Organic light emitting diode lighting systems

• US 8,288,951 B2
• Filed: 08/18/2009
• Issued: 10/16/2012
• Est. Priority Date: 08/19/2008
• Status: Expired due to Fees

• Current Assignee: Plextronics Incorporated (Rhodia Incorporated)
• Original Assignee: Plextronics Incorporated (Rhodia Incorporated)
• Inventors: Storch, Mark L., Mathai, Mathew K., Thompson, Glenn, Greenberg, Joseph
• Primary Examiner(s): Le, Don
• Application Number:
  US12/543,440
• Publication Number:
  US 20100045189A1
• Time in Patent Office: 1,155 Days
• Field of Search: 315149-154, 315/291, 315/294, 315/295, 315/297, 315307-309
• US Class Current: 315/152
• CPC Class Codes: H05B 47/10 Controlling the light source
• CPC Class Codes: H05B 47/165 following a pre-assigned programmed sequence; Logic control [LC]
• CPC Class Codes: H10K 50/00 Organic light-emitting devices integrated devices or assemblies of multiple devices H10K59/00, H10K65/00; organic semiconductor lasers H01S5/36
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels

Abstract

A lighting system includes a plurality of organic light emitting diode (OLED) devices. By selecting the plurality of OLED devices, or by selectively controlling the plurality of OLED devices, the color characteristics of the lighting system can be tuned. The lifetime of the lighting system can be improved.

Claims

1. A lighting system comprising:

a plurality of organic light emitting diode (OLED) devices;

a controller configured to selectively drive at least some of the plurality of OLED devices at different activation levels; and

a sensor configured to sense a degradation at least one of the plurality of OLED devices,

wherein at least one of the plurality of OLED devices comprises;

at least one coupler configured to electrically couple the OLED device to a power supply; and

an encapsulation that isolates the OLED device from an ambient environment,

wherein at least some of the plurality of OLED devices are redundant OLED devices, and

wherein the controller is configured to turn on one or more of the redundant OLED devices to compensate for the sensed degradation.

2. The lighting system of claim 1, wherein the controller is configured to selectively drive at least some of the plurality of OLED devices at different activation levels by controlling at least one of a drive voltage level, a drive current level, a pulse width, a pulse frequency, an on state, or an off state.

3. The lighting system of claim 1, wherein the controller is configured to selectively drive at least some of the plurality of OLED devices at different activation levels to improve a lifetime of the lighting system.

4. The lighting system of claim 1, wherein the controller is configured to selectively drive at least some of the plurality of OLED devices at different activation levels to improve a lifetime of the lighting system based on different wearing levels of the plurality of OLED devices.

5. The lighting system of claim 1, wherein the controller is configured to selectively drive at least some of the plurality of OLED devices at different activation levels to improve a lifetime of the lighting system based on different wearing levels of the plurality of OLED devices, and wherein a wearing level of an OLED device is determined based on one or more of an accumulative duration that the OLED device has been previously activated, a measured current, a capacitance, a junction temperature, or a luminance of the OLED device.

6. The lighting system of claim 1, wherein the controller is configured to selectively drive at least some of the plurality of OLED devices at different activation levels such that an output light has a desired color characteristic.

7. The lighting system of claim 6, wherein the controller is configured to selectively drive at least some of the plurality of OLED devices at different activation levels to compensate for degradation of some of the plurality of OLED devices thereby maintaining the desired color characteristic of the output light.

8. The lighting system of claim 6, wherein the desired color characteristic is one of a color temperature or a color rendering index.

9. The lighting system of claim 1, wherein the controller is configured to selectively drive at least some of the plurality of OLED devices at different activation levels such that an output light has a desired intensity and a desired color characteristic.

10. The lighting system of claim 1, wherein the controller is configured to selectively drive at least some of the plurality of OLED devices at different activation levels such that an output light has a desired intensity.

11. The lighting system of claim 1, further comprising a sensor configured to sense a degradation of at least one of the plurality of OLED devices, wherein the controller is configured to selectively drive at least some of the plurality of OLED devices at different activation levels to compensate for the sensed degradation.

12. The lighting system of claim 1, further comprising a sensor configured to sense a degradation of at least one of the plurality of OLED devices, wherein the sensor is configured to sense the degradation by measuring one of a temperature, a current, a capacitance, or a luminance of at least one of the plurality of OLED devices.

13. The lighting system of claim 1, wherein the controller is further configured to selectively drive at least some of the plurality of OLED devices at different activation levels to improve a lifetime of the lighting system and to have an output light with a desired color characteristic.

