Patent Description:
Conventionally, a light irradiation hair removal device that emits light to remove hair is known. The light irradiation hair removal device promotes a discharge of hair by irradiating a skin surface of a user with a light having a specific wavelength and causing the light to act on melanin of hair follicles. As a light irradiation hair removal device, for example, a device as shown in PTL <NUM> is known.

PTL <NUM> discloses a light irradiation hair removal device having a light source that causes a processing light and a sensing light to be incident on a target object, a light detector that detects the sensing light for sensing the target object, and a control unit for controlling the light source. The control unit determines absorption of the sensing light from the detected sensing light, and controls the light source such that the processing light is generated depending on the determined absorption.

PTL <NUM>: <CIT> further relevant prior art is formed by document <CIT>.

A conventional light irradiation hair removal device includes a vertical cavity surface emitting laser (VCSEL) with mutually-independent sub-groups that emit light of different wavelengths. Then, the conventional light irradiation hair removal device controls light turning on and off of these VCSEL in the generation of the processing light dependent on the absorption of the sensing light. In the conventional light irradiation hair removal device, since a part of the mounted VCSEL is turned off to generate the processing light, an irradiance may be lowered and a hair removal effect may be reduced. Further, in the conventional light irradiation hair removal device, in a case where a light having a single wavelength is emitted, a light depth entering the skin becomes constant, and melanocytes containing melanin of the hair follicles existing at a specific depth may be intensively heated. In such a case, uneven heating in a depth direction of the skin occurs, and thus a sufficient hair removal effect may not be obtained.

The present disclosure provides a light irradiation hair removal device capable of uniformly irradiating the entire area of melanocytes distributed in hair follicles with light.

A light irradiation hair removal device according to one aspect of the present disclosure includes a first light source, a second light source, a skin cooling unit, a push switch, a first cooling unit, and a second cooling unit. The first light source emits first light having a wavelength from <NUM> to <NUM> inclusive. The second light source emits second light having a wavelength from <NUM> to <NUM> inclusive. The skin cooling unit faces the first light source and the second light source, transmits the first light emitted from the first light source and the second light emitted from the second light source, and cools a skin when the skin cooling unit comes into contact with the skin. The push switch includes a pressing unit surrounding a periphery of the first light source, the second light source, and the skin cooling unit. In a case where the pressing unit is not pressed, the pressing unit protrudes toward a direction opposite to the first light source and the second light source against the skin cooling unit from a surface of the skin cooling unit in contact with the skin. In a case where the pressing unit is pressed by the skin, a surface pressed by the skin moves toward the direction of the first light source and the second light source against the skin cooling unit. The push switch switches between emission and non-emission of the first light from the first light source and the second light from the second light source. The first light is emitted from the first light source and the second light is emitted from the second light source during at least a part of time while the pressing unit is pressed, and the first light is not emitted from the first light source and the second light is not emitted from the second light source while the pressing unit is not pressed. The first cooling unit cools the first light source. The second cooling unit cools the second light source. By cooling the first light source, the first cooling unit shifts the wavelength of the first light emitted from the first light source to a wavelength different from the wavelength of the second light emitted from the second light source.

According to the present disclosure, it is possible to obtain a light irradiation hair removal device capable of uniformly irradiating the entire area of melanocytes distributed in hair follicles with light.

Hereinafter, exemplary embodiments will be described in detail with reference to the drawings. However, detailed descriptions more than necessary may be omitted. For example, detailed descriptions of already well-known matters or redundant descriptions of substantially the same configuration may be omitted.

Note that, the accompanying drawings and the following description are only presented to help those skilled in the art fully understand the present disclosure, and are not intended to limit the subject matters described in the scope of claims.

Further, in the following exemplary embodiment, up-down direction Z of light irradiation hair removal device <NUM> is defined with an emission port as an upward direction and a direction opposite to the emission port as a downward direction. Further, a direction in a horizontal direction of light irradiation hair removal device <NUM> is defined as width direction Y, and a direction orthogonal to up-down direction Z and width direction Y is defined as front-back direction X.

Hereinafter, light irradiation hair removal device <NUM> according to the present exemplary embodiment will be described with reference to <FIG>.

<FIG> is a cross-sectional view illustrating the configuration of light irradiation hair removal device <NUM> according to the present exemplary embodiment, and <FIG> is a cross-sectional view taken along line II-II in <FIG>. As shown in <FIG> and <FIG>, light irradiation hair removal device <NUM> includes housing <NUM>, first light source <NUM>, second light source <NUM>, first temperature sensor <NUM>, second temperature sensor <NUM>, third temperature sensor <NUM>, skin cooling unit <NUM>, and push switch <NUM>. Furthermore, light irradiation hair removal device <NUM> includes first cooling unit <NUM>, second cooling unit <NUM>, and controller <NUM>.

One end of housing <NUM> is provided with an opening portion serving as a light emission port of light irradiation hair removal device <NUM>. First light source <NUM> and second light source <NUM> are provided in the opening portion of housing <NUM>, and light is emitted on skin S of a person. Further, a bottom portion is formed on a side of housing <NUM> opposite to first light source <NUM> and second light source <NUM>. Housing <NUM> is provided with a plurality of first opening portions <NUM> and a plurality of second opening portions <NUM>, and external air is taken in from the plurality of first opening portions <NUM> and discharged from the plurality of second opening portions <NUM>. Inside housing <NUM>, first light source <NUM>, second light source <NUM>, first temperature sensor <NUM>, second temperature sensor <NUM>, third temperature sensor <NUM>, skin cooling unit <NUM>, push switch <NUM>, first cooling unit <NUM>, second cooling unit <NUM>, and controller <NUM> are accommodated.

