JPH09167568A - Gas discharge type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict short-circuit between electrodes, lowering of a voltage starting incorrect power discharge caused by migration phenomena generated by movable ion such as sodium ion in a glass board even during high- temperature operation in a gas discharge type display device. SOLUTION: By setting an sodium oxide content of a glass board constituting a front face plate and a back face plate of a gas discharge type display device to 2wt.% or more and 5.5wt.% or less, 2wt.% or more and 5wt.%, or 2wt.% or more and 4.2wt.%, the lowering of an erroneous discharge voltage can be restricted to 3V, 2V, or 1V or less, respectively, and even when content of sodium oxide is above these values and when is 30wt.% or less, migration phenomena is prevented by adding potassium oxide of the quantity corresponding to the inclusion ratio of that sodium oxide, and the lowering of the erroneous discharge voltage can be restricted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas discharge type display device.

[0002]

2. Description of the Related Art In recent years, a gas discharge type display device (plasma display panel, hereinafter referred to as PDP) has been used as a flat type display device for an information terminal such as a portable computer, and has a clear display and a liquid crystal panel. The field of application is expanding due to the wide viewing angle. In addition, television receivers have become larger, and in response, projection televisions using projection-type cathode ray tubes or liquid crystal panels have been commercialized, but in both cases, the brightness of the screen is increased and the device is enlarged. Remains a challenge.

On the other hand, PDPs have recently been remarkably advanced in colorization technology, and are now in the spotlight as display devices capable of greatly reducing the depth in place of cathode ray tubes. It is attracting attention as the rightmost wing, and is expected to have faithful color reproduction and improved brightness and life.

Next, an example of a memory drive type DC PDP will be described with reference to FIG. As shown in the figure, in a general DC type PDP, a group of cathode lines 2 formed on a transparent front plate 1 is orthogonal to a group of anode buses 4a formed on a back plate 3 and anodes 4b connected thereto. A plurality of discharge cells 6 are formed in a matrix at the intersections of the discharge cells 6 which face each other with the barrier ribs 5 sandwiched therebetween. The periphery of the combined front plate 1 and back plate 3 is sealed with a low melting point glass or the like, and a discharge gas mainly composed of a rare gas is sealed inside.

A display electrode body 7 is installed on an anode 4b on the back plate 3 side of each discharge cell 6, and the anode 4b is connected to an anode bus bar 4a by a resistor 8 and is connected to the display electrode body 7. A pair of discharge electrodes is constituted by the cathode line 2. The phosphor 9 is applied to the back plate 3 except for the display electrode body 7. In addition, cathode plate 2 on front plate 1
The other parts are transparent, and the phosphor 9 is passed through the discharge cell 6.
The surface of the can be observed directly.

A glass substrate generally used as the front plate 1 or the rear plate 3 of the PDP is disclosed in Japanese Patent Laid-Open No. 58-953.
As disclosed in Japanese Patent Publication No. 82-82, a movable ion blocking film is formed on the surface of soda glass or a glass substrate of this type containing sodium oxide in an amount of about 10 to 20% by weight, and a back plate is formed on the upper surface of the soda glass. In the case of 3, the anode bus bar 4a and the anode 4b are formed by a printing technique or a photolithography technique.
Alternatively, the resistor 8 or the like is formed.

[0007]

When a glass substrate having no movable ion blocking film formed on its surface is used in this gas discharge display device, when a voltage is applied to the PDP to display an image, the same substrate is used. There may be a case where the resistance is reduced or a short circuit occurs between the electrodes that are installed in the PDP, and prevention of these is strongly demanded in terms of extending the life of the PDP and improving the reliability. This phenomenon is because the sodium ions contained in the glass substrate are likely to move, so that when an image is displayed by applying a voltage to the PDP, the rear plate 3 in the portion where the anode bus bar 4a and the anode 4b are provided. It is considered to be due to a so-called migration phenomenon in which sodium ions inside gather at the ends of the anode bus bar 4, etc., react with the anode bus bar metal to generate a conductive intermetallic compound, and grow in a whisker shape.

Further, it is required to prevent erroneous discharge due to a decrease in discharge starting voltage, that is, to keep the decrease in voltage at which erroneous discharge starts (hereinafter referred to as erroneous discharge voltage) within a prescribed value. It is considered that this decrease in erroneous discharge voltage is due to the diffusion of sodium ions in the glass substrate into the cathode, thus lowering the work function of the cathode.

