JPS5871554A - Discharge lamp - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to discharge lamps.

The present invention comprises a fire-resistant transparent envelope containing a gas and/or vapor fill and a pair of electrodes between which an electric discharge occurs during operation of the lamp, through a so-called ribbon encapsulation of the envelope. The present invention relates to a type of discharge lamp in which current is sent to the electrodes from the outside. The enclosure comprises a piece of refractory metal foil, usually molybdenum, to each end of which is attached an electrode support and conductor, connecting the foil and the electrode (or support). The adjacent base and conductor wires are embedded in the envelope (usually made of silica) such that the electrodes are within the envelope and the conductors extend outside the envelope. The foil strip thus forms part of a compact conductor assembly for carrying current to the electrodes, and at the same time is easily attached to the silica to provide an effective encapsulation.

The invention is particularly applicable to short arc discharge lamps such as those used for movie and television lighting, flood and stadium lighting, and for photochemical reactions.

Two basic configurations are currently used for short arc high pressure discharge lamps having fused silica envelopes.

These configurations include double-ended lamps in which the nine foil encapsulations associated with the two electrodes are located at opposite ends of the envelope, and single-ended lamps in which the two foil encapsulations are located at the same end of the envelope. be.

In the case of double lamps, the encapsulation is usually formed by flattening or narrowing the foil strip and the electrode mate onto the adjacent ends of the support and the associated conductor, i.e. by the tubular part of the outer envelope from which the assembly extends. . Single-ended lamps are usually formed by a narrow, flat enclosure.

It is an object of the invention to provide an alternative type of encapsulation arrangement which has advantages over the current types of lamps mentioned above, as will become clear from the description below.

According to the invention, in a high-pressure discharge lamp of the type mentioned above,
The lamp envelope is formed with an integral projection having an inner encapsulant member and a tubular outer encapsulant member surrounding and enclosed by the inner member, and a conductor assembly associated with both electrodes is formed. Enclosed between the inner and outer members.

The inner and outer encapsulation members are preferably circular in cross-section, but any convenient cross-sectional shape may be used as desired.

In forming said enclosure, the tubular outer material is conveniently collapsed onto the inner member in a suitable non-oxidizing atmosphere, and the conductor assembly is suitably supported therebetween, preferably in diametrically opposed positions. .

The foil strips used are preferably molybdenum, such as those used in conventional ribbon encapsulations.

The lamp according to the invention eliminates many of the disadvantages encountered in single-ended double-ended double-ended high-pressure discharge lamps and also eliminates the drawbacks of the known narrow type of enclosure used in current types of single-ended lamps. Exclude.

Because the lamp is single-ended, it therefore requires one cut in the associated reflector, thus reducing the front gain from the reflector when towing compared to the two cuts required for a repeating lamp. Increase direction light.

Furthermore, the lamp can be positioned by gripping at only one point, which eliminates the stresses in the silica that are often encountered when gripping repeating lamps in two positions.

Furthermore, when the conductor assemblies are encapsulated via the protrusions in diametrically opposed locations, the tracking distance between the electrical bridges inside the rung envelope is approximately equal to one-half of the outer circumference of the inner encapsulation member, so that the configuration It is more suitable for use with high voltage pulses required for starting and restarting than current single-ended lamps with enclosures.

The encapsulation of the lamp according to the invention can easily be several millimeters or as long as required, so that the mold section of the encapsulation remote from the arc can be damaged by oxidation of the foil strip or the associated conductor. Ensure that the temperature is cool enough to prevent

Additionally, the bulbous portion of the outer envelope containing the gas and/or vapor filler can be substantially spherical, which is the strongest shape to withstand the high pressures generated within the bulbous portion during operation. This eliminates potential weak spots along the top of the flat narrow encapsulation and also reduces the cold spot temperature by configuring the inner surface of the bulb to be symmetrical about the axis between the electrode tips. Thus allowing the lamp to rotate around the length of the arc without significantly changing the color or radiation from the lamp.

Lamp configurations according to the invention are compatible with a wide range of lamp sizes from a few watts to many kilowatts.

The filler may for example consist of mercury with an inert starting gas or mixture of gases such as argon or one or more gases.
It may consist of a metal halogenide and one or more inert starting gases with or without mercury.

The lamp according to the invention has the further advantage that it is easy to install and therefore the arc is at right angles to the long axis of the reflector. This allows for the design of efficient reflectors for use with lamps while the foil strips of the encapsulation lie in a plane parallel to the main light beam to minimize heat absorbed by the foil strips from the reflected beam.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

11, 1b and 1C, the lamp has a substantially spherical thick-walled bulb 1 of transparent fused silica with a hollow cylindrical projection extending from and integral with the bulb. It is equipped with an outer envelope Et comprising 2. The lamp has a pair of refractory metal, e.g. tungsten, electrodes in the form of short rods, each electrode parallel to the axis of the projection 2 and at their outer end touching the wall of the silica bulb. are enclosed within the wall of the cylindrical protrusion 2 at diametrically opposed positions as shown in the drawings.

A ribbon 4 of molybdenum corrosion foil is brazed to the outer end of each electrode 3 [the ribbon extends longitudinally within the wall of the protrusion and has a molybdenum conductor @ 5 if filled at its outer end].
The molybdenum conductive wire is also enclosed in the wall of the projection 2 at its end, and the opposite end of the conductor projects axially from the projection.

The outer envelope contains a large amount of mercury 8 and one or more metal halides, and the filler material is introduced through the pumping stem, which is then encapsulated as in 6.

The lamp configuration described above is suitable for lamps used in cinematography, one such lamp having an arc length of 12t.
ig, bulb volume &5- and the power consumption is 1200W.

When manufacturing such a lamp, as shown in FIG. 2, the electrode 5 is inserted into the round spherical shape s1, which has an outer hollow cylindrical extension tube 9t protruding from the pumping stem 7 and the opposite end thereof. Ru. The fused silica inner encapsulation tube 10, which is closed at one end, is mounted coaxially within the extension tube 9 with its closed end furthest back, and thus has a molybdenum ribbon 4.
The outer ends of the two electrodes 3 and the adjacent ends of each conductor II5 are connected to the encapsulating tube 1.
0 and the extension tube 90 to face each other in the diametrical direction. The extension tube 9 is then heated above its softening temperature and collapsed onto the ribbon 4 and the adjacent ends of the electrode 3 and conductor Is5 in a non-oxidizing atmosphere to form a ribbon enclosure as shown in FIG.

Next, the spherical part is evacuated through the pumping stem 7t and filled with a suitable filling material, which is then crushed near the spherical part of the pumping stem 7m to remove the excess part and finally encapsulated. .

The outer surface 10a of the closed inner end of the encapsulating tube 10 is suitably shaped to be a substantially smooth continuation of the spherical inner surface of the spherical portion.

However, as will be described later, other shapes may be used as desired.

It is conveniently suitable for use with a cap 11 of heat-resistant insulation in the form of a lamp collar, for example a suitable ceramic, which collar fits coaxially around the projection 2 as shown in FIG. The protrusion is then encapsulated with a suitable capping adhesive 12. A free conductor like 1S is conductor 5
It is convenient to solder ti. The lamp is disposed to be supported within the opening in the base plate 14 and is held in place by a spring clip 15. The base plate 14, together with the outwardly facing flange 16 on the cap, protects from the high temperatures generated in the arc over the encapsulation of the protruding s-shaped section remote from the arc.

As mentioned above, the inside of the bulb does not have to be perfectly spherical; for example, it can be modified to create an entirely "isothermal bulb" to equalize the internal temperature when the lamp operates in one fixed operating position. Good too.

This allows the use of metal nohalides with high vapor pressures, thus changing the color of the lamp's radiation. FIG. 5 shows an example of different bulb shapes, the bulbs in FIGS. 5a and 5b being modified by providing differently shaped bulbs 1101 in the inner encapsulating tube 10, so that two mutually perpendicular bulbs of the same lamp can be used. The bulb in FIG. 5C, which shows a cross-sectional view, has been modified by using a different bulb shape.

If desired, a solid silica lot as shown in FIG.

17 may be used instead of the hollow inner tube 100. tx
The pressure within the lamp bulb may be varied by the provision of a reflector, which may be made of a suitable reflective material as shown in FIG. The spherical portion as shown in Figure 7b may be coated with a reflective coating 19M of zirconia, titania, or other suitable material. A similar reflective coating 19bt may be painted on the inside of the inner envelope tube at the end adjacent the lamp envelope.

The nine lamp embodiments shown so far have an encapsulation having a foil strip 4 associated with each electrode 5 to carry a current t of the skin.

However, this arrangement may not be suitable for very high current lamps, for example 30 amperes or more, so a large number of encapsulating foil pieces and conductors 5 may be used. FIG. 8 shows one such lamp, with each electrode 3 (only one shown)
are connected to each conducting wire 5a and to a pair of foil pieces 4a.

As shown in FIG. 10, grooves 20t may be formed in the silica-filled tubes 9 and 10 parallel to their axes, into which a separating insulator (not shown) of, for example, mica may be inserted to By increasing the tracking distance, the height of the voltage pulse that can be used for example for starting may be increased.

As shown in Fig. 9, the enclosing tube 9
．． The shape of the enclosure itself may be changed by increasing the diameter of 10. Such an arrangement increases the distance between conductors and is suitable for allowing the use of very high voltages for hot restart of small lamps, such as those rated for 200 W or less.

Instead of arranging the electrodes 3 parallel to each other, the electrodes can be modified by tilting the entire electrodes with respect to each other as shown in FIG. 11, or by bending the inner ends of the electrodes towards each other as shown in FIG. The tip of the arc may assist in stabilizing the arc.

The electrode 3 may consist of a simple inert tungsten rod as in the embodiment of the drawings, but an active rod with or without a coil may be used instead, with a coil holding a suitable entender.

Furthermore, although the lamp in the drawings shows the capping projection 6 diametrically opposite the upper end of the bulb, i.e. the capping projection 2, the pumping stem and therefore the capping projection 6 may be located at any other convenient location on the bulb if desired. It's okay.

[Brief explanation of the drawing]

FIG. 1a is an axial sectional view of one lamp, FIGS. 1b and 1C are elevational and plan views of this lamp, FIGS. 2 and 3 are views showing the manner in which the lamp is formed, and FIGS. 4
The figure shows the lamps installed on plywood.The lamps shown in Figures 1 to 3 are mounted on plywood, and the lamps shown in Figures 5 to 9.
FIG. 12 shows various modifications of the lamp configuration. In the figure, E: Outer envelope, 1: Spherical portion, 2: Cylindrical protrusion, S: Electrode, 4: Metal foil piece ribbon, 5:
... Conductor wire, 6... Encapsulating projection, 7... Bo/B/G stem, 8... Mercury, 9... Outer extension tube, 10... Inner enclosing tube Patent applicant's agent Mei 1) Nobuyuki ;'
FIG, JinFIc fan r+c1b
Mouth c? ! - "+c, 3 Procedural amendment (C method)) January 1st, 1980, Director General of the Japan Patent Office Aio Wakasugi (1) Indication of Case No. 128293 (2) Name of Invention Discharge Lamp (3) Amendment Relationship with the case of the person who is responsible for the patent The name of the person for patent purposes The General Electric Link Company. P, L, C. 4 Agent postal code 100

Claims (1)

[Scope of Claims] t. A fire-resistant translucent spherical portion <1) terminating one end of the outer extension tube (9) and adjacent to the spherical portion within the outer extension tube (9). At the end of the above outer extension tube (9) t-
A gas discharge between the inner tube of refractory material forming the lamp outer envelope (1) together with the spherical portion and the electrodes protruding from the other end and each trapped within the outer envelope is prevented. In the discharge lamp, the inner envelope tube a and the outer extension tube (9) are connected to each other and the conductor (5),
The above-mentioned discharge rung is characterized in that the tube is enclosed in a foil piece (4) and an electrode (3). 2. The discharge lamp according to claim 1, characterized in that the inner envelope tube QQ is in the form of a tube closed at the end adjacent to the lamp outer envelope (1). discharge lamp. (v) The discharge lamp according to claim 1't or 2, characterized in that the lamp envelope (2) is elongated along an axis defined by the tip of the electrode (3). Discharge lamp above. The discharge lamp according to any of the claims, characterized in that a region of the lamp envelope adjacent to the outer extension tube (9) is provided with a reflective coating (8b, 19m, 19b). discharge lamp. 5. The discharge lamp according to any of the claims, characterized in that the surface (10!l) of the inner envelope tube αω forming a part of the inner surface of the lamp envelope is substantially flat. Discharge lamp above. 6. The discharge lamp according to any one of the claims, characterized in that the surface (1011) of the inner sealed tube part forming a part of the inner surface of the lamp outer envelope is convex. 2. The discharge lamp according to claim 2, characterized in that a reflective coating (9b) is provided on the inside of the inner sealed tube portion at the end adjacent to the lamp outer envelope (1). lamp. a) characterized in that it comprises a reflector in the form of a cup-shaped boxwood (18 m) fitting coaxially around the discharge lamp according to any of the preceding claims and said outer extension tube (9); and light. 9 a bulbous part (1) with an outer extension tube (9) and a pumping stem (7) and a slack t in said outer extension tube (9);
- a method for manufacturing a discharge lamp from an inner-side encapsulation tube a adapted to fit together and a pair of electrodes (3) comprising a piece of refractory metal foil (4) for conducting current; The enclosure tube α is held within the outer extension tube (9), and the electric bridge (3) and foil piece (4) are suspended in the gap between the outer extension tube and the inner enclosure tube, so that the An electrode extends into said bulbous portion (1), said outer extension (9) being heated in a non-oxidizing atmosphere and collapsed onto said foil ribbon and the adjacent end of said electrode to form a ribbon encapsulation. The above method is characterized by forming. 1α Claim 1 provides a discharge lamp according to claim 2, in which the conductor assembly of each electrode comprises a plurality of current-carrying foil pieces adapted to be connected in parallel. The above discharge lamp is characterized by: 11. The discharge lamp according to claim 1 or 2, wherein the distance between the metal foil pieces is larger than the distance between the tips of the electrodes.