the response speed is high. For this reason, research for applying the cold cathode device has been actively conducted.

For example, the surface conduction electron-emitting device has the advantage of being able to form a large number of devices over a large area because it has a particularly simple structure and is easy to manufacture among the cold cathode devices. Therefore, for example, Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent Publication No. 32, a method for arranging and driving a large number of elements has been studied.

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

Particularly, as an application to an image display device, for example, as disclosed in US Pat. No. 5,066,883, JP-A-2-257551 and JP-A-4-28137 by the present applicant, surface conduction is disclosed. An image display device using a combination of a mold emission element and a phosphor that emits light by electron irradiation has been studied. An image display device using a combination of a surface conduction electron-emitting device and a phosphor is expected to have better characteristics than other conventional image display devices. For example, compared to a liquid crystal display device that has become widespread in recent years, it can be said that it is excellent in that it is a self-luminous type and does not require a backlight and has a wide viewing angle.

A method of arranging and driving a large number of FE elements is disclosed in, for example, US Pat. No. 4,904,89 by the present applicant.
5 is disclosed. Further, as an example of applying the FE type to an image display device, for example, a flat panel display device reported by R. Meyer et al. Is known. [R. Meyer: “Recent D
evelopment on Microtips Display at LETI ”, Tech.Di
gest of 4th Int.Vacuum Microelectronics Conf., Na
gahama, pp. 6-9 (1991)].

An example in which a number of MIM types are arranged and applied to an image display device is disclosed in, for example, Japanese Patent Application Laid-Open No.
No. 5738.

The inventors of the present application have tried cold cathode devices of various materials, manufacturing methods, and structures, including those described in the above prior art. Further, research has been conducted on a multi-electron source in which a large number of cold cathode devices are arranged, and on an image display device using the multi-electron source.

The present inventors have attempted to manufacture a multi-electron source by, for example, an electrical wiring method shown in FIG.
That is, it is a multi-electron 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 wiring in a row direction, and 4003 shows a wiring in a column direction. Row direction wiring 4002 and column direction wiring 4003
Actually have a finite electrical resistance, but are shown as wiring resistances 4004 and 4005 in the figure. The above-described wiring method is called simple matrix wiring. Note that, for convenience of illustration, the matrix is shown as a 6 × 6 matrix, but the size of the matrix is not limited to this. For example, in the case of a multi-electron source for an image display device, a desired image is displayed. In this case, only enough elements are arranged and wired.

In a multi-electron source in which cold cathode elements are arranged in a simple matrix wiring, an appropriate electric signal is applied to the row wiring 4002 and the column wiring 4003 in order to output a desired electron beam. For example, in order to drive 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 at the same time, the row direction wiring 4002 of the non-selected row is not driven. A selection voltage Vns is applied. In synchronization with this, a driving voltage Ve for outputting electrons is applied to the column wiring 4003. According to this method, if the voltage drop due to the wiring resistances 4004 and 4005 is ignored, the voltage (Ve−
Vs) is applied, and a voltage (Ve-Vns) is applied to the cold cathode elements in the non-selected rows. These voltages Ve, Vs, Vn
If s is a value of an appropriate size, electrons of a desired intensity should be output only from the cold cathode elements of the selected row,
If a different drive voltage Ve is applied to each of the column wirings, electrons of different intensities should be output from each of the elements in the selected row. Further, if the length of time during which the drive voltage Ve is applied is changed, the length of time during which electrons are output should be changed. Therefore, the multi-electron source in which the cold cathode elements are arranged in a simple matrix wiring has various application possibilities. For example, if an electric signal corresponding to image information is appropriately applied, the multi-electron source can be suitably used as an electron source for an image display device. .

[0019]

In an image display apparatus using the above-described cold cathode type electron emitting device (electron emitting device) as an electron source, electrons emitted from the cold cathode type electron emitting device are subjected to a high anode voltage (hereinafter, referred to as "high voltage"). Va) and collides with the phosphor. However, the power consumption of the device increases as the number of cold cathode type emission elements increases. For example, assuming that the number of cold-cathode emission devices is (m × n), the power consumption W generated in the high voltage portion is as follows: W = (m × n) × Ie × Va (Va is the drive time per unit time, Ie is 1 Emission current emitted from one element) (1). For example, when applied to an image display device for displaying a television signal or a computer signal, the number of cold cathode type emission elements becomes enormous. An increase in power consumption is a major problem. In addition, when the number of cold cathode type emission elements is increased, there is also a problem that the heat generation of the fluorescent plate colliding with the emitted electrons increases.

The light emission luminance of such an image display device is determined by the amount of electrons emitted from the electron-emitting devices or the energy at which the emitted electrons collide with the phosphor. The brightness was adjusted by changing the energy of the electrons colliding with the phosphor. That is, the voltage applied to the electron-emitting device or the acceleration voltage applied between the phosphor and the electron-emitting device is changed.

Here, to reduce the power consumption W, the above equation is used.
As is apparent from (1), it is sufficient to lower the emission current Ie or the anode voltage Va, that is, to reduce the emission luminance. However, when the power consumption is adjusted by reducing the emission current Ie or the anode voltage Va, the following problems have occurred.

If the emission luminance is adjusted by reducing the device voltage applied to the electron-emitting device to reduce the emission current Ie, the power consumption is certainly reduced. However, the position where the emitted electrons collide with the phosphor is determined by the position of the device. It fluctuates with a change in voltage. As a result, for example, the emitted electrons collide with an adjacent phosphor without colliding with a phosphor of a desired color, or a color shift occurs due to a collision with a black stripe. A similar problem occurs when the anode voltage applied between the phosphor and the electron-emitting device is changed.

As a result of intensive studies, the present inventors have found the cause of the above problem. This will be described with reference to FIGS.

In these electron-emitting devices, electrons emitted from the electron-emitting portion 23 generally have an initial velocity component in a direction from the negative electrode 22 to the positive electrode 21. Therefore, the emitted electrons do not travel in the vertical direction. Furthermore, since the positive electrode 21 and the negative electrode 22 are arranged in a plane of the substrate,
When a driving voltage Vf is applied between the positive electrode 21 and the negative electrode 22, the distribution of electrons generated in the space above the electron emitting portion 23 is asymmetric with respect to a line passing through the electron emitting portion 23 and perpendicular to the substrate plane. Distribution. That is, the distribution is asymmetric with respect to the one-dot chain line in FIG. In FIG. 27A, the potential distribution between the electron-emitting device and the target 24 is indicated by a dotted line. As shown, the equipotential surface indicated by the dotted line is substantially parallel to the substrate plane near the target 24, but inclined near the electron-emitting device due to the drive voltage Vf [V] as shown. Becomes For this reason, the electrons emitted from the electron emitting portion 23 receive a force in the Z direction due to the oblique potential while flying in the space, and also receive a force in the X direction. Draw.

