JPH11288246A - Picture display device and display control method for the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the luminance of a picture displayed on a display panel without changing the value of an inputted video signal (picture signal). SOLUTION: The inputted video signal is converted into a digital signal to generate a one-line portion of picture data, and a column wiring of a display panel 14 is driven by an analog signal having the amplitude corresponding to this picture data. Synchronously with this driving, a row wiring of the display panel 14 to be driven for scanning is selected by a vertical shift register 9, and a signal having the pulse width indicated by a luminance adjustment part 6 is applied to this selected row wiring. Since this luminance adjustment part 6 drives a PWM pulse generation part 8 so as to generate the signal having the pulse width corresponding to the luminance value indicated by a user, the pulse signal which has the pulse width corresponding to the value of the inputted picture signal and has the time width corresponding to the designated luminance is applied to each electron emitting element of the display panel 14, and thus, the quantity of electrons emitted from each element is controlled to adjust the luminance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image display device provided with a display panel having a plurality of electron-emitting devices and a display control method in the image display device.

[0002]

2. Description of the Related Art In recent years, research and development of thin and large screen display devices have been actively conducted. The present inventor has been conducting research using a cold cathode as an electron source as a thin large-screen display device.

Conventionally, two types of electron-emitting devices, a hot cathode device and a cold cathode device, are known. Among these, among the cold cathode devices, for example, a surface conduction type emission device, a field emission type device (hereinafter referred to as FE type), a metal / insulating layer / metal type emission device (hereinafter referred to as MIM type), and the like are known. I have.

[0004] As the surface conduction type emission element, for example, M.
I. Elinson, Radio E-ng. Electron Phys., 10, 1290,
(1965) and other examples described later.

[0005] The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. 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)].

FIG. 17 shows a plan view of a device by M. Hartwell et al. As a typical example of the device configuration of these surface conduction electron-emitting devices. 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, such as the device by M. Hartwell et al., Before the electron emission, an electron emission portion 3005 is formed by subjecting the conductive thin film 3004 to an energization process called energization forming. Was common. That is, energization forming is
A constant DC voltage or a DC voltage which is boosted at a very slow rate of, for example, about 1 V / min is applied to both ends of the conductive thin film 3004 to conduct electricity.
004 is locally destroyed, deformed, or altered to form an electron emitting portion 3005 in an electrically high-resistance state. 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.

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

As 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 this FE type device configuration, FIG. 18 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.

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. 19 shows a typical example of the 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-described 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 applications of the surface conduction electron-emitting device, for example, image forming apparatuses such as image display apparatuses and image recording apparatuses, and charged beam sources have been studied.

Particularly, as an application to an image display device, for example, as disclosed in US Pat. No. 5,066,883, 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 attempted surface conduction type emission devices having various materials, manufacturing methods and structures, including those described in the above-mentioned prior art. Further, research has been conducted on a multi-electron source in which a large number of surface conduction electron-emitting devices are arranged, and on an image display device using the multi-electron source. For example, a multi-electron source based on the electrical wiring method shown in FIG. 20 has been tried. That is, the surface conduction type emission device is
This is a multi-electron source in which a large number of elements are arranged in a dimension, and these elements are wired in a matrix as shown in the figure.

In the figure, 4001 schematically shows a surface conduction electron-emitting device, 4002 shows a row direction wiring, and 4003 shows a column direction wiring. Although the row direction wiring 4002 and the column direction wiring 4003 actually have a finite electric resistance, they are shown as wiring resistances 4004 and 4005 in the figure. The above-described wiring method is called simple matrix wiring. Although a 6 × 6 matrix is shown for convenience of illustration, the size of the matrix is not limited to this. For example, in the case of a multi-electron source for displaying images, a desired image is displayed. Only enough elements are arranged and wired.

In the multi-electron source in which the surface conduction electron-emitting devices are arranged in a simple matrix as described above, 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 any one of the surface conduction electron-emitting devices 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 40 of the non-selected row is applied.
02 is applied with a non-selection voltage Vns. In synchronization with this, a drive voltage Ve for outputting an electron beam is applied to the column wiring 4003. According to this method, the wiring resistance 40
Neglecting the voltage effects of the elements 04 and 4005, a voltage of (Ve−Vs) is applied to the surface conduction type emission elements of the selected row, and (V) is applied to the surface conduction type emission elements of the non-selected rows.
e-Vns). Where Ve, Vs,
If Vns is set to a voltage of an appropriate magnitude, an electron beam having a desired intensity should be output only from the surface conduction electron-emitting device of the selected row, and a different drive voltage Ve is applied to each of the column-directional wirings. Then, the electron beams of different intensities should be output from each of the elements in the selected row. In addition, since the response speed of the surface conduction electron-emitting device is high,
If the length of time during which the drive voltage Ve is applied is changed, the length of time during which the electron beam is output should be changed.

Hereinafter, the element applied voltage (Ve-V
s) is called Vf.

Further, as another method for obtaining an electron beam from the multi-electron source wired in a simple matrix as described above, a drive current is supplied instead of connecting a voltage source for applying a drive voltage Ve to a column wiring. And a selection voltage Vs in the row direction wiring of the row to be selected.
, And simultaneously applying a non-selection voltage Vns to the row direction wirings of the non-selected rows. This allows
Due to the strong threshold characteristic of the surface conduction electron-emitting device, an electron beam can be obtained only from the device in the selected row.
Here, the current flowing through the electron source is hereinafter referred to as an element current If, and the emitted electron beam current is referred to as an emission current Ie.

