Low-pressure mercury vapor discharge lamp with improved heat dissipation, and manufacturing method therefore

• US 20040121698A1
• Filed: 12/10/2003
• Published: 06/24/2004
• Est. Priority Date: 10/03/2001
• Status: Active Grant

• Current Assignee: Kenji Itaya, Takeshi Matsumura, Yoshinori Kakuno
• Original Assignee: Kenji Itaya, Takeshi Matsumura, Yoshinori Kakuno
• Inventors: Matsumura, Takeshi, Itaya, Kenji, Kakuno, Yoshinori
• Granted Patent: US 7,074,104 B2
• Time in Patent Office: Days
• US Class Current: 445/26
• CPC Class Codes: F21V 17/101 permanently, e.g. welding, gluing or riveting
• CPC Class Codes: F21V 31/03 with provision for venting for vehicle head lights F21S45/33; for vehicle rear lights F21S41/192
• CPC Class Codes: H01J 5/48 Means forming part of the tube or lamp for the purpose of supporting it
• CPC Class Codes: H01J 5/50 Means forming part of the tube or lamps for the purpose of providing electrical connection to it
• CPC Class Codes: H01J 9/247 specially adapted for gas-discharge lamps

Abstract

A bulb-type fluorescent lamp has a case having an open end portion for housing a lighting circuit therein, an arc tube extending outside through the open end portion of the case, and a globe having an open end portion for housing the arc tube therein. An adhesive is supplied to the inner surface of the open end portion of the case at four circumferentially spaced areas, and the open end portion of the globe is inserted into the open end portion of the case. As a result, the globe is fixed to the case with the adhesive.

Claims

1. A low-pressure mercury vapor discharge lamp comprising:

an envelope formed of a case and a globe each having an open end, the case and the globe being loosely fitted together by inserting one open end into the other;

an arc tube covered by the globe; and

a lighting circuit housed in the case, wherein

the case and the globe are partially bonded to each other along a circumferential surface of where the case and the globe overlap as the result of insertion.

2. The low-pressure mercury vapor lamp of claim 1, wherein

the case and the globe are bonded to each other at a plurality of circumferentially spaced areas of the overlapping surface.

3. The low-pressure mercury vapor lamp of claim 2, wherein

the case and the globe are bonded to each other at the plurality of areas with a sticking agent.

4. The low-pressure mercury vapor lamp of claim 3, wherein

the plurality of areas are equally and circumferentially spaced.

5. The low-pressure mercury vapor lamp of claim 4, wherein

an area S of the overlapping surface of the globe and a total area Sa of the areas where the globe is bonded to the case satisfies a relation expressed by S/6≦

Sa≦

S/2.

6. The low-pressure mercury vapor lamp of claim 1, wherein

the fitting is achieved by loosely inserting the open end portion of the globe into the open end portion of the case.

7. The low-pressure mercury vapor lamp of claim 3, wherein

the case is provided with a catchment member formed on an inner surface of the open end portion, the catchment member inwardly protruding so as to catch the sticking agent.

8. A method for manufacturing a low-pressure mercury vapor lamp provided with a globe attached to a case so as to house an arc tube therein, comprising:

a sticking agent supplying step of supplying a sticking agent to the case in an area of a circumferential surface of an open end portion to be attached to the globe; and

a fitting step of loosely fitting together an open end portion of the globe and the open end portion of the case so that the globe overlaps the area of the case where the sticking agent is supplied.

9. The method for manufacturing a low-pressure mercury vapor lamp of claim 8, wherein

the sticking agent supplying step supplies the sticking agent through a plurality of supply nozzles to a plurality of circumferentially spaced areas of the circumferential surface of the open end portion of the case.

10. The method for manufacturing a low-pressure mercury vapor lamp of claim 9, wherein

the sticking agent supplying step supplies the sticking agent substantially simultaneously to the plurality of areas of the case through the plurality of supply nozzles.