Thursday, January 31, 2013

LED Lighting - The Future?

Source: NY Times

The quintessential symbol of an idea is the incandescent light bulb. No less a purveyor of ideas than the US Patent and Trademark Office (USPTO) pushes a lightbulb icon to the tab on your browser when you visit their web pages and a flag embossed lightbulb as the logo for the America Invents Act. Director David Kappos displays one of Thomas Edison’s original light bulb models in his office. The incandescent light bulb was a truly disruptive and transformative invention that has been used by billions of people worldwide.

The US Energy Information Administration (USEIA) estimates that in 2012 US residential and commercial lighting used 13 and 20 percent, respectively, of the electricity purchased in those energy use sectors (USEIA Annual Energy Outlook 2013 Early Release, reference case). Thus, lighting represents a major opportunity for reducing energy use via technological changes (e.g., compact fluorescent bulbs, LEDs, automated controls), behavioral changes (e.g., energy conservation programs), or government laws and regulations that incrementally ban the manufacture and sale of a more than century-old lighting technology.

The USPTO Green Tech Pilot Program issued a significant number of lighting-related patents. We’ll look at some of those representative of inventions by one of the dominant assignees in the program.

LG Innotek

LG Innotek (011070:Korea SE), headquartered in Seoul, Korea, was “the first general electronic component company in Korea”, according to the company’s web page. The company manufactures and sells LED lighting, printed circuit boards, mobile devices such as digital camera modules, electronic display components, network and automotive devices.

Some LED Patents

Three patents are representative of some of LG Innotek’s LED technology.

The Single LED Package

Light emitting diodes (LED) are semiconductors that convert electricity into light. Once used almost exclusively as indicator lighting for electronics, solid state LED lighting is a rapidly emerging technology that continues to move into the mainstream of general purpose illumination technology.

Early energy inventions in lighting, and specifically light emitting diode technology, reach back to 1907. LEDs operate based on electroluminescence — where a material emits light in response to an electrical current or a strong electric field. The phenomenon was discovered in 1907 by British researcher H. J. Round.

Source: USPTO Green Technology Program Discovery and Analysis Report, Way Better Patents.

A good example of a typical LED is found in LG Innotek’s US 8,039,863 patent, ‘Light emitting device’, issued on October 18, 2011. The single inventor is Bum Chul Cho.

Claim 1 is a concise summary of the invention:

A light emitting device comprising:

a package body comprising a trench;
a first electrode and a second electrode on and/or in the package body;
a wire electrically connected to the second electrode;
a light emitting diode on the first electrode, the light emitting diode being electrically connected to the second electrode through the wire; and
a lens on the package body and covering the wire, wherein at least one of the first electrode and the second electrode extends up to a bottom surface of the package body via the trench disposed in the uppermost surface of the package body.

Many multiples of these individual packages make up LEDs you might purchase in your local big-box store, in stop lights (that in winter have difficulty in snowy weather because they don’t generate sufficient heat to melt snow and ice. There are always unintended consequences; for example, (see our post patentECO - The Unintended Consequences of Inventions) or that would be found in the next two patents below.

A LED With Sand

Patent US 8,115,369, ‘Lighting device’, issued on February 14, 2012 to Seok Jin Kang and three co-inventors. Filed on November 8, 2010, its three-year plus prosecution was significantly longer than the 19.7 month average from the program up to that point (a detailed review of pendency under this demo ‘economically important technology’ program may be found in Way Better Patents Discovery and Analysis Report.)

Claim 1 shows the use of the major component of sand in a heat transfer pad between the light emitting substrate and a heat sink:

A lighting device comprising:

a substrate;
a light emitting device disposed on the substrate;
a heat sink to radiate heat from the light emitting device;
and a pad being interposed between the substrate and the heat sink and transferring heat generated from the light emitting device to the heat sink and comprising silicon of 10 to 30 wt° A, a filler of 70 to 90 wt %, glass fiber of 2 to 7 wt % in terms of weight percent (wt %), wherein the light emitting device includes an LED.

The sand-based (i.e., silicon) heat transfer pad and heat sink are necessary to reduce heat generated from the device.

A LED for Your Shop

How many of you have ceiling mounted multiple-tube fluorescent light fixtures in your kitchen, garage, workshop, rec room (does anyone have those anymore, or have they all become ‘media rooms’?), office, or store? LG has a light for you.

Patent US 8,109,647, also entitle ‘Lighting device’, issued on February 7, 2012 to Kim Dong Soo and Kim Yun Ha. This patent issued in less than 18 months, faster than the Green Tech program average pendency.

Claim 11 provides a good summary of the invention:

A lighting device comprising:

a case comprising:

a bottom plate;
walls extending from ends of the bottom plate; and
louvers coupled to and inclined from respective edges of the walls;
a light emitter coupled to the bottom plate;
a diffuser plate spaced apart from the light emitter and disposed between the walls, and a reflector, disposed on an inner surface of the case, to reflect light emitted from the light emitter and to direct the reflected light through the diffuser plate, wherein each of the louvers is oriented at an obtuse angle relative to the diffuser plate and wherein the light emitter includes an LED.

Market Opportunity

Other companies in the LED innovation space include Cree, Philips, Osram, and GE among others. They are aware of the great market potential of LED lighting, as described by the US Department of Energy:

Widespread use of LED lighting has the greatest potential impact on energy savings in the United States. By 2027, widespread use of LEDs could save about 348 TWh (compared to no LED use) of electricity: This is the equivalent annual electrical output of 44 large electric power plants (1000 megawatts each), and a total savings of more than $30 billion at today’s electricity prices.

That’s a good thing, because recent USEPA regulations caused the retirement of more than 9,000 MW of coal-fired power plants in the US in 2012 and could eventually lead to the closing of almost 35,000 MW of coal electricity generation.