In order to meet these requirements, a method of forming a film between the glass substrate and the electrode wiring group for suppressing the generation and movement of sodium ions has been recently used. In general, as a blocking film for suppressing the generation and movement of sodium ions, a powder such as aluminosilicate glass that does not contain sodium is applied by a printing method and applied by baking, and the melting point of the glass is used. Since a small amount of lead component is contained for lowering the temperature, when the temperature of the panel becomes high, the lead ionizes and reacts with the electrode metal as in the case of sodium, which may cause a migration phenomenon due to the formation of an intermetallic compound. Therefore, regardless of the method of printing the glass paste, as disclosed in JP-A-58-95382, a SiO ₂ film, an S
There is a method of forming a blocking film such as an i ₃ O ₄ film or an Al ₂ O ₃ film, but in the case of a large display panel for a television receiver, the blocking film forming device becomes extremely huge and the manufacturing cost is naturally high. As the price rises, new issues arise. That is, unless the respective coefficients of thermal expansion of the glass substrate, the blocking film, and the electrode formed thereon are matched, the blocking film may be cracked in the electrode printing and firing process. Further, the non-uniformity of the film thickness of the blocking film and the reduction of the light transmittance due to the formation of the blocking film may greatly affect the display quality.

According to the present invention, even when the panel is operated at a high temperature without increasing the manufacturing cost of the PDP, a short circuit between electrodes due to a migration phenomenon caused by a mobile ion such as sodium ion existing in the glass substrate or an erroneous phenomenon occurs. An object of the present invention is to provide a highly reliable gas discharge display device capable of suppressing a decrease in discharge voltage and the like.

[0011]

In order to solve this problem, the present invention has a sodium oxide content ratio of 2% by weight or more and 5.5 in a glass substrate constituent material constituting a front plate and a back plate.
By reducing the weight to less than 3%, the erroneous discharge voltage is reduced by 3V.
By suppressing the short circuit between the electrodes and preventing the short circuit between the electrodes, and by controlling the sodium oxide content ratio to be 2 wt% or more and 5 wt% or less, the reduction of the erroneous discharge voltage is suppressed within 2 V, and the content ratio of sodium oxide is 2 wt% or more 4.2 wt%
By the following, it is possible to suppress the decrease of the erroneous discharge voltage to within 1 V and prevent the short circuit between the electrodes due to the migration phenomenon.

When the content ratio of sodium oxide becomes higher than the above, potassium oxide in an amount corresponding to that amount is added to define the appropriate ratio ranges of sodium oxide, potassium oxide and the remaining glass component. By doing so, it is possible to suppress the reduction of the erroneous discharge voltage within a predetermined range and prevent the short circuit between the electrodes due to the migration phenomenon.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is a front plate provided with a group of cathode lines, a group of anode buses and an anode connected to the anode buses through resistors, respectively. A back plate provided with an electrode body and a phosphor is opposed to each other by a partition wall and a rare gas is sealed therein, and the content ratio of sodium oxide in a glass substrate forming the front plate and the back plate is constant. The structure is limited to the following, or the amount of potassium oxide corresponding to the sodium oxide content ratio is added, and it is possible to suppress a decrease in erroneous discharge voltage and prevent a short circuit between electrodes due to a migration phenomenon. .

The invention according to claim 2 has the same structure as the gas discharge type display device according to claim 1, wherein the content ratio of sodium oxide in the glass substrate constituent material constituting the front plate and the back plate is The content is set to 2% by weight or more and 5.5% by weight or less, and it is possible to suppress a decrease in erroneous discharge voltage to 3 V or less and prevent short circuits between electrodes due to a migration phenomenon.

The invention according to claim 3 has the same structure as that of the gas discharge type display device according to claim 1, wherein the content ratio of sodium oxide in the glass substrate constituent material constituting the front plate and the back plate is The content is set to 2% by weight or more and 5% by weight or less, and it is possible to suppress a decrease in erroneous discharge voltage to 2 V or less and prevent a short circuit between electrodes due to a migration phenomenon.

The invention according to claim 4 has the same structure as that of the gas discharge display device according to claim 1, wherein the content ratio of sodium oxide in the glass substrate constituent material constituting the front plate and the back plate is The content is set to 2% by weight or more and 4.2% by weight or less, and it is possible to suppress a decrease in erroneous discharge voltage to 1 V or less and prevent a short circuit between electrodes due to a migration phenomenon.

The invention according to claim 5 has the same structure as that of the gas discharge display device according to claim 1, wherein the glass substrates constituting the front plate and the back plate are sodium oxide, potassium oxide and the remainder. In the weight percentage composition diagram of these three components, sodium oxide is X, potassium oxide is Y, and the remaining components are Z, and each composition point is (X, Y,
Z), point A (2, 38, 60), point B (2, 0, 9)
8), C point (5.5, 0, 94.5), D point (22, 18, 60), and the content ratio (% by weight) of the area excluding the line connecting B point and C point , Decrease of erroneous discharge voltage is 3
The voltage can be suppressed to V or less and a short circuit between electrodes due to a migration phenomenon can be prevented.

