JPH07272650A - Image display device - Google Patents

Abstract

PURPOSE:To prevent a vibration, reduce a coordination gradient at the time of heating and provide uniform brightness for improving image quality by forming an electron beam generation means out of a plurality of linear or coil type short hot-cathode wires laid like a ladder. CONSTITUTION:Electron beam generation means 2 formed out of a plurality of linear or coil type short hot-cathode wires 7 laid like a ladder so as to correspond to a plurality of electron beam control means 3, are provided in parallel to the stripes of a phosphor screen 4. Furthermore, every electron beam generation means 2 is provided with an electrically isolated rear electrode 12. This rear electrode 12 is provided with a means for applying pulse voltage thereto, a means for making voltage variable for application to the rear electrode 12, according to a brightness signal during the application, or a means for making a time variable for applying the voltage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel image display device for video equipment.

[0002]

2. Description of the Related Art In recent years, flattening and thinning of image display devices have been promoted, and further thinning of thin flat plate image display devices has been required.

A conventional flat panel image display device will be described below. Conventional flat panel image display devices are disclosed in, for example, Japanese Patent Application Laid-Open Nos. 51-113542 and 51-15.
1125, JP-A-53-51808, JP-A-57-208046, and JP-A-58-12972.
No. 7 publication is proposed. FIG. 5 shows an outline of a conventional flat panel image display device. In FIG. 5, 21
Is a back electrode, 22 is an electron beam generating means, and is composed of a plurality of hot cathode lines. Phosphor screen, 23
˜28 are electron beam control means, and in this example, the vertical focusing electrode 23, the vertical deflection electrode 24, the vertical focusing electrode 23 ′,
It is composed of an electron beam flow control electrode 25, a horizontal focusing electrode 26, a horizontal deflection electrode 27, and an electron beam accelerating electrode 28. 29 is a screen. 20 is a phosphor.

The operation of the image display device constructed as described above will be described below. First, the back electrode 21 creates a potential gradient with the vertical focusing electrode 23, and suppresses the generation of electron beams from the hot cathode rays other than the hot cathode rays 22 controlled to emit the electron beam for a certain period of time. At the same time, it acts to push the generated electron beam only forward. The electron beam generating means 22 is generally constituted by coating a fine wire of tungsten or the like with a carbonate of barium or the like, which is generally called a hot cathode, and applies a voltage to both ends to heat it from 650 ° C. to 750 ° C.
A pulsed voltage is applied for a certain period of time in order from the upper hot cathode line 22a, and the back electrode 21 and the vertical focusing electrode 23 described above are applied.
The electron beam is extracted by the potential gradient between and. The electron beam passing through the vertical focusing electrode 23 is vertically deflected by the electric field of the vertical deflection electrode 24.

Next, a plurality of electron beam flow control electrodes 25 are provided side by side in the horizontal direction, and each of the electron beam flow control electrodes 25 is divided into one horizontal pixel in the horizontal direction and taken out, and the amount of passage therethrough. Are controlled according to a video signal for displaying each picture element.

The electron beam accelerating electrode 28 is the vertical deflection electrode 2
It is composed of a plurality of conductive plates horizontally provided at the same position as 2, and has the function of vertical deflection expansion simultaneously with the acceleration of the electron beam. The screen 29 is configured by applying the phosphor 20 that is emitted by the irradiation of the electron beam to the back surface of the glass plate. The phosphor 20 is provided for one slit hole of the electron beam flow control electrode 25, that is, R, G, B for each one of the horizontally divided beams.
The phosphors of three colors are provided one by one, and are applied in stripes in the vertical direction.

[0007]

However, in the above-mentioned conventional configuration, when the size is increased, the electron beam generating means 2 is used.
Since 2 is a thin line, it has a problem that it vibrates due to an electric signal, voice output, external vibration, etc., and the image is blurred. Further, since the electron beam generating means 22 has a potential gradient when energized and therefore the brightness is not uniform, for example, in JP-A-53-51808, a pulse voltage is applied to the electron beam when extracting the electron beam by using a diode. It has been configured such that it is applied to the generating means 2 to avoid a temperature gradient due to energization.