For the above two reasons, the position where the emitted electrons irradiate the target 24 is shifted from the position vertically above the electron emitting portion 23 by the distance Lef in the X direction. FIG. 27 (B) is a plan view when viewed from above the target 24, and 25 in the figure schematically shows the electron irradiation position on the lower surface of the target (FIG. 27 (A) is a plan view). The dashed-dotted line JJ ′ in FIG.
FIG. 4 is a cross-sectional view showing a state cut along the line.

Therefore, in order to generalize how the electron irradiation position 25 of the target 24 deviates from the position vertically above the electron emitting portion 23, the direction and distance of the deviation are conveniently described using a vector Ef. To express.

First, the direction of the vector Ef is such that the negative electrode 22 of the electron-emitting device and the positive electrode 21 of the electron-emitting portion 23 are positioned on the substrate plane.
It can be said that it is equal to the direction in which. For example, FIG.
In the case of (A), since the negative electrode 22, the electron emitting portion 23, and the positive electrode 21 of the electron-emitting device are arranged in order on the substrate 20 along the X direction, the vector Ef has the same direction as the X direction. Note that, for convenience of illustrating the direction in which the electron-emitting devices are formed on the plane of the substrate 20 and the direction of the vector Ef, these will be schematically represented by a method illustrated in FIG. FIG. 28 shows an example in which the negative electrode, the electron-emitting portion, and the positive electrode of the electron-emitting device 26 are formed on the substrate 20 side by side along the X direction.

The magnitude of the vector Ef (that is, Le
f) is determined depending on the distance Lh between the electron-emitting device 26 and the target, the driving voltage Vf of the electron-emitting device 26, the potential Va of the target, the type and shape of the electron-emitting device 26, etc.
A rough numerical value can be calculated by the following equation (2).

Ref = 2 × K × Lh × SQRT (Vf / Va) (2) where Lh [m] is the distance between the electron-emitting device and the target, Vf is the device voltage applied to the electron-emitting device, and Va
Denotes a voltage applied to the target, K denotes a constant determined by the type and shape of the electron-emitting device, and SQRT () denotes a square root of ().

In the above equation (2), when a rough numerical value is obtained, if the type or shape of the electron-emitting device to be used is unknown, K = 1 is substituted. If the type and shape of the electron-emitting device are known, the constant K of the electron-emitting device is determined by experiment or computer simulation. Further, in order to obtain Lef with higher accuracy, it is desirable that K be a function of Vf instead of a constant. However, a constant is often sufficient for the accuracy required when designing an image display device. .

The present invention has been made in view of the above-mentioned conventional example. For example, an image capable of minimizing a shift in the arrival position of electrons emitted from an electronic element when suppressing light emission luminance in an image forming panel. It is an object to provide a forming method and an apparatus.

Another object of the present invention is to reduce the power consumption and the heat generation of the image forming panel by changing the device voltage applied to the device and the accelerating voltage for accelerating electrons when the light emission luminance is equal to or higher than a predetermined value. An object of the present invention is to provide an image forming method and an apparatus for suppressing the image formation.

It is another object of the present invention to provide an image forming method and apparatus capable of suppressing color misregistration in a formed image and suppressing power consumption and heat generation.

[0034]

In order to achieve the above object, an image forming apparatus according to the present invention has the following arrangement.
That is, an image forming apparatus having an image forming panel in which a plurality of electron-emitting devices are arranged, wherein a driving voltage generating means for generating a driving voltage for driving each of the electron-emitting devices; Acceleration voltage generation means for generating an acceleration voltage for accelerating electrons, brightness detection means for detecting the brightness of an image displayed on the display panel based on the input image signal, and detection by the brightness detection means And a control unit that controls the driving voltage generation unit and the acceleration voltage generation unit such that a ratio between the driving voltage and the acceleration voltage becomes substantially the same based on the luminance.

In order to achieve the above object, the image forming method of the present invention comprises the following steps. That is, an image forming method for forming an image on an image forming panel on which electron-emitting devices are arranged, comprising: a luminance detecting step of detecting a luminance of an image displayed on the display panel based on an input image signal; Based on the brightness detected in the detection process,
A control step of controlling to change the values of the drive voltage and the acceleration voltage so that the ratio between the drive voltage and the acceleration voltage becomes substantially the same. The present invention is effective when the electron-emitting device generates an electric field having a component perpendicular to the application direction of the acceleration voltage due to the driving voltage. When a plurality of electron-emitting devices are arranged, they are preferably arranged in a matrix.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing embodiments of the present invention, an outline of the present invention will be briefly described.

FIG. 10 is a diagram showing a change in light emission luminance when the element voltage Vf is changed linearly while the ratio of Vf / Va is kept constant. As is clear from FIG.
The electron emission amount increases exponentially with respect to the device voltage Vf applied to the device.

In the embodiment of the present invention, there are provided means for detecting or predicting the light emission luminance of the image display device and outputting the result as a luminance evaluation value, and means for controlling the light emission luminance based on the luminance evaluation value. By suppressing the average density of the entire light-emitting screen from exceeding a predetermined value, it is possible to realize a high-quality image display device which suppresses an increase in power consumption and heat generation of a fluorescent plate and has no color shift or the like.

As shown in the above equation (2), SQRT (Vf
If / Va) is kept constant, Lef will be constant, and there will be no displacement of electrons that collide with the phosphor. In this case, the voltage Va applied to the phosphor and the voltage Vf applied to the electron-emitting device
Are controlled simultaneously so that the ratio between the two is constant. At this time, as described in the related art, SQ
Since the value of RT (Vf / Va) is not proportional to the emission luminance,
The amount of change with respect to the luminance adjustment amount is determined and Va and Vf are determined and controlled so that a desired luminance change is performed on the luminance adjustment signal. As described above, the electron-emitting device used in the embodiment of the present invention includes a positive electrode, a negative electrode, and an electron-emitting portion as constituent members, and these constituent members are formed side by side on the substrate plane (the negative electrode is not limited to the negative electrode). Some of the elements may also serve as electron emission portions). As a device satisfying such requirements, for example, a surface conduction electron-emitting device and a horizontal field emission device can be cited. Hereinafter, the surface conduction electron-emitting device and the horizontal field emission device will be described in this order. The surface conduction electron-emitting device includes, for example, the conventional embodiment shown in FIG. As for the former, various materials are already known as described in the section of the prior art, but all of them are suitable as the electron-emitting device used in the embodiment of the present invention. Regarding the latter, materials, configurations, manufacturing methods, and the like will be described in detail in embodiments described below, but all are suitable as electron-emitting devices used in the present invention.
That is, when a surface conduction electron-emitting device is used in the embodiment of the present invention, the material, configuration, manufacturing method, and the like of the device are not particularly limited.

As for the surface conduction electron-emitting device,
The vector Ef indicating the direction in which the electrons are deflected has the direction shown in FIG. 7A is a cross-sectional view, and FIG. 7B is a plan view, in which 40 is a substrate, 41 is a positive electrode, 42 is a negative electrode,
Reference numeral 3 denotes an electron emitting unit, and VF denotes a power supply for applying a driving voltage to the surface conduction electron-emitting device. Next, the horizontal field emission device refers to a field emission device in which a negative electrode 42, an electron emission portion 43, and a positive electrode 41 are arranged side by side along a substrate plane. For example, the device of the prior art (conventional FIG. 2) is not included in the horizontal category because the negative electrode: the electron emission portion and the positive electrode are provided in the direction perpendicular to the substrate plane. Elements illustrated in (C) to (C) are included in a horizontal category.

