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. The processing light has a wavelength in a range from <NUM> to <NUM>, an energy density in a range from <NUM> J/cm<NUM> to <NUM> J/cm<NUM>, and a pulse duration within <NUM> to <NUM>.

A further relevant prior art is formed by document <CIT>.

In a conventional light irradiation hair removal device, an application of light is controlled depending on characteristics of the target object to be irradiated with light. However, a sensitivity to pain of the user varies, and the user tends to feel pain as the skin is irradiated with stronger light to obtain a sufficient hair removal effect. Therefore, even when the application of light is controlled depending on the characteristics of the target object, the user may feel uncomfortable in a case where the skin is irradiated with stronger light.

The present disclosure provides a light irradiation hair removal device capable of reducing discomfort associated with light irradiation.

A light irradiation hair removal device according to one aspect of the present disclosure includes a light source, a skin cooling unit, and a push switch. The light source intermittently emits light including a first irradiation light and a second irradiation light emitted for a longer time than the first irradiation light before the first irradiation light, and having a wavelength from <NUM> to <NUM> inclusive. The skin cooling unit faces the light source, transmits light emitted from the light source, and cools a skin in a case where it comes into contact with the skin. The push switch includes a pressing unit surrounding a periphery of the light source and the skin cooling unit. In a case where the pressing unit is not pressed, it protrudes toward a direction opposite to the 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, a surface pressed by the skin moves toward the direction of the light source against the skin cooling unit. The push switch switches between emission and non-emission of light from the light source such that light is emitted from the light source during at least a part of time while the pressing unit is pressed, and light is not emitted from the light source while the pressing unit is not pressed. The first irradiation light has a maximum irradiance that is the largest irradiance of light emitted by the light source in an intermittent manner, and the second irradiation light has an irradiance smaller than the maximum irradiance.

According to the present disclosure, it is possible to obtain a light irradiation hair removal device capable of reducing discomfort associated with light irradiation.

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>, light source <NUM>, temperature sensor <NUM>, skin cooling unit <NUM>, push switch <NUM>, cooler <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>. Light source <NUM> is provided in the opening portion of housing <NUM>, and emits light on skin S of a person. Further, a bottom portion is formed on a side of housing <NUM> opposite to 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>, light source <NUM>, temperature sensor <NUM>, skin cooling unit <NUM>, push switch <NUM>, cooler <NUM>, and controller <NUM> are accommodated.

<FIG> is a perspective view illustrating an example of a schematic arrangement state of light source <NUM> according to the present exemplary embodiment. Note that, in <FIG>, configurations of temperature sensor <NUM>, skin cooling unit <NUM>, push switch <NUM>, and cooler <NUM> are partially omitted. As shown in <FIG>, in the present exemplary embodiment, light source <NUM> includes a plurality of light emitting diodes (LEDs). The LEDs are mounted on substrate <NUM> in a state of being spaced at substantially equal intervals. Light source <NUM> is electrically connected to a power supply (not illustrated), and when power is supplied from the power supply, light is emitted from light source <NUM>.

Light source <NUM> intermittently emits light including first irradiation light L1 and second irradiation light L2 emitted before first irradiation light L1. First irradiation light L1 has a maximum irradiance that is the largest irradiance of light emitted by light source <NUM> in an intermittent manner. Second irradiation light L2 has an irradiance smaller than the maximum irradiance. Second irradiation light L2 is emitted for a longer time than first irradiation light L1.

<FIG> is a graph illustrating an example of a relationship between the irradiation time and irradiance of light emitted from light source <NUM>. As shown in <FIG>, first, second irradiation light L2 is emitted from light source <NUM>. The irradiance of second irradiation light L2 is <NUM> W/cm<NUM>, and the irradiation time of second irradiation light L2 is <NUM>. Next, first irradiation light L1 is emitted from light source <NUM> following the emission of second irradiation light L2. The irradiance of first irradiation light L1 is <NUM> W/cm<NUM>, and the irradiation time of first irradiation light L1 is <NUM>. Therefore, total irradiation time of second irradiation light L2 and first irradiation light L1 is <NUM>. After second irradiation light L2 and first irradiation light L1 are emitted, light emission by light source <NUM> is stopped. Off time of light source <NUM> is <NUM>. Next, second irradiation light L2 and first irradiation light L1 are emitted again from light source <NUM> in this order. Light source <NUM> intermittently emits light including second irradiation light L2 and first irradiation light L1 by repeatedly turning on and off light including second irradiation light L2 and first irradiation light L1.

