Abstract: A ring-shaped glass bulb includes a ring-shaped light permeable hollow body having opposite ends each disposed at a prescribed distance from one to the other, and a filament arranged in the hollow body of the bulb. The outer-most edge portion of the outer ring edge of one of the ends of the bulb is disposed at at least the intersecting point between an outer circumferential line extending from the outer-most edge portion of the outer ring edge of the other end of the bulb and a tangent line extending from the inner-most edge portion of the inner ring edge of the other end of the bulb. A desirable prescribed distance between the opposite ends of the bulb is equal to or greater than 30 mm.

Abstract: A halogen incandescent lamp performing halogen cycle in operation, comprising a bulb formed of light-transmitting material in which gas containing halogen atoms and inert gas are enclosed, a tungsten filament with working temperature of 2,800.degree. K. or more contained in the bulb, at least a pair of lead-in wires connected to or integrally formed on both ends of the tungsten filament, respectively, and having a part sealed in the bulb, the lamp characterized in that the light-transmitting material is aluminosilicate glass having a strain point of 660.degree. C. or higher and an average thermal expansion coefficient of 41.times.10.sup.-7 to 48.times.10.sup.-7 cm/cm/.degree.C. at a temperature of 100.degree. to 300.degree. C., and that at least filament-side seal portions of the lead-in wires have a diameter of 0.2 to 0.6 mm.

Abstract: Provided is a reflective lamp comprising a bulb including a front lens section and a reflective mirror section fused thereto, said front lens section consisting of glass material containing neodymium and coated on its inner surface with a first thin film reflecting infrared rays and permitting visible lights to be transmitted therethrough, said reflective mirror section consisting of glass material containing no neodymium and coated on its inner surface with a second thin film reflecting visible lights. The lamp is capable of preventing the rise in the temperature of the bulb and yet providing a sufficiently high color rendering. Further, the lamp can offer the advantage of reducing its manufacturing cost.

Abstract: A method for manufacture of lamp bulbs wherein four wires are arranged in parallel with and spaced apart by a suitable distance from each other and supported by a plurality of glass beads which are melted when the wires are attached. Two inner wires of the four wires are cut off at predetermined points and bent at cutout ends whereby lead and anchor wires are provided whereas the two outer wires are bent to form frame wires, whereby a filament-supporting assembly is provided; thereafter filaments are supported between the lead wires of the filament supporting assembly and engaged with the anchor wire; the filament-supporting assembly with the filaments supported thereon is placed into a glass envelope; the envelope is evacuated and sealed; and a base is attached to the envelope.