A SELECTIVE PHOTOTHERMOLYSIS EPILATION DEVICE Field of the Invention

The present invention relates to a selective photothermolysis epilation device using ultra high power LED matrix. Background of the Invention

Epilation is a process applied for removal of hair on the skin. Primary principle of epilation is selective photothermolysis (SPTL). In this technique, a specific wavelength of light and the pulse duration are matched to obtain optimal effect on the targeted tissues with minimal effect on the surrounding tissues.

Generally lasers are used in the process of epilation and these lasers can cause localized damage by selectively heating the dark target matter (i.e. melanin) in the area that causes hair growth. Since the light emitted by the laser is absorbed by dark objects, the laser light can be absorbed by the dark materials in the skin (chromophore) rapidly and intensely.

Melanin which is mentioned above as the dark target matter is the primary chromophore for all epilation lasers. Melanin occurs naturally in the skin and gives skin and hair their color. There are two types of melanin in hair. "Eumelanin" gives hair brown or black color, while "Pheomelanin" gives hair blonde or red color. Epilation can be performed only for black and brown (dark and coarse) hair due to selective absorption of laser light photons. Light skin and dark hair are an ideal combination and the most effective results are achieved with this combination. In the conventional method, the pain resulting from epilation varies depending on the amount of energy that is applied to the skin with each laser/light pulse, because the areas containing chromophore are destroyed at 50 - 60°C and the energy delivered to the skin upon reaching this temperature causes discomfort for the patient. Conventional bulk heating methods enable to raise the temperature of the roots and the surrounding area to the therapeutic temperature; however cause intense pain due to the high energy delivered in a single pulse.

Devices which perform epilation and treatment for spots and acne/wrinkles, skin treatments, etc. by using LEDs instead of lasers are provided below.

United States patent document no. US2010219736, an application in the state of the art, discloses a device using LED (light emitting diodes) for therapeutic purposes. LED chips are used in the device and the said chips are bonded to the tip of the heat pipe. The device is used for spot, ace/wrinkle, skin treatments.

United States patent document no. US6645230, an application in the state of the art, discloses a device which utilizes LED beam for a photodynamic therapy by using a therapeutic light source. The device can be used for cosmetic treatments such as stain removal, epilation, hair restoration, skin rejuvenation, wrinkle/acne treatment; and for treatment of oncological and non-oncological skin diseases (actinic/solar keratoses, Bowen's disease, superficial basal cell carcinoma, squamous cell carcinoma, MF, T-cell lymphoma, acne and seborrhoea, eczema, psoriasis, etc.).

Chinese document no. CN102784437, an application in the state of the art, discloses a device using LED (light emitting diodes) light which is employed in the field of health care. Flexible linear LED chips are used in the device. Acne treatments and skin treatments are performed by using blue LED light in the device. Problems Solved by the Invention

The objective of the present invention is to provide an epilation device wherein ultra high power LED matrix is used instead of laser diode. Thus, by using LED matrix containing LEDs that radiate to a wide area contrary to the lasers, the effect on the hair at the points where the light beams emitted by the LEDS overlap is increased and thereby treatment time is reduced.

In the epilation device of the present invention, preferably LEDs operating at a wavelength of 810 nm are used and the applications that can be performed by these LEDs are shown below;

- Epilation

- Treatment of damaged and wounded skin

- Skin softening

- Treatment for dry and rough skin

- Treatment for large pores, fine wrinkles and redness

- Treatment for freckles, reduced skin elasticity and dull skin

- Skin rejuvenation

- Reducing pain

- Increasing blood circulation

Detailed Description of the Invention

An epilation device developed to fulfill the objective of the present invention is illustrated in the accompanying figures wherein,

Figure 1. is a schematic view of the epilation device.

Figure 2. a) is a top view of the LED matrix.

b) is a top view of the surface illuminated by the LED matrix. Figure 3. is a representative view showing the light beams sent by the LED matrix to the skin and the overlap of these light beams on the hair follicles.

Figure 4. is a schematic view of the epilation device which is portable and cordless.

