Patent Description:
Personal care devices include lighting elements to provide a form of communication with a user. For example, some toothbrushes including light emitting diodes (LEDs) are configured to internally reflect emitted light along the inside of the device and emit a diffused glow through predefined exposed areas in the outer covering of the device to provide feedback to a user. Other devices include one or more light rings to provide a visual cue.

However, due to cost and space constraints, such systems are limited in the type and/or number of optical sources and optical elements and the LED light cannot be sufficiently distributed by bulk scattering. Accordingly, there is a non-uniformity of light intensity from different angles of view. For example, as the device is rotated along its primary axis, alternating hot and dark spots are visible. The dark spots indicate spaces between the LEDs. Additionally, light tailoring features cannot be easily added.

Typically, additional LEDs, separate optics, vapor deposited reflection layers, or screens and/or masks are employed to facilitate in the distribution of LED light. However, such systems are costly and/or require significant space and tactile access to the screen and/or mask areas for manufacturability. Such typical systems also require specific tooling and manufacturing processes such that the screens or masks cannot be easily changed in manufacturing.

Accordingly, there is a need in the art for systems and methods for providing handheld devices including a minimal number of light sources and optical elements configured to achieve sufficiently distributed light to produce visibly uniform light.

<CIT> discloses a toothbrush having at least two LEDs, at least one of which illuminates the neck and optionally also the head and the ends of the bristles attached to the head.

<CIT> discloses an oral cleaning device configured to provide real-time feedback to a user using a visual indicator of the device.

<CIT> and <CIT> disclose an oral hygiene implement having an indication element.

The present disclosure is directed to inventive systems and methods for altering the transmission of light emitted from one or more light sources within a housing of a handheld device using an optical element enhanced by laser-induced modifications. For example, an optical element can be a light ring and the inside surface of the light ring, facing a light source, may be modified to change the light incident angle of the incoming light rays from the LED. The modified surface causes optical scattering at the incoming surface which can add to a scattering of light generated by bulk material scattering within the optical element. A polymer surface of the optical element can be modified by applying a sufficient amount of thermal energy from a laser to reflow the surface. The modified surface can include one or more dimple-shaped modifications, for example. An array of dimple-shaped laser-induced modifications in close proximity acts as a plurality of tiny convex lenses which facilitate the scattering of incoming LED light rays. By way of another example, the inside surface can be modified to include darkened regions which absorb more light (than non-darkened regions) to partially block light from passing through the optical element. The darkened regions can be formed by laser energy and frequency in combination with one or more suitable polymer additives to generate thermal chemical carbonization, also known as charring. An optical element can be modified to include one or more reflow areas and/or one or more darkened regions to vary the transparency and scattering effect of the optical element.

An advantage of the systems and methods described herein is that the laser-enhanced optical element can solve the problem with non-uniformity concerns with LED light sources within tight space constraints and without costly additional components.

Another advantage of the systems and methods described herein is that light-tailoring laser-induced modifications can be added in very small spaces where conventional assembly solutions are not possible.

Yet another advantage of the systems and methods described herein is that the laser-enhanced optical element provides the flexibility to modify the final output almost immediately, enabling unique light performance in each product manufactured.

Generally in one aspect, a handheld device is provided according to claim <NUM>.

According to an embodiment, the optical element includes a bulk scattering material to produce a bulk material scattering effect of the light when the light passes through the optical element and the plurality of laser-induced modifications provides a surface scattering of the light when the light passes through the optical element.

According to an embodiment, the plurality of laser-induced modifications includes dimple-shaped modifications.

According to an embodiment, the plurality of laser-induced modifications is variably distributed over the inside surface.

According to an embodiment, the plurality of laser-induced modifications includes one or more charred dots.

According to an embodiment, the one or more charred dots block one or more respective portions of light emitted from the at least one light source from being transmitted through the optical element.

According to an embodiment, the one or more charred dots are formed by laser energy in combination with one or more polymer additives.

