JP2000075833A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To faithfully display the colors, brightness and darkness of original image signals on an image display device by taking the light emission characteristic of the image display device into consideration and further, executing γcorrection relating to luminance signals and color signals according to the kinds of input image signals. SOLUTION: This image display device has an electron releasing element, a phosphor which emits light by receiving the electrons released from this electron releasing element, an image signal conversion means which converts the input image signal and outputs the converted image signal and a modulating means for modulating the electron beam released from the electron releasing element. The image signal conversion means restores the input image signal obtd. by gamma correction of the original signal for a cathode ray tube(CRT) to the original signal, converts the restored original signal to the converted image signal to linearize the electron beam intensity-to-phosphor light emission luminance characteristic by correcting the nonlinearity of the electron beam intensity-to-phosphor light emission luminance and outputs this signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for forming an image by irradiating a luminous body with an electron beam.

[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,
MIElinson, Radio Eng. Electron Phys. , 10,12
90, (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. As this surface conduction type emission element, Sn described by Elinson et al.
In addition to those using O ₂ thin films, those using Au thin films [GD
ittmer: “Thin Solid Films”, 9, 317 (197
2)] and those using an In ₂ O ₃ / SnO ₂ thin film [M. Hartw
ell and CGFonstad: “IEEE Trans.ED Conf.”, 519
(1975)] and those using carbon thin films [Hisashi Araki
Others: Vacuum, Vol. 26, No. 1, 22 (1983)].

FIG. 21 is a plan view of a device by M. Hartwell et al. Described above 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 performing an energization process called energization forming described later on the conductive thin film 3004.
The interval L in the figure is 0.5 to 1 [mm], and W is 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., An electron emission portion 3005 is formed by performing an energization process called energization forming on the conductive thin film 3004 before electron emission. Was common. That is, energization forming means that a constant DC voltage is applied to both ends of the conductive thin film 3004,
Alternatively, a current is applied by applying a direct-current voltage that is boosted at a very slow rate of, for example, about 1 V / minute, and locally destroys, deforms, or alters the conductive thin film 3004, and the electrons in an electrically high resistance state That is, forming the emission part 3005. Note that a crack is generated in a part of the conductive thin film 3004 that is locally broken, deformed, or altered. After the energization forming, the conductive thin film 300
When an appropriate voltage is applied to No. 4, electrons are emitted in the vicinity of the crack.

An example of the FE type is, for example, WPDyke
& WWDolan, “Field emission”, Advance in Electron
Physics, 8, 89 (1956) or CASp
indt, “Physical properties of thin-film field emi
ssion cathodes with molybdenium cones ", J. Appl. Phy
s. , 47, 5248 (1976).

FIG. 22 shows a cross-sectional view of a device by CASpindt et al. Described above as a typical example of the FE type device configuration. 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 301
By applying an appropriate voltage during the period 4, field emission is caused from the tip of the emitter cone 3012.

As another element structure 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 plane of the substrate, instead of the laminated structure as in 2.

FIG. 23 shows a typical example of a MIM type device configuration (for example, CAMead, “Operation
of tunnel-emission Devices, J. Appl. Phys. , 32,
646 (1961)). The figure is a sectional view, in which 3020 is a substrate, 3021 is a lower electrode made of a metal, 3022 is a thin insulating layer having a thickness of about 100 Å, and 3023 is an upper layer made of a metal having a thickness of about 80 to 300 Å. Electrodes. 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. Also,
Even if a large number of elements are arranged on a substrate at a high density, problems such as thermal melting of the substrate hardly occur. In addition, unlike the hot cathode device, which operates by heating the heater, the response speed is slow, and the cold cathode device also has the advantage that the response speed is fast.

For this reason, research 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 JP-A-332-332, a method for arranging and driving a large number of elements has been studied.

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

In particular, 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 apparatus using a combination of a mold emission element and a phosphor that emits light by irradiation with an electron beam 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 superior in that it does not require a backlight because it is a self-luminous type and that it has a wide viewing angle.

A method of driving a large number of FE types is disclosed in US Pat. No. 4,904,89 by the present applicant.
5 is disclosed. 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
Development on Microtips Display at LETI ", Tech.Di
gest of 4th Int.Vacuum Microelectronics Conf., Naga
hama, pp. 6-9 (1991)] Further, 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. 3-55738 by the present applicant.

[0017]

SUMMARY OF THE INVENTION The present inventors have developed various materials, including those described in the above-mentioned prior art.
We have tried cold cathode devices with manufacturing method and structure. Furthermore, research has been conducted on a multi-electron beam source in which a large number of cold cathode devices are arranged, and on an image display device using the multi-electron beam source.

The inventors have tried a multi-electron beam source by an electric wiring method shown in FIG. 24, for example. That is, it is a multi-electron beam source in which a large number of cold cathode devices are two-dimensionally arranged and these devices are wired in a matrix as shown. In the figure, 4001 schematically shows a cold cathode element, 4002 shows a row wiring, and 4003 shows a column 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 beam source for an image display device, a desired image is displayed. Elements that are sufficient for displaying are arranged and wired.

In a multi-electron beam source in which cold cathode elements are arranged in a simple matrix, a row-directional wiring 4002 and a column-directional wiring 400 are required to output a desired electron beam.
3 is applied with an appropriate electric signal. For example, to drive one row of the cold cathode devices in the matrix, a selection voltage Vs is applied to the row direction wiring 4002 of the selected row,
At the same time, the non-selection voltage Vns is applied to the row direction wiring 4002 of the non-selected row. In synchronization with this, the column direction wiring 4003
Is applied with a drive voltage Ve for outputting an electron beam. According to this method, wiring resistances 4004 and 4004
If the voltage drop due to 5 is ignored, the voltage of Ve-Vs is applied to the cold cathode elements of the selected row, and the voltage of Ve-Vns is applied to the cold cathode elements of the non-selected rows. V
If e, Vs, and Vns are set to voltages of appropriate magnitudes, an electron beam of a desired intensity should be output only from the cold cathode elements in the selected row, and a different drive voltage Ve is applied to each of the column wirings. If applied, each of the elements in the selected row should output a different intensity electron beam. Further, 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.

Therefore, a multi-electron beam source in which cold cathode devices are arranged in a simple matrix has various applications. For example, if an electric signal corresponding to image information is appropriately applied, it is suitable as an electron source for an image display device. Can be used.

However, the multi-electron beam source in which the cold cathode devices are arranged in a simple matrix has actually caused the following problems.

As described above, in the multi-electron beam source in which the cold cathode devices are arranged in a simple matrix, the row to emit light can be selected by changing the voltage applied to the selected row wiring and the unselected row wiring. Further, the light emission amount of each element in the selected row can be controlled by changing the magnitude of the driving voltage value applied from each column wiring or the time for applying the driving voltage.

That is, in order to display an image signal having a scanning line structure, the number of pixels for one scanning line is made to correspond to the number of lines in each column, and drive voltage application amplitude modulation or drive voltage application time modulation is performed by a luminance signal of each pixel. This is realized by a so-called line-sequential scanning drive in which the voltage is applied to each column wiring and the row wiring is sequentially scanned.

