JP2002298767A - Fluorescent display tube and its driving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent display tube and its driving method capable of suppressing a leaking light emission even in case the display pattern is large. SOLUTION: To a printed wiring 36x for an anode, only a phosphor layer 22R within the control unit G1 is connected, while a plurality of phosphor layers 22S or ones 22L having different control units G from each other are connected with a plurality of printed wirings 36a-36i for anode which are independent of the first named wiring 36x and also of one another. Accordingly the phosphor layer 22R is electrically independent of the other phosphor layers 22S and ones 22L connected with the printed wirings 36a-36i for anode, so that the driving voltage can be impressed only in the period the phosphor layer 22R should emit light regardless of the light emitting timing of the other phosphor layers 22S and 22L.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a fluorescent display tube and a driving method thereof.

[0002]

2. Description of the Related Art A plurality of anodes each having a phosphor layer provided on a surface thereof in a predetermined display pattern, and rib-like walls projecting so as to surround the plurality of phosphor layers, respectively, are formed on an anode substrate. The phosphor layer is provided on a display surface and controlled by a grid electrode (control electrode made of a conductive film) provided on the top of the rib-like wall to control electrons generated from a filament-like cathode provided in a vacuum space. Vacuum Fluorescen
t Display: VFD) is known. For example, JP-A-8
Such a fluorescent display tube is described in, for example, JP-B-138590.

[0003] Such a fluorescent display tube has a low operating voltage and is clearly displayed because a phosphor layer to which electrons generated from a cathode collide is provided in the vicinity of the cathode, and emits light of different colors from each other. There is a feature that color display is possible by preparing a plurality of types of phosphors. For this reason, it is frequently used as a display component of a display panel of an audio equipment, a car or an aircraft. In addition, since the grid electrode is formed of a conductor film provided on the top of the rib-shaped wall, a mesh-shaped grid electrode covering the phosphor layer is not used. Display defects such as uneven brightness and short-circuits due to thermal deformation of the grid electrode when the grid electrode is enlarged, and a decrease in the brightness of the fluorescent display tube in relation to the aperture ratio of the grid electrode are solved. There are advantages such as.

[0004]

By the way, in a fluorescent display tube provided with a large number of anodes for displaying various light emission patterns, it is necessary to suppress an increase in the number of anode wirings and hence an increase in the number of driving drivers. For the purpose, a plurality of anodes surrounded by different grid electrodes are connected to a common anode wiring. The fluorescent display tube in which the anode substrate is configured in this manner scans while applying a positive control voltage to the grid electrode in a state where the thermoelectrons are emitted by the current flowing through the filamentary cathode, and the scanning is performed. When a positive drive voltage is applied to the anode wiring to which the phosphor layer to be made to emit light is connected in synchronization with the scanning timing, light emission display is performed in a desired pattern by so-called dynamic drive.

However, in the rib-grid type fluorescent display tube, since the grid electrode is provided only on the outer peripheral edge of the display pattern, it is formed as the distance from the grid electrode increases toward the inner peripheral side. The electric field strength decreases. Therefore, in the dynamic driving method as described above, a driving voltage is also applied to the phosphor layer that does not emit light, and the light emission is controlled by applying a cutoff bias (negative control voltage) to the grid electrode. Therefore, as the size of the display pattern increases, it becomes more difficult to control the thermoelectrons in the inner peripheral portion thereof, and there is a disadvantage that light emission may leak. In addition, if the display pattern is divided into small patterns of a size that can provide a sufficient control function and individually configured to be surrounded by grid electrodes, such a disadvantage does not occur, but in order to maintain the design of the light emitting pattern. In many cases, the division is not preferable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fluorescent display tube capable of suppressing leakage light emission even when a display pattern is large, and a driving method thereof. is there.

[0007]

In order to achieve the above object, the gist of the first aspect of the present invention is to provide a fluorescent display tube in which a plurality of fluorescent layers are provided on the surface in a predetermined display pattern. A plurality of anodes, a rib-shaped wall projecting so as to surround each of the plurality of phosphor layers, and a plurality of control electrodes provided for each predetermined control unit on the top of the rib-shaped wall. Provided on the display surface, a fluorescent display tube of a type in which electrons generated from a cathode provided above the phosphor layer in a vacuum space are controlled by the control electrode to emit light from the phosphor layer, (a) a first anode wiring in which only a predetermined anode in one control unit of the plurality of anodes is connected, and (b) a plurality of anodes having different control units from each other are connected. And electrically independent of the first anode wiring and independent of each other. A second anode wire a plurality of,
To include.