<FIG> is a perspective view illustrating an example of a schematic arrangement state of first light source <NUM> and second light source <NUM> according to the present exemplary embodiment. Note that, in <FIG>, configurations of third temperature sensor <NUM>, skin cooling unit <NUM>, push switch <NUM>, and second cooling unit <NUM> are partially omitted. As shown in <FIG>, first light source <NUM> is disposed substantially at a center of substrate <NUM>, and second light source <NUM> is disposed so as to surround first light source <NUM>. In the present exemplary embodiment, first light source <NUM> includes a plurality of light emitting diodes (LED). Further, second light source <NUM> includes a plurality of LEDs. The plurality of LEDs included in first light source <NUM> are mounted on substrate <NUM> in a state of being spaced at substantially equal intervals. Further, the plurality of LEDs included in second light source <NUM> are mounted on substrate <NUM> in a state of being spaced at substantially equal intervals. First light source <NUM> and second light source <NUM> are disposed with a gap larger than a gap between each LED included in first light source <NUM>. First light source <NUM> and second light source <NUM> are electrically connected to a power source (not illustrated), and when power is supplied from the power source, light is emitted from first light source <NUM> and second light source <NUM>.

First light source <NUM> and second light source <NUM> emit light having a wavelength from <NUM> to <NUM> inclusive. When the light as described above is emitted on skin S, melanin of hair follicles absorbs the light and generates heat. Then, hair matrixes included in the hair follicles are damaged by the heat, and a hair discharge is promoted. A wavelength of light may be more than or equal to <NUM>, more than or equal to <NUM>, more than or equal to <NUM>, or more than or equal to <NUM>. Further, a wavelength of light may be less than or equal to <NUM>, or less than or equal to <NUM>. The light emitted from first light source <NUM> and second light source <NUM> may be light having a peak wavelength within a range from <NUM> to <NUM> inclusive. Even in a case where light has a peak wavelength within the range as described above, the emitted light may contain a wavelength component outside the above range. Note that, the wavelength is a wavelength of light emitted in a case where the temperature of first light source <NUM> or second light source <NUM> is <NUM>. Further, types of first light source <NUM> and second light source <NUM> may be the same, and the wavelength of light emitted from first light source <NUM> and the wavelength of light emitted from second light source <NUM> may be the same at a predetermined temperature. Further, first light source <NUM> and second light source <NUM> may use a combination of LEDs that emit light of different wavelengths.

First light source <NUM> and second light source <NUM> preferably emit light under a condition that an irradiance is from <NUM> W/cm<NUM> to <NUM> W/cm<NUM> inclusive. By irradiating the hair with light at an irradiance more than or equal to <NUM> W/cm<NUM>, it is possible to achieve a good hair removal effect on hair from an early growth period to a growth period. Further, by irradiating the skin with light at an irradiance less than or equal to <NUM> W/cm<NUM>, it is possible to suppress a rise in skin temperature due to light irradiation. Therefore, skin S is cooled more reliably, and skin irritation can be reduced. An irradiance may be more than or equal to <NUM> W/cm<NUM>, more than or equal to <NUM> W/cm<NUM>, or more than or equal to <NUM> W/cm<NUM>. Further, an irradiance may be less than or equal to <NUM> W/cm<NUM>, or less than or equal to <NUM> W/cm<NUM>.

In the present exemplary embodiment, the light emitted from first light source <NUM> and second light source <NUM> is pulsed light emitted in an intermittent manner. First light source <NUM> and second light source <NUM> preferably intermittently emit light under a condition that irradiation time is from <NUM> to <NUM> inclusive. By irradiating the hair with light for more than or equal to <NUM>, it is possible to achieve a good hair removal effect on hair from the early growth period to the growth period. Further, by irradiating the skin with light for less than or equal to <NUM>, it is possible to suppress a rise in skin temperature due to light irradiation. Therefore, skin S is cooled more reliably, and skin irritation can be reduced. The irradiation time may be more than or equal to <NUM>. Further, the irradiation time may be less than or equal to <NUM>, or less than or equal to <NUM>.

Energy of each pulsed light emitted from first light source <NUM> and second light source <NUM> is preferably from <NUM> J/cm<NUM> to <NUM> J/cm<NUM> inclusive. When the energy is more than or equal to <NUM> J/cm<NUM>, a good hair removal effect can be achieved. Further, in light irradiation hair removal device <NUM> including skin cooling unit <NUM>, when the energy is less than or equal to <NUM> J/cm<NUM>, a rise in skin temperature due to light irradiation can be suppressed. Therefore, skin S is cooled more reliably, and skin irritation can be reduced.

First temperature sensor <NUM> detects the temperature of first light source <NUM>. First temperature sensor <NUM> is provided on a surface of substrate <NUM> opposite to first light source <NUM> so as to face first light source <NUM> across substrate <NUM>. Then, first temperature sensor <NUM> indirectly measures the temperature of first light source <NUM> by measuring the temperature of substrate <NUM>. In the present exemplary embodiment, first temperature sensor <NUM> includes a thermistor that is a contact temperature sensor. However, first temperature sensor <NUM> is not limited to a thermistor, and may include a contact temperature sensor such as a thermocouple or a resistance temperature detector, or a non-contact temperature sensor such as a radiation thermometer. Further, as long as first temperature sensor <NUM> can detect the temperature of first light source <NUM>, a position provided in first temperature sensor <NUM> is not particularly limited.

Second temperature sensor <NUM> detects the temperature of second light source <NUM>. Second temperature sensor <NUM> is provided on a surface of substrate <NUM> opposite to second light source <NUM> so as to face second light source <NUM> across substrate <NUM>. Then, second temperature sensor <NUM> indirectly measures the temperature of second light source <NUM> by measuring the temperature of substrate <NUM>. In the present exemplary embodiment, second temperature sensor <NUM> includes a thermistor that is a contact temperature sensor. However, second temperature sensor <NUM> is not limited to a thermistor, and may include a contact temperature sensor such as a thermocouple or a resistance temperature detector, or a non-contact temperature sensor such as a radiation thermometer. Further, as long as second temperature sensor <NUM> can detect the temperature of second light source <NUM>, a position provided in second temperature sensor <NUM> is not particularly limited.

