JP3063647B2 - Fluorescent display tube and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a fluorescent display tube having a wire grid composed of a large number of fine metal wires and performing desired graphic display, and a method of manufacturing the same.

[0002]

2. Description of the Related Art FIGS. 3 and 4 show an example of the configuration of a conventional general fluorescent display tube for performing graphic display.
A plurality of strip-shaped anodes 24 to which phosphors 23 are attached are formed at predetermined intervals on a substrate 22 forming a part of a box-shaped envelope 21. In the envelope 21, a wire grid 25 composed of a plurality of fine metal wires is stretched over the anode 24 in a direction crossing the anode 24. Above the wire grid 25, a filament-shaped cathode 26 for emitting electrons is provided.

In the fluorescent display tube configured as described above, two adjacent wire grids 25 are scanned while being shifted one by one, and a display signal synchronized with the scanning is supplied to the anode 24. When electrons are emitted from the filament-shaped cathode 26, the emitted electrons impinge on a small region on the anode 24 sandwiched between the two wire grids 25, causing the phosphor 23 to emit light. The desired graphic display is obtained.

By the way, the wire grid 25 in this type of fluorescent display tube has a distance H between the anode 24 of 0.15 and 0.
It is set to a constant value of 4 mm (for example, 0.2 mm) and is stretched on the substrate 22.

When the distance H between the anode 24 and the wire grid 25 is small, electrons converge and the brightness of the portion of the anode 24 becomes higher than that of the other anode 24 portions.
On the other hand, when the value of the distance H is large, the anode 24
Part of the electrons are diffused, and the luminance is lower than that of the other anode 24 parts. Thus, the anode 24 and the wire grid 2
Since the difference in the distance H from the anode 5 directly affects the brightness of the portion of the anode 24, it is necessary to keep the height of the wire grid 25 between each portion of the anode 24 constant.

Therefore, in a conventional fluorescent display tube, as shown in FIGS. 3 and 4, a wire is provided by a spacer glass 28 positioned at both ends of a substrate 22 via stoppers 27 in parallel with a band-like anode 24. A structure in which both ends of the grid 25 are floated from the substrate 22 at a predetermined height and stretched has been adopted.

More specifically, the stopper 27 is made of a pair of low-melting glasses formed at both ends of the substrate 22 at predetermined intervals so as to regulate the positions of both sides of the spacer glass 28. The distance between the stoppers 27 is
The width is set slightly larger than the width of the spacer glass 28. A pair of stoppers 27 made of low-melting glass are placed on the substrate 22 in parallel with the strip-shaped anode 24 on the spacer glass 28.
And is pre-baked so that the phosphor 23 forming the anode 24 does not adhere.

Then, the wire grid 25 is connected to the substrate 22.
In the case of stretching over, a spacer glass 28 is placed between a pair of stoppers 27 made of preliminarily fired low-melting glass. In this state, the wire grid 25 is placed on the spacer glass 28. Then, the front plate 30 and the side plate 31
Is placed on the substrate 22 and baked by heating;
The outer periphery of the container 32 is sealed. Thereby, the wire grid 25 is stretched on the substrate 22 while the height from the anode 24 is kept constant by the spacer glass 28.

[0009]

However, the above-mentioned conventional fluorescent display tube has the following various problems. Since the spacer glass 28 used for holding the wire grid 25 at a constant height has a small thickness, it is necessary to perform a certain process for making the thickness constant, for example, a flow process, and the spacer glass 28 itself is used. Is formed of special glass, so that there is a problem that the cost increases.

The width of the spacer glass 28 is required to be at least 2 to 3 mm in consideration of the handleability when automatically mounted on the substrate 22, and if the spacer glass 28 is formed thinner than this value, the handleability deteriorates. In addition, there are problems such as difficulty in handling, cracking and breakage.