Further, the electron beam generating means has a problem that there is a potential gradient even when the electron beam is taken out, and therefore the brightness is not uniform. Therefore, for example, a diode is used in JP-A-53-129727. However, there is a problem that the number of parts increases and the circuit becomes complicated. Furthermore, when aiming at higher definition, the hole of the electron beam extraction electrode in the electron beam control means must be made smaller in order to make the electron beam focus in the horizontal direction smaller, resulting in lower brightness. Had a problem.

In order to solve the above problems, the electron beam generating means are arranged in a ladder shape between the facing conductors in parallel with the stripes of the phosphor screen in correspondence with the plurality of electron beam control means. When a plurality of linear or coiled hot cathode wires are used, the hot cathode wires are short and the voltage for heating becomes a low voltage of 0.1V to 0.5V, so that the temperature of all hot cathode wires is made uniform. It was difficult to do.

Furthermore, if a pulsed voltage is applied to the electron beam generating means at the time of extracting an electron beam to avoid a temperature gradient due to energization as described above, a large number of electron beam generating means are electrically connected to each other. In addition, there is a problem that the number of terminals must be twice as large as that of the electron beam generating means, because of the problem that it must be insulated.

Further, conventionally, the brightness modulation has been performed by the pulse width modulation method by the electron beam flow control electrode 5 in the electron beam control means, but when it is driven at a high speed like a high definition tube, the pulse is modulated. Due to the blunt rising waveform of
There was a problem of image deterioration such as uneven color of electron beam focus at low brightness.

An object of the present invention is to solve the above-mentioned conventional problems, and an object thereof is to provide an image display device of high image quality which is free from image deterioration due to vibration of the electron beam generating means.

Another object of the present invention is to provide an image display device having uniform brightness.

[0014]

To achieve this object, in an image display device of the present invention, the electron beam generating means is arranged between the opposed conductors in parallel with the stripes of the phosphor screen. It is composed of a plurality of linear or coiled hot cathode wires arranged in a ladder shape corresponding to the beam control means.

Further, in order to achieve the second object, in the image display device of the present invention, at least one or more of the facing electric conductors of the electron beam generating means are electrically separated.
A ladder-shaped electron beam generating means is electrically connected in series.

Further, in order to achieve the third object, in the image display device of the present invention, at least one electron beam control means facing the electron beam generation means is electrically connected to each of the ladder-shaped electron beam generation means. It is composed of separate electrodes.

Further, in the image display device of the present invention, means for applying a pulsed voltage to the electrodes electrically separated by each of the ladder-shaped electron beam generating means and a back electrode according to a luminance signal during the period. And means for varying the applied voltage.

[0018]

According to the first structure of the present invention, the electron beam generating means is composed of a plurality of short hot cathode wires which are arranged in a ladder shape or a coil shape, thereby preventing vibration and heating. It is possible to provide a high-quality image display device having a uniform luminance and a small potential gradient.

Further, by arranging the hot cathode lines in parallel with the stripes of the phosphor screen, the horizontal electron beam focus can be reduced by directly extracting the horizontal image of the hot cathode lines.

Further, according to the second configuration, the present invention provides
In addition to the effect obtained by the first configuration, at least one or more of the facing conductors of the electron beam generating means are electrically separated, and the ladder-shaped electron beam generating means is electrically connected in series to electrically An appropriate voltage for heating the hot cathode lines can be obtained by arbitrarily setting the places to be cut off, the temperature of all the hot cathode lines can be made uniform, and a high-quality image display device with uniform brightness can be provided.

Further, according to the present invention, at least one of the electron beam control means facing the electron beam generation means is constituted by electrodes which are electrically separated for each ladder-shaped electron beam generation means. The generating means can take out the electron beam by the other separated electrodes while always applying the voltage for heating, the number of terminals for the electron beam generating means can be reduced, and the image display device is easy to make and has high reliability. Can be provided.

Further, according to the present invention, a means for applying a pulsed voltage to the electrodes electrically separated by each of the ladder-shaped electron beam generating means and a voltage applied to the back electrode in accordance with the luminance signal during the period. By providing the variable means, it is possible to provide an image display device of uniform high image quality even at low brightness.