Skin cooling unit <NUM> is disposed at a position facing first light source <NUM> and second light source <NUM>. Skin cooling unit <NUM> may be in contact with first light source <NUM> and second light source <NUM>, or may be disposed with a space from first light source <NUM> and second light source <NUM>. Further, skin cooling unit <NUM> is provided so as to be in contact with skin S on a side opposite to first light source <NUM> and second light source <NUM>. Skin cooling unit <NUM> is made of a material having translucency. When first light source <NUM> and second light source <NUM> emit light, skin cooling unit <NUM> transmits light emitted from first light source <NUM> and second light source <NUM>, and skin S is irradiated with light transmitted through skin cooling unit <NUM>. Skin cooling unit <NUM> is, for example, a plate having translucency, and in the present exemplary embodiment, skin cooling unit <NUM> of a disk is used.

Skin cooling unit <NUM> is preferably made of a material that is unlikely to absorb light emitted from first light source <NUM> and second light source <NUM>. Specifically, a total light transmittance of skin cooling unit <NUM> is preferably more than or equal to <NUM>%. When the total light transmittance is more than or equal to <NUM>%, most of light emitted from first light source <NUM> and second light source <NUM> can be transmitted through skin cooling unit <NUM>. Therefore, a large amount of light can reach melanin, which can promote the hair removal effect. Further, since the amount of light absorbed by skin cooling unit <NUM> and converted into heat can be reduced, a temperature rise of skin cooling unit <NUM> can be suppressed. From a viewpoint of making it difficult for skin cooling unit <NUM> to absorb light, the total light transmittance is more preferably more than or equal to <NUM>%, still more preferably more than or equal to <NUM>%, and particularly preferably more than or equal to <NUM>%. An upper limit value of the total light transmittance is <NUM>%. The total light transmittance can be measured according to JIS K7361-<NUM>:<NUM>.

A refractive index of skin cooling unit <NUM> is preferably more than or equal to <NUM>. When the refractive index of skin cooling unit <NUM> is more than or equal to <NUM>, light from first light source <NUM> and second light source <NUM> is not easily absorbed by skin cooling unit <NUM>. Skin cooling unit <NUM> becomes easier to transmit light as the refractive index value increases. Therefore, the refractive index is more preferably more than or equal to <NUM>, still more preferably more than or equal to <NUM>, and particularly preferably more than or equal to <NUM>. The upper limit value of the refractive index is not particularly limited, but may be <NUM>. The refractive index can be measured by minimum deviation method according to JIS B7071-<NUM>:<NUM>.

Skin cooling unit <NUM> cools skin S when it comes into contact with skin S. Skin cooling unit <NUM> preferably includes a material having a high thermal conductivity. A thermal conductivity of skin cooling unit <NUM> is preferably more than or equal to <NUM> W/mK. When the thermal conductivity is more than or equal to <NUM> W/mK, even when skin cooling unit <NUM> is heated by light from first light source <NUM> and second light source <NUM> and skin S, heat is easily dissipated, and thus skin S can be effectively cooled. As a value of the thermal conductivity increases, the thermal conductivity of skin cooling unit <NUM> tends to increase, and a cooling effect of skin cooling unit <NUM> tends to be better. Therefore, from a viewpoint of cooling efficiency, the thermal conductivity of skin cooling unit <NUM> is more preferably more than or equal to <NUM> W/mK, still more preferably more than or equal to <NUM> W/mK, particularly preferably more than or equal to <NUM> W/mK, and most preferably more than or equal to <NUM> W/mK. The upper limit value of the thermal conductivity is not particularly limited, but may be <NUM>,<NUM> W/mK. The thermal conductivity can be measured by 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. Since these materials have a high refractive index and a high thermal conductivity, the translucency and thermal conductivity of skin cooling unit <NUM> can be improved. Note that, 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 a resin such as a silicone resin from a viewpoint of heat resistance and translucency. Further, skin cooling unit <NUM> may include a resin such as a silicone resin and a highly thermally conductive filler dispersed in the resin. Since skin cooling unit <NUM> includes the highly thermally conductive filler, heat of skin cooling unit <NUM> is easily dissipated, and thus skin S can be effectively cooled. The highly thermally conductive filler may contain an inorganic substance as described above.

A proportion of the inorganic substance in skin cooling unit <NUM> is preferably more than or equal to <NUM> mass%. By setting the proportion of the inorganic substance in skin cooling unit <NUM> to more than or equal to <NUM> mass%, 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 more than or equal to <NUM> mass%, still more preferably more than or equal to <NUM> mass%, particularly preferably more than or equal to <NUM> mass%, and most preferably more than or equal to <NUM> mass%.

Skin cooling unit <NUM> is preferably cooled to be from -<NUM> to <NUM> inclusive. By cooling skin cooling unit <NUM> to be more than or equal to -<NUM>, it is possible to cool skin S so that pain in skin S caused by the cooling is unlikely to occur. On the other hand, when skin cooling unit <NUM> is cooled to be less than or equal to <NUM>, inflammation due to a rise in skin temperature during light irradiation can be suppressed. Skin cooling unit <NUM> is more preferably cooled to be more than or equal to <NUM>, still more preferably more than or equal to <NUM>, and particularly preferably more than or equal to <NUM>. Further, skin cooling unit <NUM> is more preferably cooled to be less than or equal to <NUM>, still more preferably less than or equal to <NUM>, particularly preferably less than or equal to <NUM>, and most preferably less than or equal to <NUM>.

Third 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 precisely controlled. Third temperature sensor <NUM> is provided so as to face skin cooling unit <NUM>. Specifically, third temperature sensor <NUM> is provided on substrate <NUM>. In the present exemplary embodiment, third temperature sensor <NUM> includes a contact temperature sensor. Examples of the contact temperature sensor include a thermistor, a thermocouple, and a resistance temperature detector.

