WO2020120348A1

WO2020120348A1 - Hair stylying device

Info

Publication number: WO2020120348A1
Application number: PCT/EP2019/084113
Authority: WO
Inventors: Chuen Yu Cyrus PANG; Martina HOLZMANN; Ype Bernardus BRADA; Petrus Johannes Bremer
Original assignee: Koninklijke Philips N.V.
Priority date: 2018-12-10
Filing date: 2019-12-09
Publication date: 2020-06-18
Also published as: CN210144047U; EP3893691B1; EP3893691A1; PL3893691T3; CN114206156A; KR20210099643A

Abstract

A device for hair styling comprises a first arm; a second arm coupled to the first arm; a temperature sensor configured to sense a temperature of hair and output a temperature signal indicative of the sensed temperature of hair; a state sensor configured to detect whether the first and second arms are opened or closed and output a state signal indicative of an open/close state of the first and second arms; and a controller configured to: in response to detecting a change in the open/close state of the first and second arms, identify a current styling operation; determine a variation in the temperature of hair between the current styling operation and a previous styling operation; and determine, based on the variation in the temperature of hair, a count that the device has operated on a same strand of hair, to thereby control the hair styling.

Description

HAIR STYLYING DEVICE

FIELD

Embodiments of the present disclosure relate to hair styling devices or appliances.

BACKGROUND

In hair care applications, it is desirable to analyze and assess hair condition and/or hair health. People usually associate styling the hair with high heat to hair damage. One way for assessing hair condition is to assess the actual strength of the hair. Currently, people have a rough measure for strength loss based on amount of hair found on brush, bed, and so on. However, this measure is very rough and often cannot have an explicit indication until the hair has been severely damaged.

Tensile stress measures the tensile strength properties and is used in hair care and cosmetics industry to measure effects of topical application, chemical treatment, or the like. The tensile strength properties are correlated with cortical properties and are not so much related to the cuticle. This measurement allows understand if the core is damaged by heat, chemical and so on. However, this requires a specific device for measurement.

Accordingly, there is a requirement for an improved approach for estimating hair condition in the art

SUMMARY

In general, example embodiments of the present disclosure provide methods and devices for hair styling.

In a first aspect, there is provided a method of operating a device for hair styling. The method comprises in response to detecting a change in an open/close state of arms of the device, identifying a current styling operation; determining a variation in temperature of hair between the current styling operation and a previous styling operation; and determining, based on the variation in temperature of hair, a count that the device has operated on a same strand of hair, to thereby control the hair styling.

The method can provide a count of strokes on the same strand of hair during hair styling by recording hair temperature and counting the amount of times the device is opened and closed. In this way, the operator can learn the hair condition based on the count of strokes.

In some embodiments, identifying the current styling operation comprises: in response to detecting that the arms are opened, determining that the previous styling operation ends and the current styling operation starts; and in response to detecting that the arms are subsequently opened, determining that the current styling operation ends. By defining when the stroke starts and ends, the counter can determine the counts in a more accurate and efficient way.

In some embodiments, determining the variation in temperature comprises: determining a first average temperature of hair during the previous styling operation; determining a second average temperature of hair during the current styling operation; and determining a difference between the second average temperature and the first average temperature. The average temperature is a more stable measure of the hair temperature, although other characteristic temperature can also be used.

In some embodiments, determining the count comprises: in response to the variation indicating an increase in temperature from the previous styling operation to the current styling operation, incrementing the count; and in response to the variation not indicating an increase in temperature from the previous styling operation to the current styling operation, resetting the count to one. By designing a simple algorithm, the counter can determine the count of strokes on the same strand of hair without consuming much computation resource.

In some embodiments, the method further comprises in response to the count exceeding a predetermined threshold, turning off at least one heater of the device; and/or providing at least one of a visual or audible indication of the count.