According to an embodiment, the at least one light source is a light emitting diode.

Generally in another aspect, a handheld device is provided according to claim <NUM>.

According to an embodiment, the plurality of laser-induced modifications comprises ribs configured to direct light away from a LED hot spot vector of the at least one light source.

According to an embodiment, the plurality of laser-induced modifications comprises circular lines centered at a LED hot spot vector of the at least one light source.

As used herein for purposes of the present disclosure, the term "controller" is used generally to describe various apparatus relating to the operation of a personal handheld device, system, or method. A controller can be implemented in numerous ways (e.g., such as with dedicated hardware) to perform various functions discussed herein. A "processor" is one example of a controller which employs one or more microprocessors that may be programmed using software (e.g., microcode) to perform various functions discussed herein. A controller may be implemented with or without employing a processor, and also may be implemented as a combination of dedicated hardware to perform some functions and a processor (e.g., one or more programmed microprocessors and associated circuitry) to perform other functions.

In various implementations, a processor or controller may be associated with one or more storage media (generically referred to herein as "memory," e.g., volatile and non-volatile computer memory). In some implementations, the storage media may be encoded with one or more programs that, when executed on one or more processors and/or controllers, perform at least some of the functions discussed herein. Various storage media may be fixed within a processor or controller or may be transportable, such that the one or more programs stored thereon can be loaded into a processor or controller so as to implement various aspects of the present disclosure discussed herein. The terms "program" or "computer program" are used herein in a generic sense to refer to any type of computer code (e.g., software or microcode) that can be employed to program one or more processors or controllers.

The term "light source" should be understood to refer to any one or more of a variety of radiation sources, including, but not limited to, LED-based sources (including one or more LEDs as defined above), incandescent sources (e.g., filament lamps, halogen lamps), fluorescent sources, phosphorescent sources, high-intensity discharge sources (e.g., sodium vapor, mercury vapor, and metal halide lamps), lasers, and other types of electroluminescent sources.

As used herein for purposes of the present disclosure, the term "LED" should be understood to include any electroluminescent diode or other type of carrier injection/junction-based system that is capable of generating radiation in response to an electric signal. Thus, the term LED includes, but is not limited to, various semiconductor-based structures that emit light in response to current, light emitting polymers, organic light emitting diodes (OLEDs), laser diodes, electroluminescent strips, and the like. It should also be understood that the term LED does not limit the physical and/or electrical package type of an LED.

The present disclosure is directed to various embodiments of systems and methods for producing visibly uniform light from a minimal number of light sources and optical elements within a handheld device using a laser-enhanced optical element. Applicant has recognized and appreciated that it would be beneficial to provide an effective lighting system for handheld devices using a minimal number of light sources and optical elements by modifying the transparency and scattering effects of the surfaces of the optical elements (rather than focusing on material scattering properties, reflective surface design, and/or light pipe solutions). Accordingly, the systems and methods described or otherwise envisioned herein provide a handheld device configured to provide light emitted from LEDs and a laser-enhanced optical element. The enhancement of the surface of the optical element modifies the transmission of light emitted from one or more light sources by providing scattering effects and/or redirecting effects. Additionally or alternatively, the enhancement of the surface of the optical element modifies the transmission of light emitted from one or more light sources by masking or blocking light from passing through the optical element.

The embodiments and implementations disclosed or otherwise envisioned herein can be utilized with any handheld personal care device. A particular non-limiting goal of utilization of the embodiments and implementations herein is to provide brushing information/indications to a user of a power toothbrush, e.g., a Philips Sonicare™ toothbrush (manufactured by Koninklijke Philips, N. Such information can, for example, be related to error or alert messages (e.g., battery due to be changed/charged, change brush head), instruction or indications related to proper use of the power toothbrush, timer, sensory result messages (e.g., fully cleaned teeth, partially cleaned teeth, good brushing behavior, poor brushing behavior, plaque formation). According to other embodiments and implementations, pertinent information/indications can be provided to users of any power medical, dental, shaving, grooming, mother and child care devices (handheld and non-handheld), for example, which can incorporate the configurations and functionalities described herein (as should be appreciated by a person of ordinary skill in the art in conjunction with a review of this disclosure).

