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. In general, the hair iron includes an arrangement of two hair styling components. The 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. Usually, in such an arrangement, the hair styling components are hinged to each other. Furthermore, it is practical if the hair styling components have a substantially plate-like appearance and the hair styling surfaces of the hair styling components have a substantially 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 an open position, placing the hair iron against the hair so that the hair strand is received in the arrangement 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 obtain and / or process information about the hair. Some advanced hair irons have been proposed to measure the moisture content of the hair, but this is done using a component temperature sensor that detects the temperature of the hair styling components, which is not accurate 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 the 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 moisture content of the hair 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 moisture content of the hair and making the moisture content reading less reliable.

[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 comprising 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 and 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 an inferred moisture content of the hair from the detected hair temperature.

[0007] From the above definitions, it follows that the 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 considering the moisture content of the hair can be automatically selected and realized, so that the user of the hair styling device does not have 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 allows the user to manually adjust the temperature setting. When a 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 a parameter and / or calculated values ​​of related parameters to moisture content of the hair under various circumstances, e.g., for various known moisture levels of hair.

[0010] The 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 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 the component temperature sensor may detect the temperature of the hair styling component at the location of the hair styling surface of the hair styling component, but the component temperature sensor may also detect the temperature at the location of another area of ​​the hair styling component. Although the determining factor of the hair styling process is the temperature at the location of the hair styling surface, it is not necessary to detect the surface temperature directly, given that the temperature at another area of ​​the hair styling component is related to the surface temperature, and the trend of the temperatures detected at the other areas represents the trend of 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. It may be practical if the hair styling surface of the hair styling component actually contacts the hair in the styling action, but 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, it may comprise a pressure sensor for detecting a 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 involving this value in 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 depending on the clamping pressure as further factors other than the temperature of the hair styling components and the temperature of the hair, and possibly also 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 an input from the position detector, derives a value representative of the duration of the styling action from the input from the position detector, and participates in 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 only active 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 representative of 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 situations and includes a switching mechanism that switches from one situation to another situation 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 providing an indication of the moisture content of the hair. [Brief description of the drawings]

[0018] The invention is 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. [Diagram 2] FIG. 2 is a graph combining the detected temperature of the hair styling component and the hair temperature versus time. [Diagram 3] FIG. 3 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. [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 PREFERRED EMBODIMENTS

[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 with a first hair styling component 11 with a first hair styling surface 12 and a second hair styling component 13 with a second hair styling surface 14. The first hair styling component 11 and the second hair styling component 13 are hinged to each other, allowing 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 hair styling 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 an 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 can also be applied to other types of hair styling devices.

[0022] The hair styling device 1 further comprises a heating mechanism 20 for heating both the first hair styling component 11 and the second hair styling component 13. The heating mechanism 20 is shown in Fig. 1 only diagrammatically as two dashed boxes each associated with one of the hair styling components 11, 13. The present description is also applicable to the alternative in which the heating mechanism 20 heats only one of the hair styling components 11, 13. As is generally known from the field of manual hair irons, the proper use of the hair styling device 1 shown in the figures involves the actions of a user i) picking up a hair strand in a position close to the scalp (this is done with the device 10 in an open position), ii) putting the device 10 in a 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 that 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 a heated state. A strand of hair is 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 in 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 called the 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 called the hair temperature sensor 22. The detection range of the 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 analyses the moisture content of the hair undergoing a 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 may be practical if the controller 23 is implemented as 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 comprises a position detector 24 for detecting the position of the device 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 the 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 de-triggered. 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 the hair moisture analysis, as will be explained with reference to the graphs of figures 2, 3 and 4.

