Lighting assembly and lighting method

• US 9,310,026 B2
• Filed: 12/03/2007
• Issued: 04/12/2016
• Est. Priority Date: 12/04/2006
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Negley, Gerald H.
• Primary Examiner(s): Husar, Stephen F
• Application Number:
  US11/949,222
• Publication Number:
  US 20080130282A1
• Time in Patent Office: 3,053 Days
• Field of Search: 362/249.01, 362/249.02, 362/249.06, 362/249.16, 362/249.14, 362/246
• US Class Current: 1/1
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: F21V 5/10 comprising photoluminescent material
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

There is provided a lighting assembly comprising a plurality of lighting devices, each of which comprises a patterned diffuser having optical features. Each of the lighting devices is positioned such that if they are illuminated, at least 50, and in some cases 75 or more, percent of light emitted from each of the lighting devices will contact an illumination surface within an area of a defined shape (e.g., square, rectangular, hexagonal, octagonal, etc.), the respective shapes each sharing at least one boundary with another shape. Also, methods of lighting comprising illuminating lighting devices positioned in such a way.

Claims

1. A lighting assembly comprising:

at least first, second, third, fourth and fifth lighting devices; and

at least first, second, third, fourth and fifth patterned diffusers, each of said patterned diffusers comprising a plurality of optical features and configured to cause at least 75% of light that enters the patterned diffuser to exit the patterned diffuser to produce a rectangular pattern of light, regardless of the pattern of the light which enters the patterned diffuser,

the first patterned diffuser positioned to receive light from the first lighting device,

the second patterned diffuser positioned to receive light from the second lighting device,

the third patterned diffuser positioned to receive light from the third lighting device,

the fourth patterned diffuser positioned to receive light from the fourth lighting device,

the fifth patterned diffuser positioned to receive light from the fifth lighting device,

wherein said first, second, third, fourth and fifth lighting devices and said first, second, third, fourth and fifth patterned diffusers arc configured and positioned such that when each of said first, second, third, fourth and fifth lighting devices is illuminated so that each of said first, second, third, fourth and fifth lighting devices emits light, a planar illumination surface can be positioned such that at least a portion of light emitted from each of said first, second, third, fourth and fifth lighting devices travels in a direction substantially perpendicular to said illumination surface, and;

at least 75 percent of light that passes through the first patterned diffuser projects into a first rectangular area on said surface defined by a first line segment, a second line segment, a third line segment and a fourth line segment;

at least 75 percent of light that passes through the second patterned diffuser projects into a second rectangular area on said surface defined by said first line segment, a fifth line segment, a sixth line segment and a seventh line segment;

at least 75 percent of light that passes through the third patterned diffuser projects into a third rectangular area on said surface defined by said second line segment, an eighth line segment, a ninth line segment and a tenth line segment;

at least 75 percent of light that passes through the fourth patterned diffuser projects into a fourth rectangular area on said surface defined by said third line segment, an eleventh line segment, a twelfth line segment and a thirteenth line segment;

at least 75 percent of light that passes through the fifth patterned diffuser projects into a fifth rectangular area on said surface defined by said fourth line segment, a fourteenth line segment, a fifteenth line segment and a sixteenth line segment.

2. A lighting assembly as recited in claim 1, wherein said first lighting device comprises at least one solid state light emitter.

3. A lighting assembly as recited in claim 1, wherein at least some light emitted by a light source in said first lighting device enters said first patterned diffuser through a first surface of said first patterned diffuser and exits said first patterned diffuser through a second surface of said first patterned diffuser.

4. A lighting assembly as recited in claim 3, wherein a plurality of optical features are on said first surface of said first patterned diffuser.

5. A lighting assembly comprising:

at least first, second, third, fourth and fifth lighting devices; and

at least first, second, third, fourth and fifth patterned diffusers, each of said patterned diffusers comprising a plurality of optical features and configured to cause at least 75% of light that enters the patterned diffuser to exit the patterned diffuser to produce a square pattern of light, regardless of the pattern of the light which enters the patterned diffuser,

the first patterned diffuser positioned to receive light from the first lighting device,

the second patterned diffuser positioned to receive light from the second lighting device,

the third patterned diffuser positioned to receive light from the third lighting device,

the fourth patterned diffuser positioned to receive light from the fourth lighting device,

the fifth patterned diffuser positioned to receive light from the fifth lighting device.

