Skin treatment device

Abstract

The present application relates to a skin treatment device having a handle portion arranged to be held in a hand of a human user, a treatment head portion having a skin treatment unit and a skin contact frame having a skin contact surface, the skin contact frame at least partially surrounding a skin treatment area, and a vibration generation unit coupled with the skin contact frame to vibrate at least a portion of the skin contact frame at an ultrasonic frequency.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a skin treatment device having a treatment head portion comprising a skin treatment unit and a skin contact frame intended for contacting skin in operation, and in particular to such a skin treatment device intended for being moved while the skin contact frame is in contact with the skin. BACKGROUND

[0002] Known are skin treatment devices such as light based skin treatment devices, wherein the skin contact frame has to be in close contact with the skin when skin treatment is implemented, e.g. treatment light is applied, in order to avoid strong light to escape, as such strong light can be harmful for the eyes of the user. Such devices can comprise a skin contact sensor that positively confirms that the skin contact frame is in close contact with the skin. In order to apply treatment light to other parts of the skin, the skin treatment device can be separated from the skin and brought in close contact with the skin at another part. It can be considered more convenient by the user to move the skin treatment device over the skin, i.e. to keep the skin contact close between the skin contact frame and the skin while moving the device. In order to support the movement of the skin contact frame over the skin, a material can be chosen that has a low coefficient of friction with the skin, or a lubricant can be applied to the skin to reduce the friction between the skin and the skin contact frame.

[0003] It is an object of the present invention to improve known skin treatment devices, and in particular the ease of use of such skin treatment devices. SUMMARY

[0004] According to one aspect, there is provided a skin treatment device having a handle portion arranged to be held in a hand of a human user, a treatment head portion having a skin treatment unit and a skin contact frame having a skin contact surface, the skin contact frame at least partially encircling a skin treatment area, and a vibration generation unit coupled with the skin contact frame to vibrate at least a part of the skin contact frame at an ultrasonic frequency. BRIEF DESCRIPTION OF DRAWINGS

[0005] The present disclosure will be further clarified by the following detailed description of exemplary embodiments, with reference to the accompanying drawings. In the drawings,

[0006] Figure 1 is a schematic view of an exemplary skin treatment device; and

[0007] Figure 2 is a schematic view of an exemplary skin treatment device applied on the skin of a user, wherein components of the skin treatment device are shown. DETAILED DESCRIPTION

[0008] According to the present application, a skin treatment device is proposed, the skin treatment device having a handle portion and a treatment head portion, wherein the treatment head portion comprises a skin treatment unit and a skin contact frame. In some embodiments, the treatment head portion is repeatedly attachable to and detachable from the handle portion. Additionally or alternatively, in some embodiments, the skin contact frame is repeatedly attachable to and detachable from the treatment head portion. The skin contact frame has a skin contact surface for close contact with the skin to be treated. The skin contact frame can completely surround the skin treatment area, or the skin contact frame can comprise one or several skin contact frame elements that only partially surround the skin treatment area, for example the skin contact frame can comprise oppositely positioned bar elements. The skin contact frame can also cover the skin treatment area, for example the skin contact frame can comprise or consist of skin contact frame elements that are transparent for the treatment light applied by the skin treatment device onto the skin. This means that in some embodiments, the skin contact frame extends over the skin treatment area and can comprise a window for the treatment light. While the skin treatment unit can comprise one or several skin treatment elements such as one or several razor blades that can come into contact with the skin to perform the skin treatment, the skin contact surface of the skin contact frame can additionally be only a part of the skin treatment device that is intended to contact the skin to be treated during regular operation of the skin treatment device. This shall not exclude, of course, that the handle portion can typically be in contact with the skin of at least one hand of the user during operation.

[0009] The skin treatment device can be implemented as one of the following: a light-based hair removal device, a light-based skin treatment device, a manual razor, a power razor, an epilator, a skin cleansing device, a skin massage device, or a skin exfoliation device, which shall be understood as a non-limiting list of possible skin treatment devices. The skin treatment unit can comprise at least one of the following: a light source for applying treatment light, one or several razor blades, an epilator roller, a razor head, a trimmer, a massage head, an exfoliation head, or a brush.

