Skin comprises epidermis, dermis, and subcutaneous adipose tissue. Since if cosmetics are applied to the skin, the epidermis, i.e., the upper layer of the skin, recognizes the cosmetics as a toxin and hinders absorption of the cosmetics due to the influence of molecular size, bio characteristics, biochemical phenomena, and the like, the amount of cosmetics practically absorbed into the skin is very small.
Accordingly, an iontophoresis method has been developed to increase absorption of cosmetics, medicines, or the like into the skin. The iontophoresis method is a method of allowing micro current to flow through the skin thereby absorbing effective components contained in the medicines or cosmetics having electric charges into the skin by electrical repulsive force. Such an iontophoresis method can be used so that vitamin C, which is a skin whitening effect material, is absorbed into the skin to eliminate liver spots or skin anti-aging materials is absorbed into the skin to suppress occurrence of wrinkles. Also, it has been known that the method is considerably effective.
Presently, iontophoresis apparatuses are marketed, which use a method of inducing electric fields to be formed around the skin by attaching patches allowing micro current to flow to the cheekbone area under the eyes after applying cosmetic components having superior antioxidant and skin protecting functions to the whole face.
However, such iontophoresis means are mainly manufactured as a disposable mask or patch having electrodes and batteries therein, so that the manufacturing costs are increased. Furthermore, since current intensity is fixed, there is a problem in that a side effect can occur if the current intensity is too high, and any effect cannot be obtained at all if the current is too low.
In order to solve the problems, disclosed in Korean Patent No. 610252 is a battery unit, which is detachably mounted to an electrode attached to skin of a user and comprises a battery housing for receiving batteries and an electric circuit capable of adjusting intensity of current so as to increase the amount of active materials absorbed into the skin of the user.
However, although such a battery unit can be detachably mounted to the electrode and save manufacturing costs, it is inconvenient in that skin condition of a user should be measured using a separate skin condition diagnosing apparatus in order to adjust current intensity in accordance with the skin condition of the user, and there is a problem in that whether the current flows constantly while the user uses the battery unit cannot be monitored.