JPH0799680B2 - Flat panel image display device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel image display device used for a television receiver, a display for a computer terminal, and the like.

2. Description of the Related Art In recent years, flat panel image display devices have been actively developed, and liquid crystal displays (LCD), electroluminescence displays (EL), light emitting diode displays (LE) have been developed.
D) and others have appeared on the market, but they are inferior to color CRTs in terms of brightness, resolution, and full-colorization.

In order to solve these problems, the applicant of the present invention is shown in FIG.
A flat panel cathode ray tube as shown in Fig. 13 is proposed. In reality, each electrode is built in by a vacuum envelope (glass container), but the vacuum envelope is omitted in the figure to clarify the internal electrodes. Further, in order to clarify the horizontal and vertical directions of the screen for displaying images, characters, etc., the face plate portion is shown in the horizontal direction (H) and the vertical direction (V).

In FIG. 10, reference numeral 10 denotes a vertically long linear cathode in which an oxide cathode material is applied to the surface of a tungsten wire, and a plurality of linear cathodes are independently arranged at equal intervals in the horizontal direction. On the side opposite to the face plate portion 28 with the linear cathode 10 sandwiched therebetween, the linear cathode 10 is adjacent to the linear cathode 10 and is vertically elongated at a regular pitch on the insulating support 11 and is electrically separated. The scanning electrode 12 is arranged.

Next, between the linear cathode 10 and the face plate 28,
A planar first having a hole in the portion corresponding to the intersection of the linear cathode 10 and the vertical scanning electrode 12 sequentially from the linear cathode 10 side.
A grid electrode (hereinafter referred to as G1 electrode) 13, a second grid electrode (hereinafter referred to as G2 electrode) 14 having the same openings as the G1 electrode 13, and a third grid electrode (hereinafter referred to as G3 electrode) 15 are arranged. G1, G2 electrodes 13, 1
4 is for generating an electron beam from the linear cathode 10, and G3
The electrode 15 is for shielding the electric field generated by the electrode in the subsequent stage and the electric field generated by the beam.

Next, the G4 electrode 16 is arranged, and the opening thereof is longer in the horizontal direction than in the vertical direction. G4 electrode 16 has a similar opening at the latter stage 2
The vertical deflection electrodes 17 and 18 are arranged. FIG. 11 shows a horizontal section, and FIG. 12 shows a vertical section. As shown in FIG. 11, the vertical deflection electrode portion is formed by shifting the aperture central axes of the two vertical deflection electrodes 17 and 18 in the vertical direction.
In the subsequent stage of the vertical deflection electrodes 17 and 18, a plurality of vertically long electrodes are provided between the linear cathodes 10 toward the face plate portion 28. FIGS. 10 to 12 show a case of three stages as an example, in which each electrode is a first horizontal deflection electrode (hereinafter referred to as DH
1 electrode) 19, 2nd horizontal deflection electrode (hereinafter DH2 electrode) 20, 3rd
Horizontal deflection electrode (DH3 electrode hereafter) 21, each DH electrode 19-21
Are connected to the common buses 22, 23, 24 every other horizontal line. These DH electrodes 19 to 21 have a horizontal focusing function as well as a deflecting function. A light emitting layer including a phosphor screen 27 and a metal back electrode 26 is formed on the inner surface of the face plate portion 28. On the phosphor screen 27, red (R), green (G), and blue (B) phosphor stripes are sequentially formed in the horizontal direction via a black guard band.

Next, the operation of the color cathode ray tube will be briefly described.

The linear cathode 10 is heated by passing a current through it, and the same potential as that of the cathode 10 is applied to the vertical scanning electrode 12 and the G1 electrode 13. At this time, if a potential higher than the potential of the cathode 10 is applied to the G2 electrode 14 so that the beam passes through each electrode opening, the electron beam is emitted from the cathode 10 toward the G1, G2 electrodes 13, 14. It Here, the beam amount is controlled by changing the potential of the linear cathode 10 or the G1 electrode 13. The beam that passed through the aperture of G2 electrode 14 is G3
It is vertically focused by an electrostatic lens formed between the electrode 15, the G4 electrode 16, and the vertical deflection electrodes 17 and 18, and DH1 is horizontally focused.
It is focused by an electrostatic lens formed between the electrode 19, the DH2 electrode 20, and the DH3 electrode 21.

