JPH08331490A - Image display device - Google Patents

Abstract

PURPOSE: To provide an image display device with which the luminance of emitted light can be increased without increasing a voltage to be impressed on an electron source or a voltage for accelerating electrons. CONSTITUTION: A polarity is electrically switched corresponding to a switch signal from a switching circuit 5, and two rows of a display panel 12 are simultaneously selected corresponding to a scan signal outputted by a scanning row selection circuit 7. Corresponding to a video signal outputted through an MOS- FET gate 11 for which the polarity of that output signal is switched by a switching circuit 10, elements in the column direction of the display panel 12 are driven. In this case, the electric polarities of the scan signal and video signal are made mutually different so that a phosphor corresponding to one display picture element of the display panel 12 can be driven and emitted by the electrons discharged from plural electron discharging elements.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device using a plurality of surface conduction electron-emitting devices as electron sources and arranging a plurality of these devices on a two-dimensional plane.

[0002]

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

As an example of the FE type, for example, WP Dyke
& W. W. Dolan, “Field emission”, Advance in Elec
tron Physics, 8, 89 (1956) or CA Spindt,
“Physical Properties of thin-film field emission
catheodes with molybdenumcones ”, J. Appl. Phys.,
47, 5248 (1976) and the like are known.

Further, as an example of the MIM type, for example, C.I.
A. Mead, “Operation of tunnel-emission Devices,
J. Appl. Phys., 32,646 (1961) and the like are known.

As the surface conduction electron-emitting device, for example, MI Elinson Radio Eng. Electron Phys., 10,
1290. (1965) and other examples described later are known.

The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs in a small-area thin film formed on a substrate by passing a current in parallel with the film surface. As the surface conduction electron-emitting device, the above-mentioned Elison (Elison
nson) et al. using a SnO2 thin film,
By thin film [G. Dittmer: “Thin Solid Films” ,,
9,317 (1972)] and In2O3 / SnO2 thin film [M. Hartwell and CG Fonstad: "IEEE Trans. ED
Conf. ”, 519 (1975)] and carbon thin films [Hiraki Araki et al .: Vacuum, Vol. 26, No. 1, 22 (198).
3)] etc. have been reported.

As a typical example of the device configuration of these surface conduction electron-emitting devices, a plan view of the device by M. Hartwell et al. Is shown in FIG. In the figure, 3001 is a substrate, and 3004 is a conductive thin film made of metal oxide formed by sputtering. The conductive thin film 3004 is formed in an H-shaped plane shape as shown in the drawing. An electron-emitting portion 3005 is formed by subjecting this conductive thin film 3004 to an energization process called energization forming described later. The interval L in the figure is set to 0.5 to 1 [mm], and W is set to 0.1 [mm]. Further, for convenience of illustration, the electron emitting portion 3005 is shown as a rectangular shape in the center of the conductive thin film 3004, but this is a schematic one, and the actual position and shape of the electron emitting portion are faithfully expressed. It doesn't mean that.

In the surface conduction electron-emitting device described above including the device by M. Hartwell et al., The electron-emitting portion 3005 is formed by subjecting the conductive thin film 3004 to an energization process called energization forming before the electron emission. It was common to do. That is, the energization forming is performed by applying a constant DC voltage or a DC voltage that is boosted at a very slow rate of, for example, about 1 V / min to both ends of the conductive thin film 3004 to conduct electricity, and the conductive thin film 3
That is, 004 is locally destroyed, deformed, or altered to form an electron emitting portion 3005 having a high electrical resistance. A crack occurs in a part of the conductive thin film 3004 which is locally destroyed, deformed or altered. After this energization forming, the conductive thin film 30 is formed.
When an appropriate voltage is applied to 04, electrons are emitted near the crack.

The surface conduction electron-emitting device described above has an advantage that a large number of devices can be formed over a large area because it has a simple structure and is easy to manufacture among cold cathode devices. Therefore, for example, JP-A-64-31 by the applicant of the present application
As disclosed in Japanese Patent No. 332, a method for arranging and driving a large number of elements has been studied.

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

Particularly, as an application to an image display device, for example, USP 5,066,883 by the applicant of the present application and JP-A-2-25
As disclosed in Japanese Patent No. 7551 and Japanese Patent Application Laid-Open No. 4-28137, an image display device using a combination of a surface conduction electron-emitting device and a phosphor that emits light when irradiated with an electron beam has been studied. An image display device using such 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, 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, even compared with liquid crystal display devices that have become popular in recent years.

FIG. 22 is a diagram showing a positional relationship between an electron-emitting device and a phosphor in a display device using a conventional surface conduction electron-emitting device.

As shown, the phosphor 5000 is applied to the inside of the face plate 5001. The electron-emitting device 5004 is sandwiched between a pair of electrodes 5005, and when a voltage of a certain value or more is applied between the pair of electrodes 5005, electrons are emitted from the electron-emitting portion 5006. The electrons emitted in this way irradiate the phosphor 5000 in an electron orbit 5003 as shown in the figure. At this time, the acceleration voltage for accelerating the electrons emitted from the electron emitting portion 5006 toward the face plate 5001 and irradiating the phosphor 5000 is Va [V], and the electron emitting portion 5
The voltage applied to the electrode 5005 in order to emit electrons from 006 is Vf [V].

Conventionally, as a method of increasing the brightness of such a display device, the amount of electrons Ie [A] emitted from the electron emission portion 5006 is increased, or the acceleration for accelerating the electrons irradiating the phosphor 5000 is accelerated. A method of increasing the voltage Va [V] is adopted. In order to increase the emitted electron amount Ie, the voltage V applied between the electrodes 5005 is
f [V] may be increased.

[0015]

The inventors of the present application have tried surface-conduction type emission devices having various materials, manufacturing methods and structures, including those described in the above-mentioned prior art. further,
We have conducted research on a multi-electron beam source in which a large number of surface conduction electron-emitting devices are arranged, and an image display device to which this multi-electron beam source is applied. An example of this is shown in FIG. FIG. 23 is a diagram showing a multi-electron beam source in which these surface conduction electron-emitting devices are arranged in a matrix.
Here, a large number of surface conduction electron-emitting devices are two-dimensionally arranged and these devices are wired in a matrix as shown in the drawing.

In the figure, 4001 schematically shows a surface conduction electron-emitting device, 4002 shows row-direction wiring, and 4003 shows column-direction wiring. These row-direction wirings 4002 and column-direction wirings 4003 actually have finite electric resistance, but they are shown as wiring resistances 4004 and 4005 in the figure. The wiring method as described above is hereinafter referred to as simple matrix wiring. Incidentally, for convenience of illustration, this multi-electron source is shown as a 6 × 6 matrix, but the scale of the matrix is not limited to this, and in the case of a multi-electron beam source for an image display device, for example, it is desired. The elements are arranged and wired in a number sufficient to display the image.

In the multi-electron beam source in which the surface conduction electron-emitting devices are wired in a simple matrix as described above, appropriate electric signals are applied to the row-direction wirings 4002 and the column-direction wirings 4003 in order to output a desired electron beam. For example, in order to drive the surface conduction electron-emitting device of any one row in the matrix, the selection voltage Vs is applied to the row-direction wiring 4002 of the selected row, and simultaneously the row-direction wiring 4002 of the non-selected row is applied. Applies the non-selection voltage Vns. In synchronization with this, a drive voltage Ve for outputting an electron beam is applied to the column-direction wiring 4003. According to this method, if the voltage drop due to the wiring resistances 4004 and 4005 is ignored,
The surface conduction electron-emitting device of the selected row has (Ve-Vs)
The voltage of (Ve-Vns) is applied to the surface conduction electron-emitting devices of the non-selected rows. If these voltage values Ve, Vs, and Vns are set to appropriate magnitudes, an electron beam with a desired intensity should be output from only the surface conduction electron-emitting devices of the selected row, and the column-direction wirings are also provided. If different drive voltages Ve are applied, electron beams of different intensities should be output from the elements of the selected row. Further, since the response speed of the surface conduction electron-emitting device is high, if the length of time for applying the drive voltage Ve is changed, the length of time for outputting the electron beam should be changed.

Therefore, the multi-electron beam source in which the surface conduction electron-emitting devices are wired in a simple matrix has various applications. For example, if an electric signal according to image information is appropriately applied, it can be used as an electron source for an image display device. It can be preferably used.

