JPH06163004A - Display tube for light source - Google Patents

Abstract

PURPOSE:To prevent the occurrence of crack on a glass face by forming a sealing structure where the contact angle, of at least one of a glass bulb and a front glass, against the glass face of frit glass is an acute angle. CONSTITUTION:In the open end of a glass bulb 1, a front glass 2, of which a fluorescent screen 5 and a metal-backed film 6 are formed on its inner face side, is bonded, arranged and sealed so that a contact angle through frit glass 3 becomes an acute angle from the edge of the inner face side along the inner wall face of the bulb 1. Accordingly, when heat is conducted to the bulb 1 so as to induce temperature change, no sharp thermal impact is allowed to be applied as no wedge-like recess exists between the bulb l and the glass 2. Thereby it is possible to prevent the occurrence of crack in the glass, and improve its reliability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source display tube, and more particularly to a sealing structure formed by sealing a windshield and a glass bulb with frit glass.

[0002]

2. Description of the Related Art FIG. 5 is a cross-sectional view of a main part showing the structure of a conventional fluorescent display tube for a light source. In the figure, 1 is a cylindrical glass bulb made of, for example, lead glass, 2 is a windshield made of, for example, soda glass, which is sealed at one open end of the glass bulb 1 via a frit glass 3. The glass bulb 1, the windshield 2, and the frit glass 3 constitute a cylindrical glass bulb assembly 4 whose one end is sealed. Reference numeral 5 is a fluorescent screen formed on the back surface of the windshield 2, 6 is an Al metal back film formed on the fluorescent screen 5, and 7 is a glass bulb 1.
Carbon film formed on the inner wall surface of the windshield 2 side of
Reference numeral 8 is a Ba getter film formed between the Al metal back film 6 and the carbon film 7 and electrically connected to each other.

Further, 10 is a stem structure sealed to the other open end of the glass bulb structure 4, and 11 is the glass bulb 1.
A stem glass made of, for example, lead glass sealed at the other open end of the frit glass 12 via a frit glass 12, 13 is an exhaust pipe integrally formed with the stem glass 11, and 14 is a lead pin 15a on the stem glass 11. A cathode assembly fixedly arranged at the tip of the cathode lead 16.
Reference numeral 7 denotes an anode lead 18 which is connected to the lead pin 15b.
Cylindrical anode ring fixedly mounted on the tip of
Reference numeral 9 denotes a Ba getter fixed to the tip of the anode ring 17, and 20 denotes a valve spacer contact fixed to the tip of the anode ring 17 and electrically connected to the carbon film 7 in contact therewith.

In such a structure, the cathode assembly 1
The phosphor screen 5 is excited by the electron beam emitted from the phosphor 4, and the emission color corresponding to the phosphor is transmitted through the windshield 2 to be emitted and displayed toward the front side.

[0005]

However, in the conventional light source display tube, the frit glass 3 for sealing the windshield 2 and the glass bulb 1 to each other as shown in the enlarged cross section of the main part of FIG. 2 has a sealing structure in which the contact angle of the glass surface of the glass bulb 1 and the glass surface of the glass bulb 1 is an acute angle. Therefore, a sudden temperature change causes cracks 21 in the windshield 2 and the glass bulb 1 to reduce reliability. There was a problem.

Therefore, the present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to prevent the occurrence of cracks in the windshield and the glass bulb and to improve the reliability. To provide a display tube for use.

[0007]

In order to achieve such an object, the present invention has a sealing structure in which at least one of a glass bulb and a windshield has an obtuse contact angle with respect to the glass surface of frit glass. There is.

[0008]

In the sealing structure of the present invention, the thermal expansion strain of the glass bulb and the windshield due to a sudden temperature change is not locally concentrated.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration of an embodiment of a light source display tube according to the present invention, and the same parts as those in the above-mentioned drawings are designated by the same reference numerals. In the figure, at the opening end of the glass bulb 1, a windshield 2 having a phosphor screen 5 and an Al metal back film 6 formed on the inner surface is provided with a frit glass along the inner wall surface of the glass bulb 1 from a corner portion on the inner surface side. It is adhesively arranged and sealed so that the contact angle by 3 is an obtuse angle. After the sealing structure of the frit glass 3 where the contact angle becomes an obtuse angle is formed, the Ba getter film 8 is formed on the frit glass 3 as shown in FIG. 2 to form the Al metal back film 6 and the carbon film. 7 and 7 are electrically connected.

