JPH0389447A - Low-pressure discharge lamp - Google Patents

Abstract

PURPOSE:To surely connect receiving terminals to external feeding terminals by covering a bulb with a receiving terminal made of a conducting metal molding such as a sleeve, a ring and a cap in contact with a conduction section made of a baked film of conducting paste. CONSTITUTION:The first receiving terminal 10 and the second receiving terminal 11 are formed with a metal cap and a ring made of phosphor bronze or the like and cover a bulb 2, and they are connected to an inner electrode 3 and an outer electrode 6 respectively. When a lamp 1 is fitted to or removed from a holder 20, the first feeding terminal tongue 21 and the second feeding terminal tongue 22 are rubbed with the first receiving terminal 10 and the second receiving terminal 11, but they are not peeled off. Electric connection is surely maintained. The conduction section 6 connected with the receiving terminal 11 is made of a baked film of conducting paste, thus it is not peeled off when slid against the receiving terminal 11. The lamp 1 is simply fitted or removed via receiving terminals, and connection is secured.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention provides a conductive part made of baked conductive paste on the outer surface of a bulb, and brings this conductive part into contact with an external power supply terminal. The present invention relates to a low-pressure discharge lamp that is electrically connected to the lamp.

(Prior Art) Recently, attempts have been made to use low-pressure discharge lamps as display indicators on display panels of audio equipment, measuring instruments, and the like.

For example, a low-pressure discharge lamp such as a xenon glow discharge tube is shaped into an extremely thin hollow needle with an inner bulb diameter of about 2 mm to 3 mm, and one end of this discharge lamp is attached to the rotation pointer shaft of a meter. A device has been developed in which the discharge lamp rotates as a unit, and in this device, the discharge lamp functions as a pointer, and when the discharge lamp is turned on, it emits light itself. Since the display scale part is illuminated by the light, there is an advantage that no other special illumination is required.

A discharge lamp used as a pointer for such a meter is equipped with an internal electrode inside a bulb in the shape of a long, slender hollow rod, and a band-shaped external electrode is provided along the axial direction on the outer surface of this bulb. The bulb is configured to apply high frequency power between the bulb and the external electrode to generate glow discharge within the bulb.

A light-shielding coating made of synthetic resin is formed on the outer surface of the bulb, and this light-shielding coating is formed except for a thin strip-shaped light-transmitting slit extending in the axial direction of the bulb. It is designed to emit light from. Therefore, this type of discharge lamp is an aperture-shaped lamp, and the light-emitting part of the pointer is shaped like an extremely thin needle.

By the way, conventionally, a structure has been adopted in which coated cords are connected to the internal electrodes and external electrodes, respectively, and the internal electrodes and the external electrodes are connected to a high-frequency power source through these coated cords.

However, those using such coated cords are
The above-mentioned covered cord is connected to the lead wire connected to the internal electrode by soldering or caulking, so the connection work is troublesome.Moreover, in a discharge lamp used as a meter pointer, it is attached to the rotating pointer shaft. If the covered cords are led out from the discharge lamp, the covered cords may become twisted or bent due to the turning movement of the discharge lamp. Deformation can easily lead to wire breakage due to long-term use. Further, the deformation of the covered cord acts as a resistance to the turning movement of the discharge lamp, which also has the disadvantage of impeding the operation of the meter as a needle, which requires highly accurate and quick response.

For this reason, a first power receiving terminal is provided on the outer surface of the end of the bulb in which the internal electrode is sealed, and is made of a film made of fired conductive paste and connected to the internal electrode. Further, the external electrode is formed of a film made of a fired conductive paste, and a second power receiving terminal is provided which is connected to the external electrode and is made of a film made of a fired conductive paste. The first and second power receiving terminals are brought into contact with the first and second power supply terminals provided on the valve holder, and the structure is such that the first and second power receiving terminals are connected to the power supply through the first and second power supply terminals.
is considered.

In this way, there is no need for a covered cord, there is no need to worry about wire breakage, and when used as a pointer, there will be no problem of impeding rotation.

(Problem to be Solved by the Invention) However, the first and second power supply terminals are formed by bending a conductive metal piece into a substantially U-shape, and support the bulb by the elastic clamping action of the conductive metal piece. However, due to the elastic force caused by this clamping, it came into contact with each node 1 and the second power receiving terminal.

This type of impact occurs when the first and second power receiving terminals come into sliding contact, or in other words, rub against each other, when the lamp is attached or removed.For this reason, the first and second power receiving terminals are formed of a film made of fired conductive paste. These coatings may peel off.

