JPH10241609A - Fluorescent character display tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent support bodies for filament-shaped negative electrodes from generating an abnormal sound in filament energization. SOLUTION: An enclosure 1 of a fluorescent character display tube is made up by seal-attaching a box-shaped container part 3, whose lower surface is opened to a substrate 2 with a sealing material 4. Filament-shaped negative electrodes 5 are provided extended between a pair of support bodies 6 above the substrate 2. The support bodies 6 have a frame 7 which penetrates the seal parts of the enclosure 1 and a support part 8 fixed on the frame 7. The entire surface of a lower surface of the frame 7 is fixed onto an upper surface of the substrate 2 with the sealing material 4. The seal part of the enclosure 1 is shaped like a frame running along an outer circumferential edge of the substrate 2. The frame 7 of the support bodies 6 for supporting the filament-shaped negative electrodes 5 is fixed at the seal part, while being firmly attached over the whole surface, to an upper surface of the substrate 2 within the enclosure 1. For its use, an alternating current is applied to the filament- shaped negative electrodes 5, and even if the filament-negative electrodes 5 thereby vibrate, the vibration does not cause the support bodies 6 to resonate, and no unusual sound is generated between the support bodies 6 and the substrate 2.

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 having a structure in which a cathode support on which a filamentary cathode is stretched projects outside through a sealing portion of an envelope. It is.

[0002]

2. Description of the Related Art A fluorescent display tube has a flat box-shaped envelope in which various electrodes and the like are housed. As shown in FIG. 2, a general envelope 50 is configured by sealing a box-shaped container portion 52 having an open lower surface on the upper surface of a substrate 51. An anode (not shown) serving as a light-emitting display unit is formed on the upper surface of the substrate 51 in the envelope 50, a control electrode (not shown) is provided above the anode, and an electron source is provided above the control electrode. A filament cathode 53 is stretched. The filament cathode 53 is stretched between a pair of cathode supports 54 arranged at both ends of the envelope 50. Each cathode support 5
4 is a frame portion 55 that hermetically penetrates the sealed portion of the envelope 50, and a support portion 56 fixed to the frame portion 55.
And One of the support portions 56 of the pair of cathode supports 54 is a support for fixing one end of the filament cathode 53, and the other support portion 56 is an anchor for fixing and pulling the other end. The cathode support 54 in FIG. 2 is the side having the anchor.

[0003]

In the structure described above, the sealing portion of the envelope 50 has a shape of the lower end surface of the container portion 52 or a frame shape along the outer peripheral edge of the substrate 51. The frame 55 of the cathode support 54 supporting the filament cathode 53 is
Although it is fixed at the sealing portion, it is not adhesively fixed to the substrate inside the envelope 50. That is, the envelope 5
0, the cathode support 54 excluding the sealing portion
Is in contact with the upper surface of the substrate 51 except for the sealing portion or with a small gap, but is not fixed.

In driving the fluorescent display tube, when an alternating current is applied to the filament cathode 53, the filament cathode 53 resonates at the frequency of the alternating current and vibrates, and this is an anchor having a spring property (support portion 56). The vibration is transmitted to the frame 55 through the frame 55, and a non-fixed portion of the frame 55 is vibrated to generate an unpleasant noise with the substrate 51 in some cases.

According to the present invention, in a fluorescent display tube having a structure in which a cathode support of a filament cathode penetrates a sealed portion of an envelope, abnormal noise is prevented from being generated when an alternating current is applied to the filament cathode. It is intended to be.

[0006]

According to a first aspect of the present invention, there is provided a fluorescent display tube, comprising: a flat box-shaped envelope formed by sealing a substrate and a container; and the envelope disposed on the substrate. A fluorescent display tube having a cathode support penetrating through a sealed portion of the container, and a filament cathode stretched on the cathode support inside the envelope, wherein an alternating current is applied to the filament cathode Wherein the cathode support and the substrate are sealed and fixed inside the envelope.

According to a second aspect of the present invention, there is provided the fluorescent display tube according to the first aspect, wherein the cathode support has a plate shape, and a lower surface of the cathode support excluding the sealing portion is provided.
It is characterized by being fixed to the upper surface of the substrate with a sealing material containing low melting point glass.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. The envelope 1 of the fluorescent display tube of this example is
A box-shaped container portion 3 having an open lower surface is sealed to the upper surface of the substrate 2. For sealing, a sealing material 4 mainly composed of low melting point glass is used. The substrate 2 is made of a glass plate, and the container portion 3 is also made by assembling a plurality of glass plates with a sealing material.

