JPH0883584A - Flat panel display - Google Patents

Abstract

(57) [Abstract] [Purpose] Electrons emitted from the cathode are deflected by a deflection electrode in the direction of a control electrode corresponding to a display scanning line, and the electrons are collected at the control electrode, whereby a flat type with a high electron utilization rate is obtained. Get the display. A light emitting body, a back electrode provided at a position facing the light emitting body, a cathode provided between the back electrode and the light emitting body, a cathode and the light emitting body A surface insulating substrate having a plurality of electron passage holes interposed therebetween, and a control electrode to which a passing electron control voltage is applied, which is separately provided on both surfaces of the surface insulating substrate. A perforated cover electrode that covers the control electrode side of the cathode and has a large number of holes through which electrons pass,
In a flat panel display device having a deflection electrode provided between the perforated cover electrode and the control electrode for deflecting electrons, the electrons emitted from the cathode are deflected by the deflection electrode in the direction of the control electrode corresponding to the display scanning line. Then, the control electrodes were made to collect electrons.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel display device using an electron beam.

[0002]

2. Description of the Related Art FIGS. 7 and 8 show, for example, JP-A-3-22.
6 is a cross-sectional perspective view and a cross-sectional front view showing a part of a conventional flat-panel display device disclosed in Japanese Patent Publication No. 6949 and Japanese Patent Laid-Open No. 3-245445, in which 1 is connected to a support and energized. A linear hot cathode that emits electrons by
Reference numeral 2 is a perforated cover electrode having an elliptical cross section that covers the upper surface of the linear hot cathode 1. The perforated cover electrode 2 has a large number of small holes for passing electrons, and the electrons are extracted from the linear hot cathode 1 by applying an appropriate potential. The linear hot cathode 1, the perforated cover electrode 2, and the perforated cover electrodes 2 arranged in parallel are fixed, and the electron radiation source 10 is formed by the perforated cover electrode 2 and the back electrode 11 having substantially the same potential. I am configuring. 3 is a phosphor of three types that emits red, green, and blue light when excited by the electrons emitted from the electron emission source 10.
Is a front glass forming a sealed container 12 having a dot-shaped coating on the inner surface side, and an aluminum film (not shown) formed on the inner surface for conductivity. By applying a voltage of about 30 kV, the electrons are accelerated and the phosphor 4 is excited to emit light. Reference numeral 5 is interposed between the front glass 3 and the linear hot cathode 1, and is drawn out by the perforated cover electrode 2.
A surface insulating substrate, for example, a glass insulating substrate 7, which is a control electrode portion for passing or blocking electrons going toward it, and having electron passing holes 6 corresponding to the pixels on the front glass 3.
A line-sequential drive electrode group 8 composed of strip-shaped metal electrodes 8a arranged on the surface of the insulating substrate 7 on the side of the electron emission source 10 corresponding to every 1 row of pixels, and the phosphor 4 of the insulating substrate 7 in the same manner. The gradation control electrode group 9 is composed of strip-shaped metal electrodes 9a arranged on the side surface corresponding to each one column of pixels. The metal electrodes 8a, 9a of the line-sequential drive electrode group 8 and the gradation control electrode group 9 are made of, for example, a nickel film and enter the electron passage holes 6, respectively, but no nickel film is attached to the holes. There is a portion, and the line-sequential drive electrode group 8 and the gradation control electrode group 9 are insulated. In addition, in the line-sequential drive electrode group 8, insulating grooves without a nickel film, that is, separation bands 13, are provided between the electron passage holes 6 in a direction orthogonal to the linear hot cathode 1. Similarly, the gradation control electrode group 9 includes the separation band 13 of the line-sequential drive electrode group 8.
Separation bands 14 are provided in a direction orthogonal to, that is, in a direction parallel to the linear hot cathode 1. These are installed in the sealed container 12 and the inside is kept in vacuum. Each electrode is electrically connected to the outside from a sealing portion provided on the side surface. In this example, a hole made of stainless steel with a high aperture ratio,
For example, a grid electrode 15 in which square holes each having a side of 1.8 mm are formed at a pitch of 2 mm is provided between the perforated cover electrode 2 and the control electrode portion 5.