[0010] The skin contact frame can be a floating mounting portion of the skin treatment device that allows the skin contact frame to vibrate relative to the rest of the skin treatment device, e.g. the skin contact frame can be mounted at a mounting portion of the skin treatment device by means of at least one resilient element. The at least one resilient element can be a spring such as a coil spring, a leaf spring, or an elastic element such as a man-made or natural rubber element. In some embodiments, the skin contact frame comprises at least one portion that is driven into vibration, rather than the entire skin contact frame being driven into vibration. The skin contact frame can comprise two or more portions that are driven into vibration, such as three or four or five portions, etc. Different portions can be driven into different types of vibration, e.g. different portions can vibrate at different frequencies and / or amplitudes, or the vibrations can have different directions. Different portions can be coupled with different vibration generation elements of the vibration generation unit. In some embodiments as described above, where the skin contact frame is removable, the vibration generation unit is capable of being removed together with the skin contact frame.

[0011] It is generally known that two objects sliding with their opposite surfaces on each other can experience a so-called stick-slip phenomenon (also known as slip-stick or simply stick-slip), in which a spontaneous jerky motion occurs instead of continuous sliding. It is believed that this phenomenon of alternating between the two surfaces sticking to each other and sliding on each other can be explained by dividing the friction between the two surfaces into static and kinetic friction. While the coefficient of static friction can generally be larger than the coefficient of kinetic friction, the applied force can overcome the static friction and the total friction reduces to the kinetic friction can cause a sudden increase in the speed of motion between the two objects. Rubbing a glass harp with wet fingers along the rim of a thin-walled wine glass or the like is an example of stick-slip phenomenon.

[0012] According to the present invention, it is suggested that at least a portion of the skin contact frame is coupled with a vibration generation unit to cause high frequency vibrations of at least the portion of the skin contact frame or the entire skin contact frame, in particular micro-vibrations with an amplitude of between 0.1 pm and 5 pm. The vibrations of the portion of the skin contact frame or the entire skin contact frame should be such that the skin surface, due to its inertia, cannot follow the vibrations of the portion of the skin contact frame or the entire skin contact frame, thereby causing the friction between the two surfaces, i.e. the skin surface and the skin contact surface of at least the portion of the skin contact frame or the entire skin contact frame, to be essentially always governed by the coefficient of kinetic friction. It can be sufficient to vibrate only a portion of the skin contact frame, e.g. a portion representing about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the skin contact surface of the skin contact frame, to achieve the mentioned effect of the complete skin contact frame, i.e. the complete skin contact surface of the skin contact frame.

[0013] The vibration can at least have a linear reciprocating component and / or an oscillating rotational component. The vibration should have a vector component parallel to the contact surface between the skin contact frame and the skin, which component can in particular be at least about 50% or at least about 60%, 70%, 80%, 80%, 90%, 95% or technically as close as possible to about 100% of the total vibration. In the case of oscillating rotation or eccentric oscillating rotation, the axis of rotation can have an angle of at least about 45 degrees or at least about 50 degrees, 60 degrees, 70 degrees, 80 degrees, 85 degrees or about 90 degrees with respect to the skin. Of course, the angle with respect to the skin is given by the angle with respect to the plane or slightly curved surface defined by the skin contact surface of the skin contact frame.

[0014] The vibration generation unit can be implemented by a piezoelectric actuator, in particular by a piezoceramic actuator, wherein the piezoceramic material can be rigidly connected to at least a portion of the skin contact frame or to the entire skin contact frame, respectively, depending on what is to be vibrated. In the case of several skin contact frame elements forming the skin contact frame independently together, each of the skin contact frame elements can be coupled, in particular rigidly coupled, with an associated vibration generation element, for example a piezoceramic actuator, wherein the vibration generation elements together serve the vibration generation unit.