Therefore, a multi-electron source having a surface conduction type electron-emitting device arranged in a simple matrix has various applications. For example, if an electric signal corresponding to image information is appropriately applied, the multi-electron source can be used as an electron source for an image display device. It can be suitably used.

[0024]

However, a multi-electron source in which surface conduction electron-emitting devices are arranged in a simple matrix has actually caused the following problems.
It is desired that the so-called image display device can adjust the brightness of the display image according to the preference of each user and the brightness of the surroundings where the image display device is installed. Conventionally, in such an image display device, the video signal amplitude level has been controlled in order to perform luminance adjustment.

In this case, since the video signal level also serves as the gradation expression of the display image, there is a problem that if the luminance adjustment is performed to lower the emission luminance, the number of gradations of the display image will also change. Was. In particular, when the brightness is adjusted in the darkening direction, the number of gradations of the displayed image is reduced, and the image quality is deteriorated.

Further, the image display device sometimes controls the average luminance of the display panel so as not to exceed a certain level in order to suppress the power consumption of the device and the rise in temperature of the light emitting surface.
Conventionally, in such an image display device, the amplitude level of the video signal has been controlled in order to perform the luminance control. However, when such brightness control is performed, there is a problem that the number of gradations of a display image also changes.

The present invention has been made in view of the above conventional example, and has as its object to provide an image display device capable of adjusting the luminance to be displayed without changing the value of an image signal, and a display control method in the device. And

It is another object of the present invention to provide an image display apparatus and a display control method in the apparatus which can adjust the luminance so as to obtain the designated luminance without changing the value of an input image signal.

Another object of the present invention is to provide an image display apparatus and a display control method in the apparatus which can suppress the emission luminance without changing the image signal when the average luminance of the input image signal is high. Is to do.

Another object of the present invention is to provide an image display apparatus and a display control method in the apparatus which can adjust the light emission luminance of a display panel without changing an image signal in accordance with an environment where the apparatus is placed or a user's specification. Is to provide.

[0031]

In order to achieve the above object, an image display device according to the present invention has the following arrangement.
That is, a display panel in which a plurality of electron-emitting devices are arranged and provided with a light-emitting body that emits light by electrons emitted from the electron-emitting devices, and a driving unit that drives the plurality of electron-emitting devices in accordance with an input image signal. An instructing means for instructing light emission luminance in the display panel; and a controlling means for controlling a driving time for driving the electron-emitting device in synchronization with driving by the driving means based on an instruction from the instructing means. It is characterized by.

To achieve the above object, the display control method of the present invention comprises the following steps. That is, a display control method for an image display device having a display panel in which a plurality of electron-emitting devices are arranged and a light-emitting body emits light by electrons emitted from the electron-emitting devices, and the method according to an input image signal A driving step of driving the plurality of electron-emitting devices; an instruction step of instructing light emission luminance in the display panel; and driving the electron-emitting elements in synchronization with the driving of the driving step based on the instruction in the instruction step. And a control step of controlling the driving time.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, an example of a display panel having elements arranged in a matrix will be described. However, the present invention can be applied to a case of an element arrangement such as a linear type or a ladder type.

[Embodiment 1] FIG. 1 is a block diagram showing a configuration of an image display apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram showing timing waveforms of signals of respective parts in FIG.

In FIG. 1, reference numeral 14 denotes a display panel,
Elements (cold cathode elements) wired in a matrix of n are provided. Reference numeral 1 denotes a video signal input terminal for inputting a video signal. Reference numeral 2 denotes an analog processing unit, which converts a video signal into a digital signal with a necessary number of gradations in an A / D conversion unit 3 in a subsequent stage. And so on. Reference numeral 4 denotes a synchronization separation unit which converts a video signal into a synchronization signal (horizontal,
Vertical synchronizing signal and pixel clock). 5
Is a timing generator, which inputs the synchronization signal separated by the synchronization separator 4 and supplies necessary timing signals to the A / D unit 3 and other units. The user I / F 7 functions as an operation unit for the user of the image display device of the present embodiment to perform brightness adjustment, and a signal input from the user interface (I / F) 7 is used as a brightness adjustment unit. 6 and becomes information for increasing or decreasing the display luminance on the display panel 14. The brightness adjustment unit 6 converts the brightness increase / decrease signal input from the user interface 7 into a pulse width control signal to the PWM pulse generation unit 8 and outputs the signal. The PWM pulse generator 8 includes, for example, a down counter and a flip-flop circuit, and the pulse width control signal from the luminance adjuster 6 is set in the down counter. When a horizontal trigger signal and a clock signal are input from the timing generator 5, the down counter starts counting down using the horizontal trigger signal. Then, the timing at which the counter value of the down counter becomes zero “0” is
When the flip-flop circuit receives the horizontal trigger signal, a PWM pulse having a pulse width corresponding to the above-described pulse width control signal is output.

