Handheld personal care device with light system

Abstract

A handheld personal care device (1) with an optical system comprises an operating unit (3) connected to a main housing (2), a light source (24) and an optically transparent light guide (23) having a light receiving surface (27), a light emitting surface (6) and a light guide member (31) extending from the light receiving surface to the light emitting surface, for guiding light from the light receiving surface to the light emitting surface. The light source is arranged in a watertight chamber (51) of the main housing. The main housing comprises an optically transparent wall portion (52) arranged adjacent to the light source and defining the watertight chamber. The light guide is arranged outside the watertight chamber, and the light receiving surface is arranged adjacent to the optically transparent wall portion in a position for receiving light from the light source via the optically transparent wall portion.

Description

Technical Field

[0001] The present invention relates to a handheld personal care device with a light system. Background Art

[0002] JP2016-185214A discloses a shaving device with a light guide, which forms a sealed closure of a window opening in a recess bottom plate, in which an outer cutter member and an inner cutter member are housed. Inside the light guide, a light source is provided. In operation, light from the light source passes through the light guide and is emitted through an opening in a plate located inside the outer cutter member and the inner cutter member, and shines on and through these cutter members. The light creates an illusion of atmosphere and activates a photocatalyst, which decomposes organic matter to prevent odor emission. The light leaking through the outer cutter member illuminates the skin and thereby promotes shaving.

[0003] From JP2018-196484A, a shaving device is known, in which a light-transmitting cover plate has a light guide protruding through a window opening in the plate at the bottom of a recess in which an outer cutter member and an inner cutter member are accommodated. Inside the light guide, a light source is arranged. In operation, light from the light source passes through the opening in the plate via the light guide and is emitted inwardly from the outer cutter member and the inner cutter member and impinges on and through these cutter members. The light promotes shaving and stimulates the bactericidal action of the photocatalyst. In addition, the luminous state of the light source can indicate the charge state of the battery. Summary of the invention

[0004] An object of the present invention is to provide a handheld personal care device in which the light of a light system arranged in the device is more easily and continuously visible during use, while achieving a low-cost but reliable shielding of the light source of the light system from liquids and dust.

[0005] According to the present invention, this object is achieved by providing a handheld personal care device according to the present invention.

[0006] Because the main housing includes an optically transparent wall portion arranged adjacent to the light source and defining a watertight chamber, and because the light guide is arranged outside the watertight chamber and the light receiving surface is arranged adjacent to the optically transparent wall portion and at a position where light from the light source is received via the optically transparent wall portion, the light source is very reliably shielded from liquid and dust. Because the light guide does not extend into the watertight chamber, it is not necessary to provide an opening in the watertight chamber (via which the light guide can extend into the watertight chamber), and therefore it is not necessary to provide a sealing member along the light guide at such an opening position for shielding the watertight chamber and the light source arranged therein. In addition, because the light guide can guide the light generated by the light source and leaving the watertight chamber via the optically transparent wall portion along a certain distance to a position where the light is to be emitted or made visible to a user, a high degree of design freedom is achieved with respect to the position of the light source, the watertight chamber and the optically transparent wall portion, so that the light can be more easily visible at any desired position, especially on the outer surface of the main housing. Specifically, the position of the light source can be relatively far away from the position where the light is to be emitted or made visible, and the emitted light can be visible from a direction different from the direction from which the light source emits the light or the direction in which the outer surface of the optically transparent wall portion faces.

[0007] The specific embodiments, features of the present invention and effects thereof are set forth in the description and are apparent from the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a perspective view of an example of an apparatus according to the present invention;

[0009] Figure 2 is based on Figure 1 A cross-sectional view of the top of the main housing of the device;

[0010] Figure 3 is based on Figure 1 and Figure 2 A perspective view of a light guide, a shaving unit bracket and a housing shield of the device;

[0011] Figure 4 is based on Figures 1 to 3 A front view of a light guide, housing shield and printed circuit board of a device;

[0012] Figure 5 is based on Figures 1 to 4 Side view of the light guide, housing shield and printed circuit board of the device. Specific embodiments