[0015] While the static friction between the skin contact surface of the skin contact frame and the skin surface is effectively reduced by the vibration of at least one portion of the skin contact frame, this should not exclude that also other means of reducing the friction between the two surfaces are employed, such as a macroscopic structure or a microscopic texture of the skin contact surface of the skin contact frame or a lubricant applied to the skin and / or the skin contact surface of the skin contact frame. In the latter case, the skin treatment device can be arranged to apply a lubricant to the skin. To achieve this, the skin contact frame can comprise at least one lubricant dispensing hole through which a lubricant can be applied to the skin.

[0016] The vibration generating unit can be arranged to generate vibrations with a frequency between 20 kHz and 1 MHz (i.e. a frequency in the ultrasound range), in particular a frequency between 20 kHz and 100 kHz, such as about 30 kHz, 40 kHz, 50 kHz, 60 kHz, 70 kHz, 80 kHz, 90 kHz or any other frequency within a given range. The amplitude of the vibrations of the skin contact frame can be between 0.1 pm and 5.0 pm (i.e. vibrations that can be characterized as micro-vibrations), in particular between 0.2 pm and 2.0 pm, such as about 0.3 pm, 0.4 pm, 0.5 pm, 0.6 pm, 0.7 pm, 0.8 pm, 0.9 pm, 1.0 pm, 1.1 pm, 1.2 pm, 1.3 pm, 1.4 pm, 1.5 pm, 1.6 pm, 1.7 pm, 1.8 pm or 1.9 pm or any other value within a given range. It was found that the amplitude A of the vibrations required for effectively reducing the stick-slip of the skin contact frame with the skin is inversely proportional to the frequency f, i.e. A ~ 1 / f. For example, an amplitude of 0.1 pm can be applied for a high frequency such as 1 MHz, and an amplitude of 5.0 pm can be applied for a low frequency such as 20 kHz. For a frequency of 30 kHz, an amplitude of 1.0 pm can be applied.

[0017] The skin treatment device can comprise a control unit for controlling at least one or more aspects of the skin treatment device, as will be further discussed below.

[0018] In some embodiments, the skin treatment device comprises at least one user operable input element or interface element, such as a button, a switch, a touch panel or a touch sensitive display, to at least control the switching on or off of at least one of the vibration generating unit and / or the amplitude or frequency of the vibrations caused by the vibration generating unit. While the user is generally interested in switching on or off the vibration generating unit, the switching off of the vibrations of the skin contact frame can in particular result in a "sticking" of the skin contact frame on the skin (due to a sudden increase of the static friction coefficient), and from which such sticking can support the user in keeping the skin contact frame positioned at a selected point for applying a skin treatment, e.g. applying a treatment light for skin beautification, acne treatment or temporary or permanent hair removal. The mentioned user operable input element can be coupled with the control unit.

[0019] In some embodiments, the control unit is arranged to control at least one of the switching on or off of the vibration generation unit based on at least one of a skin treatment parameter and / or an amplitude or frequency of the vibrations generated by the vibration generation unit. The skin treatment parameter can be a treatment time, i.e. a duration of the treatment from a start time point until a current time point, a force applied on the skin contact frame, or a movement or speed or velocity of the skin treatment device, in particular of the skin contact frame relative to the skin. Thereby, the skin treatment device can comprise a clock function, a force sensor for measuring the force applied on the skin contact frame, and / or a movement sensor to determine the movement of the skin treatment device, in particular of the skin contact frame relative to the skin. In case of a force sensor, the force sensor can be implemented by a capacitive force sensor. In case of a movement sensor, the movement sensor can be implemented by at least one inertial sensor, e.g. an accelerometer, a gyroscope and / or a magnetometer, and / or an optical sensor as commonly known from optical computer mice.

[0020] Since the static friction between two surfaces tends to increase by a force pushing one of the surfaces onto the other surface, the control unit can be arranged to change at least one of the amplitude or frequency depending on the force applied on the skin contact frame, e.g. to adapt the anti-slip effect to the value of the applied force. Assuming that the user wants to perform the skin treatment at the current point, the control unit can further be arranged to switch off the vibration generation unit when the force applied on the skin contact frame increases above a threshold value. Once the vibrations are switched off, the “sticking effect” as described above occurs and allows to apply the treatment at the current point.