Referring to <FIG>, in one embodiment, a handheld device <NUM> is provided. The handheld device <NUM> includes a body portion <NUM> and a neck portion <NUM> removably or non-removably mounted to the body portion <NUM>. The neck portion <NUM> includes a head member <NUM>. The body portion <NUM> includes a housing, at least a portion of which is hollow, to contain components of the handheld device, for example, a drive assembly/circuit <NUM>, a control unit <NUM>, and a power source <NUM> (e.g., battery or power cord) for producing a brush head motion suitable for effective cleaning of teeth. The movement can be any of a variety of different movements, including vibrations or rotation, among others. The illustrative elements are shown representationally because they are conventional in the art of power toothbrushes. The operation of the toothbrush itself is controlled by an on/off switch <NUM>. The particular configuration and arrangement shown in <FIG> is by way of example only and does not limit the scope of the embodiments disclosed below.

The handheld device <NUM> can include one or more sensors <NUM> configured to obtain sensor data and located on or within the device. Sensor <NUM> is shown in <FIG> near the top of the body portion/handle <NUM>, but may be located anywhere on the device, including, for example, within the neck portion <NUM> or head member <NUM>, to sense brushing information. Processor <NUM> is preferably located within the device and configured to receive sensor data from the one or more sensors <NUM> and process the sensor data obtained from sensor <NUM>. The handheld device <NUM> can include one or more light emitting diodes and a laser-enhanced optical element forming an illumination system <NUM> which may be located on and/or within the device. In <FIG>, the illumination system <NUM> is located at the bottom of the body portion <NUM> of the handheld device <NUM>. In other embodiments, the illumination system <NUM> can be located on and/or within the switch <NUM> or at any other position. The illumination system <NUM> can be responsive to a processor and configured to communicate information/indications to the user. In some embodiments, a storage system/memory <NUM> for storing brushing information may be included for further analysis of information.

<FIG> depicts a schematic representation of an exemplary control system <NUM> of an example handheld device. The control system <NUM> includes a controller <NUM>, a sensor <NUM>, a power source <NUM>, and an illumination system <NUM>. Power source <NUM> may be the same as power source <NUM> for the handheld device <NUM>, or can be a separate power source. Sensor <NUM> can be any sensor programmed and/or configured to obtain sensor data regarding one or more aspects of the user's mouth during a brushing session. For example, the sensor may obtain information/data about the teeth surface, plaque levels, brushing areas, brushing strength, brushing angle, overall brushing effectiveness, and/or a wide variety of other aspects of dental health as described elsewhere herein. The sensor data may also relate to the operating status (on/off condition, normal condition, abnormal condition, battery life, and speed of the motor) of the power toothbrush and other related data. The illumination system <NUM> can be programmed and/or configured to direct light emitted from one or more LED light sources within a hollow portion of the housing of the handheld device through an optical element, for example, a light ring, to provide uniform lighting or any pattern or image on the exterior surface of the illumination system <NUM> to be visible from a user's perspective. In an example embodiment, four LEDs are included however, additional or fewer LEDs are also contemplated.

Controller <NUM> is programmed and/or configured to analyze information/data, transmit/receive information, data and/or commands (control signals) from/to each of the other respective components of the system or external components/devices as may be appropriate to carry out the functions and methods described herein (as should be appreciated and understood by those of skill in the art in conjunction with a review of this disclosure).

