A Company in Texas Is Suing Apple Over Alleged Infringement of Patents

A company in Texas is suing Apple over alleged infringement of patents that cover pulse-width modulation control of LEDs. Elsewhere, Cooper has filed another lawsuit against Cree and Ruud, and Relume has filed suits against GE and Leotek.

Tyler, Texas-based LED Tech Development, LLC has filed a patent-infringement lawsuit against Apple, citing four US patents.

In essence, the complaint says that various claims of the patents are infringed by Apple products that utilize pulse-width modulation (PWM) signals to drive LEDs. These products include Apple's iPad 3 tablet and Macbook Pro personal computer.

The first patent-in-suit is US patent no. 6,095,661, entitled "Method and Apparatus for an LED Flashlight." It was issued on August 1, 2000, having been filed in March 1998. This patent is assigned to PPT Vision Inc., but LED Tech Development, LLC is described in the lawsuit as being the "owner by assignment" of all four patents-in-suit.

The other patents are:

• US patent no. 7,393,119 entitled "Method and Apparatus for Constant Light Output Pulsed LED Illumination." This patent issued on July 1, 2008. This and the two patents below have their origins in the original application in March 1998 that became the '661 patent.

• US patent no. 6,808,287 entitled "Method and Apparatus for a Pulsed LED Illumination Source." This patent issued on October 26, 2004.

• US patent no. 6,488,390 entitled "Color-Adjusted Camera Light and Method." This issued on December 3, 2002.

LED Tech Development has also filed lawsuits in recent months against Coleman Company, Home Depot USA, and flashlight maker Mag Instrument Inc.

Although the lawsuit against Apple talks about LED Tech Development being "greatly and irreparably harmed" by Apple's continued (alleged) infringement, the wording of the complaint suggests strongly that LED Tech Development is looking for a healthy licensing fee from the tech giant.

Lawsuits invoking patents dating back to the late 1990s, and concerning the use of PWM to control LEDs, will remind some readers of the controversy that surrounded the patents granted to Color Kinetics (CK). Some critics questioned whether these patents should have been granted at all, since PWM control was already a well-known technique. And LED Tech Development may wish to have a chat with Philips, which now owns all the CK patents.

Cooper vs. Cree and Ruud

In September 2012, Cooper Lighting, LLC filed a complaint against Cree, Inc. and Ruud Lighting. The complaint alleges infringement of US patent no. 8,210,722 entitled "LED Device for Wide Beam Generation," which was issued on July 3, 2012.

Ruud is accused of making and selling LED-based products that infringe one or more claims of the '722 patent, including Ruud's Type II Optics products and Type III Optics products. The complaint also says that "Ruud had knowledge of the '722 patent beginning before its issuance and still proceeded to prepare for and commence infringement of the '722 patent, and continued to do so after issuance of the patent."

Cree is accused of making and selling products that infringe one or more claims of the '722 patent, including "XSP Series LED Streetlights that incorporate Type II Optics products and Type III Optics products."

The patent discusses a method to design a lens that provides the required surface-illumination pattern from a specific energy-distribution pattern of a light source such as an LED array. This is done by defining an estimated optical transfer function for a lens shape, and then refining this model until the projected light pattern matches the pre-defined surface-illumination pattern. This is especially applicable to LED street lights.

The latest complaint adds to the extensive patent dispute between Cree and its subsidiary Ruud on one side, and Cooper and its subsidiary Illumination Management Solutions, Inc. (IMS) on the other.

Lexington Luminance LLC

Lexington Luminance LLC, a company based in Lexington, MA, filed three separate actions in August 2012, one against Osram Sylvania, one against Lighting Science Group Corp. (LSGC) and one against Feit Electric Company.

The complaints allege infringement of US patent no. 6,936,851 entitled "Semiconductor light-emitting device and method for manufacturing same."

The alleged infringing products are Osram Sylvania's 8W A19 LED lamp; LSGC's EcoSmart 8W GP19 and A19 LED lamps; and Feit's 7.5W A19 and Utilitech Pro 7.5W LED lamps.

The patent itself describes methods to reduce the defect density in semiconductor LED layers.

Relume vs. GE, Relume vs. Leotek

Oxford, MI-based Relume Corporation has filed two separate actions, one against Leotek Electronics USA Corp., and one against GE Lighting Solutions LLC.

Both complaints were filed in July 2012 and allege infringement of Reissue 42,161 entitled "Power supply for light emitting diode array." This is a reissue of US patent no. 5,661,645.

The patent relates generally to an apparatus for generating power to an LED array and, in particular, to a power supply for operating LED array traffic signals.

The accused products are GE Lighting Solutions' GTx LED Signal Modules and Leotek's IL3 Series LED Traffic Signal Modules.