Abstract: A low-pressure mercury vapor discharge lamp has a light-transmitting discharge vessel enclosing, in a gastight manner, a discharge space provided with a filling of mercury and a rare gas. The discharge vessel includes electrode(s) for maintaining a discharge in the discharge space. The discharge vessel further includes a dispenser for controllably dispensing hydrogen into the discharge space during lamp operation. The hydrogen gas pressure during lamp operation is in the range between 10?3 Pa and 10 Pa.

Abstract: A low-pressure mercury vapor discharge lamp has a light-transmitting discharge vessel (10) enclosing, in a gastight manner, a discharge space (11) provided with a filling of mercury and a rare gas. The discharge vessel (10) comprises discharge means for maintaining a discharge in the discharge space (13). At least a part of an inner wall (12) of the discharge vessel (10) is provided with a protective layer (16). The discharge vessel (10) is provided with a luminescent layer (17) comprising a luminescent material. The luminescent layer (17) further comprises inorganic softening particles (27) with a softening point above 450° C. The size of the softening particles (27) is in the range from 0.01 to 10 gm. Preferably, the softening particles (27) are selected from the group formed by strontium borate, barium borate, yttrium borate, yttrium-strontium borate and calcium pyrophosphate.

Abstract: A low-pressure mercury vapor discharge lamp (1) has a discharge vessel (3) enclosing, in a gastight manner, a discharge space provided with a filling of mercury and a rare gas. The discharge vessel (3) comprises means for maintaining an electric discharge in the discharge space. A portion of the surface (15) of the discharge vessel (3) facing the discharge space is provided with a protective layer (16) comprising yttrium oxide or aluminum oxide and further comprises a borate and/or a phosphate of an alkaline earth metal and/or of scandium, yttrium, or a further rare earth metal. Preferably, the alkaline earth metal is calcium, strontium, and/or barium. Preferably, the further rare earth metal is lanthanum, cerium, and/or gadolinium. The lamp according to the invention has a comparatively low mercury consumption.

Abstract: The low-pressure mercury vapor discharge lamp has a light-transmitting discharge vessel (2) enclosing, in a gastight manner, a discharge space (1) provided with a filling of mercury and a rare gas. The discharge vessel comprises discharge means (8) for maintaining a discharge in the discharge space (1). The discharge vessel comprises dispenser means (20) for controllably dispensing hydrogen into the discharge space. The hydrogen gas pressure is in the range between 10?3 Pa and 10 Pa. Preferably, the hydrogen gas pressure is in the range between 10?2 Pa and 1 Pa. A low-pressure mercury vapor discharge lamp with a good maintenance is obtained.

Abstract: A low-pressure mercury vapor discharge lamp has a light-transmitting discharge vessel (10) enclosing, in a gastight manner, a discharge space (11) provided with a filling of mercury and a rare gas. The discharge vessel (10) comprises discharge means for maintaining a discharge in the discharge space (13). At least a part of an inner wall (12) of the discharge vessel (10) is provided with a protective layer (16). The discharge vessel (10) is provided with a luminescent layer (17) comprising a luminescent material. The luminescent layer (17) further comprises inorganic softening particles (27) with a softening point above 450° C. The size of the softening particles (27) is in the range from 0.01 to 10 gm. Preferably, the softening particles (27) are selected from the group formed by strontium borate, barium borate, yttrium borate, yttrium-strontium borate and calcium pyrophosphate.

Abstract: Low-pressure mercury vapor discharge lamp has an at least partly substantially cylindrical discharge vessel (10) with a length Ldv and with an internal diameter Din. The discharge vessel (10) encloses, in a gastight manner, a discharge space (13) provided with a inert gas mixture and with mercury. The discharge vessel (10) comprises discharge means (electrodes 20a; 20b) for maintaining a discharge in the discharge space (13). According to the invention, the ratio of the weight of mercury mHg in the discharge vessel (10) to the product of the internal diameterDin and the length of the discharge vessel Ldv is given by the relation: wherein C (0.01 (g/mm2. Preferably, 0.0005 (C(0.005(g/mm2. Preferably, the discharge vessel (10) contains less than 0.1 mg mercury. The discharge lamp according to the invention operates under unsaturated mercury conditions.

Abstract: A low-pressure mercury vapor discharge lamp is provided with a light-transmitting discharge vessel, enclosing, in a gastight manner, a discharge space provided with a filling of mercury and a rare gas. The discharge vessel comprises means for maintaining a discharge in the discharge space. At least a portion of an inner wall of the discharge vessel is provided with a translucent layer which-according to the invention has a thickness in the range from 1 to 50 ?m and comprises an alkaline-earth-borate.

Abstract: The electric lamp comprises a lamp vessel (1) which is transparent to visible light and which accommodates a light source. At least a part of the lamp vessel (1) is covered with a light-absorbing coating (3). According to the invention, the light-absorbing coating (3) comprises a network which can be obtained by conversion of an organically modified silane by a sol-gel process. The organically modified silane is selected from the group formed by compounds of structural formula R′Si(OR″)3, wherein R′ is an alkyl or aryl group and R″ is an alkyl group. Preferably, R′ is CH3 or C6H5 and R″ is CH3 or C2H5. Nano-sized silica particles having a diameter d≦50 nm may be incorporated in the network. The pigment is preferably chosen from the group formed by Fe2O3, P-doped Fe2O3, ZnFe2O4, ZnO.Fe2O4, CoAl2O4, Nd2O5, BiVO4 and zirconium praseodymium silicate or mixtures thereof.

Abstract: The low-pressure mercury vapor discharge lamp has a filling of mercury and an inert gas, and the glass discharge vessel (1) is provided on the inner surface (4) of the wall (3) with a film (6) of trifluoride and/or oxyfluoride of at least one element, which is trivalent at most, which is selected from lanthanides, lanthanum, scandium and yttrium. The film (6) counteracts transport of mercury from the discharge vessel to the wall (3) and of alkali from the wall (3) to the discharge vessel. In this manner, a decrease of the lamp's efficiency and of the service life are counteracted.