In a second aspect, there is provided a device for hair styling. The device comprises a first arm; second arm coupled to the first arm; a temperature sensor configured to sense a temperature of hair and output a temperature signal indicative of the sensed temperature of hair; a state sensor configured to detect whether the first and second arms are opened or closed and output a state signal indicative of an open/close state of the first and second arms; and a controller configured to: receive the temperature signal from the temperature sensor and the state signal from the state sensor; in response to detecting a change in the open/close state of the first and second arms, identify a current styling operation; determine a variation in the temperature of hair between the current styling operation and a previous styling operation; and determine, based on the variation in the temperature of hair, a count that the device has operated on a same strand of hair, to thereby control the hair styling.

In some embodiments, the controller is configured to identify the current styling operation by: in response to detecting that the first and second arms are opened, determining that the previous styling operation ends and the current styling operation starts; and in response to detecting that the first and second arms are subsequently opened, determining that the current styling operation ends.

In some embodiments, the controller is configured to determine the variation in the temperature of hair by: determining a first average temperature of hair during the previous styling operation; determining a second average temperature of hair during the current styling operation; and determining a difference between the second average temperature and the first average temperature.

In some embodiments, the controller is configured to determine the count by: in response to the variation indicating an increase in temperature from the previous styling operation to the current styling operation, incrementing the count; and in response to the variation not indicating an increase in temperature from the previous styling operation to the current styling operation, resetting the count to one.

In some embodiments, the controller is further configured to: in response to the count exceeding a predetermined threshold, turning off at least one heater of the device; and/or providing at least one of a visual or audible indication of the count.

In some embodiments, the device further comprises a first heating plate disposed on a surface of the first arm; and a second heating plate disposed on a surface of the second arm opposite to the first heating plate.

In some embodiments, the temperature sensor comprises a first contactless temperature sensor arranged on the second arm having a field of view facing the first arm and configured to measure a temperature of an object within the field of view and/or a second contactless temperature sensor arranged on the first arm having a field of view facing the second arm and configured to measure a temperature of an object within the field of view.

By contactless temperature sensor, the temperature of the object such as hair can be measured in a direct way, which facilitates a more accurate assessment of hair condition and control of the device. In some embodiments, the temperature sensor is disposed in an aperture in the second heating plate. In this way, the device can take full advantage of its space, which facilitates miniaturization of the device.

In some embodiments, the temperature sensor comprises an infrared temperature sensor with an optical window for receiving infrared light and facing the first arm.

In some embodiments, the temperature sensor is arranged on a periphery of the first heating plate, and wherein the first heating plate comprises at least one slit between the temperature sensor and a central portion of the first heating plate to isolate the temperature sensor from the central portion of the first heating plate; and/or the temperature sensor is arranged on a periphery of the second heating plate, and wherein the second heating plate comprises at least one slit between the temperature sensor and a central portion of the second heating plate to isolate the temperature sensor from the central portion of the second heating plate. In this way, the sensor may not be affected by the heat generated by the heaters or heating plates.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Through the more detailed description of some embodiments of the present disclosure in the accompanying drawings, the above and other objects, features and advantages of the present disclosure will become more apparent, wherein:

Fig. 1 is a block diagram illustrating a hair styling appliance in accordance with embodiments of the present disclosure;

Fig. 2 is a cross-sectional view of a hair straightener in accordance with embodiments of the present disclosure;

Fig. 3 is a perspective view of the hair straightener of Fig. 2;

Figs. 4a and 4b are front and back views of a heating plate in a hair straightener in accordance with embodiments of the present disclosure; and

Fig. 5 is a flowchart illustrating a method of operating a hair styling appliance. Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitations as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones describe below.

As used herein, the term“includes” and its variants are to be read as open terms that mean“includes, but is not limited to.” The term“based on” is to be read as“based at least in part on.” The term“one embodiment” and“an embodiment” are to be read as“at least one embodiment.” The term“another embodiment” is to be read as“at least one other embodiment.” Other definitions, explicit and implicit, may be included below.

Fig. 1 is a block diagram illustrating a hair styling device 10 in accordance with embodiments of the present disclosure. For example, the hair styling appliance may be a hair straightener, a hair curler, a curling wand or a crimping iron.