On the other hand, horizontal deflection is performed by applying a sawtooth wave, a triangular wave or the like having a horizontal scanning frequency to the common buses 22 to 24 connected to the DH electrodes 19 to 21.

The vertical scanning is performed as shown in FIGS. 13 (a) and 13 (b). The emission of the electron beam from the linear cathode 10 can be controlled by making the spatial potential surrounding the cathode positive or negative with respect to the potential of the linear cathode 10. That is, it can be controlled by switching the potential of the vertical scanning electrode 12 to a potential at which the beam is emitted (hereinafter turned on) or cut off (hereinafter turned off). In the case of the current television system adopting the interlace system, a predetermined deflection voltage is applied to the vertical deflection electrodes 17 and 18 for one field period in the first first field, and one horizontal scanning is performed on the uppermost vertical scanning electrode 12. The beam-on voltage is applied only during the period (1H below), and the beam-off voltage is applied to the vertical scanning electrodes 12 in the second and subsequent stages. After the lapse of 1H, the 1H beam ON voltage is applied only to the second-stage vertical scan electrodes 12, and thereafter, the 1H beam ON voltage is sequentially applied to the vertical scan electrodes 12. When the lowermost vertical scanning electrode 12 is completed, the vertical scanning of the first one field is completed. The second field is the vertical deflection electrode 1
The polarity of the deflection voltage applied to 7 and 18 is reversed, and this is applied for one field. The beam-on voltage applied to the vertical scanning electrodes 12 is the same as in the first field. At this time, if the amplitude of the deflection voltage applied to the vertical deflection electrodes 17 and 18 is adjusted so that the horizontal scanning line of the second field is positioned between the horizontal scanning lines of the beam in the vertical scanning of the first field. , Interlacing is possible.

Problems to be Solved by the Invention In such a configuration, as a flat panel display, in order to stably obtain an image having a uniform and sufficient brightness,
There are four problems.

(1) The first problem in that a uniform image cannot be obtained is that a linearly long linear cathode is used as an electron source.

That is, the linear cathode is stretched by a spring, but due to its length, the linear cathode vibrates in a string due to a small mechanical impact. When the linear cathode vibrates in this way, the distance from the electron beam extraction electrode fluctuates, the electric field strength changes, and the amount of the electron beam extracted fluctuates, which causes uneven brightness in the phosphor emission, resulting in image quality. Is decreasing.

Further, when the vibrated linear cathode contacts the back electrode or the electron beam extraction electrode and is electrically short-circuited, disconnection of the linear cathode occurs.

(2) The second problem that a uniform image cannot be obtained is that the image output splices blocks horizontally divided by the number of linear cathodes.

That is, one linear cathode is horizontally deflected by a slight amount.
Form one output block. When displaying an image, characters, etc. on the phosphor screen, these blocks are joined together to display the entire image. Therefore, the electron beams that horizontally scan each block must strike a defined position without overlapping or separating from each other at this joint. Therefore, the deflection waveform applied to each horizontal electrode DH1, DH2, DH3 must always be kept at a constant amplitude, but the waveform amplitude changes depending on the temperature characteristics of the electric circuit. As a result, mislanding of the electron beam occurs, causing color shift between the blocks.

In addition, in the index method adopted by this method, nonlinear phase distortion may occur in the phase of the signal that cannot be removed by the filter in the optical system and circuit system from the photoelectric conversion element to the amplifier of the beam modulation signal. is there. That is, the timing of the impact of the phosphor on the beam and the timing of applying the color signal to the beam modulation electrode do not exactly match, causing mislanding of the electron beam, and a seam between the blocks of the image appears.

(3) The third problem that a uniform image cannot be obtained is that each horizontal deflection electrode is composed of a thin film electrode formed by vapor deposition on a glass plate.

That is, when a high voltage is applied to the plate electrode by thin film deposition, field emission or fireworks discharge may occur in the vicinity of the anode end in the horizontal electrode, which may damage the high voltage application circuit or disturb the potential distribution of electrons. Beam trajectory fluctuation and image disturbance,
Problems such as brightness variations occur.

