TW201712720A - Producing method of fluorescent display tube and fluorescent display tube - Google Patents

Abstract

An objective of this invention is to realize a fluorescent display tube at low cost. The fluorescent display tube of this invention has improved display quality by both suppressing the character missing and narrowed gap between anodes. This invention provides a method for producing a fluorescent display tube having an anode with anode electrode and a fluorescent material, and a filament for emitting electrons for illuminating the fluorescent material, which contains an electrode forming step of exposing and patterning a conductive photosensitive layer formed by coating a printing paste containing conductive material from powders of any one of ZnO, ITO or SnO2, and photosensitive agent, for forming the anode electrode and a surrounding electrode.

Description

Fluorescent display tube manufacturing method, fluorescent display tube

The present invention relates to a fluorescent display tube having an anode having an anode electrode and a phosphor, and a filament emitting electrons for causing the phosphor to emit light, and a method of manufacturing the same.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 11-339699

[Patent Document 2] Japanese Laid-Open Patent Publication No. 2009-272260

As a display device for displaying various kinds of information, a display device using a VFD (Vacuum Fluorescent Display) is known. The fluorescent display tube is provided with at least a filament (directly-heated cathode) and an anode in a vacuum vessel, and a direct current or an alternating current or a pulse voltage is applied to the filament to heat it to emit hot electrons, so that the hot electrons are formed The phosphor of the anode collides and illuminates to display the desired pattern.

As a display device including a fluorescent display tube, for example, it is used as a head-up display for a vehicle (Head-Up Display, the following mark) "HUD", but in the case of HUD, the user does not directly visually display the pattern of the light-emitting surface (display surface) of the fluorescent display tube, but enlarges the pattern emitted from the light-emitting surface onto the front glass or Since the object such as the integrator is visually observed, it is required to narrow the arrangement interval (the gap between the anodes) of the anode (phosphor) as much as possible in consideration of the presentation of the display pattern actually viewed by the user.

However, if the gap between the anodes is narrowed, the brightness of the outer edge of the fluorescent body of the anode is likely to be reduced, that is, "missing". This is because the potential of the insulator disposed between the anodes (between the anode electrodes) is set to the ground potential, so that the amount of electrons from the filament reaching the outer edge of the phosphor and the center of the phosphor due to the so-called electronic vignetting angle There are fewer reasons for the department.

In order to suppress the missing word, an electrode (surrounding electrode) as a planar gate is provided between the anodes, and it is effective to control the electric field around the phosphor by driving the peripheral electrodes. For example, Patent Document 1 discloses a fluorescent display tube provided with a planar grid.

Further, in addition to the above-described Patent Document 1, the above-mentioned Patent Document 2 can be further cited. Patent Document 2 discloses a technique of forming an anode wiring by a photolithography method.

Here, the fluorescent display tube can be manufactured by patterning a glass substrate and laminating a wiring layer, an insulating layer, an electrode layer, and a phosphor. At this time, the electrode layer and the insulating layer are laminated, and the manufacturing is reduced. From the standpoint of cost, it is desirable to use print formation (for example, pattern printing).

However, when formed by printing, it is difficult to form a narrow gap between the anodes, as compared with, for example, a film formation by a so-called sputtering method or a vacuum deposition method. In particular, when the above-described peripheral electrode is formed between the anodes in order to suppress the missing word, the gap between the anodes has to be increased, and the display quality is deteriorated from the viewpoint of the fine feeling of the display pattern.

Accordingly, an object of the present invention is to overcome the above-mentioned problems and to realize a fluorescent display tube which improves display quality by both the suppression of missing characters and the narrow gap between anodes at a lower cost.

A method for producing a fluorescent display tube according to the present invention is a method for producing a fluorescent display tube having an anode and a filament for emitting electrons for emitting the phosphor, wherein the anode has an anode electrode and a phosphor; The method has an electrode forming step of performing exposure patterning on a conductive photosensitive layer formed by applying a conductive paste containing a powder of a powder derived from any one of ZnO, ITO or SnO ₂ and a photosensitive paste to form the anode electrode. And the surrounding electrode of the foregoing anode electrode.

The anode electrode and its surrounding electrodes are formed by the above-described exposure patterning of the conductive photosensitive layer, and the fluorescent display tube is provided with a peripheral electrode to suppress the missing word, and even if the layer to be the electrode is laminated by printing, It is also possible to make the gap between the anodes fine. Further, ZnO, ITO, and SnO ₂ have a high transmittance for ultraviolet rays used for exposure, and are hard to hinder the hardening action by exposure. Therefore, this point also contributes to miniaturization of the gap between the anodes.

In the method for producing a fluorescent display tube according to the above aspect of the invention, the content of the conductive material in the printing paste is desirably 40% by weight to 60% by weight.

By appropriately setting the content ratio of the conductive material, it is possible to form a film to be an electrode while ensuring the film formation accuracy.