FIG. 10 is a diagram showing a display example of the screen, FIG. 9 is a diagram showing a waveform of a voltage applied to the control electrode 5 in the display example of FIG. 10, and FIG. 11 is a peripheral circuit of a conventional flat display device. It is a block diagram showing. In the figure, 16 is a signal processing circuit that performs gamma correction of a video signal, 17 is a pulse width modulation circuit that changes the pulse width according to the size of the video signal, and 1
Reference numeral 8 is a gradation control electrode drive circuit for setting the output of the pulse width modulation circuit 17 to a predetermined voltage and inputting it to the gradation control electrode 9, and 19 is a line for inputting a predetermined voltage to the line-sequential drive electrode 8. It is a drive circuit for a sequential drive electrode.

Next, the operation will be described. Linear hot cathode 1
The thermoelectrons emitted from the cathode are about 5 to 4 based on the average potential of the linear hot cathode 1 (hereinafter, this average potential is 0 V).
It is uniformly radiated in the direction of the phosphor 4 by the perforated cover electrode 2 and the back electrode 11 to which 0 V is applied.
The grid electrode 15 to which 150 V is applied is sent out to just before the control electrode portion 5, and further to one of the line-sequential drive electrode group 8 composed of the metal electrodes 8a arranged in the direction orthogonal to the linear hot cathode 1. By applying a positive potential of about 20 to 100 V, thermoelectrons are attracted to this electrode and reach the control electrode section 5. Elliptical columnar shape of the perforated cover electrode 2,
By adjusting the position of the line-sequential drive electrode group 8 and the voltage applied to each metal electrode 8a, the electron current density on the front surface of any one metal electrode 8a of the line-sequential drive electrode group 8 is substantially uniform. Is made to be.

The operation of the control electrode section 5 is as follows. As described above, if only one metal electrode 8a of the line-sequential drive electrode group 8 has a positive potential (on state) and the other has 0 V or a negative potential (off state),
The thermoelectrons emitted from the linear hot cathode 1 are attracted only to the l ON-state metal electrodes 8a, and the metal electrodes 8
It goes into the electron passage hole 6 in the l-th row where a is provided.
All the electrons that have entered the electron passage hole 6 do not pass to the front glass 3 side as they are, but the electron passage hole 6
In the gradation control electrode group 9 provided on the front glass 3 side, electrons pass only through the electron passage holes 6 corresponding to the metal electrodes 9a in the ON state to which a potential of 40 to 100 V is applied, and the other 0 V is applied. Alternatively, it does not pass through the electron passage hole 6 corresponding to the off-state metal electrode 9a having the negative potential.
Therefore, electrons pass only through the electron passage holes 6 at the intersections of the one metal electrode 8a in the ON state of the line-sequential drive electrode group 8 and the metal electrode 9a in the ON state of the gradation control electrode group 9.
Then, the passing electrons cause the phosphor 4 at the pixel position corresponding to the electron passing hole 6 to emit light, and display is performed. That is, a desired image can be displayed by controlling the voltage application to the metal electrodes 8a and 9a so that the intersections correspond to the desired positions. For example, the metal electrodes 8a of the line-sequential drive electrode group 8 are sequentially turned on one by one, and the metal electrodes 9a in the grayscale control electrode group 9 corresponding to the position to emit light in synchronization therewith are turned on. An image is displayed by repeating this (scanning) 60 screens per second such that it is not felt by human eyes.

In the case of an interlaced signal, every other line-sequential drive electrode 8 is sequentially turned on, and the brightness information of the corresponding line is simultaneously given to all the gradation control electrodes 9. Thus, in the case of the display example as shown in FIG. 10, it suffices to apply a voltage to the control electrode 5 as shown by the waveform in FIG.

