초록 ▼

An electronic wristwatch having an LCD for time of day, day of month and month of year, as well as four key switches, includes a photodiode for detecting skin damaging ultraviolet, tanning radiation. The photodiode, a microcomputer, key switches, display and a battery are electrically connected to e

An electronic wristwatch having an LCD for time of day, day of month and month of year, as well as four key switches, includes a photodiode for detecting skin damaging ultraviolet, tanning radiation. The photodiode, a microcomputer, key switches, display and a battery are electrically connected to each other so that in response to activation of the key switches the microcomputer stores signals indicative of the time functions, intensity of the skin damaging ultraviolet radiation instantaneously incident on the photodiode at the time one of the key switches is activated, skin type of a subject wearing the watch, subject sun protection factor, and elapsed time from the time one of the key switches is activated, and the remaining time the subject skin can be safely exposed to the skin damaging radiation. The remaining time indication is derived independently of accumulated radiation incident on the photodiode which need not be pointed at the radiation source except when the one key is activated. The remaining time indication can be modified by subsequently pointing the detector at the radiation source and/or entering a different sun protection factor.

대표청구항 ▼

Apparatus for indicating the amount of time skin of a subject can be safely exposed to skin damaging ultraviolet radiation comprising a detector for said radiation, means for deriving indications of subject skin type and sun protection factor on the subject skin, computer means responsive to said in

Apparatus for indicating the amount of time skin of a subject can be safely exposed to skin damaging ultraviolet radiation comprising a detector for said radiation, means for deriving indications of subject skin type and sun protection factor on the subject skin, computer means responsive to said indications and an instantaneous value of said radiation incident on said detector for initially calculating the length of time the subject skin can be safely exposed to the radiation at a detected instantaneous value thereof, means responsive to said instantaneous detected value and independent of radiation accumulated on said detector for indicating when the length of time the subject skin can be safely exposed has expired, the indicating means being activated independently of accumulated radiation incident on the detector.