[0023]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a back electrode, 2 is an electron beam generating means, and is composed of a plurality of hot cathode lines 7. Reference numeral 3 denotes an electron beam control means, which is composed of a focusing electrode 3a and other electrodes 3b, 3c ... In this example. 4 is a phosphor screen. Reference numeral 5 is a spacer made of an insulating material. Reference numeral 6 is a conductor for connecting the hot cathode line. Reference numerals 9a and 9b are connection terminals from the electron beam generating means 2. Reference numeral 10 is a connection terminal from the back electrode.

The electron beam control means 3 includes a plurality of plane electrodes 3a, 3b, 3c ... Insulating spacers (not shown).
It is configured to be laminated via. The electron beam generating means 2 is composed of a plurality of short hot cathode wires 7 arranged in a ladder shape or in a coil shape. The hot cathode wire 7 is usually formed by coating a fine wire of tungsten or a tungsten alloy with a carbonate such as barium.
The spacer 5 can be formed by printing a glass-based adhesive and firing it, or by spraying a ceramic.

The phosphor screen 4 comprises red, green and blue stripes 41a, 41b and 41c arranged in parallel with the hot cathode lines.

The operation of the image display device configured as described above will be described. First, the hot cathode wire 7 is previously
It is fixed by applying tension to prevent it from loosening due to elongation during heating. Therefore, the length of the hot cathode wire is short, and the vibration is suppressed to a negligible level. In addition, as described above, the length of the hot cathode wire 7 is short, so that the potential gradient during heating is reduced. Therefore, uneven brightness does not occur due to non-uniform potential. Furthermore, by arranging the hot cathode lines 7 in parallel with the stripes of the phosphor screen, the horizontal electron beam focus can be reduced by directly extracting the horizontal image of the hot cathode lines 7. The effect is obtained.

(Embodiment 2) A second embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, 1 is a back electrode, 2 is an electron beam generating means, and is composed of a plurality of hot cathode lines 7. Reference numeral 3 denotes an electron beam control means, which is composed of a focusing electrode 3a and other electrodes 3b, 3c ... In this example. 4 is a phosphor screen. Reference numeral 5 is a spacer made of an insulating material. Reference numeral 6 is a conductor for connecting the hot cathode line. Reference numerals 9a and 9b are connection terminals from the electron beam generating means 2. Reference numeral 10 is a connection terminal from the back electrode.

The electron beam control means 3 has a plurality of plane electrodes 3a, 3b, 3c ... Insulating spacers (not shown).
It is configured to be laminated via. The electron beam generating means 2 is composed of a plurality of short hot cathode wires 7 arranged in a ladder shape or in a coil shape. The hot cathode wire 7 is usually formed by coating a fine wire of tungsten or a tungsten alloy with a carbonate such as barium.
The spacer 5 can be formed by printing a glass-based adhesive and firing it, or by spraying a ceramic.

The phosphor screen 4 is composed of red, green and blue stripes 41a, 41b and 41c arranged in parallel with the hot cathode lines.

The above is the same as the configuration of FIG. The difference from the configuration in FIG. 1 is that at least one or more of the facing conductors 6 of the electron beam generating means 2 are electrically separated, and the ladder-shaped electron beam generating means 2 is electrically connected in series. .

The operation of the image display device configured as described above will be described. First, assuming that the voltage applied for heating with the above configuration is V, the number of cut-off points is n, and the applied voltage in the case of Example 1 is V1, V = n × V1 Become. In this way, an appropriate voltage for heating the hot cathode line can be obtained by arbitrarily setting the electrically disconnected portion.

As described above, at least one or more of the facing conductors 6 of the electron beam generating means 2 are electrically separated, and the ladder-shaped electron beam generating means 2 is electrically connected in series. Since the voltage for heating the hot cathode wire 7 does not become a low voltage of 0.1 V to 0.5 V as in the first embodiment, it is difficult to make the temperature of all hot cathode wires uniform during heating. Therefore, non-uniform brightness that occurs does not occur.

(Embodiment 3) A third embodiment of the present invention will be described below with reference to the drawings.

