Lighting apparatus and lighting fitting

• US 9,103,521 B2
• Filed: 12/27/2011
• Issued: 08/11/2015
• Est. Priority Date: 12/27/2010
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Nishitani, Daisuke, Nishii, Takahito, Kamizono, Tsutomu, Nakano, Takahiro
• Primary Examiner(s): VO, TUYET THI
• Application Number:
  US13/337,554
• Publication Number:
  US 20120161633A1
• Time in Patent Office: 1,323 Days
• Field of Search: 315/309, 315/307, 315/291, 315/224, 315/185.S
• US Class Current: 1/1
• CPC Class Codes: B60Q 1/0023 the element being a sensor, e.g. distance sensor, camera
• CPC Class Codes: B60Q 1/085 due to special conditions, e.g. adverse weather, type of road, badly illuminated road signs or potential dangers B60Q1/10, B60Q1/12, B60Q1/1423 take precedence
• CPC Class Codes: B60Q 1/143 combined with another condition, e.g. using vehicle recognition from camera images or activation of wipers
• CPC Class Codes: B60Q 11/005 for lighting devices, e.g. indicating if lamps are burning or not
• CPC Class Codes: B60Q 2300/14 Other vehicle conditions
• CPC Class Codes: F21S 41/148 the main emission direction of the LED being perpendicular to the optical axis
• CPC Class Codes: F21S 41/151 arranged in one or more lines
• CPC Class Codes: F21S 41/19 Attachment of light sources or lamp holders achieving variable light distribution by movable light sources F21S41/657
• CPC Class Codes: F21S 45/43 using gas
• CPC Class Codes: F21S 45/47 Passive cooling, e.g. using fins, thermal conductive elements or openings
• CPC Class Codes: F21V 23/007 enclosed in a casing
• CPC Class Codes: F21V 29/60 characterised by the use of a forced flow of gas, e.g. air
• CPC Class Codes: F21V 29/71 using a combination of separate elements interconnected by heat-conducting means, e.g. with heat pipes or thermally conductive bars between separate heat-sink elements
• CPC Class Codes: F21V 29/763 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/18 using temperature feedback

Abstract

A lighting apparatus is provided which includes a drive section which applies electric current to a light source which is a semiconductor element emitting light with application of electric current, at least one heat sink which is mounted with the light source and transfers heat generated by the emission of the light source, and a temperature measurement section which is mounted to the heat sink and measures temperature of the heat sink which is used for estimating temperature of the light source. The light source and the drive section are mounted to the same heat sink or to the heat sinks which are thermally coupled to each other.

Claims

1. A lighting apparatus, comprising:

a drive section which applies electric current to a light source which is a semiconductor element emitting light with application of electric current;

at least one heat sink which is mounted with the light source and transfers heat generated by the emission of the light source; and

a temperature measurement section which is mounted to the heat sink and measures temperature of the heat sink which is used for estimating temperature of the light source, wherein

the light source and the drive section are mounted to the same heat sink or to the heat sinks which are thermally coupled to each other; and

at relative positions of the temperature measurement section, the light source, and a heat generating portion in the drive section, influence of heat received by the temperature measurement section from the light sources is larger than influence of heat received by the temperature measurement section from the heat generating portion in the drive section.

2. The lighting apparatus according to claim 1, further comprising

a controller which controls the drive section, wherein

the controller stores a correlation between current and light output and a correlation between temperature and light output, which depend on the type of the semiconductor element, in advance, and

the controller determines the type of the semiconductor element which is used as the light source to which current is applied by the drive section, and controls the current applied to the light source from the drive section depending on the determined type of the semiconductor element.

3. The lighting apparatus according to claim 1, further comprising:

a fan which blows air to at least one of the heat sink and the light source; and

a controller which controls rotation of the fan based on the temperature measured by the temperature measurement section, wherein

the controller stores a correlation between current and light output and a correlation between temperature and light output of the light source, and

the controller controls the number of revolutions of the fan so that at least one of the light output of the light source and the temperature of the light source falls within a predetermined range.

4. A lighting fitting, comprising:

a light source which is a semiconductor element emitting light with application of electric current;

the lighting apparatus according to claim 1; and

a casing which accommodates the light source and the lighting apparatus.

5. A lighting apparatus, comprising:

a drive section which applies electric current to a light source which is a semiconductor element emitting light with application of electric current;

at least one heat sink which is mounted with the light source and transfers heat generated by the emission of the light source; and

a temperature measurement section which is mounted to the heat sink and measures temperature of the heat sink which is used for estimating temperature of the light source, wherein

the light source and the drive section are mounted to the same heat sink or to the heat sinks which are thermally coupled to each other;

the controller calculates a rate of temperature variation which is the variation with passage of time of the temperature measured by the temperature measurement section, and determines presence/absence of a failure of the light source based on the rate of temperature variation.

6. The lighting apparatus according to claim 5, further comprising

a controller which controls the drive section, wherein

the controller stores a correlation between current and light output and a correlation between temperature and light output, which depend on the type of the semiconductor element, in advance, and

the controller determines the type of the semiconductor element which is used as the light source to which current is applied by the drive section, and controls the current applied to the light source from the drive section depending on the determined type of the semiconductor element.

7. The lighting apparatus according to claim 5, further comprising:

a fan which blows air to at least one of the heat sink and the light source; and

a controller which controls rotation of the fan based on the temperature measured by the temperature measurement section, wherein

the controller stores a correlation between current and light output and a correlation between temperature and light output of the light source, and

the controller controls the number of revolutions of the fan so that at least one of the light output of the light source and the temperature of the light source falls within a predetermined range.

8. A lighting fitting, comprising:

a light source which is a semiconductor element emitting light with application of electric current;

the lighting apparatus according to claim 5; and

a casing which accommodates the light source and the lighting apparatus.