As shown in Fig. 1, the hair styling device 10 includes a first arm 30 and a second arm 32, which may be coupled to the first arm 30 by a hinge at a respective end of the arms. The arm can also be called a jaw or a clamping member. A first heater 12 may be arranged in the first arm 30 and a second heater 14 may be arranged in the second arm 32. It is to be understood that the first and second heaters 12 and 14 are provided for illustrative purpose only and there may be more or less heaters in the hair styling device 10.

The hair styling device 10 includes a temperature sensor 22 that can sense a hair temperature and output a temperature signal indicative of the sensed hair temperature. The temperature sensor 22 may be arranged on either of the arms 30 and 32. In addition, more than one temperature sensor 22 can be provided in the hair styling device 10.

The hair styling device 10 includes a state sensor 28 that can detect whether the arms 30 and 32 are opened or closed and output a state signal indicative of an open/close state of the arms 30 and 32. The state sensor 28 can be a switch, for example.

The hair styling device 10 includes a controller 24 that receives the temperature signal from the temperature sensor 22 and the state signal from the state sensor 28. If a change in the open/close state of the arms is detected, the controller can identify a current styling operation. The styling operation may also be called a stroke.

In some embodiments, if the arms 30 and 32 are opened, a previous styling operation ends and the current styling operation starts. Then, if the arms 30 and 32 are closed and opened again, the current styling operation ends and a new subsequent styling operation may start.

There may be some alternatives approaches for identifying the strokes based on the open/close state of the arms 30 and 32. For example, in alternative embodiments, if the arms 30 and 32 are closed, a previous styling operation ends and the current styling operation starts. Then, if the arms 30 and 32 are opened and opened again, the current styling operation ends and a new subsequent styling operation may start.

The controller 24 can determine a variation or change in the hair temperature sensed by the temperature sensor 22 from stroke to stroke. For example, the controller 24 can determine the change in the hair temperature from the previous stroke to the current stroke. Then, the controller 24 can determine a count that the hair styling device 10 has operated on a same strand of hair based on the variation in the hair temperature, thereby controlling the hair styling.

In some embodiments, the hair temperature can be an average temperature of hair during the stroke or styling operation. In this way, the variation in the hair temperature is indicated by the change in the average temperature from stroke to stroke. It is to be understood that any other suitable characteristic temperature can be used, for example, a maximum temperature during the stroke.

For example, the controller 24 can increment the count if the variation indicates an increase in temperature from the previous stroke to the current stroke. Otherwise, the controller 24 can reset the count to one. In other words, if the temperature increases from stroke to stroke, the count of strokes increment and the current stroke is applied to the same strand of hair as the previous stroke. If the temperature does not increase from stroke to stroke, the count of strokes resets to one and the current stroke is applied to a new strand of hair.

In some embodiments, if the count exceeds a predetermined threshold, the controller 24 may turn off the heaters 12 and/or 14. In this way, the strand of hair will not be damaged. Additionally or alternatively, the controller 24 may provide a visual and/or audible indication of the count. In this way, the user can learn the actual count of the strokes and the hair condition. Then the user can decide whether to proceed with the same strand of hair.

In a hair styling appliance, the temperature sensor is mounted inside the heating plate, usually next to the heater. During the stabilizing state, the temperature of the actual heating plate outer surface is unknown. The controller uses the heating plate’s internal temperature with an offset temperature to approximate the heating plate surface temperature. This method is prone to variations such as the distance between the sensor and the heating plate, the tolerance of heating element’s power output, the ambient temperature, the material density’s tolerance, and assembly quality, which all could affect the accuracy of the approximation, resulting in the heating plate outer surface not matching the user selected temperature target.

An example hair straightener in accordance with embodiments of the present disclosure will now be described in detail with reference to Figs. 2 and 3. Directional terminology, such as“top”,“bottom”,“front”,“back”,“leading”,“trailing”, etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments described herein can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration only and is in no way limiting.

