LED WORK LIGHT

• US 20140036511A1
• Filed: 10/16/2013
• Published: 02/06/2014
• Est. Priority Date: 03/18/2004
• Status: Active Grant

• Current Assignee: Alltemp Products Company Limited (DiversiTech Holdings, Inc.)
• Original Assignee: Brasscorp Limited
• Inventors: WHITFIELD, Robert Tod, KLIPSTEIN, Donald L., BRASS, Jack, HILTS, Lorne
• Granted Patent: US 9,464,767 B2
• Time in Patent Office: Days
• US Class Current: 362/311.02
• 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 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 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.

2. The light emitting diode (LED) work light of claim 1 wherein aggregate illumination 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 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 transition time profile of a specified light source.

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

6. The light emitting diode (LED) work light of claim 1 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.

7. 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.

8. 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.

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

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

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

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

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

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

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

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

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

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

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

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

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

22. 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.

23. 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 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 state;

in response to activation of the control switch, transitioning the at least one LED from the first illumination state to a second illumination state of the illumination of the LEDs, the transitioning being illumination defined by a specified function over time defined to slow a transition time of the transitioning; and

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