Low-pressure mercury vapor discharge lamp

• US 4,129,802 A
• Filed: 09/06/1977
• Issued: 12/12/1978
• Est. Priority Date: 09/14/1976
• Status: Expired due to Term

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Oostvogels, Franciscus M. P., Vrenken, Louis E., VAN DER Wolf, Rein W.
• Primary Examiner(s): Demeo, Palmer C.
• Application Number:
  US05/830,650
• Time in Patent Office: 462 Days
• Field of Search: 313/492, 313/489, 313/198, 338/308
• US Class Current: 313/492
• CPC Class Codes: H01J 61/545 using an auxiliary electrode inside the vessel H01J61/542 takes precedence

Abstract

A low-pressure mercury vapor discharge lamp having an internal transmissive starting strip with two separate parts. The separation between the parts is bridged by a narrow straight or helix-shaped conductive connecting strip to bring the total resistance of the starting strip to a value between 50,000 and 150,000 ohms.

Claims

1. A tubular low-pressure mercury vapor discharge lamp which comprises a discharge tube, first and second electrodes disposed within said discharge tube in spaced relationship, a light-transmissive conductive coating disposed on the interior of said discharge tube and not connected to either electrode, and a luminescent layer disposed on at least a portion of the inner surface of said discharge tube, said conductive coating consisting of at least two parts which are axially spaced and which each have a resistance per square between 400 and 4000 ohm, said parts being connected to each axially adjacent part by at least one electrical conductor having such a resistance that the total series resistance of the entire conductive coating is between 5000 and 500,000 ohms.

2. A low-pressure vapor discharge lamp as claimed in claim 1 wherein said electrical conductor consists of the same material as said parts of the light-transmissive conductive coating but has a higher resistance per square than said parts.

3. A low-pressure mercury vapor discharge lamp as claimed in claim 1 wherein said connecting conductor consists of the same material and has a similar resistance per square as the parts of the conductive coating and is suitably dimensioned to produce the total resistance of between 5000 and 500,000 ohms.

4. A low-pressure mercury vapor discharge lamp as claimed in claim 1 wherein said connecting conductor consists of at least one connecting strip, extending approximately parallel to the longitudinal axis of the lamp.

5. A low-pressure mercury vapor discharge lamp as claimed in claim 1 wherein said connecting conductor is helical.