Figs. 2 and 3 show an example configuration of a hair straightener 10 according to an example embodiment of the present disclosure, in which Fig. 1 shows a cross-sectional view of the hair straightener 10 and Fig. 2 shows a perspective view of the hair straightener 10. It is to be understood that the configuration of the hair straightener 10 can also be applied to any other suitable hair styling devices such as a hair curler.

As shown in Figs. 2 and 3, the hair straightener 10 includes a first arm 30 with a first heating plate 18 on its inner surface. In addition, the hair straightener 10 further includes a second arm 32 that is coupled to the first arm 30 by a hinge 26. In this way, the first and second arms 30 and 32 can be opened and closed to allow styling operation of a hair strand.

The hair straightener 10 can be operated in an open state in which the arms 30 and 32 are opened and a closed state in which the two arms 30 and 32 are closed. In the open state, it is desirable to stabilize the temperature of the outer surface of the heating plate 18 to a target temperature defined by the user. In the closed state, it is desirable to raise the temperature of the hair to the desired styling temperature for the shortest amount of time without causing the hair to overheat. To this end, the temperature of the heating plate 18 can be measured in the open state and the temperature of the hair can be measured in the closed state.

As shown in Figs. 2 and 3, the second arm 32 is provided with a contactless temperature sensor 22. The contactless temperature sensor 22 has a field of view facing the first heating plate 18 and measures the temperature of the object within the field of view. For example, the active surface of the contactless temperature sensor 22 is exposed on the surface of the second arm 32. In the open state, there is no hair between the arms 30 and 32, and the contactless temperature sensor 22 can measure the temperature of the first heating plate 18. In the closed state, a strand of hair is sandwiched between the arms 30 and 32, and the contactless temperature sensor 22 can measure the temperature of the strand of hair. Because the temperature sensor 22 can directly sense the temperature of the surface of the heating plate and the hair strand, the accuracy of temperature measurement can be substantially improved.

In some embodiments, the contactless temperature sensor 22 may be an infrared temperature sensor that includes an optical window for receiving infrared light, the optical window facing the first heating plate 18. Although the contactless temperature sensor 22 is described in connection with an infrared optical sensor herein, it is to be understood that any suitable temperature sensor currently known or to developed in the future may be used, for example, a contactless temperature sensor, an optical sensor, or a thermistor.

For example, the first arm 30 may be provided with a first heater 12 for heating the first heating plate 18, and the first heater 12 may be disposed within the first heating plate 18, for example, around the first heating plate 18 to improve the heating effect. Alternatively, the first heater 12 may also be disposed on a surface of the first heating plate 18. The second arm 32 may be provided with a second heating plate 20 on its inner surface opposite the first heating plate 18. For example, as shown in Figs. 2 and 3, the contactless temperature sensor 22 may be disposed in an aperture in the second heating plate 20. The aperture can also penetrate at least partially through the heater 14. Alternatively, temperature sensor 22 may also be disposed at any other suitable locations of the second arm 32. The second arm 32 may be provided with a second heater 14 for heating the second heating plate 20, and the second heater 14 may be disposed within the second heating plate 20. Alternatively or additionally, a temperature sensor (not shown) may be similarly disposed within the first heating plate 18. The controller 24 can be configured to receive a temperature signal from the contactless temperature sensor 22 and to adjust at least of power and heating time of the first heater 12 and/or the second heater 14 based on the temperature signal. For example, controller 24 may receive a temperature signal from the temperature sensor 22, calculate a suitable heater output, and generate an output signal to control the power and heating time of the heaters 12 and 14. The heat generated by the heaters will affect the temperature of the hair in the closed state, or the surface temperature of the heating plates in the open state. The temperature sensor 22 can periodically perform temperature measurements and controller 24 can generate the control signal based on the periodic temperature measurements. This duty cycle can continue until the hair straightener 10 is turned off.