Although each control electrode has entered the electron passage hole, it is possible to block the passage of electrons by applying a small negative potential of 0V to several 10V to each control electrode when it is turned off. The electric field is effectively applied to the electrons that have entered the electron passage hole.

The brightness of each pixel is determined by the gradation control electrode group 9
The time is controlled by turning on each metal electrode 9a. That is, assuming that the on-state time of the line-sequential drive electrode group 8 is ty, the on-state time tx of the metal electrode 9a of the gradation control electrode group 9 corresponding to the position when the pixel at the predetermined position is set to the brightness of P% is P · ty / 100 is recommended.

[0009]

Since the conventional flat-panel display device is constructed as described above, it is possible that a certain one of the shower-shaped electron sources contributes to the display at a certain moment.
There is a problem that the utilization rate of electrons is low because it is only for lines.

The present invention has been made in order to solve the above problems, in which electrons emitted from a cathode are deflected by a deflection electrode in the direction of a control electrode corresponding to a display scanning line, and the electrons are emitted to the control electrode. Try to collect. Alternatively, another object of the present invention is to obtain a flat-panel display device having a high utilization rate of electrons by focusing the collected electrons with a focusing electrode and ensuring that the collected electrons can pass through the control electrode.

[0011]

A flat-panel display device according to claim 1 of the present invention comprises a light-emitting body and a back electrode provided at a position facing the light-emitting body in a hermetically sealed container kept in vacuum. A cathode provided between the back electrode and the light emitter for emitting electrons to the light emitter; a surface insulating substrate having a plurality of electron passage holes interposed between the cathode and the light emitter; A plurality of control electrodes, which are separately provided on both sides of the insulating substrate, to which a passing electron control voltage is applied, and a large number of holes which cover at least the control electrode side of the cathode and allow electrons to pass through are provided. In a flat-panel display device having a hole cover electrode and a deflection electrode provided between the perforated cover electrode and a control electrode for deflecting electrons, the electron emitted from the cathode is displayed and scanned by the deflection electrode. In the direction of the control electrode corresponding to the line And direction is obtained by the collect electrons to the control electrode.

According to a second aspect of the present invention, in the flat panel display device, a light emitting body, a back electrode provided at a position facing the light emitting body, and a back electrode are provided in a sealed container kept in a vacuum. A cathode for emitting electrons to the light emitter, a surface insulating substrate having a plurality of electron passage holes interposed between the cathode and the light emitter, and a surface insulating substrate of the surface insulating substrate. A control electrode provided on each of the two surfaces separately, to which a passing electron control voltage is applied, and a perforated cover electrode that covers at least the control electrode side of the cathode and has a large number of holes through which electrons pass. A deflection electrode provided between the perforated cover electrode and the control electrode for deflecting electrons, and a focusing electrode provided between the deflection electrode and the control electrode for focusing the electrons. In a flat-panel display device including Electrons emitted from the cathode are deflected by the deflection electrode in the direction of the control electrode corresponding to the display scanning line, the electrons are collected on the control electrode, the collected electrons are focused by the focusing electrode, and the collected electrons are reliably controlled. It is designed to pass through the electrodes.

[0013]

In the flat-panel display device according to the first aspect of the present invention, the electrons emitted from the cathode are deflected by the deflection electrode toward the control electrode corresponding to the display scanning line, and the electrons are collected on the control electrode. , The number of electrons reaching the control electrode increases.

Further, in the flat-panel display device according to the second aspect of the present invention, the electrons emitted from the cathode are deflected by the deflection electrode toward the control electrode corresponding to the display scanning line, and the electrons are collected on the control electrode. By focusing the collected electrons with the focusing electrode, the collected electrons can surely pass through the control electrode, and more electrons are sent to the light emitter.

[0015]

【Example】

Example 1. Hereinafter, a flat panel display according to an exemplary embodiment of the present invention will be described with reference to the drawings. 1, 3, and 5 are a cross-sectional perspective view, a cross-sectional front view, and a cross-sectional side view showing a part of a flat-panel display device. In the figure, reference numeral 20 denotes a deflection electrode for deflecting electrons emitted from the cathode in the direction of the control electrode corresponding to the display scanning line, which is arranged in a direction orthogonal to the linear hot cathode 1.