As a cause of this, the cathode side electrode is a thin film, the electric field strength of the electrode insulating part becomes large, and it becomes easy to emit electrons,
It is considered that unevenness is generated at the end of the thin film electrode formed by the vapor deposition party, and partial peeling or the like is caused, whereby local electric field concentration occurs and discharge is caused.

(4) The fourth problem that a uniform image cannot be obtained is due to the problem of atmospheric pressure due to the flattening of the vacuum container.

That is, in order to obtain a vacuum container that is lightweight and can withstand atmospheric pressure, the support member is disposed between the electrode and the face plate, so that the uniformity of the phosphors passed over the face plate is deteriorated. The support member, which is fixed to the horizontal deflection electrode and has a sharp shape on the side of the face plate, has a slight contact with the face plate side of the support member before evacuation in the manufacturing process in which the container is evacuated. However, when the container is evacuated, atmospheric pressure acts on the face plate,
The support member receives the pressure to withstand the atmospheric pressure, but at the same time, the phosphor coated on the face plate or the black stripe is pressed. When the baking process is performed in that state, the supporting member relatively moves due to the difference in thermal expansion between the glass and the metal. Then, the locus is left on the phosphor screen to deteriorate the phosphor screen.

The present invention improves the problems of the image uniformity, voltage resistance, and productivity of the above-mentioned conventional examples.

Means for Solving the Problems A thermoelectron source corresponding to the number of phosphors in the horizontal direction of a display screen is provided at the lower end of a display device, and an electron beam emitted from the thermoelectron source is diverged by a periodic magnetic field lens. Guide without. Then, the electron beam is deflected to the phosphor screen side at a desired position, and the electron beam is multiplied by the electron multiplier. The multiplied electron beam causes the phosphor provided at the final stage of the electron beam multiplier to emit light.

Action By using a periodic magnetic field lens, the electron beam is guided to the desired position without divergence, without withstanding voltage problems. The electron beam incident on the electron multiplier is multiplied, and the phosphor screen at the final stage is excited to emit light. By integrating the electron multiplier and the phosphor screen, the problems of mislanding and discharge due to geomagnetism and aging can be solved.

Example Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of the main part of the flat panel image display device in this embodiment.

That is, an electron beam generator 2 including an electron beam source using thermoelectron radiation and an electron lens system for accelerating and focusing the electron beam in the vacuum container 1, and an electron beam generated by the electron beam generator 2 at a desired position. To the face plate 6 side, an electron beam deflecting system for deflecting the induced electron beam to the face plate 6 side, and an electron beam deflecting system for amplifying the deflected electron beam. It is provided with an electron beam amplification light emitting unit 5 for emitting the fluorescent material in the steps.

Hereinafter, the electron beam generating unit 2, the electron beam guiding unit 3, and the electron beam multiplying light emitting unit 5 will be described in detail.

The electron beam generator 2 is shown in FIG. A thermal insulating layer 25 having a film thickness of 2 μm to 100 μm is provided along the bottom side on the long side of the glass substrate 21 forming the vacuum container of the flat panel display device. One end of the thermal insulation layer 25 is thicker than the other part, and the protrusion 28
Is formed. A depression 23 is provided at the tip of the protrusion 28. The cross-sectional shape of the depression 23 is a circle having a diameter of about 20 μm or a rectangle of about 10 μm * 20 μm. Inside the recess 23, the tungsten wire 22 which is a high melting point material is arranged. By passing a current through the tungsten wire 22, the oxide cathode 24 is heated. BaO, which is the oxide cathode 24, has a diameter of 10
Is attached to the tip of the nickel wire 26 having a thickness of 30 μm by electrodeposition or the like. The nickel wire 26, which is grounded via a resistor (not shown), has a length of 5 mm, and its proximal end is connected to the capacitive element or the inductive element 27 with the voltage application line for modulation as the secondary side. Are combined. The nickel wire 26 is covered with an insulating film such as alumina to prevent crosstalk.