One of the advantages of line sequential driving is that many CRs
Unlike point-sequential driving performed by a raster scan type display device using T, one pixel can be selected for a long time. That is, the luminance can be significantly increased, or the acceleration voltage for accelerating the electron beam can be reduced.

On the other hand, as one of the image signals, there is a TV signal such as NTSC or HDTV. Normally the TV signal is CR
The gamma characteristic of a CRT (a non-linear characteristic of luminance signal-luminance luminance characteristic) is considered for a receiver using T.
Is corrected in advance on the sending side (hereinafter referred to as gamma correction) and output.

That is, when a display device using a display device other than the CRT, such as the present image display device, receives a TV signal, it is necessary to provide a light emission characteristic conversion means for adjusting to the nonlinear light emission characteristics of the CRT.

Conventionally, for example, in the above-mentioned example, when the column wiring is driven by line-sequential driving by pulse width modulation for applying a voltage having a pulse width corresponding to the luminance signal intensity, the time and luminance of the electron beam emitted from the cold cathode device Since the data has a linear relationship, only light emission characteristic conversion called so-called inverse gamma correction for canceling the gamma characteristic of the input TV signal has been performed.

However, the adoption of line-sequential driving increases the selection time of one pixel. As a result, the illuminant (fluorescent material) of one pixel receives an electron beam irradiation too long. In some cases, a so-called saturation phenomenon may occur in which the amount of light emission becomes in proportion to the electron beam irradiation time.

The degree of the saturation varies depending on the type of phosphor, electron beam density, electron beam irradiation time, and the like.

Due to the saturation phenomenon of the phosphor, the relationship between the luminance signal and the light emission amount may be broken only by the inverse gamma correction of the TV signal. In addition, since the state of saturation changes depending on the type of phosphor, the color balance of the displayed image may be lost in some cases.

Alternatively, when the display device receives a plurality of types of input signals such as a TV signal and an image signal of a personal computer (hereinafter abbreviated as a PC), the light emission luminance is changed between when the TV signal is displayed and when the PC signal is displayed. May change. In this case, the color balance of one of the input signals may be lost.

Further, when the display device performs so-called ABL control to reduce the average brightness of the entire screen even if the peak brightness is large in order to suppress power consumption, the color balance of the displayed image may be lost by the ABL control. There is a risk that it will.

Therefore, the present invention takes into account the light emission characteristics of the image display device and further performs gamma correction on the luminance signal and the color signal in accordance with the type of the input image signal to faithfully adjust the color and brightness of the original image signal. It is an object to display on an image display device.

[0035]

According to the present invention, there is provided an electron emitting device, a phosphor which emits light by receiving electrons emitted from the electron emitting device, and converts an input image signal. An image display method using an image display device, comprising: an image signal conversion unit that outputs a converted image signal by using the image display device; and a modulation unit that modulates the intensity of an electron beam emitted from the electron-emitting device based on the converted image signal. The image signal converting means restores the input image signal obtained by gamma-correcting the original signal for a cathode ray tube (CRT) to the original signal,
The restored original signal is converted into the converted image signal that corrects the non-linearity of the electron beam intensity versus the phosphor emission luminance and makes the electron beam intensity versus the phosphor emission luminance characteristic a straight line, and outputs the converted image signal. I have.

[0036]

Embodiments of the present invention will be described below with reference to the drawings. [Embodiment 1] In a first embodiment, a multi-electron beam source in which a plurality of surface conduction elements are arranged in a matrix by a plurality of row wirings and column wirings, and a phosphor screen which emits light upon receiving electron beam irradiation from each electron beam source An example will be described in which a TV signal is displayed on a display panel having the following (hereinafter, referred to as an SED panel).

FIG. 1 is a block diagram of a drive circuit of the SED panel.

P2000 is a display panel. In this embodiment, 240 * 720 surface conduction elements P20
01 are matrix-wired by 240 vertical row wirings and 720 horizontal column wirings, and each surface conduction element P2001
The emitted electron beam is accelerated by a high-voltage applied from the high-voltage power supply unit P30, and is emitted to a phosphor (not shown) to emit light. The phosphor (not shown) can have various color arrangements depending on the application. For example, an RGB vertical stripe color arrangement is used.

In the present embodiment, the horizontal 240
(RGB trio) * An application example of displaying an NTSC-equivalent television image on a display panel having 240 vertical pixels is shown. However, the resolution is not limited to NTSC, such as high-definition images such as HDTV and computer output images. And image signals having different frame rates can be easily handled with almost the same configuration.

FIG. 2 shows an NTSC-type video receiver which receives an NTSC composite video input and outputs RGB components.
4 shows an RGB decoder section P1. In this unit, a synchronization signal (SYNC) superimposed on the input video signal is separated and output. Similarly, a color burst signal superimposed on the input video signal is separated, and a CLK signal (CLK1) synchronized with the color burst signal is generated and output.

FIG. 3 shows a timing generator for generating the following timing signals necessary for converting the analog RGB signals decoded at P1 into digital gradation signals for luminance modulation of the SED panel. Indicates P2. The signal output from this timing generator P2 is the signal from P1
A clamp pulse for DC reproduction of the GB analog signal in the analog processing unit P3, a blanking pulse (BLK pulse) for adding a blank period to the RGB analog signal from P1 in the analog processing unit P3, and RGB.
A detection pulse for detecting the level of the analog signal by the video detection unit P4 and an analog RGB signal
6, a sample pulse (not shown) for converting to a digital signal, and the RAM controller P12
Control signal required to control the clock signal, and a PLL generated in P2 and input to CLK1 and input to PLL in P2.
A free-running CLK signal (CLK
2) and a synchronization signal (SYNC2) generated based on CLK2 in P2.

This timing generator P2 is a self-running CLK
By providing the two-generation means, even when there is no input video signal, the reference signals CLK2 and SYNC2 can be generated, so that an image can be displayed by reading the image data of the RAM means P8.

FIG. 4 shows an analog processing section P3 provided for each of the output primary color signals from P1. The analog processing unit P3 receives a clamp pulse from P2 and performs DC regeneration. In addition, a blanking period is added by receiving a BLK pulse from P2.

The D / A unit P which is one of the control outputs of the system control unit mainly composed of the MPUP 11
Upon receiving the gain adjustment signal of No. 14, the amplitude control of the primary color signal input from P1 is performed.

The D / A unit P, which is one of the control outputs of the system control unit mainly composed of the MPUP 11,
In response to the 14 offset adjustment signals, the black level of the primary color signal input from P1 is controlled.

P4 is a video detecting section for detecting the input video signal level or the video signal level after being controlled by the analog processing section P3. The video detecting section receives a detection pulse from P2. The detection result is read by the A / D unit P15 which is one of the control inputs of the system control unit configured.

The detection pulse from P2 is, for example, a gate pulse, a reset pulse, a sample & hold (hereinafter S
/ H) pulse, and the video detection unit is composed of, for example, an integrating circuit and an S / H circuit.

