Patent Description:
Conventionally, a light-emitting depilation device that removes hair by irradiating the hair with light has been known. The light-emitting depilation device irradiates the skin surface of a user with light at a specific wavelength to promote hair removal by causing the light to act on melanin in hair follicles. As the light-emitting depilation device, for example, an apparatus such as that disclosed in Patent Literature <NUM> has been known.

Patent Literature <NUM> discloses a light-emitting depilation device including a light source that emits treatment light and detection light that are to be incident on an object, a photodetector that detects the detection light for detecting the object, and a control unit for controlling the light source. The control unit determines an absorption of the detection light from the detected detection light, and controls the light source so as to generate the treatment light based on the determined absorption. The treatment light has a wavelength within the range of <NUM> to <NUM>, an energy density within the range of <NUM> J/cm<NUM> to <NUM> J/cm<NUM>, and a pulse duration within <NUM> to <NUM>.

The conventional light-emitting depilation device controls the application of light based on the characteristics of the object to be irradiated with the light. However, the conventional light-emitting depilation device might emit light even when the light-emitting depilation device is not fully in contact with the object. For example, the light may be emitted even when depilation device is in partial contact with the object, the partial contact being a condition in which a portion provided with the light detector is in contact with the object but another portion provided with the light source and on the opposite side of the light detector is separated from the object. In such a condition, a large amount of light may leak from the space between the light-emitting depilation device and the object, and the leaked light may get into the eyes of a user. In addition, the conventional light-emitting depilation device, which controls the application of light based on the characteristics of the object, may cause inflammation on the skin if the object is irradiated with treatment light having high irradiation energy.

The present disclosure provides a light-emitting depilation device capable of suppressing leakage of light or inflammation of the skin.

A light-emitting depilation device according to an aspect of the present disclosure includes a light source, a skin cooling unit, and a push switch. The light source emits light having a wavelength of <NUM> or longer and <NUM> or shorter. The skin cooling unit faces the light source, transmits the light emitted from the light source, and cools skin upon coming into contact with the skin. The push switch includes a pressing unit surrounding an outer periphery of the light source and the skin cooling unit. When the pressing unit is not being pressed, the pressing unit is protruding from a surface of the skin cooling unit, the surface being a surface that is to be brought into contact with the skin, toward an opposite side of the light source with respect to the skin cooling unit. When the pressing unit is pressed, a surface pressed by the skin moves closer to the light source, with respect to the skin cooling unit. The push switch is configured to switch the light source to emit light and not to emit light to cause the light source to keep emitting the light at least for a part of time while the pressing unit is pressed, and not to emit the light while the pressing unit is not pressed.

According to the present disclosure, it is possible to achieve a light-emitting depilation device capable of suppressing leakage of light or inflammation of the skin.

An exemplary embodiment will now be explained in detail with reference to some drawings. Note that descriptions more in detail than necessary are sometimes omitted. For example, detailed descriptions of already well-known matters and redundant descriptions of substantially the same configurations may be omitted.

Note that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

In the following exemplary embodiment, up-down direction Z is defined for light-emitting depilation device <NUM> by establishing a light outlet as upside, and the side facing the opposite side of the outlet as downside. Furthermore, in the explanation hereunder, one of horizontal directions extending along light-emitting depilation device <NUM> is defined as a width direction Y, and the direction orthogonal to up-down direction Z and width direction Y is defined as front-back direction X.

Light-emitting depilation device <NUM> according to the present exemplary embodiment will now be explained with reference to <FIG>.

<FIG> is a cross-sectional view illustrating a configuration of light-emitting depilation device <NUM> according to the present exemplary embodiment, and <FIG> is a cross-sectional view taken along line II-II of <FIG>. As illustrated in <FIG> and <FIG>, light-emitting depilation device <NUM> includes housing <NUM>, light source <NUM>, temperature sensor <NUM>, skin cooling unit <NUM>, push switch <NUM>, cooler <NUM>, and controller <NUM>.

One end of housing <NUM> has an opening serving as a light outlet of light-emitting depilation device <NUM>. Light source <NUM> is provided inside the opening of housing <NUM>, and emits light toward skin S of a person. Housing <NUM> has a bottom on the opposite side of light source <NUM>. Housing <NUM> has a plurality of first openings <NUM> and a plurality of second openings <NUM>. The outer air is collected through the plurality of first openings <NUM>, and the air is discharged through the plurality of second openings <NUM>. Light source <NUM>, temperature sensor <NUM>, skin cooling unit <NUM>, push switch <NUM>, cooler <NUM>, and controller <NUM> are housed inside housing <NUM>.

