Abrégé

In order to improve stability of a discharge lamp during a light-adjusted ON period even if the light output is lowered, a DC superposition circuit (1) superposes DC voltage on AC voltage applied to a fluorescent lamp (FL). A light adjusting signal correction circuit (K1) inputs a detection value of a DC voltage detection circuit (2) and a light adjusting signal (Vsl) from outside. If the detection value of the DC voltage detection circuit (2) is higher than a first threshold value (Vth1), a light adjusting signal (Vs0) of a level higher than a light adjusting signal (Vs1) is outputted. If the detection value of the DC voltage detection circuit (2) is lower than a second threshold value (Vth2) which is not greater than the first threshold value (Vth1), the level of the light adjusting signal to be outputted (Vs0) is reduced to the level of the inputted light adjusting signal (Vs1). According to increase/decrease of the level of the light adjusting signal (Vs0) outputted from the light adjusting signal correction circuit (K1), an inverter circuit (INV) increase/decreases the AC power supplied to the fluorescent lamp (FL) so as to adjust the fluorescent lamp (FL).

Classes IPC  ?

• H05B 41/24 - Circuits dans lesquels la lampe est alimentée par courant alternatif à haute fréquence
• H02M 7/48 - Transformation d'une puissance d'entrée en courant continu en une puissance de sortie en courant alternatif sans possibilité de réversibilité par convertisseurs statiques utilisant des tubes à décharge avec électrode de commande ou des dispositifs à semi-conducteurs avec électrode de commande
• H05B 41/38 - Commande de l'intensité de la lumière

Abrégé

An electric discharge lamp device (La) in which periods (HF1, HF2) during which it outputs a high-frequency voltage for allowing a resonance circuit to resonate and periods (FB1, FB2) during which it outputs a rectangular wave voltage are alternately repeated when it starts up an electric discharge lamp (La) and a low-frequency rectangular wave voltage is applied to the electric discharge lamp (La) through a start-up circuit (4) when the electric discharge lamp (La) is operated. The electric discharge lamp (La) comprises a start-up detecting circuit (5) for detecting start-up of the electric discharge lamp (La) for the periods (FB1, FB2) during which the rectangular wave voltage is outputted and a control circuit (3C) for stopping the high-frequency voltage or lowering the frequency of the high-frequency voltage when the start-up of the electric discharge lamp (La) is detected. The control circuit (3C) increases the number of repetitions of the periods during which the high-frequency voltage and the rectangular wave voltage are alternately outputted when the start-up of the electric discharge lamp (La) is detected when once. With this, reliable start-up capability of an electric discharge lamp device alternately generating a high-frequency voltage and a rectangular wave voltage at start-up is ensured.

Classes IPC  ?

• H05B 41/24 - Circuits dans lesquels la lampe est alimentée par courant alternatif à haute fréquence
• H05B 41/282 - Circuits dans lesquels la lampe est alimentée par une puissance obtenue à partir de courant continu au moyen d'un convertisseur, p. ex. par courant continu à haute tension utilisant des convertisseurs statiques comportant des dispositifs à semi-conducteurs

Abrégé

Upon start, a discharge lamp operation device alternately outputs a section A during which a DC/AC inverter (5) outputs a high-frequency voltage so that a start circuit (6) applies a high voltage to a high-luminance discharge lamp (7) by resonance operation and a section B during which the DC/AC converter (5) applies a low-frequency rectangular voltage or a DC voltage via the start circuit (6) to the high-luminance discharge lamp (7). The section A during which a high voltage is applied by resonance operation is set to a time sufficient for performing dielectric breakdown of the high-luminance discharge lamp at an initial aging stage. A section C for alternately outputting the high-voltage generation section A and the section B for generating a low-frequency rectangular voltage or a DC voltage is set to a time sufficient for dielectric breakdown of the high-luminance discharge lamp at the end of its service life.

Classes IPC  ?

• H05B 41/24 - Circuits dans lesquels la lampe est alimentée par courant alternatif à haute fréquence
• H05B 41/231 - Circuits dans lesquels la lampe est alimentée par courant continu ou par courant alternatif à basse fréquence, p. ex. courant alternatif à 50 Hertz n'ayant aucun commutateur de démarrage pour lampes sans électrode auxiliaire de démarrage pour lampes à haute pression

Abrégé

An electrodeless discharge lamp device comprises an induction coil for producing a high-frequency electromagnetic field when supplied with high-frequency electric power and thereby exciting the discharge gas, a pair of generally semicylindrical cores (1a, 1b) disposed generally cylindrically as a whole and wound with the induction coil, and a generally cylindrical heat conductor (2) thermally connected to the cores (1a, 1b) and used to dissipate the heat generated by the cores (1a, 1b). The outer surface of the heat conductor (2) is covered with a thin sheet spacer (3), and an elastic resin (4) is placed in the space between the cores (1a, 1b) and the heat conductor (2).

Classes IPC  ?

• H01J 65/04 - Lampes à atmosphère gazeuse portée à la luminescence par un champ électromagnétique extérieur ou par une radiation corpusculaire extérieure, p. ex. lampe indicatrice
• H05B 41/24 - Circuits dans lesquels la lampe est alimentée par courant alternatif à haute fréquence