For example, during the valid period of the input video signal by the gate pulse, the video signal is integrated by the above-mentioned integration circuit, and the output of the integration circuit is sampled by the S / H circuit by the S / H pulse generated during the vertical blanking period. A /
After the detection result is read by the D section P15, the integration circuit and the S / H circuit are initialized by the reset pulse.

With such an operation, the average video level for each field can be detected.

The LPFP 5 is a pre-filter means placed before the A / D section P6.

The A / D section P6 is a sample CL from P2.
A / D converter means which receives K and quantizes the analog primary color signal having passed through the LPFP 5 with a required number of gradations.

The conversion table P7 is a gradation characteristic conversion means provided for converting an input video signal into light emission characteristics of the display panel. When a luminance gradation is expressed by pulse width modulation as in the present embodiment, a linear characteristic in which the amount of light emission is almost proportional to the size of luminance data is often exhibited. On the other hand, since the video signal is intended for a TV receiver using a CRT, the video signal is subjected to gamma processing in order to correct the non-linear emission characteristics of the CRT. For this reason, a panel having linear light emission characteristics as in the present embodiment is provided with a TV.
When displaying an image, it is necessary to cancel the effect of the gamma processing by the gradation characteristic conversion means such as P7.

The table data is switched by the output of the I / O control unit P13, which is one of the control inputs and outputs of the system control unit mainly composed of the MPUP 11, so that the light emission characteristics can be changed as desired.

P8 is an image memory provided for each R / G / B processing circuit and has addresses corresponding to the total number of display pixels of the panel (in this case, horizontal 240 * vertical 240 *
3). The luminance data to be emitted by each pixel of the panel is stored in this memory, and the luminance data is read out in a dot-sequential manner to display the image stored in the memory on the panel.

The output of the luminance data from P8 is performed under the address control from the RAM controller P12.

Data writing to P8 is performed by MPUP1
1 is performed under the control of the system control unit mainly composed of For simple test patterns, M
The PUP 11 calculates and generates and writes the luminance data stored in each address of P8. In the case of a pattern such as a natural still image, for example, an image file stored in an external computer or the like is read via the serial communication I / FP 16 which is one of the input / output units of the system control unit mainly composed of the MPUP 11, and is read. Write to the memory P8.

P9 is a data selector which determines whether to output image data from the image memory P8,
Whether the data is from the D section P6 (input video signal system) is determined by the output of the I / O control section P13 which is one of the control inputs and outputs of the system control section mainly composed of the MPUP11.

In addition to the input selection of the two systems, there is a mode for generating a fixed value from P9, and this mode can be selected and output by P13. With this mode,
For example, an adjustment signal such as an all-white pattern can be displayed at high speed without an external input.

P10 is a horizontal one-line memory means provided for each primary color signal.
, The luminance data input in parallel to the three RGB systems are rearranged in an order according to the panel color arrangement, converted into one system serial signal, and output to the X driver unit via the latch means P22.

The system control section is mainly composed of MPUP1
1, serial communication I / FP16, I / O control unit P13,
D / A section P14, A / D section P15, data memory P1
7. It is composed of a user SW means P18.

The system control section includes a user switch
The request is realized by receiving a user request from the means P18 or the serial communication I / FP 16 and outputting a corresponding control signal from the I / O control unit P13 or the D / A unit P14.

Further, upon receiving the system monitoring signal from the A / D unit P15, the corresponding control signal is transmitted to the I / O control unit P13 or D / O control unit.
Optimal automatic control is performed by output from the / A section P14.

In this embodiment, display control such as test pattern generation, variable gradation, brightness, and color control can be realized as user requests. Also, as described above, the average video level from the video detection unit P4 is calculated by the A / D unit P15.
The automatic control of ABL or the like can be performed by monitoring with.

By providing the data memory P17, the user adjustment amount can be stored.

P19 is a Y driver control timing generator, P20 is an X driver control timing generator,
Both receive the CLK1, CLK2 and SYNC2 signals and generate Y driver control and X driver control signals.

P21 is a control unit for controlling the timing of the line memory P10.
An R, G, B WRT control signal for receiving the SYNC2 signal and writing the luminance data to the line memory and an R, G, B RD control signal for reading the luminance data from the line memory in an order according to the panel color arrangement are generated. .

FIG. 5 is a time chart for explaining the operation of the SED drive circuit.

T104 is a waveform of a color sample data string written with one of the RGB colors as an example, and is composed of 240 data strings in one horizontal period. This data string is written into the line memory P10 by the control signal in one horizontal period. In the next horizontal period, the line memory P10 for each color is read and enabled at a frequency three times as high as that in the case of writing, thereby obtaining 720 luminance data strings per one horizontal period such as T105.

An X and Y driver timing generator P1001 receives control signals from the Y driver control timing generator P19 and the X driver control timing generator P20. The signal output from P1001 is used for fetching the shift clock and the data read into shift registers P1101 and 1107 to a memory means (not shown) in PWM generator section P1102 and D / A section P1103, and to output the signals from PWM generator section P1102. D / A
LD acting as trigger of horizontal cycle to section P1103
A pulse, an If table ROM control signal, a horizontal cycle shift clock for moving the Y shift register for Y driver control, and a vertical cycle trigger signal for providing a row scanning start trigger.

The shift register P1101 is a shift clock synchronized with the luminance data string of 720 column wirings per horizontal cycle from the latch means P22 in synchronism with the luminance data as shown in FIG. 2T107 from the X, Y driver timing generator P1001. , And 720 pulses in the PWM generator unit P1102 by an LD pulse such as T108.
Transfer data for horizontal rows at a time.

The shift register P1107 reads the column wiring driving current data string of 720 column wirings per horizontal cycle from the data selector means P1201 by the shift clock in the same manner as the luminance data, and outputs the D / D signal by the LD pulse such as T108. The data for 720 horizontal rows is transferred to the A section P1103 at a time.

The If table ROM P1202 is a memory means for storing data of the current amplitude value to be passed to each of the 720 * 240 surface conduction type elements of the display panel P2000, and the X and Y driver timing generator P100
The read address control is performed by the If table ROM control signal from 1 and the data of 720 current amplitude values for one row to be scanned as shown in FIG.

By using the If table ROMP 1202 to set the current value for driving this column wiring (that is, the surface conduction type element) to an optimum value for each element, the uniformity of luminance can be extremely improved.

Further, If table ROMP 1202 has 7
It is also possible to provide 20 * 240 pieces of current amplitude value data as one bank and provide a plurality of types of banks. For example, when the light emission luminance of the panel is switched in a plurality of stages, the current amplitude data to be passed to each element is stored in the bank corresponding to each stage, and one of the control inputs and outputs of the system control unit mainly composed of the MPUP11. A configuration in which an If data bank corresponding to a desired brightness is selected by a bank switching signal output from the I / O control unit P13.

A data selector means P1201 is provided for the case where the If table ROMP1202 is not used for the purpose of cost reduction or the like.
Output from the I / O control unit P13, which is one of the control inputs and outputs of the system control unit configured around
The f setting data can be output to the shift register P1107 by a switching signal from the I / O control unit P13. This makes it possible to control the display luminance of the panel by changing the output If data.