[0013] In the accompanying drawings, an example of a handheld personal care device 1 according to the present invention is shown, which has a main housing 2 arranged to be held by a hand and an operating unit 3 for performing personal care operations on a body part of a user. In this example, the personal care device is an electric shaving device, and its operating unit is a shaving unit 3. However, the personal care device can also be a device with an operating unit for other personal care operations, such as a depilatory head, a hot air outflow opening (for example, for hair drying), a heated hair clamp (for example, for hair curling or hair straightening), or a temperature sensor (for measuring body temperature). The operating unit can be mainly arranged on the outside of the main housing (for example, in this example), or partially, mainly or completely arranged on the inside of the main housing (for example, the operating head, surface or opening is flush with the adjacent part of the main housing).

[0014] In this example, if Figure 2 and Figure 3 As shown, the motor 7 is arranged in the main housing 2, and the drive gear 8 is mounted on the motor output drive shaft 9 protruding from the motor 7. The drive gear 8 engages with the driven gear 9 fixed to the central drive shaft 10. The central drive shaft 10 is rotatably suspended in the main housing 2. The drive coupling 11 is coupled to the free end of the central drive shaft 10 and is arranged for driving engagement with the driven coupling (not shown) of the shaving unit 3. The shaving unit 3 is detachably connected to the shaving unit bracket 12. The shaving unit bracket 12 is suspended relative to the shield 13 via a pair of leaf springs 14, 15 on opposite sides of the shaving unit bracket 12 and connected to the bracket beam 16 of the shaving unit bracket 12. The shield 13 is fixed between the housing 21 and the housing 22 of the main housing 2. The ends of the leaf springs 14, 15 opposite to the ends mounted on the bracket beam 16 are coupled to the base 17 located on the respective mutually opposite sides of the shaving unit bracket 12. The base 17 is fixed relative to the shield 13 .

[0015] A magnet 18 is mounted to the underside of the shaving unit bracket 12. Immediately below the shield 13, a printed circuit board (PCB) 19 is mounted in the main housing 2, carrying a Hall sensor 20 close to and aligned with the magnet 18. The Hall sensor 20 is connected to a circuit 5, which is also mounted to the PCB 19. Light sources 24, 25, 26 are also mounted to the PCB 19 and are also arranged in the main housing 2. The circuit 5 is arranged to output a voltage for activating or deactivating the light sources 24 to 26 in response to a measured distance between the magnet 18 and the Hall sensor 20, which is representative of the shaving pressure applied to the shaving unit 3. If an excessive shaving pressure causes the shaving unit 3 to press the shaving unit bracket 12 toward the shield 13 further than when the shaving pressure would be within a preferred range or below a given threshold, the light sources 24 to 26 are activated. In response to such a too small measured distance between the magnet 18 and the Hall sensor 20, the circuit may cause, for example, a green light source to be deactivated and, for example, a red light source to be activated. Intermediate distances are also conceivable, in which, for example, an orange or yellow light source is activated and the other light sources are deactivated. It is also possible to use an RGB LED, so that the light sources can each be controlled to emit light of a specific color, for example blue for too low a shaving pressure, green for a shaving pressure within a suitable range, and red for too high a shaving pressure.

[0016] The indication of the applied shaving pressure takes place by a light system 4 housed in the main housing 2 of the device 1, of which the light sources 24 to 26 are part. The light system 4 is thus connected to be activated as a function of the applied shaving pressure and forms an indicator of the applied shaving pressure.

[0017] The light system 4 may alternatively or additionally be connected to circuitry for monitoring other operating conditions of the device, such as sensing circuitry for indicating the progress of a shaving operation, circuitry for indicating the battery charge status, or circuitry for indicating whether cleaning or replacement of (components of) the shaving unit is recommended.

[0018] The light system 4 has, near the shaving unit 3 , a light emitting surface 6 which extends circumferentially around the main housing 2 as a closed loop surface around a main axis 36 of the extension of the main housing 2 .