[0021] If the skin contact frame moves a certain distance between a previous treatment position and a current position, the control unit can be arranged to switch off the vibration generation unit. The control unit can then further be arranged to switch on a skin treatment element of the skin treatment unit to provide a skin treatment at the current point, e.g. the skin treatment element can be a light source for applying a treatment light. Generally, the control unit can be arranged to synchronize the operation of the vibration generation unit and the skin treatment element.

[0022] Figure 1 is a schematic view of an exemplary skin treatment device 1 implemented as a light-based skin treatment device for emitting a treatment light from a skin treatment unit 40 comprising a skin treatment element 41 implemented as a flash light. The skin treatment device 1 comprises a treatment head portion 10 and a handle portion 20. The treatment head portion 20 comprises a skin contact frame 30 having a skin contact surface 301 and the skin contact frame 30 here completely surrounds a skin treatment area 302 implemented as a light outlet through which light from the skin treatment element 41 can be applied onto the skin of a user in the shown embodiment.

[0023] As Figure 1 The skin contact frame 30 as shown in Fig. 1 comprises two parts 310 and 311, wherein part 310 has a skin contact surface 3101 forming a part of the entire skin contact surface 301 of the skin contact frame, and part 311 has a corresponding skin contact surface 3111. In at least one mode, the complete skin contact frame 30 comprising parts 310 and 311 can be driven to vibrate by the vibration generation unit, and in at least one other mode, only one or both of parts 310 and 311 are driven to vibrate. In at least one mode, the skin contact frame is driven to vibrate in a different way compared to part 310 or parts 310 and 311. Figure 1 Embodiments of the application are understood not to be limiting.

[0024] The skin treatment device 1 here comprises a first user operable input element 21 which can be implemented as an on / off button for the entire device, and a second user operable input element 22 which can be implemented as an on / off button for the vibration generation unit. A third user operable input element 23 can be implemented as a slider for changing the frequency of the vibrations caused by the vibration generation unit.

[0025] Figure 2 is a schematic view of an exemplary skin treatment device 1A and several components thereof. The skin treatment device 1A comprises a treatment head portion 10A and a handle portion 20A having a handle housing 21A which can be arranged such that it can be conveniently grasped by a user’s hand. The skin treatment device 1A comprises a skin contact frame 30A which is here shown to be in contact with a skin surface 90A to be treated during operation of the skin treatment device 1A, the skin contact frame 30A being coupled with a vibration generation unit 31A. The skin treatment device 1A further comprises a skin treatment unit 40A comprising a skin treatment element 41A and a skin treatment unit housing 42A, the skin treatment device further comprising a control unit 50A coupled with various user operable input elements 51A, 52A, sensors 53A, 55A and an indication element 54A.

[0026] In the illustrated example, the skin contact frame 30A is mounted floating at the mounting structure 11A of the treatment head portion 10A by means of the elastic element 32A. The skin contact frame 30A encircles a skin treatment area 302A through which skin treatment can be effected - here application of treatment light emitted by the skin treatment element 41A. The vibration generation unit 31A can be realized as a piezoelectric ceramic actuator. Operation of the vibration generation unit 31A is controlled by the control unit 50A. As indicated by the double arrow V, the vibration generation unit 31A can here cause the entire skin contact frame 30A to vibrate substantially parallel to the skin contact surface 301A of the skin contact frame 30A. The vibration can be characterized by a frequency f and an amplitude A. This is not to be understood as limiting, as the vibration generation unit 31A can instead cause the vibration to have a non-deterministic variation of frequency and amplitude within a certain range. The skin treatment device 1A here comprises a first user operable input element 51A to switch the skin treatment device 1A on and off. The skin treatment device 1A here further comprises a second user operable input element 52A by which the user can be enabled to change the frequency f and / or the amplitude A of the vibration caused by the vibration generation unit 31A, or to optimize the effect of reducing stiction and / or to customize the operation according to user preferences. In some embodiments, a change in one of the frequency f or the amplitude A can result in a change of the other one of the frequency f or the amplitude A in inverse proportion.