First irradiation light L1 may have a constant irradiance in a predetermined time period as shown in <FIG>, but the irradiance may increase or decrease with a lapse of time. The irradiance of first irradiation light L1 may be within a range from more than <NUM>% to less than or equal to <NUM>% relative to the maximum irradiance.

The irradiance of light emitted from light source <NUM> is preferably more than <NUM> W/cm<NUM> and less than or equal to <NUM> W/cm<NUM>. By setting the irradiance within the above range, it is possible to suppress a rise in skin temperature due to light irradiation, and to reduce skin irritation. The irradiance may be less than or equal to <NUM> W/cm<NUM>, or less than or equal to <NUM> W/cm<NUM>. Further, the irradiance of light emitted from light source <NUM> is preferably more than or equal to <NUM> W/cm<NUM>. 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. 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>.

The irradiance of first irradiation light L1 is preferably more than <NUM> W/cm<NUM> and less than or equal to <NUM> W/cm<NUM>. By setting the irradiance within the above range, it is possible to suppress a rise in skin temperature due to light irradiation, and to reduce skin irritation. Further, the irradiance of first irradiation light L1 is preferably more than or equal to <NUM> W/cm<NUM>. 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. The irradiance may be more than or equal to <NUM> W/cm<NUM>, or more than or equal to <NUM> W/cm<NUM>.

Second irradiation light L2 has an irradiance smaller than the maximum irradiance. As a result, since a user gets used to the pain due to the irradiation of second irradiation light L2, it is difficult for the user to feel pain even when irradiated with first irradiation light L1, and the user's discomfort can be reduced. The irradiance of second irradiation light L2 may be more than or equal to <NUM> W/cm<NUM>. Further, the irradiance of second irradiation light L2 may be less than or equal to <NUM> W/cm<NUM>, or less than or equal to <NUM> W/cm<NUM>.

The irradiance of second irradiation light L2 may be less than or equal to <NUM>% relative to the maximum irradiance. As a result, since the user gets used to the pain by the irradiation of second irradiation light L2, it is difficult for the user to feel pain even when irradiated with first irradiation light L1, and the user's discomfort can be further reduced. The irradiance of second irradiation light L2 may be less than or equal to <NUM>%, less than or equal to <NUM>%, less than or equal to <NUM>%, or less than or equal to <NUM>% relative to the maximum irradiance. Further, the irradiance of second irradiation light L2 may be more than or equal to <NUM>%, more than or equal to <NUM>%, or more than or equal to <NUM>% relative to the maximum irradiance.

Respective irradiation time of light emitted from light source <NUM> in an intermittent manner, which is the total irradiation time of light in one cycle, is preferably 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 and to reduce skin irritation. 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>.

Second irradiation light L2 is emitted for a longer time than first irradiation light L1. As a result, hair removal can be promoted by increasing the temperature of hair follicles while reducing the irritation to skin S due to light irradiation. The irradiation time of first irradiation light L1 is preferably more than <NUM> and less than <NUM>. The irradiation time of first irradiation light L1 may be more than or equal to <NUM>, or more than or equal to <NUM>. Further, the irradiation time of first irradiation light L1 may be less than or equal to <NUM>. The irradiation time of second irradiation light L2 is preferably more than <NUM> and less than or equal to <NUM>. The irradiation time of second irradiation light L2 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>.

A ratio of the irradiation time of first irradiation light L1 to the irradiation time of each light emitted from light source <NUM> in an intermittent manner (which is the total irradiation time of each light) is preferably from <NUM> to <NUM> inclusive. By setting the ratio within the above range, it is possible to further reduce irritation to skin S due to light irradiation. The ratio may be more than or equal to <NUM>, or more than or equal to <NUM>. Further, the ratio may be less than or equal to <NUM>, or less than or equal to <NUM>.

A ratio of the irradiation time of second irradiation light L2 to the irradiation time of each light emitted from light source <NUM> in an intermittent manner (which is the total irradiation time of each light) is preferably from <NUM> to <NUM> inclusive. By setting the ratio within the above range, it is possible to further promote hair removal by increasing the temperature of hair follicles while further reducing irritation to skin S due to light irradiation. The ratio may be more than or equal to <NUM>. Further, the ratio may be less than or equal to <NUM>.

A ratio of the total irradiation time of first irradiation light L1 and second irradiation light L2 to the irradiation time of each light emitted from light source <NUM> in an intermittent manner (which is the total irradiation time of each 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>.