The substrate 22 on which the spacer glass 28 is placed
Since a pair of stoppers 27 for preventing the displacement of the spacer glass 28 are separately formed at both ends of the above, there is a problem that the number of working steps is increased by that amount. Moreover, the spacer glass 28 has a thickness of 2 to 3 mm, and each stopper 27 has a thickness of 1 to 2 m.
m installation space is required. For this reason, the anode 24 located on the outermost edge from the inner wall surface of the side plate 30 is provided on the substrate.
In this case, the distance L3 must be at least 6 mm or more, which requires a space for disposing the space, resulting in a dead space on the display surface.

Since the spacer glass 28 is not completely fixed to the substrate 22 until the container portion 31 is sealed to the substrate 22 after the firing step, the spacer glass 28 is displaced by an external impact during transportation or the like. The distance H between the anode 24 and the wire grid 25 may be out of order.

The wire grid 25 is stretched on the substrate 22 with both ends held at a constant height by a spacer glass 28. Since the spacer glass 28 has a prismatic shape, the angle at which the wire grid 25 contacts the wire grid 25 is increased. The portions are rubbed by the tension of the wire grid 25 to generate powdery glass dust, which becomes dust and degrades the display quality and quality, thereby causing a defective fluorescent display tube.

In view of the above, the present invention has been made in view of the above-mentioned problems, and the cost can be reduced by reducing the number of components, the dead space on the display surface can be reduced, and the displacement due to external impact can be reduced. It is an object of the present invention to provide a fluorescent display tube which can be manufactured without causing the display quality and the display process to be simplified without deteriorating the display quality and quality, and a method of manufacturing the same.

[0015]

In order to achieve the above object, a first aspect of the present invention is to form a box-shaped envelope comprising a substrate and a container portion and a surface of the substrate in the envelope. An anode having a phosphor, and a fluorescent display tube having a plurality of wire grids facing the anode and stretched at predetermined intervals on the substrate in the envelope at a predetermined distance, The anode is formed in a band shape in a direction intersecting with the wire grid, and contains a crystallized glass as a main component, a low melting point glass having a high softening point, a pigment, and a mixed material of a vehicle and the mixed material in the envelope. A grid spacer made of an insulating member printed and fired on the surface of the substrate, the anode and the side plate located at the outermost edge of the anode with a contact surface in contact with both ends of the wire grid having a curved shape. Before Characterized in that it is printed on the projections on the surface of the substrate.

A second aspect of the present invention is a box-shaped envelope including a substrate and a container, an anode having a phosphor formed on the surface of the substrate in the envelope, and facing the anode. And a method for manufacturing a fluorescent display tube having a plurality of wire grids stretched at predetermined intervals on the substrate in the envelope at a predetermined distance, comprising a crystallized glass as a main component, a softening point A low-melting glass having a high content, a pigment, and a paste-like insulating member made of a mixed material of a vehicle are formed by printing on the surface of the substrate, and then the insulating member is fired and crystallized to form a grid spacer. The plurality of wire grids are arranged so as to be in contact with the upper surface of the grid spacer, and a lid comprising a front plate and a side plate in a state where tension is applied to each of the wire grids. Characterized in that it comprises a step of sealing the outer peripheral portion by placing the container unit on the substrate.

According to a third aspect of the present invention, in the method for manufacturing a fluorescent display tube according to the second aspect, the insulating member is 440-56.
It is characterized by being fired at 0 ° C.

[0018]

[0019]

[0020]

[0021]

[0022]

FIG. 1 is a partially enlarged plan sectional view of a fluorescent display tube showing an embodiment of the present invention when viewed from above.
FIG. 2 is a partially enlarged sectional view of the fluorescent display tube of FIG. 1 as viewed from the side.

The fluorescent display tube according to this embodiment has an envelope 1 whose inside is maintained in a high vacuum state, and has a structure in which various electrodes and the like are housed.

