Lighting Apparatus And Lighting Fixture

• US 20110095691A1
• Filed: 08/18/2010
• Published: 04/28/2011
• Est. Priority Date: 08/19/2009
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Inventors: Kakehashi, Hidenori, Kido, Hiroshi, Goto, Katsuyoshi, Hiramatsu, Kohji, Ura, Ryusuke, Nakajo, Akira
• Granted Patent: US 8,310,162 B2
• Time in Patent Office: Days
• US Class Current: 315/133
• CPC Class Codes: H05B 47/20 Responsive to malfunctions or to light source life; for protection
• CPC Class Codes: H05B 47/28 Circuit arrangements for protecting against abnormal temperature

Abstract

A lighting apparatus includes a lighting circuit unit, a timer unit, a life judgment unit, a timing adjustment unit, and an indication unit. The lighting circuit unit is configured to activate a light source. The timer unit is configured to measure accumulated operation time of the lighting circuit unit. The life judgment unit is configured to store a first judgment time and a second judgment time longer than the first judgment time. The life judgment unit is configured to compare the accumulated operation time with the first judgment time and output a first judgment signal when the accumulated operation time becomes equal to the first judgment time. The life judgment unit is configured to compare the accumulated operation time with the second judgment time and output a second judgment signal when the accumulated operation time becomes equal to the second judgment time. The timing adjustment unit is configured to vary timing at which the life judgment unit outputs the first judgment signal. The timing adjustment unit is configured to vary timing at which the life judgment unit outputs the second judgment signal. The indication unit is configured to indicate, upon receiving the first judgment signal from the life judgment unit, a first level of the end of life with the light source kept turned on. The indication unit is configured to indicate, upon receiving the second judgment signal from the life judgment unit, a second level of the end of life. The second level of the end of life is later than the first level of the end of life.

Claims

1. A lighting apparatus comprising:

a lighting circuit unit configured to activate a light source;

a timer unit configured to measure accumulated operation time of said lighting circuit unit;

a life judgment unit configured to store a first judgment time and a second judgment time longer than said first judgment time, said life judgment unit being configured to compare said accumulated operation time with said first judgment time and output a first judgment signal when said accumulated operation time becomes equal to said first judgment time, and said life judgment unit being configured to compare said accumulated operation time with said second judgment time and output a second judgment signal when said accumulated operation time becomes equal to said second judgment time;

a timing adjustment unit configured to vary timing at which said life judgment unit outputs said first judgment signal and timing at which said life judgment unit outputs said second judgment signal;

an indication unit configured to indicate, upon receiving said first judgment signal from said life judgment unit, a first level of the end of life with said light source kept turned on, said indication unit being configured to indicate, upon receiving said second judgment signal from said life judgment unit, a second level of the end of life, and said second level of the end of life is later than the first level of the end of life.

2. A lighting apparatus as set forth in claim 1, wherein

said timing adjustment unit is configured to vary said first judgment time and said second judgment time respectively,

said life judgment unit being configured to compare said accumulated operation time measured by said timer unit with said first judgment time varied by said timing adjustment unit and output said first judgment signal when said accumulated operation time measured by said timer unit becomes equal to said first judgment time varied by said timing adjustment unit, and said life judgment unit being configured to compare said accumulated operation time measured by said timer unit with said second judgment time varied by said timing adjustment unit and output said second judgment signal when said accumulated operation time measured by said timer unit becomes equal to said second judgment time varied by said timing adjustment unit.

3. A lighting apparatus as set forth in claim 2, wherein

said timing adjustment unit is configured to randomly vary said first judgment time within a first variation width and to randomly vary said second judgment time within a second variation width.

4. A lighting apparatus as set forth in claim 3, wherein

said lighting circuit unit is configured to activate said light source selected from an electrodeless discharge lamp, a light emitting diode, and an organic electroluminescence device.

5. A lighting fixture comprising:

a light source;

a lighting apparatus defined by claim 3.

6. A lighting apparatus as set forth in claim 2, wherein

said lighting apparatus includes a detection unit configured to detect at least one of a temperature of said lighting apparatus, a voltage applied to said lighting apparatus, and a current flowing through said lighting apparatus, and output detection value indicative thereof,

said timing adjustment unit being configured to respectively vary said first judgment time and said second judgment time according to said detection value received from said detection unit,

said second level of the end of life being defined as the last level of the end of life, and

said second judgment time being shorter than an end of life of any component of said lighting circuit unit.

7. A lighting apparatus as set forth in claim 6, wherein

said lighting circuit unit is configured to activate said light source selected from an electrodeless discharge lamp, a light emitting diode, and an organic electroluminescence device.

8. A lighting fixture comprising:

a light source;

a lighting apparatus defined by claim 6.

9. A lighting apparatus as set forth in claim 3, wherein

said first level of the end of life is defined as the initial level of the end of life,

said second level of the end of life being defined as the last level of the end of life, and

said first variation width and said second variation width being selected such that the maximum of the first judgment time within said first variation width is shorter than the minimum of said second judgment time within said second variation width.

10. A lighting apparatus as set forth in claim 3, wherein

said second variation width is greater than said first variation width.

11. A lighting apparatus as set forth in claim 1, wherein

said timing adjustment unit is configured to vary said accumulated operation time measured by said timer,

said life judgment unit being configured to compare said accumulated operation time varied by said timing adjustment unit with said first judgment time and output said first judgment signal when said accumulated operation time varied by said timing adjustment unit becomes equal to said first judgment time, and said life judgment unit being configured to compare said accumulated operation time varied by said timing adjustment unit with said second judgment time and output said second judgment signal when said accumulated operation time varied by said timing adjustment unit becomes equal to said second judgment time.

12. A lighting apparatus as set forth in claim 11, wherein

said timer unit comprises an oscillator configured to output a clock signal at a constant period, and a counting circuit configured to count the number of said clock signals output from said oscillator,

said timing adjustment unit being configured to randomly vary a threshold for said counting circuit within a predetermined variation width, and

said counting circuit being configured to increase said accumulated operation time by a constant amount each time when the number of said clock signals output from said oscillator becomes identical to said threshold varied by said timing adjustment unit, thereby measuring said accumulated operation time.

13. A lighting apparatus as set forth in claim 11, wherein

said lighting apparatus includes a detection unit configured to detect at least one of a temperature of said lighting apparatus, a voltage applied to said lighting apparatus, and a current flowing through said lighting apparatus, and output detection value indicative thereof,

said timing adjustment unit being configured to vary said accumulated operation time according to said detection value received from said detection unit,

said second level of the end of life being defined as the last level of the end of life, and

said second judgment time being shorter than an end of life of any component of said lighting circuit unit.