High-pressure discharge lamp

• US 20020084756A1
• Filed: 12/13/2001
• Published: 07/04/2002
• Est. Priority Date: 12/19/2000
• Status: Active Grant

• 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
• Granted Patent: US 6,727,650 B2
• Time in Patent Office: Days
• 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 high-pressure discharge lamp (1) with a substantially elongate bulb (1) which has two neck regions (11, 12) and a vacuumtight discharge chamber (13) in a central position, characterized in that at least one neck region (12) is provided at least partly with a reflection layer (7).

2. A high-pressure discharge lamp (1) as claimed in claim 1, characterized in that the reflection layer (7) reflects radiation in the visible and infrared spectral ranges.

3. A high-pressure discharge lamp (1) as claimed in claim 1, characterized in that the reflection layer (7) is provided on the outside of the bulb (1) in the neck region (12).

4. A high-pressure discharge lamp (1) as claimed in claim 3, characterized in that the reflection layer (7) is a dielectric interference filter or a layer of a metal material or a metal oxide.

5. A high-pressure discharge lamp (1) as claimed in claim 4, characterized in that the reflection layer (7) is provided in the neck region (12) over a width of at most 10 mm measured from the start of the bulb (1).

6. A high-pressure discharge lamp (1) as claimed in claim 4, characterized in that the dielectric interference filter is formed by an optical multilayer system comprising layers of alternating high and low refractive index, in particular made of metal oxide.

10. A projection system with a high-pressure discharge lamp (1) as claimed in any one of the claims 1 to 6 or a reflector lamp as claimed in any one of the claims 7 to 9.

7. A reflector lamp with a reflector (2) and a high-pressure discharge lamp (1) arranged in the reflector (2) along the optical axis (4) and having a substantially elongate bulb (1) which has two neck regions (11, 12) and a vacuumtight discharge chamber (13) in a central position, characterized in that the neck region (12) facing the reflector opening is at least partly provided with a reflection layer (7).

8. A reflector lamp as claimed in claim 7, characterized in that a cold-light mirror is arranged on the inside of the reflector (2), and the reflection layer (7) is formed by a metal oxide, in particular of zirconium oxide, or a dielectric interference filter.

9. A reflector lamp as claimed in claim 7, characterized in that a metal reflector layer (3) is arranged on the inside of the reflector (2), and in that the reflection layer (7) is made of a metal material, in particular of aluminum, or is a dielectric interference filter.