In order to increase the brightness in an image display device using such a surface conduction electron-emitting device as an electron beam source, the voltage value applied between the electrodes 1005 of FIG. There is a method of increasing the amount of electrons Ie generated. However, when this method is adopted, a large current flows in the row-direction wiring 4002 of the selected row, the voltage effect by the wiring resistance 4004 becomes large, and there is a problem in that the brightness is not constant on the screen. Further, there is a method of increasing the acceleration voltage Va of the electrons with which the phosphor 1000 is irradiated in order to increase the displayed brightness. However, if the accelerating voltage is increased to a predetermined value or higher, the electron emission unit 1006
Since this causes dielectric breakdown between the phosphor 1000 and the phosphor 1000, this method is also limited.

The present invention has been made in view of the above conventional example, and provides an image display device capable of increasing the emission brightness without increasing the voltage applied to the electron source or the voltage for accelerating the electrons. The purpose is to do.

Another object of the present invention is to provide an image display device capable of increasing the emission brightness by causing one phosphor to emit light by electrons from a plurality of electron sources.

Another object of the present invention is to provide an image display device in which even if a defect occurs in one electron source, it can be compensated by another electron source.

Another object of the present invention is to easily perform interlaced scanning for display by changing the voltage direction applied to the electron source during the first display scanning and the second display scanning. It is to provide an image display device capable of

[0024]

In order to achieve the above object, the image display device of the present invention has the following configuration.
That is, a multi-electron beam source in which a surface conduction electron-emitting device having a pair of electrodes and an electron-emitting portion is connected in a plurality of rows to form a matrix, and light is emitted by electrons emitted from the electron beam source. In the image display device including the phosphor, the scanning row selecting means for selecting any two rows out of a plurality of rows of the surface conduction electron-emitting device included in the multi-electron beam source, and the scanning row selecting means. Scan drive means for applying a drive signal to two rows of the selected surface conduction electron-emitting device, and polarity inversion means for inverting the voltage value of each drive signal applied to the pair of electrodes at predetermined intervals. Have and.

[0025]

In the above structure, any two rows of the surface conduction electron-emitting devices included in the multi-electron beam source are selected, and a drive signal is applied to the two rows of the selected surface conduction electron-emitting devices. Apply. Then, by inverting the voltage value of each drive signal applied to the pair of electrodes every predetermined period, one phosphor is driven by electrons emitted from a plurality of surface conduction electron-emitting devices to emit light. .

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. <First Embodiment> FIG. 1 is a block diagram showing the arrangement of an image display apparatus according to an embodiment of the present invention. In the first embodiment, a case where interlaced scanning is not performed will be described.

The sync separation circuit 14 separates the sync signal of the NTSC signal s1 from the video signal. This sync separation circuit 14
The sync signal separated by 1 is sent to the timing control circuit 3, and the video signal is sent to the signal processing unit 1. The signal processing unit 1 performs signal processing such as A / D conversion on the video signal, and then sends this to the modulation signal generation unit 2. The modulation signal generator 2 serial-parallel converts the video signal for one line and outputs it as a pulse width modulation signal s4 to the gate of the MOS-FET 11.

The switching circuit 4 is a circuit for inverting the polarity of the video signal s5 output from the gate 11. Electron emitting device 13 in display panel 12
Is a pair of electrodes 5 facing each other, as shown in FIG.
The structure is such that the electron emitting portion 53 is sandwiched between 6 and 57. By reversing the polarity of the voltage applied to the pair of electrodes 56, 57, the electron-emitting device 13 emits electrons in the right direction of the drawing, as shown in FIG. 3, or vice versa. Can be emitted to the left.
The control signal s2 from the timing control circuit 3 is a signal for controlling the timing of inverting the polarity of the video signal s5. Further, 10 is a switch for inverting the polarity of the video signal s5, which is switched in conjunction with a switch 8 described later.

The switching circuit 5 is a circuit for inverting the polarity of the scanning signal s6. The pulse generator 6 is
The pulse signal s7 having the same polarity is continuously generated. When the pulse signal s7 from the pulse generator 6 passes through the inverter 9 by switching the switch 8 by the signal s3 from the timing control circuit 3, the polarity of the pulse signal s7 is inverted, and if it does not pass, it is not inverted. . The pulse signal s7 that has passed through the switching circuit 5 is the scanning signal s for which the row to be display-driven is selected by the scanning row selection circuit 7.
6 is sent to the display panel 12.

FIG. 2 shows the display panel 1 of this embodiment.
It is a figure for demonstrating the structure of 2.

The electron-emitting device 13 has two electrodes 56 and 57 facing each other and an electron-emitting portion 53 sandwiched between these electrodes 56 and 57. Between these electrodes 56 and 57,
Electrons are emitted from the electron emitting portion 53 by applying a voltage equal to or higher than a certain value. As shown in the figure, the electrode 57 is connected to the column direction wiring 54 and has the same potential as the potential of the video signal s5. The electrode 56 is connected to the row-direction wiring 55, and has the same potential as the scanning signal s6 while the line is selected and the display scanning is performed. Here, if the polarities of the video signal s5 and the scanning signal s6 are reversed, the electrodes 56, 5
The polarity of the potential applied to 7 is also inverted. Therefore, the polarity of the voltage applied to the electron emitting portion 53 is also inverted. When the polarity of the voltage applied to the electron emitting portion 53 is reversed in this way, the trajectory of the electrons emitted from the electron emitting portion 53 changes as shown in FIG.

FIG. 3 is a sectional view showing the structure of one electron-emitting device when it is cut along the section A in FIG.

On the inside of the face plate 101, phosphors 110 and 111 are applied as shown in the figure. The electrodes 56 and 57 are provided in the row direction wiring 55 and the column direction wiring 5, respectively.
4 is connected to a voltage higher than a certain value (for example, Vf
When [v]) is applied, electrons are emitted from the electron emitting portion 53. When electrons are emitted, the face plate 101
Electrons are accelerated in the face plate direction by the voltage Va [V] applied between the electron emitting portion 53 and the electron emitting portion 53, and the phosphor 110 or 111 of the face plate 101 is irradiated with the electrons. At this time, the electron does not go straight up along the central axis 100 but goes along the electron orbit 102 or the electron orbit 103. Now, when the voltage Vf is applied so that the electrode 56 has a negative polarity and the electrode 57 has a positive polarity (solid line in the figure).
Means that the electrons emitted from the electron emitting portion 53 have an electron orbit 1
Proceed on the orbit indicated by 03 (solid line). On the contrary, when the voltage Vf is applied so that the electrode 56 has the positive polarity and the electrode 57 has the negative polarity (dotted line in the figure), the orbit of the electron emitted from the electron emitting portion 53 is the electron orbit 102 (dotted line). ). The distance Lef between the central axis 100 and the electron landing position at this time can be calculated by the following equation (1).

Lef = 2 × K × Lh × SQRT (Vf / Va) (1) where Lh [m] is the electron-emitting device 13 and the phosphor 110.
Alternatively, it indicates the distance from 111, and K is the electron-emitting device 1
It is a constant determined by the type and shape of 3. Also, SQR
T (Vf / Va) indicates the square root of Vf / Va.

Next, the operation of the display device of this embodiment will be described with reference to FIG.
Will be explained.

NT input from, for example, a TV image receiving circuit
The SC signal is separated by the sync separation circuit 14 into a sync signal and a video signal. The synchronization signal is sent to the timing control circuit 3, and the video signal is sent to the signal processing unit 1. Signal processing unit 1
Then, R, G, and B color demodulation and A / D conversion are performed, and a digital video signal is sent to the modulation signal generation unit 2. In this modulation signal generation unit 2, data of one line of the video signal sent from the signal processing unit 1 is serial-parallel converted and sent as a pulse width modulation signal s4 to the gate of the MOS-FET 11.

The switching circuit 4 is a circuit for inverting the polarity of the video signal s5. The switch switching signal s2 is input from the timing control circuit 3 to the switch 10, and the switch 10 is switched in accordance with the switching signal s2.
Connection is switched between the a terminal and the b terminal. Now, when the switch 10 is connected to the terminal a, the negative video signal s5 is sent to the display panel 12, and conversely, when the switch 10 is connected to the terminal b, the positive video signal s5 is sent. Will be output. The switching between the positive polarity and the negative polarity is performed every horizontal synchronization period (1H).

The switching circuit 5 is a circuit for inverting the polarity of the scanning signal s6 input to the display panel 12. First, the pulse generator 6 generates a pulse signal s7 having the same polarity (for example, positive polarity) and a 1H cycle.
The switch 8 is switched every 1H by a switch switching signal s3 from the timing control circuit 3. That is, when the switch 8 is connected to the terminal c, the pulse signal s7 directly passes through the switching circuit 5 and is input to the scanning row selection circuit 7. On the other hand, switch 8 has terminal d
When the pulse signal s7 is connected to the scanning line selection circuit 7, the polarity of the pulse signal s7 is inverted (becomes negative) by the inverter 9. In this way, the polarity is inverted every horizontal synchronization period, and the scanning signal s6 selected by the scanning row selection circuit 7 is sent to the selected row of the display panel 12.