<FIG> is a perspective view illustrating an example of a schematic arrangement of light source <NUM> according to the present exemplary embodiment. In <FIG>, some structures such as temperature sensor <NUM>, skin cooling unit <NUM>, push switch <NUM>, and cooler <NUM> are omitted. As illustrated in <FIG>, in the present exemplary embodiment, light source <NUM> includes a plurality of LEDs (light-emitting diodes). The LEDs are mounted on substrate <NUM> at substantially equal intervals therebetween. Light source <NUM> is electrically connected to a power supply (not illustrated). Light source <NUM> emits light by receiving the supply power from the power supply.

Light source <NUM> emits light having a wavelength of <NUM> or longer and <NUM> or shorter. By irradiating skin S with the light as described above, melanin in hair follicles absorbs the light, and becomes heated. This heat damages the hair matrix in the hair follicle, and promotes removal of the hair. The wavelength of the light may be <NUM> or longer, <NUM> or longer, <NUM> or longer, or <NUM> or longer. The wavelength of the light may be <NUM> or shorter or <NUM> or shorter. The light emitted from light source <NUM> may be light having a peak wavelength within a range between <NUM> or longer and <NUM> or shorter. Even with the light having a peak wavelength within such a range, emitted light may include a wavelength component outside this range. In addition, all of the LEDs do not need to have the same wavelength spectrum, and LEDs emitting light at different wavelength spectra may be used in combination. The wavelength is a wavelength of light emitted from light source <NUM> at a temperature of <NUM>.

Light source <NUM> preferably emits the light with an irradiance condition of <NUM> W/cm<NUM> or higher and <NUM> W/cm<NUM> or lower. By irradiating the hair with light at an irradiance of <NUM> W/cm<NUM> or higher, a high depilatory effect can be given to the hair during an initial growth period to a growth period. By emitting the light at an irradiance of <NUM> W/cm<NUM> or lower, it is possible to suppress an increase in the skin temperature due to the exposure to the light. Therefore, skin S is cooled more reliably, and irritations of the skin can be reduced. The irradiance may be <NUM> W/cm<NUM> or higher, <NUM> W/cm<NUM> or higher, or <NUM> W/cm<NUM> or higher. The irradiance may be <NUM> W/cm<NUM> or lower or <NUM> W/cm<NUM> or lower.

In the present exemplary embodiment, the light emitted from light source <NUM> is pulsed light that is intermittently emitted. Light source <NUM> preferably emits light intermittently with a condition of irradiation time of <NUM> or longer and <NUM> or shorter. By exposing the hair to light for <NUM> or longer, a high depilatory effect can be given to the hair during an initial growth period to a growth period. In addition, by setting the exposure to the light to <NUM> or shorter, it is possible to suppress an increase in the skin temperature due to the exposure to the light. Therefore, skin S is cooled more reliably, and irritations of the skin can be reduced. The irradiation time may be <NUM> or longer. The irradiation time may be <NUM> or shorter or <NUM> or shorter.

The energy of each pulse of the light emitted from light source <NUM> is preferably <NUM> J/cm<NUM> or higher and <NUM> J/cm<NUM> or lower. By setting the energy to <NUM> J/cm<NUM> or higher, a high depilatory effect can be achieved. In addition, in light-emitting depilation device <NUM> including skin cooling unit <NUM>, by setting the energy to <NUM> J/cm<NUM> or lower, it is possible to suppress an increase in the skin temperature due to the exposure to the light. Therefore, skin S is cooled more reliably, and irritations of the skin can be reduced.

Skin cooling unit <NUM> is disposed at a position facing light source <NUM>. Skin cooling unit <NUM> may be in contact with light source <NUM>, or may be disposed spaced from light source <NUM>. Skin cooling unit <NUM> is provided in a manner coming into contact with skin S on the side opposite to light source <NUM>. Skin cooling unit <NUM> is made of a translucent material. When light is emitted from light source <NUM>, skin cooling unit <NUM> transmits the light emitted from light source <NUM>, and skin S is irradiated with the light having passed through skin cooling unit <NUM>. Skin cooling unit <NUM> is, for example, a translucent plate, and in the present exemplary embodiment, disk-shaped skin cooling unit <NUM> is used.