The controller <NUM> includes processor <NUM>, memory <NUM>, clock <NUM>, wireless communicator <NUM>, and sensor <NUM>. Processor <NUM> may be the same as processor <NUM>, or can be a separate processor. The controller <NUM> can determine, using sensor data received in real-time or periodically, the information about how the user is brushing his/her teeth. The sensor data can be processed by processor <NUM>. Processor <NUM> can pull pre-programmed levels from memory <NUM> and compare that to the obtained sensor data to determine whether the user is brushing his/her teeth with too much pressure. Clock <NUM> may be utilized by controller <NUM> in order to determine the brushing time, duration, and date, and may be utilized by controller <NUM> in order to recall the appropriate standards from memory <NUM>. Processor <NUM> can further determine, based on stored information, what response may be necessary for excessive pressure, and can pull from memory <NUM> the appropriate illumination to provide to the user. For example, if the pressure is too high, the controller <NUM> can be programmed and/or configured to effectuate the selective illumination of light of a certain color, for example, orange (to indicate to the user that too much pressure is being applied) through illumination system <NUM>. The control system <NUM> may also include a wireless communicator <NUM> for transmitting sensor data to a wireless transceiver (not shown). Sensor <NUM> may also be included in the control system <NUM> to detect motion using any variety of different motion-detecting sensors, and can send a signal to the processor <NUM> that the user has picked up the toothbrush and that an appropriate illumination can be provided as may be appropriate during a brushing event (although, information about the power toothbrush <NUM> itself (such as charging status) can be sensed by either sensor <NUM> or <NUM> and indicated through illumination means <NUM> at any time).

<FIG> is a perspective view of an example optical element <NUM> of an illumination system <NUM> of a handheld device <NUM>. The optical element <NUM> of <FIG> is embodied as a light ring including an inside surface A, an outside surface B opposite the inside surface, a top surface C, and a bottom surface D opposite the top surface. The inside and outside surfaces A, B are circumferential surfaces circumscribing an axis of rotation of the light ring, whereas the top and bottom surfaces C, D are radial surfaces running in parallel planes arranged orthogonal to the axis of rotation of the light ring. Although a ring is depicted here, it should be appreciated that the optical element <NUM> can be embodied as any shape. In the example of <FIG>, the surfaces are planar, however they can also be curved. Further, it should be appreciated that, in the embodiments described or otherwise envisioned herein, at least one light source is arranged within the inside surface A of the optical element <NUM> such that the inside surface A faces the at least one light source and the at least one light source emits light substantially in a first direction toward the inside surface A of the optical element <NUM>. The terms "optical element" and "light ring" are used interchangeably herein.

As shown in <FIG>, inside surface A of the optical element <NUM> may be modified to change the light incident angle of incoming light rays from one or more LEDs. Due to the modified configuration of the surface, optical scattering can occur at inside surface A to redirect LED light rays. In addition to the optical scattering that can occur at the inside surface A, the light can be further distributed, or scattered, as the light passes through the bulk material of the optical element <NUM>. In example embodiments including an optical element formed of a polymer at least partially, the surface configuration of the inside surface A can be modified by using laser marking.

Laser marking refers to computerized methods of applying marks, including bar codes, logos, or other information to surfaces of products using a laser beam rather than inks or tool bits. Laser marks are created by a variety of processes, some involving removing material from the surface, for example, by vaporization, others involving a thermal-chemical surface reaction mechanism, for example, by melting. One such surface reaction mechanism is thermal-chemical carbonization, or charring. In plastics, a laser and a corresponding appropriate additive can cause thermal degradation in a polymer resulting in the formation of a black or dark marking for light colored plastics (or a white or light marking for dark colored plastics). Laser marking by charring produces darkened regions which absorb more light than un-darkened regions.

Referring back to <FIG>, inside surface A can be modified using laser marking by transforming radiation energy into thermal energy in the polymer surface. The thermal energy can be sufficient to cause reflow of the polymer surface embodied as dimple-shaped laser-induced modifications, for example. An array of dimple-shaped laser-induced modifications in close proximity can act as many tiny convex lenses which facilitate to scatter the incoming LED light rays. Laser-induced modifications including reflow lenses (or dimple-shaped laser-induced modifications) are shown on inside surface A in <FIG>.