The electron beam generator 2 is a nickel wire with an oxide cathode 24.
Except for 26, they are formed by printing or vapor deposition. A plurality of electrodes (not shown) are also formed in front of the electron beam generator 2 (on the right side in FIG. 2) by printing or vapor deposition, whereby the electron beam is accelerated to 50 to 200 eV and the divergence angle is small. It is focused on the electron beam.

FIG. 3 is a view showing an electron beam guide 3 using an electric field. That is, a substantially rectangular parallelepiped side wall 32 having a width of 30 to 50 μm and a height of 20 to 50 μm on the glass substrate 21 at intervals of about 100 μm.
However, a plurality of strips are made of a conductive material whose surface is made of aluminum, for example. On these side walls 32, a portion 33 having a small wall thickness and a portion 34 having a large wall thickness are provided in the electron beam traveling direction at a cycle of 1 mm to 10 mm. Small wall thickness
33 has a smaller wall thickness of 10 to 20 μm than the large portion 34. Due to the depression 33a formed by this, the electron beam is
It is guided to an arbitrary position without being diverged by a focusing lens that is substantially positive and negative.

In the example shown in FIG. 4, in order to further enhance the effect, a high resistance material 35 such as frit glass is installed in the depression 33a. Then, the portion 33 having a small wall thickness has a lower voltage than the other portions 34, and the high voltage and the low voltage are substantially arranged alternately in the electron beam traveling direction, and as shown in FIG. An electrostatic lens is formed, and the electron beam can travel to a desired position without diverging. The advantage of this configuration is that the high voltage part and the low voltage part can be substantially formed by one applied voltage source, and an efficient electrostatic lens can be obtained.

A voltage of 300 V is applied to the side wall (conductive layer) 32, and the resistance value is adjusted to 50 to 100 V in the relatively low voltage portion 33. Although it depends on the energy of the electron beam, for example, 100 eV can be obtained by passing a current of 1 μA to 3 μA.

FIG. 6 is a perspective view showing an electron beam guide 3 utilizing a static magnetic field, and FIG. 7 is a sectional view thereof.

That is, on the glass substrate 21, a magnetic material Gd-CO, Gd-Fe,
Alternatively, a magnetic thin film 52 made of γ-Fe ₂ O ₃ and having a thickness of 0.01 to 100 μm is formed, and is formed with an electron beam at a pitch of 1 to 10 mm.
Magnetize in the traveling direction of 53. Similarly, a magnetic thin film is provided and magnetized on the surface facing the glass substrate 21, for example, the surface of a microchannel plate (not shown). Then electron beam
The 53 moves to a desired position while receiving positive and negative forces in the X direction and repeating focused divergence. To further secure the effect, a magnetic thin film 62 may be provided and magnetized on the side surface of the beam dividing wall 61 as shown in FIG. As a means for providing these thin films, a method such as vapor deposition or printing is used. Needless to say, another magnetic recording material may be used as the magnetic material.

Generally, the magnitude of the magnetic field is B and the potential of the beam radius r = b is
Current I When Vb ^{is, I = A * b 2 *} B 2 * (Vb-CB 2 * b 2) 0.5 ( however, where, A is constant) to the current amount I exist maximum value, Imax = 16 * π * ε * (e / m) ^0.5 * Vb ^1.5 .

In this embodiment, the magnitude B of the magnetic field is 10 GAUSS to 200 GAUS.
S, when the energy of the electron beam 53 was 100 eV, the electron beam 53 of about 1 μA was transmitted without diverging.

FIG. 9 shows an electron beam amplifier and a light emitting device. That is, the frit glass 71 is applied to the entire surface of a thin metal plate having a thickness of 0.2 mm, which has three times the number of phosphor trios in the vertical direction and approximately circular holes in the horizontal direction of the number of scanning lines. A transmission electron multiplier 73 having the same number of circular shapes as that of the high resistance material and a cross section of a hole having a substantially conical shape 72 is superposed on the high resistance material which is superposed and integrated. The electron beam guided by the electron beam guide 3 using the electric field or the magnetic field is deflected at a desired position using the electrostatic or magnetic field, and enters the aperture of the electron beam multiplier 73. Then, the electron beam is multiplied while colliding with the inner wall of the aperture, enters the transmission type multiplier 73 at the final stage, and the phosphor coated in the conical opening.
Excitation 74 emits light. A so-called aqua duck is applied to the surface of the transmission type multiplier 73 on which the phosphor is applied.