In the method for producing a fluorescent display tube according to the above aspect of the invention, the conductive material preferably has a powder average particle diameter of from 1 μm to 10 μm.

By appropriately setting the particle diameter of the conductive material, both good printability and patterning properties can be achieved.

In the above method for producing a fluorescent display tube of the present invention, the photosensitive agent is preferably contained in an amount of 5 wt% to 10 wt% of a photosensitive resin.

By appropriately setting the content ratio of the photosensitive resin in the photosensitive agent, both good printability and patterning properties can be achieved.

In the above method for producing a fluorescent display tube of the present invention, the conductive photosensitive layer is preferably formed to have a film thickness of 5 μm to 15 μm.

By appropriately setting the film thickness of the conductive photosensitive layer, it is possible to achieve both good characteristics as an electrode and good patterning properties.

Further, the fluorescent display tube of the present invention has: an anode having an anode electrode and a phosphor; and a filament emitting electrons for causing the phosphor to emit light, wherein the anode electrode is formed with a peripheral electrode, and the anode The electrode and the peripheral electrode include a powder of any one of ZnO, ITO, or SnO ₂ as a conductive material.

The above-mentioned ZnO, ITO, and SnO ₂ have a high transmittance for ultraviolet light used for exposure, and are hard to hinder the curing action by exposure. Therefore, the layer to be an electrode is laminated by printing, and the layer is exposed by exposure. When the anode electrode and the peripheral electrode are patterned, the gap between the anodes can be made fine.

According to the present invention, it is possible to realize a fluorescent display tube which improves the display quality in both of the suppression of the missing word and the narrow gap between the anodes at a lower cost.

1‧‧‧Fluorescent display tube

1a‧‧‧Display Department

1b‧‧‧Terminal Department

1c‧‧‧ drive

2‧‧‧glass containers

2a‧‧‧glass substrate

3‧‧‧Anode

4‧‧‧filament

5‧‧‧Anode wiring

6‧‧‧ surrounding electrodes

6a‧‧‧Photoetching electrode

6b‧‧‧through electrode

7‧‧‧Circumference wiring

8‧‧‧First insulation

9‧‧‧Second insulation

10‧‧‧ display device

11‧‧‧CPU

12‧‧‧Power circuit

12a‧‧‧Drive voltage generation circuit

12b‧‧‧Circumference electrode voltage generating circuit

12c‧‧‧ filament voltage generating circuit

31‧‧‧Fluorite

32, 32'‧‧‧Anode electrode

32a‧‧‧Photo Etching Electrode

32a’‧‧‧Printed electrodes

32b, 32b'‧‧‧through electrodes

BK‧‧‧ blank signal

CLK‧‧‧ clock signal

Ef‧‧‧ filament voltage

G‧‧‧ gap

Ha1 to Han‧‧‧ wiring

LAT‧‧‧Latch signal

Pp‧‧‧conductive paste

sF1‧‧‧ first signal

sF2‧‧‧second signal

SI‧‧‧ data signal

tBK‧‧‧Blank signal input terminal

tF1‧‧‧First filament terminal

tF2‧‧‧second filament terminal

tVd‧‧‧Drive voltage terminal

TVd‧‧‧Drive voltage terminal

tVin‧‧‧Power input terminal

tVs‧‧‧ peripheral electrode terminal

TVs‧‧‧ surrounding electrode terminals

Vin‧‧‧Power supply voltage

TF1‧‧‧First filament terminal

TF2‧‧‧second filament terminal

Fig. 1 is a schematic cross-sectional structural view showing a fluorescent display tube of an embodiment.

Fig. 2 is a schematic plan view showing a display unit having a fluorescent display tube in an embodiment.

Figure 3 is an explanatory diagram of the main cause of missing characters.

Fig. 4 is an explanatory diagram for the effect of suppressing the word deficiency from the surrounding electrodes.

Fig. 5 is an explanatory view showing a method of manufacturing a fluorescent display tube according to an embodiment.

Fig. 6 is also an explanatory view of a method of manufacturing a fluorescent display tube according to an embodiment.

Fig. 7 is a view showing the results of patterning of electrodes using the printing paste from Composition Example 1.

Fig. 8 is a view showing the results of patterning of electrodes using the printing paste from Composition Example 2.

Fig. 9 is a view showing the result of patterning the electrode using the printing paste from the composition example 3.

Fig. 10 is a block diagram showing a circuit configuration of a display device including a fluorescent display tube in an embodiment.

Hereinafter, embodiments of the present invention will be described.

Further, the description will be made in the following order.

