US 7,520,642 B2
High-density illumination system
Robert L. Holman, Evanston, Ill. (US); and Arthur Cox, Park Ridge, Ill. (US)
Assigned to Digital Optics International Corporation, Evanston, Ill. (US)
Filed on Apr. 05, 2007, as Appl. No. 11/784,046.
Application 11/784046 is a continuation of application No. 11/089314, filed on Mar. 23, 2005, granted, now 7,210,806.
Application 11/089314 is a continuation of application No. 10/763816, filed on Jan. 22, 2004, granted, now 6,871,982.
Claims priority of provisional application 60/442624, filed on Jan. 24, 2003.
Prior Publication US 2007/0211449 A1, Sep. 13, 2007
Int. Cl. F21V 5/00 (2006.01)
U.S. Cl. 362—328  [362/19; 362/245; 362/331; 362/800; 349/61] 14 Claims
OG exemplary drawing
 
1. An illuminating system, comprising:
an electrical interconnection system for interconnecting at least one LED light emitting element to a power source;
at least one LED light emitting element positioned on a common light-emitting plane;
a first light redirecting element disposed above the at least one LED light-emitting element on said common light emitting plane, each said first light redirecting element including at least one diffusing medium, a diffusing layer, and a component, said component selected from the group consisting of a metallically reflecting bin and a lens system, said metallically reflecting bin having a circular or rectangular cross-section with mathematically curving shape necessitated by meeting the geometrical relationship between input and output aperture sizes, AinSin 2θin=AoutSin2θout, where
Ainis:
if circular, the area of the reflecting bin inlet πrin2, rin being the radius of the bin's inlet opening, and
if rectangular, (xin)(yin)
θin is the maximum half-angle emitted by the at least one LED at bin's input opening disposed above it, the full beam angle being 2θin,
Aout is the area of the aperture existing at the bin's ideal height H given as
if circular, H=(rin+rout)/Tanθout with rout being the diameter of the bin's ideal output aperture, and θout is the corresponding output beam's half-angle, the beam's full angle being 2θout;
if rectangular, H being the larger of H1=0.5(xin+xout)/Tanθout,x and H2=0.5 (yin+yout)/Tanθout,y with xout and yout being the aperture edge sizes, θout,x and θout,y being the corresponding output beam half-angles in each orthogonal meridians;
and Hbin is the actual bin height of the metallically reflecting bin of the first light redirecting element, Hbin is equal to or less than the ideal bin height H;
a second light redirecting element disposed beyond said first light redirecting element comprised of at least one condensing element having effective focal length F and an elevation above said first light redirecting means in the range 0 to 2 F above the output plane of said first light redirecting layer:
said at least one condensing element of the second light redirecting layer selected from the group consisting of a Fresnel lens, two sequentially stacked Fresnel-type cylindrical lenses where the axes of each form an angle of 90-degrees with each other, a reflecting plane having a circular or rectangular cutout that allows for a substantial portion of the emitted light to pass outwards without change in brightness or angular direction, and two sequentially stacked lenticular lenses where the axes of each form an angle of 90-degrees with each other; and
an output aperture disposed beyond said second light redirecting element, said output aperture containing at least one of a clear window and a spatial light modulator.