Next, the operation will be described. Linear hot cathode 1
The thermoelectrons emitted from are uniformly radiated toward the phosphor 4 by the perforated cover electrode 2 and the back electrode 11. A voltage is applied to 1 of the line-sequential drive electrode group 8 composed of the metal electrodes 8a arranged in the direction orthogonal to the linear hot cathode 1. Electrons are deflected by the deflection electrode so that the electrons gather on the metal electrode 8a to which this voltage is applied. Next, the grid electrode 1
By applying a voltage to 1 of the line-sequential drive electrode group 8 composed of the metal electrode 8a, which is sent to the position immediately before the control electrode unit 5 at 5 and is arranged in the direction orthogonal to the linear hot cathode 1. The thermoelectrons are attracted to this electrode and reach the control electrode unit 5. By adjusting the elliptic cylinder shape of the perforated cover electrode 2, the position of the line-sequential drive electrode group 8 and the voltage applied to each metal electrode 8a, any one metal electrode of the line-sequential drive electrode group 8 is adjusted. The electron current density on the front surface of 8a is substantially uniform.

A method of deflecting electrons will be described in detail with reference to FIG. Here, the line shown by the thick line is the orbit of the electron. When the n-th metal electrode 8a is in the ON state, the electrons are deflected so that the electrons gather there. Deflection electrode 20
Electrons that pass between the n-th and (n + 1) -th points of the voltage are applied to the n-th and the n + 1-th of the deflection electrode 20 so as to reach the metal electrode 8an straight without being deflected. The applied voltage value is set to a value that does not affect the potential gradient between the grid electrode 15 and the perforated cover electrode 2. A voltage having a lower value than the (n-1) th and (n + 2) th deflection electrodes 20 is applied. Then, n, (n +
The orbit of the electron is bent because a potential gradient is created between the 1) th and the (n-1) th and (n + 2) th. Similarly, (n-2) and (n + 3) th are (n-1) and (n +).
2) Apply a voltage lower than the second value. Then, (n
The orbit of the electron is bent because a potential gradient is formed between (-1), (n + 2) th and (n-2), (n + 3) th. If the voltage difference is set larger than before, the orbits of electrons are bent more. This is repeated for the deflecting electrodes 20 which are apart from each other. As a result, electrons come to collect on the metal electrode 8an.

Although the deflection electrode 20 is provided for each metal electrode 8a here, the same effect can be obtained by increasing the distance between the deflection electrodes 20.

By deflecting the electrons, the number of electrons reaching the metal electrode 8a in the ON state is increased as compared with the case where the electrons are not deflected. Therefore, the number of electrons passing through the control electrode portion 5 increases, and the number of electrons hitting the phosphor 4 also increases. As a result, the brightness is improved.

In addition, if the current amount of the linear hot cathode 1 is reduced so that the number of electrons passing through the control electrode portion 5 becomes the same as when the deflection is not performed, the brightness is the same as when the deflection is not performed. Since the current amount of the linear hot cathode 1 is small, the power consumption becomes low. The operation of the control electrode unit 5 is as usual.

Example 2. Hereinafter, a flat panel display device according to another embodiment of the present invention will be described with reference to the drawings. 2, 4 and 6 are a sectional perspective view, a sectional front view and a sectional side view showing a part of the flat panel display device. In the figure, reference numeral 20 denotes a deflection electrode for deflecting electrons emitted from the cathode in the direction of the control electrode corresponding to the display scanning line, which is arranged in a direction orthogonal to the linear hot cathode 1. Reference numeral 21 is a focusing electrode for focusing electrons.