The vertical shift register 9 receives a vertical trigger signal and a horizontal synchronizing signal from the timing generator 5 and outputs a selection signal (constant amplitude) having a predetermined pulse width for selecting a scan line to be displayed on the display panel 14. Occur. The scanning line driving unit 13 receives the selection signal from the vertical shift register 9 and the PWM pulse from the PWM pulse generation unit 8,
The AND circuit 130 takes the logical product of them and switches the switch circuit 1131. Switch circuit 131
Outputs the voltage from the voltage source 132 (Vs) to the corresponding row wiring (scanning line) while the output of the AND circuit 130 is at the high level. The selected scanning line has a pulse width V determined by the PWM pulse generator 8 and a peak value V
A bias voltage of s (constant) is applied, and other unselected scan lines are connected to the GND level.

The A / D unit 3 converts the video analog signal processed by the analog processing unit 2 into a serial digital signal for n pixels per horizontal period, and
Output to 0. This serial signal is converted to a parallel signal by the horizontal shift register unit 10 and then sent to the one-line memory 11 and held. The D / A unit 12 includes n D / A converters of the same number as the number of column wirings of the display panel 14, and converts each of the n pixels of parallel data input from the one-line memory 11 into each D / A converter. The A-converter receives and applies a voltage or current having the same pulse width and the amplitude corresponding to each pixel data output from the one-line memory to all the column wirings at the same time.

In FIG. 2, reference numeral 201 denotes a waveform example of an input video signal, 202 denotes a signal obtained by converting the video signal into a digital signal by the A / D unit 3, and 203 denotes a D / D signal.
3 shows an output signal of the A section 12. This output signal has the same pulse width for each column wiring, and its amplitude is changed according to the digital value input from the one-line memory 11. Reference numeral 204 denotes an output signal of the vertical shift register 9,
A selection signal for sequentially selecting each scanning line is output in synchronization with a horizontal synchronization signal included in the video signal. 20
Reference numeral 5 denotes an output signal of the PWM pulse generation unit 8, and the pulse width of the pulse signal output from the PWM pulse generation unit 8 is a pulse width corresponding to the luminance set by the user interface 7. Reference numeral 206 denotes an output signal of the scanning line driving unit 13, and is applied to a row wiring selected by the vertical shift register 9.
A row drive signal corresponding to the pulse width output from the PWM pulse generator 8 is output.

In the above configuration, a digital signal corresponding to the amplitude signal of the video signal is obtained by the A / D section 3, and a drive voltage or a drive current corresponding to the number of gradations of the digital signal is applied to the column wiring of the display panel 14. Is applied to

On the other hand, a bias voltage having a pulse width corresponding to the luminance adjusted by the user of the image display device is applied to the selected scanning line in the row wiring of the display panel 14. That is, the brightness of the image display device can be adjusted without changing the number of gradations of the video signal.

[Second Embodiment] FIG. 3 is a block diagram showing a configuration of an image display apparatus according to a second embodiment of the present invention. Portions common to those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. I do.

In the figure, reference numeral 15 denotes an average value detection unit which detects the average luminance of an input video signal. An external light sensor 16 detects the brightness around the place where the image display device is installed. Reference numeral 17 denotes a table memory, which stores correction information for giving non-linearity to the gradation characteristics of the video signal. Further, the display panel 14 includes a plurality of surface conduction type emission elements wired in a matrix, and these emission elements have characteristics represented by an element voltage Vf (or If) and an emission current Ie shown in FIG. Have. Where D
The / A section 12 applies to the column wiring a drive voltage amplitude-modulated between a threshold voltage Vth at which the emission current Ie determined from the characteristics of FIG. 13 is generated and a voltage at which the emission current Ie has a maximum value from the threshold voltage Vth.
As described above, the video signal is corrected by the table memory 17 so that the gradation-light emission characteristic becomes substantially equal to, for example, the γ characteristic of the CRT.

Although an example in which a drive voltage is applied to the column wiring of the display panel 14 has been described here, the same applies when a drive current is applied.

The brightness adjusting section 6 has, for example, a microprocessor, an A / D converter, a memory, etc., and outputs the average level input value of the video signal from the average value detecting section 15 according to a program stored in the memory. The external light value input from the optical sensor 16 and the brightness adjustment value from the user I / F 7 are converted into digital values, and adaptively determined so as to be the brightness to be controlled, and the down counter of the PWM pulse generator 8 The pulse width data to be set is output. Thereby, the pulse width output from the PWM pulse generator 8 is controlled, and the time during which the drive voltage from the column wiring is applied to each surface conduction electron-emitting device of the display panel 14 is changed. Adjust the brightness (luminance).
The operation timing of each unit in the image display device according to the second embodiment is substantially the same as the case shown in FIG.

FIG. 4 is a flowchart showing the processing in the brightness adjusting section 6 according to the second embodiment.

First, in step S1, the average luminance of the input video signal is input from the average value detection unit 15. Next, proceeding to step S2, the ratio of the input average luminance to the maximum luminance included in the video signal, that is, (average luminance) /
(Maximum luminance) is obtained, and the value is set as an evaluation value (H1).
Next, the process proceeds to step S3, where the evaluation value (H1) is compared with a predetermined reference value. When the evaluation value (H1) is larger than the reference value, the process proceeds to step S4, where P = Pmax ×
By calculating H1, the pulse width output from the PWM pulse generator 8 is determined to be smaller than the maximum pulse width of PWM.

On the other hand, if the evaluation value (H1) is smaller than the reference value in step S3, the process proceeds to step S5, where the luminance value set on the user interface 7 and the external light value detected by the external light sensor 16 are determined. input. Next, the process proceeds to step S6, where the evaluation value (H2) is obtained by the following equation based on the user setting value and the external light value input in step S5.

