JPH0427086Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The invention provides an internal electrode at one end of a bulb in the shape of an elongated hollow rod, and a strip-like electrode along the axial direction on the outer surface of the bulb. The present invention relates to a discharge lamp which is provided with external electrodes and generates glow discharge between the internal electrodes and the external electrodes.

(Prior Art) Recently, attempts have been made to use discharge lamps as direct indicators in display panels for automobile meters, electrical equipment, and the like.

In other words, the discharge lamp is configured in the shape of a needle, that is, the bulb is an extremely thin hollow rod with an inner diameter of about 2 mm to 3 mm, and one end of this discharge lamp is attached to the rotation pointer shaft of the meter, so that the rotation pointer shaft can be easily adjusted. When the lamp rotates, the discharge lamp also rotates as a unit, so that the discharge lamp functions as a pointer.
Moreover, when this discharge lamp is turned on, it illuminates the display scale, so there is an advantage that no special illumination is required.

A discharge lamp used as a pointer for such a meter has an internal electrode inside a bulb that is shaped like a long, slender hollow rod, and a band-shaped external electrode that runs along the axial direction on the outer surface of the bulb. The bulb is configured to supply high-frequency power between the bulb and the external electrode to generate glow discharge within the bulb.

Conventionally, a structure has been adopted in which covered cords are connected to the internal electrodes and external electrodes, respectively, and the internal electrodes and external electrodes are connected to a high frequency power source through these covered cords.

(Problem to be solved by the invention) However, in the case where the covered cord is connected as described above, the covered cord is connected to the lead wire connected to the internal electrode by soldering or caulking. The work was troublesome.

Moreover, since the discharge lamp used as the meter pointer is attached to a rotating pointer shaft and rotates as the pointer shaft rotates, if the covered cord is derived from the discharge lamp, These coated cords are twisted or bent as the discharge lamp rotates, and such deformation of the coated cords tends to lead to breakage over time. Furthermore, the deformation of the covered cord becomes a resistance to the rotating operation of the discharge lamp, and there is a fear that the operation of the meter needle, which requires high precision and quick response, may be hindered.

The present invention eliminates the use of special coated cords that are likely to break, and attempts to provide a discharge lamp that is simple in structure and does not interfere with rotational operation when used as a meter pointer. It is something.

[Structure of the invention] (Means for solving the problems) The present invention provides a power receiving terminal film made of conductive paste connected to the internal electrode on the outer surface of the end of the bulb in which the internal electrode is sealed, and Another power receiving terminal film made of conductive paste is provided at a distance in the axial direction from this power receiving terminal film and connected to the external electrode, and these power receiving terminal films have elasticity on the power supply terminal tongue piece on the power source side. It is characterized in that it is connected to a power source by touching it.

(Function) According to the present invention, the power receiving terminal film made of conductive paste provided on the outer surface of the bulb comes into elastic contact with the power supply terminal tongue piece on the power source side and is connected to the power source, so a special coated cord is not required. The structure is simple, there is no need to connect the lead wire, and when used as a meter pointer, it does not interfere with the turning operation of the discharge lamp, resulting in high accuracy. It also enables quick response and eliminates the worry of disconnections.

(Example) The present invention will be described below based on an example shown in the drawings.

In the figure, 1 indicates a discharge lamp used as a pointer for automobile speedometers, etc. The discharge lamp of this embodiment is a cold cathode discharge lamp, and this discharge lamp 1 is equipped with a glass bulb 2 in the shape of an elongated hollow rod. There is. The glass bulb 2 has, for example, an outer diameter of 2.5 mm, a total length of about 60 mm, and is formed into a substantially needle shape.

A cold cathode 3 is sealed as an internal electrode at one end of the bulb 2, and the cold cathode 3 is connected to a lead wire 4 that passes through the sealed end of the bulb 2 in an airtight manner.

A phosphor coating 5 is formed on the inner surface of the bulb 2. In addition, a discharge gas consisting of at least one of xenon and krypton is sealed in the bulb 2 at a pressure of 50 torr or more.

An external electrode 6 is provided on the outer surface of the bulb 2 in the form of a band along the axial direction. The external electrode 6 is constructed by applying a paste such as carbon phenol or silver epoxy in the form of a strip to a predetermined length of the bulb 2, and firing the paste.

