JPS5885254A - Attachment of fluorescent display tube - Google Patents

Abstract

PURPOSE:To prevent any influence of noises by shielding the opening, which is formed when a fluorescent display tube is attached to a case, by fixing a conductive member to the back surface of the case of the fluorescent display tube, and connecting said conductive member to an earth electric-potential. CONSTITUTION:A fluorescent tube 10 realizes a given display by making a phosphor provided on an anode to emit light by accelerating and controlling electrons discharged from a filament by means of a grid. A conductive member 15 is stuck to the back surface of the tube 10 with an adhesive or the like. After that, the tube 10 is attached to a plastic case 12, the inner wall of which is provided with a metallic film 14 by metalization, through conductive fixing members 16 and 16'. Therefore, by connecting the conductive members 15 to an earth electric-potential, incoming of an external eletromagnetic field from the opening formed due to the filter 13 of the case 12 as well as the radiation from the apparatus itself can be prevented. As a result, the reliability of the apparatus can be increased by preventing any influence of noises.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has developed a fluorescent display for preventing or reducing the occurrence of noise from external equipment when equipment using a fluorescent display tube is affected by noise from external equipment. The present invention relates to a method of attaching a light display tube.

A display tube is a type of triode electron tube, in which thermionic electrons in a filament are controlled by a grid, collide with an anode containing a phosphor, and emit light, and the anode that emits light is electrically selected. It is used to display information in various places, and is widely used in consumer products such as calculators and clocks, as well as in automobiles.

1 [= When used in highly reliable equipment such as a car speedometer display or a comviator terminal display, it is necessary to increase reliability to prevent malfunction of the equipment, and this is one of the countermeasures. As, BMC (Blecroma
It is necessary to improve the yield strength (genetic compatibility). That is, it is necessary to prevent the equipment from being affected by the electromagnetic ambient product term and also to prevent the generation of noise from affecting other equipment.

External noise sources include the forest, radiated electromagnetic fields from other equipment, transients from power lines, etc. Depending on the configuration, the equipment itself can also become a noise source and protect other equipment. Mainly for consumer electronics, plastic is used for economical reasons, and the rounded parts that constitute the body are not easily affected by external noise, and in some cases can easily become a source of noise.

To prevent this, the inner surface of the plastic case may be metallized to provide a shield, but when the equipment has a fluorescent display tube, noise may be radiated through the fluorescent display tube. A shield mechanism was required.

The object of the present invention is to provide a method for attaching a fluorescent display tube that eliminates these drawbacks.

According to the present invention, a fluorescent display tube is constructed in which electrons emitted from a filament are accelerated and controlled by a grid to cause a phosphor formed on an anode to emit light to obtain a desired display. A method for attaching a fluorescent display tube is obtained, which is characterized in that a conductor is applied to the outer surface of a vacuum vessel to be used, and the conductor is connected to ground potential.

The MK will be explained in detail below with reference to the drawings.

Figure 1 is a partial cross-section showing a fluorescent display tube.

The filament 1 is electrically heated to about 650@C and emits thermoelectrons. Grid 2 controls thermoelectrons from the filament. The wk electrode is made by depositing a phosphor in a certain shape on the conductive surface of the graphite, and emits light by the collision of thermoelectrons.

This emitted light is observed through a transparent cover glass 4.

This cover glass 4 and the substrate 5 constituting the anode are sealed and bonded to form a vacuum container. Electrodes such as an anode, a grid, and a filament are led out of the tube through a lead 6.

FIG. 2 is a sectional view showing the main parts of the fluorescent display tube. Ten fluorescent display tubes are attached to a printed circuit board 11 by soldering. The display contents of the fluorescent display tube can be viewed through a filter 13 attached to a glass case 12. A metal film 14 is formed on the inner surface of the plastic case 12 by metallization, and is connected to a ground potential KII to serve as a shield. however,
Since the filter 13 portion is not shielded, external electromagnetic fields may be incident from this portion or radiation from the device itself may become a noise source to other devices.

@3 Eel-1 is a sectional view showing an embodiment of the present invention, in which the same parts as in the conventional example of FIG. 2 are given the same numbers.

At and \, a conductor 15 is applied to the back surface of the fluorescent display tube 10. The conductor 15 is deposited by adhering a metal foil with an adhesive or by forming a metal film by sputtering.The conductor 15 deposited in this way is
The conductive metal parts 16.16'J are electrically connected, and the metal parts 16.16' wires are attached to the plastic case 12 with screws 17.17°.

Back conductor and metal parts 16°16' of fluorescent display tube 10
The filter 13 covers the electrical opening and is electrically connected to the metal film 14 on the inner surface of the plastic, thereby producing a shielding effect and preventing it from being affected by external electromagnetic fields and preventing it from being transmitted to other equipment as a noise source. Increase the effectiveness of preventing damage.

Of course, the shape of the metal parts 16 and 16' must be carefully selected to avoid contact with the leads of the fluorescent display tube, but it also depends on the electromagnetic environment in which the device is used and the degree of noise generated by the device itself. It is possible to simplify the structure.

One embodiment of the present invention has been described above.According to this, the electrical opening of the fluorescent display tube can be shielded very simply and economically, and is of great practical use.

[Brief explanation of the drawing]

Fig. 1 is a side view of a part of the fluorescent display tube including the m1 plane, Fig. 2 is a cross-sectional view showing the conventional installation of the fluorescent display tube, and Fig. 3 is a cross-sectional view showing one embodiment of the present invention. be. 1...Filament, 2...Grid, 3...Anode, 4...Cover glass,
5... Board, 6... Lead, lO...
... Fluorescent display tube, 11 ... Printed circuit board,
12...Plastic case, 13...
・Filter, 14-...Metal membrane, 15...
...Conductor, 16.16°...Metal parts, 17
, 17°...Mounting screw. 1st Flash Figure 2 Kaya 31!1

Claims (1)

[Claims] In a fluorescent display tube in which electrons emitted by a filament are accelerated and controlled by a grid to cause a phosphor formed on an anode to emit light to obtain a desired display, the outer surface of the tracheal container constituting the wrinkled wall light display tube 1. A method for attaching a fluorescent display tube, comprising: attaching a conductor to the surface of the tube and connecting the conductor to ground potential.