H2 = ｛A × (user-set luminance value) + B ×
(External light value) + C｝ / H2max Here, each of A, B, and C is a weighting constant, H2ma
x is the maximum value that H2 can take.

Next, proceeding to step S7, the pulse width output from the PWM pulse generator 8 is determined by P = Pmax × H2 based on the evaluation value (H2) obtained in step S6. As a result, the evaluation value (H2) increases according to the external light value and the set luminance value, and as a result, the pulse width for driving each row wiring is set to be long (high luminance).

In this way, the flow advances to step S8 to check whether or not the PWM data (P) has changed. If the PWM data (P) has changed, the flow advances to step S9 to change the value of P from the original value (old value) to the updated value (new value). ), But if it is changed at a stretch, the change in brightness is noticeable. Therefore, the pulse width is changed while complementing the values.

As described above, in the first and second embodiments,
A signal having an amplitude corresponding to the value of the image signal and having a predetermined pulse width is applied to the column wiring of the display panel 14, and the designated emission luminance and / or the designated scanning luminance (row wiring) are displayed on the scanning line (row wiring) for displaying the image. Applies a signal having a pulse width and a predetermined amplitude so as to have emission luminance adjusted according to external light or the like. Thus, each element is driven by a signal having an amplitude corresponding to the value of the image signal, and the light emission luminance is controlled by the width of the pulse signal applied to the row wiring.

As described above, according to the second embodiment, the light emission luminance of the display panel can be controlled in accordance with the average luminance of the input video signal, and the luminance set by the user or the apparatus is installed. It is possible to adjust the light emission luminance according to the external light depending on the environment without changing the gradation of the video signal.

[Structure of display panel and manufacturing method thereof]
The configuration and manufacturing method of the display panel 14 used in the image display device according to the embodiment of the present invention will be described with reference to specific examples.

FIG. 5 is a perspective view of the display panel used in the present embodiment, in which a part of the display panel 14 is cut away to show the internal structure.

In the figure, 1005 is a rear plate, 1006
Is a side wall, 1007 is a face plate, 1005
1007 form an airtight container for maintaining the inside of the display panel at a vacuum. When assembling this hermetic container, it is necessary to seal the joints of each member to maintain sufficient strength and airtightness.For example, frit glass is applied to the joints, and in the air or in a nitrogen atmosphere, Sealing was achieved by baking at 400 ° C. to 500 ° C. for 10 minutes or more. 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, and 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 a number of 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 103
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 this embodiment, 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 a 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 phosphors of each color are separately applied in stripes as shown in FIG. 6A, for example, and black conductors 1010 are provided between the stripes of the phosphors of each color. 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. 6 shows how to paint the three primary color phosphors.
The arrangement is not limited to the stripe arrangement shown in FIG. 6A, but may be, for example, a delta arrangement as shown in FIG.
Other arrangements may be used. 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 field of CRTs is provided on the surface of the fluorescent film 1008 on the rear plate side.
Is provided. The purpose of providing the metal back 1009 is to improve the light utilization rate by mirror-reflecting a part of the light emitted from the fluorescent film 1008 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 airtight seals provided for electrically connecting the display panel 14 to the electric circuits such as the D / A unit 12 and the scanning line driving unit 13. It is a terminal for electrical connection having a structure. The row direction terminals Dx1 to Dxm are the row direction wirings 1003 of the multi-electron source.
The column direction terminals Dy1 to Dyn are electrically connected to the column direction wiring 1004 of the multi-electron source, and Hv is further electrically connected to the metal back 1009 of the face plate.

In order to evacuate the inside of the hermetic container to a vacuum, after assembling the hermetic container, an exhaust pipe (not shown) and a vacuum pump are connected, and the inside of the hermetic container is about 10 −7 [torr]. Evacuate to vacuum. Thereafter, the exhaust pipe is sealed, but a getter film (not shown) is formed at a predetermined position in the airtight container immediately before or after the sealing in order to maintain the degree of vacuum in the airtight container. The getter film is, for example, a film formed by heating and depositing a getter material containing Ba as a main component by a heater or high-frequency heating, and the inside of the hermetic container is 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
The basic configuration and manufacturing method of No. 4 have been described.

Next, a method for manufacturing a multi-electron source used for the display panel 14 of this embodiment will be described. The material, shape, and manufacturing method of the cold cathode device are not limited as long as the multi-electron source used in the image display device of the present embodiment is an electron source in which the cold cathode devices are arranged in a simple matrix. Therefore, for example, a surface conduction type emission element, an FE type, or an MI
A cold cathode device such as an M type can be used.

However, in a situation where a display device having a large display screen and an inexpensive display device is required, among these cold cathode devices, a surface conduction type emission device is particularly preferable. That is, F
Since the relative position and shape of the emitter cone and the gate electrode greatly affect the electron emission characteristics in the E type, extremely high-precision manufacturing technology is required, which is disadvantageous in achieving a large area and a reduction in manufacturing cost. Factors. Also, MIM
In the mold, the thicknesses of the insulating layer and the upper electrode need to be thin and uniform, which is also a disadvantageous factor in achieving a large area and a reduction in manufacturing cost. In this regard, since the surface conduction electron-emitting device has a relatively simple manufacturing method, it is easy to increase the area and reduce the manufacturing cost.