Push switch <NUM> is a self-reset switch. Push switch <NUM> is provided at connection unit <NUM> of second cooling unit <NUM>. Push switch <NUM> is disposed outside first light source <NUM>, second light source <NUM>, and skin cooling unit <NUM> in front-back direction X and width direction Y, and is provided so as to surround first light source <NUM>, second light source <NUM>, and skin cooling unit <NUM>. Push switch <NUM> includes two bases <NUM> and pressing unit <NUM>.

Two bases <NUM> are fixed to connection unit <NUM> outside grip unit <NUM> of second cooling unit <NUM> such that first light source <NUM>, second light source <NUM>, and skin cooling unit <NUM> are disposed therebetween in width direction Y. Bases <NUM> have a quadrangular prism shape extending upward from connection unit <NUM>.

Pressing unit <NUM> is engaged with bases <NUM>, and moves in up-down direction Z by being pressed by skin S. Pressing unit <NUM> surrounds a periphery of first light source <NUM>, second light source <NUM>, and skin cooling unit <NUM>. Pressing unit <NUM> includes two first components <NUM> and one second component <NUM>.

First component <NUM> has a columnar shape extending upward in up-down direction Z from bases <NUM>, and is provided at a substantially central portion of bases <NUM> in front-back direction X and width direction Y, respectively. Second component <NUM> is disposed so as to be in contact with a surface of first component <NUM> opposite to bases <NUM>. Second component <NUM> has a through hole at a center in front-back direction X and width direction Y, and has a donut shape extending in up-down direction Z. First light source <NUM>, second light source <NUM>, and skin cooling unit <NUM> are disposed in the through hole of second component <NUM>. A part of a surface of second component <NUM> protrudes upward in up-down direction Z from a surface of skin cooling unit <NUM> opposite to first light source <NUM> and second light source <NUM>. Note that, in the present exemplary embodiment, first component <NUM> and second component <NUM> are different components separated from each other, but pressing unit <NUM> may be formed by one component that is continuously integrally formed. Further, the number of bases <NUM>, first component <NUM>, and second component <NUM> is not particularly limited, and can be changed as appropriate.

In a case where pressing unit <NUM> is not pressed, it protrudes toward a direction opposite to first light source <NUM> and second light source <NUM> (upward in up-down direction Z) against skin cooling unit <NUM> from a surface of skin cooling unit <NUM> in contact with skin S. A contact (not illustrated) is provided inside bases <NUM> and pressing unit <NUM>. While pressing unit <NUM> is not pressed, push switch <NUM> is configured such that a circuit to which first light source <NUM> and second light source <NUM> are connected is opened without contact between a contact of bases <NUM> and a contact of pressing unit <NUM>. On the other hand, in a case where pressing unit <NUM> is pressed, a surface pressed by skin S moves toward the direction of first light source <NUM> and second light source <NUM> (downward in up-down direction Z) against skin cooling unit <NUM>. Therefore, a contact provided in bases <NUM> and a contact provided in pressing unit <NUM> come into contact with each other, whereby the circuit to which first light source <NUM> and second light source <NUM> are connected is closed.

An elastic body (not illustrated) is provided between bases <NUM> and pressing unit <NUM>. In a case where pressing unit <NUM> is pressed, the elastic body is elastically deformed, and pushes back pressing unit <NUM> by an elastic force generated by an elastic deformation. Therefore, when the force that presses pressing unit <NUM> is removed, the elastic body acts on pressing unit <NUM> so as to return pressing unit <NUM> to its original position, and thus a contact surface of pressing unit <NUM> with skin S moves toward a direction opposite to bases <NUM> (upward in up-down direction Z).

Push switch <NUM> switches between emission and non-emission of light from first light source <NUM> and second light source <NUM>. Light is emitted from first light source <NUM> and second light source <NUM> during at least a part of time while pressing unit <NUM> is pressed. While pressing unit <NUM> is not pressed, light is not emitted from first light source <NUM> and second light source <NUM>. Therefore, it is configured such that skin S is irradiated with light during at least a part of time while light irradiation hair removal device <NUM> is pressed against skin S, and the irradiation of light is stopped when light irradiation hair removal device <NUM> is separated from skin S.

Light may be emitted immediately after push switch <NUM> is pressed, or may be emitted after a predetermined time has elapsed since push switch <NUM> was pressed. A timing at which light is emitted from first light source <NUM> and second light source <NUM> may be controlled by controller <NUM>. Light irradiation hair removal device <NUM> may emit light from first light source <NUM> and second light source <NUM> after skin S comes into contact with a surface of skin cooling unit <NUM>. As a result, the skin surface is irradiated with light in a cooled state. Therefore, since heat generation of skin S is suppressed, irritation to the skin S can be suppressed. Further, since skin S is irradiated with light in contact with skin cooling unit <NUM>, an uneven irradiation can be suppressed, and a stable hair removal effect can be obtained.

First cooling unit <NUM> cools first light source <NUM>. First cooling unit <NUM> is provided on a surface of substrate <NUM> opposite to first light source <NUM> so as to face first light source <NUM> across substrate <NUM>. Then, first cooling unit <NUM> cools first light source <NUM> via substrate <NUM>. First cooling unit <NUM> may cool first light source <NUM> so that the temperature of first light source <NUM> becomes lower than the temperature of second light source <NUM>. Note that, in the present exemplary embodiment, first cooling unit <NUM> includes a Peltier element. Then, one surface of first cooling unit <NUM> is connected to substrate <NUM>, and heat dissipation fin <NUM> of second cooling unit <NUM> is connected to the other surface. However, first cooling unit <NUM> is not particularly limited as long as it can cool first light source <NUM>.

Second cooling unit <NUM> cools second light source <NUM>. Second cooling unit <NUM> is provided on a surface of substrate <NUM> opposite to second light source <NUM> so as to face second light source <NUM> across substrate <NUM>. Specifically, second cooling unit <NUM> is connected to an edge of substrate <NUM>. Then, second cooling unit <NUM> cools second light source <NUM> via substrate <NUM>. In the present exemplary embodiment, second cooling unit <NUM> includes an air-cooled cooler.