[0025] FIG. 2 is a graph of combined hair styling component temperature and hair temperature detection values ​​versus time. These values ​​are obtained during a typical straightening stroke on healthy Chinese hair with normal moisture content (i.e., about 11% moisture content) at a temperature setting of 200° C. In the combined value graph, temperature is expressed in degrees Celsius and time is expressed in seconds. The detected hair styling component temperature is the high value in the graph and the detected hair temperature is the low value in the graph. In this graph, the following values ​​that can be used in the hair moisture analysis are: stroke duration t, difference ΔT between the 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 manner in which the temperature of the hair styling component drops during the straightening stroke are not known. The accuracy of the estimation is greatly improved by having at least the hair temperature information. Using a combination of parameters obtained 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, it is possible to accurately estimate whether the moisture content of the hair is higher than normal, normal, or lower than normal. In this regard, it is noted that FIG. 3 is a graph combining the detected values ​​of the temperature of the hair styling component and the hair temperature against time for a straightening stroke performed at 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 temperature of the hair styling component and the hair temperature against time for a straightening stroke performed at normal speed and a temperature setting of 200° C. on hair with a 5% increase in moisture level. In the graphs of FIG. 3 and FIG. 4, the temperature is expressed in degrees Celsius and the time is expressed in seconds, similar to the graph of FIG. 2. The scale on the left hand side of the graphs in Figures 3 and 4 relates to the temperature of the hair styling component and the scale on the right hand side of the graphs in Figures 3 and 4 relates to the hair temperature. Further, in the graphs in Figures 3 and 4, similar to the graph in Figure 2, the sensed values ​​of the hair styling component temperature are the higher values ​​on the graph and the sensed values ​​of the hair temperature are the lower values ​​on the graph.

[0027] The following table applies to a comparison of the graphs of FIG. 3 and FIG. 4. The data relevant to the situation to which the graph of FIG. 3 applies is considered the baseline data. In this table, the temperature of the hair styling component is T c and the hair temperature is T h This indicates that. [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 the user's behavior, such as differences in stroke speed and clamping pressure, should also be considered. Once the characterization is completed, a data direction matrix is ​​obtained and pre-programmed as a look-up table in the controller 23. This look-up table is used in the process of generating an output indicative of the moisture content of the hair. By collecting detection data during the actual styling action and comparing this data with the data direction matrix, it is possible to accurately indicate the moisture content of the hair subjected to the styling action. This indication number 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 inform the user. With regard to the latter option, it is 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 a suitable app installed. The user may be informed by a simple message mentioning the moisture content of the hair, or by a more sophisticated message detailing how to best treat the hair, the products that may be used for this, etc.

[0029] It will be clear to those skilled in the art that the scope of the present invention is not limited to the above examples, and that several amendments and modifications 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 figure, an accelerometer may be used to detect the use condition. It is intended that the present invention be construed as including all such amendments and modifications insofar as they are 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 as 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 present invention may be omitted, and are not necessarily drawn 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 can be combined with elements and features of the 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 "including" 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 in this text to "hair styling component temperature" or "hair styling component temperature" should be understood in relation to temperature detection on or in the hair styling component by a component temperature sensor. Similarly, references in this text 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 a styling action by said hair styling device; a heating mechanism for heating the hair styling element; a component temperature sensor for detecting a 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 characterized in that it derives 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 inferred 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 the 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 a 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. A hair styling device according to claim 1 , wherein the hair temperature sensor is of the non-contact type.

5. 5. A hair styling device according to claim 1, further 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, the controller including said pressure signal in processing the inputs for controlling the operation of the heating mechanism.

6. 6. A hair styling device according to claim 1, further comprising a detector for detecting usage of the hair styling component, the controller receiving a usage signal from the detector, deriving from the usage signal a value representative of a duration of a styling action and involving said value in processing the inputs for controlling operation of the heating mechanism.

7. 7. The hair styling device of claim 6, wherein the detector comprises a switching mechanism configured to be in one of at least two different conditions, the switching mechanism switching from one condition to another condition upon a change in position of the hair styling component.

8. 8. A hair styling device according to any one of the preceding claims, comprising an indicator configured to provide a person with information including information related to the moisture content of the hair based on the input.

Images