The present inventors have found that among the surface conduction electron-emitting devices, those in which the electron-emitting portion or its peripheral portion is formed of a fine particle film have particularly excellent electron-emitting characteristics and can be easily manufactured. ing. 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 14 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 configuration, manufacturing method, and characteristics of a suitable surface conduction electron-emitting device will be described first, and then the structure of a multi-electron source in which a large number of surface conduction electron-emitting devices are arranged in a simple matrix will be described.

(Suitable Device Configuration and Manufacturing Method of Surface Conduction Type Emission Device) There are two typical types of surface conduction type emission devices in which the electron emission portion or its peripheral portion is formed of a fine particle film, a flat type and a vertical type. Is raised.

(Flat-Type Surface-Conduction-Type Emission Element) First, the element configuration and manufacturing method of a flat-type surface-conduction-type emission element will be described.

FIGS. 7A and 7B are a plan view and a sectional view, respectively, for explaining the structure of a planar surface conduction electron-emitting device.

In the figure, 1101 is a substrate, 1102 and 110
Reference numeral 3 denotes an element electrode; 1104, a conductive thin film; 1105, an electron-emitting portion formed by an energization forming process;
Is 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.

Further, a fine particle film is used for the portion of 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.

Materials that can be used to form the fine particle film include, for example, 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. 7, the overlapping manner is such that the substrate, the device electrode, and the conductive thin film are stacked in this order from the bottom, but in some cases, the substrate, the conductive thin film, and the device electrode are stacked in this order from the bottom. I can't wait.

The electron-emitting portion 1105 is a crack-like portion formed in a part of the conductive thin film 1104, and has a higher electrical property than the surrounding conductive thin film. The crack is formed by performing a later-described energization forming process on the conductive thin film 1104. Fine particles having a particle size of several Angstroms to several hundred Angstroms may be arranged in the crack. Since it is difficult to accurately and accurately show the actual position and shape of the electron-emitting portion, they are schematically shown in 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
Since it is difficult to precisely illustrate the position and the shape of, they are schematically shown in FIG. 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 the 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. 8A to 8D are cross-sectional views for explaining a manufacturing process of the surface conduction electron-emitting device according to the present embodiment, and the notations of each member are the same as those in FIG.

(1) First, as shown in FIG. 8A, device electrodes 1102 and 1103 are formed on a substrate 1101. Before forming these electrodes, the substrate 1
After sufficiently washing 101 with a detergent, pure water and an organic solvent,
The material for the device electrode is deposited (as a deposition method,
For example, a vacuum film forming technique such as an evaporation method or a sputtering method may be used). After that, the deposited electrode material is patterned using photolithography and etching technology,
A pair of device electrodes (1102 and 1103) shown in FIG.
To form

(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. 9C, the forming power supply 1110 supplies the device electrodes 1102 and
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 to break, deform, or alter a part of the conductive thin film 1104 as appropriate 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. 9 shows an example of an appropriate voltage waveform applied from the forming power supply 1110 to explain the energization method in more detail. When forming a conductive thin film made of a fine particle film, a pulsed 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 was sequentially increased. In addition, monitor pulses Pm for monitoring the state of formation of the electron emission section 1105 are inserted between triangular wave pulses at appropriate intervals, and the current flowing at that time is measured by an ammeter 111.
Measured at 1.

In the embodiment, for example, in a vacuum atmosphere of about 10 −5 [torr], for example, the pulse width T1 is 1 [millisecond] and the pulse interval T2 is 10
[Milliseconds] 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, a monitor pulse Pm was inserted once.
In order not to adversely affect the forming process,
The monitor pulse voltage Vpm was set to 0.1 [V]. The electric resistance between the device electrodes 1102 and 1103 is 1
The current measured by the ammeter 1111 when the monitor pulse is applied at the stage when the current reaches × 10 6 [ohm], that is, 1 ×
At the stage when 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 element electrode interval L, is changed. In such a case, it is desirable to appropriately change the energization conditions accordingly.

(4) Next, as shown in FIG.
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.) By performing the activation process, the emission current at the same applied voltage is typically smaller than that before the activation. Specifically, it can be increased by 100 times or more.

Specifically, 10 minus the fourth 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. 10A 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 voltage Vac of the rectangular wave is 14 [V],
The pulse width T3 is 1 [millisecond], and the pulse interval T4 is 10
[Milliseconds]. Note that the above-described energization conditions are preferable conditions for the surface conduction electron-emitting device of the present embodiment, and when the design of the surface conduction electron-emitting device is changed, it is desirable to appropriately change the conditions accordingly.

Reference numeral 1114 shown in FIG. 8D denotes an anode electrode for capturing the emission current Ie emitted from the surface conduction electron-emitting device. The anode electrode 1114 is connected to a DC high voltage power supply 1115 and an ammeter 1116. (When the activation process is performed after the substrate 1101 is incorporated into the display panel 14, the phosphor screen of the display panel 14 is
4). While the voltage is applied from the activation power supply 1112, the emission current Ie is measured by the ammeter 1116 to monitor the progress of the energization activation process, and the activation power supply 11
12 is controlled.

The emission current Ie measured by the ammeter 1116
FIG. 10B shows an example. Here, the activation power supply 1
When the pulse voltage starts to be applied from 112, 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. 8E was manufactured.