[0008]

According to a second aspect of the present invention, there is provided a method of driving a fluorescent display tube, wherein the control units are sequentially selected and scanned. A positive control voltage is applied to the plurality of control electrodes for each control unit, and a positive drive voltage is applied to the first anode wiring and the plurality of second anode wirings in synchronization with the scanning. The method of driving the fluorescent display tube according to claim 1, wherein (a) applying a positive drive voltage to the first anode wiring only during a period in which the one control unit is selected. is there.

[0009]

In this way, while only the predetermined anode in one control unit is connected to the first anode wiring, a plurality of first anode wirings independent of the first anode wiring and mutually independent are provided. 2
A plurality of anodes each having a different control unit are connected to the anode wiring. Therefore, the fluorescent display tube is driven by so-called dynamic driving. However, since the predetermined anode is electrically independent of the other anode connected to the second anode wiring, the light emission formed by the other anode is performed. Regardless of the light emission timing of the pattern, the drive voltage can be applied only during a period in which the light emission pattern formed by the predetermined anode is to emit light. That is, the predetermined anode is substantially driven by the static drive in which a positive drive voltage is applied to the first anode wiring for a period during which one control unit is selected, and the display surface is driven by the static drive. A display pattern is provided in a mixed manner with a display pattern driven by dynamic driving. As described above, for a predetermined anode, that is, a display pattern that is statically driven,
Leakage light emission caused by application of the drive voltage during non-light emission is suitably suppressed.

[0010]

In this case, preferably, the predetermined anode connected to the first anode wiring is provided in a shape which is sufficiently wide with respect to the control ability of the control electrode. . With this configuration, the predetermined anode is connected to the first anode wiring independent of the other anodes, so that no driving voltage is applied during the non-emission period, so that the thermoelectron control of the control electrode is insufficient. Even if there is, no leakage light emission due to it will occur. Here, “sufficiently wide for the control capability” means that a negative electric field formed when a cut-off bias is applied to the control electrode becomes insufficient in the inner peripheral portion of the anode, and It means that the distance between the grid electrodes facing each other across the phosphor layer is large enough to prevent thermal electrons from being incident on the phosphor layer at the inner peripheral portion during the light emission period and to cause leakage light emission. The size of the phosphor layers having such an interval is, for example, in the case of a square or circular phosphor layer, the length or diameter of one side thereof is about 0.6 (mm) or more, In the case of a rectangular shape (or a band shape) having a dimension of 0.5 (mm) or more, its short side dimension is about 0.4 (mm) or more.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a perspective view of a rib-grid type fluorescent display tube 10 according to an embodiment of the present invention, with a part thereof being cut away. In the figure, a fluorescent display tube 10 is provided with a substrate 12 made of an insulating material such as glass, ceramics, or enamel provided with a plurality of phosphor layers 20 _S , 20 _R described later formed in a predetermined light emitting pattern at a plurality of locations, A glass spacer 14 formed in a frame shape, a transparent cover glass plate 16, a plurality of anode terminals 18 _P , a plurality of grid terminals 18 _G , an auxiliary grid terminal 18 _SG , and a cathode terminal 18 _K are provided. The substrate 12, the spacer 14, and the cover glass plate 16 are mutually sealed with glass to form an airtight container, and a vacuum space surrounded by these members is formed therein. I have. In this embodiment, the substrate 12 corresponds to an anode substrate.

One of the substrates 12 covered by the vacuum space
The surface 20 functions as a display surface of the fluorescent display tube 10
Where there are 7 segments representing the “8” character shape.
A plurality of phosphor layers 22_S, And one representing a rectangular shape
Phosphor layer 22_REtc. are arranged, each character etc.
It constitutes a light emitting unit for displaying. Phosphor layer 22
_SThe width of each segment is, for example, about 0.4 (mm),
Phosphor layer 22_RIs about 5 × 4 (mm), for example.
Each of the phosphor layers 22_S, 22_RIs the length of the substrate 12, for example.
It is set for each of the objects that are located at approximately the same position in the hand direction.
Grid electrodes 24 provided for each light emitting unit.
Each of the grid electrodes 24 has a phosphor
Layer 22_SIs provided around the
Surrounded by the auxiliary grid electrode 26 which is electrically insulated.
ing. Phosphor layer 22_RSize, especially the length of the short side
Is sufficiently large for the control capability of the grid electrode 24.
The electric field generated by the phosphor layer 22_RIn the inner circumference of
It is large enough to be of insufficient strength.