Next, the operation will be described. Linear hot cathode 1
The thermoelectrons emitted from are uniformly radiated toward the phosphor 4 by the perforated cover electrode 2 and the back electrode 11. A voltage is applied to 1 of the line-sequential drive electrode group 8 composed of the metal electrodes 8a arranged in the direction orthogonal to the linear hot cathode 1. Electrons are deflected by the deflection electrode so that the electrons gather on the metal electrode 8a to which this voltage is applied. Next, the grid electrode 1
By applying a voltage to 1 of the line-sequential drive electrode group 8 composed of the metal electrode 8a, which is sent to the position immediately before the control electrode unit 5 at 5 and is arranged in the direction orthogonal to the linear hot cathode 1. The thermoelectrons are attracted to this electrode and reach the control electrode unit 5. However, the grid electrode 15 and the control electrode portion 5
A focusing electrode 21 is provided between the two to ensure that the control electrode can pass through. Further, by adjusting the elliptic cylinder shape of the perforated cover electrode 2, the position of the line-sequential drive electrode group 8 and the voltage applied to each metal electrode 8a, any one of the line-sequential drive electrode group 8 is adjusted. The electron current density on the front surface of the metal electrode 8a is made substantially uniform.

A method of deflecting electrons will be described in detail with reference to FIG. Here, the line shown by the thick line is the orbit of the electron. When the n-th metal electrode 8a is in the ON state, the electrons are deflected so that the electrons gather there. Deflection electrode 20
Electrons that pass between the n-th and (n + 1) -th points of the voltage are applied to the n-th and (n + 1) -th voltages of the deflection electrode 20 so as to reach the metal electrode 8an straight without being deflected. The applied voltage value is the grid electrode 15 and the perforated cover electrode 2
Set to a value that does not affect the potential gradient between and. The (n-1) th and (n + 2) th of the deflection electrode 20 are n and (n +).
1) Apply a voltage lower than the 1st. Then n,
Since the potential gradient is formed between the (n + 1) th position and the (n-1) th and (n + 2) th position, the orbit of the electron is bent. Similarly, (n-2), (n + 3) th is (n-1),
A voltage lower than the (n + 2) th voltage is applied. Then, (n-1), (n + 2) th and (n-2), (n +)
The orbit of the electron is bent due to the potential gradient between the 3) th and. If the voltage difference is set larger than before, the orbits of electrons are bent more. Deflection electrode 2 apart from this
Repeat with 0. As a result, electrons come to collect on the metal electrode 8an.

Although the deflection electrode 20 is provided for each metal electrode 8a here, the same effect can be obtained by increasing the distance between the deflection electrodes 20.

By deflecting the electrons, the number of electrons reaching the metal electrode 8a in the ON state is increased as compared with the case where the electrons are not deflected. Therefore, the number of electrons passing through the control electrode portion 5 increases, and the number of electrons hitting the phosphor 4 also increases. As a result, the brightness increases. Further, since the focusing electrode 21 is provided, the number of electrons which cannot collide with the control electrode 5 by colliding with the wall of the electron passage hole 6 of the control electrode portion 5 is reduced. Therefore, the number of electrons passing through the control electrode unit 5 is increased and the brightness is higher than that of the flat panel display device of the first embodiment.

In addition, if the current amount of the linear hot cathode 1 is lowered so that the number of electrons passing through the control electrode portion 5 becomes the same as when the deflection is not performed, the brightness is the same as when the deflection is not performed. Since the current amount of the linear hot cathode 1 is small, the power consumption becomes low. Further, since the focusing electrode 21 is provided, the number of electrons that collide with the control electrode unit 5 and cannot pass through is reduced. Therefore, the current amount of the linear hot cathode 1 can be reduced as compared with the flat-panel display device of Example 1, and the power consumption becomes lower. The operation of the control electrode unit 5 is as usual.

[0027]

As described above, according to the flat panel display device of the first aspect of the present invention, the electrons emitted from the cathode are deflected by the deflection electrode toward the control electrode corresponding to the display scanning line, Since the number of electrons coming to the control electrode is increased by collecting the electrons at the control electrode, the utilization rate of electrons emitted from the cathode is high.

Further, the number of electrons passing through the control electrode increases,
Since the number of electrons striking the light emitter increases, the brightness improves.