A PWM generator section P1102 provided for each column wiring receives the luminance data from the shift register P1101, and receives a pulse signal having a pulse width proportional to the data size in each horizontal cycle as shown in a waveform T110 in FIG. Occurs.

D / A section P110 provided for each column wiring
Reference numeral 3 denotes a current-output digital-to-analog converter which receives data of the current amplitude value from the shift register P1107 and outputs a drive current having a current amplitude proportional to the data size for each horizontal cycle as shown in a waveform T111 in FIG. appear.

Reference numeral P1104 denotes switch means constituted by a transistor or the like. The switch P1104 applies a current output from the D / A unit P1103 to the column wiring during a period in which the output from the PWM generator unit P1102 is valid, and outputs a signal from the PWM generator unit P11.
The column wiring is grounded during the period in which the output from 02 is invalid. FIG.
An example of a column wiring drive waveform is shown at T111.

Diode means P1 provided for each column wiring
105 is a Vmax regulator P1106 on the common side.
Connected to. The Vmax regulator P1106 is a constant voltage source capable of sinking current, and is a diode means P11
05 and 720 * 24 of the display panel P2000
A protection circuit for preventing an overvoltage from being applied to each of the zero surface conduction type elements is formed.

The protection voltage (the potential defined by Vmax and −Vss applied when scanning of the row wiring is selected) is MP
This is provided by a D / A unit P14, which is one of the control inputs and outputs of the system control unit mainly composed of the UP11.

Accordingly, it is possible to change the Vmax potential (or -Vss potential) for the purpose of luminance control, in addition to the element overvoltage prevention.

That is, if If data for increasing the output current of the D / A section P14 is given and the protection diode means P1105 is always set to conduct, the selection potential of the surface conduction element P2001 becomes (Vmax + Vs
s), the luminance control can be realized by changing the Vmax potential (or -Vss potential).

The Y shift register section P1002 is connected to P10
Reference numeral 01 denotes a pre-driver provided with a horizontal period shift clock from an X, Y driver timing generator and a vertical period trigger signal for giving a row scanning start trigger, and a selection signal for scanning a row wiring for each row wiring. Part P10
03 sequentially.

The output section for driving each row wiring is composed of, for example, transistor means P1006, FET means P1004, and diode means P1007. The pre-driver section P1003 drives this output section with good response. The FET means P1004 is a switch means which conducts when a row is selected, and is a constant voltage regulator P1005 when selected.
Is applied to the row wiring. The transistor means P1006 is a switch means that conducts when a row is not selected, and Vu from the constant voltage regulator unit P1005 when not selected.
The so potential is applied to the row wiring. FIG. 2T112 shows an example of the row wiring drive waveform.

The diode means P1007 is provided for preventing occurrence of an abnormal potential in the row wiring and protecting the output section for driving each row wiring. The constant voltage regulators P1005 and 1008 that generate the -Vss and Vso potentials are MPUP11
Is controlled by the D / A unit P14, which is one of the control inputs and outputs of the system control unit mainly composed of

Similarly, the high-voltage power supply unit P30 is also connected to the MPUP1
1 is controlled by a D / A unit P14, which is one of the control inputs / outputs of the system control unit composed mainly of the control unit 1.

In this embodiment having the above configuration,
Calculation of the correction data stored in the conversion table P7 is performed as follows.

Assume that the luminance data is x1 (x is an integer from 0 to (2 n -1) when the number of gradations is n bits), and the conversion characteristic of the gamma correction performed on the TV signal transmitting side is f1 (x1). , F1 (x1) is assumed to be g1 (x1).

The pulse width modulation data is x2, and the nonlinear characteristic curve of the luminance-pulse width data of the SED panel is f
2 (x2), and the inverse function of f2 (x2) is g2 (x2)
First, x1 'is calculated in order to cancel the gamma correction performed on the TV signal transmitting side.

X1 ′ = (g1 (x1) / g1 (x1max)) × (x1) (conversion formula 1) Next, x2 ′ is calculated to cancel the nonlinear characteristic curve of the luminance-pulse width data of the SED panel. I do.

X2 ′ = (g2 (x2) / g2 (x2max)) × (x2) (conversion formula 2) x2 ′ obtained by substituting x1 ′ obtained by conversion formula 1 into x2 of conversion formula 2 Approximate to an integer value, x for input x
A table P7 for outputting 2 'is created. (Table R
The address signal of OM (P7) is made to correspond to x, and x2 'is stored in the memory corresponding to that address).

More specifically, the following may be performed.

FIG. 6 shows an example of a gamma correction conversion curve performed on the TV signal transmitting side to correct the gamma characteristic of the CRT. According to the literature (edited by Japan Broadcasting Corporation, Hi-Vision Technology, p. 47), an approximate curve of γ = 0.45 is often used. Accordingly, an approximate curve of γ = 2.2 may be used as a function for inverse γ correction (corresponding to the above g (x1)).

FIG. 7 shows the SED used in this embodiment.
9 shows normalized luminance-gradation data (approximately proportional to the drive voltage pulse width) of the panel. By calculating the inverse function of the approximation function of the upwardly convex curve, the nonlinearity of the SED panel can be corrected as in the case of the inverse gamma correction.

As can be seen from FIG. 7, the nonlinearity of the SED panel differs depending on the RGB phosphor. By calculating the inverse function of the approximation function of the convex curve for each color, it is possible to correct the nonlinear difference for each color.

In this example, the emission characteristic of R is γ =
The emission characteristic of 0.72, G can be approximated by γ = 0.9, and the emission characteristic of B can be approximated by γ = 1. Since this value may change depending on the driving condition of the panel, the above is merely an example, and it is necessary to calculate the value according to the driving condition of the panel.

The method of creating table data by power function approximation has been described above. However, the present invention is not limited to this, and another function approximation or an actual panel characteristic measurement curve may be used. [Second Embodiment] A second embodiment of the present invention will be described with an example in which a display device having the configuration shown in FIG. 1 can further receive an HDTV signal and a computer signal in addition to an NTSC signal.

That is, the second embodiment has a configuration in which an input signal switching section as shown in FIG. 5 is provided at the preceding stage of FIG.

P40, P41 and P42 are NTSC signals,
An interface unit corresponding to an HDTV signal and a computer signal. The interface unit converts the resolution of an input signal according to the number of pixels of the display panel P2000, and outputs the converted signal in the form of an RGB component signal and a SYNC signal.

P44 is a signal switching section such as a remote controller accessed by the user, and sends a selection signal for selecting which input signal to display to the signal discriminating section P45.

A signal discriminating section P45 receives the selection signal from P44 and supplies a switching signal to the signal selector section P43.

The signal discriminating section P45 receives a status signal from each of the I / F sections P40 to P42. For example, when only one type of signal is input, the signal selector section P43 automatically displays the signal. To the switching signal.

P43 is a signal selector, which selects and outputs one of the three types of input signals according to the switching signal from the signal discriminator P45.

The signal discriminating section P45 gives information on which signal is currently selected to the system control section mainly composed of the MPUP 11 in FIG.

The system control section can determine the type of the image signal to be received at present based on this information.