The components in the figures are given reference numbers as follows:

1. Epilation device

2. Rectifier

3. Display unit

4. Control unit

5. LED matrix

6. First cooler

7. Second cooler

8. Battery

Al. Area where there is a single light beam

A2. The area where the light beams sent by two LEDs intersect

A3. The area where the light beams sent by three LEDs intersect

The epilation device (1) of the present invention which enables to remove the hair on the skin basically comprises

at least one rectifier (2) which converts alternating current to direct current,

at least one display unit (3) on which the settings (adjustments) made via a user interface are displayed;

at least one control unit (4) which is adapted to perform the commands input via the display unit (3),

at least one LED matrix (5), which enables to remove hair by radiating at a specific wavelength to a wide area that encompasses the hair follicles as well, and which includes a plurality of LEDs thereon, at least one first cooler (6) which enables to cool the LEDs in the LED matrix (5),

at least one second cooler (7) which enables to cool the skin which is heated by the LED matrix (5).

In a preferred embodiment of the invention, the epilation device (1) is operated by being connected to the mains voltage. The alternating current coming from the mains is converted to direct current by means of an AC/DC rectifier (2) thereby providing the direct current required for operation of the control unit (4) and the LED matrix (5).

Settings of the epilation device (1) are touch-operated via the display unit (3) and/or performed by various keys provided on the epilation device (1). By means of the said display unit (3) or the keys, settings such as adjustment of the intensity of the light to be emitted by the LEDs according to the sensitive areas of the skin, skin tone and hair color can be changed. These settings are transmitted to the LED matrix (5) by the control unit (4).

In one embodiment of the invention, the control unit (4) can be any device such as a microprocessor, microcontroller, FPGA, ASIC, etc.

The LED matrix (5) includes LEDs which employ "flip-chip" technology and which preferably operate at a wavelength of 810 nm. The LED matrix (5) formed by using 20x33 LEDs and the surface area affected by the light emitted by the LED matrix (5) in one embodiment of the invention are illustrated in Figure 2a and Figure 2b, respectively.

By means of the said LED matrix (5), light beam is sent not only to an area where there are hair follicles like laser diodes do, but to a wide area also encompassing these hair follicles. This grid method, which is applied in this treatment, and which, in addition to reducing treatment time, significantly improves treatment results by enabling all of the hair follicles to absorb energy. Each LED on the LED matrix (5) forms a conical light beam at a certain wavelength, and depending on the distance of the LED matrix (5) to the skin, these two or more conical areas may overlap with each other. Thus, the effect of the overlapping light beams on the hair follicles is increased.

In a preferred embodiment of the invention, the hair follicles are damaged not by a single high energy pulse, but by repetitive pulses. Thus, the multiple individual pulses that raise the temperature of the dermis to the level needed to prevent hair growth do not cause any burns on the skin or sensation of pain. Duration and temperature of these individual pulses are regulated by the commands, which are adjusted by means of the display unit (3) or various keys and are sent by the control unit (4) to the LED matrix (5). To this end, the control unit (4) increases the temperature of the dermis above 42°C for an effective epilation, but not above 50°C, which may cause pain, burns, and permanent skin discoloration.

In a preferred embodiment of the invention, the first cooler (6) which enables to cool the LEDs on the LED matrix (5) is a liquid cooling system comprising a radiator and fan. In this system, a radiator through which a liquid (e.g. water) passes is connected to the LED chips, and the radiator and thus the heated liquid in the radiator are enabled to be cooled by means of a fan.

In an alternative embodiment of the invention, the first cooler (6) is preferably in the form of a "heat sink", and upon contacting the lower part of the lower base of the LED chip preferably produced from aluminum nitrate ceramic, takes the heat of this LED chip upon itself and performs cooling preferably by means of a fan. Cooling rate varies depending on the surface area that contacts with air. In one embodiment of the invention, in order for the temperature at the lower base of the LED chip to pass to the first cooler (6) more rapidly, in other words in order to increase thermal conductivity, a thermal paste or oil can be used between the lower base of the LED chip and the first cooler (6). In one embodiment of the present invention, the second cooler (7) is located on the epilation device (1) and blows air at approximately -15°C to the skin preferably by a fan in order to cool the skin that is heated during epilation.

In an alternative embodiment of the invention, the epilation device (1) is a portable and cordless device. In the said embodiment, an AC/DC rectifier (2) is not used; instead the epilation device is operated by at least one battery (8) directly providing DC power. The said battery (8) is a battery (8) which is charged on the device. The power received from the batteries (8) supply energy for the control unit (4), LED matrix (5), first cooler (6) and the second cooler (7). Again in this embodiment of the present invention, settings of the intensity of the light to be emitted by the LEDs made according to the sensitive areas of the skin, skin tone and hair color and similar other adjustments can be made by means of a display unit (3) or buttons provided on the cordless epilation device (1).