Patent application number | Description | Published |
20080315228 | LOW PROFILE SIDE EMITTING LED WITH WINDOW LAYER AND PHOSPHOR LAYER - Low profile, side-emitting LEDs are described that generate white light, where all light is emitted within a relatively narrow angle generally parallel to the surface of the light-generating active layer. The LEDs enable the creation of very thin backlights for backlighting an LCD. In one embodiment, the LED emits blue light and is a flip chip with the n and p electrodes on the same side of the LED. Separately from the LED, a transparent wafer has deposited on it a red and green phosphor layer. The phosphor color temperature emission is tested, and the color temperatures vs. positions along the wafer are mapped. A reflector is formed over the transparent wafer. The transparent wafer is singulated, and the phosphor/window dice are matched with the blue LEDs to achieve a target white light color temperature. The phosphor/window is then affixed to the LED. | 12-25-2008 |
20090045420 | Backlight Including Side-Emitting Semiconductor Light Emitting Devices - Individual side-emitting LEDs are separately positioned in a waveguide, or mounted together on a flexible mount then positioned together in a waveguide. As a result, the gap between each LED and the waveguide can be small, which may improve coupling of light from the LED into the waveguide. Since the LEDs are separately connected to the waveguide, or mounted on a flexible mount, stress to individual LEDs resulting from changes in the shape of the waveguide is reduced. | 02-19-2009 |
20090086508 | Thin Backlight Using Low Profile Side Emitting LEDs - Backlights containing low profile, side-emitting LEDs are described that have improved brightness uniformity. In one embodiment, the backlight comprises a solid transparent lightguide with a plurality of openings in a bottom surface of the lightguide, each opening containing a side-emitting LED. Prisms or other optical features are formed in the top wall of each opening to reflect light in the lightguide towards a light output surface of the lightguide so that the side-emitting LEDs do not appear as dark spots at the output of the backlight. To avoid any direct emission from the sides of the LED toward the output surface of the lightguide appearing as bright areas, optical features are formed at the edges of the opening or in the output surface of the lightguide so that direct emission light is not output from the lightguide. Substantially identical cells may be formed in the lightguide using cellular walls around one or more LEDs. | 04-02-2009 |
20100065864 | WHITE POINT COMPENSATED LEDS FOR LCD DISPLAYS - A backlight for a color LCD includes white light LEDs formed using a blue LED die with a layer of red and green phosphors over it. The attenuation by the LCD layers of the blue light component of the white light is typically greater as the blue wavelength becomes shorter. In order to achieve a uniform blue color component across the surface of an LCD screen and achieve uniform light output from one LCD to another, the blue light leakage of the phosphor layer is tailored to the dominant or peak wavelength of the blue LED die. Therefore, the white points of the various white light LEDs in a backlight should not match when blue LED dies having different dominant or peak wavelengths are used in the backlight. The different leakage amounts through the tailored phosphor layers offset the attenuation vs. wavelength of the LCD layers. | 03-18-2010 |
20100091498 | LOW PROFILE SIDE EMISSION TIR LENS FOR LED - A low profile side-emitting lens for an LED die has two tiers of different waveguides radially extending out from a center side-emitting lens. An LED emits light into the center side-emitting lens, which has a curved surface that internally reflects the LED light outward approximately parallel to the top surface of the LED die. The center lens has a height of 2 mm, required for reflecting the LED light outward. Radially extending from the periphery of the bottom half of the center lens is a bottom tier of waveguides, each having a height of 1 mm, and radially extending from the periphery of the top half of the center lens is a top tier of waveguides, each having a height of 1 mm. The light output areas of the top and bottom tiers of waveguides are parallel with each other so that the 2 mm high side emission is reduced to a 1 mm side emission without reducing the emission area. | 04-15-2010 |
20100109034 | LED WITH MOLDED BI-DIRECTIONAL OPTICS - A double-molded lens for an LED includes an outer lens molded around the periphery of an LED die and a collimating inner lens molded over the top surface of the LED die and partially defined by a central opening in the outer lens. The outer lens is formed using silicone having a relatively low index of refraction such as n=1.33-1.47, and the inner lens is formed of a higher index silicone, such as n=1.54-1.76, to cause TIR within the inner lens. Light not internally reflected by the inner lens is transmitted into the outer lens. The shape of the outer lens determines the side emission pattern of the light. The front and side emission patterns separately created by the two lenses may be tailored for a particular backlight or automotive application. | 05-06-2010 |
20100201916 | THIN BACKLIGHT USING LOW PROFILE SIDE EMITTING LEDS - Backlights containing low profile, side-emitting LEDs are described that have improved brightness uniformity. In one embodiment, the backlight comprises a solid transparent lightguide with a plurality of openings in a bottom surface of the lightguide, each opening containing a side-emitting LED. Prisms or other optical features are formed in the top wall of each opening to reflect light in the lightguide towards a light output surface of the lightguide so that the side-emitting LEDs do not appear as dark spots at the output of the backlight. To avoid any direct emission from the sides of the LED toward the output surface of the lightguide appearing as bright areas, optical features are formed at the edges of the opening or in the output surface of the lightguide so that direct emission light is not output from the lightguide. Substantially identical cells may be formed in the lightguide using cellular walls around one or more LEDs. | 08-12-2010 |
20100207140 | COMPACT MOLDED LED MODULE - A method of forming a light emitting diode (LED) module molds an array of lens support frames over an array of connected lead frames. LEDs are bonded to the lead frame contacts within the support frames. Molded lenses are then affixed over each support frame, and the lead frames are diced to create individual LED modules. In another embodiment, the lenses are molded along with the support frames to create unitary pieces, and the support frames are affixed to the lead frames in the array of connected lead frames. In another embodiment, no lenses are used, and cups are molded with the lead frames so that the LED module is formed solely of the unitary lead frame/cup and the LED. Since each LED enclosure is formed of only one or two separate pieces, and the modules are fabricated on an array scale, the modules can be made very small and simply. | 08-19-2010 |
20100290234 | LED LAMP PRODUCING SPARKLE - A substantially hemispherical lens surrounding an LED die is described that creates a sparkle as an observer views the lens from different angles. The lens is formed of an interconnected array of 100-10,000 or more lenslets. Each lenslet focuses an image of the LED die at an output of the lenslet such that the LED die image area at the output is less than 1/9 the area of the LED die to create a substantially point source image of the LED die at an outer surface of the lens. When the LED die is energized, the shape of each lenslet causes point source images of the LED die to be perceived by an observer at various viewing angles, such that the emitted LED light appears to sparkle and speckle as the observer moves relative to the lens. | 11-18-2010 |