A light-shielding coating 7 is formed on the outer surface of the bulb 2. The light-shielding film 7 is formed on the surface of the bulb 2 on which the external electrode 6 is provided, and also covers this external electrode 6. The light-shielding film 7 extends in the axial direction on the surface opposite to the surface on which the external electrode 6 is provided. A slit portion 8 in which no coating 7 is formed is formed. That is, as shown in cross section in FIG. 3, a band-shaped external electrode 6 is provided on the outer surface of the bulb 2, and a light-shielding coating 7 is formed at a position 180 degrees opposite to the external electrode 6. In this case, a slit portion 8, which is not a slit portion, is formed. Therefore, the light within the bulb 2 is emitted to the outside only through the slit portion 8, and therefore the cold cathode fluorescent lamp 1 has an aperture shape.

In such a bulb 2, a first power receiving terminal film 10 is formed on the outer surface of the end portion where the internal electrode 3 is sealed. This first power receiving terminal film 10 is
The conductive paste is made of a conductive paste such as silver epoxy and is formed on the end face of the bulb 2 and over the entire outer surface of the bulb 2 over a predetermined length in the axial direction from the end face and continuously around the entire circumference. The first power receiving terminal film 10 is connected to the cold cathode 3 and to a lead wire 4 that passes through the sealed end of the bulb 2 in an airtight manner.

Further, a second power receiving terminal film 11 is formed on the outer surface of the bulb 2 so as to be spaced apart from the first power receiving terminal film 10 in the axial direction. The second power receiving terminal film 11 is also made of a conductive paste such as silver epoxy, and is formed circumferentially spaced apart from the first power receiving terminal film 10 in the axial direction and having a predetermined width.
The second power receiving terminal film 11 is formed on the outer surface of the light shielding film 7 while avoiding the slit portion 8 of the light shielding film 7.
is connected to the external electrode 6.

The cold cathode discharge lamp 1 configured in this manner is attached to a lamp holder 20.

The lamp holder 20 is made of electrically insulating material and has a cross section U.
It is formed in a letter shape, and first and second power supply terminal tongue pieces 21 and 22 are fixed spaced apart from each other in the longitudinal direction. These power supply terminal tongue pieces 21 and 22 are formed by bending conductive plate springs such as phosphor bronze into a substantially U shape, and are supported by clamping pieces 23a and 23b facing each other as shown by the imaginary lines in FIG. The valve 2 is held between the valves 2 and 2.

The lamp holder 20 has a meter pointer shaft 25
The pointer shaft 25 is fixed to the pointer shaft 25, and rotates integrally when the pointer shaft 25 rotates.

Note that the pointer shaft 25 of this embodiment is constituted by a hollow shaft (not shown), and there are two inside the hollow pointer shaft 25.
A coated cord (not shown) is inserted through the cord, one end of which is connected to the first and second power supply terminal tongue pieces 21 and 22, respectively, and the other end is connected to a high frequency power source. .

The cold cathode discharge lamp 1 is adapted to be attached to a lamp holder 20 at the end where the internal electrode 3 is sealed. That is, the first power receiving terminal film 10 and the second power receiving terminal film 11 formed on the outer surface of the bulb 2 are opposed to the first power feeding terminal tongue piece 21 and the second power feeding terminal tongue piece 22 of the lamp holder 20. , when this lamp is pushed into the lamp holder 20 from the opening side, the first and second power supply terminal tongue pieces 2
The holding pieces 23a and 23b of 1 and 22 respectively hold the first power receiving terminal film 10 and the second power receiving terminal film 11.
The valve 2 is mechanically clamped via the . Therefore, the cold cathode discharge lamp 1 is attached to the lamp holder 20. In this case, since the first and second power feeding terminal tongues 21 and 22 are in electrical contact with the first power receiving terminal film 10 and the second power receiving terminal film 11, respectively, the first and second power feeding terminal tongues The inner electrode 3 and the outer electrode 6 are connected to a high frequency power source by means of a covered cord connected to the pieces 21, 22.

According to such a configuration, the end portion of the cold cathode discharge lamp 1 in which the internal electrode 3 is sealed is connected to the lamp holder 20.
In this case, the lamp is held between the first power supply terminal tongue piece 21 and the second power supply terminal tongue piece 22, which are located at two locations apart in the axial direction, so that the lamp is supported even though only the end portion is supported. The support strength is high.

The lamp holder 20 is fixed to a pointer shaft 25, and when the pointer shaft 25 rotates, the lamp holder 2
0 is also rotated integrally, so the lamp holder 2
The discharge lamp 1 attached to 0 is also rotated in the direction of arrow A shown in FIG.