A ratio of the irradiation time of first irradiation light L1 to the irradiation time of second irradiation light L2 is preferably more than <NUM> and less than or equal to <NUM>. By setting the ratio within the above range, it is possible to further reduce irritation to skin S due to light irradiation. The ratio may be more than or equal to <NUM>. Further, the ratio may be less than or equal to <NUM>, or less than or equal to <NUM>.

Light source <NUM> emits 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 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. Further, each of the LEDs does not need to have the same wavelength spectrum, and LEDs that emit light of different wavelength spectra may be used in combination. Note that, the wavelength is a wavelength of light emitted in a case where the temperature of light source <NUM> is <NUM>.

Energy of each pulsed light emitted from 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.

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 with a space from light source <NUM>. Further, skin cooling unit <NUM> is provided so as to be in contact with skin S on a side opposite to light source <NUM>. Skin cooling unit <NUM> is made of a material having translucency. When light source <NUM> emits light, skin cooling unit <NUM> transmits light emitted from 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 difficult to absorb light emitted from 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 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 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 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>.

Temperature sensor <NUM> detects a temperature of skin S of the user. Temperature sensor <NUM> is provided so as to face skin cooling unit <NUM>. Specifically, temperature sensor <NUM> is provided on substrate <NUM>. In the present exemplary embodiment, temperature sensor <NUM> includes a non-contact temperature sensor such as a radiation thermometer.

Push switch <NUM> is a self-reset switch. Push switch <NUM> is provided at connection unit <NUM> of cooler <NUM>. Push switch <NUM> is disposed outside light source <NUM> and skin cooling unit <NUM> in front-back direction X and width direction Y, and is provided so as to surround 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 cooler <NUM> such that 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 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. Light source <NUM> and skin cooling unit <NUM> are disposed in the through-hole of second component <NUM>. A part of the surface of second component <NUM> protrudes upward in up-down direction Z from a surface of skin cooling unit <NUM> opposite to 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 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. Contact points (not illustrated) are provided inside bases <NUM> and pressing unit <NUM>, and push switch <NUM> is configured such that while pressing unit <NUM> is not pressed, a circuit to which light source <NUM> is connected is opened without contact point between the contact point of bases <NUM> and the contact point 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 light source <NUM> (downward in up-down direction Z) against skin cooling unit <NUM>. Therefore, the contact point provided in bases <NUM> and the contact point provided in pressing unit <NUM> come into contact with each other, whereby the circuit to which light source <NUM> is 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 light source <NUM> such that light is emitted from light source <NUM> during at least a part of time while pressing unit <NUM> is pressed, and light is not emitted from light source <NUM> while pressing unit <NUM> is not pressed. 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 light source <NUM> may be controlled by controller <NUM>. Light irradiation hair removal device <NUM> may emit light from 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.

Cooler <NUM> cools skin cooling unit <NUM>. Since light irradiation hair removal device <NUM> includes cooler <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. Cooler <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. 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>.

Grip unit <NUM> protrudes upward in up-down direction Z from the first surface of connection unit <NUM>, and grips an entire peripheral edge of skin cooling unit <NUM>. Therefore, light source <NUM> is surrounded by skin cooling unit <NUM>, grip unit <NUM>, and connection unit <NUM>. The heat generated by light source <NUM> is dissipated via skin cooling unit <NUM> and heat dissipation unit <NUM> of cooler <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 light source <NUM>. Therefore, the heat of skin 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>.

Note that, in the present exemplary embodiment, it has been described that light irradiation hair removal device <NUM> cools skin cooling unit <NUM> using air-cooled cooler <NUM>, but skin cooling unit <NUM> may be cooled using a Peltier element or the like in addition to air-cooled cooler <NUM> or instead of air-cooled cooler <NUM>. Light irradiation hair removal device <NUM> in a case of cooling skin cooling unit <NUM> using the Peltier element can cool skin cooling unit <NUM> more strongly.

<FIG> is a control block diagram according to controller <NUM>. Controller <NUM> controls emission and non-emission of light from light source <NUM>. Further, controller <NUM> controls a drive and stop of air blower <NUM>. As shown in <FIG>, temperature sensor <NUM> and push switch <NUM> are connected to an input side of controller <NUM>. On the other hand, light source <NUM> and cooler <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 light source <NUM> in a case where push switch <NUM> is pressed. Controller <NUM> may cause light source <NUM> to emit light simultaneously when push switch <NUM> is pressed, or may cause light source <NUM> to emit light after a predetermined time period has elapsed since push switch <NUM> was pressed.

