LED illumination device for fluorescent light fixture

摘要

An LED illumination device that can be mounted between a pair of sockets provided to a fluorescent light fixture is provided with a first power source circuit that illuminates an LED using DC power obtained by converting and rectifying AC power supplied from the sockets, and a second power source circuit that illuminates the LED using an internal battery. An IC chip installed in the illumination device detects a first current conduction state in two AC power lines that supply the AC power necessary to drive the first power supply circuit and a second current conduction state in another AC power line, and, on the basis thereof, determines whether the device is in a normal illumination mode, a normal off mode, or an emergency illumination mode. On the basis of the determination results, the LED illumination device is controlled according to the mode. When in the emergency illumination mode, the LED is illuminated by the second power source circuit, and the LED illumination device functions as an emergency light.

主权项

1. An LED illumination device fittable between a pair of sockets already provided for a fluorescent lamp, comprising:
(i) a first power supply circuit that illuminates LED's by using a DC power obtained by converting and rectifying an AC power supplied from the sockets, (ii) a second power supply circuit that illuminates the LED's by using an internal battery, and (iii) a controller that controls switching of illumination modes during normal illumination operation to be done while a light switch is being ON, the illumination mode being switched between a first illumination mode wherein said first power supply circuit lightens the LED's at a first predetermined intensity of illumination and charges the battery and a second illumination mode wherein said second power supply circuit lightens the LED's at a second predetermined intensity of illumination that is lower than said first predetermined intensity of illumination, (iv) said controller further operating to control such that, in an emergency wherein the AC power supply is interrupted, said second power supply circuit lightens the LED's, (v) said controller controlling switching of said first and second illumination modes such that said first illumination mode is switched to said second illumination mode in response to detection of a residual amount of the internal battery reaching a predetermined upper threshold, wherein said second illumination mode is switched to said first illumination mode in response to detection of the residual amount of the internal battery reaching a predetermined lower threshold; (vi) said controller executing a light-decreasing control when the residual amount of the internal battery increases to a level approximate to said upper threshold during operation in said first illumination mode, wherein an intensity of illumination of the LED's is gradually decreased from said first predetermined intensity of illumination to be substantially equal to said second predetermined intensity of illumination; (vii) said controller further executing a light-increasing control when the second illumination mode is switched to said first illumination mode, wherein an intensity of illumination of the LED's is gradually increased from said second predetermined intensity of illumination to be substantially equal to said first predetermined intensity of illumination.