<1. Fluorescent display tube construction >

<2. Manufacturing method>

<3. Composition of display device >

<4. Implementation of the integration of the situation >

<5. Modifications>

<1. Fluorescent display tube construction >

1 and 2 are explanatory views of the structure of the fluorescent display tube 1 according to the embodiment of the present invention, wherein Fig. 1 shows a schematic cross-sectional structure of the fluorescent display tube 1, and Fig. 2 shows an example of formation on a fluorescent display. The diagram of the arrangement pattern of the anode 3 of the tube 1 shows a schematic plan view of the display unit 1a having the fluorescent display tube 1. Moreover, the first figure mainly shows the schematic cross-sectional structure of the display part 1a.

In the fluorescent display tube 1, as the so-called segment display type fluorescent display tube, the anode 3 is disposed in accordance with the shape and the number of the display patterns (the figures such as numerals and arrows) to be realized. For example, in the digital portion illustrated in FIG. 2, in order to be switchable by a so-called 7-segment display Any value is displayed, and 7 anodes 3 are arranged for each digit.

In the present embodiment, a fluorescent display tube that is applied to a head-up display (hereinafter referred to as "HUD") device for a vehicle is exemplified as the fluorescent display tube 1.

In the fluorescent display tube 1, a structure is vacuum-packed in the glass container 2, and the structure includes necessary wirings, electrodes, and the like for causing the anode 3 to emit light (refer to Fig. 1).

In the fluorescent display tube 1, an anode wiring 5 for supplying a driving voltage to the anode 3 is formed for each anode 3 on the glass substrate 2a constituting the bottom of the glass container 2. Each of the anodes 3 has a photoetching electrode 32a, a phosphor 31 formed on the photoetching electrode 32a, and a through electrode 32b bonded to the photoetching electrode 32a.

In each of the anodes 3, an electrode formed by the through electrode 32b and the photo-etched electrode 32a is indicated by the anode electrode 32.

The through electrode 32b of the corresponding anode 3 is bonded to each anode wiring 5, whereby a driving voltage can be applied to the photoetching electrode 32a via the anode wiring 5. That is, the phosphor 31 formed on the anode electrode 32 can be made to emit light.

Further, in the fluorescent display tube 1, an insulating layer is formed by the first insulating layer 8 and the second insulating layer 9. The first insulating layer 8 is formed in such a manner that a part thereof is in contact with the glass substrate 2a, and the second insulating layer 9 is formed in such a manner that a part thereof is in contact with the first insulating layer 8. The insulating layers formed by the first insulating layer 8 and the second insulating layer 9 are formed such that the anode wiring 5 and the anode electrode 32 of each anode 3 are electrically insulated from each other.

Moreover, in the fluorescent display tube 1, a surrounding anode is formed The surrounding electrode 6 around 3 and the peripheral electrode wiring 7 for supplying a voltage to be applied to the surrounding electrode 6. The peripheral electrode wiring 7 is formed on the glass substrate 2a, and the peripheral electrode 6 has a photo-etching electrode 6a and a through electrode 6b that bonds the photo-etching electrode 6a and the peripheral electrode wiring 7.

The peripheral electrode 6 and the peripheral electrode wiring 7 are formed such that the first insulating layer 8 and the second insulating layer 9 are electrically insulated from each other between the anode wiring 5 and the anode electrode 32.

In addition, in the first drawing, only one through electrode 6b that joins the peripheral electrode 6 and the peripheral electrode wiring 7 is shown, but the through electrode 6b may be provided in a plurality of places.

In addition, in the first drawing and the second drawing, the display unit 1a includes the glass substrate 2a, the anode 3 (including the anode electrode 32), the anode wiring 5, the peripheral electrode 6, the peripheral electrode wiring 7, and the first insulation described above. Layer 8, and portions of second insulating layer 9.

In the fluorescent display tube 1 of the present embodiment, by applying a voltage to the peripheral electrode 6 provided as described above, it is possible to suppress the missing word.

In this regard, the description will be made with reference to FIGS. 3 and 4.

Fig. 3A is a schematic cross-sectional structural view of a display portion of a conventional fluorescent display tube, and Fig. 3B is a potential distribution between the filament 4 and the anode 3 (dotted line in the figure) and an electron track (thick arrow in the figure) Schematic diagram.

As shown in FIG. 3A, in the conventional display portion, the anode electrode 32' of each anode 3 has a through electrode 32b' and a printed electrode 32a' formed, for example, by pattern printing, and the printed electrode 32a' is formed in the second. On the insulating layer 9, the through electrode 32b' is bonded around the second insulating layer 9 The printed electrode 32a' and the anode electrode 5 are covered. Further, a phosphor 31 is formed on the printed electrode 32a'.

According to such a conventional structure, since the second insulating layer 9 is formed around each anode 3, even if a voltage is applied to the anode 3 through the anode wiring 5, as shown in FIG. 3B, electrons from the filament 4 become difficult. The outer edge portion (the broken line portion in the drawing) of the phosphor 31 is reached. This is because the potential of the second insulating layer 9 around the phosphor 31 is set to the ground potential, and the amount of electrons from the filament 4 to the outer edge portion of the phosphor 31 is higher than that of the phosphor due to the so-called electronic vignetting angle. The central part of 31 is less.

