Hair Styling Devices

Abstract

The hair styling device 1 includes hair styling components 11, 13, a heating mechanism 20 for heating the hair styling components 11, 13, a component temperature sensor 21 for detecting the temperature of the hair styling components 11, 13, a hair temperature sensor 22 for detecting the temperature of the hair facing the hair styling components 11, 13 during operation of the hair styling device 1, and a controller 23 for receiving inputs from at least both temperature sensors 21, 22 and processing the inputs to control operation of the heating mechanism 20 and to derive a temperature setting for the hair styling components 11, 13 taking into account at least the moisture content of the hair inferred from the hair temperature.

Description

[Technical Field]

[0001] The present invention relates to a hair styling device that includes at least one hair styling element configured to face hair that is to be subjected to a styling action by the hair styling device, and a heating mechanism for heating the hair styling element. [Background technology]

[0002] An example of such a hair styling device is a hair iron. Typically, a hair iron includes an arrangement of two hair styling components. This arrangement can be in an open position, where the distance between at least a portion of the hair styling surfaces of the hair styling components is sufficient to insert hair between the hair styling surfaces, and in a closed position, where the distance between at least a portion of the hair styling surfaces of the hair styling components is minimal. Typically, in such an arrangement, the hair styling components are hinged to each other. Furthermore, it is practical if the hair styling components have a generally plate-like appearance and the hair styling surfaces of the hair styling components have a generally flat appearance.

[0003] When the hair iron is activated, the hair styling components are heated. Performing a hair straightening action with the activated hair iron involves ensuring that the arrangement is in the open position, placing the hair iron against the hair so that the hair strand is received within the arrangement in a position close to the scalp, closing the arrangement so that the hair strand is captured between the hair styling surfaces of the hair styling components, and pulling the hair iron downwards on the hair strand. In this way, the hair strand is subjected to a heating action while the hair iron glides along the hair, resulting in the hair strand being straightened. Summary of the Invention [Problem to be solved by the invention]

[0004] Many known hair irons are configured only to perform the hair straightening function and are not configured to acquire and / or process information about the hair. While some advanced hair irons propose measuring the moisture content of hair, this is done using a component temperature sensor that detects the temperature of the hair styling components, which is inaccurate due to unknown factors such as clamping pressure between the hair styling surfaces, stroke speed, and ambient temperature. For example, when using a hair iron on a hair strand with normal moisture content, the component temperature sensor observes a certain temperature drop after a straightening stroke is performed. However, when the same hair strand is straightened at a lower ambient temperature, there is a larger temperature drop, even though the hair moisture content is the same. Similarly, when the clamping pressure is higher or the stroke speed is faster, the magnitude of heat loss at the hair styling surface increases, and the temperature drop observed by the component temperature sensor is higher, introducing deviations into the calculation of the hair moisture content, resulting in an unreliable moisture content reading.

[0005] The present invention aims to provide an improved hair styling device. The invention is defined by the independent claims. The dependent claims define advantageous embodiments. [Means for solving the problem]

[0006] In view of the foregoing, the present invention provides a hair styling device including at least one hair styling component having a hair styling surface facing hair that is to be styled by the hair styling device, a heating mechanism for heating the hair styling component, a component temperature sensor for detecting a temperature of the hair styling component, a hair temperature sensor for detecting a temperature of hair facing the hair styling surface during operation of the hair styling device, and a controller for receiving inputs from at least both the component temperature sensor and the hair temperature sensor, processing the inputs to control operation of the heating mechanism, and for deriving a temperature setting for the hair styling component taking into account at least a moisture content of the hair estimated from the detected hair temperature.

[0007] From the above definitions, it follows that a hair styling device according to the present invention includes not only a component temperature sensor but also a hair temperature sensor. A controller of the hair styling device receives inputs from at least both the component temperature sensor and the hair temperature sensor, processes the inputs, and controls the operation of the heating mechanism. In this way, a temperature setting of the hair styling component that is appropriate given the moisture content of the hair can be automatically selected and realized, thereby eliminating the need for a user of the hair styling device to think about the temperature setting.

[0008] The present invention is also directed to options where the hair styling device includes an indicator that provides a person with information, including information regarding the moisture content of the hair, based on input, and / or options where the temperature setting can be manually adjusted. Once the user is provided with information regarding the moisture level of the hair, the user can make well-informed decisions regarding which styling temperature setting to select, which hair care products to use, etc.

