Patent ID: 6685525
Filing Date: 2004-02-03
Classification: C03B,H01J,H01K

Abstract:
A method for manufacturing a lamp comprising a bulb containing a filament and having an expanded portion and a pinch-sealed portion, the lamp manufacturing method comprising:softening a bulb communicating at one end thereof with an exhaust tube with the filament located inside the bulb; pinch-sealing the end opposite to the exhaust tube of the bulb; and forming the expanded portion by charging a protective gas from the exhaust tube, wherein by pressing dies each having a predetermined shape against the bulb, a narrowed portion is formed between the expanded portion and the pinch-sealed portion, simultaneously with the formation of the expanded portion, so that 0.5&lE;S/d&lE;1, wherein the outside diameter of the bulb is d (mm) and the outside diameter of the narrowed portion is S (mm).