Discharge Lamp Lighting Device, and Lighting Equipment and Lighting System Using the Device

• US 20080030143A1
• Filed: 09/16/2005
• Published: 02/07/2008
• Est. Priority Date: 10/26/2004
• Status: Active Grant

• Current Assignee: Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Works Ltd (Panasonic Holdings Corporation)
• Inventors: Goriki, Takeshi, Fukuda, Kenichi, Fukumori, Noriyuki, Noro, Koji
• Granted Patent: US 7,557,523 B2
• Time in Patent Office: Days
• US Class Current: 315/209R
• CPC Class Codes: G01R 31/24 Testing of discharge tubes during manufacture H01J9/42
• CPC Class Codes: G01R 31/64 Testing of capacitors
• CPC Class Codes: H02M 7/48 using discharge tubes with control electrode or semiconductor devices with control electrode
• CPC Class Codes: H05B 41/2886 comprising a controllable preconditioner, e.g. a booster
• CPC Class Codes: H05B 41/2923 against abnormal power supply conditions
• CPC Class Codes: H05B 41/2926 against internal abnormal circuit conditions
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A level shift IC (3b) of a power supply/shutoff section (3) is operable, when a shutoff signal (Sa) is input from a timer circuit (8) for a time T during an ON state of a discharge lamp (7), to turn off a MOSFET (3a) so as to shut off power supply to a smoothing capacitor (4). When a detection signal (Sb) of a capacitor voltage is lowered to a value less than a reference voltage Vr1 during input of the shutoff signal (Sa), an output of a comparator (10) is changed from an H level to an L level in an inverted manner. In conjunction with this change, respective outputs of an auxiliary control circuit (12) and a NOT element (12a, 12b) are changed from an L level to an H level in an inverted manner. As a result, a current flows from the NOT element (12a) to an LED (13b) through a resistor (13a) to turn on the LED (13b). Thus, a life end of the smoothing capacitor 4 is annunciated, and a main control circuit (6) is operable to suppress an output of an inverter main circuit (5).

Claims

1. A discharge lamp lighting device comprising:

a DC power source circuit;

a smoothing capacitor connected to an output end of the DC power source circuit;

an inverter main circuit adapted to convert a DC power output from the smoothing capacitor, to an AC power, and supply the AC power to a discharge lamp;

a main control circuit adapted to control the inverter main circuit so as to control the AC power to be supplied to the discharge lamp;

a timer circuit adapted to count a predetermined time;

a power supply suppression section adapted to suppress power supply to the smoothing capacitor during a period where the timer circuit counts the predetermined time;

a voltage/voltage drop detection section adapted to detect a voltage or a voltage drop of the smoothing capacitor at least during a period where the power supply to the smoothing capacitor is suppressed;

a first comparator adapted to compare between a detection value of the voltage or the voltage drop of the smoothing capacitor and a first threshold value, and output a result of the comparison; and

an auxiliary control circuit adapted to perform a control operation depending on the output of the first comparator.

2. The discharge lamp lighting device according to claim 1, which includes an annunciator adapted to be controlled depending on the output of the first comparator by the auxiliary control circuit, in such a manner as to annunciate a life end of the smoothing capacitor to the outside.

3. The discharge lamp lighting device according to claim 1, wherein the auxiliary control circuit is operable to control an operation of the main control circuit depending on the output of the first comparator.

4. The discharge lamp lighting device according to claim 1, which further includes a discharge-lamp-voltage detection section adapted to detect a discharge lamp voltage, wherein the timer circuit is designed such that the predetermined time to be counted is changed in response to a change in a detection value of the discharge lamp voltage.

5. The discharge lamp lighting device according to claim 4, wherein the timer circuit is designed such that the predetermined time to be counted becomes shorter as the detection value of the discharge lamp voltage becomes higher.

6. The discharge lamp lighting device according to claim 2, which further includes:

a discharge-lamp-voltage detection section adapted to detect a discharge lamp voltage;

a discharge-lamp-life determination section adapted to determine a life end of the discharge lamp based on a detection value of the discharge lamp voltage;

a first additional annunciator adapted to annunciate the life end of the discharge lamp to the outside; and

a second additional annunciator adapted to annunciate the life ends of both the smooth capacitor and the discharge lamp to the outside,

wherein the auxiliary control circuit is operable to control each of said three annunciators based on the output of the first comparator and an output of the discharge-lamp-life determination section.

7. The discharge lamp lighting device according to claim 1, wherein:

the DC power source circuit includes a step-up chopper circuit; and

the power supply suppression section is operable to control a step-up operation of the step-up chopper circuit so as to suppress an output thereof to suppress the power supply to the smoothing capacitor.

8. The discharge lamp lighting device according to claim 1, which includes a discharge-lamp-voltage detection section adapted to detect a discharge lamp voltage, wherein said discharge lamp lighting device is designed such that a threshold value for use in the first comparator can be changed depending on a detection value of the discharge lamp voltage.

9. The discharge lamp lighting device according to claim 1, which is designed such that, when the first comparator compares between the detection value of the voltage of the smoothing capacitor and the first threshold value, the first threshold value becomes larger as a detection value of a discharge lamp voltage becomes higher, and, when the first comparator compares between the detection value of the voltage drop of the smoothing capacitor and the first threshold value, the first threshold value becomes smaller as the detection value of the discharge lamp voltage becomes higher.

10. The discharge lamp lighting device according to claim 1, wherein:

the timer circuit is designed to start counting the predetermined time in response to a trigger signal from an external control system; and

the auxiliary control circuit is operable to output a result of a determination on a life end of the smoothing capacitor to the external control system, depending on the output of the first comparator.

11. The discharge lamp lighting device according to claim 2, which further includes:

a second comparator adapted to compare between the detection value of the voltage or the voltage drop of the smoothing capacitor and a second threshold value, so as to output a result of the comparison; and

a third comparator adapted to compare between the detection value of the voltage or the voltage drop of the smoothing capacitor and a third threshold value, so as to output a result of the comparison,

whereby said first to third comparators can provide an output in a three-stage manner according to a decrease in the voltage of the smoothing capacitor or an increase in the voltage drop of the smoothing capacitor,

wherein the auxiliary control circuit is operable, in the first stage, to allow the annunciator to annunciate the life end of the smoothing capacitor to the outside, the auxiliary control circuit being operable, in the second stage, to control an operation of the main control circuit so as to controllably blink the discharge lamp, the auxiliary control circuit being operable, in the third stage, to control the operation of the main control circuit so as to turn off the discharge lamp.

12. An illumination apparatus equipped with the discharge lamp lighting device according to claim 1.

13. An illumination system equipped with the discharge lamp lighting device according to claim 1.