<FIG> shows a schematic sectional representation of the inside surface A of <FIG>, taken generally along line <NUM>-<NUM> in <FIG>, including a single reflow lens <NUM> (or dimple-shaped modification). The left side of the inside surface A depicts unmarked polymer surface, whereas the right side of the inside surface A (including the single reflow lens <NUM>) depicts modified polymer surface. The incoming LED rays <NUM> emitted by at least one LED become scattered rays <NUM> due to the single reflow lens <NUM>. It should be appreciated that air surrounds the single reflow lens <NUM> between the LED emitting the LED rays <NUM> and the inside surface A.

In <FIG>, the top surface C is modified (instead of inside surface A) to include a plurality of laser-induced modifications including reflow ribs <NUM>. The reflow ribs <NUM> are configured to direct light away from a LED hot spot vector of the light source. The reflow ribs <NUM> act as waveguides to re-pipe the light away from the LED hot spot vector. <FIG> is a schematic sectional representation of the section of <FIG>, taken generally along line A-A in <FIG>.

<FIG> is a perspective view of an example optical element <NUM> including a pattern of laser-induced modifications embodied as a mask <NUM> formed on the inside surface A. <FIG> is an enlarged schematic representation of the encircled section of the optical element in <FIG>. In example embodiments including an optical element formed of a polymer at least partially, a transparency of the inside surface A can be modified by laser energy and frequency in combination with one or more special polymer additives to produce thermal chemical carbonization, also known as charring. Charring the polymer causes a darkening of the surface which absorbs more light than uncharred areas. One pattern of laser-induced modifications, for example, a plurality of carbonization markings, or charred dots, is shown on the inside surface A of <FIG>. The shape of each marking or dot can be circular or any other suitable shape. The laser-induced modifications in <FIG> includes an area having an increased density of darkened spots to reduce light transmittance of a LED hot spot vector <NUM>. In embodiments, the increased density of the markings can decrease as a distance along the inside surface A increases relative to the LED hot spot vector <NUM>. In other words, the markings can be tailored to be distributed as the inverse of the LED intensity sphere. For example, the larger the incoming light intensity, the smaller the spacing to block more transmission of the incoming light. Similarly, the smaller the incoming light intensity, the larger the spacing to allow more transmission of the incoming light. In other words, laser-induced modifications can be configured to gradually mask high intensity light regions while allowing lower intensity regions to pass through to the bulk material. This gradient mask produces a uniform output intensity distribution.

<FIG> shows an alternate embodiment of laser-induced modifications including darkened lines <NUM> with variable spacing. In example embodiments, inside surface A can also be modified to create a diffraction grate corresponding to the darkened lines <NUM>. <FIG> shows an alternate embodiment of laser-induced modifications including spots <NUM> having a variable density to distribute a scattering effect corresponding to a LED hot spot. <FIG> shows an alternate embodiment of laser-induced modifications including a circular diffraction grate <NUM> to provide scattering at a LED hot spot and more vertically where more LED intensity is needed.

In <FIG>, in addition to including a plurality of laser-induced modifications on the inside surface A, a plurality of laser-induced modifications is also included on the top surface C. In example embodiments, the top surface C includes circular laser-marked lines <NUM> centered at a LED hot spot vector <NUM>. The re-scattering of the laser lines may redirect LED rays toward dark quadrants in a light ring (assuming four LEDs are included) and away from a LED hot spot. In <FIG>, a reflective coating is applied to the entireties of the top and bottom surfaces C, D to facilitate light travelling through the optical element to dark quadrants in a light ring. Laser marking technologies can be used to burn away portions of the reflective coating applied to the top surface C and/or the bottom surface D. As shown in <FIG>, laser lines that have burned away the reflective coating <NUM> allow bleeding off of light from a LED hot spot.