The invention according to claim 6 has the same structure as that of the gas discharge type display device according to claim 1, wherein the glass substrates constituting the front plate and the back plate are sodium oxide, potassium oxide, and the remainder. In the weight percentage composition diagram of these three components, sodium oxide is X, potassium oxide is Y, and the remaining components are Z, and each composition point is (X, Y,
Z), point A (2, 38, 60), point B (2, 0, 9)
8), surrounded by points C (5, 0, 95) and points D (21, 19, 60), and having the content ratio (% by weight) of the area excluding the line connecting points B and C. , Decrease in erroneous discharge voltage by 2
The voltage can be suppressed to V or less and a short circuit between electrodes due to a migration phenomenon can be prevented.

The invention according to claim 7 has the same structure as that of the gas discharge type display device according to claim 1, wherein the glass substrates constituting the front plate and the back plate are sodium oxide, potassium oxide and the remainder. In the weight percentage composition diagram of these three components, sodium oxide is X, potassium oxide is Y, and the remaining components are Z, and each composition point is (X, Y,
Z), point A (2, 38, 60), point B (2, 0, 9)
8), the point C (4.2, 0, 95.8), the point D (20, 20, 60), and the content ratio (% by weight) of the area excluding the line connecting the points B and C. , Decrease the false discharge voltage by 1
The voltage can be suppressed to V or less and a short circuit between electrodes due to a migration phenomenon can be prevented.

Embodiments of the present invention will be described below with reference to FIGS. 2 and 3 and Tables 1 and 2. Also PD
The structure of P is the same as that of the PDP shown in FIG. 1 except for the constituent materials of the glass substrates forming the front plate and the back plate,
Description is omitted.

The constituent materials of the glass substrate are shown in Table 1, but a composition containing silicon dioxide as a main component and an oxide other than potassium oxide and sodium oxide was used as the remaining components. In the glass substrate used in the present embodiment, each component was adjusted so that the total amount was 100% by weight within the composition range shown in Table 1.

[0022]

[Table 1]

The glass substrates shown in Table 1 are basically soda lime glass having a composition close to that of an aluminosilicate system, but Fe ₂ O ₃ and MnO are used as impurities due to the fact that a mineral raw material is mainly used for adjustment and melting. , Ti
_{O 2, As 2 O 3,} SnO 2 or the like may be mixed, but both can be used as a front plate or back plate for PDP if 0.5 wt% or less.

(Embodiment 1) FIG. 2 shows the relationship between the content ratio (wt%) of sodium oxide in the glass substrates used for the front and back plates of the PDP in Embodiment 1 of the present invention and the erroneous discharge voltage. Are studied under different operating temperature conditions. The glass substrate used in this embodiment is
Among the constituent materials shown in Table 1, potassium oxide is not included, but sodium oxide and the remaining components are used.

As shown in FIG. 2, when the operating temperature is room temperature,
If the content ratio of sodium oxide is 20% by weight or less, the erroneous discharge voltage does not change significantly, and the fluctuation range remains within 2 V, but when the operating temperature reaches 90 ° C, the content ratio of sodium oxide is 1%. If it exceeds 0.5% by weight, the erroneous discharge voltage starts to drop, and it is still within 3V up to 5.5% by weight, but if it exceeds 5.5% by weight, it falls outside the allowable range of erroneous discharge voltage drop (within 3V). Will result.

Therefore, in order to keep the drop of the erroneous discharge voltage within the allowable range of 3 V even at a relatively high temperature and to maintain a stable discharge, the content ratio of sodium oxide in the glass substrate is 5.5% by weight. It is necessary to keep it below%.

The content ratio of sodium oxide is 5% by weight.
If the following is set, the decrease in erroneous discharge voltage can be kept within 2 V, and if the content ratio of sodium oxide is set to 4.2% by weight or less, the decrease in erroneous discharge voltage can be kept within 1 V.

(Embodiment 2) Next, the case where potassium oxide is added to a glass material containing sodium oxide will be described. Table 2 is a table showing the constituent materials of the glass substrates forming the front plate and the rear plate used in the PDP of this embodiment.