The envelope 1 is composed of a substrate (anode substrate) 2 and a lid-like container portion 5 composed of a front plate 3 and side plates 4. On the inner surface of the substrate 2, a base seal 6 for sealing is continuously provided in a frame shape on an outer peripheral portion serving as a sealing portion of the envelope 1. As the base seal 6, a paste-like low-melting glass is used, and after being printed in a frame shape on the outer peripheral portion of the envelope 1, it is temporarily fired.

On the inner surface of the substrate 2, a plurality of strip-shaped anodes 7 are formed at predetermined intervals along the longitudinal direction. Each anode 7 includes an anode conductor 7a formed on the substrate 2 and a phosphor 7b adhered to the anode conductor 7a.

The anode conductor 7a is formed of an Al thin film when forming a fluorescent display tube for observing display from the front panel 3 side, and constitutes a fluorescent display tube for observing display from the substrate 2 side. In this case, the light-transmitting ITO thin film is used. Although the phosphor 7b is shown as being solidly formed on the anode conductor 7a, it may be partially (for example, every other interval of the wire grid 9) if it corresponds to the interval of the wire grid 9 described later. ) May be formed.

As shown in FIG. 1, convex grid spacers 8 are formed on the surfaces of both sides of the substrate 2 which are separated from the inner wall surface of the longitudinal side plate 4 by a predetermined distance L1 inside. More specifically, the grid spacer 8 is formed of a printed pattern made of an insulating material, and is formed in parallel with the anode 7 between the anode 7 located at the outermost edge and the side plate 4 at a predetermined distance L2. The grid spacer 8 is made of crystallized glass as a material, and is formed into a paste by mixing low melting glass, a vehicle, and a pigment. The grid spacer 8 is improved in contrast by being blackened using a black pigment.

When the grid spacers 8 are formed of only crystallized glass when viewed as a solid content, the gas of the vehicle is difficult to escape, and projections are generated by air bubbles to impair the uniformity of the height. % And the remaining 10%
Is composed of a low-melting glass having a softening point as high as 500 ° C. or higher.

When the grid spacer 8 is formed on the substrate 2, a screen printing method is applied. At this time, a metal screen made of a thin metal plate is used as the screen. The metal screen has an opening formed by etching into the outer shape of the grid spacer 8.

When the grid spacer 8 is formed on the substrate 2, the metal screen is placed on the substrate 2 with the opening positioned at the position where the grid spacer 8 is formed.
A paste-like material (a mixture of crystallized glass, low-melting glass, vehicle and pigment) is applied so as to fill the opening, and the excess material protruding from the opening is removed along the surface of the metal screen. The surface of the material in the opening is flush with the surface of the metal screen.

Thus, the grid spacer 8 in the form of a prism is paste-printed at a predetermined position on the substrate 2. In this state, since the grid spacer 8 is in a paste state, it is then fired at 440 to 560 ° C. to completely crystallize. As a result, the grid spacer 8 is fixed on the substrate 2 without re-melting in the firing step when assembling the fluorescent display tube.

Here, the grid spacer 8 has a uniform height due to the thickness of the metal screen. However, when the grid spacer 8 is fired and crystallized from a paste state, the surface is reduced to a certain degree. This results in a curved surface shape as shown in FIG. For this reason, the thickness of the metal screen is set in consideration of the reduction during firing so that a desired height is obtained when the grid spacer 8 is crystallized.

Above the anode 7 in the envelope 1, a wire grid 9 composed of a plurality of thin metal wires is provided at predetermined intervals in a direction intersecting with the anode 7 (in the drawing, a direction orthogonal to the anode 7).
Is stretched. More specifically, each wire grid 9 has both ends in contact with the surface of the grid spacer 8 and the distance H between the wire grid 9 and the anode 7 is constant (0.15 to 0.4).
(for example, 0.2 mm) is stretched on the substrate 2. Above the wire grid 9,
A filament-shaped cathode 10 for emitting electrons is provided.