wherein said first, second, third, fourth and fifth lighting devices and said first, second, third, fourth and fifth patterned diffusers are configured and positioned such that when each of said first, second, third, fourth and fifth lighting devices is illuminated so that each of said first, second, third, fourth and fifth lighting devices emits light, a planar illumination surface can be positioned such that at least a portion of light emitted from each of said first, second, third, fourth and fifth lighting devices travels in a direction substantially perpendicular to said illumination surface, and;

at least 75 percent of light that passes through the first patterned diffuser projects into a first square area on said surface defined by a first line segment, a second line segment, a third line segment and a fourth line segment;

at least 75 percent of light that passes through the second patterned diffuser projects into a second square area on said surface defined by said first line segment, a fifth line segment, a sixth line segment and a seventh line segment;

at least 75 percent of light that passes through the third patterned diffuser projects into a third square area on said surface defined by said second line segment, an eighth line segment, a ninth line segment and a tenth line segment;

at least 75 percent of light that passes through the fourth patterned diffuser projects into a fourth square area on said surface defined by said third line segment, an eleventh line segment, a twelfth line segment and a thirteenth line segment;

at least 75 percent of light that passes through the fifth patterned diffuser projects into a fifth square area on said surface defined by said fourth line segment, a fourteenth line segment, a fifteenth line segment and a sixteenth line segment.

6. A lighting assembly as recited in claim 5, wherein said first lighting device comprises at least one solid state light emitter.

7. A lighting assembly as recited in claim 5, wherein at least some light emitted by a light source in said first lighting device enters said first patterned diffuser through a first surface of said first patterned diffuser and exits said first patterned diffuser through a second surface of said first patterned diffuser.

8. A lighting assembly as recited in claim 7, wherein a plurality of optical features are on said first surface of said first patterned diffuser.

9. A lighting assembly comprising:

at least first, second, third, fourth, fifth, sixth and seventh lighting devices; and

at least first, second, third, fourth, fifth, sixth and seventh patterned diffusers, each of said patterned diffusers comprising a plurality of optical features and configured to cause at least 75% of light that enters the patterned diffuser to exit the patterned diffuser to produce a hexagonal pattern of light, regardless of the pattern of the light which enters the patterned diffuser,

the first patterned diffuser positioned to receive light from the first lighting device,

the second patterned diffuser positioned to receive light from the second lighting device,

the third patterned diffuser positioned to receive light from the third lighting device,

the fourth patterned diffuser positioned to receive light from the fourth lighting device,

the fifth patterned diffuser positioned to receive light from the fifth lighting device,

the sixth patterned diffuser positioned to receive light from the sixth lighting device,

the seventh patterned diffuser positioned to receive light from the seventh lighting device,

wherein said first, second, third, fourth, fifth, sixth and seventh lighting devices and said first, second, third, fourth, fifth, sixth and seventh patterned diffusers are configured such that when each of said first, second, third, fourth, fifth, sixth and seventh lighting devices is illuminated so that each of said first, second, third, fourth, fifth, sixth and seventh lighting devices emits light, a planar illumination surface can be positioned such that at least a portion of light emitted from each of said first, second, third, fourth, fifth, sixth and seventh lighting devices travels in a direction substantially perpendicular to said illumination surface, and;

at least 75 percent of light that passes through the first patterned diffuser projects into a first hexagonal area on said surface defined by a first line segment, a second line segment, a third line segment, a fourth line segment, a fifth line segment and a sixth line segment;

at least 75 percent of light that passes through the second patterned diffuser projects into a second hexagonal area on said surface defined by the first line segment, a seventh line segment, an eighth line segment, a ninth line segment, a tenth line segment and an eleventh line segment;

at least 75 percent of light that passes through the third patterned diffuser projects into a third hexagonal area on said surface defined by the second line segment, the eleventh line segment, a twelfth line segment, a thirteenth line segment, a fourteenth line segment and a fifteenth line segment;

at least 75 percent of light that passes through the fourth patterned diffuser projects into a fourth hexagonal area on said surface defined by the third line segment, the fifteenth line segment, a sixteenth line segment, a seventeenth line segment, an eighteenth line segment and a nineteenth line segment;

at least 75 percent of light that passes through the fifth patterned diffuser projects into a fifth hexagonal area on said surface defined by the fourth line segment, the nineteenth line segment, a twentieth line segment, a twenty-first line segment, a twenty-second line segment and a twenty-third line segment;

at least 75 percent of light that passes through the sixth patterned diffuser projects into a sixth hexagonal area on said surface defined by the fifth line segment, the twenty-third line segment, a twenty-fourth line segment, a twenty-fifth line segment, a twenty-sixth line segment and a twenty-seventh line segment;

at least 75 percent of light that passes through the seventh patterned diffuser projects into a seventh hexagonal area on said surface defined by the sixth line segment, the seventh line segment, the twenty-seventh line segment, a twenty-eighth line segment, a twenty-ninth line segment and a thirtieth line segment.