(Vertical Type Surface Conduction Emission Element) Next, another typical configuration 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 type emission device. The configuration of the element will be described.

FIG. 11 is a schematic cross-sectional view for explaining a basic structure of a vertical type. In FIG.
202 and 1203 are device electrodes, 1206 is a step forming member, 1204 is a conductive thin film using a fine particle film, 1205
Are electron-emitting portions formed by an energization forming process;
213 is a thin film formed by the activation process.

The difference between the vertical type and the flat type is that one of the element electrodes (1202) is a step forming member 120.
6 in that the conductive thin film 1204 covers the side surface of the step forming member 1206. Therefore,
The element electrode interval L in the planar type shown in FIG. 7 is set as the step height Ls of the step forming member 1206 in the vertical type. The substrate 1201, the device electrodes 1202 and 12
03. For the conductive thin film 1204 using the fine particle film, the materials listed in the description of the flat type can be used in the same manner. In addition, the step forming member 1206 includes:
For example, an electrically insulating material such as SiO2 is used.

Next, a method for manufacturing a vertical surface conduction electron-emitting device will be described. FIGS. 12A to 12F 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 thereover. (2) Next, as shown in FIG. 2B, an insulating layer for forming a step forming member is laminated. The insulating layer is made of, for example, S
iO2 may be deposited by a sputtering method, but another film forming method such as a vacuum evaporation method or a printing method may be used. (3) Next, as shown in FIG. 3C, an element electrode 1202 is formed on the insulating layer. (4) Next, as shown in FIG. 4D, a part of the insulating layer is removed by using, for example, an etching method, and the device electrode 12 is removed.
03 is exposed. (5) Next, as shown in FIG. 5E, a conductive thin film 1204 using a fine particle film is formed. For the formation, as in the case of the planar type, a film forming technique such as a coating method may be used. (6) Next, as in the case of the flat type, an energization forming process is performed to form an electron emission portion. (FIG. 8 (c)
A process similar to the planar energization forming process described with reference to FIG. (7) Next, as in the case of the flat type, a current activation process is performed to deposit carbon or a carbon compound near the electron emission portion. (A process similar to the planar energization activation process described with reference to FIG. 8D may be performed.) As described above, the vertical surface conduction electron-emitting device shown in FIG. Manufactured.

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

FIG. 13 shows typical examples of (emission current Ie) versus (element applied voltage Vf) characteristics and (element current If) versus (element applied voltage Vf) characteristics of the elements used in the display device. . Note that the emission current Ie is significantly smaller than the device current If, and it is difficult to show them on the same scale. In addition, these characteristics are changed by changing design parameters such as the size and shape of the device. Therefore, each of the two graphs is shown in arbitrary units.

The element used in the image display device of the present embodiment has the following three characteristics with respect to 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 varies with the voltage Vf.
Size can be controlled.

Third, since the response speed of the current Ie emitted from the device is fast with respect to the voltage Vf applied to the device, the amount of charge of the electrons emitted from the device 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 an image display device. For example, in a display device in which a large number of elements are provided corresponding to pixels of a display screen, display can be performed by sequentially scanning the display screen by using the first characteristic. 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, display can be performed by sequentially scanning the display screen.

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

(Structure of a Multi-Electron Source in Which Many Devices are Wired in a Simple Matrix) The structure of a multi-electron source in which the above-mentioned surface conduction electron-emitting devices are arranged on a substrate and wired in a simple matrix will be described.

FIG. 14 shows the display panel 14 of FIG.
FIG. 4 is a plan view of the multi-electron source used for FIG. On the substrate, surface conduction type emission elements similar to those shown in FIG. 7 are arranged, and these elements are wired in a simple matrix by row-direction wiring electrodes 1003 and column-direction wiring electrodes 1004. Row direction wiring electrode 1003 and column direction wiring electrode 1004
An insulating layer (not shown) is formed between the electrodes at the intersections of the two to maintain electrical insulation.

FIG. 15 is a sectional view taken along the line AA ′ of FIG.
Shown in

Incidentally, 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. 16 shows that the display panel 14 using the surface conduction electron-emitting device of this embodiment as an electron source can display image information provided from various image information sources such as television broadcasting. It is a figure for showing an example of the multifunctional display constituted as above. In the figure, 14 is a display panel, 2101 is a drive circuit of the display panel 14, 2102 is a display controller, 21
03 is a multiplexer, 2104 is a decoder, 2105
Is an input / output interface circuit, 2106 is a CPU, 2
107 is an image generation circuit, 2108 and 2109 and 2110 are image memory interface circuits, 2111
Are image input interface circuits, 2112 and 21
13 is a TV signal receiving circuit, and 2114 is an input unit. Note that, when the display device of the present embodiment receives a signal including both video information and audio information, such as a television signal, the display device naturally reproduces the audio simultaneously with the display of the video. Descriptions of circuits, speakers, and the like related to reception, separation, reproduction, processing, storage, and the like of audio information that are not directly related to the features of the present embodiment are omitted. Hereinafter, the function of each unit will be described along the flow of the image signal.

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.