As a result, the amount of light emitted from the outer edge portion of the phosphor 31, that is, the amount of light emitted from the outer edge portion of the display segment is insufficient, resulting in a so-called "missing word".

On the other hand, according to the fluorescent display tube 1 in which the surrounding electrode 6 is provided, as shown in FIG. 4, the potential at the peripheral portion of the phosphor 31 can be higher than that of the conventional one, so that the firefly is reached. The amount of electrons in the outer edge portion of the light body 31 is larger than that of the conventional one.

Therefore, it is possible to suppress the "missing word".

<2. Manufacturing method>

Here, as described above, in particular, in the fluorescent display tube 1 applied to the HUD, it is required that the arrangement interval of the anodes 3 (the gap between the anodes 3) be as narrow as possible.

The formation of the fine pattern is effective, for example, by patterning using a so-called film formation such as a sputtering method or a vacuum deposition method. However, it is less preferable because it contributes to an increase in manufacturing cost.

Thus, in the present embodiment, the electrode in the fluorescent display tube 1 The formation of a layer or an insulating layer can be applied by printing to reduce the manufacturing cost.

A method of manufacturing the fluorescent display tube 1 according to the embodiment will be described with reference to FIGS. 5 and 6.

In the manufacturing method of the embodiment, first, the wiring forming step shown in FIG. 5A is performed. In the wiring forming step, the anode wiring 5 of each anode 3 and the peripheral electrode wiring 7 for the peripheral electrode 6 are formed on the glass substrate 2a. In the present example, aluminum is used as the material of the anode wiring 5 and the peripheral electrode wiring 7, and the formation (patterning) is performed by, for example, a sputtering method or a photolithography method.

Next, the first insulating layer forming step shown in Fig. 5B is performed. In the first insulating layer forming step, the position of the through electrode 32b of the anode 3 and the through electrode 6b of the peripheral electrode 6 is formed, and the formation of the first insulating layer 8 on the glass substrate 2a is performed. The first insulating layer forming step is performed by pattern printing. In this example, glass is used as the material of the first insulating layer 8, and in the first insulating layer forming step, the glass paste is patterned and then cured by firing.

Next, through the through electrode forming step shown in FIG. 5C, the through electrode 32b is formed on the anode wiring 5, and the through electrode 6b is formed on the peripheral electrode wiring 7. For example, silver is used as the material of the through electrodes 32b and 6b, and the through electrodes 32b and 6b are formed by pattern printing the silver paste in the through electrode forming step.

Further, the second insulating layer forming step shown in FIG. 5D is formed such that the second insulating layer 9 and the through electrodes 32b and 6b are not in contact with each other. In the second insulating layer forming step, the paste-like portion 2 The material forming the insulating layer 9 is patterned. In the case of this example, the same glass as the first insulating layer 8 is used as the second insulating layer 9, and the glass paste is patterned in the second insulating layer forming step, and then cured by firing.

Next, the photo-etching electrode forming step shown in FIGS. 6A and 6B is performed.

In the photo-etching electrode forming step, for the structure formed by the step up to the second insulating layer forming step described above, first, as shown in FIG. 6A, the conductive paste pp is printed on the screen, for example, in a screen. One side (in total spread) is applied. The conductive paste pp is a paste for printing containing a conductive material and a sensitizer. In this example, ZnO (zinc oxide) powder is used for the conductive material, and PVA-SBQ (PVA: which is an ultraviolet curable resin is used for the sensitizer). Polyvinyl alcohol, SBQ: styryl pyridinium salt adduct), which is adjusted to a desired viscosity (suitable for printing viscosity) by a solvent to form a paste.

Then, in the photo-etching electrode forming step, the solvent of the applied conductive paste pp in the above-described manner is dried, and the photo-etching electrode 32a to be the anode electrode 32 and the peripheral electrode 6 should be formed by separation. The photo-etching electrode 6a is patterned by photolithography. Specifically, the conductive paste pp after drying is subjected to pattern exposure and development. In this case, since the ultraviolet curable resin is used, the exposure is performed only for the portion to be the photo-etched electrode 32a and the portion to be the photo-etched electrode 6a, in other words, the boundary portion between the photo-etched electrode 32a and the photo-etched electrode 6a is not. Exposure object). Further, development is performed, for example, by water development.

By performing such exposure/development, a gap G between the photo-etching electrode 32a and the photo-etching electrode 6a as shown in Fig. 6B is formed. That is, the electrodes as the photo-etching electrode 32a and the photo-etching electrode 6a are formed independently.

After forming the respective electrodes as described above, the phosphor 31 is formed on each of the photoetching electrodes 32a by the phosphor forming step shown in Fig. 6C. The phosphor 31 is formed, for example, by pattern printing.