[0029]

[Table 2]

In Table 2, the content ratio (weight percentage) a
Is the composition ratio (% by weight) when suppressing the decrease of the false discharge voltage within 3V, and the content ratio (weight percentage) b is the composition ratio (% by weight) when suppressing the decrease of the incorrect discharge voltage within 2V.
The content ratio (weight percentage) c is 1
The composition ratios (% by weight) in the case of being suppressed within V are shown respectively. The points indicated by A to D are points that define the respective appropriate ratio ranges in the weight percentage composition chart of the three components consisting of sodium oxide, potassium oxide and the remaining components.

First, the case where the reduction of the erroneous discharge voltage is kept within the allowable range of 3V will be described. FIG. 3 shows the content ratio a shown in Table 2 in the weight percentage composition diagram of the three components. In FIG. 3, points B and C and the line connecting them indicate the case where the content ratio of potassium oxide is 0% by weight, which corresponds to the first embodiment. Therefore, when potassium oxide is added, if the composition of the glass substrate is within the range surrounded by points except point B, point C and the line connecting them, the reduction of the erroneous discharge voltage is kept within 3V. be able to.

Similarly, in the case of the content ratio b and the content ratio c in Table 2, the content ratio of potassium oxide is 0% by weight on each of the points B and C and the line connecting them.
This corresponds to the first embodiment. Therefore, when potassium oxide is added, if the composition constituting the glass substrate is within the range surrounded by the points except point B, point C and the line connecting them, the erroneous discharge voltage lowers at the content ratio b. Within 2V, with the content ratio c, the decrease in erroneous discharge voltage can be limited within 1V.

FIG. 4 shows the content ratio and the erroneous discharge voltage when sodium oxide and potassium oxide are both contained in the glass substrates used for the front and back plates of the PDP in the present embodiment. Relation, operating temperature 9
This is an examination of the case of 0 ° C. As shown in the figure, even if the content ratio of sodium oxide is increased, it is possible to stably maintain the erroneous discharge voltage by adding the necessary amount of potassium oxide.

As shown in FIG. 4, if the content ratio of sodium oxide is about 10 to 15% by weight, which is the same as that in relatively inexpensive soda glass, about 4.5 to 6% by weight of potassium oxide is added. As a result, it is possible to prevent the release or movement of sodium ions from sodium oxide in the glass substrate. Therefore, it is possible to suppress a short circuit between electrodes and a reduction in erroneous discharge voltage due to metallization due to migration of sodium ions. The amount of potassium oxide added may be determined depending on how much the allowable range for reducing the erroneous discharge voltage is set.

As described above, according to the above embodiment, the PD
Potassium oxide is required by adjusting the amount of sodium oxide contained in the glass substrate constituting the front plate or the back plate of P to 5.5% by weight or less, or when sodium oxide is present in the range of 30% by weight or less. By adding a large amount, it is possible to prevent a short circuit between electrodes due to a migration phenomenon and a decrease in erroneous discharge voltage, thereby suppressing erroneous discharge.

As described above, there is a strong correlation between the decrease in erroneous discharge voltage and the content ratio of sodium oxide, and the content ratio of sodium oxide is reduced or potassium oxide corresponding to the content ratio of sodium oxide is changed. It is clear that the addition can prevent the reduction of the erroneous discharge voltage. However, if the content ratio of sodium oxide decreases, glass processing becomes difficult. That is, in the process of manufacturing a glass substrate for PDP, there are operations such as cutting, processing of a cut surface, and drilling. However, if the content ratio of sodium oxide is reduced, the glass is easily broken, and these processing become difficult. The boundary indicated by the line connecting points A and B in FIG. 3 is mainly determined by the point of workability. Further, with respect to the arbitrary content ratio of sodium oxide, the more the added amount of potassium oxide is, the more the decrease of the erroneous discharge voltage can be suppressed, but the sum of the content ratio of sodium oxide and the content ratio of potassium oxide is 40% by weight. If it exceeds%, it becomes difficult to form glass. The boundaries indicated by points A to D in FIG. 3 are mainly determined by whether or not the properties as glass can be maintained. The boundary indicated by the line connecting points C and D in FIG. 3 is
This is mainly determined by keeping the reduction of the erroneous discharge voltage within a certain range.

Therefore, the content ratio of each composition of the glass substrate consisting of sodium oxide, potassium oxide and the remaining components depends on the workability of the glass substrate, whether or not the properties as glass can be maintained, and how much the false discharge voltage is lowered. It may be determined within the range determined in Table 2 in consideration of the three points of allowance.

[0038]

As described above, according to the present invention, an electrode caused by a migration phenomenon caused by movable ions such as sodium ions in a glass substrate even when the panel is operated at high temperature without increasing the manufacturing cost of the PDP. It is possible to provide a highly reliable gas discharge type display device which can suppress a short circuit between them, a decrease in erroneous discharge voltage, and the like.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a general gas discharge display device.