Image input interface circuit 2111
Is 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 the decoder 2104. The image memory interface circuit 2110 includes:
This is a circuit for capturing an image signal stored in a video tape recorder (hereinafter abbreviated as VTR). The captured image signal is output to a decoder 2104. The image memory interface circuit 2109 is a circuit for taking in an image signal stored in the video disk, and the taken-in image signal is output to the decoder 2104. Further, the image memory interface circuit 2108 is a circuit for taking in an image signal from a device storing still image data, such as a so-called still image disk, and the taken still image data is output to the decoder 2104.

The input / output interface circuit 2105 is
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. .

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 the CPU 210.
6 is a circuit for generating display image data based on the image data and character / figure information output from 6. 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
4, but it is also possible to input / output 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 image signals to be displayed on the display panel are 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. Note that the CPU 2106
Of course, it may be related to 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, as described above, the computer may be connected to an external computer network via the input / output interface circuit 2105 and work such as numerical calculation may be performed in cooperation with an external device.

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. The decoder 2104 is connected to the 2107 to 2113.
This is a circuit for inversely converting various input image signals into three primary color signals or a luminance signal and I and Q signals. As shown by the dotted line in FIG.
4 preferably has an image memory inside. this is,
This is because, for example, a television signal that requires an image memory when performing inverse conversion, such as the MUSE method. Further, the provision of the image memory facilitates display of a still image, or the image generation circuit 210
This is because there is an advantage that image processing and editing including image thinning, interpolation, enlargement, reduction, and synthesis can be easily performed in cooperation with the CPU 7 and the CPU 2106.

A multiplexer 2103 is connected to the CPU 2
A display image is appropriately selected based on a control signal input from the control unit 106. That is, the multiplexer 210
3 selects a desired image signal from the inversely converted image signals input from the decoder 2104, and
Output to 01. 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. .

Display panel controller 2102
Is 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, a signal for controlling an operation sequence of a display panel driving power supply (not shown) is output to the driving circuit 2101, for example. Further, as a signal related to the display panel driving method, for example, a signal for controlling a screen display frequency and a scanning method (for example, interlaced or non-interlaced) is supplied to the driving circuit 210.
Output for 1 In some cases, a control signal related to image quality adjustment such as luminance, contrast, color tone, and sharpness of a display image may be output to the driving circuit 2101.

The driving circuit 2101 is a circuit for generating a driving signal to be applied to the display panel 14,
It operates based on an image signal input from the multiplexer 2103 and a control signal input from the display panel controller 2102.

The function of each part has been described above. With the configuration illustrated in FIG. 16, in the present display device, image information input from various image information sources is displayed on the display panel 1.
4 can be displayed. That is, various image signals including television broadcasting are supplied to the decoder 2104.
, And are appropriately selected by the multiplexer 2103 and input to the drive circuit 2101. 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 applies a drive signal to the display panel 14 based on the image signal and the control signal. Thereby, the display panel 1
At 4, an image is displayed. These series of actions are:
The CPU 2106 controls the entire system.

Further, in the image display device of the present embodiment, an image memory built in the decoder 2104,
With the involvement of the image generation circuit 2107 and the CPU 2106, not only the image information selected from the plurality of pieces of image information is displayed, but also the image information to be displayed is enlarged, reduced, rotated, moved, edge emphasized, and so on. It is also possible to perform image processing such as thinning, interpolation, color conversion, and image aspect ratio conversion, and image editing such as combining, erasing, connecting, replacing, and fitting. Also,
Although not particularly mentioned 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,
This display device has functions such as display equipment for television broadcasting, terminal equipment for videoconferencing, image editing equipment for handling still and moving images, computer terminal equipment, office terminals including word processors, and game machines. It can be used as a single unit and has a very wide range of applications for industrial or consumer use.

FIG. 16 shows only an example of the configuration of a display device using a display panel 14 using a surface conduction electron-emitting device as an electron source, and the present invention is not limited to this. Needless to say. For example, among the components in FIG. 16, circuits relating to functions that are unnecessary for the intended purpose 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 videophone, it is preferable to add a television camera, an audio microphone, a lighting device, a transmitting / receiving circuit including a modem, and the like 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 made thin, 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.

Even if the present invention is applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus (for example, a copier, a facsimile, etc.) comprising one device Device).

An object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or apparatus, and to provide a computer (or CPU) of the system or apparatus.
And MPU) read and execute the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

As described above, according to the present embodiment, the brightness of a display image can be changed without changing the gradation of the display image data.

[0141]

As described above, according to the present invention, the luminance to be displayed can be adjusted without changing the value of the image signal.

Further, according to the present invention, the luminance can be adjusted so as to obtain the specified luminance without changing the value of the input image signal.

According to the present invention, when the average luminance of an input image signal is high, the light emission luminance can be suppressed without changing the image signal.

Further, according to the present invention, there is an effect that the light emission luminance of the display panel can be adjusted according to the environment where the apparatus is placed or the designation of the user without changing the image signal.

[0145]

[Brief description of the drawings]

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

FIG. 2 is a timing chart for explaining signals of respective parts of the image display device of FIG. 1;

FIG. 3 is a block diagram showing a configuration of an image display device according to Embodiment 2 of the present invention.

FIG. 4 is a flowchart illustrating a brightness adjustment process in a brightness adjustment unit according to the second embodiment.

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

FIG. 6 is a plan view illustrating a phosphor array of a face plate of the display panel of the present embodiment.

FIGS. 7A and 7B 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. 8 is a cross-sectional view showing a manufacturing process of the planar type surface conduction electron-emitting device.

