Hair dryer

Abstract

A hairdryer comprising a fan (F) for generating an airflow and a drying chamber (HC) having a hair inlet (II) through which hair can be directed into the hair inlet (II) by the airflow. The drying chamber (HC) has a cross section with a first dimension in a first direction which is at least 5 times larger than a second dimension in a second direction perpendicular to the first direction, wherein the first and second directions are perpendicular to the direction of the airflow. The drying chamber (HC) can be folded such that the drying chamber has a U-turn in the direction of the airflow. A first area of the cross section of the drying chamber (HC) at the U-turn can be smaller than a second area of the cross section located intermediate the hair inlet (II) and the U-turn. The hair inlet (II) of the drying chamber (HC) can be shaped to follow the contour of a user's head. The hairdryer can be arranged to heat hair from multiple sides. A wall of the drying chamber (HC) can be provided with a hydrophilic or water absorbing or water surface tension reducing material. The water absorbing material can be regenerated by hot air. The drying chamber (HC) can be openable whereby the drying chamber can be cleaned. The hairdryer can have a sensor (MS) for sensing the temperature and / or humidity of the airflow at the air outlet of the hairdryer and a portion of the airflow can be recirculated based on the output of the sensor (MS). The hairdryer can have a nozzle to direct hot air towards a user's scalp. A wall of the drying chamber (HC) can be shaped to style hair and / or increase the contact area in contact with the hair.

Description

Background Art

[0001] US4118874A discloses a hair dryer having an internal duct connected to a centrifugal fan at one end and to a hood at the other end, and an external duct. The fan draws air through the internal duct and blows it toward the hood through the external duct. A grille for supporting long hair is located in the internal duct, so that air drawn toward the fan is drawn through any long hair on the grille.

[0002] KR20160024677A discloses a hair dryer for long hair that holds and dries long hair isolated from the outside world to maximize drying efficiency. The hair dryer comprises: a housing having a handle formed on an outer surface of one side and a hair holding space formed with a predetermined depth, wherein hair can be introduced through an opening at the upper portion for holding; a blower mounted at the lower portion of the housing for drawing in and blowing outside air into the hair holding space; a blowing induction portion for blowing air blown by the hair dryer toward the inner wall surface of the housing toward the periphery of the hair held in the hair holding space; and a heating device mounted on the side of the blower from which air is discharged to heat the blown air.

[0003] US2016150864A1 discloses a hair combing system comprising a vacuum tank, a hose, and a handheld unit. The hose is fixed to the vacuum tank and the handheld unit and is in fluid communication therewith. The handheld unit includes a vacuum chamber. A mechanism for generating a vacuum is located in the vacuum tank, and the vacuum is communicated with the vacuum chamber via the hose. The system may further include a heating element and a fan, which are arranged to heat air and move the air into the vacuum chamber. In one embodiment disclosed herein, a method for combing hair comprises the following steps: placing a portion of hair in a vacuum chamber; evacuating the hair to remove excess water; and applying heated air to a section of the hair. Summary of the Invention

[0004] The object of the present invention is, inter alia, to provide an improved hair dryer. The invention is defined by the independent claim. Advantageous embodiments are defined in the dependent claims.

[0005] The cross-section of the drying chamber has a first dimension in a first direction that is at least five times greater than a second dimension in a second direction perpendicular to the first direction, wherein the first and second directions are perpendicular to the direction of airflow in the drying chamber. Thus, the drying chamber is oval or even flat. Compared to a drying chamber with a circular cross-section, this provides the advantage that the hair is spread out across the width of the drying chamber, resulting in a more even drying. With a circular drying chamber, the hair in the middle of the hair bundle will remain moist while the hair on the outside of the hair bundle will dry. If the settings are adjusted so that the hair in the middle is also fully dried, the hair on the outside of the hair bundle will be exposed to too much heat, which could damage the hair.

[0006] Preferably, the first dimension is at least 10 times larger than the second dimension.

[0007] A compact hair dryer design is obtained if the drying chamber is folded, with the drying chamber having a U-shaped turn in the direction of the air flow.