The auxiliary grid electrode is shown in FIG.
26 are provided in common on the entire surface.
A separate auxiliary grid electrode to the grid surrounding the pattern.
May be provided in a state of being electrically connected to the gate electrode 24. Ma
In the figure, the phosphor layer 22_SAuxiliary grid electricity surrounding
Only the pole 26 is shown, but the other phosphor layers 22_REtc.
The auxiliary grid electrode 2 is also provided at an appropriate position as necessary.
Auxiliary grid electrode connected to or independent of 6
Is provided. In addition, each of the above-described phosphor layers 22 _S, 2
2_ROf the predetermined positions for each display digit
Is connected to each anode terminal 18 via an anode printed wiring 36 described later.
_PAnd the grid electrodes 24 are connected to
Grid terminals 18 via_GTo each
Each auxiliary grid electrode 26 is connected to an auxiliary grid wiring.
30 via each auxiliary grid terminal 18_SGConnected to
You.

The grid electrode 24 surrounding the rectangular phosphor layer 22 _R has a “8” character-shaped phosphor layer 22 formed at a lower position in FIG. _The grid electrodes 24 surrounding _S are connected to a common grid wiring 28, and these grid electrodes 24 are substantially one electrode. On the other hand, the grid electrode 24 surrounding another relatively large “8” character-shaped phosphor layer 22 _S is connected to a separate grid wiring 28. In the present embodiment, a control unit is formed for each grid electrode 24 sharing the grid wiring 28, and a large "8" character shape belongs to an independent control unit, but a small "8" character shape. Belongs to the same control unit as the rectangular one. Further, the latter control unit of the small “8” character shape and rectangular phosphor layer 22 corresponds to “one control unit” in the claims.

[0016] On both ends of the substrate 12, the cathode terminal 18 a pair of filament support frame 32 having a _K (shown only one located on the right side in the figure) are fixed respectively, their filaments A plurality of thin filaments (filament / cathode) 34 functioning as a directly heated cathode (cathode) are parallel to the longitudinal direction of the substrate 12 and are separated from the display surface 20 of the substrate 12 between the support frames 32. It is stretched so as to be at a predetermined height position.

For this reason, the thermoelectrons emitted from the filament 34 are accelerated by the grid electrode 24 to which a positive voltage (acceleration voltage) of, for example, about 20 (V) is applied to the zero (V) filament 34. Therefore, when a positive voltage is also applied to the phosphor layer 22 surrounded by the grid electrode 24, thermions collide with the phosphor layer 22 to cause the phosphor layer 22 to emit light. Even if a positive voltage is applied to the body layer 22, if a negative bias voltage (cutoff bias) of about several volts is applied to the filament 34 to the grid electrode 24 surrounding the body layer 22, the thermoelectrons emit fluorescent light. The phosphor layer 22 does not emit light without reaching the body layer 22.
Therefore, due to the flow of electrical current to the filament 34 in a state in which thermal electrons emitted, the grid electrode 24 in synchronism with the positive voltage is sequentially applied, said respective phosphor layers 22 _S, 22 _R When a positive voltage is also applied to the desired one, light-emitting display is performed in a desired pattern by so-called dynamic driving.

At this time, although a cut-off bias is applied to the grid electrode 24 to which no acceleration voltage is applied, a common auxiliary grid electrode 26 has a positive voltage similar to the acceleration voltage applied to the grid electrode 24, for example. A voltage (auxiliary acceleration voltage) is constantly applied to make the potential constant. That is, the grid electrode 24 to which the acceleration voltage has been applied is surrounded by the auxiliary grid electrode 26 to which the auxiliary acceleration voltage has been applied, and the phosphor layer 22 has the grid electrodes 24, 2
6 are doubly enclosed. For this reason, since the negative electric field formed by the grid electrode 24 to which the cutoff bias is applied is canceled by the auxiliary grid electrode 26, the electron flow toward the desired phosphor layers 22 _S and 22 _R to be emitted is reduced. No longer disturbed by the negative electric field,
Light emission unevenness of the phosphor layer 22 is suitably suppressed.