Thereby, the display portion 1a is formed in the fluorescent display tube 1.

In the above-described embodiment, a conductive paste (conductive paste pp) containing a conductive material and a sensitizer is applied to form a conductive photosensitive layer, and the conductive photosensitive layer is subjected to exposure patterning to form an anode electrode 32 and a peripheral electrode 6.

Thereby, at the time of manufacturing the fluorescent display tube 1 provided with the peripheral electrode 6 of the anode 3, a relatively inexpensive printing formation can be employed, and the gap G between the anode electrode 32 and the peripheral electrode 6 and the peripheral electrode 6 can be miniaturized. Wide. In other words, when the fluorescent display tube 1 provided with the peripheral electrode 6 is manufactured, it is possible to reduce the cost due to printing formation and to achieve a narrow gap between the anodes 3.

Further, in the case of this example, the minimum value of the gap between the anodes 3 is set to about 30 μm to 40 μm.

In this example, ZnO is used as the conductive material of the conductive paste pp, and this point also contributes to the narrow gap between the anodes 3. ZnO has a high transmittance to ultraviolet rays, and it is difficult to hinder the hardening effect by exposure, so that the precision of patterning can be improved. By seeking to improve the precision of the pattern, The gap G between the anode electrode 32 and the peripheral electrode 6 and the width of the peripheral electrode 6 can be made finer, so that the gap between the anodes 3 is made narrower.

Further, the material having a high transmittance to ultraviolet rays is suitable for the material of the conductive paste pp, and examples thereof include ITO (indium oxide-tin) and SnO ₂ (tin oxide).

Among them, suitable conditions of the conductive material used for the conductive paste pp are that they do not emit light even when a voltage is applied, and have no adverse effect on the vacuum characteristics in the fluorescent display tube 1, and are not affected by ion diffusion. The phosphor 31 causes adverse effects (specifically, does not cause a decrease in luminance of the phosphor 31). Examples of the conductive material satisfying these conditions include, in addition to the above-described ZnO, ITO, and SnO ₂ , aluminum or the like.

Further, in the conductive paste pp, the content (content ratio) of the conductive material should be considered. When the content rate of the conductive material is too small, the characteristics as an electrode may not be satisfied. Conversely, when it is too much, the viscosity characteristics of the printing paste cannot be satisfied, resulting in a decrease in film formation precision (for example, uniformity of film pressure, etc.).

As a result of conducting experiments from these viewpoints, it is found that the content of the conductive material (in this example, ZnO powder) in the conductive paste pp is preferably 40% by weight to 60% by weight. More preferably 50% by weight.

Further, although it is a powder particle diameter of the conductive material, it is a factor of the characteristics of the right and left conductive paste pp. When the particle size of the powder is too large, it becomes difficult to ensure the viscosity of the paste suitable for printing, which deteriorates the printability; when it is too small, the adhesion to the substrate is deteriorated to deteriorate the patterning property. Moreover, it is presumed that the deterioration of the adhesion to the substrate is such that when the particle diameter is small, the specific surface area with the conductive material increases, and the amount of the photosensitive agent increases. The area fixed to the base side becomes excessively large.

As a result of carrying out the experiment from the above viewpoint, the average particle diameter of the powder of the conductive material is preferably from 1 μm to 10 μm, more preferably 2 μm.

Further, regarding the photosensitive agent used for the conductive paste pp, the content of the photosensitive resin (in the present example, PVA-SBQ) is a factor for the accuracy of the left and right patterning.

When the amount of the photosensitive resin in the photosensitive agent is too small, the curing effect by exposure may not be sufficiently obtained, and the patterning property may be deteriorated. When the amount of the photosensitive resin is too large, the photosensitive agent itself may become unstable and gelatinized. It becomes difficult to maintain the viscosity of the conductive paste pp suitable for printing.

As a result of the experiment, the content (content ratio) of the photosensitive resin in the photosensitive agent is preferably from 5 wt% to 10 wt%, more preferably 7 wt%.

Further, the film thickness of the conductive photosensitive layer formed by applying the conductive paste pp should also be considered. When the film thickness of the conductive photosensitive layer is too thick, the patterning property from photoetching is deteriorated. When it is too thin, the resistance is high, and the characteristics of the electrode are deteriorated.

As a result of conducting experiments from the viewpoints, the thickness of the conductive photosensitive layer is preferably from 5 μm to 15 μm, more preferably 10 μm.

The inventors of the present invention conducted experiments on the patterning accuracy of the conductive paste pp using the printing pastes prepared in the following [composition example 1] to [composition example 3].