[0008] If the first area of ​​the cross section of the drying chamber at the U-turn is smaller than the second area of ​​the cross section between the hair inlet and the U-turn, the air velocity is locally increased, which facilitates the entry of the hair into the device. With a smaller cross section, the radius of the turn can also be increased, which in turn makes it easier for the hair to form a U-turn without deformation or undesirable curling.

[0009] A more satisfying hair drying experience is obtained if the hair dryer is arranged to heat the hair from multiple sides.

[0010] The drying speed is also increased if the walls of the drying chamber have a material that is hydrophilic or absorbs water or reduces the surface tension of water.

[0011] If the water-absorbing material can be regenerated by hot air, the material can be used multiple times.

[0012] If the drying chamber is openable, the drying chamber can be cleaned.

[0013] If the hair dryer has a sensor for sensing the temperature and / or humidity of the air flow at the air outlet of the hair dryer, and part of the air flow is recirculated based on the output of the sensor, the air flow can be controlled to obtain the best results in terms of speed and hair feel, and this can be achieved with less heater power.

[0014] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 An embodiment of a hair dryer according to the invention is shown in cross section.

[0016] Figure 2Another view of a hair dryer according to the invention is shown. DETAILED DESCRIPTION

[0017] like Figure 2 As best shown, the inlet I1 for hair and cold air is wide, similar to a mailbox sleeve. The wide inlet I1 of the drying chamber evenly distributes the hair, preventing the middle of a lock from drying poorly. The circular curve at the hair inlet I1 bends the hair into the device due to the Coanda effect. In a preferred embodiment, the dimensions of the hair inlet I1 range from 5 mm x 50 mm to 20 mm x 250 mm. In a practical example, the inlet I1 measures 10 mm x 120 mm.

[0018] Although the hair inlet I1 can be straight, in a preferred embodiment, the shape of the hair inlet I1 follows the contour of the user's head to allow more hair to enter the drying chamber. The hair inlet I1 can therefore be curved. In an alternative embodiment, the hair inlet I1 can be V-shaped.

[0019] In the illustrated embodiment, the drying chamber is formed by a folded hair channel HC, into which hair enters (downward), then makes a U-turn upward around a first circular edge E1, and then makes a U-turn downward around a second circular edge E2. In this way, the 60 cm long hair path required by customers with long hair can be fitted into a compact device that is only about 20 cm high. At edges E1 and E2, the cross-sectional area can be smaller than the idle cross-sectional area between the edges, thereby locally increasing the air velocity to help pull the hair through the U-turn and ensure that the U-turn is more rounded, which also helps to allow the hair to pass through the U-turn in the hair channel HC. In a less complex embodiment, the drying chamber has only one U-turn.

[0020] The inner wall of the drying chamber can be equipped with dimples, because the air flow is limited and the dimples can reduce the resistance. The dimples also help to improve the heat exchange.

[0021] Preferably, the walls of the drying chamber HC are shaped to shape the hair and / or increase the contact area with the hair. The hair channel 11C may include ribs for spreading or even shaping the hair, and may include swirl ribs that can be set to produce a curling effect. If the walls of the hair channel are hot, such ribs increase the contact area with the hair, thereby accelerating the drying process.

[0022] At the end of the drying chamber, a filter FT prevents hair from entering the fan F. The filter FT is preferably removable to allow cleaning.

[0023] The suction fan F can be set to a high or low flow rate. The fan F should be able to handle minimal amounts of water / humidity. The fan F can generate an airflow between 5 and 40 l / s, preferably between approximately 18 and 20 l / s; fans used in some vacuum cleaners may be suitable for this purpose. Preferably, a single motor / fan unit is used to generate suction, which not only pulls hair into the hair passage HC but also draws air through or along the heater HT into the hair passage HC.

[0024] In the embodiment shown, hot air is provided to the hair that has entered the hair dryer only from one side (i.e. from the right side in the figure).In another embodiment, hot air is provided to the hair from both the left and right sides.