Peeling of the coating causes poor electrical connection with the power supply terminal.

The present invention provides a low-pressure discharge lamp that can prevent peeling of a conductive part formed of a film made of fired conductive paste, such as the external electrode, and ensure electrical connection with a power supply terminal. That is.

[Structure of the Invention] (Means for Solving the Problems) The first aspect of the present invention is to cover a bulb with a power receiving terminal made of a conductive metal molded product such as a sleeve, a ring, or a cap, The present invention is characterized in that the conductive paste is brought into contact with a conductive portion formed of a fired film and is electrically connected to an external power supply terminal.

(Function) According to the present invention, the power receiving terminal of the conductive part formed of a film formed by firing a conductive paste is made of a conductive metal, so that it does not peel off even if it comes into sliding contact with the power feeding terminal.
A reliable electrical connection can be maintained, and troublesome steps such as a firing process are not required.

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

In the figure, numeral 1 indicates a low-pressure discharge lamp used as a pointer for a meter of audio equipment, and the discharge lamp in this embodiment is a cold cathode discharge lamp.

This discharge lamp 1 consists of a glass bulb 2 in the shape of an elongated hollow rod, and the glass bulb 2 has an outer diameter of, for example, 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.

As shown in FIGS. 3 and 4, a phosphor wave film 5 is formed on the inner surface of the bulb 2.
A discharge gas made of at least one of xenon and krypton is sealed within the chamber at a pressure of 50 torr or more.

On the outer surface of the bulb 2, an external electrode 6 formed of a band-shaped coating is provided along the axial direction.

This external electrode 6 corresponds to the conductive part of the present invention, and is formed by applying a conductive paste such as carbon phenol or silver epoxy to a predetermined length of the bulb 2 in the form of a strip, and baking it to form a film. It is structured as follows.

A first power receiving terminal 1o is attached to the outer surface of the end portion of the bulb 2 in which the internal electrode 3 is sealed. This first
The power receiving terminal 10 is a cap-shaped conductive metal plate made of phosphor bronze or the like, and is attached to the end of the bulb 2. The first power receiving terminal 1o is connected to the lead wire 4 by pressing the end of the bulb 2 against the lead wire 4 which is passed through the end of the bulb 2 in an airtight manner.

Further, on the outer surface of the bulb 2, the first power receiving terminal 10 is provided.
A second power receiving terminal 11 is provided at a position spaced apart from each other in the axial direction. The second power receiving terminal 12 is made by bending a piece of conductive metal such as phosphor bronze into a ring shape, and is placed over the bulb 2 . This second power receiving terminal 12 is elastically attached to the bulb 2 and is connected to an external electrode 6 made of paste formed on the outer surface of the bulb 2.

Note that this second power receiving terminal 11 is fitted into the bulb 2 while avoiding the slit portion 8 of the light-shielding coating 7, which will be described later.

A light-shielding coating 7 is formed on the outer surface of the bulb 2.

The light-shielding film 7 has components of carbon, epoxy resin, and adhesive, and is formed on the surface of the bulb 2 on which the external electrode 6 is provided, covering the external electrode 6, and also on the surface of the bulb 2 on which the external electrode 6 is provided. A light transmitting slit portion 8 that extends in the axial direction and does not form the light shielding film 7 is formed on the surface opposite to the above surface.

That is, as shown in cross section in FIG. 3, the outer surface of the bulb 2 is provided with an external electrode 6 on one side, and a light-shielding coating is provided on the other side 180 degrees opposite to the external electrode 6. A light transmitting slit portion 8 is formed in which no portion 7 is formed. Therefore, the light inside the bulb 2 is emitted to the outside only through the light transmission slit section 8, and therefore, the cold cathode fluorescent lamp 1 has an aperture shape.

The cold cathode discharge lamp 1 configured in this way has a lamp holder 2.
Attached to 0.

The lamp holder 20 is made of an electrically insulating material and has a U-shaped cross section, and first and second power supply terminal tongues 21 and 22 are fixed to the lamp holder 20 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.
The clamping pieces 23a face each other as shown by imaginary lines in the figure.

The valve 2 is held between the parts 23b.

The lamp holder 20 is fixed to a pointer shaft 25 of the meter, and is configured to rotate integrally with this pointer shaft 25.

Note that the pointer shaft 25 of this embodiment is constituted by a hollow shaft (not shown), and two covered cords (not shown) are inserted into this hollow pointer shaft 25, and one end of each of these covered cords is connected to the 1 and 2nd power supply terminal tongue piece 21, 22
The other end is connected to a high frequency power source.