In the fluorescent display tube having the above configuration, two adjacent wire grids 9 are scanned while being shifted one by one, and a display signal synchronized with the scanning is supplied to the anode 7. Then, when electrons are emitted from the filament-shaped cathode 10, the emitted electrons are combined with the two wire grids 9.
The fluorescent substance 7b emits light by colliding with the small area on the anode 7 sandwiched between the two, and a desired graphic display is obtained.

Next, a description will be given of a method of manufacturing the fluorescent display tube configured as described above. First, the substrate 2 on which the anode 7 is formed is washed. Next, a wiring conductor and a plurality of strip-shaped anode conductors 7a are formed on the upper surface of the substrate 2 with an Al thin film by photolithography. A base seal 6 as a sealing material is attached in a frame shape around the upper surface of the substrate 2 by a printing method. The base seal 6 is pre-fired so that the phosphor 7b does not adhere. Next, the anode conductor 7 is formed by a printing method.
A band-shaped anode 7 is formed by depositing a phosphor 7b on a.

Next, grid spacers 8 are formed on the surfaces of both sides of the substrate 2 at a predetermined distance L1 inward from the inner wall surface (base seal 6) of the side plate 4 by the screen printing method described above. Since the grid spacer 8 formed by printing is in the form of a paste, the grid spacer 8 is formed in the form of 440-5
It is baked at 60 ° C., completely crystallized, and fixed on the substrate 2.

Next, the wire grid 9 attached to the jig
Are arranged so as to be in contact with the upper surface of the grid spacer 8 and are pulled outward to give a predetermined tension. In this state, the position of the substrate 2 is adjusted in order to align the wire grid 9 mounted on the jig side with the pattern of the band-shaped anode 7. Next, a filament-shaped cathode 10 is stretched above the wire grid 9. Then, a lid-shaped container portion 5 composed of the front plate 3 and the side plate 4 is placed on the substrate 2, heated and baked, and sealed with a base seal 6.

As described above, according to the above embodiment, each wire grid 9 is connected to the grid spacer 8 mainly composed of crystallized glass fixed to the substrate 2 while the anode 7 is in contact with both ends. Is stretched on the substrate 2 while keeping the distance H between them constant.

Therefore, since only the grid spacer 7 is required to hold the wire grid 9 at a constant height, the number of components is reduced as compared with the conventional fluorescent display tube shown in FIGS. The cost can be reduced and the configuration can be simplified. In addition, due to the reduced number of components, the anode 7 located at the outermost edge from the inner wall surface of the side plate 4
The distance L3 to 6mm or less from the conventional 6mm,
The dead space on the display surface can be reduced to 1/3 or less of the conventional fluorescent display tube.

When the display area has the same size as that of the conventional fluorescent display tube, the outer dimensions of the envelope 1 are reduced by the reduced dead space on the substrate 2 as compared with the conventional fluorescent display tube. The size can be reduced, and the size of the fluorescent display tube can be reduced.

Since the grid spacer 8 is crystallized and adhered and fixed on the substrate 2, it does not melt again in the firing step when assembling the fluorescent display tube. There is no displacement of the grid spacer 8 due to an external impact before the enclosure 1 is sealed.

Further, in the conventional fluorescent display tube, after forming a pair of stoppers on the substrate, spacer glass is arranged between the stoppers and the wire grid is imposed. After the grid spacer is printed and formed, the wire grid 9 can be imposed,
Compared with the conventional fluorescent display tube, the number of operation steps can be reduced and the operation can be simplified.

When the grid spacer 8 is crystallized and fixed on the substrate 2, the surface has a curved shape. Therefore, even if the grid spacer 8 is rubbed by the tension of the wire grid 9, it is difficult for dust to be generated. And the degree of occurrence of defective products due to deterioration in quality and quality can be significantly reduced as compared with the conventional case.

[0044]

As is apparent from the above description, according to the present invention, only the grid spacers are required to hold the wire grid at a fixed height, and therefore, the components are smaller than those of the conventional fluorescent display tube. The number of points can be reduced, the material cost can be reduced, and the configuration can be simplified. In addition, the dead space on the substrate can be reduced by the reduced number of components compared to the conventional fluorescent display tube.