[0019] Because the light emitting surface 6 constitutes a closed loop surface extending circumferentially around the main axis 36 extending around the main housing 2, the light generated by the light system 4 can be seen from almost all sides of the device 1, so the light system 4 will generally remain visible (directly or via a reflector for visual monitoring of the operation applied) regardless of the orientation maintained by the device 1. In particular, when the light system 4 is used to indicate rapidly changing conditions (such as shaving pressure, resistance encountered, drive torque applied, rotational speed or temperature of exhaust air), it is particularly advantageous if the indication of the condition changing out of or into a preferred range is immediately noticed so that the user can take immediate action to restore the condition to the preferred range.

[0020] The light emitting surface may also have a shape different from a closed loop and, for example, be located only on one side of the main axis of the extension, or take the form of a plurality of light emitting surfaces distributed around the main axis of the extension. In addition, the light may be used for other purposes than indicating the operating condition of the device, such as for illuminating the skin surface to be treated or for purely decorative purposes.

[0021] In order to provide a particularly good visibility of the light emitting surface 6 of the light system 4 during use, it is advantageous if the light emitting surface 6 extends circumferentially around a first housing part to which the shaving unit 3 is connected. The first housing part is therefore an upper part of the main housing 2 situated between the shaving unit 3 and a second housing part of the main housing 2 remote from the shaving unit 3. Preferably, the axial length of the first housing part along the main axis 36 of extension is less than or equal to 50% of the total axial length of the main housing 2 along the main axis 36 of extension, and more preferably less than or equal to 33% of this total axial length, and more preferably 20% of this total axial length. Thus, the light emitting surface 6 of the light system 4 is preferably arranged in an upper part of the main housing 2 close to the shaving unit 3, which is usually the part of the device 1 that is most visible to the user during use, and leaves plenty of space for holding the main housing 2 by hand without obscuring the light system 4 from view.

[0022] When the device 1 is in an operating condition, the drive system formed by the central drive shaft 10 and the drive coupling member 11 coupled to the shaving unit 3 extends through the closed-loop luminous surface 6. Therefore, if the shaving device 1 is rotated with the shaving unit 3 remaining protruding from the main housing 2 in substantially the same direction, the luminous surface 6 of the optical system 4 remains visible, as typically occurs during shaving. Furthermore, during use of the device for performing other personal care operations, the operating unit typically remains oriented in substantially the same direction as the device is manipulated during use, while movements and rotations in a plane generally perpendicular to this direction typically have a greater amplitude. Regardless of such movement, the closed-loop luminous surface of the optical system 4 remains visible.

[0023] like Figure 2As shown, the space available in the handheld personal care device is very small, which makes it difficult to realize the light emitting surface 6, such as forming a closed loop surface circumferentially around the main housing 2 without adding a significant amount of volume to the main housing 2. In addition, the brightness of the light emitting surface 6 should preferably be substantially constant over the entire circumference, and the number of light sources should be limited in view of cost constraints. In order to meet these requirements, the optical system 4 also includes an optically transparent light guide 23. The light emitting surface 6 is a closed loop surface of the light guide 23, which faces a direction having a main component in an outward radial direction relative to the extended main axis 36. In this example, the light emitting surface 6 includes: a central portion 37, which is oriented obliquely relative to the extended main axis 36, and the closed loop light emitting surface 6 extends around the central portion; an outer portion 38, which faces mainly radially outward relative to the extended main axis 36; and an inner portion 39, which faces mainly axially relative to the extended main axis 36. All of these parts form a closed loop surface extending around the extended main axis 36. The light guide 23 also has a light receiving surface including light receiving surface portions 27, 28 and 29 arranged at an average axial position relative to the main axis 36 of extension, which is further away from the shaving unit 3 than the average axial position of the light emitting surface 6. The light receiving surface portions face in a direction having a main component in the axial direction away from the shaving unit 3 relative to the main axis 36 of extension. The light sources 24 to 26 are each located adjacent to a corresponding one of the light receiving surface portions 27 to 29 in the axial direction, so that light generated by the light sources 24 to 26 during operation is received by the light receiving surface portions 27 to 29. The light guide 23 has a light guide member in the form of a light guide wall 31 extending from the light receiving surface portions 27 to 29 of the light receiving surface to the light emitting surface 6. The light guide wall 31 is formed integrally with the rest of the light guide 23, but may also be a different member. A portion of the light guide wall 31 including the closed loop light emitting surface 6 of the light guide 23 extends around the main axis 36 of extension as a closed loop wall portion 40. The light guide wall 31 is curved and gradually expands from an orientation having a principal component parallel to the principal axis 36 of extension at the light receiving surface portions 27 to 29 of the light receiving surface to an orientation having a principal component perpendicular to the principal axis 36 of extension at the light emitting surface 6 .