FIG. 2 is a diagram showing a relationship between an erroneous discharge voltage and a sodium oxide content ratio in a glass substrate of a gas discharge display device according to an embodiment of the present invention.

FIG. 3 is a weight percentage composition diagram of three components, which are the constituent materials of the glass substrate, which are sodium oxide, potassium oxide, and the remaining components.

FIG. 4 is a diagram showing a relationship between a content ratio of sodium oxide and potassium oxide in a glass substrate of a gas discharge display device according to another embodiment of the present invention and an erroneous discharge voltage.

[Explanation of symbols]

 1 Front Plate (Glass Substrate) 2 Cathode Line 3 Back Plate (Glass Substrate) 4a Anode Bus 4b Anode 5 Partition 7 Display Electrode 8 Resistor 9 Phosphor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoichi Morikawa 1-1, Saiwaicho, Takatsuki City, Osaka Prefecture Matsushita Electronics Industrial Co., Ltd.

Claims (7)

[Claims] 1. A partition plate comprising a front plate having a group of cathode lines, a group of anode buses and an anode connected to each of the anode buses through a resistor, a back plate having a display electrode body and a phosphor. The glass substrates constituting the front plate and the back plate are limited to a certain amount or less, or the sodium oxide content ratio is maintained by facing each other by enclosing a rare gas therein. A gas discharge type display device characterized in that an amount of potassium oxide corresponding to is added. 2. A partition wall comprising a front plate having a group of cathode lines, a group of anode buses and an anode connected to the anode buses via resistors respectively, a display plate and a back plate having a phosphor. Are opposed to each other and sealed with a rare gas inside, and the content ratio of sodium oxide in the glass substrate constituent material forming the front plate and the rear plate is 2% by weight or more and 5.5% by weight or less. A gas discharge type display device characterized by the above. 3. A partition wall comprising a front plate having a group of cathode lines, a group of anode buses and an anode connected to each of the anode buses through a resistor, a rear plate having a display electrode body and a phosphor. And a rare gas is sealed inside, and the content ratio of sodium oxide in the glass substrate constituent material forming the front plate and the rear plate is 2% by weight or more and 5% by weight or less. Characteristic gas discharge type display device. 4. A partition wall comprising a front plate having a group of cathode lines, a group of anode buses and an anode connected to the anode buses via resistors respectively, a display plate and a back plate having a phosphor. Are opposed to each other and sealed with a rare gas inside, and the content ratio of sodium oxide in the glass substrate constituent material constituting the front plate and the rear plate is 2% by weight or more and 4.2% by weight or less. A gas discharge type display device characterized by the above. 5. A partition wall comprising a front plate having a group of cathode lines, a group of anode buses and an anode connected to the anode buses via resistors respectively, a display plate and a rear plate. The glass substrates constituting the front plate and the back plate are made of sodium oxide, potassium oxide and the remaining components, and are held facing each other by a rare gas. When the sodium oxide is X, the potassium oxide is Y, the remaining components are Z, and each composition point is represented by (X, Y, Z),
Point A (2, 38, 60), Point B (2, 0, 98), Point C (5.5, 0,)
94.5), content ratio of the area surrounded by points D (22, 18, 60) and excluding the line connecting points B and C (% by weight)
A gas discharge type display device having: 6. A partition wall comprising a front plate having a group of cathode lines, a group of anode buses and an anode connected to the anode buses via resistors respectively, a rear plate having a display electrode body and a phosphor. The glass substrates constituting the front plate and the back plate are made of sodium oxide, potassium oxide and the remaining components, and are held facing each other by a rare gas. When the sodium oxide is X, the potassium oxide is Y, the remaining components are Z, and each composition point is represented by (X, Y, Z),
Point A (2, 38, 60), Point B (2, 0, 98), Point C (5, 0, 9)
5) A gas discharge display device having a content ratio (wt%) of a region surrounded by points D (21, 19, 60) and excluding the line connecting the points B and C. 7. A partition plate comprising a front plate having a group of cathode lines, a group of anode buses and an anode connected to the anode buses via resistors respectively, a display plate and a back plate having a phosphor. The glass substrates constituting the front plate and the back plate are made of sodium oxide, potassium oxide and the remaining components, and are held facing each other by a rare gas. When the sodium oxide is X, the potassium oxide is Y, the remaining components are Z, and each composition point is represented by (X, Y, Z),
A point (2, 38, 60), B point (2, 0, 98), C point (4.2, 0,
95.8), the content ratio (wt%) of the area surrounded by points D (20, 20, 60) and excluding the line connecting points B and C
A gas discharge type display device having: