Welch Allyn, Inc.

Timothy W Graham

Daniel C Briggs

Brian J Thomas

John W Sims

Douglas M Rutan

John Scoins

Diane M Salvati

A high performance miniature projection lamp which includes a glass envelope having a pair of opposite neck portions each with a coaxial central opening having a reduced section and an hermetically sealed central chamber having a volume of about 130 mm.sup.3 which contains a fill. The fill includes an argon pressure at room temperature at a range of about 0.5 atmospheres to about 2.0 atmospheres and mercury in an amount in the range of about 5 mg to about 15 mg, and a mixture of metal halide material in an amount from about 50 up to 1000 micrograms. A pair of axially aligned electrodes are positioned at opposite neck portions and separated form each other by a predetermined distance. The electrodes each have a shank portion which each having a coil wrapped around its end.

Miniature projection lamp

A low power metal halide discharge lamp having an improved electrode structure. Two elongated electrodes fabricated of a doped tungsten each extend axially through a respective neck of a bulb into an arc chamber. Each of electrode comprises a lead-in wire having a diameter ranging between about 0.003 to 0.018 inches that enters the arc chamber. A post member is mounted on the lead-in wire, out of contact with the associated neck, and is preferably welded to the lead-in. The post member has a flat distal surface for transferring heat to vapors in said arc chamber. It is larger in diameter than its associated lead-in wire, and has a diameter in a range of 0.005 to 0.040 inches. The flat distal surfaces of the two post members face one another in spaced apart relationship, the space therebetween forming an arc gap. In operation the distal surfaces of the post members have relatively large areas in contact with vapors in the arc chamber for heat transfer, and the heat is sufficiently dispersed in the distal region of the post members to prevent burn back.

Electrode for metal halide discharge lamp

Apparatus and a method for combining radiant energy of substantially distinct spectral bands to produce a light source having predetermined color temperature or chromaticity characteristics. The apparatus includes a generating source that generates emissions of radiant energy from at least two spatial emission regions. Each of the spatial emission regions emits radiant energy in a substantially distinct spectral band. The apparatus further includes an optical directing system that directs a substantial portion of the radiant energy emitted from the emission regions. The optical directing system includes a positioning region that contains a near focus and a combining region that contains a far focus. The generating source is supported substantially within the positioning region of the optical directing system such that the radiant energy, emitted from the spatial emission regions, is substantially directed to the far focus and combined within the combining region to produce an effective light source having predetermined color temperature or chromaticity characteristics.

Light source having desired color temperature and chromaticity

A metal halide arc discharge lamp is disclosed having a power input rating of not more than 35 watts. The lamp includes an envelope of light transmissive material, such as fused quartz, including a bulb portion, a pair of transitional neck portions extending from the bulb portion, and a pair of stem portions extending from the transitional neck portions respectively. The bulb portion of the envelope defines an arc chamber therein and has an external surface area of such value as to produce a wall loading not exceeding 35 watts/cm.sup.2. The arc chamber contains a fill of mercury, inert gas and metal halide. The mercury and the metal halide are adapted to substantially vaporize during operation of the lamp. A pair of electrodes extend into the arc chamber from the pair of neck portions respectively. Each electrode has an electrode tip spaced apart from one another by a distance A within the arc chamber. The neck portions of the envelope each have a wall surrounding a segment of one of the electrodes. The walls of the neck portions each have a stretched section with a minimum wall thickness not exceeding about 1.5 mm. A pair of inlead assemblies are electrically coupled to the pair of electrodes respectively. The inlead assemblies pass from the electrodes through a hermetically sealed section in the stem portions of the envelope to the exterior of the lamp.

Low watt metal halide lamp

A low-wattage metal-halide discharge lamp has a tube of the double ended type that forms a bulb or envelope, a pair of electrodes, e.g., an anode and a cathode, which penetrate into an arc chamber inside the envelope, and a suitable amount of mercury plus one or more metal halide salts. The electrodes are each formed of a refractory metal, i.e., tungsten wire, extending through the respective necks into the arc chamber. The electrodes are of a composite design i.e., in the form of a club, with a lead-in wire of small diameter supported in the associated neck, and a post member of greater diameter supported on the lead-end wire. The post members are supported of contact with the necks and also out of contact with the bulb wall. The larger size of the post member allows heat at the tip to diffuse back into the post member, so that the metal tip will not evaporate. The narrow lead-in wire keeps most of the heat in the bulb, so that flow of heat out of the neck portions is limited. Lamps of this design achieve high efficacy at relative low power (below 30 watts).

Apparatus and a method for combining radiant energy of substantially distinct spectral bands to produce a light source having predetermined color temperature or chromaticity characteristics. The apparatus comprises a generating source that generates emissions of radiant energy from at least two spatial emission regions. Each of the spatial emission regions emits radiant energy in a substantially distinct spectral band. The apparatus further comprises an optical directing system that directs a substantial portion of the radiant energy emitted from the emission regions. The optical directing system includes a positioning region that contains a near focus and a combining region that contains a far focus. The generating source is supported substantially within the positioning region of the optical directing system such that the radiant energy, emitted from the spatial emission regions, is substantially directed to the far focus and combined within the combining region to produce an effective light source having predetermined color temperature or chromaticity characteristics.

Growing community of inventors

Union Springs, NY, United States of America

Timothy W Graham