10. A lighting assembly as recited in claim 9, wherein said first lighting device comprises at least one solid state light emitter.

11. A lighting assembly as recited in claim 9, wherein at least some light emitted by a light source in said first lighting device enters said first patterned diffuser through a first surface of said first patterned diffuser and exits said first patterned diffuser through a second surface of said first patterned diffuser.

12. A lighting assembly as recited in claim 11, wherein a plurality of optical features are on said first surface of said first patterned diffuser.

13. A lighting assembly comprising:

at least first, second, third, fourth, fifth, sixth, seventh, eighth and ninth lighting devices

at least first, second, third, fourth, fifth, sixth, seventh, eighth and ninth patterned diffusers, each of said patterned diffusers comprising a plurality of optical features and configured to cause at least 75% of light that enters the patterned diffuser to exit the patterned diffuser to produce an octagonal pattern of light or a square pattern of light, regardless of the pattern of the light which enters the patterned diffuser,

the first patterned diffuser positioned to receive light from the first lighting device,

the second patterned diffuser positioned to receive light from the second lighting device,

the third patterned diffuser positioned to receive light from the third lighting device,

the fourth patterned diffuser positioned to receive light from the fourth lighting device,

the fifth patterned diffuser positioned to receive light from the fifth lighting device,

the sixth patterned diffuser positioned to receive light from the sixth lighting device,

the seventh patterned diffuser positioned to receive light from the seventh lighting device,

the eighth patterned diffuser positioned to receive light from the eighth lighting device,

the ninth patterned diffuser positioned to receive light from the ninth lighting device,

wherein said first second, third, fourth, fifth, sixth, seventh, eighth and ninth lighting devices and said first, second, third, fourth, fifth, sixth, seventh, eighth and ninth patterned diffusers are configured and positioned such that when each of said first, second, third, fourth, fifth, sixth, seventh, eighth and ninth lighting devices is illuminated so that each of said first, second, third, fourth, fifth, sixth, seventh, eighth and ninth lighting devices emits light, planar illumination surface can be positioned such that at least a portion of light emitted from each of said first, second, third, fourth and fifth lighting devices travels in a direction substantially perpendicular to said illumination surface, and;

at least 75 percent of light that passes through the first patterned diffuser projects into a first octagonal area on said surface defined by a first line segment, a second line segment, a third line segment, a fourth line segment, a fifth line segment, a sixth line segment, a seventh line segment and an eighth line segment;

at least 75 percent of light that passes through the second patterned diffuser projects into a first square area on said surface defined by the first line segment, a ninth line segment, a tenth line segment and an eleventh line segment;

at least 75 percent of light that passes through the third patterned diffuser projects into a second octagonal area on said surface defined by the second line segment, the eleventh line segment, a twelfth line segment, a thirteenth line segment, a fourteenth line segment, a fifteenth line segment, a sixteenth line segment and a seventeenth line segment;

at least 75 percent of light that passes through the fourth patterned diffuser projects into a second square area on said surface defined by the third line segment, the seventeenth line segment, an eighteenth line segment and a nineteenth line segment;

at least 75 percent of light that passes through the fifth patterned diffuser projects into a third octagonal area on said surface defined by the fourth line segment, the nineteenth line segment, a twentieth line segment, a twenty-first line segment, a twenty-second line segment, a twenty-third line segment, a twenty-fourth line segment and a twenty-fifth line segment;

at least 75 percent of light that passes through the sixth patterned diffuser projects into a third square area on said surface defined by the fifth line segment, the twenty-fifth line segment, a twenty-sixth line segment and a twenty-seventh line segment;

at least 75 percent of light that passes through the seventh patterned diffuser projects into a fourth octagonal area on said surface defined by the sixth line segment, the twenty-seventh line segment, a twenty-eighth line segment, a twenty-ninth line segment, a thirtieth line segment, a thirty-first line segment, a thirty-second line segment and a thirty-third line segment;

at least 75 percent of light that passes through the eighth patterned diffuser projects into a fourth square area on said surface defined by the seventh line segment, the thirty-third line segment, a thirty-fourth line segment and a thirty-fifth line segment;

at least 75 percent of light that passes through the ninth patterned diffuser projects into a fifth octagonal area on said surface defined by the eighth line segment, the ninth line segment, the thirty-fifth line segment, a thirty-sixth line segment, a thirty-seventh line segment, a thirty-eighth line segment, a thirty-ninth line segment and a fortieth line segment.