Since the grid spacer is crystallized and attached and fixed on the substrate, it does not re-melt in the firing step when assembling the fluorescent display tube, and after the wire grid has been imposed, the envelope has not been melted. There is no displacement of the grid spacer due to an external impact before sealing.

Since the surface of the grid spacer has a curved shape, it is difficult to generate debris even if the grid spacer is rubbed by the tension of the wire grid. It can be significantly reduced.

In the conventional fluorescent display tube, after forming a pair of stoppers on the substrate, a spacer glass is arranged between the stoppers and the wire grid is imposed. However, after the grid spacer is printed and formed on the substrate, the wire grid is formed. Since the grid can be imposed, operation steps can be reduced and the operation can be simplified as compared with the conventional fluorescent display tube.

[Brief description of the drawings]

FIG. 1 is a partially enlarged plan sectional view of a fluorescent display tube according to an embodiment of the present invention when viewed from above.

FIG. 2 is a partially enlarged cross-sectional view of the fluorescent display tube of FIG. 1 as viewed from the side.

FIG. 3 is a partially enlarged plan sectional view of a conventional fluorescent display tube when viewed from above.

FIG. 4 is a partially enlarged cross-sectional view of the fluorescent display tube of FIG. 3 viewed from a side.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Envelope, 2 ... Board, 3 ... Front plate, 4 ... Side plate, 5 ...
Container part, 7 ... Anode, 7b ... Phosphor, 8 ... Grid spacer, 9 ... Wire grid.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H01J29 / 29 / H01J29 / 46Z (72) Inventor Hiroyuki Watanabe 629 Oshiba, Mobara-shi, Chiba Futaba Electronics Industry Co., Ltd. (72) Inventor Hiroyuki Iwase 629 Oshiba, Mobara-shi, Chiba Futaba Electronics Co., Ltd. (56) References JP-A-61-250943 (JP, A) JP-A-63-105448 (JP, A) JP-A-2-186542 ( JP, A) JP 6-11251 (JP, U) JP 6-38150 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 31/15 H01J 9/02 H01J 9/14 H01J 29/10 H01J 29/46

Claims (3)

(57) [Claims] 1. A box-shaped envelope comprising a substrate and a container, an anode having a phosphor formed on a surface of the substrate in the envelope, and a predetermined distance facing the anode. A plurality of wire grids stretched at predetermined intervals on the substrate in the envelope, wherein the anode has a band shape in a direction intersecting with the wire grid.
It is formed on, composed mainly of crystallized glass, high softening point low-melting glass
, A pigment, and a mixed material of the vehicle in the envelope.
From the insulating member printed and fired on the surface of the substrate
Grid spacers at both ends of the wire grid
The contact surface that contacts the part has a curved shape and
Surface of the substrate between the anode located at the edge and the side plate
A fluorescent display tube characterized by being printed and formed on a ridge . 2. A box-shaped envelope comprising a substrate and a container part.
And a phosphor formed on the surface of the substrate in the envelope
And an anode having a predetermined distance and facing the anode.
Are stretched at predetermined intervals on the substrate in the envelope.
Of a fluorescent display tube having a plurality of wire grids
In production method, as a main component crystallized glass, high softening point low-melting glass
, Pigment, and paste made of mixed material of vehicle
After printing and forming an insulating member on the surface of the substrate,
The grid spacer, which is made by firing and crystallizing the insulating member,
Formed on the surface of the substrate, and
Arrange the plurality of wire grids so that they touch the surface
And tension is applied to each of the wire grids.
The lid-shaped container portion consisting of the front plate and side plate
The method includes a step of sealing the outer peripheral portion on a substrate.
The method of manufacturing a fluorescent display tube. 3. The method according to claim 1, wherein the insulating member is heated at 440 to 560.degree.
3. The method according to claim 2, wherein the display is fired.