Further, second cooling unit <NUM> cools skin cooling unit <NUM>. Since light irradiation hair removal device <NUM> includes second cooling unit <NUM>, the temperature of skin cooling unit <NUM> can be further lowered. Therefore, a skin cooling effect by skin cooling unit <NUM> can be further improved. Second cooling unit <NUM> includes heat dissipation unit <NUM> and air blower <NUM>.

Heat dissipation unit <NUM> is connected to skin cooling unit <NUM>, and dissipates heat taken from skin cooling unit <NUM>. Heat dissipation unit <NUM> includes connection unit <NUM>, grip unit <NUM>, and heat dissipation fin <NUM>.

Connection unit <NUM> is a plate-shaped member having an opening at the central portion. Substrate <NUM> is provided on a first surface, which is one surface of connection unit <NUM>. Substrate <NUM> is smaller than connection unit <NUM>, and is provided so as to be accommodated inside connection unit <NUM>. Grip unit <NUM> and push switch <NUM> are connected to outside of substrate <NUM> on the first surface of connection unit <NUM>. Heat dissipation fin <NUM> is provided on a second surface, which is a surface opposite to the first surface of connection unit <NUM>. First cooling unit <NUM>, first temperature sensor <NUM>, and second temperature sensor <NUM> are disposed in the opening of connection unit <NUM>.

Grip unit <NUM> protrudes upward in up-down direction Z from the first surface of connection unit <NUM>, and grips the entire peripheral edge of skin cooling unit <NUM>. Therefore, first light source <NUM> and second light source <NUM> are surrounded by skin cooling unit <NUM>, grip unit <NUM>, and connection unit <NUM>. The heat generated by first light source <NUM> and second light source <NUM> is dissipated via skin cooling unit <NUM> and heat dissipation unit <NUM> of second cooling unit <NUM>. Note that, while grip unit <NUM> grips the entire peripheral edge of skin cooling unit <NUM>, grip unit <NUM> may be connected to at least a part of skin cooling unit <NUM>.

Heat dissipation fin <NUM> is provided on the second surface of connection unit <NUM>, which is a surface opposite to first light source <NUM> and second light source <NUM>. Therefore, the heat of skin cooling unit <NUM> and first cooling unit <NUM> moves to heat dissipation fin <NUM> through grip unit <NUM> and connection unit <NUM>. Heat dissipation fin <NUM> includes a plurality of fins, and has a large contact area with air, so that heat is easily dissipated.

Heat dissipation unit <NUM> preferably contains a material excellent in thermal conductivity. The value of the thermal conductivity of heat dissipation unit <NUM> may be larger than the value of the thermal conductivity of skin cooling unit <NUM>. Specifically, heat dissipation unit <NUM> may contain a metal such as aluminum, iron, or copper. Grip unit <NUM>, connection unit <NUM>, and heat dissipation fin <NUM> may be made of the same material, or may be made of different materials.

Air blower <NUM> cools heat dissipation unit <NUM> by sending air to heat dissipation unit <NUM>. Air blower <NUM> includes, for example, a fan, and when the fan rotates, an air flow is generated. Housing <NUM> is provided with a plurality of first opening portions <NUM> at positions facing air blower <NUM>. Further, housing <NUM> is provided with a plurality of second opening portions <NUM> at positions facing heat dissipation fin <NUM>. Therefore, when air blower <NUM> is driven, air taken in from outside of housing <NUM> through the plurality of first opening portions <NUM> is sent to heat dissipation fin <NUM>. The heat of the air in contact with heat dissipation fin <NUM> is exchanged with the heat of heat dissipation fin <NUM>, and heat dissipation fin <NUM> is cooled. The air heated in contact with heat dissipation fin <NUM> is discharged to outside of housing <NUM> through the plurality of second opening portions <NUM>.

<FIG> is a control block diagram according to controller <NUM>. Controller <NUM> is provided on substrate <NUM> (see <FIG>). Controller <NUM> controls emission and non-emission of light from first light source <NUM> and second light source <NUM>. Further, controller <NUM> controls a drive and stop of first cooling unit <NUM> and second cooling unit <NUM>. As shown in <FIG>, first temperature sensor <NUM>, second temperature sensor <NUM>, third temperature sensor <NUM>, push switch <NUM>, and mode selection unit <NUM> are connected to an input side of controller <NUM>. On the other hand, first light source <NUM>, second light source <NUM>, first cooling unit <NUM>, and second cooling unit <NUM> are connected to an output side of controller <NUM>. Controller <NUM> has a computer system including a central processing unit (CPU), a read only memory (ROM), and a random access memory (RAM). Then, when the CPU executes programs stored in the ROM, the computer system functions as controller <NUM>. Here, the programs executed by the CPU are recorded in advance in the ROM of the computer system, but may be provided by being recorded in a non-transitory recording medium such as a memory card, or may be provided through a telecommunication line such as the Internet.

Controller <NUM> turns on or blinks first light source <NUM> and second light source <NUM> in a case where push switch <NUM> is pressed. Controller <NUM> may cause first light source <NUM> and second light source <NUM> to emit light simultaneously when push switch <NUM> is pressed, or may cause first light source <NUM> and second light source <NUM> to emit light after a predetermined time has elapsed since push switch <NUM> was pressed.

Controller <NUM> may cause second cooling unit <NUM> to cool skin cooling unit <NUM> so that the temperature of skin cooling unit <NUM> is from -<NUM> to <NUM> inclusive. Controller <NUM> may receive signals related to the temperature of skin cooling unit <NUM> from third temperature sensor <NUM>, and drive second cooling unit <NUM> so as to cool skin cooling unit <NUM> based on the signals. Controller <NUM> may cool skin cooling unit <NUM> by controlling an output of air blower <NUM> or the like.

Controller <NUM> may control the cooling by first cooling unit <NUM> so as to cool first light source <NUM> to a temperature different from that of second light source <NUM> based on the temperature of first light source <NUM> detected by first temperature sensor <NUM> and the temperature of second light source <NUM> detected by second temperature sensor <NUM>. Then, controller <NUM> may shift the wavelength of light emitted from first light source <NUM> to a wavelength different from the wavelength of light emitted from second light source <NUM> by controlling the cooling by first cooling unit <NUM>.

Specifically, controller <NUM> acquires signals related to the temperature of first light source <NUM> detected by first temperature sensor <NUM>. Further, controller <NUM> acquires signals related to the temperature of second light source <NUM> detected by second temperature sensor <NUM>. In a case where the temperature of first light source <NUM> is different from the temperature of second light source <NUM>, controller <NUM> does not cause first cooling unit <NUM> to cool first light source <NUM>, but acquires again the signals related to the temperatures of first light source <NUM> and second light source <NUM> from first temperature sensor <NUM> and second temperature sensor <NUM> and compares them. On the other hand, in a case where the temperature of first light source <NUM> and the temperature of second light source <NUM> are the same, controller <NUM> causes first cooling unit <NUM> to cool first light source <NUM>.

Controller <NUM> may cause first cooling unit <NUM> to cool first light source <NUM> so that the temperature of first light source <NUM> becomes lower than the temperature of second light source <NUM>. For example, controller <NUM> compares the temperature of first light source <NUM> with the temperature of second light source <NUM>, and causes first cooling unit <NUM> to cool first light source <NUM> in a case where the temperature of first light source <NUM> is more than or equal to the temperature of second light source <NUM>. Further, in a case where the temperature of first light source <NUM> is less than or equal to a threshold value, controller <NUM> stops cooling first light source <NUM>.

Controller <NUM> may cause first cooling unit <NUM> to control the temperature of first light source <NUM> so as to be in a predetermined temperature range according to parts of skin S irradiated with light from first light source <NUM> and light from second light source <NUM>. Hair follicles vary in size depending on each part. For example, hair follicles of beards are large and hair follicles of downy hair are small. Therefore, by controlling the temperature of first light source <NUM> according to each part, each part can be irradiated with light having an optimum wavelength. Controller <NUM> may read upper limit and lower limit threshold temperature values stored in a storage (not illustrated), and cause first cooling unit <NUM> to cool first light source <NUM>. Then, controller <NUM> may cause first cooling unit <NUM> to cool first light source <NUM> so as to be within a range from the upper limit threshold temperature value to the lower limit threshold temperature value corresponding to each predetermined part. The part to be irradiated with light may be set by a user via mode selection unit <NUM>, or may be determined by controller <NUM> according to an outer appearance of hair.

Mode selection unit <NUM> is connected to substrate <NUM>, and at least a part thereof is exposed on the outer surface. Mode selection unit <NUM> is provided with a switch (not illustrated) capable of selecting a part of skin S on the exposed outer surface. Mode selection unit <NUM> may include, for example, one switch capable of switching each part every time it is pressed. Further, mode selection unit <NUM> may include a plurality of switches corresponding to the respective parts, and the respective parts selected by pressing the respective switches may be selected. The switch may be a push button switch or a touch panel switch.

The following describes operations and actions of light irradiation hair removal device <NUM> configured as described above.

With reference to <FIG>, a state in which light is emitted by light irradiation hair removal device <NUM> will be described. <FIG> is a cross-sectional view illustrating one example of a state before use of light irradiation hair removal device <NUM>. <FIG> is a cross-sectional view illustrating one example of a state of light irradiation hair removal device <NUM> before push switch <NUM> is pressed. <FIG> is a cross-sectional view illustrating one example of a state of light irradiation hair removal device <NUM> after push switch <NUM> is pressed. <FIG> is a cross-sectional view illustrating an example of a state of light irradiation hair removal device <NUM> while skin S is irradiated with light.

As shown in <FIG>, push switch <NUM> is not pressed before use of light irradiation hair removal device <NUM>. Therefore, pressing unit <NUM> of push switch <NUM> protrudes toward a direction opposite to first light source <NUM> and second light source <NUM> against skin cooling unit <NUM> from a surface of skin cooling unit <NUM> in contact with skin S. In this state, light is not emitted from first light source <NUM> and second light source <NUM>.

As shown in <FIG>, when light irradiation hair removal device <NUM> is used, skin S of a user is pressed against light irradiation hair removal device <NUM>. Pressing unit <NUM> of push switch <NUM> protrudes from a skin contact surface of skin cooling unit <NUM>. Therefore, skin S of the user first comes into contact with push switch <NUM>, and first light source <NUM> and second light source <NUM> are surrounded by skin S and push switch <NUM>.

As shown in <FIG>, push switch <NUM> is pressed in contact with skin S. Specifically, in a case where pressing unit <NUM> of push switch <NUM> is pressed, the surface pressed by skin S moves toward the direction of first light source <NUM> and second light source <NUM> against skin cooling unit <NUM>. As a result, skin S comes into contact with skin cooling unit <NUM> in a state where first light source <NUM> and second light source <NUM> are surrounded by skin S and push switch <NUM>, and skin cooling unit <NUM> is shielded by skin S. Then, skin S is cooled by coming into contact with skin cooling unit <NUM>.

As shown in <FIG>, a circuit to which first light source <NUM> and second light source <NUM> are connected is closed by push switch <NUM>, and light is emitted from first light source <NUM> and second light source <NUM>. Since skin cooling unit <NUM> is shielded by skin S, and first light source <NUM> and second light source <NUM> are also surrounded by push switch <NUM>, skin S is irradiated with light emitted from first light source <NUM> and second light source <NUM> without leakage. In order to bring skin cooling unit <NUM> and skin S into contact with each other more reliably, light may be emitted from first light source <NUM> and second light source <NUM> after a predetermined time has elapsed since pressing unit <NUM> of push switch <NUM> was pressed.

