Electric lamp and discharge devices: systems – Combined load device or load device temperature modifying... – Load device and impedance
Patent
1997-01-29
2000-05-23
Wong, Don
Electric lamp and discharge devices: systems
Combined load device or load device temperature modifying...
Load device and impedance
315 56, 315291, 362260, H05B 3702
Patent
active
060669217
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to a discharge lamp lighting device suitable for use in motor vehicle headlights.
DESCRIPTION OF THE PRIOR ART
Because of their high luminance and ability to be used as point-like sources of light, metal halide lamps and other discharge lamps are being considered for use in motor vehicle headlights. Practical application of such discharge lamps is expected in the near future.
Current discharge lamp lighting devices are basically constructed as shown in FIG. 33, i.e., having a socket 54, which is connected by means of a high voltage harness 53 to the igniter 52, into which is plugged the base 56 of the discharge lamp 55. When this discharge lamp 55 is used as a vehicle headlight as shown in FIG. 34, said socket 54 is fixed at the center of a reflector 58 supported inside light unit 57. The igniter 52 is fixed at the inside (top) of the bottom wall of the light unit 57, an inverter 59 is further fixed at the outside (bottom) of the bottom wall of the light unit 57, and the igniter 52 and inverter 59 are connected by means of a high voltage harness 60.
As shown in FIG. 33, the socket 54 comprises an outside electrode 54a and a center electrode 54b. When the discharge lamp 55 is plugged into the socket 54, said outside electrode 54a contacts the outside electrode 56a formed as part of the base 56, and the center electrode 54b similarly contacts the center electrode 56b of the base 56. The discharge lamp 55 can thus be caused to discharge and light by applying to the discharge lamp 55 the high voltage pulse, typically approximately several ten kilovolts, generated by the pulse transformer 61 contained in the igniter 52.
If the power is turned on while the discharge lamp 55 is not installed with this configuration, the high voltage pulse generated by the igniter 52 is discharged between the center electrode 54b and the outside electrode 54a of the socket 54, thus possibly damaging the socket or resulting even in injury.
To resolve this problem it was proposed in, for example, Japanese patent tokkai H4-293630 (1992-293630) to provide an interlock function. While this specific patent does not describe a socket-type discharge lamp unit, the interlock function detects whether a discharge lamp is installed to the headlight unit by means of the socket securing the discharge lamp in the headlight unit contacting the discharge lamp socket of the headlight unit, and stopping the high voltage output when the discharge lamp is not installed.
The problem with this method is that a switching function must be provided in the headlight unit or mounting socket of this discharge lamp lighting device.
DISCLOSURE OF THE INVENTION
Therefore, an object of the present invention is to provide a discharge lamp lighting device whereby applying a high voltage to the headlight unit can be prevented when the discharge lamp is not connected without modifying the headlight unit or other members.
A further object of the invention is to provide a discharge lamp lighting unit suitable for use as a vehicular headlight unit while achieving a compact discharge lamp lighting device module achieving the aforementioned object.
To achieve these objects, a discharge lamp lighting device according to the present invention comprises a lamp socket for connecting a discharge lamp; a stabilizing circuit connected to a power source and outputting a voltage to the lamp socket; a starting circuit connected between the stabilizing circuit and the lamp socket, activated before the discharge lamp begins discharging to generate a high voltage required to start discharging, and deactivated after discharging begins; and a means for deactivating the starting circuit when the discharge lamp is not installed in response to the installation or non-installation of the discharge lamp to the lamp socket. Thus, the starting circuit is not activated unless a discharge lamp is installed to the lamp socket.
When starting the discharge lamp, or more specifically when starting discharge lamp discharging, the stabilizing
REFERENCES:
patent: 4350929 (1982-09-01), Katoogi
patent: 4398123 (1983-08-01), Tsuchihashi et al.
patent: 4935668 (1990-06-01), Hansler et al.
patent: 5068570 (1991-11-01), Oda et al.
patent: 5495149 (1996-02-01), Hiramatsu et al.
patent: 5500576 (1996-03-01), Russell et al.
patent: 5574335 (1996-11-01), Sun
patent: 5596247 (1997-01-01), Martich et al.
patent: 5838109 (1998-11-01), Kobayashi et al.
English Language Abstract of JP 3-179694.
English Language Abstract of JP 4-370696.
English Language Abstract of JP 3-179609.
English Language Abstract of JP 5-198203.
English Language Abstract of JP 6-44805.
English Language Abstract of JP 7-114819.
English Language Abstract of JP 7-114805.
English Language Abstract of JP 7-114806.
English Language Abstract of JP 8-64013.
English Abstract of JP H4-293630.
Hamada Hideki
Kato Nobuo
Maruyama Ryosuke
Nakamura Toshiaki
Lee Wilson
Matsushita Electric & Works Ltd.
Wong Don
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