[0019] In this drive control, the inner circumference from that control capability of the grid electrode 24 surrounding it with respect to the size of the phosphor layer 22 _R as described above is insufficient, the phosphor layer 22 _R in part, be applied cutoff bias around the grid electrode 24, the leakage light emission may occur not when a positive voltage is applied the electrons incident is prevented in the phosphor layer 22 _R. However, in the present embodiment, since there is no possibility that a positive voltage is applied within the time cutoff bias around the grid electrode 24 is applied to the phosphor layer 22 _R, no such leakage light emission . Hereinafter, a substrate structure for such driving, particularly, a wiring structure will be described in detail.

FIG. 2 shows the above-described rectangular phosphor layer 22 _R and the figure-shaped phosphor layer 22 of the light emitting units (display patterns) of the fluorescent display tube 10 provided on the display surface 20 of the substrate 12. FIG. 3 is an enlarged view showing a portion provided with _S , and FIG. 3 is a cross-sectional view taken along aa line in FIG.
This is a further enlarged cross-sectional view as viewed in b. Note that FIG.
The size ratios of FIGS. 2A and 2B do not match each other.

In FIG. 2, the display surface 2 of the substrate 12
0, the thick film conductor paste is screen printed
15 anode printed wiring to be connected to the anode terminal 18 _P by being printed on ([mu] m) thickness on the order of being and calcined 3
6, an insulator layer 40 formed to a predetermined thickness and appropriately provided with a through hole 38 penetrating in the thickness direction is fixed thereon. As shown in FIG. 4 to be described later, those connected to the phosphor layers 22 _S of each segment of the "8" characters shape of the anode for printed wiring 36, the corresponding position constituting the other "8" character form , But those connected to the rectangular phosphor layer 22 _R are not connected to any of the other phosphor layers 22. The insulator layer 40 is formed by applying a thick-film insulating paste composed of a low-melting glass and a coloring pigment by a screen printing method.
It is formed by applying and firing at a thickness of about 30 to 40 (μm). The pad to which the wiring 36 and the anode terminal _18P are connected may be provided by etching a vapor-deposited aluminum thin film, for example, instead of being provided by screen printing.

On the insulator layer 40, the phosphor layer 22
A graphite layer 42 having a pattern shape similar to or slightly larger than that described above is formed at a position where the graphite layer 42 is electrically connected to the anode printed wiring 36 via the through hole 38. The graphite layer 42 is formed by printing and firing a thick film paste mainly composed of graphite in a predetermined pattern so as to have a thickness of about 40 (μm).
Functions as an anode. In the present embodiment, strictly speaking, in the “8” character-shaped pattern, a portion of the graphite layer 42 located directly below the phosphor layer 22 _S functions as an anode, and the “8” character-shaped fluorescent portion protruding from the body layer 22 _S to the outer side 44 functions as a peripheral electrode. Each phosphor layer 22 is formed of, for example, the graphite layer 42.
Is formed by printing a thick-film phosphor paste on the substrate.

A thick-film glass material-like rib-like wall 46 in contact with and surrounding the outer peripheral edge of the phosphor layer 22 by printing a thick-film paste is formed around the phosphor layer 22 or the graphite layer 42. On the insulator layer 40, it is erected in a direction away from the substrate 12, that is, in a direction toward the filament 34. In the figure-shaped pattern, the auxiliary layer made of a thick film glass material is also in contact with and surrounding the outer peripheral edge of the graphite layer 42 and at a predetermined interval on the outer peripheral side of the rib-like wall 46. A rib-like wall 48 stands on the insulator layer 40. The grid electrode 24 and the auxiliary grid electrode 26 are thick film conductors mainly composed of particulate conductive substances such as graphite, silver, palladium, copper, aluminum and nickel. By printing and firing at the same time, a thickness of about 10 to 50 (μm) is provided on the tops of the rib-like wall 46 and the auxiliary rib-like wall 48.