In the open state, the temperature sensor 22 may measure the temperature of heating plates 18 and/or 20, and controller 24 may adjust the power of first heater 12 and/or second heater 14 based on the measured temperature, so as to control the temperature of the heating plates 18 and/or 20 to a predetermined temperature or a predetermined temperature range. In the closed state, the temperature sensor 22 measures the temperature of the hair, and controller 24 can adjust the power of the first heater 12 and/or second heater 14 to control the temperature of the hair to a predetermined temperature. For example, in each stroke, the temperature sensor 22 measures the hair strand. The controller 24 can use the temperature signal of the temperature sensor 22 to control the output of the heater to raise the hair temperature until the hair temperature reaches a predetermined temperature at which the hair will not be permanently damaged.

In addition, the controller 24 can also control the heating time of the first heater 12 and/or the second heater 14. For example, in the open state, when the measured hair temperature exceeds a predetermined hair temperature limit, the controller 24 can turn off the heaters to prevent thermal damage to the hair. In some embodiments, if determining that the hair temperature will exceed a predetermined hair temperature limit, the controller 24 can turn off the heaters to reduce heat transfer to the hair and prevent thermal damage to the hair. For example, the temperature sensor 22 can periodically measure the temperature signal, and controller 24 can predict the trend of hair temperature based on the temperature signal sensed by temperature sensor 22 to determine if the hair temperature will exceed the predetermined hair temperature limit.

In some embodiments, the state sensor 28 may be implemented by a switch configured to detect whether the first and second arms 30 and 32 are in a closed/open state, and outputting a state signal indicative of an open/close state of the arms 30 and 32. The controller 24 may receive the status signal from state sensor 28 and adjust at least one of the power and heating time of first heater 12 and/or second heater 14 based on the status signal and the temperature signal from the temperature sensor 22. For example, the controller 24 may calculate a suitable heater output based on the status signal and the temperature signal and generate an output signal to control the power of the heaters and / or the like.

Figs. 4a and 4b are front and back views of a heating plate in a hair straightener in accordance with embodiments of the present disclosure. The heating plate can be one or both of the heating plates of a hair straightener or other hair styling device.

As shown in Figs. 4a and 4b, the temperature sensor 22 is arranged on a periphery of the heating plate and the heating plate includes a slit 42 between the temperature sensor 22 and the central portion of the heating plate. In this way, the heat produced by the heater can be isolated from the temperature sensor 22 to avoid thermal damage. The temperature sensor 22 can be a thermistor or contactless temperature sensor such as an infrared temperature sensor.

Fig. 5 is a flowchart illustrating a method 50 of operating a hair styling device in accordance with embodiments of the present disclosure. It is to be understood that the method 500 can be used in the device 10 or any other suitable hair styling device.

At block 52, in response to detecting a change in an open/close state of arms of the device, a current styling operation is identified.

In some embodiments, identifying the current styling operation comprises: in response to detecting that the arms are opened, determining that the previous styling operation ends and the current styling operation starts; and in response to detecting that the arms are subsequently opened, determining that the current styling operation ends.

At block 54, a variation in temperature of hair between the current styling operation and a previous styling operation is determined.

In some embodiments, determining the variation in temperature comprises: determining a first average temperature during the previous styling operation; determining a second average temperature during the current styling operation; and determining a difference between the second average temperature and the first average temperature. At block 56, a count that the device has operated on a same strand of hair is determined based on the variation in temperature of hair, to thereby control the hair styling.

In some embodiments, determining the count comprises: in response to the variation indicating an increase in temperature from the previous styling operation to the current styling operation, incrementing the count; and in response to the variation not indicating an increase in temperature from the previous styling operation to the current styling operation, resetting the count to one.

In some embodiments, the method 50 further comprises in response to the count exceeding a predetermined threshold, turning off a heater of the device; and/or providing at least one of a visual or audible indication of the count.

Although the present disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

I/We Claim:

1. A method (50) of operating a device for hair styling, comprising:

in response to detecting a change in an open/close state of arms of the device, identifying (52) a current styling operation;

determining (54) a variation in temperature of hair between the current styling operation and a previous styling operation; and

determining (56), based on the variation in temperature of hair, a count that the device has operated on a same strand of hair, to thereby control the hair styling.