Furthermore, the current amount of the cathode can be reduced without lowering the brightness, and the power consumption can be reduced.

According to the flat-type display device of the second aspect of the present invention, the electrons emitted from the cathode are deflected by the deflection electrodes toward the control electrodes corresponding to the display scanning lines, and the electrons are emitted to the control electrodes. By collecting the collected electrons and focusing them with a focusing electrode, the collected electrons can surely pass through the control electrode and send more electrons to the control electrode. The rate is high.

Further, the number of electrons passing through the control electrode increases,
Since the number of electrons striking the light emitter increases, the brightness improves.

Furthermore, the current amount of the cathode can be reduced without lowering the brightness, and the power consumption can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional perspective view showing a part of a flat panel display according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional perspective view showing a part of a flat panel display according to another embodiment of the present invention.

FIG. 3 is a sectional front view showing a part of a flat panel display according to an exemplary embodiment of the present invention.

FIG. 4 is a sectional front view showing a part of a flat-panel display according to another embodiment of the present invention.

FIG. 5 is a sectional side view showing a part of a flat panel display according to an exemplary embodiment of the present invention.

FIG. 6 is a sectional side view showing a part of a flat panel display according to another embodiment of the present invention.

FIG. 7 is a cross-sectional perspective view showing a part of a conventional flat-panel display device.

FIG. 8 is a sectional front view showing a part of a conventional flat-panel display device.

FIG. 9 is an input voltage waveform diagram of a conventional control electrode.

FIG. 10 is a diagram showing a display example of a screen.

FIG. 11 is a block diagram showing a peripheral circuit of a conventional flat-panel display device.

[Explanation of symbols]

1 linear hot cathode, 2 perforated cover electrode, 3 front glass, 4 phosphor, 5 control electrode part, 6 electron passage hole, 7
Insulating substrate, 8 line sequential drive electrode, 8a, 9a metal electrode, 9 gradation control electrode, 10 electron emission source, 11 back electrode, 12 sealed container, 13, 14 separator, 15 grid, 16 signal processing circuit, 17 pulse Width modulation circuit, 18 gradation control electrode drive circuit, 19 line sequential drive electrode drive circuit, 20 deflection electrode, 21 focusing electrode.

Claims (2)

[Claims] 1. A light-emitting body in a sealed container kept in a vacuum,
A back electrode provided at a position facing the light emitting body, a cathode provided between the back electrode and the light emitting body for emitting electrons to the light emitting body, and a plurality of cathodes interposed between the cathode and the light emitting body. A surface insulating substrate having electron passing holes, a control electrode provided on each side of the surface insulating substrate separately from each other, to which a passing electron control voltage is applied, and at least a control electrode side of the cathode. And a flat display including a perforated cover electrode having a large number of holes through which electrons pass and a deflection electrode provided between the perforated cover electrode and the control electrode for deflecting electrons. In the device, a flat display device is characterized in that electrons emitted from a cathode are deflected by a deflection electrode toward a control electrode corresponding to a display scanning line, and the electrons are collected at the control electrode. 2. A luminous body in a hermetically sealed container kept under vacuum,
A back electrode provided at a position facing the light emitting body, a cathode provided between the back electrode and the light emitting body for emitting electrons to the light emitting body, and a plurality of cathodes interposed between the cathode and the light emitting body. A surface insulating substrate having electron passing holes, a control electrode provided on each side of the surface insulating substrate separately from each other, to which a passing electron control voltage is applied, and at least a control electrode side of the cathode. And a perforated cover electrode having a large number of holes through which electrons pass, a deflection electrode provided between the perforated cover electrode and the control electrode for deflecting electrons, a deflection electrode and a control electrode. Between the
In a flat-panel display device including a focusing electrode provided for focusing electrons, electrons emitted from a cathode are deflected by a deflection electrode toward a control electrode corresponding to a display scanning line, and the electrons are directed to the control electrode. A flat panel display device characterized in that the collected electrons are collected by a focusing electrode so that the collected electrons can surely pass through the control electrode.