According to this configuration, so-called mislanding of the electron beam does not occur. An excellent image without landing change due to the difference in thermal expansion and with time is obtained.

EFFECTS OF THE INVENTION According to the present invention, it is possible to realize a flat panel display device which has a simple structure, does not have a withstand voltage problem, and is free from deterioration of images due to geomagnetism and aging, and which can be easily enlarged.

[Brief description of drawings]

FIG. 1 is a perspective view of a flat panel image display device according to an embodiment of the present invention, FIG. 2 is an enlarged perspective view of an electron beam generator in the same embodiment, and FIG. 3 is an electron beam guiding body in the same embodiment. FIG. 4 is a perspective view, FIG. 4 is a plan view showing a first modification of the electron beam guide, FIG. 5 is an enlarged plan view of the modification, and FIG. 6 is a perspective view showing a second modification. FIG. 7 is a schematic side view for explaining the operation of the modified example, FIG. 8 is a perspective view showing a third modified example, FIG. 9 is a view showing an electron multiplier and a display section in the same example, and FIG. Is a perspective view of the prior art, FIG. 11 is a transverse plan view thereof, FIG. 12 is a longitudinal side view thereof, and FIG. 13 (a).
(B) is a side view (a) of a main part and a time chart (b) of an applied voltage for explaining the operation. 1 ... Vacuum container, 2 ... Electron beam generator, 3 ... Electron beam guide, 21 ... Glass substrate, 22 ... Tungsten wire, 27 ... Induction element, 28 ... Projection, 32 ... Side wall , 33a
…… Cavity, 35 …… High resistance material, 52,62 …… Magnetic thin film.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Masayuki Takahashi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Kiyoshi Hamada, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 72) Inventor Satoshi Kitao 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-63-228552 (JP, A)

Claims (4)

[Claims] 1. A vacuum container having at least one electron source, electron beam focusing means for focusing an electron beam emitted from the electron source, and a fluorescent display surface made of a phosphor of at least one color. In a flat-panel image display device, at least one of them is arranged substantially in the same direction as the horizontal scanning direction of the image.
For one or more electron sources, a wall made of an insulating or high-resistance material is provided over the entire length in the electron beam traveling direction over the entire number of horizontal pixels or three times the number of horizontal pixels. A flat panel image display device, characterized in that a film having magnetism is provided to form an electron beam guide body composed of a periodic magnetic field magnetized in substantially the same direction as the electron beam traveling direction. 2. The flat panel image display device according to claim 1, wherein the electron beam guide is formed by a magnetic amorphous sheet, a vapor deposition film, or printing. 3. A vacuum container having at least one electron source, electron beam focusing means for focusing an electron beam emitted from the electron source, and a fluorescent display surface made of a phosphor of at least one color. In the flat panel image display device, the electron source is provided on a heat insulating protrusion provided on one end side of the glass substrate, and the high melting point material provided on the protrusion heats the electron source. On the other hand, the electron beam amount of the electron source is controlled by inputting a signal to the electric circuit coupled with the thermally insulated capacitive or dielectric element. A flat panel image display device characterized by: 4. A vacuum container having at least one electron source, electron beam focusing means for focusing an electron beam emitted from the electron source, and a fluorescent display surface made of at least one color phosphor. In a flat-panel image display device, at least one of them is arranged substantially in the same direction as the horizontal scanning direction of the image.
For one or more electron sources, a wall made of an insulating or high resistance material is provided over the entire length in the electron beam advancing direction over the entire number of horizontal pixels or three times the number of horizontal pixels, and the wall is made of a conductive material. Along with the formation, a recessed portion is provided on the wall surface in the arrangement direction of this wall in the electron beam traveling direction,
A flat panel image display device, characterized in that a periodic electric field is formed by providing a resistor in the depressed portion so that the voltage is relatively lower than that of other portions.