For example, when displaying a TV signal such as an NTSC signal or an HDTV signal, it is desirable to have a high luminance for viewing away from the display screen, and when displaying a PC signal, it is desirable to reduce the luminance for viewing near the display screen. .

At this time, the system control unit uses the luminance control method (controls If data, Vmax, -Vss, etc.) described in the first embodiment according to the type of input to be received, and Perform control.

When the brightness control is performed, the nonlinearity of the normalized brightness-gradation data of the SED panel may change (the higher the light emission brightness, the stronger the upward convexity). Therefore, by switching to the conversion table P7 corresponding to the type of the image signal at the same time as the luminance control according to the input signal,
A suitable display image can be obtained regardless of the input signal. [Third Embodiment] In a third embodiment of the present invention, an average luminance level of an input image signal is detected in the display device having the configuration shown in FIG. An example will be described in which so-called ABL control for suppressing the light emission luminance of the entire panel is sometimes performed.

In the operation described in the first embodiment, R
An average input luminance level for each color is detected by a video detector P4 provided for each GB in an analog amount, and is read into the system controller as a digital value by an A / D converter of the system controller at P15. The MPUP 11 of the system control unit monitors, for example, the average input luminance level for each field cycle, and when the average input luminance level exceeds a certain threshold, the luminance control method (If data or Vmax, -V
ss, etc.) to control the brightness. The greater the average input luminance level is, the more the luminance suppression control is applied so that the average light emission luminance over the entire panel does not exceed a certain threshold.

In the third embodiment, the conversion table P7 is switched in conjunction with the brightness control that is performed when the average input brightness level exceeds a certain threshold.

That is, when the average input luminance level is low and the luminance suppression control does not work, the density of the electron beam irradiating the phosphor is high, and the light emission amount is saturated as the luminance data increases. At this time, a conversion table for low average input luminance level in which a large saturation characteristic is corrected in addition to the inverse gamma correction is selected.

When the average input luminance level is high and the luminance suppression control is strong, the electron beam density for irradiating the phosphor is reduced, and the saturation characteristic based on the luminance data of the light emission amount is reduced. At this time, a conversion table for high average input luminance level in which small saturation characteristics are corrected in addition to the inverse gamma correction is selected.

In this way, a conversion table is prepared in which the steps are divided into a plurality of stages from the low average input luminance level to the high average input luminance level, and in addition to the inverse gamma correction, the saturation table representing the stages is corrected. By switching the conversion table, a suitable display image can be obtained. (Configuration and Manufacturing Method of Display Panel) Next, the configuration and manufacturing method of the display panel of the image display device to which the present invention is applied will be described with reference to specific examples.

FIG. 9 is a perspective view of a display panel used in the embodiment, in which a part of the panel is cut away to show the internal structure.

In the figure, 1005 is a rear plate, 1006
Is a side wall, 1007 is a face plate, 1005
1007 form an airtight container for maintaining the inside of the display panel at a vacuum. When assembling an airtight container, it is necessary to seal the joints of the members to maintain sufficient strength airtightness.For example, apply frit glass to the joints, Sealing was achieved by baking at 400 to 500 degrees 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
Is fixed, but the cold cathode device 1002 is provided on the substrate.
(N and M are positive integers of 2 or more, and are appropriately set according to the target number of display pixels. For example, a display for displaying a high-definition television) In the apparatus, it is desirable to set a number of N = 3000 and M = 1000 or more. In the present embodiment, N = 3072 and M = 1024.) N ×
The M cold cathode elements are arranged in a simple matrix by M row-directional wirings 1003 and N column-directional wirings 1004. The portion constituted by 1001 to 1004 is called a multi-electron beam source. The manufacturing method and structure of the multi-electron beam source will be described later in detail.

In the present embodiment, the substrate 1001 of the multi-electron beam source is fixed to the rear plate 1005 of the airtight container.
01 has sufficient strength, the substrate 10 of the multi-electron beam source is used as a rear plate of the hermetic container.
01 itself may be used.

A fluorescent film 1008 is formed on the lower surface of the face plate 1007. Since the present embodiment is a color display device, the fluorescent film 1008 has C
Phosphors of three primary colors of red, green, and blue used in the field of RT are separately applied. The phosphor of each color is, for example, as shown in FIG.
As shown in FIG. 2A, a black conductor 1010 is provided between stripes of the phosphor, which are separately applied in stripes. The purpose of providing the black conductor 1010 is to prevent the display color from being shifted even if there is a slight shift in the electron beam irradiation position, and to prevent the reflection of external light to prevent a decrease in display contrast. And preventing charge-up of the fluorescent film by the electron beam. Although graphite is used as a main component for the black conductor 1010, any other material may be used as long as it is suitable for the above purpose.

The method of applying the phosphors of the three primary colors is not limited to the stripe arrangement shown in FIG. 22A, but may be, for example, a delta arrangement as shown in FIG. Other arrangements may be used.

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

A metal plate 1009 known in the field of CRT is provided on the surface of the fluorescent film 1008 on the rear plate side.
Is provided. The purpose of providing the metal back 1009 is
A part of the light emitted from the fluorescent film 1008 is specularly reflected to improve the light utilization rate, and the fluorescent film 10
08, protect the electrode 08, and act as an electrode for applying an electron beam acceleration voltage, and act as a conductive path for the excited electrons of the fluorescent film 1008. The metal back 1009 was formed by forming a fluorescent film 1008 on the face plate substrate 1007, smoothing the surface of the fluorescent film, and vacuum-depositing Al thereon. 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 an acceleration voltage and improving the conductivity of the fluorescent film, a transparent material made of, for example, ITO is provided between the face plate substrate 1007 and the fluorescent film 1008. Electrodes may be provided.

Further, Dx1 to Dxm and Dy1 to Dy
n and Hv are electric connection terminals having an airtight structure provided for electrically connecting the display panel and an electric circuit (not shown). Dx1 to Dxm are electrically connected to the row wiring 1003 of the multi-electron beam source, Dy1 to Dyn are electrically connected to the column wiring 1004 of the multi-electron beam source, and Hv is 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 raised to the power of 10 −7 [T
orr]. Thereafter, the exhaust pipe is sealed, but a getter film (not shown) is formed at a predetermined position in the airtight container immediately before or after the sealing in order to maintain the degree of vacuum in the airtight container. 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,
Due to the adsorption action of the getter film, the inside of the airtight container is 1 × 10−5 or 1 × 10−7 [Torr].
Is maintained at a vacuum degree.

The basic structure and manufacturing method of the display panel according to the embodiment of the present invention have been described above.