As shown in FIG. 2 and FIG. 1, the grid electrode 24 and the auxiliary grid electrode 26
The grid wiring 28 and the auxiliary grid wiring 30 formed on the insulator layer 40 by thick-film printing, and the grid pad 50 and the auxiliary grid pad 52 formed continuously with the grid wiring 28 and the auxiliary grid wiring 52 respectively. Terminal 18 _G is connected to auxiliary grid terminal 18 _SG . These grid wiring 28, auxiliary grid wiring 30, grid pad 50, and auxiliary grid pad 52
In each case, the grid electrode 24 and the auxiliary grid electrode 26 are formed by thick film screen printing at the same time as the print formation. Therefore, these wirings 28, 3
0, pads 50 and 52 are also formed at the same height at the same time as the rib-like wall 46 and the auxiliary rib-like wall 48.
8 and the like are provided on an insulator film having the same shape.

Returning to FIG. 1, at the left end of the fluorescent display tube 10 in the drawing, that is, at one end in the longitudinal direction, an exhaust pipe 54 made of cylindrical glass is provided. This exhaust pipe 54 is used in the manufacturing process of the fluorescent display tube 10.
Substrate 12, spacer 14, and cover glass plate 16
After being sealed with glass to form an airtight container, it is provided for the purpose of evacuating and vacuuming from the inside thereof,
The tip is blown off by a gas burner or the like after the end of evacuation.

FIG. 4 is a diagram for explaining a connection relationship between the anode printed wiring 36 and the graphite layer 42 in the fluorescent display tube 10, that is, a wiring configuration for controlling light emission of each of the plurality of phosphor layers 22. FIG. In the figure, G
1, G2, G3, and G4 represent control units of the grid electrode 24, that is, divisions of columns to which a control voltage is simultaneously applied. The plurality of grid electrodes 24 provided so as to surround the phosphor layer 22 in each control unit G are connected to a common grid wiring 28 for each control unit G. In this figure, since the pattern is simplified for convenience of explanation, the shape and arrangement of each segment are shown in FIGS.
Is different from that shown in the upper row.
The phosphor layer 22 _S pattern of said shaped, large rectangular pattern of the shown in the lower left phosphor layer 2
2 _R respectively. That is, in FIGS. 1 and 2 described above, the slightly smaller “8” character-shaped phosphor layer 22 _{S in} which the grid electrodes 24 are connected to each other by being connected to the common grid wiring 28 as described above, of the phosphor layer 22 _R, they are both belonging to the control unit G1.

Each of the above control units G includes
Phosphor layer 22 representing a figure-eight shape in seven segments_SAnd compare
Phosphor area 22 having a relatively large area_ROr a long (line
State) phosphor layer 22_LAre provided respectively. These duplicates
Several phosphor layers 22 are selectively provided in each control unit G.
For each unit that emits light, for example, one by one, a graphite layer
A plurality of anode marks mutually independent of each other via 42
It is connected to one of the printed wirings 36. Printed wiring for anode
36 is a line unit so as to be common to each control unit G.
It is provided. In the figure, for example, ten positive
The pole printed wirings 36a to 36x are provided.
One to four phosphor layers 22 are connected to each of them. You
That is, a firefly that forms an eight-character shape by seven segments
Light body layer 22 _SAre mutually connected in the control units G1 to G4.
Printed wiring for anodes 36a-3 common to corresponding positions
6i, a linear phosphor layer 22_LEach of
Is the position corresponding to each other in the control units G2 to G4
Are connected to the common anode printed wirings 36h and 36i.
You. On the other hand, the rectangular phosphor layer 22_RIs for the anode
It is connected independently to the printed wiring 36x, and other phosphor layers
22 is electrically insulated. This embodiment
In the above, the anode printed wiring 36x becomes the first anode wiring,
The other anode printed wirings 36a to 36i are connected to the second anode wiring.
And the control unit G1 corresponds to one control unit.
You.

The plurality of grid wirings 28
The anode printed wiring 36 is connected to a drive driver in a control device (not shown), and a control voltage or a drive voltage is applied to the grid electrode 24, the graphite layer 42, or the like in accordance with an instruction from an arithmetic unit or the like in the control device. Will be applied.