FIGS. 8A to 8C are perspective views showing a typical example in which a horizontal electron-emitting device is formed on a substrate plane along the X direction.

In the drawing, reference numeral 50 denotes a substrate, 51 denotes a positive electrode, 52 denotes a negative electrode, and 53 denotes an electron emitting portion. The horizontal electron-emitting device may have various shapes other than the one illustrated in FIG. 8, but in short, as described above with reference to FIG. 4, the trajectory of the electron beam is deflected from the vertical direction. If it does, it is suitable as an element used in the embodiment of the present invention. Therefore, for example, a configuration in which a modulation electrode for modulating the intensity of an electron beam is added to the configuration shown in FIGS. In addition, the electron emission portion 53 may be a part of the negative electrode serving as the negative electrode, or may be a member added on the negative electrode. Examples of the material used for the electron emission portion of the horizontal field emission device include a high melting point metal and diamond. However, the material is not limited to this, as long as the material emits electrons well.

Further, for the horizontal field emission device, the vector Ef indicating the direction in which the electron beam is deflected is shown in FIG.
The orientation is as shown in (A) and (B). FIG. 9A is a cross-sectional view,
(B) is a plan view, in which 50 is a substrate, 51 is a positive electrode, 52 is a negative electrode, 53 is an electron-emitting portion, and VF is a power supply for applying a drive voltage to the element.

As described above, the electron-emitting device suitable for use in the present invention has been described. In the image display device of the present embodiment, a surface-conduction type electron-emitting device is used.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a configuration of an image display device according to an embodiment of the present invention.

In the figure, reference numeral 61 denotes an image display panel according to the present embodiment, which is horizontal (480 pixels in the row 9 direction;
In the vertical (column) direction, 240 phosphors are arranged in the form of vertical stripes in the order of R, G, B, and the electron-emitting devices corresponding to each phosphor are formed by row wiring and column wiring (240 × 48).
In the following, an example will be described in which the elements of the image display panel 61 are driven in a line-sequential manner.

The input television (TV) signal s1
Are decoded into R, G, and B signals by a decoder unit 62 and input to an analog preprocessing unit 63. The analog preprocessing unit 63 includes a synchronization separation circuit, a color adjustment circuit,
It has circuits such as a contrast control circuit, a DC reproduction circuit, a brightness control circuit, a matrix circuit, and a low-pass filter. The signal level control, the DC reproduction, and the band-limited R, G, and B signals are each converted to a corresponding A / D signal. Output to converters 64a to 64c. Further, in addition to outputting a synchronizing signal (sync) for PLL control to the timing control unit 65, a luminance signal s20 obtained by mixing the R, G, and B signals in the matrix unit is sent to the video detection unit 73.

Each of the A / D converters 64a to 64c samples each analog R, G, B signal according to the sampling clock s2 from the timing control unit 65 and converts it into a digital signal having a predetermined number of gradations. The digital processing unit 66, which has received the digital image signal s9 from the A / D converters 64a to 64c, performs gamma processing and digital filter processing for edge enhancement and noise suppression on the image signal s9. Is output to the data rearranging section 67 as a digital signal. Further, the digital processing unit 66 also performs contour enhancement control and contrast control based on the coefficient data s15 from the system control unit 74.

As shown in the horizontal timing chart of FIG. 3, the data rearranging section 67 converts R, G,
B, each of the 160 data (s9) is compressed in the time axis direction as shown by serial image data s10, and the RGB data is rearranged in an order corresponding to the color arrangement of the phosphors.
The data is transferred to the shift register 68 as 480 serial image data per line.

The shift register 68 reads the serial image data s10 in synchronization with the shift clock s6, and
The serial image data consisting of 480 lines of data is converted into parallel data and sent to the modulation signal generator 69 during the horizontal blanking period.

In the present embodiment, the modulation signal generator 69 modulates parallel data (image data) input from the shift register 68 by a pulse width modulation method, so that one line of the display panel 61 is controlled. It has 480 (160 pixels) pulse width modulators corresponding to the number of emission elements. Then, during one horizontal period, a pulse signal having a time width proportional to the size of the image data input to each pulse width modulator is generated based on the pulse width modulation signal s7 and output to the horizontal drive driver 70. I do. The horizontal driving driver 70 controls the voltage amplitude Ve of the pulse signal applied to the electron-emitting device by the signal s17 from the Vf control unit 75 and outputs the voltage to the display panel 61.

As shown in the vertical timing diagram of FIG. 2, a shift register 71 for inputting a timing signal s8 (V_START, H_CLK) for row scanning output from the timing control unit 65 is provided in the row wiring of the display panel 61. And outputs a row selection signal to the vertical drive driver 72 for selecting and driving and scanning the electron-emitting device connected to. The vertical drive driver 72 includes switching elements such as transistors for 240 rows of the display panel 61, and each of these switching elements becomes conductive when a row-direction wiring is selected, and a bias voltage output from the Vf control unit 75. Vs is applied to the selected row-direction wiring of the display panel 61.

Each time one row direction wiring is selected and driven in this manner, one line of image data corresponding to the selected row is output from the horizontal driving driver 70 and is output to the display panel 61. Images are displayed line-sequentially.

FIG. 4 shows a system control unit 74 according to this embodiment.
FIG. 3 is a block diagram showing the configuration of FIG.

In FIG. 4, the system control unit 74 of the present embodiment includes a CPU 81, a ROM 82, a RAM 83,
The CPU 81 includes an EPROM 84, an A / D converter 85, a D / A converter 86, and an I / O port 87. The CPU 81 executes a control process based on a control program stored in a ROM 82 to control the entire apparatus. D /
Output signals s13 and s14 of the A converter 86 are control signals for contrast control and brightness control.
These signals are transmitted to the analog pre-processing unit 63, and control the levels of the R, G, and B signals and the amount of DC reproduction. The brightness adjustment signal s21 is a control signal for controlling the brightness adjustment unit 78 to reduce power consumption.

Returning to FIG. 1, the user interface unit 76 transmits a user request such as image quality adjustment to the system control unit 74 and displays various information output from the system control unit 74. Are exchanged by a signal s12.

The video detection unit 73 converts the luminance signal s20 output from the analog preprocessing unit 63 into a gate signal s5 for each field to which horizontal blanking is added, which is output from the timing control unit 65 (see FIG. 2). ), An average value of the luminance signal s20 is detected for each field, and an average luminance signal s11 indicating the detection result is output to the system control unit 74. This average luminance signal s11
Is converted into a digital signal by the A / D converter 85 in FIG. And
The CPU 81 compares the input digital average luminance value with the reference value, and outputs a luminance adjustment signal s21 to the luminance adjustment section 78 when the digital average luminance value is larger than the reference value.