[0009] It may be useful if the controller is configured to involve a look-up table in generating the output indicative of the moisture content of the hair. Such look-up tables reflect the results of representative experiments conducted in the context of a hair styling device design process and are intended to relate detected values ​​of parameters and / or calculated values ​​of related parameters to moisture content of the hair under various circumstances, e.g., for various known moisture levels of the hair.

[0010] Detection of the hair temperature entails the interesting option of finding the start and end of the styling action, and thereby the duration of the styling action (assuming that valid hair temperature values ​​are only detected during the time when the hair is actually present on or near the hair styling surface of the hair styling component). With this in mind, the controller may derive a value representative of the duration of the styling action from the input from the hair temperature sensor and involve this value to control the operation of the heating mechanism.

[0011] Further, the controller derives from the inputs from the component temperature sensor and the hair temperature sensor one or more of: i) a value representing the temperature of the hair styling component at the start of the styling action; ii) a value representing the drop in temperature of the hair styling component during the styling action; iii) a value representing the drop in temperature of the hair during the styling action; iv) a value representing the peak temperature of the hair during the styling action; v) a value representing the peak temperature of the hair styling component during the styling action; and vi) a difference between the value representing the peak temperature of the hair during the styling action and the value representing the peak temperature of the hair styling component during the styling action, and engages one or more of these to control the operation of the heating mechanism.

[0012] The component temperature sensor may be of any suitable type and may be located at any suitable location on or within the hair styling device, in particular on or within the hair styling component. In this regard, it is noted that while the component temperature sensor may detect the temperature of the hair styling component at the hair styling surface of the hair styling component, the component temperature sensor may also detect the temperature at other areas of the hair styling component. While the temperature at the hair styling surface is determinative of the hair styling process, it is not necessary to directly detect the surface temperature, assuming that the temperatures at other areas of the hair styling component are related to the surface temperature and that trends in the temperatures detected in other areas represent trends in the surface temperature.

[0013] Although the hair temperature sensor may be non-contact, the present invention also covers the possibility of using a hair temperature sensor that detects the temperature of hair that is actually in contact with the sensor. The same applies to the hair styling surface of the hair styling component. While it may be practical if the hair styling surface of the hair styling component actually contacts the hair in the styling action, the fact remains that the hair styling surface of the hair styling component can perform a styling action on hair that is some distance away from the hair styling surface, for example, by emitting heat towards the hair. The hair styling component may be of any suitable design. For example, the hair styling component has a generally plate-like appearance and the hair styling surface has a generally flat appearance.

[0014] In a practical embodiment, the hair styling device according to the invention comprises an arrangement of two hair styling components, which can be in an open position, in which the distance between at least a portion of the hair styling surfaces of the hair styling components is sufficient to insert hair between the hair styling surfaces, and in a closed position, in which the distance between at least a portion of the hair styling surfaces of the hair styling components is minimal. In particular, said arrangement can achieve a styling action aimed at straightening hair, so that the hair styling device can be used as a hair iron.

[0015] When the hair styling device includes the above arrangement, the hair styling device may comprise a pressure sensor that detects the clamping pressure between the hair styling surfaces in a closed position of the above arrangement, the controller receiving an input from the pressure sensor, the controller deriving from the input from the pressure sensor at least one value representative of at least one pressure parameter of the styling action and contributing this value to generating an output indicative of the moisture content of the hair. In such a case, the accuracy of the moisture content estimation may be further improved by relying on the clamping pressure as an additional factor beyond the temperature of the hair styling components and the temperature of the hair, and possibly also on the duration / speed of the styling action.

[0016] The hair styling device may have a position detector that detects the position of the hair styling component. In this case, it is advantageous if the controller receives input from the position detector, derives a value representing the duration of the styling action from the input from the position detector, and contributes this value to generating an output indicative of the moisture content of the hair. Also in this case, it is possible to electrically couple a hair temperature sensor to the position detector so that it is active only when the functional arrangement is in the closed position and is deactivated otherwise. In such a configuration, it is relatively easy to implement the aforementioned option of deriving a value representing the duration of the styling action from the input from the hair temperature sensor. An example of a position detector is a detector that is configured to be in one of at least two different states and includes a switching mechanism that switches from one state to another state when the position of the arrangement changes.