In FIG. 3, reference numeral 2 is an electron beam generating means, which is composed of a plurality of hot cathode lines. Reference numeral 3 denotes an electron beam control means, which is composed of a focusing electrode 3a and other electrodes 3b, 3c ... In this example. 4 is a phosphor screen. Reference numeral 5 is a spacer made of an insulating material. Reference numeral 6 is a conductor for connecting the hot cathode line. 91
Reference numerals a and 91b are connection terminals from the electron beam generating means 2. Reference numerals 10a, 10b, 10c ... Are connection terminals from the back electrode.

The electron beam control means 3 uses a plurality of plane electrodes 3a, 3b, 3c ... As insulating spacers (not shown).
It is configured to be laminated via. The electron beam generating means 2 is composed of a plurality of short hot cathode wires 7 arranged in a ladder shape or in a coil shape. The hot cathode wire 7 is usually formed by coating a fine wire of tungsten or a tungsten alloy with a carbonate such as barium.
The spacer 5 can be formed by printing a glass-based adhesive and firing it, or by spraying a ceramic.

The phosphor screen 4 is composed of red, green and blue stripes 41a, 41b and 41c arranged in parallel with the hot cathode lines. The electron beam generating means may have any of the configurations of the first and second embodiments.

The above is the same as the configuration of FIG. 1 or FIG. The difference from the configuration of FIG. 1 is that the rear electrode 11 facing the electron beam generating means 2 is provided with 11a, 11b, 11
The point is that it is configured separately from c ...

The operation of the image display device configured as described above will be described. First, in the present embodiment having the above-described structure, the back electrode 1 is composed of electrodes that are electrically separated for each of the ladder-shaped electron beam generating means, so that the back electrodes 11a, 11b, 11c ... A potential gradient is created between the electron beam generating means 3a in accordance with the image signal, and the electron beam is controlled to be emitted from the upper hot cathode line in order for a fixed time, and the emission of the electron beam from other hot cathodes is suppressed. Work. That is, the same operation as described in JP-A-57-208046 and the like is performed without applying a pulse voltage for emitting an electron beam to the hot cathode 2.

As described above, since the electron beam generating means does not have a potential gradient that causes uneven brightness, a pulse-shaped pulse is applied to the back electrode separated when the electron beam is taken out, while the voltage for heating is always applied. An electron beam can be taken out by applying a potential, and the number of terminals for the electron beam generating means can be reduced to at least two.

As described above, the electron beam generating means is composed of a plurality of short hot cathode wires arranged in a ladder or in a coil shape, and the back electrode facing the electron beam generating means is separated. With such a configuration, for example, JP-A-53-51808 and JP-A-53-12972.
It is not necessary to make the electron beam uniform by using the diode proposed in Japanese Patent Publication No. 7, and there is no problem that the number of parts increases and the circuit becomes complicated.

Although the back electrode is separated in the third embodiment, the electrode 3a facing the back electrode may be separated instead of separating the back electrode.

(Embodiment 4) A fourth embodiment of the present invention will be described below with reference to the drawings.

In FIG. 4, reference numeral 2 denotes an electron beam generating means, which is composed of a plurality of hot cathode lines. 4 is a phosphor screen. Reference numeral 5 is a spacer made of an insulating material. Reference numeral 6 is a conductor for connecting the hot cathode line. 91
Reference numerals a and 91b are connection terminals from the electron beam generating means 2.

The electron beam generating means 2 is composed of a plurality of short hot cathode wires 7 arranged in a ladder shape or in a coil shape. The hot cathode wire 7 is usually tungsten or
A fine wire of tungsten alloy is coated with a carbonate such as barium. The spacer 5 can be formed by printing a glass-based adhesive and firing it, or by spraying a ceramic.

The phosphor screen 4 is composed of red, green and blue stripes 41a, 41b and 41c arranged in parallel with the hot cathode lines. The electron beam generating means may have any of the configurations of the first and second embodiments.

The above is the same as the configuration of FIG. 1 or FIG. The difference from the configuration of FIG.
, But vertically divided into 12a, 12b, 12c ... Further, 3 is an electron beam control means, which is composed of a focusing electrode 31 and other electrodes 3b, 3c ... In this example. The electron beam control means 3 is configured by laminating a plurality of plane electrodes 31, 3b, 3c, ... Through insulating spacers (not shown). The inner plane electrodes 31 are provided in the lateral direction 31a, 3a for each electron beam generating means 2.
Pulses are applied to the electrically separated points 1b, 31c, ... And the electrodes 31a, 31b, 31c, .. Means and means for varying the voltage applied to the back electrodes 12a, 12b, 12c ... According to the luminance signal during the period.