[Composition Example 1]

‧ Conductive material A = (ZnO powder, average particle diameter = 2 μm)... 50% by weight

‧ sensitizer A = (PVA-SBQ: 7wt%, sugar: 8wt%, propylene glycol: 85wt%)... 30wt%

‧ solvent = propylene glycol... 20wt%

[Composition Example 2]

‧ Conductive material B = (ZnO powder, average particle diameter = 0.1 μm)... 40wt%

‧ sensitizer A = (PVA-SBQ: 7wt%, sugar: 8wt%, propylene glycol: 85wt%)... 30wt%

‧ solvent = propylene glycol... 30wt%

[Composition Example 3]

‧ Conductive material B = (ZnO powder, average particle diameter = 0.1 μm)... 40wt%

‧ sensitizer B = (PVA-SBQ: 4wt%, monomer: 4wt%, propylene glycol: 92wt%)... 30wt%

‧ solvent = propylene glycol... 30wt%

Further, in the experiment, the difference in the ratio of the solvent between the composition example 1 and the composition examples 2 and 3 was changed in order to prevent the difference in the viscosity of the paste due to the difference in the particle diameter of the conductive material.

7 , 8 , and 9 show the results of patterning the electrodes using the conductive paste pp from the above-described composition example 1, composition example 2, and composition example 3, respectively. In addition, the B picture in each figure is an enlarged view of the center part of the corresponding A picture.

From the results shown in the above-mentioned 7th to 9th, it was confirmed that the conductive paste pp of the composition example 1 having an average particle diameter of 2 μm was used (No. 7). In the case of using the conductive paste pp of the composition examples 2 and 3 having an average particle diameter of 0.1 μm (Fig. 8, Fig. 9), the patterning accuracy can be improved. This is a confirmation of the preferred value of the above average particle diameter.

In the case of the conductive paste pp of the composition example 3 in which the content of the photosensitive resin is 4% by weight (Fig. 9), a composition example in which the content of the resin is 7 wt% is used. In the case of the conductive paste pp of 1, 2 (Fig. 7, Fig. 8), the improvement of the patterning accuracy was confirmed. This is a confirmation of the preferable conditions (5 wt% to 10 wt%) of the content of the photosensitive resin in the above sensitizer.

Further, as a difference between the photosensitizers A and B, in addition to the content ratio of the photosensitive resin, there are also differences in sugars/monomers. Although it cannot be said that the difference in the saccharide/monomer does not affect the patterning accuracy at all, the cause of the difference in patterning accuracy due to the sensitizers A and B is the difference in the content ratio of the photosensitive resin. Leading.

<3. Composition of display device >

Fig. 10 is a block diagram showing the circuit configuration of the display device 10 including the fluorescent display tube 1.

In the tenth diagram, the display device 10 includes a fluorescent display tube 1, and includes a CPU (Central Processing Unit) 11 and a power supply circuit 12.

The CPU 11 is data (display data) generated by whether or not the arbitrary anode 3 is lit (lighted) in the display unit 1a based on data and commands input from the outside (in this example, the vehicle end), in order to realize the display based on the display. The data makes the anode 3 light work, and generates various signals that should be given to the fluorescent display tube 1. number. Specifically, in order to generate the data signal SI, the clock CLK, the signal LAT is latched.

Moreover, the CPU 11 generates a blank signal BK for dimming control corresponding to an instruction from the outside. The blank signal BK is, for example, a PWM (Pulse Width Modulation) signal having a period of about 5 msec, and specifically, a signal for controlling the period during which the anode 3 is turned off. For example, the H level (on) indicates that the anode 10 is turned off, and the L level (off) indicates the lighting of the anode 10. The CPU 11 adjusts the on-duty of the blank signal BK corresponding to the ratio (%) of the blur indicated from the outside, that is, the operation (proportion) of the anode 3 during the light-off period. Specifically, when the blur ratio is large (the brightness of the anode 3 becomes smaller), the operation of the blank signal BK becomes large, and when the blur ratio becomes small (the brightness of the anode 3 becomes large), the operation of the blank signal BK becomes small.

The blank signal BK, the data signal SI, the clock signal CLK, and the latch signal LAT are supplied to the terminal portion 1b of the fluorescent display tube 1.

Moreover, in the case of this example, the blank signal BK is also supplied to the power supply circuit 12.

The fluorescent display tube 1 includes the above-described display unit 1a and the filament 4, and includes a terminal portion 1b and a driver 1c. Further, the fluorescent display tube 1 is provided with a driving voltage terminal TVd for inputting the operating voltage of the driver 1c, and a first filament terminal TF1 and a second filament for inputting the driving voltage of the filament 4 (hereinafter referred to as "filament voltage Ef"). The terminal TF2 and the peripheral electrode terminal TVs for inputting the peripheral electrode voltage to be applied to the peripheral electrode 6 in the display portion 1a.

The driver 1c inputs the data signal SI, the clock signal CLK, the latch signal LAT, and the blank signal BK generated from the CPU 11 through the terminal portion 1b, and can be transmitted through the wirings Ha1, Ha2, ..., Han respectively. One of the plurality of anode wirings 5 (n anode wirings 5) in the display portion 1a is associated with each of the connected wirings Ha, and a driving voltage is individually applied to each of the anodes 3 (in this example, a section).