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

However, in a situation where 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, in the FE type, since the relative position and shape of the emitter cone and the gate electrode greatly affect the electron emission characteristics, extremely high-precision manufacturing technology is required, but this achieves a large area and a reduction in manufacturing cost. Is a disadvantageous factor. In the case of the MIM type, it is necessary to make the thicknesses of the insulating layer and the upper electrode thin and uniform, which is also a disadvantageous factor in achieving a large area and a reduction in manufacturing cost. On the other hand, 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. In addition, the inventors have found that among the surface conduction electron-emitting devices, those in which the electron-emitting portion or its peripheral portion is formed of a fine particle film have particularly excellent electron-emitting characteristics and can be easily manufactured. Therefore, it can be said that it is most suitable for use in a multi-electron beam source of a high-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 configuration, manufacturing method and characteristics of a suitable surface conduction electron-emitting device will be described first, and then the structure of a multi-electron beam source in which many devices are arranged in a simple matrix will be described. (Suitable device configuration and manufacturing method of surface conduction type emission device) The typical configuration of the surface conduction type emission device in which the electron-emitting portion or its peripheral portion is formed of a fine particle film is a flat type or a vertical type.
Kinds are given. (Flat-type surface conduction electron-emitting device) First, an element configuration and a manufacturing method of a flat-type surface conduction electron-emitting device will be described.

FIGS. 11A and 11B are a plan view and a sectional view, respectively, for explaining the structure of a planar type surface conduction electron-emitting device. In the figure, 1101 is a substrate, 1102 and 1
103, a device electrode; 1104, a conductive thin film; 1105, an electron-emitting portion formed by an energization forming process;
Reference numeral 13 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 from metals such as Ag, alloys of these metals, metal oxides such as In ₂ O ₃ —SnO ₂ , and semiconductors such as polysilicon. An electrode 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 electrode can be formed by other methods (for example, printing technique). 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 spacing L is usually designed by selecting an appropriate value from the range of several hundreds of angstroms to several hundreds of micrometers. It is in the range of ten micrometers. Further, regarding the thickness d of the device electrode,
Usually, an appropriate numerical value is selected from the range of several hundred angstroms to several micrometers.

A fine particle film is used for the portion of the conductive thin film 1104. The fine particle film mentioned here is a film containing many fine particles as a constituent element (including an island-shaped aggregate).
I mean If you examine the microparticle film microscopically, usually
A structure in which the individual fine particles are spaced apart, 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 preferably in the range of 10 Angstroms to 200 Angstroms. Further, the thickness of the fine particle film is appropriately set in consideration of various conditions described below. That is, the device electrode 11
02, or 1103, conditions necessary for satisfactorily performing energization forming described later, conditions necessary for setting the electric resistance of the fine particle film itself to an appropriate value described later. , And so on. In particular,
The setting is made in the range of several Angstroms to several thousand Angstroms, and a preferable value is between 10 Angstroms and 500 Angstroms.

Materials that can be used to form the fine particle film include, for example, Pd, Pt, Ru, Ag,
Au, Ti, In, Cn, Cr, Fe, Zn, Sn, T
a, W, Pb and other metals, PdO, Sn
Oxides such as O ₂ , In ₂ O ₃ , PbO, Sb ₂ O ₃ , HfB 2, ZrB 2, LaB 6, Ce
Borides such as B6, YB4, GdB4, etc., TiC, ZrC, HfC, TaC, SiC, WC
Such as TiN, ZrN, HfN
And the like, semiconductors such as Si and Ge, carbon, and the like, and are appropriately selected from these.

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

The conductive thin film 1104 and the device electrode 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 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, it is shown in a film form 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, polycrystal graphite, and amorphous carbon, or a mixture thereof, and has a film thickness of 500 [Å] or less, but 300 [Å] or less. Is more preferred.

Since it is difficult to accurately show the actual position and shape of the thin film 1113, it is schematically shown in FIG. Also, in the plan view (a), the thin film 11
13 shows a device in which a part of the device 13 is removed.

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 was 1000 [angstrom], and the electrode interval L was 2 [micrometer].

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

Next, a description will be given of a method of manufacturing a suitable flat surface conduction electron-emitting device.

FIGS. 12A to 12D are cross-sectional views for explaining the manufacturing process of the surface conduction electron-emitting device, and the notation of each member is the same as that in FIG.

1) First, as shown in FIG. 12A, device electrodes 1102 and 1103 are formed on a substrate 1101.

Before forming, 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. ). 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.

In formation, 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 whose main element is a material of fine particles used for the conductive thin film (specifically, Pd is used as a main element in the present embodiment. In the embodiment, coating is performed. As the method, a dipping method was used, but other methods such as a spinner method and a spray method may be used.)

As a method of forming a conductive thin film made of a fine particle film, a method 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 Method may be used.

3) Next, as shown in FIG. 14C, a forming power supply 1110 supplies the device electrodes 1102 and 1102 with each other.
3, an appropriate voltage is applied, and an energization forming process is performed to form the electron-emitting portion 1105.

The 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 change the structure into a structure suitable for emitting electrons. This is the process that causes A portion of the conductive thin film made of a 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. 13 shows an example of an appropriate voltage waveform applied from the forming power supply 1110 in order to explain the energization method in more detail. When forming a conductive thin film made of a fine particle film, a pulse-like voltage is preferable. In the case of this embodiment, a triangular wave pulse having a pulse width T1 is continuously generated at a pulse interval T2 as shown in FIG. Was applied. At that time, the peak value Vpf of the triangular wave pulse was sequentially increased. In addition, monitor pulses Pm for monitoring the state of formation of the electron-emitting portion 1105 were inserted at appropriate intervals between the triangular-wave pulses, and the current flowing at that time was measured by the ammeter 1111.

In the embodiment, for example, in a vacuum atmosphere of about 10 −5 [Torr], for example, the pulse width T1 is 1 [millisecond], the pulse interval T2 is 10 [millisecond], and the peak value Vpf is The voltage was increased by 0.1 [V] for each pulse. Then, the monitor pulse Pm was inserted at a rate of one every time five triangular waves were applied. The monitor pulse voltage Vpm was set to 0.1 [V] so as not to adversely affect the forming process. Then, when the electric resistance between the device electrodes 1102 and 1103 becomes 1 × 10 6 [ohm], that is, the current measured by the ammeter 1111 at the time of application of the monitor pulse is 1 × 10 −7 [A When the following conditions were reached, the energization related to the forming process was terminated.

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

4) Next, as shown in FIG. 12D, an appropriate voltage is applied between the element electrodes 1102 and 1103 from the activating power supply 1112 to perform the energizing activation process, and the electron emission characteristics are obtained. Make improvements.

The energization activation process is a process of energizing the electron-emitting portion 1105 formed by the energization forming process under appropriate conditions and depositing carbon or a carbon compound in the vicinity thereof (in the figure). Shows a deposit made of carbon or a carbon compound 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 the fourth power to 1
By applying a voltage pulse periodically in a vacuum atmosphere within the range of 0 to the fifth power [Torr], carbon or a carbon compound originating from an organic compound existing in the vacuum atmosphere is deposited. The deposit 1113 is any of single crystal graphite, polycrystal graphite, and amorphous carbon, or a mixture thereof, and has a thickness of 500.
[Angstrom] or less, more preferably 300 [angstrom] or less.

FIG. 14A shows an example of an appropriate voltage waveform applied from the activation power supply 1112 in order to explain the energization method in more detail. In the present embodiment, the energization activation process is performed by periodically applying a rectangular wave of a constant voltage. 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,
When the design of the surface conduction electron-emitting device is changed, it is desirable to appropriately change the conditions accordingly.