The operation of the image display device configured as described above will be described. First, the plane electrode 31a separated in the lateral direction of the electron beam control means 3 by the above-mentioned structure.
Controls to generate an electric potential gradient between the electron beam generating means and the electron beam generating means in accordance with the image signal, and to emit the electron beam in order from the upper hot cathode line for a predetermined period of time. Further, the back electrodes 12a, 12b, 12c ... The pulsed voltage generated by pulse width modulation or voltage modulation is applied to the luminance signal of the video signal to control the electron beam emission time or the electron beam emission amount. The brightness is controlled according to. That is, unlike the configuration of Japanese Patent Laid-Open No. 57-208046, a pulse voltage for emitting an electron beam is applied to the electron beam generating means 2 in the same operation as that described in Japanese Patent Laid-Open No. 57-208046. The operation of the electron beam flow control electrodes is performed without applying the back electrodes 12a, 12b, 12c ...
・ Hold it.

[0050]

As described above, according to the first aspect of the present invention, the electron beam generating means is arranged in a ladder shape so as to correspond to the plurality of electron beam control means in parallel with the stripes of the phosphor screen between the facing conductors. It is possible to provide a high-quality image display device with uniform brightness, which can prevent vibration and can reduce the potential gradient during heating by being composed of a plurality of short hot-cathode wires arranged in a line or in a coil shape. it can.

Further, according to the present invention, at least one or more of the facing conductors of the electron beam generating means are electrically separated, and the ladder-shaped electron beam generating means are electrically connected in series so that they are electrically disconnected. By appropriately setting the locations, an appropriate voltage for heating the hot cathode lines can be obtained, the temperature of all the hot cathode lines can be made uniform, and a high-quality image display device with uniform brightness can be provided.

Furthermore, according to the present invention, at least one of the electron beam control means facing the electron beam generation means is constituted by electrodes which are electrically separated for each ladder-shaped electron beam generation means. The generating means can take out the electron beam by the other separated electrodes while always applying the voltage for heating, the number of terminals for the electron beam generating means can be reduced, and the image display device is easy to make and has high reliability. Can be provided.

Further, according to the present invention, a means for applying a pulsed voltage to the electrodes electrically separated for each of the ladder-shaped electron beam generating means and a voltage applied to the back electrode in accordance with the luminance signal during the period. By providing the variable means, it is possible to provide an image display device of uniform high image quality even at low brightness.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an image display device according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing an image display device according to a second embodiment of the present invention.

FIG. 3 is an exploded perspective view showing an image display device according to a third embodiment of the present invention.

FIG. 4 is an exploded perspective view showing an image display device according to a fourth embodiment of the present invention.

FIG. 5 is an exploded perspective view showing a conventional image display device.

[Explanation of symbols]

 1, 11, 12 Back Electrode 2 Electron Beam Generating Means 3 Electron Beam Controlling Means 4 Phosphor Screen 5 Insulating Spacer 6 Conductor 7 Hot Cathode Ray

Claims (4)

[Claims] 1. A front container provided with a phosphor screen on a transparent portion, a back container bonded to and sealed with the front container, a plurality of electron beam control means inside the front device, and a back electrode facing each other. Provided between the conductors is an electron beam generating means composed of a plurality of linear or coiled hot cathode lines arranged in a ladder shape in parallel with the stripes of the phosphor screen so as to correspond to the plurality of electron beam control means. An image display device characterized by the above. 2. An image display device, characterized in that at least one location of a conductor facing the electron beam generating means is electrically separated, and the ladder-shaped electron beam generating means is electrically connected in series. 3. The at least one electron beam control means facing the electron beam generation means is composed of electrodes electrically separated for each of the ladder-shaped electron beam generation means. The image display device according to claim 1 or 2. 4. A means for applying a pulsed voltage to the back electrode, which has an electrically separated back electrode for each of the ladder-shaped electron beam generating means, and a back electrode according to a luminance signal during the period. Means for varying the voltage applied to the
4. The image display device according to claim 3, further comprising means for varying the time of the voltage applied to the back electrode.