[0025] In the embodiment shown, the heater HT is shown on the right side of the folded hair channel HC. In other embodiments, when viewed from the Figure 1 From a human perspective, the heater HT is placed elsewhere, for example at the bottom, or before or after the folded hair channel, such as Figure 1 shown.

[0026] Alternatively and / or additionally to the suction fan F that draws hair into the hair channel at the end of the hair channel HC, a fan may be provided in a separate channel in which the heater HT is placed in order to generate an air flow in the hair channel HC that guides the hair into the hair channel.

[0027] As shown in our co-pending application EP 20173773.1 (attorney reference number: 2020PF00319), the hair channel HC may have multiple hot air inlets along its trajectory to ensure a more even distribution of heat over the length of the hair, thereby ensuring a more even drying rate.

[0028] After the fan F there is an outlet O for the moist air. If the hair dryer is provided with a heater HT, the outlet air is hot and can be used to dry the scalp. For this purpose, the outlet air should be directed towards the scalp.

[0029] Just before the filter FT, or between the filter FT and the fan F, there can be a sensor MS to measure moisture and / or temperature, which are related to the dryness of the hair. Based on the reading from the sensor MS, some of the outlet air from the fan F can be redirected towards the heater HT via a valve V2 to ensure that the air flows along the heater HT. This recirculation can save energy (because the heat in the outlet air is not wasted but reused), which is particularly important for battery-operated hair dryers. However, the air flow should allow sufficient cooling of the heater HT. However, the recirculated air may have too much moisture to ensure that the hair is dried in a satisfactory manner, so if the sensor MS indicates that the air contains too much moisture, the air is not recirculated or is only recirculated to a limited extent by appropriately controlling the valve V2. Based on the reading from the humidity sensor MS, the hair dryer can indicate that the hair has been sufficiently dried, for example by a beeping sound.

[0030] If the heater HT is of the type that provides hot air to the hair, the outlet of the air channel in which the heater HT is located is positioned at the beginning of the hair channel HC, near the hair inlet I1. The airflow is balanced so that enough air passes through the heater to cool it and provide hot air to the hair. For example, approximately 50% of the airflow in the hair channel passes through the hair inlet, and approximately 50% of the airflow in the hair channel comes from the channel or channels in which the heater HT is located. Once the hair closes off the hair inlet I1, the hot air ratio increases. To ensure that a sufficient amount of hot air is applied to the hair, a mechanism can be provided to narrow the inlet I1 once the hair has entered the hair dryer, thereby allowing less cold air to enter the hair dryer through inlet I1. In situations where there is no recirculation, or insufficient recirculation, to ensure sufficient airflow to cool the heater HT and provide a sufficient amount of hot air to the hair, the air channel in which the heater HT is located can have its own cold air inlet I2.

[0031] The heater HT can be controlled by a temperature switch. The temperature in the hair channel 11C is preferably about 70°C to 100°C. The heater HT can be a conventional (coil / ceramic) heater. The heater HT can have a power between 1000W and 2500W, for example a 1600W or 2100W heater, as used in conventional hair dryers.

[0032] If the HT heater is element-based, it can be placed along the hair channel wall (e.g., a PTC heater / thin film heater). Similarly, the surface can have dimples to improve heat exchange. When all the heat flows along the hair, the heater capacity can be smaller. Lower heater wattage allows for cordless, i.e., battery-operated, devices because of better efficiency.

[0033] If the heater HT is based on light radiation, the entire hair channel HC can be made transparent / mirrored to allow all light to pass through and hit the hair multiple times. As described in our co-pending application WO2019 / 048357 (attorney reference number: 2017PF02405), the heat generated by the LED unit is preferably reused to heat the hair, for example by an air flow that has passed through the LED unit or its cooling body.

[0034] If the heater HT is switched off and cools down, as indicated by the temperature sensor TS1 , the valve V1 at the outlet of the hot air channel can be closed to ensure that the suction through the inlet I is increased.

[0035] There may be an IR sensor inside to measure the temperature of the hair. Other sensors may be added, such as a camera that allows the settings of the fan F and / or heater HT and / or any ionizer to be adjusted based on analysis (possibly involving artificial intelligence) of the images taken by the camera.