[0017] These and other aspects of the present invention will be apparent from and will be explained with reference to the following detailed description of a practical embodiment of a hair styling device that is an electronically controlled hair iron that provides an indication of the moisture content of the hair. [Brief explanation of the drawings]

[0018] The invention will be explained in more detail below with reference to the figures.

[0019] [Figure 1] FIG. 1 illustrates a perspective view of a practical embodiment of a hair styling device according to the invention. [Figure 2] FIG. 2 is a graph combining the detected hair styling component temperature and hair temperature values ​​over time. [Figure 3] FIG. 3 is a graph combining the detected hair styling component temperature and hair temperature values ​​over time, showing the effect on the detected hair moisture level under otherwise similar conditions. [Figure 4]FIG. 4 is a graph combining the detected hair styling component temperature and hair temperature over time, showing the effect on the detected hair moisture level under otherwise similar conditions. DETAILED DESCRIPTION OF THE INVENTION

[0020] FIG. 1 shows a practical embodiment of a hair styling device 1 according to the invention.

[0021] The hair styling device 1 comprises an apparatus 10 having a first hair styling element 11 with a first hair styling surface 12 and a second hair styling element 13 with a second hair styling surface 14. The first hair styling element 11 and the second hair styling element 13 are hinged to one another, allowing for an open position of the apparatus 10 for receiving hair between the first hair styling surface 12 and the second hair styling surface 14, and a closed position for styling hair between the first hair styling surface 12 and the second hair styling surface 14. Figure 1 shows the hair styling device 1 with the apparatus 10 in the open position. The hair styling device 1 shown in the figures is particularly suitable for use as a manual hair iron, although this does not alter the fact that the invention is also applicable to other types of hair styling devices.

[0022] The hair styling device 1 further includes a heating mechanism 20 that heats both the first hair styling element 11 and the second hair styling element 13. The heating mechanism 20 is shown in FIG. 1 only diagrammatically as two dashed boxes, each associated with one of the hair styling elements 11, 13. The present description is also applicable to the alternative in which the heating mechanism 20 heats only one of the hair styling elements 11, 13. As is commonly known from the field of manual hair irons, proper use of the hair styling device 1 shown in the figures involves the user i) picking up a hair strand in a position close to the scalp (this is done with the device 10 in the open position), ii) putting the device 10 in the closed position with the hair sandwiched between the hair styling surfaces 12, 14, and iii) pulling the hair styling device 1 downwards over the hair strand. Assuming these actions are performed with the hair styling device 1 in an active state, the hair styling surfaces 12, 14 can slide over the hair strand in the heated state. The hair strands are sandwiched between the hair styling surfaces 12, 14 to achieve the desired hair straightening effect.

[0023] The hair styling device 1 comprises two temperature sensors 21, 22 integrated into one of the hair styling components 11, 13. One of these temperature sensors 21, 22 detects the temperature of the corresponding hair styling component 11, 13 and is referred to as component temperature sensor 21. The other of these temperature sensors 21, 22 detects the temperature of the hair in a non-contact manner and is referred to as hair temperature sensor 22. The detection range of hair temperature sensor 22 is shown in FIG. 1 as a cone-shaped area. The hair styling device 1 further comprises a controller 23. The controller 23 controls the operation of the heating mechanism 20 based on inputs representing the desired temperature settings of the hair styling components 11, 13 and inputs from the component temperature sensor 21 representing the actual temperatures of the hair styling components 11, 13. In FIG. 1, the controller 23 is shown only diagrammatically as a dashed box. The controller 23 also analyzes the moisture content of the hair undergoing styling action by the hair styling device 1 based at least on the hair temperature measurements, as will be explained in more detail below. For example, it is practical if the controller 23 is configured with a microprocessor.

[0024] In the illustrated embodiment, the hair styling device 1 not only has a temperature sensing function but also a position sensing function. That is, the hair styling device 1 includes a position detector 24 that detects the position of the apparatus 10. The controller 23 receives and processes inputs from both temperature sensors 21, 22 and from the position detector 24. When the arrangement 10 is in the open position and the position detector 24 is not triggered, the controller 23 does not use the inputs from the temperature sensors 21, 22 for hair moisture analysis. When the position detector 24 is triggered, the temperature data received from the temperature sensors 21, 22 is recorded until the position detector 24 is untriggered. The recorded temperature data, together with the recorded times of styling actions / strokes of the hair styling device 1 on the hair strand, can then be used for hair moisture analysis, as will be explained with reference to the graphs in Figures 2, 3 and 4.