The driver 1c reads the data signal SI from the serial data according to the clock signal CLK and the latch signal LAT and performs serial/parallel conversion. The opening/closing of the voltage applied to each anode 3 by the transmission wirings Ha1 to Han is performed based on the data (the binary data indicating the lighting/lighting) of each of the anodes 3 obtained by such serial/parallel conversion. (ON/OFF) control.

Thereby, the anode 3 of the display unit 1a is turned on by the pattern of the display data generated by the CPU 11.

Further, the driver 1c performs on/off control of applying a voltage to each anode 3 through the wirings Ha1 to Han based on the blank signal BK. Specifically, the on/off control of applying a voltage to each anode 3 is performed in accordance with the inverted signal of the blank signal BK.

Thereby, the blurring brightness adjustment described above is achieved.

Further, in the present example, the driving voltage (anode voltage) of the anode 3 is, for example, a DC voltage of 5.0 V.

The display unit 1a is connected to the input terminal TVs to the peripheral electrode wiring 7 shown in the previous FIG. Thereby, the surrounding electrode voltage can be applied to the surrounding electrode 6.

Filament 4 is intended to be discharged to form a shape at each anode 3 The emitted phosphor 31 emits electrons, and is driven by an AC drive signal (a first signal sF1 and a second signal sF2, which will be described later) generated and outputted by the power supply circuit 12, by applying an AC voltage as the filament voltage Ef.

The filaments 4 as shown are connected to the first filament terminal TF1 at one end and to the second filament terminal TF2 at the other end.

In the case of this example, the filament voltage Ef is set to an AC voltage of about 1 V effective value, and the average voltage value with respect to the ground (0 V) level is, for example, about -35 V.

The power supply circuit 12 includes, for example, a power supply input terminal tVin for inputting a power supply voltage Vin as a supply source of the vehicle battery, and a drive voltage terminal TVd, a peripheral electrode terminal TVs, and a first filament terminal TF1 in the fluorescent display tube 1. The driving voltage terminal tVd connected to the two filament terminals TF2, the peripheral electrode terminal tVs, the first filament terminal tF1, the second filament terminal tF2, and the blank signal input terminal tBK via the input blank signal BK, and the driving voltage generating circuit 12a and the surrounding electrode The voltage generating circuit 12b and the filament voltage generating circuit 12c.

The driving voltage generating circuit 12a generates an operating voltage of the driver 1c based on the power source voltage Vin, and outputs it through the driving voltage terminal tVd.

Further, the filament voltage generating circuit 12c generates a first signal sF1 and a second signal sF2 for driving the filament 4 based on the power source voltage Vin, and outputs the first signal terminal tF1 and the second filament terminal tF2 through the first filament terminal tF1 and the second filament terminal tF2. The first signal sF1 is a pulse signal set to be repeatedly turned on/off at a predetermined period, and the second signal sF2 is an inverted signal set as the first signal sF2. Again, the first signal in this example The peak voltage value (voltage value during the turn-on period) of sF1 and second signal sF2 is set to about 1V.

The ambient electrode voltage generating circuit 12b generates a peripheral electrode voltage for driving the peripheral electrode wiring 7 based on the power source voltage Vin, and outputs it through the peripheral electrode terminal tVs.

At this time, the ambient electrode voltage of the peripheral electrode voltage generating circuit 12b is turned on/off in synchronization with the blank signal BK. Specifically, in this example, the peripheral electrode voltage is turned on/off in synchronization with the inverted signal of the blank signal BK.

In this way, since the voltage is applied to the peripheral electrode 6 only in the opening period of the anode 3 accompanying the blur, the power consumption in preventing the occurrence of the missing word can be minimized, and the power consumption can be reduced.

Moreover, the ambient electrode voltage does not have to be turned on/off in synchronization with the blank signal BK.

<4. Implementation of the integration of the situation >

A method of manufacturing a fluorescent display tube according to the above embodiment is characterized in that an anode (the same 3) having an anode electrode (same as 32) and a phosphor (same 31) is produced, and a phosphor is emitted to emit light. A method for producing a fluorescent display tube of the same (fourth), wherein the method has an electrode forming step of applying a conductive material containing a powder derived from any one of ZnO, ITO or SnO ₂ The conductive photosensitive layer formed of the photosensitive paste (conductive paste pp) is subjected to exposure patterning to form a peripheral electrode of the anode electrode and the anode electrode (same as 6).

By patterning the exposure of the conductive photosensitive layer by the above-described method, the peripheral electrodes of the anode electrode and the anode electrode are formed, and the fluorescent display tube is provided with the peripheral electrode to suppress the missing word, and the layer to be the electrode is printed by printing. The layering can also make the gap between the anodes fine. Further, ZnO, ITO, and SnO ₂ have a high transmittance for ultraviolet rays used for exposure, and are hard to hinder the hardening action by exposure. Therefore, this point also contributes to miniaturization of the gap between the anodes.