[0036] If the hair dryer is battery powered, the battery may be cooled by the air in the hair channel HC.

[0037] A hair dryer can be connected using the IoT. For example, the device can have a Bluetooth connection to a smartphone with an app, allowing the device to be controlled via the smartphone. This makes sense when using a hair dryer as a desktop device placed on a table behind the user, making any controls on the hair dryer inaccessible. The device can have a user interface. The hair dryer can be handheld, with or without a power cord. The device can be placed on a table and angled.

[0038] The inner wall of the hair channel HC is preferably provided with a water-absorbing material for absorbing water and / or a covering of a material for destroying / reducing the surface tension of water droplets to increase the drying rate. Preferably, the water-absorbing material can be regenerated by passing hot air through the hair channel in the absence of hair.

[0039] Alternatively, the hair may be dried without application of hot air, ie by using ultrasound, as described, for example, in EP 3416521 B1 (Attorney Reference: 2016PF00205).

[0040] Hair health can be measured by measuring friction as the hair is pulled out in the manner shown in our co-pending application WO2019 / 057575 (attorney reference number: 2017PF02274).

[0041] In one embodiment, the hair dryer has a nozzle to direct hot air (eg, outlet air) toward the user's scalp to dry the scalp while the hair is being dried, which provides a spa-like experience.

[0042] It should be noted that the above embodiments illustrate rather than limit the present invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed in brackets should not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps other than those listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. Measures recited in mutually different dependent claims may be advantageously combined.

Claims

1. A hair dryer, comprising: Fan (F), used to generate airflow; as well as a drying chamber (HC) having a hair inlet (I1) into which hair can be guided by the air flow; The cross section of the drying chamber (HC) has a first dimension in a first direction, the first dimension is at least 5 times larger than a second dimension in a second direction, the second direction is perpendicular to the first direction, and the first direction and the second direction are both perpendicular to the direction of the airflow.

2. The hair dryer of claim 1, wherein the first dimension is at least 10 times larger than the second dimension.

3. Hair dryer according to claim 1, wherein the drying chamber (HC) is folded such that it has a U-shaped turn in the direction of the air flow.

4. Hair dryer according to claim 2, wherein the drying chamber (HC) is folded such that it has a U-shaped turn in the direction of the air flow.

5. A hair dryer according to claim 3, wherein a first area of ​​the cross section of the drying chamber (HC) at the U-turn is smaller than a second area of ​​the cross section located between the hair inlet (I1) and the U-turn.

6. A hair dryer according to claim 4, wherein a first area of ​​the cross section of the drying chamber (HC) at the U-turn is smaller than a second area of ​​the cross section located between the hair inlet (I1) and the U-turn.

7. A hair dryer according to any one of claims 1 to 6, wherein the hair inlet (I1) of the drying chamber (HC) is shaped to follow the contour of a user's head.

8. A hairdryer according to any one of claims 1 to 6, wherein the hairdryer is arranged for heating the hair from multiple sides.

9. Hairdryer according to any one of claims 1 to 6, wherein the walls of the drying chamber (HC) are provided with a hydrophilic material or a water-absorbing material or a material that reduces the surface tension of water.

10. The hair dryer according to claim 9, wherein the water-absorbing material can be regenerated by hot air.

11. Hair dryer according to any one of claims 1 to 6 and 10, wherein the drying chamber (HC) is openable so that it can be cleaned.

12. A hair dryer according to any one of claims 1-6 and 10, wherein the hair dryer has a sensor (MS) for sensing the temperature and / or humidity of the air flow at the air outlet of the hair dryer, and wherein part of the air flow is recirculated based on the output of the sensor.

13. The hair dryer of any one of claims 1-6 and 10, wherein the hair dryer has a nozzle to direct hot air toward the user's scalp.

14. Hairdryer according to any one of claims 1-6 and 10, wherein the walls of the drying chamber (HC) are shaped to style the hair and / or to increase the contact area with the hair.

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