FIG. 5 is a block diagram showing the structure of the brightness adjusting section 78.

In FIG. 5, reference numeral 91 denotes a Vf control ROM;
Reference numeral 92 denotes a Va control ROM, which inputs the luminance adjustment signal s21 as an address signal and outputs instruction data s16 and s18 for increasing and decreasing the corresponding Vf and Va values. The instruction data stored at the same address in the ROMs 91 and 92 are set to values such that the ratio between the element voltage Vf and the anode voltage Va becomes constant, as described above. The instruction data s16 is a control signal for controlling the value of the applied voltage Vf applied to the selected electron-emitting device, and is input to the Vf control unit 75. The instruction data s18 is output to a high-voltage generator 77 that outputs an anode voltage Va for accelerating electrons emitted from the electron-emitting device, and the value of the high-voltage Va output therefrom is controlled. The element voltage Vf and the anode voltage Va are controlled so that the ratio between the voltage pulse amplitude Vf and the acceleration voltage Va is substantially constant. As a result of this control, the light emission luminance of the display panel 61 can be controlled to a certain reference value or less in a state where there is no shift in the electron beam position.

FIG. 6 shows a system control unit 74 of this embodiment.
Is a flowchart showing the control processing in the above, and a control program for executing this processing is stored in the ROM 82.

First, in step S31, the average luminance signal s11 detected by the video detector is input, and in step S32
Then, it is determined whether or not the value of the average luminance signal s11 is larger than the reference value. If it is larger than the reference value, step S3
3, the voltage amplitude Ve controlled by the signal s17 output from the Vf control unit 75 and the bias voltage Vs are controlled, and the anode voltage Va output from the high voltage generation unit 77 is controlled.
And outputs a brightness adjustment signal s21 for controlling. Thus, when the value of the average luminance signal s11 is equal to or greater than the reference value, the ratio between the element voltage Vf applied to each element by the Vf control unit 75 and the anode voltage Va is substantially constant at Vf / Va. The state is changed, and as a result, the average luminance is reduced, and power consumption and heat generation of the phosphor can be suppressed.
In addition, the voltage control does not change the position (Lef) at which electrons collide with the phosphor, so that it is possible to prevent a color shift or the like of a displayed image.

In the above example, in the display panel 61 in which the R, G, and B phosphors are arranged in a vertical stripe,
An example has been described in which the device voltage Vf and the anode voltage Va applied to each device are controlled based on the brightness evaluation value based on the brightness signal s20 from the analog pre-processing unit 63 to suppress the light emission brightness. In this case, the luminance signal s20 contains R,
Although the G and B signals are mixed at the same ratio (eg, luminance signal s20 = (R + G + B) / 3), for example, when the numbers of R, G, and B phosphors are different like a checkered arrangement, The luminance signal s20 is generated at that rate.

Further, in order to obtain a luminance signal for obtaining the light emission luminance of the display panel 61, means for detecting the average high-voltage anode current in the high-voltage generation unit 77 or the average supply current of the power supply line for supplying power to the high-voltage generation unit 77 Means for detecting the average high-voltage anode current detected by these means,
Alternatively, the signal s22 indicating the average supply current is supplied to the system control unit 7
4 may be output. <Description of Manufacturing Method and Application of Surface Conduction Emission Element of Present Embodiment> FIG. 11 is an external perspective view of a display panel 1000 of the present embodiment, and a part of the display panel 1000 is shown in order to show its internal structure. It is shown cut out.

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

The rear plate 1005 has a substrate 1001
Are fixed, but N × M surface-conduction emission devices 1002 are formed on the substrate 1001 (where N and M are positive integers of 2 or more, and the desired number of display pixels) For example, in a display device for displaying high-definition television, N = 300.
It is desirable to set 0, M = 1000 or more.
In the present embodiment, N = 3072, M = 1024
And). The N × M surface conduction electron-emitting devices 1002
Are M row-directional wirings 1003 and N column-directional wirings 10
04 is a simple matrix wiring. 100
The portion constituted by 1 to 1004 is called a multi-electron source. The manufacturing method and structure of the multi-electron source will be described later in detail.

In the present embodiment, the configuration is such that the substrate 1001 of the multi-electron source is fixed to the rear plate 1005 of the airtight container. However, when the substrate 1001 of the multi-electron source has sufficient strength, The substrate 1001 of the multi-electron source may be used as the rear plate of the airtight container.

On the lower surface of the face plate 1007, a fluorescent film 1008 is formed. Since the display panel 1000 of this embodiment is for color display, phosphors of three primary colors of red (R), green (G), and blue (B) used in the field of CRT are provided on the fluorescent film 1008. It is painted separately. The phosphor of each color is, for example, as shown in FIG.
The black conductor 1010 is provided between the stripes of the phosphor of each color as shown in FIG. The purpose of providing the black conductor 1010 is to prevent the display color from being shifted even if the electron irradiation position is slightly shifted, or to prevent the reflection of external light to prevent the reduction of the display contrast. This is to prevent charge-up of the fluorescent film by electrons. 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. 1 shows how to paint the three primary color phosphors.
The arrangement is not limited to the stripe arrangement shown in FIG. 2A, and may be, for example, a delta arrangement as shown in FIG. 12B or another arrangement. Note that when a monochrome display panel is manufactured, a single-color 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 to improve the light utilization rate by mirror-reflecting a part of the light emitted from the fluorescent film 1008 so that the fluorescent film 1
008, to act as an electrode for applying an electron accelerating voltage, and to make the fluorescent film 1008 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 aluminum thereon. Note that when a fluorescent material for low voltage is used for the fluorescent film 1008, the metal back 1009 is not used.

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

Dx1 to DxM, Dy1 to DyN, and Hv are electric connection terminals having an airtight structure provided for electrically connecting the display panel 1000 to an electric circuit (not shown). Dx1 to DxM are the row direction wirings 1 of the multi-electron source
003 and Dy1 to DyN are the column wirings 10 of the multi-electron source.
04 and Hv are the metal back 100 of the face plate
9, respectively.

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

As described above, the display panel 1 according to the embodiment of the present invention
000 has been described.

Next, the display panel 100 of this embodiment is described.
A method for manufacturing the multi-electron source used for the first embodiment will be described.
The multi-electron source used for the image display device of the present embodiment is
There is no limitation on the material, shape, or manufacturing method of the surface conduction electron-emitting device as long as it is an electron source in which the surface conduction electron-emitting devices are arranged in a simple matrix. However, 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 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 source of a high-luminance, large-screen image display device. Therefore, in the display panel of the above embodiment, a surface conduction electron-emitting device in which the electron-emitting portion or its peripheral portion is formed of a fine particle film is used. Therefore, the basic structure, manufacturing method and characteristics of a suitable surface conduction electron-emitting device will be described first, and then the structure of a multi-electron 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 Type Emission Device) A typical configuration of a surface conduction type emission device in which an electron emission portion or its peripheral portion is formed from a fine particle film is a flat type or a vertical type. Kinds are given.

