Multichip LED lighting device

• US 7,322,718 B2
• Filed: 12/22/2003
• Issued: 01/29/2008
• Est. Priority Date: 01/27/2003
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Tanimoto, Noriyasu, Matsui, Nobuyuki, Tamura, Tetsushi, Setomoto, Tatsumi, Shimizu, Masanori
• Primary Examiner(s): CROWE, DAVID R
• Application Number:
  US10/542,830
• Publication Number:
  US 20060087843A1
• Time in Patent Office: 1,499 Days
• Field of Search: 362/249, 362/652, 362/640, 362/646, 362/362, 362/373, 362/367, 362/218, 362/219, 362/221, 362/234, 362/276, 362/217, 362261-265, 362/295, 362/800, 315/291, 315/307, 315/309, 361728-731, 361/716
• US Class Current: 362/276
• CPC Class Codes: F21V 19/04 with provision for changing light source, e.g. turret auxiliary devices for cleaning, placing, or removing incandescent lamps H01K3/32, fluorescent lamps H01J9/006
• CPC Class Codes: F21V 23/006 the substrate being distinct from the light source holder
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/18 using temperature feedback
• CPC Class Codes: H05B 45/325 Pulse-width modulation [PWM]
• CPC Class Codes: H05B 45/395 Linear regulators
• CPC Class Codes: H05B 45/46 having LEDs disposed in parallel lines
• CPC Class Codes: H05B 45/56 involving measures to prevent abnormal temperature of the LEDs
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

In a module socket, a connecter and a connector are connected by wiring, and three LED modules are connected in parallel with respect to a constant voltage circuit unit via the wiring. Each module has a constant current circuit unit and an LED mounting unit. The constant current circuit unit includes one resistor and two transistors mounted on a surface of a sub-substrate on which a conductive land is formed. The sub-substrate is bonded to a main substrate.

Claims

1. A lighting device including a plurality of LED modules, each LED module in the plurality of LED modules comprising:

a main substrate;

an LED mounting unit composed of one or more LED bare chips mounted on a main surface of the main substrate;

a power supply terminal provided on the main surface of the main substrate, and operable to receive power from an electric power source;

a luminous intensity stabilization circuit connected electrically to the power supply terminal and the LED mounting unit; and

a thermal element unit connected to the luminous intensity stabilization circuit, and including a thermal element and a first comparator provided in a vicinity of an area in which the one or more LED bare chips are mounted,

wherein when at least one of the LED bare chips in any one of the LED modules rises in temperature to a predetermined temperature or higher, the luminous intensity stabilization circuit stops current to the one of the LED modules independently from any other of the LED modules in the plurality of LED modules, according to a judgment signal from the first comparator based on detected temperature information from the thermal element, and

each of the LED modules is individually detachable from the lighting device.

2. The lighting device of claim 1, wherein the luminous intensity stabilization circuit is a constant current circuit.

3. A lighting device comprising:

a plurality of LED modules, each LED module in the plurality of LED modules including;

a main substrate,

an LED mounting unit composed of one or more LED bare chips mounted on a main surface of the main substrate,

a power supply terminal provided on the main surface of the main substrate, and operable to receive power from an electric power source,

a luminous intensity stabilization circuit connected electrically to the power supply terminal and the LED mounting unit,

a thermal element unit connected to the luminous intensity stabilization circuit, and including a thermal element and a first comparator provided in a vicinity of an area in which the one or more LED bare chips are mounted;

one constant voltage circuit supplying a constant voltage to each LED module, using power from a power supply source; and

one logical circuit electrically connected to the constant voltage circuit and the thermal element unit of each LED module,

wherein, when at least one LED bare chip in at least one LED module rises in temperature to a predetermined temperature or higher, the constant voltage circuit supplies to all the LED modules, power to the power supply terminals such that the luminous intensity stabilization circuits stop current supplied to at least one of the LED mounting unit independently from any other LED modules in the plurality of LED modules, based on instruction information output from the logical circuit that is received, from the thermal element unit of the at least one LED module, a judgment signal of the first comparator based on detected temperature information of the thermal element of the at least one LED module.

4. A lighting device comprising:

a plurality of LED modules, each LED module in the plurality of LED modules including;

a main substrate,

an LED mounting unit composed of one or more LED bare chips mounted on a main surface of the main substrate,

a power supply terminal provided on the main surface of the main substrate, and operable to receive power from an electric power source,

a constant current circuit connected electrically to the power supply terminal and the LED mounting unit,

a thermal element unit connected to the constant current circuit, and including a thermal element and a first comparator provided in a vicinity of an area in which the one or more LED bare chips are mounted;

one constant voltage circuit supplying a constant voltage to each LED module, using power from a power supply source; and

one logical circuit electrically connected to the constant voltage circuit and the thermal element unit of each LED module,

wherein, when at least one LED bare chip in at least one LED module rises in temperature to a predetermined temperature or higher, the constant voltage circuit supplies to all the LED modules, power to the power supply terminals such that the constant current circuits stop current supplied to at least one of the LED mounting unit independently from any other LED modules in the plurality of LED modules, based on instruction information output from the logical circuit that is received, from the thermal element unit of the at least one LED module, a judgment signal of the first comparator based on detected temperature information of the thermal element of the at least one LED module, and

each of the LED modules is individually detachable from the lighting device.