Skin cooling unit <NUM> is preferably made of a material that does not absorb much of the light emitted from light source <NUM>. Specifically, the total light transmittance of skin cooling unit <NUM> is preferably <NUM>% or higher. By setting the total light transmittance to <NUM>% or higher, skin cooling unit <NUM> can transmit most of the light emitted from light source <NUM>. Therefore, a large amount of light can be delivered to the melanin, and the depilatory effect can be promoted. In addition, because the amount of light absorbed and converted into heat by skin cooling unit <NUM> can be reduced, a temperature rise in skin cooling unit <NUM> can be suppressed. From the viewpoint of suppressing absorption of the light by skin cooling unit <NUM>, the total light transmittance is preferably <NUM>% or higher, still more preferably <NUM>% or higher, and particularly preferably <NUM>% or higher. The upper bound of the total light transmittance is <NUM>%. The total light transmittance can be measured according to JIS K7361-<NUM>:<NUM>.

The refractive index of skin cooling unit <NUM> is preferably <NUM> or higher. By setting the refractive index of skin cooling unit <NUM> to <NUM> or higher, skin cooling unit <NUM> does not absorb much of the light emitted from light source <NUM>. When the refractive index is higher, skin cooling unit <NUM> transmits a greater amount of light. Therefore, the refractive index is more preferably <NUM> or higher, still more preferably <NUM> or higher, and particularly preferably <NUM> or higher. The upper bound of the refractive index is not particularly limited, but may be <NUM>. The refractive index can be measured by a minimum deviation method according to JIS B7071-<NUM>:<NUM>.

Skin cooling unit <NUM> cools skin S upon coming into contact with skin S. Skin cooling unit <NUM> preferably includes a material having high thermal conductivity. The thermal conductivity of skin cooling unit <NUM> is preferably <NUM> W/mK or higher. By setting the thermal conductivity to <NUM> W/mK or higher, even when skin cooling unit <NUM> becomes heated by the light from light source <NUM> and skin S, the heat is dissipated easily. Therefore, skin S can be cooled effectively. The cooling effect of skin cooling unit <NUM> tends to increase by setting the thermal conductivity higher, because skin cooling unit <NUM> becomes more thermally conductive. Therefore, from the viewpoint of cooling efficiency, the thermal conductivity of skin cooling unit <NUM> is more preferably <NUM> W/mK or higher, still more preferably <NUM> W/mK or higher, particularly preferably <NUM> W/mK or higher, and most preferably <NUM> W/mK or higher. The upper bound of the thermal conductivity is not particularly limited, but may be <NUM>,<NUM> W/mK. The thermal conductivity can be measured by a laser flash method according to JIS R1611:<NUM>.

Skin cooling unit <NUM> may contain an inorganic substance. Specifically, skin cooling unit <NUM> preferably includes at least one selected from the group consisting of Al<NUM>O<NUM>, ZnO, ZrO<NUM>, MgO, GaN, AlN, and diamond. Because these materials have a high refractive index and a high thermal conductivity, translucency and thermal conductivity of skin cooling unit <NUM> can be improved. Al<NUM>O<NUM> (sapphire) has a refractive index of <NUM> and a thermal conductivity of <NUM> W/mK. ZnO has a refractive index of <NUM> and a thermal conductivity of <NUM> W/mK. ZrO<NUM> has a refractive index of <NUM> and a thermal conductivity of <NUM> W/mK. MgO has a refractive index of <NUM> and a thermal conductivity of <NUM> W/mK. GaN has a refractive index of <NUM> and a thermal conductivity of <NUM> W/mK. AlN has a refractive index of <NUM> and a thermal conductivity of <NUM> W/mK. Diamond has a refractive index of <NUM> and a thermal conductivity of <NUM> W/mK.

Skin cooling unit <NUM> may contain resin such as a silicone resin, from the viewpoint of heat resistance and translucency. Skin cooling unit <NUM> may also include resin such as silicone resin, and highly thermal conductive filler that is dispersed in the resin. By including such highly thermal conductive filler in skin cooling unit <NUM>, the heat of skin cooling unit <NUM> is dissipated more quickly, so that skin S can be cooled effectively. The highly thermally conductive filler may contain an inorganic substance such as those listed above.

The proportion of the inorganic substance in skin cooling unit <NUM> is preferably <NUM> mass% or higher. By setting the proportion of the inorganic substance in skin cooling unit <NUM> to <NUM> mass% or higher, the thermal conductivity of skin cooling unit <NUM> can be improved. The proportion of the inorganic substance in skin cooling unit <NUM> is more preferably <NUM> mass% or higher, still more preferably <NUM> mass% or higher, particularly preferably <NUM> mass% or higher, and most preferably <NUM> mass% or higher.

Skin cooling unit <NUM> is preferably cooled to -<NUM> or higher and <NUM> or lower. By cooling skin cooling unit <NUM> to -<NUM> or higher, it is possible to cool skin S without causing much pain in skin S by cooling. By cooling skin cooling unit <NUM> to <NUM> or lower, it is possible to suppress inflammation due to a rise in the skin temperature due to the exposure to the irradiation. Skin cooling unit <NUM> is more preferably cooled to <NUM> or higher, still more preferably <NUM> or higher, and particularly preferably <NUM> or higher. In addition, skin cooling unit <NUM> is more preferably cooled to <NUM> or lower, still more preferably <NUM> or lower, particularly preferably <NUM> or lower, and most preferably <NUM> or lower.

Temperature sensor <NUM> detects the temperature of skin cooling unit <NUM>. By detecting the temperature of skin cooling unit <NUM>, the temperature of skin cooling unit <NUM> can be controlled precisely. Temperature sensor <NUM> is provided in a manner facing skin cooling unit <NUM>. Specifically, temperature sensor <NUM> is provided on substrate <NUM>. In the present exemplary embodiment, temperature sensor <NUM> includes a contact temperature sensor. Examples of the contact type temperature sensor include a thermistor, a thermocouple, and a resistance thermometer bulb.

Push switch <NUM> is a momentary switch. Push switch <NUM> is provided on connecting part <NUM> of cooler <NUM>. In front-back direction X and width direction Y, push switch <NUM> is disposed outer side of light source <NUM> and skin cooling unit <NUM>, and is provided in a manner surrounding light source <NUM> and skin cooling unit <NUM>. Push switch <NUM> includes two base portions <NUM> and pressing unit <NUM>.

Two base portions <NUM> are fixed on connecting part <NUM>, on the outer side of holder <NUM> of cooler <NUM> in such a manner that light source <NUM> and skin cooling unit <NUM> are disposed between base portions <NUM> in width direction Y. Each base portion <NUM> has a quadrangular prism shape extending upward from connecting part <NUM>.

Pressing unit <NUM> is engaged with base portions <NUM>, and moves in the up-down directions Z by being pressed by skin S. Pressing unit <NUM> covers the outer periphery of light source <NUM> and skin cooling unit <NUM>. Pressing unit <NUM> includes two first components <NUM> and one second component <NUM>.

Each first component <NUM> has a columnar shape extending upward in up-down direction Z from corresponding base portion <NUM>, and is provided at substantially center in front-back direction X and width direction Y of corresponding base portion <NUM>. Each second component <NUM> is disposed so as to be in contact with a surface of first component <NUM>, the surface facing opposite side of base portion <NUM>. Second component <NUM> has a through-hole at the center in front-back direction X and width direction Y, and has a donut-like shape extending in up-down direction Z. Light source <NUM> and skin cooling unit <NUM> are disposed inside the through-hole of second component <NUM>. A part of a surface of second component <NUM> protrudes upward in up-down direction Z from the surface of skin cooling unit <NUM>, the surface facing on the opposite side of light source <NUM>. In the present exemplary embodiment, first component <NUM> and second component <NUM> are different components that are separated from each other, but pressing unit <NUM> may be one component that is integrally and continuously formed. In addition, the numbers of base portions <NUM>, first components <NUM>, and second components <NUM> are not particularly limited, and may be changed as appropriate.

When pressing unit <NUM> is not being pressed, pressing unit <NUM> is protruding from a surface of skin cooling unit <NUM>, the surface being a surface to be brought into contact with the skin S, in the direction opposite to light source <NUM> with respect to skin cooling unit <NUM> (upward direction in up-down direction Z). Each of base portion <NUM> and pressing unit <NUM> has an internal contact, not illustrated. Push switch <NUM> is configured in such a manner that, while pressing unit <NUM> is not pressed, the contact inside base portion <NUM> is not brought into contact with the contact inside pressing unit <NUM>, and open the circuit to which light source <NUM> is connected. When pressing unit <NUM> is pressed, the surface thereof being pressed by skin S moves toward light source <NUM> (downward in up-down direction Z), with respect to skin cooling unit <NUM>. Therefore, the contact provided inside base portion <NUM> is brought into contact with the contact provided inside pressing unit <NUM>, and close the circuit to which light source <NUM> is connected.

An elastic body, not illustrated, is provided between base portions <NUM> and pressing unit <NUM>. When pressing unit <NUM> is pressed, the elastic body becomes elastically deformed, and pushes back pressing unit <NUM> by the elastic force generated by the elastic deformation. Therefore, when the force pressing pressing unit <NUM> is removed, the elastic body acts on pressing unit <NUM> and brings pressing unit <NUM> back to the original position, and the surface of pressing unit <NUM> that is in contact with skin S moves in a direction separating from base portion <NUM> (upward in up-down direction Z).

Push switch <NUM> switches to cause light source <NUM> to emit light and not to emit light in such a manner that light source <NUM> emits light during at least some of the time while pressing unit <NUM> is pressed, and light source <NUM> does not to emit light while pressing unit <NUM> is not pressed. This configuration, therefore, enables skin S to be irradiated with light during at least some of the time while light-emitting depilation device <NUM> is pressed against skin S, and stops the light emission when light-emitting depilation device <NUM> is separated from skin S.

The light emission may be started immediately after push switch <NUM> is pressed, or may be started a predetermined time elapses from when push switch <NUM> is pressed. The timing at which light source <NUM> starts the light emission may be controlled by controller <NUM>. Light-emitting depilation device <NUM> may also cause light source <NUM> to emit light after skin S comes into contact with the surface of skin cooling unit <NUM>. In this manner, skin surface having been cooled is irradiated with light. In this manner, heating of skin S is suppressed, so that it is possible to suppress irritation of skin S. In addition, because skin S is irradiated with light while held in contact with skin cooling unit <NUM>, unevenness in the irradiation can be reduced, so that stable depilatory effect can be achieved.

Cooler <NUM> cools skin cooling unit <NUM>. Because light-emitting depilation device <NUM> includes cooler <NUM>, the temperature of skin cooling unit <NUM> can be further reduced. Therefore, the skin cooling effect by skin cooling unit <NUM> can be further improved. Cooler <NUM> includes heat sink <NUM> and air blower <NUM>.

Heat sink <NUM> is connected to skin cooling unit <NUM>, and dissipates the heat skin cooling unit <NUM> is deprived of. Heat sink <NUM> includes connecting part <NUM>, holder <NUM>, and heat sink fins <NUM>.

Connecting part <NUM> is a plate-like member. On a first surface that is one surface of the connecting part <NUM>, substrate <NUM> is provided. Substrate <NUM> is smaller than connecting part <NUM>, and is provided to fit inside connecting part <NUM>. Holder <NUM> and push switch <NUM> are connected to the outer side of substrate <NUM>, on the first surface of connecting part <NUM>. Heat sink fins <NUM> are provided on a second surface, that is the surface on the opposite side of the first surface of connecting part <NUM>.

Holder <NUM> protrudes upward in up-down direction Z from the first surface of connecting part <NUM>, and holds the entire periphery of skin cooling unit <NUM>. Therefore, light source <NUM> is covered by skin cooling unit <NUM>, holder <NUM>, and connecting part <NUM>. The heat generated by light source <NUM> is dissipated via skin cooling unit <NUM> and heat sink <NUM> of cooler <NUM>. While holder <NUM> holds the entire periphery of skin cooling unit <NUM>, holder <NUM> may be connected to at least a part of skin cooling unit <NUM>.

Heat sink fins <NUM> are provided on the second surface of connecting part <NUM> (surface facing opposite side of light source <NUM>). Therefore, holder <NUM> and connecting part <NUM> transfers the heat from skin cooling unit <NUM> to heat sink fins <NUM>. Heat sink fins <NUM> include a plurality of fins, and has a large contact area with air, so that heat is dissipated quickly.

Heat sink <NUM> preferably contains material having excellent thermal conductivity. The thermal conductivity of heat sink <NUM> may be higher than that of skin cooling unit <NUM>. Specifically, heat sink <NUM> may contain metal such as aluminum, iron, or copper. Holder <NUM>, connecting part <NUM>, and heat sink fins <NUM> may be made of the same material or may be made of different materials.

Air blower <NUM> cools heat sink <NUM> by sending the air to heat sink <NUM>. Air blower <NUM> includes, for example, a fan, and when the fan is rotated, an air flow is generated. Housing <NUM> has a plurality of first openings <NUM> at positions facing air blower <NUM>. Housing <NUM> has a plurality of second openings <NUM> at positions facing heat sink fins <NUM>. Therefore, when air blower <NUM> is driven, the air collected from the outside of housing <NUM> through the plurality of first openings <NUM> is sent to heat sink fins <NUM>. The heat of the air having been brought into contact with heat sink fins <NUM> is exchanged with the heat of the heat sink fins <NUM>, and heat sink fins <NUM> are cooled thereby. The air heated by coming into contact with heat sink fins <NUM> is released outside of housing <NUM> via the plurality of second openings <NUM>.

Explained in the present exemplary embodiment is an example in which light-emitting depilation device <NUM> uses air cooler <NUM> to cool skin cooling unit <NUM>, but a Peltier element or the like may also be used to cool skin cooling unit <NUM>, in addition to air cooler <NUM>, or instead of air cooler <NUM>. When a Peltier element is used to cool skin cooling unit <NUM>, light-emitting depilation device <NUM> can cool skin cooling unit <NUM> much more intensely.

<FIG> is a control block diagram related to controller <NUM>. Controller <NUM> controls light source <NUM> to emit light and not to emit light. Controller <NUM> controls to drive and to stop air blower <NUM>. As illustrated in <FIG>, temperature sensor <NUM> and push switch <NUM> are connected on the input side of controller <NUM>. On the output side of controller <NUM>, light source <NUM> and cooler <NUM> are connected. Controller <NUM> includes a computer system that includes a central processing unit (CPU), a read-only memory (ROM), and a random access memory (RAM). When the CPU executes a program stored in the ROM, the computer system functions as controller <NUM>. In the example explained herein, the program executed by the CPU is recorded on the ROM included in the computer system in advance, but may also be provided by being recorded in a non-transitory recording medium such as a memory card, or be provided over a telecommunication line such as the Internet.

Controller <NUM> keeps light source <NUM> on or blinking while push switch <NUM> is being pressed. Controller <NUM> may cause light source <NUM> to emit light at the same time as push switch <NUM> is pressed, or may cause light source <NUM> to emit light after a predetermined time elapses from when push switch <NUM> is pressed.

Controller <NUM> may also be configured to cause cooler <NUM> to cool skin cooling unit <NUM> so as to bring the temperature of skin cooling unit <NUM> to -<NUM> or higher and <NUM> or lower. Controller <NUM> may also be configured to receive a signal related to the temperature of skin cooling unit <NUM> from temperature sensor <NUM>, and to drive cooler <NUM> to cool skin cooling unit <NUM> based on the signal. Controller <NUM> may also be configured to cool skin cooling unit <NUM> by controlling the output of air blower <NUM>, for example. Furthermore, controller <NUM> may also be configured to cool skin cooling unit <NUM> by controlling the output of the Peltier element, for example. Specifically, controller <NUM> may drive the Peltier element when the temperature of skin cooling unit <NUM> becomes <NUM> or higher, and may stop driving the Peltier element when the temperature of skin cooling unit <NUM> drops to a level lower than -<NUM>.

An action and effects achieved by light-emitting depilation device <NUM> having the configuration described above will be explained below.

It will be now explained, with reference to <FIG>, how light-emitting depilation device <NUM> emits light. <FIG> is a cross-sectional view illustrating a configuration before light-emitting depilation device <NUM> is used. <FIG> is a cross-sectional view illustrating a configuration before push switch <NUM> of light-emitting depilation device <NUM> is pressed. <FIG> is a cross-sectional view illustrating a configuration after push switch <NUM> of light-emitting depilation device <NUM> is pressed. <FIG> is a cross-sectional view illustrating a configuration while skin S is exposed to the light of light-emitting depilation device <NUM>.

As illustrated in <FIG>, before light-emitting depilation device <NUM> is used, push switch <NUM> remains unpressed. Therefore, pressing unit <NUM> of push switch <NUM> is protruding from the surface of skin cooling unit <NUM> that is to be brought into contact with skin S, toward the opposite side of light source <NUM> with respect to skin cooling unit <NUM>. In this condition, light source <NUM> is not emitting light.

As illustrated in <FIG>, during the use of light-emitting depilation device <NUM>, light-emitting depilation device <NUM> is pressed against skin S of a user. Pressing unit <NUM> of push switch <NUM> is protruding from the skin contact surface of skin cooling unit <NUM>. Therefore, push switch <NUM> first comes into contact with skin S of the user, and light source <NUM> becomes covered by skin S and push switch <NUM>.

As illustrated in <FIG>, push switch <NUM> is pressed by coming into contact with skin S. Specifically, when pressing unit <NUM> of push switch <NUM> is pressed, the surface being pressed by skin S moves closer to light source <NUM>, with respect to skin cooling unit <NUM>. Skin cooling unit <NUM> therefore then comes into contact with skin S, with light source <NUM> covered by skin S and push switch <NUM>. Skin cooling unit <NUM> then becomes sealed by skin S. By being brought into contact with skin cooling unit <NUM>, skin S is cooled.

As illustrated in <FIG>, push switch <NUM> closes the circuit to which light source <NUM> is connected, and cause the light source <NUM> to emit light. Because skin cooling unit <NUM> is sealed by skin S, and light source <NUM> is also covered by push switch <NUM>, skin S is irradiated with the light emitted from light source <NUM> with no leakage. In order to bring skin cooling unit <NUM> and skin S into contact with each other more reliably, light source <NUM> may be caused to emit light after a predetermined time elapses from when pressing unit <NUM> of push switch <NUM> is pressed.

As described above, light-emitting depilation device <NUM> according to the present exemplary embodiment includes light source <NUM>, skin cooling unit <NUM>, and push switch <NUM>. Light source <NUM> emits light having a wavelength of <NUM> or longer and <NUM> or shorter. Skin cooling unit <NUM> is positioned facing light source <NUM>, transmits the light emitted from light source <NUM>, and cools skin S upon coming into contact with skin S. Push switch <NUM> includes pressing unit <NUM> surrounding the outer periphery of light source <NUM> and the skin cooling unit <NUM>. When pressing unit <NUM> is not being pressed, pressing unit <NUM> is protruding from the surface of skin cooling unit <NUM>, the surface being a surface that is to be brought into contact with skin S, toward the opposite side of light source <NUM> with respect to skin cooling unit <NUM>. When pressing unit <NUM> is pressed, its surface being pressed by the skin S moves closer to light source <NUM>, with respect to skin cooling unit <NUM>. Push switch <NUM> switches to cause light source <NUM> to emit light and not to emit light in such a manner that light source <NUM> emits light during at least a part of the time while pressing unit <NUM> is pressed, and light source <NUM> does not to emit light while pressing unit <NUM> is not pressed.

Thus, light-emitting depilation device <NUM> can irradiate skin S with the light, with light source <NUM> covered by push switch <NUM> and skin S. Therefore, light-emitting depilation device <NUM> can suppress leakage of light. Light-emitting depilation device <NUM> can also cause skin cooling unit <NUM> to cool skin S by coming into contact with skin S at the time of light emission. Therefore, light-emitting depilation device <NUM> can suppress inflammation of skin S.

Light-emitting depilation device <NUM> may be light-emitting depilation device <NUM> including the skin cooling unit (skin cooling unit <NUM>), in which the LED (light source <NUM>) emits light after the top surface of the skin cooling unit (skin cooling unit <NUM>) is pushed against the skin (skin S) and comes into contact with the skin (skin S). Even with such light-emitting depilation device <NUM>, it is possible to suppress leakage of light or inflammation of skin S.

As light-emitting depilation device <NUM> according to the present exemplary embodiment, light source <NUM> may emit light after surface of skin S comes into contact with skin cooling unit <NUM>.

In this manner, light-emitting depilation device <NUM> irradiates the skin S with the light while the surface of skin S is being cooled. The temperature rise of skin S is thus suppressed more reliably, so that light-emitting depilation device <NUM> can alleviate irritation of skin S. In addition, because skin S is irradiated with light while skin cooling unit <NUM> is held in contact with skin S, light-emitting depilation device <NUM> can suppress uneven irradiation of light, and achieve the depilatory effect stably.

As in light-emitting depilation device <NUM> according to the present exemplary embodiment, light source <NUM> may include an LED.

By using the LED as light source <NUM>, the height of light-emitting depilation device <NUM> can be reduced, so that light-emitting depilation device <NUM> can be downsized. In addition, because LEDs are generally small, the space between the LED and skin cooling unit <NUM> in light-emitting depilation device <NUM> can be reduced. Therefore, light-emitting depilation device <NUM> can dissipate the heat generated by the LED not only via connecting part <NUM> of skin cooling unit <NUM> but also via skin cooling unit <NUM>. Therefore, because light-emitting depilation device <NUM> can deplete the heat generated by the LED from around the LED, the LED can be cooled effectively.

As in light-emitting depilation device <NUM> according to the present exemplary embodiment, skin cooling unit <NUM> may be cooled to -<NUM> or higher and <NUM> or lower.

As a result, light-emitting depilation device <NUM> can cool skin S without causing much pain in skin S by cooling, and can suppress inflammation due to a rise in the skin temperature due to the exposure to the irradiation.

As in light-emitting depilation device <NUM> according to the present exemplary embodiment, the total light transmittance of skin cooling unit <NUM> may be <NUM>% or higher.

In this manner, skin cooling unit <NUM> can transmit most of the light emitted from light source <NUM>. Therefore, light-emitting depilation device <NUM> can deliver a large amount of light to the melanin, and can promote the depilatory effect. In addition, because light-emitting depilation device <NUM> can reduce the amount of light absorbed and converted into heat by skin cooling unit <NUM>, a temperature rise in skin cooling unit <NUM> can be suppressed.

As in light-emitting depilation device <NUM> according to the present exemplary embodiment, skin cooling unit <NUM> may include at least one selected from the group consisting of Al<NUM>O<NUM>, ZnO, ZrO<NUM>, MgO, GaN, AlN, and diamond.