(Planar surface conduction electron-emitting device) First, the structure and manufacturing method of a plane surface conduction electron-emitting device will be described. FIG. 13 shows a plan view (A) and a cross-sectional view (B) for describing the configuration of a planar surface conduction electron-emitting device. In the figure, 1101 is a substrate, 1102 and 1103 are device electrodes, 1104 is a conductive thin film, 1105
Are electron-emitting portions formed by an energization forming process;
Reference numeral 113 denotes a thin film formed by the activation process.

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 formed on the various substrates described above. A stacked substrate or the like can be used.

The device electrodes 1102 and 1103 provided on the substrate 1101 in parallel with the substrate surface are formed of a conductive material. For example, N
i, Cr, Au, Mo, W, Pt, Ti, Cu, Pd,
Materials may be appropriately selected and used from metals such as Ag and the like, alloys of these metals, metal oxides such as In 2 O 3 —SnO 2, and semiconductors such as polysilicon. The electrodes can be easily formed by using a combination of a film forming technique such as vacuum evaporation and a patterning technique such as photolithography and etching. However, the electrodes can be formed using other methods (for example, printing techniques). I can't wait.

The shapes of the device electrodes 1102 and 1103 are appropriately designed according to the application purpose of the electron-emitting device.
Generally, the electrode interval L is usually designed by selecting an appropriate value from the range of several hundreds of angstroms to several hundreds of micrometers. However, for application to a display device, it is preferable that the electrode spacing L be more than a few micrometers. It is in the range of ten micrometers. As for the thickness d of the device electrode, an appropriate numerical value is usually selected from a range of several hundred angstroms to several micrometers.

A fine particle film is used for the conductive thin film 1104. The fine particle film described here refers to a film including a large number of fine particles as constituent elements (including an island-shaped aggregate). When the fine particle film is examined microscopically, usually, a structure in which the individual fine particles are spaced apart from each other, a structure in which the fine particles are adjacent to each other, or a structure in which the fine particles overlap each other is observed.

The particle size of the fine particles used in the fine particle film is in the range of several angstroms to several thousand angstroms, and particularly 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, conditions necessary for good electrical connection to the element electrode 1102 or 1103, conditions necessary for performing energization forming described later, and
Conditions necessary for setting the electric resistance of the fine particle film itself to an appropriate value described later, and the like. Specifically, it is set in the range of several Angstroms to several thousand Angstroms, but the range is preferably between 10 Angstroms and 500 Angstroms.

Examples of materials that can be used to form the fine particle film include Pd, Pt, Ru, Ag,
Au, Ti, In, Cu, Cr, Fe, Zn, Sn, T
a, W, Pb and other metals, PdO, Sn
Oxides such as O2, In2O3, PbO, Sb2O3, etc .; HfB2, ZrB2, LaB6, CeB6, YB
4, borides such as GdB4, TiC, Zr
Carbides such as C, HfC, TaC, SiC, WC, etc .; nitrides such as TiN, ZrN, HfN, etc .; semiconductors such as Si, Ge, etc .; and carbon. Are appropriately selected from these.

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

The conductive thin film 1104 and the device electrode 11
Since it is desirable that the wires 02 and 1103 be electrically connected well, they have a structure in which a part of each overlaps with the other. In the example of FIG.
Although the substrate, the device electrode, and the conductive thin film are stacked in this order from the bottom, in some cases, the substrate, the conductive thin film, and the device electrode may be stacked in this order from the bottom.

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

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

The thin film 1113 is made of any one of single crystal graphite, polycrystalline graphite, and amorphous carbon, or a mixture thereof, and has a thickness of 500 [Å] or less, but 300 [Å] or less. Is more preferred. The actual thin film 1113
It is difficult to accurately illustrate the position and shape of
Is schematically shown. In the plan view (A), 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 the embodiment, the following element is used.
That is, blue glass was used for the substrate 1101, and Ni thin films were used for the device electrodes 1102 and 1103. The thickness d of the device electrode is 1000 [angstrom], and the electrode interval L
Is 2 [micrometers].

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 description will be given of a method of manufacturing a suitable flat surface conduction electron-emitting device. FIGS. 14A to 14D
Is a cross-sectional view for explaining a manufacturing process of the surface conduction electron-emitting device, and the notation of each member is the same as in FIG.

(1) First, as shown in FIG.
Element electrodes 1102 and 1103 are formed over a substrate 1101. In forming these electrodes, the substrate 1101 is sufficiently washed beforehand with a detergent, pure water, and an organic solvent, and then the material of the device electrode is deposited (for example, a deposition method such as an evaporation method or a sputtering method). Vacuum film forming technology may be used). Thereafter, the deposited electrode material is patterned by using a photolithography / etching technique, and a pair of device electrodes (1102 and 1102) shown in FIG.
Form 3).

(2) Next, a conductive thin film 1104 is formed as shown in FIG. This conductive thin film 1104
In forming (1), first, an organic metal solution is applied to the substrate (a), dried, heated and baked to form a fine particle film, and then patterned into a predetermined shape by photolithography and etching. Here, the organic metal solution is a solution of an organic metal compound containing, as a main element, a material of fine particles used for a conductive thin film (specifically, in this embodiment, Pd was used as a main element. In the embodiment, a dipping method is used as a coating method.
Other than that, for example, a spinner method or a spray method may be used).

As a method of forming a conductive thin film made of a fine particle film, other than the method of applying an organic metal solution used in the present embodiment, for example, a vacuum evaporation method, a sputtering method, or a chemical vapor deposition method In some cases, a deposition method or the like is used.

(3) Next, as shown in FIG. 10C, the forming electrodes 1110 and 1112 are supplied from the forming power supply 1110.
The electron emitting portion 1105 is formed by applying an appropriate voltage during the period 03 and performing the energization forming process.

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

FIG. 15 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 the present 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 is
The pressure was increased sequentially. Also, monitor pulses Pm for monitoring the state of formation of the electron-emitting portion 1105 are inserted at appropriate intervals between the triangular-wave pulses, and the current flowing at that time is measured by the ammeter 1.
It was measured at 111.

In the present embodiment, for example, in a vacuum atmosphere of about 10 −5 [torr], for example, the pulse width T1 is set to 1 [millisecond], and the pulse interval T2 is set to 10
[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.
In order not to adversely affect the forming process,
The monitor pulse voltage Vpm was set to 0.1 [V].
Then, when the electric resistance between the element electrodes 1102 and 1103 becomes 1 × 10 6 [ohm], that is, when the current measured by the ammeter 1111 when the monitor pulse is applied becomes 1
At the stage where the power became × 10 −7 [A] or less, the energization related to the forming process was terminated.

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

(4) Next, as shown in FIG.
The device electrodes 1102 and 1103 are supplied from the activation power source 1112.
During the energization activation process, apply an appropriate voltage during
Improve electron emission characteristics. This energization activation process
This is a process of energizing the electron-emitting portion 1105 formed by the energization forming process under appropriate conditions to deposit carbon or a carbon compound in the vicinity thereof.
(In the figure, a deposit made of carbon or a carbon compound is schematically shown as a member 1113). Note that by performing the energization activation process, the emission current at the same applied voltage can be typically increased by 100 times or more as compared with before the energization activation process.