[0024] Thus, the light sources 24 to 26 are positioned spaced apart from the light emitting surface 6, which leaves space in the spatial region around which the closed-loop wall portion 40 of the light guiding wall 31 extends for components providing the personal care functionality of the device (in this example, in particular the shaving unit bracket 12 with the suspensions 14 to 17 and the coupler 11). Furthermore, the curved light guiding wall 31 guides the light at the light receiving surface portions 27 to 29 from a main axial propagation direction relative to the main axis 36 of extension towards a more radially outward propagation direction at the light emitting surface 6 relative to the main axis 36 of extension. The curved light guiding wall 31 also spreads the light over a considerable distance in the circumferential direction, thereby achieving a very uniform illumination of the light emitting surface 6. Since the plurality of light sources 24 to 26 are arranged in evenly distributed positions adjacent to the light receiving surface portions 27 to 29 of the light receiving surface in the axial direction, the uniformity of the illumination of the light emitting surface 6 is further enhanced.

[0025] In order to distribute the light evenly along the light emitting surface 6 while leaving space for components of the device 1 providing personal care functions, it is also advantageous that the light guide wall 31 of the light guide 23 is a cylindrical wall. According to the cylindrical shape of said light guide wall 31, the light emitting surface 6 extends along a first circumferential edge portion 41 of the cylindrical wall on the side of the cylindrical wall facing the shaving unit 3, and the light receiving surface portions 27 to 29 of the light receiving surface extend along a second circumferential edge portion 42 of the cylindrical wall on the side of the cylindrical wall 31 facing away from the shaving unit 3.

[0026] By manufacturing the first circumferential edge portion 41 of the light guide wall 31 including the light emitting surface 6 from an optically diffuse material, the uniformity of the illumination of the light emitting surface 6 is further enhanced. The optically diffuse material diffuses the light entering the first circumferential edge portion 41, thereby achieving a more uniform distribution of light along the circumference of the light emitting surface 6. The rest of the light guide wall 31 may be made of an optically transparent material having a relatively high optical transparency to optimize the light guiding properties of the light guide wall 31. The light guide wall 31 may be made of the two different materials by a 2K injection molding process.

[0027] In some embodiments, a single light source can be sufficient to achieve the desired uniformity of illumination intensity in the circumferential direction along the light emitting surface, provided that the single light source is sufficiently far away from the light emitting surface to achieve the desired uniformity of the circumferential distribution of light in the light guide with an appropriate design of the light guide. However, for uniform illumination intensity in the circumferential direction along the light emitting surface, it is advantageous to provide multiple light sources, especially if there is little space available for the light guide wall 31 in the direction of the extended main axis 36. Then, the light sources 24 to 26 are preferably arranged adjacent to the light receiving surface in the axial direction and distributed along the light receiving surface.

[0028] In order to accommodate components that provide a personal care function of the device (shaving in this example), and in particular to allow a portion of these components to extend from a position inside the light guide 23 to a position outside the light guide 23, the light guide wall 31 of the light guide 23 has recesses 32, 33 and 35. The recess 34 is provided to further improve the uniformity of the intensity of the emitted light in the circumferential direction of the light emitting surface 6. The respective recesses 32, 33, 34, 35 form an interruption of the light receiving surface at a position between the light sources 24 to 26, respectively, and thus divide the light receiving surface into light receiving surface portions 27 to 29. The recesses 32 to 35 each extend from the light receiving surface in a direction toward the light emitting surface 6.