FIG. 9 is a diagram showing an applied voltage waveform during energization forming processing.

FIG. 10 shows an applied voltage waveform (a) during the energization activation process,
It is a figure showing change (b) of discharge current Ie.

FIG. 11 is a sectional view of a vertical surface conduction electron-emitting device used in the present embodiment.

FIG. 12 is a sectional view showing a manufacturing process of the vertical surface conduction electron-emitting device.

FIG. 13 is a graph showing typical characteristics of the surface conduction electron-emitting device of the present embodiment.

FIG. 14 is a plan view of a substrate of the multi-electron source used in the present embodiment.

FIG. 15 is a sectional view taken along line A-A ′ of FIG. 14;

FIG. 16 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. 17 is a view showing an example of a conventionally known surface conduction electron-emitting device.

FIG. 18 is a diagram illustrating an example of a conventionally known FE-type electron-emitting device.

FIG. 19 is a diagram illustrating an example of a conventionally known MIM-type electron-emitting device.

FIG. 20 is a diagram illustrating a wiring method of the electron-emitting device.

[Explanation of symbols]

 Reference Signs List 1 video signal input terminal 2 analog signal processing unit 3 A / D unit 4 synchronization signal separation unit 5 timing generation unit 6 luminance adjustment unit 7 user interface (I / F) unit 8 PWM pulse generation unit 9 vertical shift register 15 average luminance Detector 16 External light sensor 17 Table memory

Claims (18)

[Claims] A display panel having a plurality of electron-emitting devices arranged therein and a luminous body emitting light by electrons emitted from the electron-emitting devices; and driving the plurality of electron-emitting devices in accordance with an input image signal. Driving means; instruction means for instructing light emission luminance in the display panel; and control means for controlling a driving time for driving the electron-emitting device in synchronization with driving by the driving means, based on an instruction from the instruction means. An image display device comprising: 2. The display panel according to claim 1, wherein the plurality of electron-emitting devices are arranged in a matrix by row and column wiring.
The driving unit drives the electron-emitting device via the column-directional wiring, and the control unit changes a pulse width of a pulse signal applied to the row-directional wiring based on an instruction from the instruction unit, thereby changing the driving time. The image display device according to claim 1, wherein the image display device is controlled. 3. The image display according to claim 1, wherein the driving unit outputs a signal having an amplitude corresponding to a value of the input image signal to drive the plurality of electron-emitting devices. apparatus. 4. The control unit according to claim 1, wherein each of the row wirings is sequentially selected in synchronization with a horizontal synchronization signal of the image signal, and an unselected row wiring is set to a ground level. 3. The image display device according to 2. 5. The image processing apparatus according to claim 1, further comprising a detecting unit configured to detect an average luminance of the image signal, wherein the control unit shortens the driving time when the average luminance detected by the detecting unit is equal to or higher than a predetermined level. The image display device according to any one of claims 1 to 4, wherein the image display device performs control. 6. An external light detecting means for detecting the brightness of an environment in which the image display device is installed, wherein the control means includes a luminance detected by the detecting means and the external light detecting means. The image display device according to claim 5, wherein the driving time is determined based on the following. 7. The image display device according to claim 1, wherein the plurality of electron-emitting devices are surface-conduction emission devices. 8. The device according to claim 1, wherein said plurality of electron-emitting devices are FE-type electron-emitting devices.
Item 10. The image display device according to Item 1. 9. The image display device according to claim 1, wherein the plurality of electron-emitting devices are MIM-type electron-emitting devices. 10. A display control method for an image display device having a display panel in which a plurality of electron-emitting devices are arranged and a luminous body that emits light by electrons emitted from the electron-emitting devices is provided. A driving step of driving a plurality of electron-emitting devices in accordance with the following; an instruction step of instructing light emission luminance in the display panel; And a control step of controlling a drive time for driving the display. 11. The display panel, wherein the plurality of electron-emitting devices are arranged in a matrix by row and column wirings, and in the driving step, the electron-emitting devices are driven via the column wirings. 11. The display control method according to claim 10, wherein in the control step, the driving time is controlled by changing a pulse width of a pulse signal applied to the row direction wiring based on the instruction in the instruction step. 12. The display control according to claim 10, wherein in the driving step, a signal having an amplitude corresponding to a value of an input image signal is output to drive the plurality of electron-emitting devices. Method. 13. In the control step, each of the row direction wirings is sequentially selected in synchronization with a horizontal synchronizing signal of the image signal, and non-selected row direction wirings are set to a ground level. 12. The display control method according to item 11. 14. The image processing method according to claim 1, further comprising a detecting step of detecting an average luminance of the image signal, wherein the controlling step reduces the driving time when the average luminance detected in the detecting step is equal to or higher than a predetermined level. 14. The display control method according to claim 10, wherein the display control is performed. 15. An external light detecting step of detecting the brightness of an environment in which the image display device is installed, wherein the control step includes a step of detecting the brightness detected in the detecting step and the external light detecting step. The display control method according to claim 14, wherein the drive time is determined based on the following. 16. The display control method according to claim 10, wherein said plurality of electron-emitting devices are surface conduction electron-emitting devices. 17. The display control method according to claim 10, wherein said plurality of electron-emitting devices are FE-type electron-emitting devices. 18. The display control method according to claim 10, wherein said plurality of electron-emitting devices are MIM-type electron-emitting devices.