Specifically, 10 minus 4th power to 1
In a vacuum atmosphere in the range of 0 to the fifth power [torr],
By periodically applying a voltage pulse, carbon or a carbon compound originating from an organic compound existing in a vacuum atmosphere is deposited. The deposit 1113 is any one of single-crystal graphite, polycrystalline graphite, and amorphous carbon, or a mixture thereof, and has a thickness of 500 Å or less, more preferably 300 Å or less.

FIG. 16A shows an example of an appropriate voltage waveform applied from the activation power supply 1112 in order to describe the energization method in more detail. In the present embodiment, the energization activation process is performed by applying a rectangular wave of a constant voltage periodically, but specifically, the rectangular wave voltage Vac is 14
[V], pulse width T3 is 1 [millisecond], pulse interval T
4 is 10 [milliseconds]. The above-mentioned energization conditions are as follows:
This is a preferable condition 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 condition accordingly.

Reference numeral 1114 shown in FIG. 14D denotes an anode electrode for capturing the emission current Ie emitted from the surface conduction electron-emitting device, to which a DC high voltage power supply 1115 and an ammeter 1116 are connected. (Note that the substrate 1101
When the activation process is performed after the display panel is incorporated into the display panel, the phosphor screen of the display panel is connected to the anode electrode 1114.
Used as). 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 processing, and the activation power supply 111
2 is controlled. FIG. 16B shows an example of the emission current Ie measured by the ammeter 1116. Activation power supply 11
When the pulse voltage starts to be applied from 12, 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-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, the conditions should be changed accordingly. Is desirable.

As described above, the planar surface conduction electron-emitting device shown in FIG. 14E was manufactured.

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

FIG. 17 is a schematic cross-sectional view for explaining a vertical basic structure of the present embodiment.
01 is a substrate, 1202 and 1203 are device electrodes, 1206
Denotes a step forming member, 1204 denotes a conductive thin film using a fine particle film, 1205 denotes an electron emitting portion formed by an energization forming process, and 1213 denotes a thin film formed by an energization activation process.

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 FIG.
Is the step height L of the step forming member 1206 in the vertical type.
s. In addition, the substrate 1201, the element electrode 1
202 and 1203, conductive thin film 1 using fine particle film
204, the materials listed in the description of the planar type can be used in the same manner. For the step forming member 1206, an electrically insulating material such as SiO2 is used. The present invention is effective when such a vertical type has a potential distribution in a plane even when a step is present. In this case, the direction of the electric field due to the driving voltage is inclined as compared with the plane type due to the presence of the step. It is still possible to suppress the deviation of the beam by keeping the ratio of.
That is, the present embodiment is effective when an electric field having a component perpendicular to the direction of the acceleration voltage is generated.

Next, a method of manufacturing a vertical surface conduction electron-emitting device will be described. FIGS. 18A to 18F are cross-sectional views for explaining a manufacturing process.
Is the same as

(1) First, as shown in FIG.
An element electrode 1203 is formed over a substrate 1201.

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

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

4) Next, as shown in FIG. 11D, 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. 11E, a conductive thin film 1204 using a fine particle film is formed. For the formation, as in the case of the flat type, a film forming technique such as a coating method may be used.

6) Next, as in the case of the planar type, the energization forming process is performed to form an electron emission portion (the same process as the planar type energization forming process described with reference to FIG. 14C). Just do it.)

(7) Next, as in the case of the flat type,
An energization activation process is performed to deposit carbon or a carbon compound in the vicinity of the electron-emitting portion (the same process as the planar energization activation process described with reference to FIG. 14D may be performed).

As described above, the vertical surface conduction electron-emitting device shown in FIG. 18F was manufactured.

(Characteristics of Surface Conduction Emission Device Used in Display Device) The element structure and manufacturing method of the planar and vertical surface conduction electron-emitting devices have been described above. Next, the characteristics of the device used in the display device will be described. Is described.

FIG. 19 shows (emission current Ie) versus (element applied voltage Vf) characteristics of the element used in the display device of this embodiment.
And typical examples of (device current If) versus (device applied voltage Vf) characteristics. 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. For,
The two graphs are shown in arbitrary units.

The element used in the display device has the following three characteristics regarding the emission current Ie.

First, when a voltage higher than a certain voltage (hereinafter referred to as a threshold voltage Vth) is applied to the element, the emission current Ie sharply increases. On the other hand, when the voltage is lower than the threshold voltage Vth, the emission current Ie increases. Ie is hardly detected. That is, it is a non-linear element having 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 depends on the voltage Vf.
Size 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 for applying the voltage Vf. Can control.

Because of the above characteristics, the surface conduction electron-emitting device could be suitably used for a display device. For example, in a display device in which a large number of elements are provided corresponding to pixels of a display screen, if the first characteristic is used, display can be performed by sequentially scanning the display screen. That is,
The driving element has a threshold voltage Vth according to a desired light emission luminance.
The above voltage is appropriately applied, and a voltage lower than the threshold voltage Vth is applied to the non-selected elements. By sequentially switching the elements to be driven, the display screen can be sequentially scanned and displayed.

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 Source in which Many Devices are Wiring in a Simple Matrix) Next, the structure of a multi-electron source in which the above-described surface conduction electron-emitting devices are arranged on a substrate and wired in a simple matrix will be described.

FIG. 20 is a plan view of the multi-electron source used for the display panel 1000 shown in FIG. On the substrate 1001, surface conduction type emission elements similar to those shown in FIG. 13 are arranged, and these elements are wired in a simple matrix by row-direction wiring electrodes 1003 and column-direction wiring electrodes 1004. An insulating layer (not shown) is formed between the row-directional wiring electrodes 1003 and the column-directional wiring electrodes 1004 where they intersect, so that electrical insulation is maintained.

FIG. 21 shows a cross section taken along the line AA ′ of FIG.

The multi-electron source having such a structure is as follows.
After previously forming a row direction wiring electrode 1003, a column direction wiring electrode 1004, an interelectrode insulating layer (not shown), and a device electrode and a conductive thin film of a surface conduction electron-emitting device on a substrate,
Row direction wiring electrode 1003 and column direction wiring electrode 1004
The device was manufactured by supplying power to each element through the device and performing an energization forming process and an energization activation process.

FIG. 22 shows a configuration in which image information provided from various image information sources such as television broadcasting can be displayed on a display panel using the above-described surface conduction electron-emitting device as an electron source. It is a figure for showing an example of a multifunctional display device. In the figure, 1000 is the display panel described above, 2101 is a display panel driving circuit, 2102 is a display controller, 2103 is a multiplexer, 2104 is a decoder,
2105 is an input / output interface circuit, 2106 is C
PU 2107 is an image generation circuit, 2108 and 210
9 and 2110 are image memory interface circuits,
2111 is an image input interface circuit, 2112 and 2113 are TV signal receiving circuits, and 2114 is an input unit.