FIG. 5 is a driving waveform diagram showing applied voltages used in an example of the control method. In the figure, G1
G4 to G4 are the voltages applied to the control units G1 to G4 of the grid electrode 24, and a to x are the anode printed wirings 36a to 36x.
Represents the applied voltage. Time t ₁ to t ₂ , t ₃ to
In each of the periods t ₄ , t _{5 to} t ₆ , and t _{7 to} t ₈ , a positive acceleration voltage is sequentially applied to the control units G1, G2, G3, and G4, and the application timing of the acceleration voltage is controlled. Synchronously, a positive drive voltage is applied to the anode printed wiring 36 corresponding to the phosphor layer 22 to emit light in each control unit. Each of the applied voltage waveforms a to x in FIG. 5 means that an on operation or an off operation is performed according to the presence or absence of a data signal during the period (that is, whether light emission or no light emission). One scan is t ₁
Ends with a period of ~t _9, the scanning time t ₉ after the same grid electrode 24 and it synchronized with anode printed wiring 36
The input of the data signal to is repeated.

In the above driving method, the anode printed wiring 36 is common to the plurality of phosphor layers 22 belonging to different control units, and therefore, the phosphor layer 22 _{S in} one control unit (for example, G1) is used. When a positive voltage is applied to other control units (for example, G2, G3,
In the phosphor layer 22 _S in G4) a positive voltage is applied. Therefore, in order to prevent the leakage light emission of the phosphor layer 22 _S, at the time of off-operation of the grid electrode 24 negative control voltage, that the cut-off bias is applied. At this time,
As described above, since the grid electrode 24 is provided only around the phosphor layer 22, the electric field strength decreases toward the inner peripheral side, and thus the grid electrode 24 has a large pattern like the phosphor layer 22 _R. Even if a cutoff bias is applied, leakage light emission may occur.

However, in the above-described driving waveform of the present embodiment, the control units G1 to G1
Whereas positive drive voltage during the acceleration voltage applied to any of the G4 may be applied, the anode wire 36x i.e. positive drive voltage only when the acceleration voltage applied to the control unit G1 in the phosphor layer 22 _R Is applied, and the driving voltage is not applied when the acceleration voltage is applied to the control units G2 to G4. In other words, only in the period for emitting the same positive voltage is applied to the phosphor layer 22 _R. Therefore, as described above, in the fluorescent display tube 10 which is dynamically driven as described above, since the phosphor layer _22R is statically driven, the formation of the grid electrode 24 is insufficient to the extent that the inner peripheral portion becomes insufficient. Phosphor layer 2 even if the intensity of the negative electric field
2 Leakage emission of _R can not occur.

In short, in this embodiment, only the phosphor layer 22 _R (that is, the graphite layer 42 provided below) in the control unit G1 is connected to the anode printed wiring 36x, while the anode printed wiring 36x is connected to the anode printed wiring 36x. A plurality of anode printed wirings 36a-3 independent of the printed wiring 36x and mutually independent
A plurality of phosphor layers 22 _S or 22 _L having different control units G are connected to 6i. for that reason,
Since the fluorescent display tube 10 is driven by a dynamic drive, the phosphor layer 22 _R is that are electrically independent from other phosphor layers 22 _S, 22 _L connected to the anode printed wiring 36a~36i The drive voltage can be applied only during the period (t _{1 to} t ₂ , t _{9 to} t _10, etc.) during which the phosphor layer 22 _R should emit light, regardless of the light emission timing of the phosphor layers 22 _S and 22 _L. . That is, the phosphor layer 22 _R is substantially driven by static driving a positive voltage is applied to the anode for printed wiring 36x for a period control unit G1 is selected and driven by static driving on the display surface 20 The display pattern (phosphor layer 22 _R ) is provided in combination with the display pattern (phosphor layers 22 _S , 22 _L ) driven by dynamic driving. Accordingly, even in a large pattern width dimension, such as the phosphor layer 22 _R become difficult leakage light emission control by the cutoff bias provided by adding a grid electrode as to change its design to the pattern in the Without this, it is possible to preferably suppress leakage light emission.

Although the present invention has been described in detail with reference to the drawings, the present invention can be embodied in other forms.

For example, in the embodiment, the control unit G1
One of the phosphor layers 22 _R has an independent anode printed wiring 3
6x has been described, but the phosphor layer 22 connected to the independent anode printed wiring 36 is
A plurality of control units may be provided. In this case, the plurality of phosphor layers 22 need to be connected to mutually different anode printed wirings 36. However, if there is a phosphor layer 22 that emits light simultaneously at the same time, they are connected to a common anode printed wiring. It can be connected to the wiring 36. That is, the "predetermined anode in one control unit" referred to in the claims.
May be plural, and the first anode wiring may be plural.

