Lighting unit for providing indirect light

Claim 2

A lighting unit adapted to be mounted below eye level for indirect illumination of a work surface comprising a generally elongated bowl-shaped symmetrical reflector having a lower arcuate portion with a sharp radial sweep and a substantially frustoconical upper portion, said reflector having a reflective surface contoured to direct generally upward, in a predetermined pattern, light rays emanating from a light source within said reflector, said light source being centrally disposed with respect to the vertical axis and below the midpoint of said lighting unit, said reflective surface being the circumferential internal wall of said reflector whereby said reflective surface generally directs reflected light rays away from said vertical axis at predetermined angles for reflection by a ceiling surface spaced above said lighting unit to provide for illumination of said work surface and whereby, beyond a maximum predetermined angle, substantially no light rays are reflected from said reflective surface toward said ceiling surface, so that glare interference in the illuminated area is reduced.

Claim 3

A lighting unit according to claim 1 wherein said reflective surface reflects said light rays striking it upward toward said ceiling surface at angles no greater than 65° as measured from said vertical axis, said upper frustoconical portion and lower arcuate portion being contoured to reflect said light rays at said above-mentioned angles by varying the radius with respect to the depth of the reflector as set forth in the table below: ______________________________________ depth from top of radius from vertical reflector (inches) axis (inches) ______________________________________ 0.000 6.078 0.250 ↓ 0.500 ↓ 0.750 ↓ 1.000 ↓ 1.250 ↓ 1.500 ↓ 1.750 ↓ 2.000 ↓ 2.250 ↓ 2.500 ↓ 2.750 ↓ 3.000 frustoconical 3.250 ↑ 3.500 ↑ 3.750 ↑ 4.000 ↑ 4.250 ↑ 4.500 ↑ 4.750 ↑ 5.000 ↑ 5.250 ↑ 5.500 ↑ 5.750 ↑ 6.000 5.015 6.250 4.975 6.500 4.930 6.750 4.875 7.000 4.820 7.250 4.757 7.500 4.680 7.750 4.593 8.000 4.484 8.250 4.359 8.500 4.209 8.750 4.031 9.000 3.835 9.250 3.593 9.500 3.296 9.750 2.953 9.875 2.765 10.000 2.515 10.125 2.234 10.250 1.890 10.375 (INSIDE) 1.469 ______________________________________

Claim 4

A lighting unit according to claim 1 wherein said reflective surface reflects said light rays striking it upward toward said ceiling surface at angles no greater than 65° as measured from said vertical axis, said upper frustoconical portion having first and second frustoconical surfaces, said upper frustoconical portion and lower arcuate portion being contoured to reflect said light rays at said above-mentioned angles by varying the radius with respect to the depth of the reflector as set forth in the table below: ______________________________________ depth from top of radius from vertical reflector (inches) axis (inches) ______________________________________ 0.000 7.375 0.250 ↓ 0.500 ↓ 0.750 ↓ 1.000 ↓ 1.250 ↓ 1.500 ↑ 1.750 ↑ 2.000 ↑ 2.250 frustoconical 2.500 ↑ 2.750 ↑ 3.000 ↑ 3.250 ↑ 3.500 ↑ 3.750 ↑ 4.000 ↑ 4.250 ↑ 4.500 ↑ 4.750 ↑ 5.000 6.796 5.250 ↓ 5.500 ↓ 5.750 ↓ 6.000 ↓ 6.250 ↓ 6.500 frustoconical 6.750 ↑ 7.000 ↑ 7.250 ↑ 7.500 ↑ 7.750 ↑ 8.000 ↑ 8.125 6.234 8.250 6.280 8.500 6.156 8.750 6.098 9.000 6.031 9.250 5.953 9.500 5.875 9.750 5.776 10.000 5.645 10.250 5.550 10.500 5.320 10.750 5.125 11.000 4.880 11.250 4.600 11.500 4.312 11.750 4.000 11.875 3.849 12.000 3.656 12.125 3.473 12.250 3.265 12.375 3.055 12.500 2.805 12.625 2.484 12.750 (INSIDE) 2.094 ______________________________________

Claim 5

A lighting unit according to claims 2, 3 or 1 wherein said lighting unit is adapted to emit maximum light intensity between 0° and 20° of said vertical axis.