5. A lighting device comprising:

a plurality of LED modules, each LED module in the plurality of LED modules including;

a main substrate,

an LED mounting unit composed of one or more LED bare chips mounted on a main surface of the main substrate,

a power supply terminal provided on the main surface of the main substrate, and operable to receive power from an electric power source,

a luminous intensity stabilization circuit connected electrically to the power supply terminal and the LED mounting unit,

a thermal element unit connected to the luminous intensity stabilization circuit, and including a thermal element and a first comparator provided in a vicinity of an area in which the one or more LED bare chips are mounted, and

a current detection unit including a second comparator connected to the one or more LED bare chips to detect a current amount,

wherein when at least one of the LED bare chips in any one of the LED modules rises in temperature to a predetermined temperature or higher, the luminous intensity stabilization circuit stops current to the one of the LED modules independently from any other of the LED modules in the plurality of LED modules, according to a judgment signal from the first comparator based on detected temperature information from the thermal element;

a constant voltage circuit supplying a constant voltage to each LED module, using power from a power supply source; and

a logical circuit electrically connected to the constant voltage circuit and the current detection unit,

wherein when the current amount in at least one LED bare chip in at least one LED module rises above a predetermined current amount, the constant voltage circuit supplies to all the LED modules, power to the power supply terminal such that the luminous intensity stabilization circuit reduces or stops current supplied to the LED mounting unit, based on instruction information output from the logical circuit that received, from the current detection unit of the at least one LED module, a judgment signal of the second comparator based on the detected current amount of the at least one LED module, and

each of the LED modules is individually detachable from the lighting device.

6. A lighting device comprising:

a plurality of LED modules, each LED module in the plurality of LED modules including;

a main substrate,

an LED mounting unit composed of one or more LED bare chips mounted on a main surface of the main substrate,

a power supply terminal provided on the main surface of the main substrate, and operable to receive power from an electric power source,

a constant current circuit connected electrically to the power supply terminal and the LED mounting unit,

a thermal element unit connected to the constant current circuit, and including a thermal element and a first comparator provided in a vicinity of an area in which the one or more LED bare chips are mounted, and

a current detection unit including a second comparator connected to the one or more LED bare chips to detect a current amount,

wherein when at least one of the LED bare chips in any one of the LED modules rises in temperature to a predetermined temperature or higher, the constant current circuit stops current to the one of the LED modules independently from any other of the LED modules in the plurality of LED modules, according to a judgment signal from the first comparator based on detected temperature information from the thermal element;

a constant voltage circuit supplying a constant voltage to each LED module, using power from a power supply source; and

a logical circuit electrically connected to the constant voltage circuit and the current detection unit,

wherein when the current amount in at least one LED bare chip in at least one LED module rises above a predetermined current amount, the constant voltage circuit supplies to all the LED modules, power to the power supply terminal such that the constant current circuit reduces or stops current supplied to the LED mounting unit, based on instruction information output from the logical circuit that received, from the current detection unit of the at least one LED module, a judgment signal of the second comparator based on the detected current amount of the at least one LED module, and

each of the LED modules is individually detachable from the lighting device.

7. A lighting device comprising:

a plurality of LED modules;

a constant voltage circuit supplying a constant voltage to each LED module, using power form a power supply source; and

a logical circuit electrically connected to the constant voltage circuit and a thermal element unit in each of the LED modules,

wherein each LED module includes;

a main substrate;

an LED mounting unit composed of one or more LED bare chips mounted on a main surface of the main substrate;

a power supply terminal provided on the main surface of the main substrate, and operable to receive voltage from the constant voltage circuit;

a constant current circuit connected electrically to the power supply terminal and the LED mounting unit; and

the thermal element unit connected to the constant current circuit, and including a thermal element and a comparator provided in a vicinity of an area in which the one or more LED bare chips are mounted;

wherein when at least one of the LED bare chips in any one of the LED modules rises in temperature to a predetermined temperature or higher, the constant voltage circuit stops voltage supply to the one of the LED modules independently from any other of the LED modules in the plurality of LED modules, according to a judgment signal from the comparator based on detected temperature information from the thermal element, and

each of the LED modules is individually detachable from the lighting device.

8. A lighting device comprising:

a plurality of LED modules, each LED module in the plurality of LED modules including;

a main substrate,

an LED mounting unit composed of one or more LED bare chips mounted on a main surface of the main substrate,

a power supply terminal provided on the main surface of the main substrate, and operable to receive power from an electric power source,

a constant current circuit connected electrically to the power supply terminal and the LED mounting unit,

a thermal element unit connected to the constant current circuit, and including a thermal element and a first comparator provided in a vicinity of an area in which the one or more LED bare chips are mounted, and

a current detection unit including a second comparator connected to the one or more LED bare chips to detect a current amount;

a constant voltage circuit supplying a constant voltage to each LED module, using power from a power supply source;

a first logical circuit electrically connected to the constant voltage circuit and the thermal element unit of each LED module,

wherein, when at least one LED bare chip in at least one LED module rises in temperature to a predetermined temperature or higher, the constant voltage circuit supplies to all the LED modules, power to the power supply terminal such that the constant current circuit stops current supplied to the LED mounting unit, based on instruction information output from the first logical circuit that is received, from the thermal element unit of the at least one LED module, a judgment signal of the first comparator based on detected temperature information of the thermal element of the at least one LED module; and

a second logical circuit electrically connected to the constant voltage circuit and the current detection unit,

wherein when the current amount in at least one LED bare chip in at least one LED module rises above a predetermined current amount, the constant voltage circuit supplies to all the LED modules, power to the power supply terminal such that the constant current circuit stops current supplied to the LED mounting unit, based on instruction information output from the second logical circuit that received, from the current detection unit of the at least one LED module, a judgment signal of the second comparator based on the detected current amount of the at least one LED module.

9. The lighting device of claim 8, wherein each of the LED modules is individually detachable from the lighting device.