14. The lighting system of claim 1, wherein at least some of the plurality of OLED devices are vertically stacked.

15. The lighting system of claim 1, wherein at least some of the plurality of OLED devices are configured as edge-emitting OLED devices.

16. The lighting system of claim 1, wherein at least some of the plurality of OLED devices are vertically stacked, and wherein at least some of the plurality of OLED devices are substantially transparent.

17. The lighting system of claim 1, wherein the plurality of OLED devices include a first number of a first type of OLED devices and a second number of a second type of OLED devices, and wherein the first type of OLED devices have a light emission spectrum different from a light emission spectrum of the second type of OLED devices.

18. The lighting system of claim 1, wherein the plurality of OLED devices include a first number of a first type of OLED devices and a second number of a second type of OLED devices, and wherein the first type of OLED devices have a light emission spectrum different from a light emission spectrum of the second type of OLED devices, wherein the first type of OLED devices have an expected lifetime shorter than the second type of OLED devices, and wherein the first number is correspondingly larger than the second number.

19. The lighting system of claim 1, wherein the plurality of OLED devices include a first number of a first type of OLED devices and a second number of a second type of OLED devices, wherein the first type of OLED devices have a spectrum different from a spectrum of the second type of OLED devices, wherein the first type of OLED devices have a lifetime shorter than the second type of OLED devices, wherein the first number is correspondingly larger than the second number, and wherein the controller configured to selectively drive the first type of OLED devices at different activation levels such that not all of the first type of OLED devices are turned on at the same time thereby increasing the lifetime of the lighting system.

20. The lighting system of claim 1, further comprising a mount, wherein at least some of the plurality of OLED devices are configured to be removably coupled to the mount.

21. A lighting system comprising:

a plurality of organic light emitting diode (OLED) devices,

wherein each of the plurality of OLED devices has an active region,

wherein at least some of the OLED devices have active regions of different sizes,

wherein the different sizes are selected such that light emitted from the lighting system has desired color characteristics and that the OLED devices having active regions of different sizes have substantially matching lifetimes,

wherein the plurality of OLED devices include a first type of OLED devices each having an active region of a first size and a first expected lifetime, and a second type of OLED devices each having an active region of a second size and a second expected lifetime,

wherein a ratio of the first size to the second size is approximately proportional to a ratio of the second expected lifetime to the first expected lifetime,

wherein the first type of OLED devices are driven at a first current density, and the second type of OLED devices are driven at a second current density, and

wherein a ratio of the first current density to the second current density is approximately proportional to a ratio of the second size to the first size thereby substantially matching actual lifetimes of the first type of OLED devices and the second type of OLED devices.

22. The lighting system of claim 21, wherein the plurality of OLED devices include a first plurality of active regions configured to emit substantially red light, a second plurality of active regions configured to emit substantially green light, and a third plurality of active regions configured to emit substantially blue light, and wherein at least some of the third plurality of active regions have increased sizes and correspondingly reduced current densities as compared with the first plurality and the second plurality of active regions.

23. The lighting system of claim 21, wherein at least one of the plurality of OLED device comprises:

at least one coupler configured to electrically couple the OLED device to a power supply; and

an encapsulation that isolates the OLED device from an ambient environment.

24. A method comprising:

selectively controlling activation levels of at least some of a plurality of organic light emitting diode (OLED) devices in a lighting system to improve a lifetime of the lighting system

assigning addresses to the at least some of the plurality of OLED devices; and

swapping addresses between at least a first OLED device and a second OLED device among the at least some of the plurality of OLED devices,

wherein the first and second OLED devices have different wearing levels, and

wherein a wearing level of an OLED device is determined based on one or more of an accumulative duration that the OLED device has been previously activated, a measured current, a capacitance, a junction temperature, or a luminance of the OLED device.

25. The method of claim 24, further comprising determining wearing levels of the at least some of the plurality of OLED devices, wherein the selectively controlling activation levels of at least some of the plurality of OLED devices comprises selectively controlling the at least some of the plurality of OLED devices based on the determined wearing levels of the OLED devices.

26. The method of claim 24, wherein the plurality of OLED devices include a first number of blue OLED devices, a second number of red OLED devices, and a third number of green OLED devices, wherein the first number is about twice the second number, wherein the selectively controlling activation levels of at least some of the plurality of OLED devices comprises alternately activating blue OLED devices thereby increasing a lifetime of the lighting system.

