Electric incandescent lamp.

摘要

The electric incandescent lamp according to the invention has a lamp vessel (1) comprising a second wall portion (6) opposite to a neck-shaped first wall portion (4). Between the largest diameter (3) and the second wall portion (6) is disposed a third mirror-coated wall portion (7,7 min ), which is mainly curved in axial section along the arc of a circle, whose centre (8,8 min ) is located on the other side of the axis of symmetry (2) and of the largest diameter (3). The filament (10) has a plane of symmetry passing through the axis of symmetry (2) and extends on either side of a second plane through said axis at right angles to the first plane. The lamp produces together with an external reflector a narrow beam with a high luminous flux at the centre thereof.