Further, in the present exemplary embodiment, light irradiation hair removal device <NUM> includes first cooling unit <NUM> and second cooling unit <NUM>. In the present exemplary embodiment, first light source <NUM> and second light source <NUM> include a plurality of LEDs, and the peak wavelength of the LEDs shifts depending on the temperature. For example, when the temperature of the LEDs decreases by about several tens of degrees Celsius, the wavelength of the emitted light decreases by about several tens of nanometers. Therefore, by cooling first light source <NUM>, first cooling unit <NUM> shifts the wavelength of light emitted from first light source <NUM> to a wavelength different from the wavelength of light emitted from second light source <NUM>.

By shifting the wavelength of light, a light depth entering skin S changes due to wavelength dependency of light scattering. For example, when the temperature of first light source <NUM> is lowered and the wavelength of light is shortened, the light depth becomes shallow. On the other hand, since the wavelength of the light of second light source <NUM> is longer than that of first light source <NUM>, light is less scattered in skin S, and the light depth reaching skin S is deep. Then, the entire melanocytes including melanin of hair follicles are heated when skin S is irradiated with light having different depths. In this way, the wavelengths of light emitted from first light source <NUM> and second light source <NUM> can be easily adjusted respectively by independently controlling the temperatures of first light source <NUM> and second light source <NUM>. Therefore, for light irradiation hair removal device <NUM> according to the present exemplary embodiment, it is also possible to effectively remove a hair follicle size part where a sufficient hair removal effect cannot be obtained by a device in which only LEDs of different emission wavelengths are arranged.

As described above, light irradiation hair removal device <NUM> according to the present exemplary embodiment includes first light source <NUM>, second light source <NUM>, skin cooling unit <NUM>, push switch <NUM>, first cooling unit <NUM>, and second cooling unit <NUM>. First light source <NUM> emits light having a wavelength from <NUM> to <NUM> inclusive. Second light source <NUM> emits light having a wavelength from <NUM> to <NUM> inclusive. Skin cooling unit <NUM> faces first light source <NUM> and second light source <NUM>, transmits light emitted from first light source <NUM> and second light source <NUM>, and cools skin S in a case where it comes into contact with skin S. Push switch <NUM> includes pressing unit <NUM> surrounding a periphery of first light source <NUM>, second light source <NUM>, and skin cooling unit <NUM>. In a case where pressing unit <NUM> is not pressed, it protrudes toward a direction opposite to first light source <NUM> and second light source <NUM> against skin cooling unit <NUM> from a surface of skin cooling unit <NUM> in contact with skin S. In a case where pressing unit <NUM> is pressed, the surface pressed by skin S moves toward the direction of first light source <NUM> and second light source <NUM> against skin cooling unit <NUM>. Push switch <NUM> switches between emission and non-emission of light from first light source <NUM> and second light source <NUM>. Light is emitted from first light source <NUM> and second light source <NUM> during at least a part of time while pressing unit <NUM> is pressed, and light is not emitted from first light source <NUM> and second light source <NUM> while pressing unit <NUM> is not pressed. First cooling unit <NUM> cools first light source <NUM>. Second cooling unit <NUM> cools second light source <NUM>. By cooling first light source <NUM>, first cooling unit <NUM> shifts the wavelength of light emitted from first light source <NUM> to a wavelength different from the wavelength of light emitted from second light source <NUM>.

As a result, since first cooling unit <NUM> cools first light source <NUM> and second cooling unit <NUM> cools second light source <NUM>, light irradiation hair removal device <NUM> can set the temperature of first light source <NUM> and the temperature of second light source <NUM> to arbitrary different temperatures. Therefore, since skin S is irradiated with light of different depths due to wavelength dependency of light scattering, light irradiation hair removal device <NUM> can uniformly irradiate the entire area of melanocytes distributed in hair follicles with light.

Further, light irradiation hair removal device <NUM> can irradiate skin S with light in a state where first light source <NUM> and second light source <NUM> are surrounded by push switch <NUM> and skin S. Therefore, leakage of light can be suppressed. Further, skin cooling unit <NUM> can come into contact with skin S to cool skin S at the time of light irradiation. Therefore, inflammation of skin S can be suppressed.

Note that, light irradiation hair removal device <NUM> may include a near-infrared LED (first light source <NUM>), a push-in irradiation switch (push switch <NUM>), and a skin cooling unit (skin cooling unit <NUM>). The skin cooling unit (skin cooling unit <NUM>) is a transparent material that is cooled on a light beam that is an upper portion of the near-infrared LED (first light source <NUM>) and transmits light of the near-infrared LED (first light source <NUM>). Light irradiation hair removal device <NUM> has a configuration in which the near-infrared LED (first light source <NUM>) emits light after the skin (skin S) comes into contact with a top surface of the skin cooling unit (skin cooling unit <NUM>) by being pushed into the skin (skin S). Light irradiation hair removal device <NUM> is characterized in that the wavelength of the near-infrared LED (first light source <NUM>) is changed by arbitrarily controlling the temperature of a part of substrate <NUM> on which LED elements of the near-infrared LED (first light source <NUM>) are disposed. Even with such light irradiation hair removal device <NUM>, it is possible to uniformly irradiate the entire area of melanocytes distributed in hair follicles with light.

As in the present exemplary embodiment, light irradiation hair removal device <NUM> may further include first temperature sensor <NUM> and second temperature sensor <NUM>, which are examples of a temperature sensor according to the present disclosure, and controller <NUM>. First temperature sensor <NUM> and second temperature sensor <NUM> may detect the temperature of first light source <NUM> and the temperature of second light source <NUM>. Controller <NUM> may control the cooling by first cooling unit <NUM> so as to cool first light source <NUM> to a temperature different from the temperature of second light source <NUM> according to the temperatures of first light source <NUM> and second light source <NUM> detected by first temperature sensor <NUM> and second temperature sensor <NUM>.