[0029] As best seen with reference to the recesses 33 and 34, the recesses 32 to 35 have two opposing side walls 43 to 49, respectively, which gradually converge from the light receiving surface in the direction towards the light emitting surface 6. This is advantageous for a uniform distribution of light in the circumferential direction towards the light emitting surface 6, especially if, as in the present example, the recesses 32 to 35 and the light sources 24 to 26 are positioned and shaped so that each portion of the light receiving surface 6 is (also) directly illuminated by light from at least one of the light sources 24 to 26 guided by the light guiding wall 31.

[0030] The light sources 24 to 26 are arranged in the watertight chamber 51 of the main housing 2, while the light guide 23 is arranged outside the watertight chamber 51 and is separated from the light sources 24 to 26 and the watertight chamber 51 by the shield 13 forming a sealing member of the watertight chamber 51. The shield 13 has an optically transparent wall portion 52 and a sealing portion 53, which is in sealing contact with an adjacent portion of the main housing 2, which further defines the watertight chamber 51. Therefore, although the light guide 23 is arranged outside the watertight chamber 51 and is not protected from dust and moisture from the environment of the device 1, the light sources 24 to 26 are hermetically shielded from the environment and are thereby protected from dust and moisture from the environment by the shield 13. The sealing portion 53 is a circumferential portion of the shield 13 surrounding the optically transparent wall portion 52, so that the seam between the circumference of the shield 13 and the adjacent portion of the main housing 2 is hermetically sealed.

[0031] The optically transparent wall portion 52 is made of an optically transparent first material, and the sealing portion 53 of the shield 13 (which surrounds the optically transparent wall portion 52) is made of a second material. The second material is more flexible than the first material, but does not need to be optically transparent. Because the flexible second material is in sealing contact with the adjacent components of the main housing 2 that define the watertight chamber 51, the watertight chamber 51 is reliably sealed by a single component, which helps to assemble and handle the components during the manufacture of the device 1. The first material can be, for example, polymethyl methacrylate (PMMA) or polycarbonate (PC), and the second material can be, for example, a thermoplastic elastomer (TPE). For reliable sealing function, while providing sufficient support function for the shield 13, the hardness of the second material is preferably 40 to 80 Shore A (ASTM D2240-15e1), and more preferably 50 to 70 Shore A (ASTM D2240-15e1) and / or the Young's modulus is higher than 1.7 MPa, more preferably higher than 2.4 MPa, and lower than 5.5 MPa, more preferably lower than 2.8 MPa.

[0032] The optically transparent wall portion 52 and the sealing portion 53 of the shield 13 are integrally formed by an injection molding process in which a first material is molded to a second material, or vice versa. Thus, a particularly reliable connection between the first and second materials is obtained in a simple and effective manner.

[0033] During use, the light generated by the light sources 24 to 26 is transmitted to the light receiving surface portions 27 to 29 of the light guide 23 via the optically transparent wall portion 52. To this end, the optically transparent wall portion 52 is arranged adjacent to the light sources 24 to 26 and delimits a watertight chamber 51, the light guide 23 is arranged outside the watertight chamber 51, and the light receiving surface portions 27 to 29 are arranged adjacent to the optically transparent wall portion 52 in a position for receiving light from the light sources 24 to 26 via the optically transparent wall portion 52. Therefore, the light sources 24 to 26 are very reliably shielded from dust and liquid from the environment of the device 1. Furthermore, since the light from the light sources 24 to 26 is transmitted to the light guide 23 via the optically transparent wall portion 52 of the shield 13, the light guide 23 does not need to extend into the watertight chamber 51 via an opening of the watertight chamber 51, in particular via an opening in the shield 13. Therefore, at such a position of the opening for shielding the light sources 24 to 26, no additional sealing element along the light guide 23 is required. Furthermore, because the light guide 23 can guide light along the distance from the optically transparent wall portion 52 to the position where the light is to be emitted or made visible to the user (the closed-loop light emitting surface 6 in this example), a high degree of design freedom is achieved regarding the positions of the light sources 24 to 26, the optically transparent wall portion 52, and the watertight chamber 51. The light sources 24 to 26 can be located relatively far from the position where the light is to be emitted or made visible to the user (the closed-loop light emitting surface 6 in this example), and the light can be visible from a direction different from the direction in which the light sources 24 to 26 emit the light and the direction in which the outer surface of the optically transparent wall portion 52 faces.

