High pressure discharge lamp with reflection layer on the neck portion

• US 6,727,650 B2
• Filed: 12/13/2001
• Issued: 04/27/2004
• Est. Priority Date: 12/19/2000
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Moench, Holger, Ritz, Arnd, Klinkenberg, Klaus
• Primary Examiner(s): Patel, Nimeshkumar D.
• Assistant Examiner(s): Guharay, Karabi
• Application Number:
  US10/022,169
• Publication Number:
  US 20020084756A1
• Time in Patent Office: 866 Days
• Field of Search: 313/635, 313/634, 313/571, 313/572, 313/573, 313/489, 313/110, 313/113, 313/114, 313/112
• US Class Current: 313/635
• CPC Class Codes: G03B 21/2026 Gas discharge type light sources, e.g. arcs
• CPC Class Codes: H01J 61/35 provided with coatings on the walls thereof; Selection of materials for the coatings using coloured coatings H01J61/40; using luminescent coatings H01J61/42
• CPC Class Codes: H01J 61/523 Heating or cooling particular parts of the lamp
• CPC Class Codes: H01J 61/86 with discharge additionally constricted by close spacing of electrodes, e.g. for optical projection

Abstract

The invention relates to a high-pressure discharge lamp with a substantially elongate bulb which has two neck regions and a vacuumtight discharge chamber in a central position. The invention further relates to a reflector lamp and a projection system comprising such a high-pressure discharge lamp. A disadvantage of known lamps is formed by the too high temperatures of critical components. According to the invention, therefore, it is suggested that the high-pressure discharge lamp is provided at least partly with a reflection layer at least in a neck region. The reflection layer reflects radiation in the entire spectrum (ultraviolet, visible, infrared) and is used in particular as a heat shield layer which reflects the radiation incident on the neck region at the lamp end and acting as heat radiation, so that an additional heating is prevented or at least reduced.

Claims

1. A reflector lamp with a reflector having an opening and a high pressure discharge lamp arranged in the reflector along the optical axis and having a substantially elongate bulb which has two neck regions and a vacuum tight discharge chamber in a central position, characterized in that one of the neck regions faces the reflector opening and is provided with a reflection layer which extends over a width of at most 10 mm measured from the start of the bulb, wherein there is a reflecting means on the inside of the reflector which is selected from the group of a cold light mirror and a metal reflector layer and wherein if the reflecting means is a cold light mirror said reflection layer is formed by a metal oxide and if the reflecting means is a metal reflector layer said reflection layer is made of aluminum.