27. A method, comprising:

selecting, from a plurality of pre-manufactured modular organic light emitting diode (OLED) devices, a subset of OLED devices; and

coupling the selected subset of OLED devices to a mount,

wherein the subset of OLED devices is selected to have a mixed output light spectrum with desired color characteristics,

wherein the selecting the subset of OLED devices comprises selecting a first number of a first type of OLED devices and a second number of a second type of OLED devices,

wherein the first type of OLED devices have a first spectrum different from a second spectrum of the second type of OLED devices,

wherein the first type of OLED devices have an expected lifetime substantially shorter than an expected lifetime the second type of OLED devices, and

wherein selecting the subset of OLED devices comprises selecting the first number substantially larger than the second number.

28. The method of claim 27, wherein the selecting the subset of OLED devices comprises selecting a first number of a first type of OLED devices and a second number of a second type of OLED devices, and wherein the first type of OLED devices have a first spectrum different from a second spectrum of the second type of OLED devices.

29. The method of claim 27, further comprising selectively activating the first type of OLED devices such that not all of the first type of OLED devices are activated at the same time or at the same activation level, thereby increasing the lifetime of the first type of OLED devices.

30. The method of claim 27, further comprising selectively activating the first type of OLED devices, wherein selectively activating the first type of OLED devices comprises electrically driving the first type of OLED devices with voltage or current pulses shorter than those of the second type of OLED devices.

31. The method of claim 27, further comprising selectively driving at least some of the subset of OLED devices with healing current pulses, wherein selectively driving at least some of the subset of OLED devices with healing current pulses comprises reversely biasing the devices during part of the current pulses to heal the devices.

32. The method of claim 27, further comprising selectively driving at least some of the plurality of OLED devices to different activation levels to compensate for degradation of some of the plurality of OLED devices thereby maintaining the desired output color characteristics.

33. The method of claim 27, further comprising:

sensing a degradation of one or more of the plurality of OLED devices; and

driving the one or more of the plurality of OLED devices at different activation levels to compensate for the sensed degradation.

34. The method of claim 27, further comprising:

sensing a degradation of one or more of the plurality of OLED devices, wherein at least some of the plurality of OLED devices are redundant OLED devices; and

turning on one or more of the redundant OLED devices to compensate for the sensed degradation.

35. The method of claim 27, further comprising sensing a degradation of one or more of the plurality of OLED devices by measuring one of a temperature, a current, a capacitance, or a luminance of the one or more of the plurality of OLED devices.

36. A lighting system comprising:

a plurality of organic light emitting diode (OLED) devices; and

a controller configured to selectively drive at least some of the plurality of OLED devices at different activation levels,

wherein at least one of the plurality of OLED devices comprises;

at least one coupler configured to electrically couple the OLED device to a power supply; and

an encapsulation that isolates the OLED device from an ambient environment,

wherein the plurality of OLED devices include a first number of a first type of OLED devices and a second number of a second type of OLED devices,

wherein the first type of OLED devices have a light emission spectrum different from a light emission spectrum of the second type of OLED devices,

wherein the first type of OLED devices have an expected lifetime shorter than the second type of OLED devices, and

wherein the first number is correspondingly larger than the second number.

37. A method comprising:

selectively controlling activation levels of at least some of a plurality of organic light emitting diode (OLED) devices in a lighting system to improve a lifetime of the lighting system,

wherein the plurality of OLED devices include a first number of blue OLED devices, a second number of red OLED devices, and a third number of green OLED devices,

wherein the first number is about twice the second number, and

wherein the selectively controlling activation levels of at least some of the plurality of OLED devices comprises alternately activating blue OLED devices thereby increasing a lifetime of the lighting system.

38. A method, comprising:

selecting, from a plurality of pre-manufactured modular organic light emitting diode (OLED) devices, a subset of OLED devices, wherein the subset of OLED devices is selected to have a mixed output light spectrum with desired color characteristics;

coupling the selected subset of OLED devices to a mount; and

selectively driving at least some of the subset of OLED devices with healing current pulses, wherein selectively driving at least some of the subset of OLED devices with healing current pulses comprises reversely biasing the devices during part of the current pulses to heal the devices.

39. A method, comprising:

selecting, from a plurality of pre-manufactured modular organic light emitting diode (OLED) devices, a subset of OLED devices, wherein the subset of OLED devices is selected to have a mixed output light spectrum with desired color characteristics;

coupling the selected subset of OLED devices to a mount;

sensing a degradation of one or more of the plurality of OLED devices, wherein at least some of the plurality of OLED devices are redundant OLED devices; and

turning on one or more of the redundant OLED devices to compensate for the sensed degradation.