Therefore, it is possible to realize a fluorescent display tube in which the display quality is improved by both the suppression of the missing word and the narrow gap between the anodes at a lower cost.

According to the manufacturing method of the foregoing embodiment, the gap G between the photo-etched electrode 32a (anode electrode 32) and the photo-etched electrode 6a (surrounding electrode 6) can be narrowed, by such an anode electrode 32 and surrounding The narrow gap between the electrodes 6 reduces the voltage value of the surrounding electrode voltage to be applied to suppress the missing word. In other words, according to the manufacturing method of the embodiment, it is possible to prevent the word shortage and reduce the power consumption.

Further, in the manufacturing method of the embodiment, the content of the conductive material in the printing paste is set to 40% by weight to 60% by weight.

By appropriately setting the content of the conductive material, it is possible to form a film to be an electrode while ensuring the film formation precision.

Further, in the production method of the embodiment, the powder has an average particle diameter of 1 μm to 10 μm.

By appropriately setting the particle diameter of the conductive material, both good printability and patterning properties can be achieved.

Further, in the manufacturing method of the embodiment, the photosensitive agent contains 5 wt% to 10 wt% of the photosensitive resin.

By appropriately setting the content ratio of the photosensitive resin in the photosensitive agent, both good printability and patterning properties can be achieved.

Further, in the manufacturing method of the embodiment, the conductive photosensitive layer is formed with a film thickness of 5 μm to 15 μm.

By appropriately setting the film thickness of the conductive photosensitive layer, it is possible to achieve both good characteristics as an electrode and good patterning properties.

Further, the fluorescent display tube (same as 1) of the embodiment has an anode (the same as 3) having an anode electrode (same as 32) and a phosphor (31), and an electron for emitting light for emitting the phosphor. In the filament, the anode electrode is formed with a peripheral electrode (same as 6), and the anode electrode and the peripheral electrode contain powder of any one of ZnO, ITO or SnO ₂ as a conductive material.

As described above, ZnO, ITO, and SnO ₂ have a high transmittance for ultraviolet light used for exposure, and it is difficult to hinder the hardening action by exposure. Therefore, layering of a layer to be an electrode is performed by printing and the layer is layered. When the exposure pattern is formed to form the anode electrode and the surrounding electrode, the gap between the anodes can be made fine.

Therefore, it is possible to realize a fluorescent display tube in which the display quality is improved by both the suppression of the missing word and the narrow gap between the anodes at a lower cost.

<5. Modifications>

The embodiment of the present invention has been described above, but the present invention is not limited to the specific examples described above, and various modifications can be made without departing from the scope of the invention.

For example, in the above, a fluorescent display tube of a type in which a segment pattern display is performed is exemplified, but the present invention is also suitable for a fluorescent display tube for performing dot matrix display, for example, an active matrix type fluorescent display tube.

Moreover, the present invention is also applicable to display devices other than HUDs for vehicles.

2a‧‧‧glass substrate

5‧‧‧Anode wiring

6‧‧‧ surrounding electrodes

6a‧‧‧Photoetching electrode

6b‧‧‧through electrode

7‧‧‧Circumference wiring

8‧‧‧First insulation

9‧‧‧Second insulation

31‧‧‧Fluorite

32‧‧‧Anode electrode

32a‧‧‧Photo Etching Electrode

32b‧‧‧through electrode

G‧‧‧ gap

Pp‧‧‧conductive paste

Claims (6)

A method of manufacturing a fluorescent display tube comprising: an anode having an anode electrode and a phosphor; and a filament emitting electrons for causing the phosphor to emit light, the method having an electrode forming step: coating The conductive photosensitive layer containing the conductive material of the powder of any one of ZnO, ITO or SnO ₂ and the photosensitive paste is subjected to exposure patterning to form the anode electrode and the peripheral electrode of the anode electrode. The method for producing a fluorescent display tube according to the first aspect of the invention, wherein the content of the conductive material in the printing paste is 40% by weight to 60% by weight. The method for producing a fluorescent display tube according to the above aspect of the invention, wherein the conductive material has a powder average particle diameter of from 1 μm to 10 μm. The method for producing a fluorescent display tube according to any one of claims 1 to 3, wherein the photosensitive agent contains 5 wt% to 10 wt% of a photosensitive resin. The method for producing a fluorescent display tube according to any one of claims 1 to 4, wherein the conductive photosensitive layer is formed to have a film thickness of 5 μm to 15 μm. A fluorescent display tube comprising: an anode having an anode electrode and a phosphor; and a filament emitting electrons for emitting the phosphor; the anode electrode is formed with a peripheral electrode, and the anode electrode and the peripheral electrode are A powder containing ZnO, ITO or SnO ₂ as a conductive material.