In this manner, light-emitting depilation device <NUM> can improve translucency and thermal conductivity of skin cooling unit <NUM>. Therefore, light-emitting depilation device <NUM> can promote the depilatory effect, and enhance the cooling effect of skin cooling unit <NUM>.

As in light-emitting depilation device <NUM> according to the present exemplary embodiment, light source <NUM> may emit light intermittently with a conditions of irradiance of <NUM> W/cm<NUM> or higher and <NUM> W/cm<NUM> and irradiation time of <NUM> or longer and <NUM> or shorter.

In this manner, light-emitting depilation device <NUM> can achieve high depilatory effect on hair during an initial growth period to a growth period. In addition, light-emitting depilation device <NUM> can cool skin S more reliably, and can reduce irritation of the skin.

As described above, the above exemplary embodiment has been described as an example of the technology in the present disclosure. However, the technique in the present disclosure is not limited thereto, and can also be applied to exemplary embodiments in which changes, replacements, additions, omissions, and the like are made. Therefore, other exemplary embodiments will be described below.

Light-emitting depilation device <NUM> according to the above exemplary embodiment has been described to include light source <NUM> that includes an LED, as an example. However, light source <NUM> only needs to be able to emit light having a wavelength of <NUM> or longer and <NUM> or shorter. Light source <NUM> is not limited to an LED, and may include, for example, a xenon lamp, a laser diode, and a combination thereof. With the use of an LED as light source <NUM>, however, the size of light-emitting depilation device <NUM> can be reduced, as mentioned above.

Skin cooling unit <NUM> may include a wavelength cut filter that suppresses transmission of a specific wavelength. The wavelength cut filter may be provided, for example, on a surface of skin cooling unit <NUM> on the side facing light source <NUM> or the surface facing the opposite side of light source <NUM>. In particular, when a xenon lamp is used as light source <NUM>, light at various wavelengths is emitted, Therefore, by cutting light having a specific wavelength, for example, it is possible to suppress pain in skin S. Furthermore, by enabling to the light at a specific wavelength to be taken out, light-emitting depilation device <NUM> including skin cooling unit <NUM> that includes the wavelength cut filter can also improve the depilatory effect.

Skin cooling unit <NUM> may also include an antireflection film for preventing reflection of the light emitted from light source <NUM>. The antireflection film may be provided on a surface of skin cooling unit <NUM> on the side facing light source <NUM>, for example. By providing such an antireflection film to skin cooling unit <NUM>, reflection of light is suppressed, and light-emitting depilation device <NUM> including skin cooling unit <NUM> including the antireflection film can irradiate skin S with a larger amount of light.

In addition, light-emitting depilation device <NUM> according to the above exemplary embodiment has been explained to cool skin cooling unit <NUM> using cooler <NUM>, as an example. However, when the thermal conductivity of skin cooling unit <NUM> is high, it is not always necessary to cool skin cooling unit <NUM> using cooler <NUM>, because the heat dissipation of skin cooling unit <NUM> is high.

Light-emitting depilation device <NUM> according to the above exemplary embodiment is explained to include cooler <NUM> that is connected to skin cooling unit <NUM> to cool skin cooling unit <NUM>, as an example. However, cooler <NUM> does not need to be connected to skin cooling unit <NUM>.

Note that, because the above-described exemplary embodiments are intended to illustrate the technique in the present disclosure, various changes, replacements, additions, omissions, and the like can be made within the scope of the claims and equivalents thereof.

Claim 1:
A light-emitting depilation device comprising:
a light source (<NUM>) configured to emit light having a wavelength of <NUM> or longer and <NUM> or shorter;
a skin cooling unit (<NUM>) that faces the light source, is configured to transmit the light emitted from the light source, and to cool
skin upon coming into contact with the skin; and
a push switch (<NUM>) that includes a pressing unit (<NUM>) surrounding an outer periphery of the light source and the skin cooling unit, wherein
when the pressing unit is not being pressed, the pressing unit protrudes from a surface of the skin cooling unit toward an opposite side of the light source with respect to the skin cooling unit, the surface of the skin cooling unit being a surface that is to be brought into contact with the skin,
when the pressing unit (<NUM>) is pressed by the skin, a surface of the pressing unit is pressed by the skin to be moved toward the light source with respect to the skin cooling unit, and
the push switch switches the light source to emit the light and not to emit the light to cause the light source to keep emitting the light at least for a part of time while the pressing unit is pressed, and not to emit the light while the pressing unit is not pressed.