14. A lighting assembly as recited in claim 13, wherein said first lighting device comprises at least one solid state light emitter.

15. A lighting assembly as recited in claim 13, wherein at least some light emitted by a light source in said first lighting device enters said first patterned diffuser through a first surface of said first patterned diffuser and exits said first patterned diffuser through a second surface of said first patterned diffuser.

16. A lighting assembly as recited in claim 15, wherein a plurality of optical features are on said first surface of said first patterned diffuser.

17. A method of lighting comprising:

illuminating first, second, third, fourth and fifth lighting devices so that each of said first, second, third, fourth and fifth lighting devices emits light in a lighting assembly,

light from said first lighting device entering a first patterned diffuser,

light from said second lighting device entering a second patterned diffuser,

light from said third lighting device entering a third patterned diffuser,

light from said fourth lighting device entering a fourth patterned diffuser,

light from said fifth lighting device entering a fifth patterned diffuser,

each of said patterned diffusers comprising a plurality of optical features configured to cause at least 75% of light that enters the patterned diffuser to exit the patterned diffuser to produce a rectangular pattern of light, regardless of the pattern of the light which enters the patterned diffuser, so that a planar illumination surface can be positioned such that at least a portion of light emitted from each of said first, second, third, fourth and fifth lighting devices travels in a direction substantially perpendicular to said illumination surface, and;

at least 75 percent of light that passes through the first patterned diffuser projects onto said illumination surface an illuminated first rectangular area on said surface defined by a first line segment, a second line segment, a third line segment and a fourth line segment;

at least 75 percent of light that passes through the second patterned diffuser projects onto said illumination surface an illuminated second rectangular area on said surface defined by said first line segment, a fifth line segment, a sixth line segment and a seventh line segment;

at least 75 percent of light that passes through the third patterned diffuser projects onto said illumination surface an illuminated third rectangular area on said surface defined by said second line segment, an eighth line segment, a ninth line segment and a tenth line segment;

at least 75 percent of light that passes through the fourth patterned diffuser projects onto said illumination surface an illuminated fourth rectangular area on said surface defined by said third line segment, an eleventh line segment, a twelfth line segment and a thirteenth line segment;

at least 75 percent of light that passes through the fifth patterned diffuser projects onto said illumination surface an illuminated fifth rectangular area on said surface defined by said fourth line segment, a fourteenth line segment, a fifteenth line segment and a sixteenth line segment.

18. A method as recited in claim 17, wherein said first lighting device comprises at least one solid state light emitter.

19. A method as recited in claim 17, wherein at least some light emitted by a light source in said first lighting device enters said first patterned diffuser through a first surface of said first patterned diffuser and exits said first patterned diffuser through a second surface of said first patterned diffuser.

20. A method as recited in claim 19, wherein a plurality of optical features are on said first surface of said first patterned diffuser.

21. A method of lighting comprising:

illuminating first, second, third, fourth and fifth lighting devices so that each of said first, second, third, fourth and fifth lighting devices emits light in a lighting assembly,

light from said first lighting device entering a first patterned diffuser,

light from said second lighting device entering a second patterned diffuser,

light from said third lighting device entering a third patterned diffuser,

light from said fourth lighting device entering a fourth patterned diffuser,

light from said fifth lighting device entering a fifth patterned diffuser,

each of said patterned diffusers comprising a plurality of optical features configured to cause at least 75% of light that enters the patterned diffuser to exit the patterned diffuser to produce a square pattern of light, regardless of the pattern of the light which enters the patterned diffuser, so that a planar illumination surface can be positioned such that at least a portion of light emitted from each of said first, second, third, fourth and fifth lighting devices travels in a direction substantially perpendicular to said illumination surface, and;

at least 75 percent of light that passes through the first patterned diffuser projects onto said illumination surface an illuminated first square area on said surface defined by a first line segment, a second line segment, a third line segment and a fourth line segment;

at least 75 percent of light that passes through the second patterned diffuser projects onto said illumination surface an illuminated second square area on said surface defined by said first line segment, a fifth line segment, a sixth line segment and a seventh line segment;

at least 75 percent of light that passes through the third patterned diffuser projects onto said illumination surface an illuminated third square area on said surface defined by said second line segment, an eighth line segment, a ninth line segment and a tenth line segment;

at least 75 percent of light that passes through said fourth patterned diffuser projects onto said illumination surface an illuminated fourth square area on said surface defined by said third line segment, an eleventh line segment, a twelfth line segment and a thirteenth line segment;

at least 75 percent of light that passes through said fifth patterned diffuser projects onto said illumination surface an illuminated fifth square area on said surface defined by said fourth line segment, a fourteenth line segment, a fifteenth line segment and a sixteenth line segment.