Controller <NUM> may receive signals related to the temperature of skin S from temperature sensor <NUM>, and control the irradiation time of first irradiation light L1 by light source <NUM> according to the signals. As a result, since the irradiation of first irradiation light L1 can be stopped before the temperature of skin S becomes excessive, skin irritation can be reduced. Preferably, controller <NUM> controls the irradiation time of first irradiation light L1 such that the temperature of skin S is from -<NUM> to <NUM> inclusive. By controlling the temperature of skin S to be more than or equal to -<NUM>, the pain in skin S associated with cooling can be less likely to occur. On the other hand, by controlling the temperature of skin S to be less than or equal to <NUM>, it is possible to reduce skin irritation associated with light irradiation.

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 one 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 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 light source <NUM>.

As shown in <FIG>, when light irradiation hair removal device <NUM> is used, skin S of the 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 light source <NUM> is surrounded by skin S and push switch <NUM>.

As shown in <FIG>, push switch <NUM> is pressed in a state of being 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 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 light source <NUM> is 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 light source <NUM> is connected is closed by push switch <NUM>, and light is emitted from light source <NUM>. Since skin cooling unit <NUM> is shielded by skin S, and light source <NUM> is also surrounded by push switch <NUM>, skin S is irradiated with light emitted from 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 light source <NUM> after a predetermined time period has elapsed since pressing unit <NUM> of push switch <NUM> was pressed.

As described above, light irradiation hair removal device <NUM> according to the present exemplary embodiment includes light source <NUM>, skin cooling unit <NUM>, and push switch <NUM>. Light source <NUM> intermittently emits light including first irradiation light L1 and second irradiation light L2 emitted for a longer time than first irradiation light L1 before first irradiation light L1, and having a wavelength from <NUM> to <NUM> inclusive. Skin cooling unit <NUM> faces light source <NUM>, transmits light emitted from 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 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 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 light source <NUM> against skin cooling unit <NUM>. Push switch <NUM> switches between emission and non-emission of light from light source <NUM> such that light is emitted from light source <NUM> during at least a part of time while pressing unit <NUM> is pressed, and light is not emitted from light source <NUM> while pressing unit <NUM> is not pressed. First irradiation light L1 has a maximum irradiance that is the largest irradiance of light emitted by light source <NUM> in an intermittent manner, and second irradiation light L2 has an irradiance smaller than the maximum irradiance.

As a result, light irradiation hair removal device <NUM> gently performs preheating with less skin irritation by second irradiation light L2, and applies heat having a good hair removal promoting effect by first irradiation light L1. As a result, light irradiation hair removal device <NUM> can reduce skin irritation regardless of individual properties of the user as compared with a case where light having the same irradiance is emitted alone while maintaining the hair removal effect. Therefore, light irradiation hair removal device <NUM> can reduce discomfort associated with light irradiation.

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

Note that, light irradiation hair removal device <NUM> may include a near-infrared LED (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 made of a transparent material that is cooled on a light beam that is an upper portion of the near-infrared LED (light source <NUM>) and transmits light of the near-infrared LED (light source <NUM>). Light irradiation hair removal device <NUM> has a configuration in which the near-infrared LEDs (light source <NUM>) emit light after a top surface of the skin cooling unit (skin cooling unit <NUM>) comes into contact with the skin (skin S) by being pushed into the skin (skin S). In addition, light irradiation hair removal device <NUM> is characterized in that light source <NUM> is controlled so that light quantity of the near-infrared LED (light source <NUM>) becomes high from low. Even with such light irradiation hair removal device <NUM>, it is possible to reduce discomfort associated with light irradiation.

As in light irradiation hair removal device <NUM> according to the present exemplary embodiment, the irradiance of light emitted from light source <NUM> may be more than <NUM> W/cm<NUM> and less than or equal to <NUM> W/cm<NUM>.

As a result, light irradiation hair removal device <NUM> can suppress a rise in skin temperature due to light irradiation, and can reduce skin irritation.

As in light irradiation hair removal device <NUM> according to the present exemplary embodiment, the irradiation time of each light emitted from light source <NUM> in an intermittent manner, which is the total irradiation time of each light in one cycle, may be from <NUM> to <NUM> inclusive.

As a result, light irradiation hair removal device <NUM> can achieve a good hair removal effect on hair from an early growth period to a growth period while suppressing a rise in the skin temperature, and can reduce the skin irritation.

As in light irradiation hair removal device <NUM> according to the present exemplary embodiment, the irradiation time of first irradiation light L1 may be more than <NUM> and less than <NUM>, and the irradiation time of second irradiation light L2 may be longer than the irradiation time of first irradiation light L1 of more than <NUM> and less than or equal to <NUM>.