[0025] Figure 2 is a graph of combined hair styling component temperature and hair temperature readings versus time. These values ​​are obtained during a typical straightening stroke on healthy Chinese hair with normal moisture content (i.e., approximately 11% moisture content) at a temperature setting of 200°C. In the combined graph, temperature is expressed in degrees Celsius and time is expressed in seconds. The detected hair styling component temperature is the high value on the graph, and the detected hair temperature is the low value on the graph. In this graph, the following values ​​can be used in hair moisture analysis: stroke duration t, difference ΔT between peak values ​​of hair styling component temperature and hair temperature. p , the drop in hair styling component temperature during the stroke duration ΔT c , and the drop in hair temperature during the stroke duration ΔT h , is shown.

[0026] If only the temperature of the hair styling component is available, it is difficult to estimate the moisture level of the hair, since all the factors that contribute to the way the temperature of the hair styling component drops during the straightening stroke are unknown. The accuracy of the estimation is greatly improved by having at least the hair temperature information. By detecting both the temperature of the hair styling component and the hair temperature and comparing them with reference values ​​obtained in laboratory characterization tests, a combination of parameters can be used to accurately estimate whether the moisture content of the hair is higher than normal, normal, or lower than normal. In this regard, it should be noted that FIG. 3 is a graph combining the detected values ​​of the hair styling component temperature and hair temperature versus time for a straightening stroke performed at a normal speed and a temperature setting of 200°C on hair with normal moisture content. FIG. 4 is a graph combining the detected values ​​of the hair styling component temperature and hair temperature versus time for a straightening stroke performed at a normal speed and a temperature setting of 200°C on hair with a 5% increase in moisture level. In the graphs of FIGS. 3 and 4, temperature is expressed in degrees Celsius, and time is expressed in seconds, as in the graph of FIG. 2. The scales on the left side of the graphs in Figures 3 and 4 relate to hair styling component temperature, and the scales on the right side of the graphs in Figures 3 and 4 relate to hair temperature. Furthermore, in the graphs in Figures 3 and 4, similar to the graph in Figure 2, the detected hair styling component temperature is the high value on the graph, and the detected hair temperature is the low value on the graph.

[0027] The following table applies to a comparison of the graphs of Figure 3 and Figure 4. Data relating to the situation to which the graph of Figure 3 applies is considered the baseline data. In this table, the temperature of the hair styling component is taken as T c and the hair temperature is T h This indicates: [Table 1]

[0028] Characterization of the parameters listed in the table is first performed in a laboratory using hair with normal moisture content, hair with low moisture content, and hair with high moisture content. Ideally, factors related to user behavior, such as differences in stroke speed and clamp pressure, should also be considered. Once characterization is complete, a data direction matrix is ​​obtained and pre-programmed as a lookup table within the controller 23. This lookup table is used in the process of generating an output indicative of the moisture content of the hair. By collecting sensory data during an actual styling action and comparing this data with the data direction matrix, an accurate indication of the moisture content of the styling-affected hair can be obtained. This displayed value can be used, for example, to adjust the operation of the heating mechanism 20 regardless of the temperature setting initially selected by the user, and / or to notify the user. Regarding the latter option, it should be noted that the hair styling device 1 may be equipped with a display or other type of indicator and / or configured to communicate moisture content-related information to an external device, such as a smartphone with an appropriate app installed. The user is notified by a simple message mentioning the moisture content of the hair, or a more sophisticated message detailing how to best treat the hair and the products that may be used to do so.

[0029] It will be apparent to those skilled in the art that the scope of the present invention is not limited to the above examples, and that several modifications and alterations are possible without departing from the scope of the present invention as defined in the appended claims. For example, although the above embodiment relates to a hair iron, the present invention can be advantageously applied to a heated straightening brush. Instead of the position detector 24 shown in the figures, an accelerometer may be used to detect the operating conditions. The present invention is intended to be construed as including all such modifications and alterations insofar as they come within the scope of the claims or their equivalents. While the present invention has been illustrated and described in detail in the drawings and description, such illustration and description should be considered illustrative or exemplary only, and not restrictive. The present invention is not limited to the disclosed embodiments. The drawings are schematic, and details not necessary for understanding the invention may be omitted, and the drawings are not necessarily to scale.

