LED work light

• US 9,464,767 B2
• Filed: 10/16/2013
• Issued: 10/11/2016
• Est. Priority Date: 03/18/2004
• Status: Active Grant

• Current Assignee: Alltemp Products Company Limited (DiversiTech Holdings, Inc.)
• Original Assignee: Cliplight Holdings, Ltd.
• Inventors: Whitfield, Robert Tod, Klipstein, Donald L., Brass, Jack, Hilts, Lorne
• Primary Examiner(s): PAYNE, SHARON E
• Application Number:
  US14/055,227
• Publication Number:
  US 20140036511A1
• Time in Patent Office: 1,091 Days
• Field of Search: 362/249.05
• US Class Current: 1/1
• CPC Class Codes: F21L 14/023 having two or more, or different light sources
• CPC Class Codes: F21L 4/00 Electric lighting devices with self-contained electric batteries or cells
• CPC Class Codes: F21L 4/08 characterised by means for in situ recharging of the batteries or cells
• CPC Class Codes: F21S 4/20 with light sources held by or within elongate supports
• CPC Class Codes: F21V 15/04 Resilient mountings, e.g. shock absorbers shock absorbing devices of vehicle headlamp housings B60Q1/0491; in general F16F15/04
• CPC Class Codes: F21V 17/12 by screwing
• CPC Class Codes: F21V 21/06 Bases for movable standing lamps; Fixing standards to the bases F21V21/08 takes precedence
• CPC Class Codes: F21V 21/08 Devices for easy attachment to any desired place, e.g. clip, clamp, magnet
• CPC Class Codes: F21V 21/32 Flexible tubes
• CPC Class Codes: F21V 21/406 for portable lighting devices
• CPC Class Codes: F21V 23/02 the elements being transformers, impedances or power supply units, e.g. a transformer with a rectifier
• CPC Class Codes: F21V 23/0435 activated by remote control means
• CPC Class Codes: F21V 27/005 for portable lighting devices
• CPC Class Codes: F21V 29/75 with fins or blades having different shapes, thicknesses or spacing
• CPC Class Codes: F21V 29/763 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21W 2131/402 for working places
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/325 : Pulse-width modulation [PWM]
• CPC Class Codes: Y02B 20/30 : Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A light emitting diode (LED) work light and associated method of controlling the LED work light. The LED work light includes a power source, a casing including a handle section, at least one LED mounted to illuminate light from the casing, at least one lens forward of the LEDs to focus light from the LEDs, a control switch designated to at least turn on and turn off the LEDs, and a controller. The controller may be configured to, in response to activation of the control switch, provide control of the power source to the LEDs to transition from a first illumination state to a second illumination state of the illumination of the LEDs, the transition being illumination defined by a specified function over time defined to slow a transition time of the transition.

Claims

1. A light emitting diode (LED) work light comprising:

a power source;

a casing including a handle section;

at least one LED mounted to illuminate light from the casing;

at least one lens forward of the LEDs to focus light from the LEDs;

a heatsink operably connected to the LEDs in a manner that achieves thermal contact with the LEDs;

a control switch designated to at least turn on and turn off the LEDs; and

a controller configured to, in response to activation of the control switch, provide control of the power source to the LEDs to transition from a first illumination intensity state to a second illumination intensity state of the illumination of the LEDs, the transition being illumination intensity defined by a specified function over time defined to slow a transition time of the transition versus the control switch alone, wherein the specified function is a monotonic function,

wherein for the transition the controller provides a pulse width control signal to the LEDs having a duty cycle proportional to an amount of illumination intensity.

2. The light emitting diode (LED) work light of claim 1 wherein aggregate illumination intensity of the LEDs is controlled by the controller in accordance with the specified function.

3. The light emitting diode (LED) work light of claim 1 wherein individual illumination intensity of each of the LEDs is controlled by the controller in accordance with the specified function.

4. The light emitting diode (LED) work light of claim 1 wherein the transition of the LEDs is controlled by the controller to match an associated illumination intensity transition time profile of a specified reference light source which is not any one of the LEDs.

5. The light emitting diode (LED) work light of claim 4 wherein the specified reference light source is a fluorescent gas light source.

6. The light emitting diode (LED) work light of claim 1 wherein the duty cycle of the pulse width control signal is increasing or decreasing during the transition time.

7. The light emitting diode (LED) work light of claim 1 further comprising a sensor for providing a feedback signal to the controller to facilitate feedback control of the transition.

8. The light emitting diode (LED) work light of claim 7 wherein the sensor comprises a resistor.

9. The light emitting diode (LED) work light of claim 1 wherein the specified function is an exponential function.

10. The light emitting diode (LED) work light of claim 1 wherein the specified function is a monotonic portion of a sinusoidal function.

11. The light emitting diode (LED) work light of claim 1 wherein the specified function is a monotonic portion of a polynomial function.

12. The light emitting diode (LED) work light of claim 1 wherein the specified function is a monotonic portion of a power function.

13. The light emitting diode (LED) work light of claim 1 wherein the controller is configured to implement the transition as an increase in illumination intensity.

14. The light emitting diode (LED) work light of claim 13 wherein the controller is further configured to implement the transition as a decrease in illumination intensity.

15. The light emitting diode (LED) work light of claim 1 wherein at least one of the first illumination intensity state and the second illumination intensity state are an illumination intensity state between a zero illumination intensity state and a maximum illumination intensity state of the LED.

16. The light emitting diode (LED) work light of claim 1 wherein one of the first intensity illumination state and the second intensity illumination state is a zero illumination intensity state and the other of the first illumination intensity state and the second illumination intensity state is a maximum illumination intensity state of the LED.

17. The light emitting diode (LED) work light of claim 1 wherein the transition time ranges from about 0.1 to 4 seconds.

18. The light emitting diode (LED) work light of claim 1 wherein the transition time ranges from about 0.25 to 3 seconds.

19. The light emitting diode (LED) work light of claim 1 wherein the transition time ranges from about 1 to 1.5 seconds.

20. The light emitting diode (LED) work light of claim 1 wherein the LEDs are of different types having different native rise time responses to an applied power source, the LEDs being controlled to have a same rise time as each other according to the specified function.

21. A method of controlling a light emitting diode (LED) work light including a power source, a casing including a handle section, at least one LED mounted to illuminate light from the casing, at least one lens forward of the LEDs to focus light from the LEDs, a heatsink operably connected to the LEDs in a manner that achieves thermal contact with the LEDs, a control switch designated to at least turn on and turn off the LEDs, the method being implemented by a controller and comprising:

controlling the at least one LED to have a first illumination intensity state;

in response to activation of the control switch, transitioning the at least one LED from the first illumination intensity state to a second illumination intensity state of the illumination of the LEDs, the transitioning being illumination intensity defined by a specified function over time defined to slow a transition time of the transitioning versus the control switch alone, wherein the specified function is a monotonic function, wherein for the transition the controller provides a pulse width control signal to the LEDs having a duty cycle proportional to an amount of illumination intensity; and

after the transitioning, controlling the at least one LED to have the second illumination intensity state.