22. A method as recited in claim 21, wherein said first lighting device comprises at least one solid state light emitter.

23. A method as recited in claim 21, wherein at least some light emitted by a light source in said first lighting device enters said first patterned diffuser through a first surface of said first patterned diffuser and exits said first patterned diffuser through a second surface of said first patterned diffuser.

24. A method as recited in claim 23, wherein a plurality of optical features are on said first surface of said first patterned diffuser.

25. A method of lighting comprising:

illuminating first, second, third, fourth, fifth, sixth and seventh lighting devices so that each of said first, second, third, fourth, fifth, sixth and seventh lighting devices emits light in a lighting assembly,

light from said first lighting device entering a first patterned diffuser,

light from said second lighting device entering a second patterned diffuser,

light from said third lighting device entering a third patterned diffuser,

light from said fourth lighting device entering a fourth patterned diffuser,

light from said fifth lighting device entering a fifth patterned diffuser,

light from said sixth lighting device entering a sixth patterned diffuser,

light from said seventh lighting device entering a seventh patterned diffuser,

each of said patterned diffusers comprising a plurality of optical features configured to cause at least 75% of light that enters the patterned diffuser to exit the patterned diffuser to produce a hexagonal pattern of light, regardless of the pattern of the light which enters the patterned diffuser, so that a planar illumination surface can be positioned such that at least a portion of light emitted from each of said first, second, third, fourth, fifth, sixth and seventh lighting devices travels in a direction substantially perpendicular to said illumination surface, and;

at least 75 percent of light that passes through the first patterned diffuser projects onto an illumination surface an illuminated first hexagonal area on said surface defined by a first line segment, a second line segment, a third line segment, a fourth line segment, a fifth line segment and a sixth line segment;

at least 75 percent of light that passes through the second patterned diffuser projects onto said illumination surface an illuminated second hexagonal area on said surface defined by the first line segment, a seventh line segment, an eighth line segment, a ninth line segment, a tenth line segment and an eleventh line segment;

at least 75 percent of light that passes through the third patterned diffuser projects onto said illumination surface an illuminated third hexagonal area on said surface defined by the second line segment, the eleventh line segment, a twelfth line segment, a thirteenth line segment, a fourteenth line segment and a fifteenth line segment;

at least 75 percent of light that passes through the fourth patterned diffuser projects onto said illumination surface an illuminated fourth hexagonal area on said surface defined by the third line segment, the fifteenth line segment, a sixteenth line segment, a seventeenth line segment, an eighteenth line segment and a nineteenth line segment;

at least 75 percent of light that passes through the fifth patterned diffuser projects onto said illumination surface an illuminated fifth hexagonal area on said surface defined by the fourth line segment, the nineteenth line segment, a twentieth line segment, a twenty-first line segment, a twenty-second line segment and a twenty-third line segment;

at least 75 percent of light that passes through the sixth patterned diffuser projects onto said illumination surface an illuminated sixth hexagonal area on said surface defined by the fifth line segment, the twenty-third line segment, a twenty-fourth line segment, a twenty-fifth line segment, a twenty-sixth line segment and a twenty-seventh line segment;

at least 75 percent of light that passes through the seventh patterned diffuser projects onto said illumination surface an illuminated seventh hexagonal area on said surface defined by the sixth line segment, the seventh line segment, the twenty-seventh line segment, a twenty-eighth line segment, a twenty-ninth line segment and a thirtieth line segment.

26. A method as recited in claim 25, wherein said first lighting device comprises at least one solid state light emitter.

27. A method as recited in claim 25, wherein at least some light emitted by a light source in said first lighting device enters said first patterned diffuser through a first surface of said first patterned diffuser and exits said first patterned diffuser through a second surface of said first patterned diffuser.

28. A method as recited in claim 27, wherein a plurality of optical features are on said first surface of said first patterned diffuser.

