Kawasaki, Japan, November 17, 2014

Fujitsu Laboratories Ltd. today announced the development of a technology that can embed ID data in light cast by LEDs or other light sources onto objects, and also recover this ID data from objects that have been lit in this way.

By embedding data in light in a way that it is not detectable to the naked eye, an object that has been illuminated can convey data to a smartphone or other smart device. With previous technologies, data could only be conveyed to a user's area, but with this technology, data can be conveyed at the level of an individual object. To capture the data, a user only needs to point a camera at the object. This technology enables products in a store, works of art, people, buildings and a variety of other objects to be the source of data transmission.

In recent years, the widespread ownership of smart devices and increasing prevalence of data transmission environments created to offer access to the cloud have made searches for information related to an object, even while being at the very site of the object, a commonplace occurrence, no matter what the time or place. Some existing technologies for linking a variety of physical objects with network services include NFC tags and QR codes, where identifying information is directly affixed to the object. Another technology is based on tying information services to the location, rather than the object itself, such as by using the global positioning system (GPS), or other methods based on Bluetooth, ultrasound, or visible light communication carried via radio waves, sound, or light.

Technological Issues

Physically affixing identifying data to an object can diminish the appearance of the object itself. This and the limited range of devices supporting that technology have previously been issues. Conversely, using the object's location means data can only be distributed to an area, such as a section of a store, for example. This made it difficult to distribute more granular information to individual objects, such as about whatever product or exhibit is in front of the user.

Fujitsu Laboratories has developed a technology that modulates the color of light emitted by LED lights in such a way as to be undetectable to the human eye, but that can still embed ID data in the light that is cast on an object.

Information embedded using color modulations

Color LEDs combine the three lights of red, green, and blue (RGB) to produce a range of colors. By modulating the intensity of the light emitted by each of the three component colors along the time axis, ID data can be embedded in the light cast onto an object, even with very small variations.

Data for one ID is attached to each individual LED light.

Reflectance compensation
When light is cast onto a surface, some of it will be absorbed and some reflected, depending on the reflectivity of that surface. The signal encoded in the respective RGB wavelengths will wind up being weakened by that partial absorption, and since this technology uses an image captured by a camera to measure the reflectivity and compensate accordingly, information-capturing accuracy has been improved.

Figure 2: How reflectance compensation improves accuracy

Results

This technology enables ID data to be embedded in an object that had been illuminated, where it can then be captured simply by pointing at the object with a smartphone, for example. The smartphone can then capture the data corresponding to the ID. This could be used as part of the following services:

 - Providing product information just by pointing a smartphone at the product, and in the future, it may even be possible to handle automated payment and delivery.

- Streaming briefing video just by pointing a smartphone at an exhibit in a museum.

 - Just by pointing a smartphone at a performer on stage, downloading the song the performer is singing.

 - Displaying detailed information or commentary in the user's native language just by pointing a smartphone at a historical building or plaque at a tourist destination.

In addition, this technology is not limited to LED lighting, and could also be used with projectors.

This technology will be exhibited at Fujitsu Forum 2014, running November 19-20 in Munich, Germany.