[0027] The skin treatment device 1A here comprises a force sensor 53A for measuring the force F with which the skin contact frame 30A pushes against the skin surface 90A. The user can apply a force F above a threshold value, thereby effecting the control unit 50A to switch off the vibration generation unit 31A so that stiction between the skin contact surface 301A of the skin contact frame 30A and the skin surface 90A causes the skin contact frame 30A to stick or glue to the skin. Then, as the user cannot easily move the skin treatment device 1A further on the skin, the skin treatment is performed at the point chosen by the user. Additionally and / or alternatively, the control unit 50A can be arranged to automatically stop the vibration generation unit 31A, e.g. when the motion sensor 55A has determined that the skin treatment area 49A is moved on the skin to a skin area adjacent to a previously treated skin area. At least one indication element 54A can be arranged on the handle portion housing 21A to indicate information to the user, e.g. that skin treatment is currently being performed.

[0028] The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm."

Claims

1. Skin treatment device, comprising: - a handle portion arranged to be held in a hand of a human user; - a treatment head portion having a skin treatment unit and a skin contact frame with a skin contact surface, the skin contact frame at least partially surrounding a skin treatment area; and - a vibration generation unit coupled with the skin contact frame to cause at least a portion of the skin contact frame to vibrate at an ultrasonic frequency substantially parallel to the skin contact surface, thereby effectively reducing stick-slip or static friction of the skin contact frame; wherein the vibration generation unit is controlled to vary an amplitude and a frequency of the vibration inversely proportional to each other; the skin treatment device comprising a control unit arranged to vary at least one of the amplitude and the frequency depending on a force exerted on the skin contact frame.

2. Skin treatment device according to claim 1, wherein the vibration generation unit comprises a piezoelectric actuator.

3. Skin treatment device according to claim 1 or 2, wherein the vibration of the skin contact frame caused by the vibration generation unit comprises at least a linear reciprocating vibration component.

4. Skin treatment device according to claim 1 or 2, wherein the vibration of the skin contact frame caused by the vibration generation unit comprises at least an oscillatory rotational component about a rotational axis.

5. Skin treatment device according to claim 1, wherein the frequency of the vibration is between 20 kHz and 1 MHz.

6. Skin treatment device according to claim 5, wherein the amplitude of the vibration is between 0.1 pm and 5.0 pm.

7. Skin treatment device according to claim 1, wherein the skin treatment device comprises at least one user operable input element for controlling at least one of the amplitude or the frequency of the vibration.

8. Skin treatment device according to claim 1 or 2, wherein the skin treatment device comprises a sensor for determining a force acting on the skin contact frame.

9. Skin treatment device according to claim 1 or 2, wherein the control unit is arranged to control the vibration generation unit based on a skin treatment parameter.

10. Skin treatment device according to claim 9, wherein the skin treatment parameter is a treatment time or a movement of the skin contact frame relative to the skin or a force acting on the skin contact frame.

11. Skin treatment device according to claim 1, wherein the control unit is arranged to synchronize the control of the vibration generation unit with a control of the skin treatment unit in case the skin treatment unit is switched on when the vibration generation unit is switched off.

12. Skin treatment device according to claim 1 or 2, wherein the skin treatment device comprises at least one user operable input element for controlling at least one aspect of the vibration generation unit. ​ 13. The skin treatment device of claim 1 or 2, wherein the skin treatment device comprises at least one sensor for determining a motion of the skin treatment device.

14. The skin treatment device of claim 1 or 2, wherein the skin treatment device is one of a light-based hair removal device, a light-based skin treatment device, a manual razor, a power razor, an epilator, a skin cleansing device, a skin massage device, or a skin exfoliation device.

15. The skin treatment device of claim 2, wherein the piezoelectric actuator is a piezoceramic actuator.

16. The skin treatment device of claim 5, wherein the frequency of the vibration is between 20 kHz and 100 kHz.

17. The skin treatment device of claim 6, wherein the amplitude of the vibration is between 0.2 pm and 2.0 pm.

18. The skin treatment device of claim 12, wherein the user-operable input element is for turning the vibration generation unit on and off.

Images