29. A method of lighting comprising:

illuminating first, second, third, fourth, fifth, sixth, seventh, eighth and ninth lighting devices so that each of said first, second, third, fourth, fifth, sixth, seventh, eighth and ninth lighting devices emits light in a lighting assembly,

light from said first lighting device entering a first patterned diffuser,

light from said second lighting device entering a second patterned diffuser,

light from said third lighting device entering a third patterned diffuser,

light from said fourth lighting device entering a fourth patterned diffuser,

light from said fifth lighting device entering a fifth patterned diffuser,

light from said sixth lighting device entering a sixth patterned diffuser,

light from said seventh lighting device entering a seventh patterned diffuser,

light from said eighth lighting device entering an eighth patterned diffuser,

light from said ninth lighting device entering a ninth patterned diffuser,

each of said first, third, fifth, seventh and ninth patterned diffusers comprising a plurality of optical features configured to cause at least 75% of light that enters the patterned diffuser to exit the patterned diffuser to produce an octagonal pattern of light, regardless of the pattern of the light which enters the patterned diffuser, and each of said second, fourth, sixth and eighth patterned diffusers comprising a plurality of optical features configured to cause at least 75% of light that enters the patterned diffuser to exit the patterned diffuser to produce a square pattern of light, regardless of the pattern of the light which enters the patterned diffuser, so that a planar illumination surface can be positioned such that at least a portion of light emitted from each of said first, second, third, fourth, fifth, sixth, seventh, eighth and ninth lighting devices travels in a direction substantially perpendicular to said illumination surface, and;

at least 75 percent of light that passes through the first patterned diffuser projects onto said illumination surface an illuminated first octagonal area on said surface defined by a first line segment, a second line segment, a third line segment, a fourth line segment, a fifth line segment, a sixth line segment, a seventh line segment and an eighth line segment;

at least 75 percent of light that passes through the second patterned diffuser projects onto said illumination surface an illuminated first square area on said surface defined by said first line segment, a ninth line segment, a tenth line segment and an eleventh line segment;

at least 75 percent of light that passes through the third patterned diffuser projects onto said illumination surface an illuminated second octagonal area on said surface defined by the second line segment, the eleventh line segment, a twelfth line segment, a thirteenth line segment, a fourteenth line segment, a fifteenth line segment, a sixteenth line segment and a seventeenth line segment;

at least 75 percent of light that passes through the fourth patterned diffuser projects onto said illumination surface an illuminated second square area on said surface defined by the third line segment, the seventeenth line segment, an eighteenth line segment and a nineteenth line segment;

at least 75 percent of light that passes through the fifth patterned diffuser projects onto said illumination surface an illuminated third octagonal area on said surface defined by the fourth line segment, the nineteenth line segment, a twentieth line segment, a twenty-first line segment, a twenty-second line segment, a twenty-third line segment, a twenty-fourth line segment and a twenty-fifth line segment;

at least 75 percent of light that passes through the sixth patterned diffuser projects onto said illumination surface an illuminated third square area on said surface defined by the fifth line segment, the twenty-fifth line segment, a twenty-sixth line segment and a twenty-seventh line segment;

at least 75 percent of light that passes through the seventh patterned diffuser projects onto said illumination surface an illuminated fourth octagonal area on said surface defined by the sixth line segment, the twenty-seventh line segment, a twenty-eighth line segment, a twenty-ninth line segment, a thirtieth line segment, a thirty-first line segment, a thirty-second line segment and a thirty-third line segment;

at least 75 percent of light that passes through the eighth patterned diffuser projects onto said illumination surface an illuminated fourth square area on said surface defined by the seventh line segment, the thirty-third line segment, a thirty-fourth line segment and a thirty-fifth line segment;

at least 75 percent of light that passes through the ninth patterned diffuser projects onto said illumination surface an illuminated fifth octagonal area on said surface defined by the eighth line segment, the ninth line segment, the thirty-fifth line segment, a thirty-sixth line segment, a thirty-seventh line segment, a thirty-eighth line segment, a thirty-ninth line segment and a fortieth line segment.

30. A method as recited in claim 29, wherein said first lighting device comprises at least one solid state light emitter.

31. A method as recited in claim 29, wherein at least some light emitted by a light source in said first lighting device enters said first patterned diffuser through a first surface of said first patterned diffuser and exits said first patterned diffuser through a second surface of said first patterned diffuser.

32. A method as recited in claim 31, wherein a plurality of optical features are on said first surface of said first patterned diffuser.