Tanner pad

Earlier this spring, I'd vacationed in sun-drenched Spain and developed a thorough tan on my arms. Just a month ago, I had a minor spill on my bike and scraped my elbow. The new healed skin is much lighter, as Señor Sol hasn't yet introduced himself yet. While a long-sleeve shirt is the quickest fix, what if my face had met the asphalt instead of just my elbow? I might have a blotchy mark there too.

I imagine a tanning device that would apply selective UV radiation to light blotches, in cases of scarring. This would be a pad of micro color sensors and UV emitters in a matrix, and controlled by a computer. The pad would have a transparent adhesive to hold it in close, uniform contact with skin.

The sensors will find an average skin color value, and find the regions with high brightness (new skin). Then, the UV emitters will irradiate those high brightness areas with UV sufficient to bring them to the darker color (old skin). The tanning matrix would probably need to be reapplied for a few sessions, to allow for the skin's tanning response. People could rent out the unit for a week or two, like renting a TENS unit to treat pain.

It could get rid of the light band that watch wearers get around their wrist, or even out the despised 'farmers tan.' The pad might apply images or text, if someone wants a temporary 'tan-too.'