[0030] Variations of the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the figures, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other steps or elements, and the word "a" or "an" does not exclude a plurality of elements. Any reference signs in the claims should not be construed as limiting the scope of the invention.

[0031] Elements and features described with respect to or in connection with a particular embodiment may be combined with elements and features of other embodiments as appropriate, unless expressly stated otherwise. Thus, the mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0032] The terms "having" and "including" as used in this text will be understood by those skilled in the art as encompassing the term "consisting of." Thus, the terms "having" or "comprising" may mean "consisting of" in the context of one embodiment, but in another embodiment may mean "containing / having / comprising at least the defined species and optionally one or more other species." The expressions "configured to" and "arranged to" have the same meaning.

[0033] References herein to "hair styling component temperature" or "hair styling component temperature" should be understood in relation to temperature detection on or within the hair styling component by a component temperature sensor. Similarly, references herein to "hair temperature" or "hair temperature" should be understood in relation to hair temperature detection by a hair temperature sensor.

[0034] Important aspects of the present invention are as follows: The hair styling device 1 comprises hair styling components 11, 13, a heating mechanism 20 for heating the hair styling components 11, 13, a component temperature sensor 21 for detecting the temperature of the hair styling components 11, 13, a hair temperature sensor 22 for detecting the temperature of the hair facing the hair styling components 11, 13 during operation of the hair styling device 1, and a controller 23 for receiving inputs from at least both temperature sensors 21, 22 and processing the inputs to control operation of the heating mechanism (20).

Claims

1. 1. A hair styling device comprising: a hair styling element facing the hair that is to be subjected to the styling action by said hair styling device; a heating mechanism for heating the hair styling element; a component temperature sensor for detecting the temperature of the hair styling component; a hair temperature sensor for detecting the temperature of hair facing the hair styling element during operation of the hair styling device; a controller that receives inputs from at least both the component temperature sensor and the hair temperature sensor, and processes the inputs to control operation of the heating mechanism; 1. A hair styling device comprising: The controller is further configured to derive a temperature setting for the hair styling component taking into account at least the detected temperature of the hair and a moisture content of the hair estimated from the detected temperature of the hair styling component.

2. 2. The hair styling device of claim 1, wherein the controller derives a value representative of a duration of a styling action from the input from the hair temperature sensor and involves said value in processing said input to control operation of the heating mechanism.

3. The controller, from the inputs from the component temperature sensor and the hair temperature sensor, a value representing the temperature of the hair styling component at the start of the styling action; a value representing the drop in temperature of the hair styling component during the styling action; a value representing the drop in temperature of the hair during the styling action; a value representing the peak temperature of the hair during the styling action; a value representing the peak temperature of the hair styling component during the styling action; and the difference between a value representing the peak temperature of the hair during the styling action and a value representing the peak temperature of the hair styling component during the styling action; Derive one or more of 3. A hair styling device according to claim 1 or 2, wherein said one or more of these are involved in processing said inputs to control the operation of said heating mechanism.

4. 4. A hair styling device according to any one of claims 1 to 3, wherein the hair temperature sensor is of the non-contact type.

5. 5. A hair styling device according to any one of claims 1 to 4, comprising a pressure sensor for detecting a clamping pressure between hair styling surfaces of the hair styling elements, the controller receiving a pressure signal from the pressure sensor and involving the pressure signal in processing the inputs for controlling the operation of the heating mechanism.

6. 6. A hair styling device according to any one of claims 1 to 5, comprising a detector for detecting usage of the hair styling component, wherein the controller receives a usage signal from the detector, derives from the usage signal a value representative of the duration of a styling action, and involves said value in processing the inputs to control operation of the heating mechanism.

7. 7. The hair styling device of claim 6, wherein the detector includes a switching mechanism configured to be in one of at least two different states, the switching mechanism switching from one state to another state when the position of the hair styling component changes.

8. 8. A hair styling device according to any one of claims 1 to 7, comprising an indicator that provides a person with information based on said input, including information related to the moisture content of the hair.

Images