An anode (not shown) serving as a light-emitting display portion is formed on the upper surface of the substrate 2 in the envelope 1, and above it,
A control electrode (not shown) is provided, and a filament cathode 5 as an electron source is stretched above the control electrode.

The filament cathode 5 is stretched between a pair of cathode supports 6, 6 arranged at both ends of the envelope 1. Each cathode support 6 includes a frame 7 that hermetically passes through the sealed portion of the envelope 1, and a support portion 8 fixed to the frame 7. One supporting portion 8 of the pair of cathode supports 6, 6 is a support for fixing one end of the filamentary cathode 5, and the other supporting portion 8 is an anchor for fixing and pulling the other end.

The frame 7 is made of an alloy having a coefficient of thermal expansion close to that of glass, such as a 426 alloy composed of 42% of Ni, 6% of Cr, and the balance of Fe from a portion penetrating the sealed portion of the envelope 1, The support portion 8 which requires spring properties like an anchor is made of a material such as stainless steel.

In this embodiment, the entire lower surface of the frame 7 is fixed to the upper surface of the substrate 2 with a sealing material 4. In order to fix the frame 7 to the substrate 2 in this manner, FIG.
As shown in (b), the sealing paste 4 is applied to a predetermined position on the upper surface of the substrate 2 with which the frame 7 contacts, together with the sealing portion of the envelope 1. At the time of assembling, the frame 7 to which the support portion 8 is welded is placed thereon, and the container portion 3 is further placed and assembled, heated and sealed.

In the structure described above, the sealing portion of the envelope 1 has a shape of the lower end surface of the container portion 3 or a frame shape along the outer peripheral edge of the substrate 2. The frame 7 of the cathode support 6 that supports the filament cathode 5 is fixed at the sealing portion, and is fixed on the entire upper surface of the substrate 2 inside the envelope 1. That is, inside the envelope 1, the lower surface of the cathode support 6 is entirely fixed to the upper surface of the substrate 2.

Since the frame 7 is fixed to the substrate 2 as described above, an alternating current is applied to the filamentary cathode 5 in use, so that even if the filamentary cathode 5 vibrates, the vibration causes the cathode support 6 to vibrate. No resonance occurs, and no abnormal noise is generated between the cathode support 6 and the substrate 2. Further, since the cathode support 6 does not vibrate, the height of the cathode support 6 on the substrate 2 is stabilized.

In the above-described example, the entire lower surface of the frame 7 is fixed to the upper surface of the substrate 2, but at least one portion of the lower surface of the frame 7 other than the sealing portion of the envelope 1 is fixed to the upper surface of the substrate 2. , A corresponding effect of preventing the vibration of the frame 7 can be obtained.

[0016]

According to the present invention, the resonance of the cathode support due to the vibration of the filamentary cathode can be prevented, and the generation of abnormal noise between the cathode support and the substrate can be prevented. In addition, since the height of the cathode support on the substrate is stabilized, the light emission luminance of the display unit is stabilized.

[Brief description of the drawings]

FIG. 1A is a view taken along line aa of FIG. 1B, and is a plan view of a substrate according to an embodiment of the present invention. FIG. 1B is a plan view of an embodiment of the present invention. FIG.

FIG. 2A is a view taken along line aa of FIG. 2B, and is a plan view of a substrate in an example of a conventional fluorescent display tube;
(B) is a sectional view of an example of a conventional fluorescent display tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Enclosure 2 Substrate 3 Container part 4 Sealing material 5 Filament cathode 6 Cathode support

Claims (2)

[Claims] 1. A flat box-shaped envelope formed by sealing a substrate and a container, a cathode support disposed on the substrate and penetrating a sealed portion of the envelope, A fluorescent display tube having a filament cathode stretched on the cathode support inside a vessel, wherein an alternating current is applied to the filament cathode, wherein the cathode support and the substrate are provided inside the envelope. And a fluorescent display tube characterized by being fixed by sealing. 2. The method according to claim 1, wherein the cathode support has a plate shape, and a lower surface of the cathode support excluding the sealing portion is fixed to an upper surface of the substrate with a sealing material containing low-melting glass. The fluorescent display tube according to claim 1.