As a result, light irradiation hair removal device <NUM> can more precisely control the temperature of first light source <NUM>. Therefore, light irradiation hair removal device <NUM> can further precisely control the light depth entering skin S.

As in light irradiation hair removal device <NUM> according to the present exemplary embodiment, first cooling unit <NUM> may include a Peltier element, and first temperature sensor <NUM> and second temperature sensor <NUM> may include a thermistor.

As a result, light irradiation hair removal device <NUM> can cool first light source <NUM> more powerfully and control the temperature of first light source <NUM> with higher accuracy. Therefore, light irradiation hair removal device <NUM> can further precisely control the light depth entering skin S.

As in light irradiation hair removal device <NUM> according to the present exemplary embodiment, first cooling unit <NUM> may cool first light source <NUM> so that the temperature of first light source <NUM> becomes lower than the temperature of second light source <NUM>.

As a result, the wavelength of the light of first light source <NUM> becomes shorter than the wavelength of the light of second light source <NUM>. Upper portions of hair follicles have more melanocytes than lower portions of hair follicles. Light irradiation hair removal device <NUM> irradiates the upper portions of hair follicles with light by first light source <NUM> and irradiates the deep portions of hair follicles with light by second light source <NUM>, so that a light amount according to the melanocyte distribution can be irradiated, and thus the hair removal effect can be further improved.

As in light irradiation hair removal device <NUM> according to the present exemplary embodiment, first cooling unit <NUM> may cool first light source <NUM> so as to be in a predetermined temperature range according to parts of skin S irradiated with light from first light source <NUM> and second light source <NUM>.

As a result, light irradiation hair removal device <NUM> can emit light of an optimum wavelength from first light source <NUM> and second light source <NUM> according to the parts. Therefore, light irradiation hair removal device <NUM> can obtain a higher hair removal effect.

As described above, the above exemplary embodiment has been described as an example of the technology in the present disclosure. However, the technology of the present disclosure is not limited to them, and is also applicable to exemplary embodiments in which changes, replacements, additions, omissions, and the like are made. Thus, hereinafter, other exemplary embodiments are illustrated as examples.

Light irradiation hair removal device <NUM> according to the above exemplary embodiment has been described as an example that first light source <NUM> and second light source <NUM> include LEDs. However, it is sufficient that first light source <NUM> and second light source <NUM> can emit light having a wavelength from <NUM> to <NUM> inclusive. First light source <NUM> and second light source <NUM> are not limited to LEDs, and may be, for example, laser diodes.

Further, skin cooling unit <NUM> may include an antireflection film for preventing light emitted from first light source <NUM> and second light source <NUM> from being reflected. The antireflection film may be provided, for example, on a surface of skin cooling unit <NUM> facing first light source <NUM> and second light source <NUM>. By providing such an antireflection film in skin cooling unit <NUM>, reflection of light is suppressed, and skin S can be irradiated with a large amount of light.

Further, light irradiation hair removal device <NUM> according to the above exemplary embodiment has been described as an example that it cools skin cooling unit <NUM> using second cooling unit <NUM>. However, in a case where the thermal conductivity of skin cooling unit <NUM> is high, it is not always necessary to cool skin cooling unit <NUM> using second cooling unit <NUM>, since the heat dissipation of skin cooling unit <NUM> is high.

Further, light irradiation hair removal device <NUM> according to the above exemplary embodiment has been described as an example that second cooling unit <NUM> is connected to skin cooling unit <NUM> to cool skin cooling unit <NUM>. However, second cooling unit <NUM> does not need to be connected to skin cooling unit <NUM>.

Further, as an example, light irradiation hair removal device <NUM> according to the above exemplary embodiment uses first temperature sensor <NUM> to measure the temperature of first light source <NUM>. Further, as an example, light irradiation hair removal device <NUM> according to the above exemplary embodiment uses second temperature sensor <NUM> to measure the temperature of second light source <NUM>. However, by calculating the thermal conductivity of substrate <NUM> or the like, it is possible to estimate the temperatures of first light source <NUM> and second light source <NUM> with one temperature sensor. Therefore, light irradiation hair removal device <NUM> does not need to use two temperature sensors, and may include one temperature sensor that measures the temperatures of first light source <NUM> and second light source <NUM>.

Note that, since 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 claims.

Claim 1:
A light irradiation hair removal device comprising:
a first light source (<NUM>) configured to emit first light having a wavelength from <NUM> to <NUM> inclusive;
a second light source (<NUM>) configured to emit second light having a wavelength from <NUM> to <NUM> inclusive;
a skin cooling unit (<NUM>) that faces the first light source and the second light source, configured to transmit the first light emitted from the first light source and the second light emitted from the second light source, and to cool
a skin when the skin cooling unit comes into contact with the skin;
a push switch (<NUM>) that includes a pressing unit (<NUM>) surrounding a periphery of the first light source, the second light source, and the skin cooling unit;
wherein
when the pressing unit is not being pressed, the pressing unit protrudes toward a direction opposite to the first light source and the second light source against the skin cooling unit from a surface of the skin cooling unit in contact with the skin;
when the pressing unit is pressed by the skin, a surface of which pressed by the skin moves toward the direction of the first light source and the second light source against the skin cooling unit; and
the push switch is configured to switch between emission and non-emission of the first
light from the first light source and the second light from the second light source such that the first light is emitted from the first light source and the second light is emitted from the second light source during at least a part of time while the pressing unit is pressed, and the first light is not emitted from the first light source and the second light is not emitted from the second light source while the pressing unit is not pressed;
a first cooling unit (<NUM>) configured to cool the first light source; and
a second cooling unit (<NUM>) configured to cool the second light source, wherein
the first cooling unit is configured to shift
the wavelength of the first light emitted from the first light source to a wavelength different from the wavelength of the second light emitted from the second light source by cooling the first light source.