(Note that, when the present display device receives a signal containing both video information and audio information, such as a television signal, it naturally reproduces the audio simultaneously with the display of the video. Descriptions of circuits, speakers, and the like relating to reception, separation, reproduction, processing, storage, and the like of audio information that are not directly related to the features of the present invention will be omitted.) Hereinafter, the function of each unit will be described along the flow of image signals. go.

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

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

The image input interface circuit 21
Reference numeral 11 denotes a circuit for capturing an image signal supplied from an image input device such as a TV camera or an image reading scanner. The captured image signal is output to a decoder 2104.

The image memory interface circuit 2
110 is a video tape recorder (hereinafter abbreviated as VTR)
Is a circuit for capturing the image signal stored in the decoder 2104. The captured image signal is output to the decoder 2104.

The image memory interface circuit 2
Reference numeral 109 denotes a circuit for capturing an image signal stored in the video disk, and the captured image signal is output to the decoder 2104.

The image memory interface circuit 2
Reference numeral 108 denotes a circuit for taking in an image signal from a device that stores still image data, such as a so-called still image disk.
04 is output.

The input / output interface circuit 210
Reference numeral 5 denotes a circuit for connecting the present display device to an external computer, a computer network, or an output device such as a printer. In addition to inputting and outputting image data, character data, and graphic information, control signals and numerical data can be input and output between the CPU 2106 included in the display device and the outside in some cases. .

Further, the image generation circuit 2107 is provided with image data, character / graphic information input from the outside via the input / output interface circuit 2105, or a CPU.
A circuit for generating display image data based on the image data and character / graphic information output from 2106.
Within this circuit, for example, a rewritable memory for storing image data and character / graphic information, a read-only memory for storing image patterns corresponding to character codes, and a processor for performing image processing Circuits necessary for generating an image, such as those described above, are incorporated. The display image data generated by this circuit is
The data is output to an external computer network or a printer via the input / output interface circuit 2105 in some cases.

The CPU 2106 mainly performs operations related to operation control of the display device and generation, selection, and editing of a display image.

For example, a control signal is output to the multiplexer 2103, and an image signal to be displayed on the display panel is appropriately selected or combined. In this case, a control signal is generated for the display panel controller 2102 in accordance with an image signal to be displayed, and a display frequency, a scanning method (for example, interlaced or non-interlaced), and the number of scanning lines per screen are displayed. The operation of the device is appropriately controlled.

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

The CPU 2106 may, of course, be involved in work for other purposes. For example,
It may be directly related to a function of generating and processing information, such as a personal computer or a word processor.

Alternatively, the computer may be connected to an external computer network via the input / output interface circuit 2105 as described above, and operations such as numerical calculations may be performed in cooperation with external devices.

The input unit 2114 is connected to the CPU 21.
06 is for the user to input commands, programs, data, and the like. For example, in addition to a keyboard and a mouse, various input devices such as a joystick, a barcode reader, and a voice recognition device can be used.

Also, the decoder 2104 has the
And 2113 are circuits for inversely converting various image signals inputted from 2113 into three primary color signals or luminance signals and I and Q signals. It is to be noted that the decoder 2104 desirably includes an image memory therein, as indicated by a dotted line in FIG. This is for handling television signals that require an image memory when performing inverse conversion, such as the MUSE method. Further, the provision of the image memory facilitates the display of a still image, or enables 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 there is an advantage that it can be easily performed.

The multiplexer 2103 is connected to the C
A display image is appropriately selected based on a control signal input from the PU 2106. That is, the multiplexer 2103 selects a desired image signal from the inversely converted image signals input from the decoder 2104 and outputs the selected image signal to the drive circuit 2101. In that case, by switching and selecting an image signal within one screen display time, it is possible to divide one screen into a plurality of areas and display different images depending on the areas, as in a so-called multi-screen TV. .

The display panel controller 2
Reference numeral 102 denotes a circuit for controlling the operation of the drive circuit 2101 based on a control signal input from the CPU 2106.

First, as a signal related to the basic operation of the display panel, for example, a signal for controlling an operation sequence of a power supply (not shown) for driving the display panel is output to the driving circuit 2101. In addition, a signal for controlling, for example, a screen display frequency and a scanning method (for example, interlaced or non-interlaced), which is related to the display panel driving method, is output to the driving circuit 2101.

In some cases, a control signal relating 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 is a circuit for generating a drive signal to be applied to the display panel 1000. The drive circuit 2101 is a circuit for generating an image signal input from the multiplexer 2103 and the display panel controller 21.
02 operates based on a control signal input from the control unit 02.

The function of each section has been described above. With the configuration illustrated in FIG. 22, in this display device, image information input from various image information sources is displayed on the display panel 1.
000 can be displayed. That is, various image signals including television broadcasting are transmitted to the decoder 21.
After the inverse conversion at 04, the multiplexer 2103
And is input to the driving circuit 2101 as appropriate. On the other hand, the display controller 2102 generates a control signal for controlling the operation of the drive circuit 2101 according to the image signal to be displayed. The drive circuit 2101 controls the display panel 1 based on the image signal and the control signal.
000 is applied to the drive signal. Thus, an image is displayed on display panel 1000. These series of operations are totally controlled by the CPU 2106.

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

Therefore, the present display device is a television broadcast display device, a video conference terminal device, an image editing device that handles still and moving images, a computer terminal device, an office terminal device such as a word processor,
It can be equipped with the functions of a game machine etc. by one unit, and has a very wide application range for industrial or consumer use.

FIG. 22 shows only an example of the configuration of a display device using a display panel using a surface conduction electron-emitting device as an electron source, and it is needless to say that the present invention is not limited to this. No. For example, among the components shown in FIG. 22, circuits relating to functions that are not necessary for the purpose of use may be omitted. Conversely, additional components may be added depending on the purpose of use. For example, when the present display device is applied as a video phone, it is preferable to add a transmission / reception circuit including a television camera, an audio microphone, an illuminator, and a modem to the components.

In the present display device, in particular, a display panel using a surface conduction electron-emitting device as an electron source can be easily thinned, so that the depth of the entire display device can be reduced. In addition, since the display panel using the surface conduction electron-emitting device as the electron source is easy to enlarge the screen, has high brightness, and has excellent viewing angle characteristics, this display device is capable of displaying images full of immersion and full of powerful images with good visibility. It is possible to display.

As described above, according to the present embodiment, in an image display apparatus using a surface conduction electron-emitting device and a horizontal field emission device as an electron source, a color shift and a luminance step are eliminated, and a display panel is manufactured. It became possible to suppress the light emission luminance.

Further, according to the present embodiment, the average luminance of the image display device can be suppressed to a certain reference value or less, whereby the power consumption of the image display device and the heat generation in the fluorescent plate can be suppressed.

Further, in the present embodiment, by controlling the overall light emission luminance based on the average luminance, for example, even in the case of an image in which the luminance of the main object in the center of the image is high and the luminance of the periphery thereof is low, Good display can be performed without lowering the luminance of the main object.