The cold cathode discharge lamp 1 is adapted to be attached to the lamp holder 20 at the end thereof where the internal electrode 3 is sealed. That is, the first power receiving terminal 10 and the second power receiving terminal 11 attached to the outer surface of the bulb 2 are connected to the lamp holder 20.
The first power supply terminal tongue piece 21 and the second power supply terminal tongue piece 2
When the lamp 1 is pushed in from the opening side of the lamp holder 20, the first and second power supply terminal tongue pieces 2
The clamping pieces 23a and 23b of 1.22 clamp the first power receiving terminal 10 and the second power receiving terminal 11, and thereby the cold cathode discharge lamp 1 is mechanically supported by the lamp holder 20. In this case, the first and second power supply terminal tongue pieces 21.22 are in electrical contact with the first power reception terminal 10 and the second power reception terminal 11, respectively, so that the first and second power supply terminal tongue pieces 21.22 are connected to the power supply terminal tongue pieces 21.22. A high frequency power source is connected to the internal electrode 3 and the external electrode 6 through the covered cord.

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

Further, since high frequency power is supplied to the internal electrode 3 and the external electrode 6 through the first power receiving terminal 10 and the second power receiving terminal 11, glow discharge is generated between the internal electrode 3 and the external electrode 6 within the bulb 2. Ru.

This glow discharge excites the phosphor coating 5 and prompts it to emit light, which is emitted to the outside through the slit portion 8. Therefore, in addition to the bulb 2 being originally thin, the slit portion 8 provides an even narrower band of light, making this discharge lamp 1 suitable for indicating a display scale as a guide. Moreover, since it shines by itself, there is no need for any other special light source.

The lamp holder 2o is fixed to a pointer shaft 25, and when the pointer shaft 25 rotates, the lamp holder 2o is also rotated together, so that the discharge lamp 1 attached to the lamp holder 2 is also rotated together. Since it is rotated and moved to a position according to the display, a predetermined scale can be indicated.

In this embodiment, the first power receiving terminal 1o and the second power receiving terminal 11 are formed of metal caps and rings made of phosphor bronze, etc., and are placed over the bulb 2 and connected to the internal electrode 3 and the external electrode 6, respectively. When attaching and removing the lamp 1 from the lamp holder 2o, there is no need to worry about the first power receiving terminal 1o and the second power receiving terminal 11 coming off even if they rub against the first power feeding terminal tongue piece 21 and the second power feeding terminal tongue piece 22. There isn't. Therefore, electrical connection is reliably maintained.

In addition, the metal cap and ring are easy to mold, do not require much effort to manufacture, and are easy to install because they simply need to be placed over the valve 2.

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

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

Alternatively, it may be made by JR, in which the internal electrodes 3 are provided at both ends of the bulb 2.

Then, a second power receiving terminal 1 formed of a metal ring
The conductive part to which 1 is connected is not limited to the external electrode 6, but may also function as a lead wire connected to a nearby conductor or another current-carrying part. This method can be applied to any conductive part that is connected to an external power supply terminal.

Further, the electrode is not limited to a cold cathode type, but may be a hot cathode type, and at least one of xenon, krypton, neon, argon, etc., or mercury may be sealed inside.

[Effects of the Invention] As explained above, according to the present invention, the power receiving terminal of the conductive part made of a film obtained by firing a conductive base is made of a conductive metal and is adhered to the bulb, so that there is no sliding contact with the power feeding terminal. It will not peel off even if it comes in contact with it, and a reliable electrical connection can be maintained.

In addition, such a power receiving terminal does not require a cumbersome firing process or the like, and is easy to attach to the valve.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is an exploded perspective view of a discharge lamp and lamp holder used as a meter pointer, FIG. 2 is a plan view, and FIG. 4 is a sectional view taken along the line -■ in FIG. 2. FIG. 1...cold cathode fluorescent lamp, 2...bulb, 3...
- Internal electrode, 4... Lead wire, 6... External electrode (conductive part made of paste film), 7... Light blocking film, 8...
... Slit portion, 10... First power receiving terminal, 11... Second power receiving terminal, 20... Lamp holder, 21... First power feeding terminal tongue piece, 22... Second Power supply terminal tongue piece.

Claims (1)

[Claims] A low-pressure discharge lamp in which a conductive part made of a fired conductive paste is provided on the outer surface of the bulb, and the conductive part is brought into contact with an external power supply terminal for electrical connection. . A low-pressure discharge lamp, characterized in that a power receiving terminal made of a conductive metal molded product is attached to the bulb, the power receiving terminal being connected to the conductive portion and being in contact with the external power supply terminal.