[0034] Since the chamber 51 is watertightly sealed, the light sources 24 to 26 are very reliably shielded from water and other liquids as well as shaving debris. The optically transparent wall portion 52 may be optically completely transparent, but may also have one or more rough (e.g. "frosted") surface portions and / or contain white and / or colored reflective particles for dispersing, scattering and / or coloring the transmitted light.

[0035] Although in other embodiments, there may be a small air gap between the light receiving surface portions 27 to 29 and the optically transparent wall portion 52, in the embodiment shown in the drawings, the light guide 23 is arranged so that the light receiving surface portions 27 to 29 are in direct contact with the optically transparent wall portion 52 of the shield 13. This prevents shaving debris and other liquids and dust from entering between the light receiving surface portions 27 to 29 of the light guide 23 and the optically transparent wall portion 52 of the shield 13. Therefore, the light path is reliably kept open without the need for the light guide 23 to actually extend directly up to the front of the light sources 24 to 26. In addition, the direct contact between the light receiving surface portions 27 to 29 and the optically transparent wall portion 52 of the shield 13 improves the light coupling efficiency between the light sources 24 to 26 and the light guide 23.

[0036] In an alternative embodiment of the device 1, debris and other dust can be prevented from intruding into the light path, and a particularly high light transmission efficiency can be achieved, wherein the light guide 23 is integrally formed with the optically transparent wall portion 52, for example, by an injection molding process. Thus, the light guide 23 can be integrally formed with the shield 13 including the optically transparent wall portion 52 and the shielding portion 53.

[0037] Although in the embodiment shown in the drawings, the light-guiding member of the optical system is a cylindrical light-guiding wall 31, it will be clear to those skilled in the art that the light-guiding member can be configured in any suitable shape, any suitable size and any suitable number, especially depending on the shape, size and number of the light-emitting surfaces, through which the light needs to be visible to the user. In a specific example, a plurality of light sources are arranged in a watertight chamber, and the light of each light source is transmitted to a corresponding one of a plurality of light-emitting surfaces arranged in different positions on the outer surface of the main housing via a cylindrical or tubular optically transparent light-guiding member. Such a plurality of cylindrical or tubular light-guiding members can be formed integrally with the transparent wall portion and the shielding portion, in particular by an injection molding process. However, for a light-guiding member having a shape different from that of a cylindrical or tubular light-guiding member, it is also possible to form the transparent wall portion and the light-guiding member integrally.

[0038] If the light guide is not in direct contact with the optically transparent wall portion, it is beneficial for the light coupling efficiency if the distance between the light receiving surface of the light guide and the optically transparent wall portion is small, for example less than 1 mm, less than 0.3 mm and most preferably less than 0.05 mm.

[0039] Although the present invention has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description should be considered illustrative or exemplary rather than restrictive; the present invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention by studying the drawings, the disclosure, and the appended claims.

[0040] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single element or other unit may fulfill the functions of several items recited in the claims. 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.

[0041] Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A handheld personal care device (1), comprising: - a main housing (2) arranged to be held by hand; - an operating unit (3) connected to the main housing and adapted to perform personal care operations on a user's body part; - an optical system (4) housed in the main housing and comprising a light source (24, 25, 26) and an optically transparent light guide (23) having a light receiving surface, a light emitting surface (6) and a light guide member (31) extending from the light receiving surface to the light emitting surface for guiding light from the light receiving surface to the light emitting surface; wherein the light source is arranged in a watertight chamber (51) of the main housing; wherein the main housing comprises an optically transparent wall portion (52) arranged adjacent to the light source and defining the watertight chamber; as well as Wherein the light guide is arranged outside the watertight chamber, the light receiving surface is arranged adjacent to the optically transparent wall portion at a position for receiving light from the light source via the optically transparent wall portion.

2. The device (1) according to claim 1, wherein the light guide (23) is arranged such that the light receiving surface is in direct contact with the optically transparent wall portion (52).

