Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
131 words
A discharge lamp lighting device, comprising hot cathode type discharge lamp means having filaments connected across an a.c. power source through current limiting means, high frequency, high voltage generating means connected in parallel with said discharge lamp means to apply a high frequency and high voltage output thereto at least at the time of initial ignition, and a parallel circuit including a capacitor and a switching element connected to one of said filaments, said switching element comprising a current controlled resistance type switching semiconductor having a break-over voltage lower than the terminal voltage of said capacitor at the initial ignition period and higher than said capacitor terminal voltage during the lamp operating reignition period, whereby the current flowing through said one filament is reduced during the lit operation of the lamp.
Claim 2
Dependent Claim
131 words
A discharge lamp lighting device, comprising hot cathode type discharge lamp means having filaments connected across an a.c. power source through current limiting means, high frequency, high voltage generating means connected in parallel with said discharge lamp means to apply a high frequency and high voltage output thereto at least at the time of initial ignition, and a parallel circuit including a capacitor and a switching element connected to one of said filaments, said switching element comprising a current controlled resistance type switching semiconductor having a break-over voltage lower than the terminal voltage of said capacitor at the initial ignition period and higher than said capacitor terminal voltage during the lamp operating reignition period, whereby the current flowing through said one filament is reduced during the lit operation of the lamp.
Claim 3
Dependent Claim
54 words
The discharge lamp lighting device of claim 1, wherein said capacitor of said parallel circuit provides an intermittent oscillation, and wherein said high frequency, high voltage generating means comprise an oscillation circuit including a series circuit of a thyristor and a non-linear inductor, and an oscillation capacitor connected in parallel with said series circuit.
Claim 4
Dependent Claim
40 words
The discharge lamp lighting device of claim 2, wherein one of the filaments of said discharge lamp means is connected in said parallel circuit and another of said filaments is connected in said oscillation circuit for increasing the preheating current.
Claim 5
Dependent Claim
67 words
The discharge lamp lighting device of claim 1, wherein said high frequency, high voltage generating means comprises in combination an oscillation circuit and an intermittent oscillation capacitor connected in series with said oscillation circuit for generating an intermittent high frequency and high voltage output at a given phase in every half cycle of said a.c. power source for sustaining a reignition operation of said discharge lamp means.
Claim 6
Dependent Claim
23 words
The discharge lamp lighting device of claim 4 wherein said capacitor of said parallel circuit is the same as said intermittent oscillation capacitor.
Claim 7
Dependent Claim
24 words
The discharge lamp lighting device of claim 1, wherein said parallel circuit further includes current regulating means for the discharging current of said capacitor.
Claim 8
Dependent Claim
25 words
The discharge lamp lighting device of claim 6, wherein said current regulating means is one of said filaments of said hot cathode discharge lamp means.
Claim 9
Dependent Claim
28 words
The discharge lamp lighting device of claim 6, wherein said current regulating means is an impedance element such as a capacitor or inductor added to said parallel circuit.
Claim 10
Dependent Claim
40 words
The discharge lamp lighting device of claim 1, wherein said parallel circuit further includes an inductance means provided with a secondary winding, and said secondary winding is connected across one of said filaments of said hot cathode discharge lamp means.
Claim 11
Dependent Claim
64 words
The discharge lamp lighting device of claim 1, wherein said filaments of said hot cathode discharge lamp means comprise a pair of filaments one filament of which is connected in said parallel circuit, and wherein said parallel circuit comprises an inductor having a secondary winding connected in parallel with the other filament of said pair of filaments of said hot cathode discharge lamp means.
Claim 12
Dependent Claim
71 words
The discharge lamp lighting device of claim 1, wherein said hot cathode discharge lamp means comprise a plurality of hot cathode discharge lamps, said parallel circuit further including inductive means having a primary winding and a secondary winding, said primary winding being connected in series with said switching element of said parallel circuit, and wherein said secondary winding is connected across one of said filaments of said hot cathode discharge lamps.
Claim 13
Dependent Claim
62 words
The discharge lamp lighting device of claim 11, wherein each of said hot cathode discharge lamps has filaments, and said inductive means has a plurality of secondary windings, each of said secondary windings being connected across one or more filaments of said hot cathode discharge lamps for supplying preheating current due to the discharging current of said capacitor in said parallel circuit.