[0160]

As described above, according to the present invention, it is possible to minimize the shift of the arrival position of the electrons emitted from the cold cathode devices while suppressing the light emission luminance in the image forming panel.

According to the present invention, when the light emission luminance is equal to or more than the predetermined value, the power consumption and the heat generation of the image forming panel are reduced by changing the device voltage applied to the device and the acceleration voltage for accelerating electrons. There is an effect that it can be suppressed.

Further, according to the present invention, there is an effect that color misregistration of a formed image can be suppressed, and power consumption and heat generation can be suppressed.

[0163]

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an image display device according to an embodiment of the present invention.

FIG. 2 is a timing chart showing vertical drive timing of the display panel of the present embodiment.

FIG. 3 is a timing chart showing horizontal drive timing of the display panel of the present embodiment.

FIG. 4 is a block diagram illustrating a configuration of a system control unit according to the present embodiment.

FIG. 5 is a block diagram illustrating a configuration of a luminance adjustment unit according to the present embodiment.

FIG. 6 is a flowchart illustrating a control operation of a system control unit according to the present embodiment.

7A and 7B are a cross-sectional view and a plan view, respectively, for defining the direction of the surface conduction electron-emitting device.

FIG. 8 is a perspective view showing a typical horizontal field emission device.

9A and 9B are a cross-sectional view and a plan view, respectively, for defining a horizontal field emission device direction.

FIG. 10 shows a voltage Vf applied to the electron-emitting device and an acceleration voltage Va.
FIG. 9 is a graph showing relative luminance when the element voltage Vf is changed linearly while keeping the ratio of the constant.

FIG. 11 is a perspective view of a display panel of the image display device according to the present embodiment, with a part of the display panel being cut away.

FIG. 12 is a plan view illustrating a phosphor array of a face plate of the display panel of the present embodiment.

FIGS. 13A and 13B are a plan view and a cross-sectional view, respectively, of the planar type surface conduction electron-emitting device used in the present embodiment.

FIG. 14 is a cross-sectional view showing a step of manufacturing the planar surface conduction electron-emitting device of the present embodiment.

FIG. 15 is a diagram showing an applied voltage waveform during the energization forming process.

FIG. 16 shows an applied voltage waveform (a) in the energization activation process;
It is a figure showing change (b) of emission current Ie.

FIG. 17 is a sectional view of a vertical surface conduction electron-emitting device used in the present embodiment.

FIG. 18 is a cross-sectional view showing a manufacturing process of the vertical surface conduction electron-emitting device.

FIG. 19 is a graph showing typical characteristics of the surface conduction electron-emitting device used in the present embodiment.

FIG. 20 is a partial plan view of a substrate of the multi-electron source used in the present embodiment.

21 is a cross-sectional view of the substrate of the multi-electron source of FIG. 20 taken along the line AA ′ used in the present embodiment.

FIG. 22 is a block diagram of a multi-function image display device using the image display device according to the embodiment of the present invention.

FIG. 23 is a view showing an example of a conventionally known surface conduction electron-emitting device.

FIG. 24 is a diagram showing an example of a conventionally known FE-type element.

FIG. 25 is a diagram showing an example of a conventionally known MIM type device.

FIG. 26 is a diagram illustrating a simple matrix wiring.

27A and 27B are a cross-sectional view and a plan view, respectively, showing the trajectories of electrons emitted from the electron-emitting device.

FIG. 28 is a schematic diagram for illustrating a direction in which an electron-emitting device is formed.

[Explanation of symbols]

 61, 1000 Display panel 62 Decoder section 63 Analog preprocessing section 64a to 64c A / D converter section 65 Timing control section 66 Digital processing section 67 Data rearrangement section 73 Video detection section 74 System control section 75 Vf control section 77 High voltage generation section 78 Brightness adjuster

Claims (14)

[Claims] 1. An image forming apparatus having an image forming panel on which electron-emitting devices are arranged, comprising: a driving voltage generating means for generating a driving voltage for driving each of the electron-emitting devices; Acceleration voltage generation means for generating an acceleration voltage for accelerating electrons, brightness detection means for detecting the brightness of an image displayed on the display panel based on the input image signal, and detection by the brightness detection means. A control unit that controls the drive voltage generation unit and the acceleration voltage generation unit such that a ratio between the drive voltage and the acceleration voltage is substantially the same based on the brightness. Forming equipment. 2. The image forming apparatus according to claim 1, wherein the control unit compares the luminance detected by the luminance detection unit with a reference value, and when the luminance exceeds the reference value. The driving voltage and the acceleration voltage are changed. 3. The image forming apparatus according to claim 2, wherein the control unit controls the driving voltage and the acceleration voltage at an address corresponding to the luminance detected by the luminance detecting unit. It is characterized by further comprising storage means for storing control data. 4. The image forming apparatus according to claim 1, wherein said luminance detecting means includes an average value calculating means for calculating an average value of luminance levels of the input image signal, and Is output as a luminance value. 5. The image forming apparatus according to claim 1, further comprising current value detecting means for detecting a value of a current flowing by an acceleration voltage generated by said acceleration voltage generating means, wherein said control means is configured to control said control means. The driving voltage generating means and the accelerating voltage generating means are controlled based on an average current value. 6. The image forming apparatus according to claim 1, further comprising current detection means for detecting a current value supplied to said acceleration voltage generation means, wherein said control means controls said supplied current value. The driving voltage generating means and the acceleration voltage generating means are controlled based on the following. 7. The image forming apparatus according to claim 1, wherein said electron-emitting device is a surface conduction type electron-emitting device. 8. An image forming method for forming an image on an image forming panel on which a plurality of electron-emitting devices are arranged, comprising: detecting a luminance of an image displayed on the display panel based on an input image signal. And a control step of controlling the values of the drive voltage and the acceleration voltage to be changed so that the ratio between the drive voltage and the acceleration voltage is substantially the same based on the luminance detected in the luminance detection step. An image forming method comprising: 9. The image forming method according to claim 8, wherein in the controlling step, the luminance detected in the luminance detecting step is compared with a reference value, and when the luminance exceeds the reference value. The driving voltage and the acceleration voltage are changed. 10. The image forming method according to claim 9, wherein in the control step, the driving voltage and the acceleration voltage are controlled at an address corresponding to the luminance detected in the luminance detecting step. A memory for storing control data is accessed to extract data for controlling the drive voltage and the acceleration voltage. 11. The image forming method according to claim 8, wherein the luminance detecting step includes an average value calculating step of calculating an average value of luminance levels of the input image signal,
The average value is output as a luminance value. 12. The image forming method according to claim 8, further comprising a current value detecting step of detecting a current value flowing by said acceleration voltage, wherein said controlling step is based on an average value of said current values. The driving voltage and the acceleration voltage are changed. 13. The image forming method according to claim 8, further comprising a current detecting step of detecting a current value supplied to generate the acceleration voltage, wherein the controlling step includes:
The driving voltage and the acceleration voltage are changed based on the supplied current value. 14. An image forming method according to claim 8, wherein said electron-emitting device is a surface-conduction electron-emitting device.