The laser-induced modifications described herein can be implemented with any suitable laser marking technology. The term "laser-induced modification" refers to any transformation created at a surface, or within the space, of an optical element, including any two dimensional and/or three dimensional transformation, which is caused by an interaction involving laser energy and the optical element (or some coating or finish applied to the surface of the optical element). One example transformation caused by laser marking is the formation of reflow lenses in the surface due to a shrinking of polymer particles when heated. Another example transformation caused by laser marking is the formation of darkened areas in the surface due to a thermal chemical carbonization whereby light energy is absorbed in the substrate and raises the local temperature of the material surrounding the absorption site high enough to cause thermal degradation of the polymer. Alternatively, the texture of the surfaces of the optical element can be modified by laser ablation or any other suitable process. Additionally, one or more lasers can be used with a clear optic to add laser-induced modifications to the internal space of an optical element or interface. In a further example, two lasers can be used with clear optics to provide three dimensional laser-induced modifications to an internal space of an optical element or interface by additive interference where the lasers cross paths to create sufficient energy to cause a material property reaction. <FIG> shows an example embodiment of an optical element including three dimensional laser-induced modifications <NUM> inside the optical element.

Advantageously, the inventive systems and methods (disclosed as examples) described herein provide an optical element for producing a combination distribution effect including bulk material scattering and surface scattering (obviating the need to include costly vapor deposited reflection layers or other additional cost components). The surface scattering effect produced by the laser-enhanced optical element sufficiently distributes light circumferentially such that hot spots and dark spots produced by LEDs are not visible. Point light sources associated with conventional light rings in handheld devices exhibit hot spots and dark spots because the light cannot be sufficiently distributed within the limited physical boundaries of the light ring bulk material. Although the embodiments described herein aid in providing light homogeneity circumferentially about a light ring, it should be appreciated that other circumferential light distributions that are not necessarily uniform yet distributed to provide a specific pattern or image or logo are also contemplated.

Although laser marking is typically used to change the light reflection of a surface of a product for the purpose of mark recognition, the laser-induced modifications described herein, while they can be produced using laser marking, are not used to change the light reflection of the surface for mark recognition. Instead, the laser-induced modifications are configured to control light transmission through the bulk material of the optical element. The laser-induced modifications are formed on an inside surface rather than the exterior surface.

Typical manufacturing processes for producing screens or masks for optical elements require significant space and tactile access to the screen/mask areas. Such typical systems also require specific tooling and manufacturing processes such that the screens or masks cannot be easily changed in manufacturing. The light tailoring of laser-induced modifications described herein can be added in small spaces, where conventional assembly solutions are not possible. Additionally, the systems and methods described herein enable a manufacturer to modify the final output almost immediately, as in inline manufacturing, such that the light performance in each product manufactured can be unique if desired. For example, an optical element can be modified to account for varying manufacturing tolerances. Additionally, handheld devices can be customized to include a user's name, for example, by applying an appropriate arrangement to an optical element such that the user's name can be visible by illuminating the marked optical element (rather than marking the exterior surface for mark recognition).

In example embodiments, laser-induced modifications can be applied to a separate piece of plastic and adhered to the inside surface and/or the top surface of the optical element. In other example embodiments, laser-induced modifications can be applied directly to the inside surface and/or the top surface of the optical element.

All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in the herein cited documents, and/or ordinary meanings of the defined terms.

In general, the term "or" as used herein shall only be interpreted as indicating exclusive alternatives (i.e. "one or the other but not both") when preceded by terms of exclusivity, such as "either," "one "only one of," or "exactly one of.

While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, the scope being determined by the appended claims.

Claim 1:
A handheld personal care device (<NUM>), comprising:
a housing;
at least one light source arranged within the housing, the at least one light source configured to emit light in at least a first direction;
an optical element (<NUM>) comprising an inside surface (A) facing the at least one light source and an outside surface (B) opposite the inside surface, the optical element configured to transmit light from the light source; and
a plurality of laser-induced modifications (<NUM>) formed on the inside surface (A) or inside the optical element and configured to alter a transmission of light through the optical element; wherein the plurality of laser-induced modifications is configured to provide a uniform distribution of light on the outside of the optical element.