Although the control unit G1 can be constituted by a plurality of grid electrodes 24, the plurality of grid electrodes 24 do not necessarily have to be provided on the display surface 20 in close proximity to each other. Grid wiring 28
Is connected to a common wiring on the display surface 20 or outside the display tube 10 so as to be driven by one drive driver. I do.

Further, in the embodiment, even separate anode printed wiring 36x connected to the phosphor layers 22 _R, although the grid electrode 24 at positions surrounding the has been provided, the phosphor layer 22 _R is Since the static driving is performed, the positional relationship with the other phosphor layer 22 and the filament-shaped cathode 34
If the leakage light emission cannot occur and the light emission period cannot be reduced in relation to the intensity of the heat current applied to the heater, the grid electrode 24 is not provided and the electrode is partially formed into a diode structure. No problem.

In the embodiment, the phosphor layer 22 is provided on the display surface 20 of the substrate 12, but instead or in addition, the phosphor layer 22 is provided on the inner surface of the cover glass plate 16. The present invention is similarly applied to a transmissive fluorescent display tube of a type in which the light emission is observed through the cover glass plate 16 or a double-sided fluorescent display tube.

In the embodiment, the case where the present invention is applied to the fluorescent display tube 10 having only the character pattern has been described. However, both the character pattern and the dot matrix pattern are displayed on the display surface 20. Even when the character pattern is provided, the present invention can be similarly applied to the character pattern portion.

Although not specifically exemplified, the present invention
Various changes can be made without departing from the spirit of the invention.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view illustrating a structure of a fluorescent display tube according to an embodiment of the present invention.

FIG. 2 is a plan view showing a main part of a display surface of a substrate of the fluorescent display tube of FIG.

FIG. 3 is a diagram illustrating a substrate structure in a cross section taken along line aa and a cross section taken along line bb in FIG. 2;

FIG. 4 is a diagram illustrating a main part of a wiring connection configuration of the fluorescent display tube of FIG. 1;

FIG. 5 is a driving waveform diagram illustrating an example of a driving method in the wiring connection configuration of FIG. 4;

[Explanation of symbols]

10: fluorescent display tube 12: substrate 20: display surface 22: phosphor layer 24: grid electrode (control electrode) 34: filament 36: printed wiring for anode (36a to 36i: second anode wiring,
36x: first anode wiring) 42: graphite layer (anode) 46: rib-shaped wall G: control unit (G1: one control unit)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Jun Mouri 2160, Yatsu-cho, Yasu-cho, Asakura-gun, Fukuoka No. 2160 Noritake Electronics Industry Co., Ltd. Yasu Plant F-term (reference) 5C036 EE04 EE07 EF02 EF05 EG28 EG29 EG48 EH04 EH26 5C080 AA08 BB02 BB04 DD03 FF10 JJ06

Claims (3)

[Claims] 1. A plurality of anodes each having a phosphor layer provided on a surface thereof in a predetermined display pattern, a rib-like wall protruding around each of the plurality of phosphor layers, and a rib-like wall. A plurality of control electrodes provided for each predetermined control unit on the top of the wall are provided on the display surface of the substrate, and the control unit controls electrons generated from a cathode provided above the phosphor layer in a vacuum space. A fluorescent display tube of a type in which the phosphor layer emits light by controlling with an electrode, wherein a first anode wiring to which only a predetermined anode in one control unit of the plurality of anodes is connected; A plurality of anodes each having a different unit are connected to each other, and the plurality of anodes are electrically independent of the first anode wiring and a plurality of second anode wirings independent of each other are included. tube. 2. The fluorescent display tube according to claim 1, wherein said predetermined anode is provided in a shape sufficiently wide with respect to a control ability of said control electrode. 3. A positive control voltage is applied to the plurality of control electrodes for each control unit by sequentially selecting and scanning the control unit, and the first anode wiring and the first anode wiring are synchronized with the scanning. The method for driving the fluorescent display tube according to claim 1, wherein a positive drive voltage is applied to the plurality of second anode lines, wherein the one control unit is selected only during a selected period. A method for driving a fluorescent display tube, wherein a positive drive voltage is applied to a first anode wiring.