Furthermore, high-frequency power is transmitted to the first power receiving terminal film 10 and the second power receiving terminal film 10 through the first power feeding terminal tongue piece 21 and the second power feeding terminal tongue piece 22 by a coated cord (not shown).
The first power receiving terminal film 10 and the second power receiving terminal film 11 supply the internal electrode 3 and the external electrode 6. Therefore, within the bulb 2, the internal electrode 3 and Glow discharge is generated between the external electrodes 6.

This glow discharge excites the phosphor coating 5 and prompts it to emit light, which is emitted from the slit portion 8 to the outside. Therefore, in addition to the bulb 2 being thin, the slit portion 8 exhibits an even narrower band of light, making the discharge lamp 1 suitable for indicating a display scale as a pointer. Moreover, it shines by itself,
No other special light source is required.

Regarding the discharge lamp 1 itself, since the first power receiving terminal film 10 and the second power receiving terminal film 11 made of conductive paste such as silver epoxy were formed on the outer surface of the bulb 2, the first power receiving terminal film 10 and the second power receiving terminal film 11 were formed on the outer surface of the bulb 2. The power supply is connected simply by contacting the first and second power supply terminal tongues 21 and 22, so a covered cord extending from the bulb 2 is not necessary.

For this reason, the discharge lamp 1 has a reduced number of parts and a simple structure.

Further, a lead wire 4 connected to the cold cathode 3 and passed through the sealed end of the valve 2 in an airtight manner is connected to the cold cathode 3.
By applying a conductive paste to the outer surface of the terminal, it is automatically connected to the first power receiving terminal film 10, so no special connection work is required.

In addition, the pointer shaft 25 of this embodiment is constituted by a hollow shaft, and two coated cords (not shown) are inserted into the hollow pointer shaft 25, and one end of these coated cords is connected to the first and second wires, respectively. 2, and the other end is connected to a high frequency power source, so even if the pointer shaft 25 rotates, the covered cord will rotate together, and the covered cord will connect to the pointer shaft. 25 is not obstructed, the covered cord is not deformed such as twisting or bending, and the rate of wire breakage is low.

Note that the present invention is not limited to the configuration of the above embodiment.

That is, in the above embodiment, the case where the discharge lamp of the present invention is used as a pointer of a meter has been described, but the present invention is not limited to this, and the discharge lamp may be used as a backlight of a liquid crystal display device.

Furthermore, the internal electrodes 3 may be provided at both ends of the bulb 2.

Furthermore, the electrode is not limited to a cold cathode type, but may be a hot cathode type.

Further, the discharge lamp is not limited to one having the light-shielding coating 7 or the slit portion 8.

[Effect of the invention] As explained above, according to the invention, the power receiving terminal film made of conductive paste provided on the outer surface of the bulb comes into elastic contact with the power supply terminal tongue piece on the power source side and is connected to the power source. Therefore, there is no need for a special coated cord, the structure is simple, and there is no need for connection work with lead wires, and when used as a meter pointer, it does not interfere with the rotating operation of the discharge lamp. This enables highly accurate and quick response, and there is no need to worry about wire breakage.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is an exploded perspective view of a discharge lamp and a lamp holder, Fig. 2 is a rear view of the discharge lamp, and Fig. 3 is a sectional view taken along the line - - in Fig. 2. It is. 1... cold cathode discharge lamp, 2... bulb, 3... internal electrode, 4... lead wire, 6... external electrode, 7...
...Light shielding film, 8...Slit portion, 10...First power receiving terminal film, 11...Second power receiving terminal film, 20...
... Lamp holder, 21 ... First power supply terminal tongue piece,
22...Second power supply terminal tongue piece, 25...Pointer shaft.

Claims (1)

[Scope of utility model registration request] In a discharge lamp in which an internal electrode is provided at the end of a bulb in the shape of an elongated hollow rod, a band-shaped external electrode is provided along the axial direction on the outer surface of the bulb, and discharge gas is sealed in the bulb. A power receiving terminal film made of conductive paste is provided on the outer surface of the end of the bulb in which the electrode is sealed, and is connected to the internal electrode, and is connected to the external electrode at a distance in the axial direction from the power receiving terminal film. A discharge lamp characterized in that another power receiving terminal film made of conductive paste is provided, and the power receiving terminal film is connected to a power source by coming into elastic contact with an elastic power supply terminal tongue piece on the power source side.