3. The device (1) according to claim 1, wherein the light guide (23) is formed integrally with the optically transparent wall portion (52) by an injection molding process.

4. The device (1) according to any one of claims 1 to 3, wherein the optically transparent wall portion (52) is part of a sealing member (13), which is in sealing contact with an adjacent portion of the main housing (2) further defining the watertight chamber (51).

5. A device (1) according to claim 4, wherein the optically transparent wall portion (52) is made of a first optically transparent material, wherein the sealing member (13) further comprises a sealing portion (53), wherein the sealing portion (53) surrounds the optically transparent wall portion and is made of a second material that is more flexible than the first optically transparent material, and wherein the sealing portion (53) is in sealing contact with the adjacent portion of the main shell (2).

6. The device (1) according to claim 5, wherein the optically transparent wall portion (52) and the sealing portion (53) of the sealing member (13) are integrally formed by an injection molding process, in which the first optically transparent material is molded to the second material, or vice versa.

7. The device (1) according to any of the preceding claims, wherein the light source (24, 25, 26), the optically transparent wall portion (52) and the light guide (23) constitute a light system for indicating an operating condition of the personal care device (1).

8. A device (1) according to any one of the preceding claims, wherein the main housing (2) has an extended main axis (36), and wherein the light emitting surface (6) extends circumferentially around the main housing as a closed loop surface around the extended main axis.

9. A device (1) according to claim 8, wherein the main housing (2) has a total axial length along the main axis (36) of the extension, and comprises a first housing portion and a second housing portion, the operating unit (3) being connected to the first housing portion, the second housing portion being arranged away from the operating unit, wherein the light emitting surface (6) extends circumferentially around the first housing portion, and wherein the axial length of the first housing portion along the main axis of the extension is ≤ 50% of the total axial length.

10. The device (1) according to claim 8 or 9, wherein: - the light emitting surface (6) is a closed loop surface of the light guide (23), the light guide (23) facing in a direction having a main component in an outward radial direction relative to the main axis (36) of extension; - the light receiving surface is arranged at an average axial position farther from the operating unit (3) than the average axial position of the light emitting surface with respect to the main axis of the extension, and faces a direction having a main component away from the operating unit in the axial direction with respect to the main axis of the extension; - a light source (24, 25, 26) is arranged in a position adjacent to the light receiving surface in the axial direction; - the light guide member of the light guide is a light guide wall (31), wherein at least a part of the light guide wall including the closed loop surface of the light guide extends around the main axis of the extension as a closed loop wall portion (40); as well as - Viewed in a cross section along a plane including the main axis of the extension, the light guide wall is curved and gradually expands outward from an orientation having a main component parallel to the main axis of the extension at the light receiving surface to an orientation having a main component perpendicular to the main axis of the extension at the light emitting surface.

11. The device (1) according to claim 10, comprising a plurality of light sources (24, 25, 26) arranged in distributed positions adjacent to the light receiving surface of the light guide (23) along the axial direction.

12. A device (1) according to claim 10 or 11, wherein the light guiding wall (31) has at least one recess (32, 33, 34, 35) extending from the light receiving surface in a direction toward the light emitting surface (6), the recess (32, 33, 34, 35) forming an interruption of the light receiving surface, the interruption dividing the light receiving surface into at least two light receiving surface portions (27, 28, 29).

13. The device (1) according to claim 12, wherein the recess (32, 33, 34, 35) has two opposite side walls (43, 44, 45, 46, 47, 48, 49), which gradually converge from the light receiving surface in the direction towards the light emitting surface (6).

14. The device (1) according to claim 12 or 13 comprises at least two light sources (24, 25, 26), wherein each light source is arranged in a position adjacent to a corresponding one of the at least two light receiving surface portions (27, 28, 29) along the axial direction.

15. The device (1) according to claim 9, wherein the axial length of the first housing portion along the main axis of extension is ≤ 33% of the total axial length.

16. The device (1) according to any one of the preceding claims, wherein the device (1) is an electric shaving device, and wherein the operating unit (3) is a shaving unit.

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