An anode electrode 1114 shown in FIG. 12D is used to capture an 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 (FIG. 12D). 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 process, and the activation power supply 1112 is monitored.
Control the operation of. An example of the emission current Ie measured by the ammeter 1116 is shown in FIG.
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. If the design of the surface conduction electron-emitting device is changed, the conditions should be changed accordingly. desirable.

As described above, the planar type surface conduction electron-emitting device shown in FIG. 12E was manufactured. (Vertical type surface conduction electron-emitting device) Next, another typical structure of a surface conduction electron-emitting device in which an electron-emitting portion or its periphery is formed of a fine particle film, that is, the structure of a vertical surface conduction electron-emitting device Will be described.

FIG. 15 is a schematic cross-sectional view for explaining the basic structure of the 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 described above is that one of the device 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
For 204, the materials listed in the description of the planar type can be similarly used. For the step forming member 1206, an electrically insulating material such as SiO ₂ is used.

Next, a method of manufacturing a vertical surface conduction electron-emitting device will be described. FIGS. 16A to 16F are cross-sectional views for explaining a manufacturing process.
Same as 6.

1) First, as shown in FIG. 16A, an element electrode 1203 is formed on a substrate 1201.

2) Next, as shown in FIG. 17B, an insulating layer for forming a step forming member is laminated. The insulating layer may be formed by stacking, for example, SiO ₂ 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. 13C, an element electrode 1202 is formed on the insulating layer.

4) Next, as shown in FIG. 17D, 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. 17E, 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, similarly to the case of the flat type, the energization forming process is performed to form an electron emission portion (the same process as the flat type energization forming process described with reference to FIG. 12C). Just do it.)

7) Next, similarly to the case of the above-mentioned flat type, an energization activation process is performed to deposit carbon or a carbon compound in the vicinity of the electron emission portion (the flat type energizing described with reference to FIG. The same processing as the activation processing may be performed.)

As described above, the vertical surface conduction electron-emitting device shown in FIG. (Characteristics of the surface conduction electron-emitting device used in the display device)
The device configuration and manufacturing method of the planar and vertical surface conduction electron-emitting devices have been described. Next, the characteristics of the devices used in the display device will be described.

FIG. 17 shows typical examples of (emission current Ie) versus (device applied voltage Vf) characteristics and (device current If) versus (device applied voltage Vf) characteristics of the device used in the display device. . Note that the emission current Ie is significantly smaller than the element current If, and it is difficult to show the same current on the same scale.
Since these characteristics are changed by changing design parameters such as the size and shape of the element, the two graphs are shown in arbitrary units.

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

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

That is, the non-linear element has a clear threshold voltage Vth with respect to the emission current Ie.

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

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

Because of the above characteristics, the surface conduction electron-emitting device 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 Vt according to a desired light emission luminance.
h or higher, 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, by utilizing the second characteristic or the third characteristic, the light emission luminance can be controlled, so that gradation display can be performed. (Structure of a multi-electron beam source in which a large number of elements are arranged in a simple matrix) Next, the structure of a multi-electron beam source in which the above-mentioned surface conduction electron-emitting devices are arranged on a substrate and arranged in a simple matrix will be described.

FIG. 18 is a plan view of the multi-electron beam source used for the display panel of FIG. On the substrate, surface conduction type emission devices similar to those shown in FIG. 11 are arranged.
And the column-directional wiring electrodes 1004 are arranged in a simple matrix. 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. 19 is a sectional view taken along the line BB '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. 20 shows a display panel using the above-described surface conduction electron-emitting device as an electron beam source so that image information provided from various image information sources such as television broadcasting can be displayed. It is a figure for showing an example of the constituted display.

In the figure, reference numeral 2100 denotes a display panel;
101 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 a CPU, 2107 is an image generation circuit,
2108, 2109 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 this display device
For example, when a signal containing both video information and audio information such as a television signal is received, the audio is reproduced at the same time as the display of the video, but the audio information is not directly related to the features of the present invention. Descriptions of circuits, speakers, and the like relating to reception, separation, reproduction, processing, storage, and the like 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. A TV signal (for example, a so-called high-definition TV such as the MUSE system) composed of a larger number of scanning lines 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.

Like the TV signal receiving circuit 2113,
The type of TV signal to be received is not particularly limited,
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 taking in an image signal supplied from an image input device such as a TV camera or an image reading scanner.
4 is output.

An image memory interface circuit 2110 is a circuit for taking in an image signal stored in a video tape recorder (hereinafter abbreviated as VTR). The taken image signal is output to a decoder 2104.

An image memory interface circuit 2109 is a circuit for taking in an image signal stored in a video disk. The taken image signal is output to a decoder 2104.

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.
Output to 104.

The input / output interface circuit 210
Reference numeral 5 denotes a circuit for connecting the display device to an external computer, a computer network, or an output device such as a printer. Image data and text
It is possible not only to input and output graphic information, but also to input and output control signals and numerical data 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 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 image processing And other circuits necessary for generating an image.

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

The CPU 2106 mainly carries out 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 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 the image signal to be displayed, and the display frequency, the scanning method (for example, interlaced or non-interlaced), the number of scanning lines per screen, and the like 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 the 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 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, a joystick, a barcode reader,
Various input devices such as a voice recognition device can be used.

Also, the decoder 2104 has the
2 to 3113 are circuits for inversely converting various image signals input from 3113 to three primary color signals or a luminance signal and an I signal and a Q signal. It is to be noted that the decoder 2104 desirably includes an image memory therein, as indicated by a dotted line in FIG. This includes, for example, the MUSE method,
This is for handling a television signal that requires an image memory when performing the inverse conversion. 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 provided by 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 driving power supply (not shown) for the display panel is output to the driving circuit 2101.

[0208] Also, as a signal related to the display panel driving method, a signal for controlling, for example, a screen display frequency and a scanning method (for example, interlace or non-interlace) is output to the drive circuit 2101.

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

The drive circuit 2101 is a circuit for generating a drive signal to be applied to the display panel 2100, and includes 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 unit has been described above.
In the present display device, the image information input from various image information sources can be displayed on the display panel 2100 with the configuration illustrated in FIG.

That is, various image signals such as television broadcasts are inversely converted by the decoder 2104, appropriately selected by the multiplexer 2103, and input to the drive circuit 2101. On the other hand, the display panel controller 2102 generates a control signal for controlling the operation of the driving circuit 2101 according to the image signal to be displayed. The driving circuit 2101 applies a driving signal to the display panel 2100 based on the image signal and the control signal.

Thus, the display panel 2100
Displays an image. A series of these operations is C
It is totally controlled by the PU 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, rotating, moving, edge emphasizing, thinning out, and interpolating the displayed image information. , Color conversion,
It is also possible to perform image processing such as image aspect ratio conversion and the like, and image editing such as synthesis, deletion, connection, replacement, and fitting. Although not specifically 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 is possible to combine functions such as game machines with one unit,
Extremely wide range of applications for industrial or consumer use.