2. The method (50) of claim 1, wherein identifying (52) the current styling operation comprises:

in response to detecting that the arms are opened, determining that the previous styling operation ends and the current styling operation starts; and

in response to detecting that the arms are subsequently opened, determining that the current styling operation ends.

3. The method (50) of any of the preceding claims, wherein determining (54) the variation in temperature comprises:

determining a first average temperature of hair during the previous styling operation;

determining a second average temperature of hair during the current styling operation; and

determining a difference between the second average temperature and the first average temperature.

4. The method (50) of any of the preceding claims, wherein determining (56) the count comprises:

in response to the variation indicating an increase in temperature from the previous styling operation to the current styling operation, incrementing the count; and

in response to the variation not indicating an increase in temperature from the previous styling operation to the current styling operation, resetting the count to one.

5. The method (50) of any of the preceding claims, further comprising:

in response to the count exceeding a predetermined threshold, turning off at least one heater of the device; and/or

providing at least one of a visual or audible indication of the count.

6. A device (10) for hair styling comprising:

a first arm (30);

a second arm (32) coupled to the first arm (30);

a temperature sensor (22) configured to sense a temperature of hair and output a temperature signal indicative of the sensed temperature of hair;

a state sensor (28) configured to detect whether the first and second arms (30, 32) are opened or closed and output a state signal indicative of an open/close state of the first and second arms (30, 32); and

a controller (24) configured to:

receive the temperature signal from the temperature sensor (22) and the state signal from the state sensor (28);

in response to detecting a change in the open/close state of the first and second arms (30, 32), identify a current styling operation;

determine a variation in the temperature of hair between the current styling operation and a previous styling operation; and

determine, based on the variation in the temperature of hair, a count that the device (10) has operated on a same strand of hair, to thereby control the hair styling.

7. The device (10) of any of the preceding claims, wherein the controller (24) is configured to identify the current styling operation by:

in response to detecting that the first and second arms (30, 32) are opened, determining that the previous styling operation ends and the current styling operation starts; and

in response to detecting that the first and second arms (30, 32) are subsequently opened, determining that the current styling operation ends.

8. The device (10) of any of the preceding claims, wherein the controller (24) is configured to determine the variation in the temperature of hair by:

9. The device (10) of any of the preceding claims, wherein the controller (24) is configured to determine the count by:

10. The device (10) of any of the preceding claims, wherein the controller (24) is further configured to:

in response to the count exceeding a predetermined threshold, turning off at least one heater of the device (10); and/or

providing at least one of a visual or audible indication of the count.

11. The device (10) of any of the preceding claims, further comprising:

a first heating plate (18) disposed on a surface of the first arm (30); and

a second heating plate (20) disposed on a surface of the second arm (32) opposite to the first heating plate (18).

12. The device (10) of any of the preceding claims, wherein the temperature sensor (22) comprises:

a first contactless temperature sensor arranged on the second arm (32) having a field of view facing the first arm (30) and configured to measure a temperature of an object within the field of view; and/or

a second contactless temperature sensor arranged on the first arm (30) having a field of view facing the second arm (32) and configured to measure a temperature of an object within the field of view.

13. The device (10) of claim 12, when dependent from claim 11, wherein the temperature sensor (22) is disposed in an aperture in the second heating plate (20).

14. The device (10) of any of claims 12 or 13, wherein the temperature sensor (22) comprises an infrared temperature sensor with an optical window for receiving infrared light and facing the first arm (30).

15. The device (10) of any of claims 11 to 14, wherein the temperature sensor (22) is arranged on a periphery of the first heating plate (18), and wherein the first heating plate (18) comprises at least one slit (42) between the temperature sensor and a central portion of the first heating plate (18) to isolate the temperature sensor (22) from the central portion of the first heating plate (18); and/or

wherein the temperature sensor (22) is arranged on a periphery of the second heating plate (20), and wherein the second heating plate (20) comprises at least one slit (42) between the temperature sensor and a central portion of the second heating plate (20) to isolate the temperature sensor (22) from the central portion of the second heating plate (18).