As a result, light irradiation hair removal device <NUM> can increase the temperature of hair follicles while reducing the irritation to skin S due to light irradiation. Therefore, light irradiation hair removal device <NUM> can promote hair removal while more reliably reducing discomfort associated with light irradiation.

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.

Note that, light irradiation hair removal device <NUM> according to the above exemplary embodiment has been described as an example that light source <NUM> includes LEDs. However, it is sufficient that light source <NUM> can emit light having a wavelength from <NUM> to <NUM> inclusive. Light source <NUM> is not limited to LEDs, and may include, for example, a xenon lamp, laser diodes, and a combination thereof. However, if LEDs are used as light source <NUM>, light irradiation hair removal device <NUM> can be miniaturized as described above.

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 cooler <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 cooler <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 cooler <NUM> is connected to skin cooling unit <NUM> to cool skin cooling unit <NUM>. However, cooler <NUM> does not need to be connected to skin cooling unit <NUM>.

Here, a modification of the irradiation illuminance of second irradiation light L2 will be described with reference to <FIG> is a graph illustrating another example of the relationship between the irradiation time and the irradiance of light emitted from light source <NUM>.

In the above exemplary embodiment, an example in which second irradiation light L2 has one irradiance of <NUM> W/cm<NUM> has been described. However, as shown in <FIG>, second irradiation light L2 may have two or more different irradiance. Specifically, to start with, second irradiation light L2 is emitted from light source <NUM>. Second irradiation light L2 includes light having an irradiance of <NUM> W/cm<NUM> and light having an irradiance of <NUM> W/cm<NUM>. After light having an irradiance of <NUM> W/cm<NUM> is emitted for <NUM>, light having an irradiance of <NUM> W/cm<NUM> is emitted for <NUM>. Next, first irradiation light L1 is emitted from light source <NUM> following the emission of second irradiation light L2. The irradiance of first irradiation light L1 is <NUM> W/cm<NUM>, and the irradiation time of first irradiation light L1 is <NUM>. Therefore, total irradiation time of second irradiation light L2 and first irradiation light L1 is <NUM>. After second irradiation light L2 and first irradiation light L1 are emitted, light emission by light source <NUM> is stopped. Off time of light source <NUM> is <NUM>. Next, second irradiation light L2 and first irradiation light L1 are emitted again from light source <NUM> in this order. Light source <NUM> intermittently emits light including second irradiation light L2 and first irradiation light L1 by repeatedly turning on and off light including second irradiation light L2 and first irradiation light L1. Even in a case where light is emitted in this manner, light irradiation hair removal device <NUM> according to this modification can reduce discomfort associated with light irradiation.

Note that, in <FIG>, an example in which the irradiance of second irradiation light L2 increases with the lapse of time has been described. However, second irradiation light L2 only needs to have an irradiance smaller than that of first irradiation light L1, and second irradiation light L2 may include a plurality of light, the irradiance of which decreases with the lapse of time. However, as shown in <FIG>, in a case where light source <NUM> emits light in an intermittent manner so that the irradiance increases with the lapse of time, the user is easily used to light irradiation, and thus light irradiation hair removal device <NUM> according to this modification can further reduce discomfort associated with light irradiation.

Further, in <FIG> and <FIG>, light of the same pattern is repeatedly emitted in an intermittent manner, but the pattern of each light emitted in an intermittent manner may not necessarily be the same, and light of different patterns may be emitted in an intermittent manner.

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 light source (<NUM>) configured to intermittently emit light including a first irradiation light and a second irradiation light, the second irradiation light being emitted for a longer time than the first irradiation light and before the first irradiation light, the first irradiation light and the second irradiation light each having a wavelength from <NUM> to <NUM> inclusive;
a skin cooling unit (<NUM>) that faces the light source (<NUM>) and is configured to transmit light emitted from the light source, and to cool
a skin in a case where it comes into contact with the skin; and
a push switch (<NUM>) that includes a pressing unit (<NUM>) surrounding a periphery of the 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 light source against the skin cooling unit from a surface of the skin cooling unit, the surface that is to be brought into contact with the skin,
when the pressing unit is pressed by the skin, a surface of which pressed by the skin moves toward a direction of the light source against the skin cooling unit, and
the push switch is configured to switch between emission and non-emission of light from the light source such that light is emitted from the light source during at least a part of time while the pressing unit is pressed, and light is not emitted from the light source while the pressing unit is not pressed,
wherein
the first irradiation light has a maximum irradiance that is a largest irradiance of the light emitted by the light source in an intermittent manner, and the second irradiation light has an irradiance smaller than the maximum irradiance.