LIGHTING DEVICE AND LUMINAIRE

• US 20120187864A1
• Filed: 01/20/2012
• Published: 07/26/2012
• Est. Priority Date: 01/21/2011
• Status: Abandoned Application

• Current Assignee: Toshiba Lighting & Technology Corporation (Toshiba Corporation)
• Original Assignee: Toshiba Lighting & Technology Corporation (Toshiba Corporation)
• Inventors: IWAI, Naoko, Kubota, Hiroshi, Kamata, Masahiko, Terasaka, Hiroshi
• Application Number:
  US13/354,826
• Publication Number:
  US 20120187864A1
• Time in Patent Office: Days
• US Class Current: 315/291
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/38 using boost topology
• CPC Class Codes: H05B 45/50 responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
• CPC Class Codes: H05B 45/59 for reducing or suppressing flicker or glow effects

Abstract

According to one embodiment, a lighting device includes a lighting circuit. The lighting circuit includes a direct-current power supply and a DC-DC converter, and lights an illumination lamp by constant-current control. An output capacitor is connected in parallel to an output end of the DC-DC converter. A capacitance of the output capacitor is set to such a value that a peak value of a pulse-like current flowing when the illumination lamp is instantaneously detached from and attached to the output end of the DC-DC converter is one or more and four or less times a load current of the illumination lamp.

Claims

1. A lighting device comprising:

a lighting circuit that includes a direct-current power supply, a DC-DC converter having an input end connected to the direct-current power supply, and an output capacitor connected in parallel to an output end of the DC-DC converter, and lights an illumination lamp connected to the output end of the DC-DC converter by constant-current control, wherein

a capacitance of the output capacitor is set to a value, and a peak value of a pulse-like current flowing when the illumination lamp is instantaneously detached from and attached to the output end of the DC-DC converter is one or more and four or less times a load current of the illumination lamp.

2. The device of claim 1, wherein the capacitance of the output capacitor is 1 μ

F or less.

5. The device of claim 1, wherein the DC-DC converter is one of a chopper, a flyback converter, a forward converter and a switching regulator.

6. The device of claim 1, wherein the direct-current power supply converts an alternating-current power supplied from an alternating-current power supply into a direct-current power and supplies the direct-current power to the DC-DC converter.

7. A luminaire comprising:

an illumination lamp; and

a lighting device of claim 1.

8. The luminaire of claim 7, wherein the illumination lamp includes, as a light source, one of an LED, an EL, an organic light-emitting diode and an organic EL.

3. A lighting device comprising:

a lighting circuit that includes a direct-current power supply, a DC-DC converter having an input end connected to the direct-current power supply, and an output capacitor connected in parallel to an output end of the DC-DC converter, and lights an illumination lamp connected to the output end of the DC-DC converter by constant-current control, wherein

a capacitance of the output capacitor is set to a value, and a peak value of a pulse-like current flowing when the illumination lamp is instantaneously detached from and attached to the output end of the DC-DC converter is equal to or less than a maximum rated current value of the illumination lamp.

4. A lighting device comprising:

a lighting circuit that includes a direct-current power supply, a DC-DC converter having an input end connected to the direct-current power supply, and an output capacitor having a capacitance of 1 μ

F or less and connected in parallel to an output end of the DC-DC converter, and lights an illumination lamp connected to the output end of the DC-DC converter by constant-current control.