FIG. 20 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 beam source, and it goes without saying that the present invention is not limited to this. . For example, among the components in FIG. 20, 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 to a videophone, it is preferable to add a television camera, an audio microphone, a lighting device, a transmission / reception 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 beam source can be easily thinned, so that the depth of the entire display device can be reduced. In addition, the display panel using the surface conduction electron-emitting device as the electron beam source is easy to enlarge the screen, has high brightness, and has excellent viewing angle characteristics. It is possible to display well.

[0218]

According to the first configuration of the present invention, it is possible to display an image having good tone reproduction characteristics irrespective of the saturation phenomenon of the phosphor. Further, by performing the correction for each emission color, it is possible to display an image having good color reproduction characteristics.

According to the second configuration of the present invention, even when the display device receives a plurality of types of input signals such as a TV signal and a PC image signal, it has good tone reproduction and color reproduction characteristics. Image display becomes possible.

According to the third configuration of the present invention, even when the display device performs so-called ABL control for lowering the average luminance of the entire screen even if the peak luminance is large in order to suppress power consumption, good gradation can be obtained. Image display having reproduction and color reproduction characteristics can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a driving circuit of a surface conduction electron emission display (SED) panel.

FIG. 2 NTSC-RGB decoder section

FIG. 3 is a timing generator.

FIG. 4 is an analog processing section.

FIG. 5 is a time chart for explaining an operation of a driving circuit of a surface conduction electron emission display (SED) panel.

FIG. 6 is a graph showing gamma restoring characteristics;

FIG. 7 is a graph showing emission luminance characteristics of the SED panel.

FIG. 8 is a block diagram of an input signal selector.

FIG. 9 is a perspective view of an SED display panel.

FIG. 10 is an arrangement diagram of a phosphor matrix.

FIG. 11 is a plan view and a cross-sectional view of a surface conduction electron-emitting device.

FIG. 12 is a manufacturing process diagram of a surface conduction electron-emitting device.

FIG. 13 is a diagram of a forming voltage waveform.

FIG. 14 is an activation voltage waveform and emission current waveform diagram.

FIG. 15 is a sectional view of a vertical surface conduction electron-emitting device.

FIG. 16 is a manufacturing process diagram of a vertical surface conduction electron-emitting device.

FIG. 17 is a graph showing emission current characteristics of a surface conduction electron-emitting device.

FIG. 18 is an electron source using simple matrix wiring.

FIG. 19 is a sectional view taken along line BB ′ of the electron source formed by simple matrix wiring.

FIG. 20 is a block diagram of a surface conduction electron-emitting display system.

FIG. 21 is a plan view of a conventional surface conduction electron-emitting device.

FIG. 22 is a sectional view of a conventional field emission electron-emitting device.

FIG. 23 is a sectional view of a conventional MIM type electron-emitting device.

FIG. 24 is a matrix arrangement diagram of a conventional MIM type electron-emitting device.

[Explanation of symbols]

 P1 NTSC-RGB decoder section P2 Timing generation section P3 Analog processing section P2000 Display panel P3000 Row direction driving means P1101, P1107 Shift register 1001 Electron source substrate 1005 Rear plate 1006 Frame 1010 Face plate 1101 Substrate 1102, 1103 Element electrode 1104 Conductivity Thin film 1105 Electron emission unit

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 5C058 AA18 AB01 BA04 BA13 BB03 BB05 BB12 BB14 5C080 AA08 AA18 BB05 CC03 DD03 DD30 EE29 EE30 FF12 GG02 GG08 GG09 GG12 JJ02 JJ03 JJ04 JJ05 JJ06

Claims (12)

[Claims] An electron-emitting device; a phosphor that emits light by receiving electrons emitted from the electron-emitting device; an image signal converting unit that converts an input image signal to output a converted image signal; A modulating means for modulating an electron beam emitted from the electron-emitting device based on a signal, wherein the image signal converting means gamma-corrects the original signal for a cathode ray tube (CRT). The input image signal is restored to the original signal, and the restored original signal is corrected by correcting the non-linearity of the electron beam intensity versus the phosphor emission luminance to make the electron beam intensity vs. the phosphor emission luminance characteristic a straight line. An image display device that converts the image data into the converted image signal and outputs the converted image signal. 2. An image signal conversion device comprising: an image determination unit configured to determine a type of the input image signal; and a modulation range limitation unit configured to limit a modulation range of the electron beam intensity based on an output of the image determination unit. 2. The image display device according to claim 1, wherein the means converts the input image signal and outputs a converted image signal in the modulation range. 3. An image processing apparatus comprising: an average value detecting unit configured to detect an average value of the amplitude of the input image signal; and an average modulating unit configured to modulate the electron beam based on the average value. The input image signal gamma-corrected for a cathode ray tube (CRT) is restored to the original signal, and the average value of the original signal is corrected for the non-linearity of the electron beam intensity versus the phosphor emission luminance. 3. The image display device according to claim 1, wherein the image display device converts the electron beam intensity to the converted image signal that makes the phosphor emission luminance characteristic a straight line and outputs the converted image signal. 4. The apparatus according to claim 1, wherein said input image signal is a color signal, and said image signal conversion means converts said input image signal for each color signal and outputs a converted image signal. Image display device. 5. The image processing apparatus according to claim 2, wherein the input image signal is a color signal, and the image signal conversion unit converts the input image signal for each color signal and outputs a converted image signal. 3. The image display device according to any one of 3. 6. The apparatus according to claim 3, wherein said input image signal is a color signal, and said image signal converting means converts said input image signal for each color signal and outputs a converted image signal. Image display device. 7. The image signal conversion means according to claim 2, wherein said image signal conversion means includes a type conversion table memory for generating said converted image signal from said input image signal for each type of said input image. An image display device according to any one of the above. 8. The image signal converting means includes an average value conversion table memory for generating the converted image signal from the second input image signal using the average value as a second input image signal. The image display device according to claim 3, wherein 9. The image display device according to claim 1, wherein said electron-emitting device is a cold cathode device. 10. The image display device according to claim 9, wherein said cold cathode device is a surface conduction type emission device. 11. An electron-emitting device, a phosphor that emits light by receiving electrons emitted from said electron-emitting device, image signal conversion means for converting an input image signal and outputting a converted image signal, and said converted image A modulating means for modulating an electron beam emitted from the electron-emitting device based on a signal, wherein the image signal converting means converts a signal by the image signal converting means into an original signal. The input image signal obtained by correcting the input image signal for a cathode ray tube (CRT) so as to be closer to the original signal, and further correcting the signal corrected to be closer to the original signal. The further correction is performed when the drive signal based on the signal obtained by correcting the signal so as to be close to the original signal is input to the electron-emitting device. An image display device, characterized in that corrects the characteristics of the emission luminance of the phosphor caused me. 12. When a driving signal based on a signal obtained by correcting the signal so as to be close to the original signal is input to the electron-emitting device, the phosphor generated by electron emission based on the driving signal with respect to the driving signal. 12. The device according to claim 11, wherein the correction of the characteristic of the light emission luminance is a correction of the characteristic of the intensity of the electron beam emitted when the drive signal is input to the electron emission element versus the phosphor light emission luminance. Image display device.