Next, a method of forming the sealing structure configured as described above will be described. First, as shown in FIG. 3, the frit glass 3 is coated on the step portion at the peripheral edge of the inner surface of the windshield 2 on which the phosphor screen 5 and the Al metal back film 6 are formed, and is calcined and placed. In this case, the coating size of the frit glass 3 is a. Next, the frit glass 3 is coated on the open end of the glass bulb 1 and from the open end to the inner wall surface portion, and calcined and placed. In this case, the coating size of the frit glass 3 is b. Next, the frit glass 3 and the glass bulb 1 on which the frit glass 3 is preliminarily fired are combined with the frit glass 3 on the coating side and fired at a predetermined temperature to bond and seal them. In this case, the relationship between the coating size a and the coating size b of the frit glass 3 is set to b> a. Specifically, by setting b> 1.5a or b> a + 2.00 mm, a sealing structure in which the contact angle after sealing is an obtuse angle as shown in FIG. 1 can be obtained.

According to this structure, the frit glass 3 has the sealing structure by the sealing so that the contact angle with which the glass surface of the inner wall surface of the glass bulb 1 contacts is obtuse.
Since there is no wedge-shaped recess between the glass bulb 1 and the windshield 2 when heat is conducted to the glass bulb 1 to change the temperature, abrupt thermal shock is not applied and thus cracks are prevented. You can

FIG. 4 is a sectional view showing the structure of a light source display tube according to another embodiment of the present invention, and the same parts as those in the above-mentioned figures are designated by the same reference numerals. 1 is different from FIG. 1 in the case where the inner diameter of the windshield 2 is smaller than the opening diameter of the glass bulb 1 or the opening diameter of the glass bulb 1 is smaller than the inner diameter of the windshield 2. Even if it is large, it is possible to form a sealing structure by sealing in which the frit glass 3 has an obtuse contact angle with the windshield 2 and the glass surface of the glass bulb 1. Although not shown, a Ba getter film 8 is formed on the frit glass 3 after the sealing structure of the frit glass 3 having an obtuse contact angle is formed, and the Al metal back film 6 is formed as in FIG. The carbon film 7 and the carbon film 7 are electrically connected.

According to this structure, the frit glass 3 has a sealed structure in which the contact angle with which the front glass 2 and the glass surface of the inner wall surface of the glass bulb 1 contact each other is an obtuse angle. In addition to the above-described effects when the above-mentioned operation is performed, it becomes difficult to apply a rapid thermal shock to the windshield 2, and therefore, it is possible to prevent the glass bulb 1 and the windshield 2 from being cracked.

[0014]

As described above, according to the present invention,
Since at least one of the glass bulb and the windshield in the sealing structure of the glass bulb and the windshield has a sealing structure in which the contact angle of the frit glass with respect to the glass surface is an obtuse angle, the occurrence of cracks on the glass surface can be prevented. Further, it has an extremely excellent effect that a highly reliable display tube for a light source is obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing a sealing structure according to an embodiment of a light source display tube according to the present invention.

FIG. 2 is a cross-sectional view showing the configuration of an embodiment of a light source display tube according to the present invention.

FIG. 3 is a cross-sectional view illustrating a method of forming a sealing structure for a light source display tube according to the present invention.

FIG. 4 is a sectional view showing a sealing structure of another embodiment of the light source display tube according to the present invention.

FIG. 5 is a cross-sectional view showing a configuration of a conventional light source display tube.

FIG. 6 is a cross-sectional view illustrating a problem of a sealing structure in a conventional light source display tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical glass bulb 2 Front glass 3 Frit glass 4 Glass bulb structure 5 Fluorescent surface 6 Al metal back film 7 Carbon film 8 Ba getter film 9 Anode electrode 10 Stem structure 11 Stem glass 12 Frit glass 13 Exhaust pipe 14 Cathode structure 15a Lead pin 15b Lead pin 16 Cathode lead 17 Anode ring 18 Anode lead 19 Ba getter 20 Valve spacer contact 21 Crack

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tokuhide 700 Wada, Ueno Town, Ise City, Mie Prefecture 700 Ida Electronics Industry Co., Ltd. (72) Inventor Sashiro Uemura 700 Wada, Ueno Town, Ise City, Mie Prefecture Within Ise Electronics Industry Co., Ltd.

Claims (1)

[Claims] 1. A windshield having a phosphor screen formed on an inner surface thereof, and a glass bulb having an anode electrode formed on an inner wall surface thereof.
In a light source display tube configured to be sealed with a frit glass on a stem glass having a cathode structure mounted thereon, at least one of the glass bulb and the windshield is a sealing tube having an obtuse contact angle with respect to a glass surface of the frit glass. A display tube for a light source, which has a stop structure.