In this embodiment, when an image is displayed, two consecutive rows of the display panel 12 are simultaneously selected by the scanning row selection circuit 7. The scanning signals of the same polarity flow simultaneously in these two selected rows. This will be described with reference to FIG. 2. First, two rows (wiring i, wiring j) are selected in the period 1H, and the other rows are unselected. And next 1H
2 rows (wiring j, wiring k) are selected, and the other rows are unselected. Similarly, (wiring k, wiring l), ...
Two lines (wiring m, wiring n) are selected.

Next, the operation of this embodiment will be described with reference to the timing chart of FIG. The symbols in the figure are the same as those in FIG.

The video signal of the NTSC signal s1 is subjected to signal processing by the signal processing section 1 and the bias signal generation section 2 to become a pulse width modulation signal s4. The pulse width modulation signal s4 in FIG. 4 shows a signal flowing through a certain signal line in the column direction. This pulse width modulation signal s
As the width L of 4 is longer, the time for which electrons are emitted from the electron emitting portion 53 is longer, so that the brightness of the pixel to be emitted is felt brighter. A switch switching signal s2 for switching the switching circuit 4 is generated every 1H, and the switch 10 is switched by this switch switching signal s2.

The switch switching signals s2 a and b in FIG. 4 indicate the connection state with the terminals of the switch 10. That is, the video signal s5 has a negative polarity when the switch 10 is connected to the terminal a, and the video signal s5 has a positive polarity when the switch 10 is connected to the terminal b. The state of the video signal s5 at this time is shown by the video signal s5 in FIG. The thin solid line indicating the video signal s5 is the ground potential (= 0.
[V]) is represented. The pulse width of the video signal s5 is equal to the width L of the pulse width modulation signal s4.

The pulse signal s7 output from the pulse generator 6 is also generated in the 1H cycle as described above. In this embodiment, the pulse signal s7 has a positive polarity. The signal s3 for switching the switch 8 output from the timing control circuit 3 is also generated in the 1H cycle, and thus the switch 8 is switched and connected to the terminal c and the terminal d every 1H. The c and d of the signal s3 in FIG. 4 indicate the connection state with the terminals and d of the switch 8.
As a result, the scanning signal s6 becomes 1H as shown in FIG.
Each time, the signal has the inverted polarity. In this embodiment, the display panel 12 is driven by scanning two consecutive rows at the same time, and at this time, the video signal s
5 and the scanning signal s6 must have opposite polarities.

FIGS. 5A and 5B show how the phosphor 120 is irradiated with electrons from each electron emitting portion 53 when the display device is driven as described above. It is a figure.

In this figure, when the X, Y, and Z coordinate systems are determined as shown in the display panel 12 which will be described later with reference to FIG. 9, one line of emission elements is arranged in a certain vertical direction (Y direction). 3 shows a cross section taken along the YZ plane.

The phosphor 120 is provided on the surface facing the electron emission portion 53 inside the face plate 155,
The electron emitting portion 53, the wiring i to the wiring 1, and the electrodes 56 and 57 are provided on the rear plate 154. The electrode 56 is connected to the row-direction wiring 55 (only wirings i to 1 are shown), and the electrode 57 is connected to the column-direction wiring 54. Trajectories i, j, j1, k1, k, l in FIG.
The electron trajectories by which the electrons emitted from the electron emission portion 53 reach the phosphor 120 are shown. When the electrons collide with the phosphor 120 in this manner, the phosphor 120 emits light.

With reference to FIG. 5A, how a signal in a certain field is displayed will be described.

It is assumed that the wiring i and the wiring j are selected in a certain 1H period, and the positive scanning signal s6 flows through these wirings. At this time, the negative direction video signal s5 is applied to the column-direction wiring 54. At this time, the potential of the electrode 56 becomes positive and the potential of the electrode 57 becomes negative. In this state, the electrons emitted from the electron emitting portion 53 draw the orbit i and the orbit j and are applied to the phosphor 120. The electrons emitted in this manner are transmitted to the electrodes 56 connected to the wirings i and j.
The electrons are emitted from the upper and lower two electron emitting portions 53 connected to each other to form one bright spot on the phosphor 120a.

Then, in the next 1H period, the wiring j, the wiring k
Is selected, and the negative scanning signal s6 is applied to these wirings j and k.
Is applied. At this time, the video signal s5 having a positive polarity flows through the column-direction wiring 54. That is, the potential of the electrode 56 becomes negative and the potential of the electrode 57 becomes positive. The electrons emitted from the corresponding electron emitting portion 53 emitted in this way illuminate the phosphor 120b in a trajectory j1 and a trajectory k1 to form one bright spot. Similarly, the wiring k and the wiring l in the row direction are selected, and the electrode 56 is made positive and the electrode 57 is made positive.
Is set to a negative polarity, the electrons emitted from the electron emitting portion 53 draw the orbits k and 1 and collide with the phosphor 120c to form one bright spot.

As described above, two row-direction wirings are simultaneously driven in one horizontal scanning period, and the electric field directions applied to the electron-emitting portions located above and below and connected to the row-direction wirings are mutually inverted. As a result, each electron emission unit emits electrons in two types of trajectories and irradiates the same phosphor.
As a result, each phosphor is irradiated with electrons from the electron emitting portions at the two upper and lower positions, and one bright spot is formed from the two electron emitting portions, so that the brightness of the bright spots is reduced to the normal level. It can be doubled.

Further, as shown in FIG. 5B, the electron orbit is further extended in the vertical direction of the figure so that the combination of the electron emitting portion and the phosphor is different from that of FIG. 5A. It is also possible to take. Such a change in the electron orbit is possible by changing the values of Va and Vf in the above-mentioned formula (1), that is, by increasing (Vf / Va).

<Second Embodiment> Next, as a second embodiment of the present invention, a method of displaying an NTSC signal by interlaced scanning will be described. Incidentally, this second embodiment can also be realized by the circuit of FIG. 1 similarly to the above-mentioned first embodiment. However, the switching cycle of the switches 8 and 10 in FIG. 1 is not one horizontal scanning period (1H) but one field period. Further, in this second embodiment, the same electron-emitting device as that of the above-mentioned first embodiment is used, and wiring is performed as shown in FIG.

Next, the operation of this embodiment will be described with reference to the timing chart of FIG. The symbols in the figure are the same as those in FIG.

The video signal of the NTSC signal s1 is subjected to signal processing by the signal processing section 1 and the modulation signal generation section 2 to become a pulse width modulation signal s4. This pulse width modulation signal s4 is a signal flowing through the one column-direction signal when paying attention to it. The longer the width L of the pulse width modulation signal s4, the longer the time for which electrons are emitted from the electron emitting portion 53, so that the bright spot (pixel) feels bright. The switch switching signal s2 is generated every one field period to switch the connection of the switch 10. 6A and 6B represent terminals to which the switch 10 is connected. Switch 1 now
The video signal s5 has a negative polarity when 0 is connected to the terminal a, and the video signal s5 has a positive polarity when connected to the terminal b. The state of the video signal s5 is shown in FIG. The thin solid line in the figure represents the ground potential (= 0 [V]).
The pulse width of the video signal s5 is the pulse width modulation signal s4.
Is equal to the width L of.

Further, the pulse signal s7 is generated in a 1H cycle, and in this embodiment, the pulse signal s7 has a positive polarity. The signal s3 for switching the switch 8 is generated in a cycle of one field period. Thereby, the switch 8 is switched so as to be connected to the terminal c and the terminal d every one field period. Along with this, the scanning signal s6 becomes a signal whose polarity is inverted for each field as shown in FIG. Further, in the second embodiment, the first
Similar to the embodiment, two consecutive display panels 12 are provided.
Drive rows simultaneously. Also at this time, the polarities of the video signal s5 and the scanning signal s6 must always be opposite.

7A and 7B show how electrons are emitted from each electron emitting portion 53 toward the phosphor 120 when the display device is driven at the timing shown in FIG. FIG.

7 (a) and 7 (b) are shown in FIG.
FIG. 9 is a diagram showing a cross-sectional view taken along the YZ plane along one row of the emitting devices in a certain vertical direction (Y direction) when the X, Y, Z coordinate system is determined as shown in FIG. Similar to the first embodiment described above, the phosphor 120 is provided on the surface of the face plate 155 facing the rear plate 154, and the electron emitting portion 53, the wirings i to n, and the electrodes 56 and 57 are the rear plate 154. On the surface facing the face plate 155. The electrode 56 is connected to the row-directional wiring 55 (wiring i to wiring n), while the electrode 57 is connected to the column-directional wiring 5
It is connected with 4. And orbit i to orbit n, orbit i
Each of 1 to orbit n1 shows an electron orbit with which electrons emitted from each electron emitting portion 53 irradiate the phosphor 120. In this way, when the phosphor 120 is irradiated with electrons, the phosphor 120 emits light.

FIG. 7A shows an electron orbit when displaying a certain field, and FIG. 7B shows an electron orbit when displaying the next field.

First, with reference to FIG. 7A, the manner of displaying a signal in a certain field will be described. In this field, the video signal s5 flowing through the column wiring 54 is always negative. That is, the electrodes 57 connected to the column wiring 54
The potential of is always negative. One horizontal scanning period (1
In H), it is assumed that the row-direction wiring i and the wiring j are selected, and the positive scanning signal s6 flows through these wirings i and j. That is, the potential of the electrode 56 connected to the row wiring has a positive polarity, and the potential of the electrode 57 has a negative polarity. The electrons emitted at this time are applied to the phosphor 120 in a trajectory i and a trajectory j. Thus, when the wirings i and j are selected, the electrons emitted from the electron emitting portions 53 located above and below the wirings i and j form one bright spot on the phosphor 120a. .

Then, in the next 1H period, the wiring k and the wiring l
And the scanning signal s of positive polarity is applied to these row-direction wirings 55.
6 is applied. That is, the potential of the electrode 56 connected to these row-direction wirings becomes positive, and the potential of the electrode 57 becomes negative. At this time, the electrons emitted from the electron emitting portions 53 located above and below the wirings k and l are drawn on the phosphor 120b in the orbits k and l. Similarly, after selecting the wiring m and the wiring n, the electrons emitted from the electron emitting portions 53 located above and below the wirings m and n are emitted so as to draw the trajectories m and n, and the phosphor 120c. A bright spot is formed on the top. In this manner, the phosphors 120 are sequentially made to emit light, so that an image can be displayed by performing interlaced scanning every other row.

Next, with reference to FIG. 7B, the manner of displaying the signal of the next field will be described. In this field, the video signal s5 flowing through the column wiring 54 is always positive. That is, the potential of the electrode 57 connected to the column wiring is always positive. In a certain 1H period, the wiring j and the wiring k are selected, and the negative scanning signal s is applied to these wirings j and k.
Suppose 5 is flowing. That is, the potential of the electrode 56 (connected to the wiring j and the wiring k) becomes negative, and the electrode 56
Has a positive polarity. At this time, the electrons emitted from each electron emitting portion 53 sandwiched by the wirings j and k are irradiated onto the phosphor 120d in a trajectory j1 and a trajectory k1 to form one bright spot.

Then, in the next 1H period, the row-direction wiring l,
The wiring m is selected, and the negative scanning signal s6 is applied to these wirings l and m. That is, the potential of the electrode 56 (connected to the wiring 1 and the wiring m) has a negative polarity, and the potential of the electrode 57 has a positive polarity. At this time, the electrons emitted from each electron emitting portion 53 sandwiched by the wirings l and m are orbits l1 and m.
1 is drawn and the phosphor 120e is irradiated. In this way, the image of the line that was not displayed in the previous field is displayed.

Further, by changing the electron trajectories as shown in FIGS. 8A and 8B, the electron emitting portion 53 and the phosphor 120 are changed.
It is also possible to configure the combination with and so as to be different from those in FIGS. Such a change in the electron orbit can be made by changing each value of Va and Vf in the above-mentioned formula (1).

In FIG. 8A, a scanning signal s6 having a positive polarity is applied to the wirings i and l in the row direction to make the potential of the electrode 56 connected to the wiring in the row direction positive. In addition, the video signal s5 applied to the column wiring is set to have a negative polarity and the electrode 57
The potential of is negative. As a result, electrons are emitted from the electron emitting portion 53 connected to the wiring i as shown by the trajectory i, and electrons are emitted from the electron emitting portion 53 connected to the wiring 1 in the trajectory shown by the trajectory l. As a result, the phosphor 1
One bright spot is formed on 20a.

Further, as shown in FIG. 8B, wirings j and m
One bright spot can be formed on the phosphor 120c by setting the electrode 56 connected to the negative polarity to a negative polarity and setting the potential of the electrode 57 connected to the column direction wiring to a positive polarity.

Also in this case, as in the case of FIG. 7 described above, the lines not displayed in the field of FIG.
It will be displayed in the next field shown in (b).

The structure of the display panel 12 and the structure of the electron-emitting device used in the above-described embodiments will be described.

[Structure and Manufacturing Method of Display Panel 12] Next, the structure and manufacturing method of the display panel 12 of the image display apparatus applied to this embodiment will be described with reference to specific examples.

FIG. 9 is a perspective view of the display panel 12 used in this embodiment, and a part of the panel 12 is cut away to show its internal structure.

In the figure, reference numeral 1005 denotes a rear plate, which corresponds to the above-mentioned rear plate 154. 1006 is a side wall,
A face plate 1007 corresponds to the above-mentioned face plate 155. By these 1005-1007, the display panel 12
An airtight container for maintaining a vacuum inside is formed. In assembling such an airtight container, it is necessary to seal the joints of the respective members so as to maintain sufficient strength and airtightness. For example, frit glass is applied to the joints and the joints are exposed to air or nitrogen atmosphere. And 400 ~ Celsius
Sealing was achieved by firing at 500 degrees for 10 minutes or more. A method of evacuating the inside of the airtight container will be described later.

A substrate 1001 is fixed to the rear plate 1005, and N × M surface conduction electron-emitting devices 1002 are formed on the substrate 1001. (N, M
Is a positive integer of 2 or more and is appropriately set according to the target number of display pixels. For example, in a display device intended for high-definition television display, N = 3000, M
It is desirable to set a number of 1000 or more. In this example, N = 3072 and M = 1024).
The N × M surface conduction electron-emitting devices 1002 are arranged in a simple matrix by M row-direction wirings 1003 and N column-direction wirings 1004. A portion constituted by the above 1001 to 1004 is called a multi-electron beam source. Regarding the manufacturing method and structure of the multi-electron beam source,
More on this later.

In this embodiment, the multi-electron beam source substrate 1001 is fixed to the rear plate 1005 of the airtight container. However, the multi-electron beam source substrate 100 is fixed.
1 has a sufficient strength, the substrate 100 of the multi-electron beam source is used as the rear plate of the airtight container.
You may use 1 itself.

Further, a phosphor film 1008 (corresponding to the phosphor 120 of the above-mentioned embodiment) is formed on the lower surface of the face plate 1007. Since the present embodiment is a color display device, the fluorescent film 1008 is separately coated with phosphors of three primary colors of red, green and blue used in the field of CRT. For example, as shown in FIG. 10, the phosphors of the respective colors are separately applied in stripes, and a black conductive material 1010 is provided between the stripes of the phosphors of the respective colors. The purpose of providing the black conductive material 1010 is to prevent the display color from deviating even if the irradiation position of the electron beam is slightly deviated, and to prevent the reflection of external light to prevent the deterioration of the display contrast. Therefore, it is also for preventing charge-up of the fluorescent film due to the electron beam. Although graphite was used as a main component for the black conductor 1010, other materials may be used as long as they are suitable for the above purpose.

In the case of producing a monochrome display panel, a monochromatic fluorescent substance may be used for the fluorescent film 1008, and the black conductive material 1010 is not always necessary.

The rear plate 10 of the fluorescent film 1008 is also provided.
A metal back 1009 known in the field of CRTs is provided on the surface on the 05 side. The purpose of providing the metal back 1009 is to reflect a part of the light emitted from the fluorescent film 1008 by specular reflection to improve the light utilization rate and to protect the fluorescent film 1008 from the collision of negative ions. The purpose is to act as an electrode for applying an accelerating voltage, and also to act as a conductive path for electrons that have excited the fluorescent film 1008. Such a metal back 100
In No. 9, after the fluorescent film 1008 is formed on the face plate 1007, the surface of the fluorescent film is smoothed, and Al is applied thereon.
(Aluminum) was formed by vacuum vapor deposition.
The metal back 1009 is not used when a low voltage fluorescent material is used for the fluorescent film 1008.

Although not used in this embodiment, a transparent electrode made of, for example, ITO is provided between the face plate 1007 and the fluorescent film 1008 for the purpose of applying an accelerating voltage and improving the conductivity of the fluorescent film. May be provided.

Further, Dx1 to Dxm, Dy1 to Dyn and Hv
Is an electric connection terminal of an airtight structure provided for electrically connecting the display panel 12 and an electric circuit (not shown). These Dx1 to Dxm are connected to the row wiring 55 of the multi electron beam source, Dy1 to Dyn are connected to the column wiring 54 of the multi electron beam source, and Hv is electrically connected to the metal back 1009 of the face plate 1007. Has been done.

In order to evacuate the inside of the airtight container to a vacuum, after assembling the airtight container, an exhaust pipe (not shown) and a vacuum pump are connected to each other, and the inside of the airtight container is reduced to 10 −7 [T
orr]. After that, the exhaust pipe is sealed, but in order to maintain the degree of vacuum in the airtight container, a getter film (not shown) is formed at a predetermined position in the airtight container immediately before or after the sealing. . The getter film is, for example, a film formed by heating a getter material containing Ba as a main component by a heater or high-frequency heating and vapor deposition, and the inside of the airtight container is 1 × due to the adsorption action of the getter film.
10 minus 5th power or 1 × 10 minus 7th power [To
rr] vacuum is maintained.

As described above, the display panel 12 according to the embodiment of the present invention.
The basic configuration of the and its manufacturing method were explained.

Next, a method of manufacturing the multi-electron beam source used for the display panel 12 of the above embodiment will be described. The multi-electron beam source used in the image display device of the present embodiment is
There is no limitation on the material, shape, or manufacturing method of the surface conduction electron-emitting device as long as it is an electron source in which the surface conduction electron-emitting device is wired in a simple matrix. However, the inventors of the present application have found that among the surface conduction electron-emitting devices, those in which the electron-emitting portion or its peripheral portion is formed of a fine particle film have excellent electron-emitting characteristics and can be easily manufactured. Therefore, it can be said that such a multi-electron beam source is most suitable for use in an image display device having a high brightness and a large screen. Therefore, in the display panel 12 of the above embodiment, the surface conduction electron-emitting device 1002 in which the electron emitting portion 53 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 wired in a simple matrix will be described.

[Preferable Element Configuration of Surface Conduction Type Emitting Element and Manufacturing Method Thereof] A typical configuration of the surface conduction type emitting element in which the electron emitting portion or its peripheral portion is formed of a fine particle film is a plane type or a vertical type. There are two types.

<Plane Type Surface Conduction Type Emitting Element> First, the element structure of the plane type surface conduction type emitting element and its manufacturing method will be described.

11 (a) and 11 (b) are a plan view (a) and a sectional view (b) for explaining the structure of the flat surface conduction electron-emitting device.

In the figure, 1101 is a substrate, 1102 and 110.
3 is a device electrode, 1104 is a conductive thin film, 1105 is an electron emission portion formed by energization forming processing, 1113.
Indicates a thin film formed by the energization activation treatment. As the substrate 1101, for example, various glass substrates such as quartz glass and soda lime glass, various ceramics substrates such as alumina, or substrates obtained by laminating an insulating layer made of, for example, SiO2 on the above various substrates are used. it can.

Further, the device electrodes 1102 and 1103 provided on the substrate 1101 so as to face each other in parallel with the substrate surface are made of a conductive material. For example, N
i, Cr, Au, Mo, W, Pt, Ti, Cu, Pd,
A material may be appropriately selected from metals such as Ag, alloys of these metals, metal oxides such as In2 O3 --SnO2, semiconductors such as polysilicon, and the like. To form these electrodes 1102, 1103,
For example, film forming technology such as vacuum deposition and photolithography,
It can be easily formed by using a combination of patterning techniques such as etching, but it may be formed by using other methods (for example, printing techniques).

The shapes of the device electrodes 1102 and 1103 are appropriately designed according to the application purpose of the electron-emitting device.
Generally, the electrode interval L is designed by selecting an appropriate value from the range of several hundreds angstroms to several hundreds of micrometers, but it is preferable that the electrode interval L is more than several micrometers for application to a display device. It is in the range of 10 micrometers. In addition, as for the thickness d of the device electrode, an appropriate numerical value is usually selected from the range of several hundred angstroms to several micrometers. A fine particle film is used for the conductive thin film 1104. The fine particle film described here refers to a film (including an island-shaped aggregate) containing a large number of fine particles as a constituent element. When the fine particle film is microscopically examined, usually, a structure in which individual fine particles are spaced apart from each other, a structure in which the fine particles are adjacent to each other, or a structure in which the fine particles overlap each other are observed.

The particle diameter of the fine particles used for the fine particle film is in the range of several angstroms to several thousand angstroms, and the range of 10 angstroms to 200 angstroms is particularly preferable. Further, the film thickness of the fine particle film is appropriately set in consideration of various conditions as described below. That is, the device electrode 1102
Alternatively, the conditions necessary for making good electrical connection with 1103, the conditions necessary for favorably performing the energization forming described later, and the conditions necessary for setting the electric resistance of the fine particle film itself to the appropriate value described later. And so on.

Specifically, it is set within the range of several angstroms to several thousand angstroms, but the range of 10 angstroms to 500 angstroms is particularly preferable.

Materials that can be used for forming the fine particle film include, for example, Pd, Pt, Ru, Ag, and A.
u, Ti, In, Cu, Cr, Fe, Zn, Sn, T
Metals such as a, W, Pb, PdO, SnO2, In2
O3, PbO, Sb2 O3, oxides such as HfB2,
Borides of ZrB2, LaB6, CeB6, YB4, GdB4, etc., TiC, ZrC, HfC, TaC, Si
Examples thereof include carbides such as C, WC, nitrides such as TiN, ZrN, HfN, semiconductors such as Si and Ge, carbon, and the like, which are appropriately selected from these.

As described above, the conductive thin film 1104 is formed of a fine particle film, and its sheet resistance value is
It was set to fall within the range of 10 3 to 10 7 [ohm / sq].

The conductive thin film 1104 and the device electrode 11
Since 02 and 1103 are preferably electrically connected well, they have a structure in which some of them overlap each other. In the example of FIG. 11, the overlapping manner is
From the bottom, the substrate 1101, the device electrodes 1102 and 1103,
The conductive thin films 1104 are stacked in this order, but in some cases, the substrate, the conductive thin film, and the device electrodes may be stacked in this order from the bottom.

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

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

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

Since it is difficult to accurately illustrate the actual position and shape of the thin film 1113, the thin film 1113 is schematically shown in FIG. 11, and in the plan view (a), an element obtained by removing a part of the thin film 1113 is shown. Is illustrated.

The basic structure of the preferable element has been described above, but the following elements were used in the examples.

That is, soda lime glass was used for the substrate 1101, and Ni thin films were used for the device electrodes 1102 and 1103. The thickness d of these device electrodes 1102 and 1103 is 1
000 [angstrom] and the electrode interval L was 2 [micrometer]. Pd or PdO was used as the main material of the fine particle film, and the thickness of the fine particle film was about 100 [angstrom] and the width W was 100 [micrometer].

Next, a method for manufacturing a suitable flat surface-conduction type electron-emitting device will be described.

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

(1) First, as shown in FIG.
The device electrodes 1102 and 1103 are formed on the substrate 1101. In forming these device electrodes, the substrate 1101 is thoroughly washed in advance with a detergent, pure water, and an organic solvent, and then the materials for the device electrodes 1102 and 1103 are deposited.
As the method of depositing, for example, a vacuum film forming technique such as a vapor deposition method or a sputtering method may be used. Then, the deposited electrode material is patterned by using a photolithography / etching technique to form a pair of device electrodes (1102 and 1103) shown in FIG.

(2) Next, as shown in FIG.
A conductive thin film 1104 is formed.

In forming this conductive thin film 1104, first, an organic metal solution is applied to the substrate 1101 of FIG. 12A, dried, and heated and baked to form a fine particle film, and then photolithography. Patterning is performed into a predetermined shape by etching. Here, the organometallic solution is a solution of an organometallic compound whose main element is the material of the fine particles used for the conductive thin film 1104. Specifically, Pd was used as the main element in this example. Further, although the dipping method is used as the coating method in the examples, other methods such as a spinner method and a spray method may be used.

The conductive thin film 11 made of a fine particle film
As a film forming method of 04, other than the method of applying the organic metal solution used in this embodiment, for example, a vacuum vapor deposition method, a sputtering method, a chemical vapor deposition method, or the like may be used.

(3) Next, as shown in FIG. 7C, the forming power supply 1110 to the device electrodes 1102 and 11
An appropriate voltage is applied during the period 03 to perform an energization forming process to form the electron emitting portion 1105.

This energization forming treatment is performed by energizing the electroconductive thin film 1104 made of a fine particle film to appropriately destroy, deform, or alter a part of the electroconductive thin film 1104, thereby forming a structure suitable for electron emission. It is the process of changing.
Of the conductive thin film made of this fine particle film, the portion changed to a structure suitable for emitting electrons (that is, the electron emitting portion 1
In 105), appropriate cracks are formed in the thin film. Note that the electric resistance measured between the element electrodes 1102 and 1103 after the formation is significantly increased as compared with before the formation of the electron emission portion 1105.

In order to explain the energizing method for forming in more detail, FIG. 13 shows an example of an appropriate voltage waveform applied from the forming power supply 1110.

When forming the conductive thin film 1104 made of a fine particle film, a pulsed voltage is preferable, and in the case of the present embodiment, the pulse width T as shown in FIG.
One triangular wave pulse was continuously applied at a pulse interval T2. At that time, the peak value Vpf of the triangular wave pulse was sequentially increased. Also, monitor pulses Pm for monitoring the formation state of the electron emission portion 1105 are inserted between the triangular wave pulses at appropriate intervals, and the current flowing at that time is measured by the ammeter 1.
111 (FIG. 12C).

In the present embodiment, for example, in a vacuum atmosphere of about 10 −5 [torr], for example, the pulse width T1 is 1 [millisecond] and the pulse interval T2 is 10.
[Millisecond], and the peak value Vpf is set to 0.1 for each pulse.
The voltage was increased by [V]. Then, the monitor pulse Pm was inserted once every five pulses of the triangular wave were applied.
Here, the voltage Vpm of the monitor pulse Pm is 0.1 [V] so that the forming process is not adversely affected.
Set to. Then, when the electric resistance between the device electrodes 1102 and 1103 becomes 1 × 10 6 [ohm],
That is, when the monitor pulse is applied, when the current measured by the ammeter 1111 becomes 1 × 10 −7 [A] or less, the energization related to the forming process is terminated.

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

(4) Next, as shown in FIG.
From the activation power source 1112 to the device electrodes 1102 and 1103
Appropriate voltage is applied between the two to perform energization activation treatment,
The electron emission characteristics are improved.

The energization activation process is a process of energizing the electron-emitting portion 1105 formed by the energization forming process under appropriate conditions to deposit carbon or a carbon compound in the vicinity thereof. In the figure, a deposit made of carbon or a carbon compound is schematically shown as the member 1113. It should be noted that by performing such energization activation processing, the emission current at the same applied voltage can typically be increased by 100 times or more as compared with before performing this activation processing.

Specifically, it is 10 −4 or 1
By periodically applying a voltage pulse in a vacuum atmosphere within a range of 0 minus 5 [torr], carbon or a carbon compound originating from an organic compound existing in the vacuum atmosphere is deposited. The deposit 1113 is one of single crystal graphite, polycrystalline graphite, amorphous carbon, or a mixture thereof, and has a film thickness of 500.
[Angstrom] or less, more preferably 300 [Angstrom] or less.

In order to explain the energization method at this time in more detail, FIG. 14A shows an example of an appropriate voltage waveform applied from the activation power supply 1112. In this embodiment, the energization activation process is performed by periodically applying a rectangular wave having a constant voltage. Specifically, the rectangular wave voltage Vac is 14
[V], pulse width T3 is 1 [millisecond], pulse interval T
4 was set to 10 [millisecond]. The above-mentioned energization conditions are preferable conditions for the surface conduction electron-emitting device of this embodiment, and when the design of the surface conduction electron emission device is changed, it is desirable to appropriately change the conditions accordingly.

Reference numeral 1114 shown in FIG. 12 (d) is an anode electrode for trapping the emission current Ie emitted from the surface conduction electron-emitting device, to which a DC high voltage power supply 1115 and an ammeter 1116 are connected. When the substrate 1101 is incorporated into the display panel 12 and then activated, the fluorescent surface of the display panel 12 is set to the anode electrode 111.
Used as 4. While applying the voltage 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 1
Control the operation of 112.

An example of the emission current Ie measured by the ammeter 1116 is shown in FIG.
When the pulse voltage is started to be applied from 2, the emission current Ie increases with the passage of time, but eventually becomes saturated and hardly increases. As described above, when the emission current Ie is almost saturated, the voltage application from the activation power supply 1112 is stopped, and the energization activation process is ended.

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

As described above, the plane type surface conduction electron-emitting device shown in FIG. 12 (e) was manufactured.

[Vertical Surface Conduction Type Emitting Element] Next, another typical structure of the surface conduction type emitting element in which the electron emitting portion or its periphery is formed of a fine particle film, that is, the vertical type surface conduction type The structure of the emitting element will be described.

FIG. 15 is a schematic sectional view for explaining the basic structure of the vertical type.

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

The vertical type is different from the above-described flat type in that one of the device electrodes (1202) is provided on the step forming member 1206, and the conductive thin film 1204 covers the side surface of the step forming member 1206. The point is that they are covered. Therefore, the device electrode spacing L in the flat type shown in FIG.
In the vertical type, it is set as the step height Ls of the step forming member 1206. The substrate 1201 and the device electrode 120
2 and 1203, a conductive thin film 120 using a fine particle film
For 4, it is possible to use the materials listed in the description of the planar type in the same manner. Also, the step forming member 1
For 206, an electrically insulating material such as SiO2 is used.

Next, a method for manufacturing the vertical type surface conduction electron-emitting device will be described. 16 (a) to 16 (f) are cross-sectional views for explaining the manufacturing process in the present embodiment, the notation of each member is the same as that in FIG. 15, and it is manufactured according to the following (1) to (7). .

(1) First, as shown in FIG.
A device electrode 1203 is formed on the substrate 1201.

(2) As shown in FIG. 13B, an insulating layer 1206 for forming a step forming member is laminated. The insulating layer 1206 may be formed by laminating SiO2 by a sputtering method, but other film forming methods such as a vacuum vapor deposition method and a printing method may be used.

(3) As shown in FIG. 7C, the insulating layer 1
A device electrode 1202 is formed on 206.

(4) As shown in FIG.
A part of 206 is removed by using, for example, an etching method,
The device electrode 1203 is exposed.

(5) As shown in FIG. 7E, a conductive thin film 1204 using a fine particle film is formed. To form the conductive thin film 1204, a film forming technique such as a coating method may be used as in the case of the flat type.

(6) As in the case of the flat type, the energization forming process is performed to form the electron emitting portion 1205.
(The same process as the planar energization forming process described with reference to FIG. 12C may be performed.) (7) The energization activation process is performed as in the case of the planar type.
Carbon or carbon compound 12 near the electron emission portion 1205
06 is deposited. (The same process as the planar energization activation process described with reference to FIG. 12D may be performed.) As described above, the vertical surface conduction electron-emitting device shown in FIG. Manufactured. [Characteristics of surface conduction electron-emitting device used in display device]
The device configuration and the manufacturing method of the planar type and the vertical type surface conduction electron-emitting device have been described. Next, the characteristics when the surface conduction electron emission device is used in a display device will be described.

FIG. 17 shows characteristics of (emission current Ie) vs. (element applied voltage Vf) of an element using the surface conduction electron-emitting device of this embodiment for a display device, and (element current If) vs. (element applied voltage). It is a figure which shows the typical example of Vf) characteristic.
Note that the emission current Ie is significantly smaller than the device current If and is difficult to be illustrated on the same scale, and these characteristics are changed by changing design parameters such as the size and shape of the device. Therefore, the two graphs are shown in arbitrary units.

The electron-emitting device used in the display device of this example has the following three characteristics regarding the emission current Ie.

First, a certain voltage (this is the threshold voltage Vth
The emission current Ie sharply increases when a voltage of the above magnitude is applied to the element, while the emission current Ie is hardly detected at a voltage lower than the threshold voltage Vth. That is, it is a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie.

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

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

Due to the above-mentioned characteristics, the surface conduction electron-emitting device could be preferably used in a display device. For example, in a display device in which a large number of elements are provided corresponding to the pixels of the display screen, by utilizing the first characteristic, it is possible to sequentially scan and display the display screen. That is, a voltage equal to or higher than the threshold voltage Vth is appropriately applied to the driven element according to the desired light emission luminance, and the threshold voltage Vth is applied to the non-selected element.
A voltage less than th is applied. By sequentially switching the elements to be driven in this manner, it is possible to sequentially scan the display screen for display.

Further, since the emission brightness can be controlled by utilizing the above-mentioned second characteristic or the third characteristic, it is possible to carry out gradation display.

[Structure of multi-electron beam source in which a large number of elements are wired 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 wired in a simple matrix will be described.

FIG. 18 is a plan view of the multi-electron beam source used for the display panel 12 of FIG. As described above, the surface conduction electron-emitting devices similar to those shown in FIG. 11 are arranged on the substrate 1001, and these devices are connected to the row-direction wirings 55 and the column-direction wirings 54 and wired in a simple matrix. Has been done. An insulating layer (not shown) is formed between the electrodes at the intersection of the row wiring 55 and the column wiring 54 to maintain electrical insulation.

FIG. 1 is a sectional view taken along the line AA 'in FIG.
9 shows.

The multi-electron source having such a structure is
The row-direction wiring 55 and the column-direction wiring 5 are previously formed on the substrate 1001.
4. After forming the inter-electrode insulating layer (not shown), the element electrode of the surface conduction electron-emitting device and the conductive thin film, each element is supplied with electricity through the row-direction wiring 55 and the column-direction wiring 54 to conduct electricity. It was manufactured by performing a forming treatment and an energization activation treatment.

FIG. 20 shows a display panel 12 using the surface conduction electron-emitting device of this embodiment as an electron beam source.
2 is a block diagram showing an example of a multi-function display device configured to be able to display image information provided from various image information sources such as television broadcasting.

In the figure, 12 is the above-mentioned display panel, 2101 is a drive circuit for the display panel 12,
2101a is a drive circuit for outputting a video signal, 2101b
Indicates a drive circuit that outputs a scanning signal. Incidentally, when the display device of the present embodiment receives a signal including both video information and audio information, such as a television signal, it naturally reproduces audio at the same time as displaying video. Reception of voice information not directly related to the features of the embodiment,
Descriptions of circuits, speakers, etc. relating to separation, reproduction, processing, storage, etc. are omitted.

The functions of the respective parts will be described below along the flow of image signals.

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 TV signal system to be received is not particularly limited, and may be a prescription system such as an NTSC system, a PAL system, or a SECAM system. Further, a TV signal (for example, a so-called high-definition TV such as the MUSE system) having a larger number of scanning lines than these is a signal suitable for taking advantage of the display panel 12 suitable for a large area and a large number of pixels. Is the 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 by using a wired transmission system such as a coaxial cable or an optical fiber. Similar to the TV signal receiving circuit 2113, the system of the TV signal to be received is not particularly limited, and the TV signal received by this circuit is also output to the decoder 2104. Also, the image input interface circuit 2111
Is a circuit for capturing an image signal supplied from an image input device such as a TV camera or an image reading scanner, and the captured image signal is output to the decoder 2104.

Image memory interface circuit 2110
Is a circuit for capturing an image signal stored in a video tape recorder (hereinafter abbreviated as VTR), and the captured image signal is output to the decoder 2104. The image memory interface circuit 2109 is a circuit for capturing the image signal stored in the video disc, and the captured image signal is output to the decoder 2104.
The image memory interface circuit 2108 is a circuit for capturing an image signal from a device that stores still image data, such as a so-called still image disc, and the captured still image data is output to the decoder 2104.

The input / output interface circuit 2105 is
It is a circuit for connecting the display device to an external computer, a computer network, or an output device such as a printer. It is of course possible to input and output image data, character data, and graphic information, and in some cases, input and output control signals and numerical data between the CPU 2106 of the display device and the outside. . The image generation circuit 2107 generates display image data based on image data or character / graphic information input from the outside via the input / output interface circuit 2105 or image data or character / graphic information output from the CPU 2106. It is a circuit for doing. Inside this circuit, for example, a rewritable memory for accumulating image data and character / graphic information, a read-only memory in which image patterns corresponding to character codes are stored, and a processor for performing image processing The circuits necessary for image generation are incorporated.

The display image data generated by the circuit of this embodiment is output to the decoder 2104, but in some cases, it is also possible to input / output to / from an external computer network or printer via the input / output interface circuit 2105. Is.

Further, the CPU 2106 mainly performs operations related to operation control of the display device and generation, selection and editing of a display image. For example, a control signal is output to the multiplexer 2103 to appropriately select or combine image signals to be displayed on the display panel. At that time, a control signal is generated to the display panel controller 2102 according to the image signal to be displayed, the screen display frequency, the scanning method (for example, interlace or non-interlace), the number of scanning lines in one screen, and the like. The operation of the display device is controlled as appropriate. Image data or character / graphic information is directly output to the image generation circuit 2107, or an external computer or memory is accessed via the input / output interface circuit 2105 to input image data or character / graphic information. .

It should be noted that the CPU 2106 may of course be involved in work for purposes other than this. 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, as described above, the computer may be connected to an external computer network via the input / output interface circuit 2105, and work such as numerical calculation may be performed in cooperation with an external device.

The input unit 2114 is the CPU 21
A user inputs commands, programs, data, etc. at 06. For example, various input devices such as a joystick, a bar code reader, and a voice recognition device can be used in addition to a keyboard and a mouse.

The decoder 2104 converts various image signals input from the above 2107 to 2113 into three primary color signals,
Alternatively, it is a circuit for inversely converting the luminance signal into the I signal and the Q signal. Note that it is desirable that the decoder 2104 includes an image memory therein, as indicated by a dotted line in the figure. This is to handle a television signal that requires an image memory for reverse conversion, such as the MUSE method. Also, by providing an image memory,
There is an advantage that a still image can be easily displayed, or image processing and editing such as pixel thinning, interpolation, enlargement, reduction, and synthesis can be easily performed in cooperation with the image generation circuit 2107 and the CPU 2106. Because.

The multiplexer 2103 is the CPU 2
A display image is appropriately selected based on a control signal input from 106. That is, the multiplexer 2103 selects a desired image signal from the inversely converted image signals input from the decoder 2104 and selects the drive circuit 2101.
a, 2101b. In that case, by switching and selecting image signals 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 television. . Also, the display panel controller 2102
Is a circuit for controlling the operation of the drive circuits 2101a and 2101b based on the control signal input from the CPU 2106.

First, as a component related to the basic operation of the display panel 12, for example, a signal for controlling an operation sequence of a power source (not shown) for driving the display panel is output to the drive circuits 2101a and 2101b. .

Further, regarding the driving method of the display panel, for example, a signal for controlling the screen display frequency and the scanning method (for example, interlace or non-interlace) is output to the drive circuits 2101a and 2101b.

In some cases, control signals relating to image quality adjustment such as brightness, contrast, color tone and sharpness of a display image may be output to the drive circuits 2101a and 2101b. The drive circuits 2101a and 2101 are
It is a circuit for generating a drive signal to be applied to the display panel 12, and operates based on an image signal input from the multiplexer 2103 and a control signal input from the display panel controller 2102.

The function of each unit has been described above. With the configuration illustrated in FIG. 20, the display panel 1 displays image information input from various image information sources in this display device.
2 can be displayed. That is, various image signals such as television broadcast are inversely converted by the decoder 2104, appropriately selected by the multiplexer 2103, and input to the drive circuits 2101a and 2101b.
On the other hand, the display controller 2102 generates a control signal for controlling the operation of the drive circuits 2101a and 2101b according to the image signal to be displayed. Drive circuit 21
01a and 2101b apply a drive signal to the display panel 12 based on an image signal and a control signal.

As a result, the image is displayed on the display panel 12. These series of operations are performed by the CPU
It is controlled by 2106 as a whole. Further, in the present display device, the image memory built in the decoder 2104, the image generation circuit 2107 and the CPU 2106 are involved, so that not only the one selected from the plurality of image information is displayed but also the selected one is displayed. For image information, for example, image processing such as enlargement, reduction, rotation, movement, edge enhancement, thinning, interpolation, color conversion, and aspect ratio conversion of images,
It is also possible to perform image editing such as composition, deletion, connection, replacement, and fitting. Although not particularly mentioned in the description of this embodiment, a dedicated circuit for processing and editing audio information may be provided as in the case of the above-mentioned image processing and image editing.

Therefore, the present display device is a display device for television broadcasting, a terminal device for a video conference, an image editing device for handling still images and moving images, a computer terminal device, an office terminal device such as a word processor, a game machine, etc. It is possible to combine the functions of a single unit, and it has an extremely wide range of applications for industrial or consumer use.

Note that FIG. 20 merely shows an example of the configuration of a display device using a display panel having a surface conduction electron-emitting device as an electron beam source, and it is needless to say that it is not limited to this. Yes. For example, of the components shown in FIG. 20, circuits relating to functions that are unnecessary for the purpose of use may be omitted. On the contrary, the constituent elements may be added depending on the purpose of use. For example, when the display device is applied as a videophone, it is preferable to add a television camera, a voice microphone, an illuminator, a transmission / reception circuit including a modem, and the like to the constituent elements.

In the present display device, in particular, since the display panel using the surface conduction electron-emitting device as the electron beam source can be easily thinned, the depth of the entire display device can be reduced. In addition, a display panel using a surface conduction electron-emitting device as an electron beam source can easily have a large screen, has high brightness, and has excellent viewing angle characteristics. Therefore, the display device of the present embodiment has a realistic and powerful image. Can be displayed with good visibility.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. The present invention can also be applied to the case where it is achieved by supplying a program for implementing the present invention to a system or an apparatus.

As described above, according to this embodiment, 2
Since the electrons emitted from the one electron emitting portion irradiate one phosphor to emit light, the emission brightness of the phosphor can be approximately doubled.

Further, according to the present embodiment, it is not necessary to increase the value of the current flowing through the wiring in the row direction or the wiring in the column, and it is not necessary to increase the acceleration voltage for accelerating the electrons in the face plate direction.

Further, according to the present embodiment, since the phosphors at two locations are irradiated with electrons by one electron emitting portion, the number of phosphors and the number of electron emitting portions may be substantially the same. Therefore, the resolution does not deteriorate.

Further, according to this embodiment, even if one of the two electron-emitting portions fails to emit electrons due to some reason, the other electron-emitting portion normally emits electrons. If it can be emitted, the phosphor that does not emit light will not be generated, and thus the occurrence of omission of the display pixel can be suppressed.

[0166]

As described above, according to the present invention, it is possible to increase the emission brightness without increasing the voltage applied to the electron source or the voltage for accelerating the electrons.

Further, according to the present invention, by making one phosphor emit light by the electrons from a plurality of electron sources, there is an effect that the emission brightness can be increased.

According to the present invention, even if a defect occurs in one electron source, it can be compensated by another electron source.

According to the present invention, by changing the voltage direction applied to the electron source between the first display scanning and the second display scanning, it is possible to easily perform the interlaced scanning for display. There is an effect.

[0170]

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a display drive circuit of a display device of this embodiment.

FIG. 2 is a diagram illustrating an arrangement of electron-emitting devices in the display panel of this embodiment.

FIG. 3 is a diagram showing trajectories of electrons emitted from an electron emitting portion of the electron emitting device of the present embodiment.

FIG. 4 is a timing chart when the display device is driven without performing interlaced scanning in the first embodiment of the present invention.

FIG. 5 is a diagram showing a state in which electrons are emitted from an electron emitting portion and are applied to a phosphor in the first embodiment when interlaced scanning is not performed.

FIG. 6 is a timing chart when the display device is driven by performing interlaced scanning in the second embodiment of the present invention.

FIG. 7 is a diagram showing a state in which electrons are emitted from an electron emitting portion and are applied to a phosphor in the second embodiment when interlaced scanning is not performed.

FIG. 8 is a diagram showing a state in which electrons are emitted from an electron emitting portion and are applied to a phosphor when the interlaced scanning is not performed in the second embodiment.

FIG. 9 is a partially exploded perspective view showing the configuration of the display panel of the image forming apparatus according to the exemplary embodiment of the present invention.

FIG. 10 is a schematic view of a fluorescent screen of a conventional image forming apparatus.

FIG. 11 is a plan view (a) and a cross-sectional view (b) of the planar surface conduction electron-emitting device used in this example.

FIG. 12 is a cross-sectional view showing the manufacturing process of the planar surface conduction electron-emitting device of the present embodiment.

FIG. 13 is a diagram showing an applied voltage waveform of an energization forming process in the present embodiment.

FIG. 14 is a diagram showing an applied voltage waveform (a) and a change in emission current Ie (b) during energization activation processing in the present embodiment.

FIG. 15 is a plan view of a vertical surface conduction electron-emitting device used in this example.

FIG. 16 is a cross-sectional view showing the manufacturing process of the vertical surface conduction electron-emitting device of the present embodiment.

FIG. 17 is a graph showing typical characteristics of the surface conduction electron-emitting device used in this example.

FIG. 18 is a diagram illustrating an array of multiple electron sources according to the present embodiment.

FIG. 19 is a cross-sectional view of the substrate of the multi-electron beam source shown by AA ′ in FIG.

FIG. 20 is a block diagram showing a configuration of an image forming apparatus according to an exemplary embodiment of the present invention.

FIG. 21 is a diagram showing an example of a conventional surface conduction electron-emitting device.

FIG. 22 is a diagram showing how electrons are emitted from a conventional surface conduction electron-emitting device.

FIG. 23 is an equivalent circuit diagram illustrating a wiring method of electron-emitting devices according to the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 signal processor 2 modulation signal generator 3 timing control circuit 4, 5 switching circuit 6 pulse generator 7 scanning row selection circuit 8, 10 switch 9 inverter 11 MOS-FET gate 12 display panel 13,1002 electron-emitting device 53 electron Emission part 54 Column direction wiring 55 Row direction wiring 56,57 Electrode 110,111,120 Phosphor 154,1005 Rear plate 155,1007 Face plate 1001 Substrate

Claims (13)

[Claims] 1. A multi-electron beam source in which a surface conduction electron-emitting device having a pair of electrodes and an electron-emitting portion is connected in a plurality of rows to form a matrix, and a multi-electron beam source is emitted from the electron beam source. In an image display device including a phosphor that emits electrons, a scanning row selection unit that selects any two rows from a plurality of rows of the surface conduction electron-emitting device included in the multi-electron beam source; and the scanning row. A scan driving unit for applying a driving signal to the two rows of the surface conduction electron-emitting devices selected by the selecting unit, and a voltage value of each driving signal applied to the pair of electrodes for inverting every predetermined period. An image display device comprising: a polarity reversing unit. 2. The image display device according to claim 1, wherein the drive signal includes a scanning signal in a row direction and a video signal in a column direction. 3. The image display device according to claim 2, wherein the inversion is to invert electrical polarities of the scanning signal and the video signal. 4. The multi-electron beam source includes row-direction wirings and column-direction wirings for wiring a plurality of surface conduction electron-emitting devices in a matrix, and the scanning row selection means is provided in the row-direction wirings. The image display device according to any one of claims 1 to 3, wherein the image display device is connected. 5. The method according to claim 4, further comprising means for inputting the video signal to the column-direction wiring, and means for inverting the voltage values of the scanning signal and the video signal at each predetermined period. The image display device according to. 6. The scan signal and the video signal have the same absolute value of voltage and opposite electrical polarities, and the inversion of the voltage value of these two signals is the inversion of the electrical polarity. The image display device according to claim 4. 7. The polarity inverting means inverts the polarity of the voltage value of each drive signal applied to the pair of electrodes for each horizontal scanning period of an image, according to any one of claims 1 to 6. The image display device according to item 1. 8. The polarity inversion means inverts the polarity of the voltage value of each drive signal applied to the pair of electrodes for each field period of an image.
The image display device according to any one of 1. 9. The row-direction wirings are paired in upper and lower pairs, the two wirings in the pair have a narrow wiring interval, and the two wirings in the upper and lower rows are spaced from each other. The image display device according to claim 4, wherein the image display device is provided. 10. An image display device for inputting and displaying an image signal, comprising: input means for inputting an image signal; and separating means for separating a video signal and a timing signal from the image signal input by the input means. A multi-electron beam source in which a plurality of surface conduction electron-emitting devices each having a pair of electrodes and an electron-emitting portion connected to the pair of electrodes are formed in a plurality of rows; Display means having a phosphor that emits light by emitted electrons, and a column drive for driving the surface conduction electron-emitting devices arranged in the column direction of the display means based on the video signal separated by the separating means. Means and a row drive for simultaneously driving two rows of the surface conduction electron-emitting devices arranged in the row direction of the display means based on the timing signal separated by the separating means. The image display apparatus characterized by comprising: a stage, and a switching means for inverting each other the electrical polarity of the timing signal output by the video signal output from said column drive means and the row drive means. 11. The image display device according to claim 10, wherein the row driving unit drives rows adjacent to each other. 12. The phosphors are driven to emit light based on electrons emitted from at least two surface electron-emitting devices that are simultaneously driven by the row driving means and the column driving means. Item 10. The image display device according to item 10 or 11. 13. The switching means reverses the electrical polarities of the video signal and the timing signal in the first and second scans of the interlaced scan. 2. The image display device according to item 1.