Abstract:
An oral care implement comprises a head with a plurality of cleaning elements, and a light source incorporated into or adjacent the head. The light source is incorporated prior to the attachment of the cleaning elements for ease of manufacturing and a cost-effective assembly. The cleaning elements are preferably pre-formed and attached to the head after the incorporation of the light source so that the provision of the light source does not require any post-processing that might impair the integrity of the head or cleaning elements.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 12/093,686, filed May 14, 2008, which is a national stage entry under 35 U.S.C. §371 of International Patent Application No. PCT/US2006/060875, filed 14 Nov. 2006, which claims priority to U.S. Provisional Patent Application No. 60/736,250, filed 14 Nov. 2005, the entireties of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to oral care implements in general, and more particularly to a method of forming a light-emitting toothbrush. 
       BACKGROUND 
       [0003]    Toothbrushes are generally made in a method in which nylon bristled stock is anchored to a plastic toothbrush head via a metal staple. This requires a minimum head thickness of around 5 millimeters in order to reduce the possibility of plastic breakage during the stapling process given the tuft densities of most standard brushes. Furthermore, the toothbrush head and handle is generally molded in one step and it is a solid plastic part. This does not lend itself to placement of a light source in the toothbrush head. 
         [0004]    In another well known process called in-mold tufting (IMT), nylon bristles are gathered and placed in an injection mold. Plastic is then injected around the bristles forming the toothbrush head and handle. The head must be large enough that plastic can flow over and around the “fused balls of nylon” commonly seen in these type of processes. The plastic over the fused balls retains the tuft in the brush during normal use. Once again there are generally no allowances made for insertion of a light source. 
         [0005]    In each of these methods, incorporating a light source requires a post-processing step, such that the head must be made to accommodate a light source or the transmission of light from a source outside of the head. This post-processing requires time and resources, and often increases the cost to an unacceptable level. Or as an alternative, it requires making the head at a greater thickness (allowing for creation of a hollow section) increasing discomfort for the user while decreasing the user&#39;s ease of maneuverability. Accordingly, there is a need, therefore, for a practical, cost-efficient method of forming a light-emitting oral care implement, such as a toothbrush, that has an acceptable thickness and that is comfortable to the user. 
         [0006]    Such need is met using a method of making an oral care implement or toothbrush where, for example, a head plate and handle are molded separately. The head plate is filled with cleaning elements such as nylon and the nylon is melted to an extremely thin “mat”. Afterwards, this relatively thin head plate is ultrasonically welded to the handle. In this method there is an open cavity in the toothbrush head, or the toothbrush head is effectively hollow, allowing the opportunity to place light emitting elements or other items in the toothbrush head that may provide a therapeutic or cosmetic benefit. Included could be alarms or sonic other device that signal proper or improper brushing techniques, proper amount of brushing time, etc. 
       SUMMARY 
       [0007]    An oral care implement, such as a toothbrush, comprises a head, a plurality of cleaning elements defined thereon, and a light source incorporated into or adjacent the head. The light source is incorporated into the implement prior to the incorporation of the cleaning elements for ease of manufacturing and a cost-effective, user-friendly assembly. The cleaning elements are preferably pre-formed and attached to the head after the light source so that the provision of the light source does not require any post-processing that might impair the integrity of the head or cleaning elements or unduly enlarge the bead so that it is uncomfortable to the user. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a schematic view of an oral care implement of the present invention. 
           [0009]      FIGS. 2A through 5B  represent alternative embodiments of an oral care implement of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0010]    The following detailed description is of the best mode or modes of the invention presently contemplated. Such description is not intended to be understood in a limiting sense, but to be an example of the invention presented solely for illustration thereof, and by reference to which in connection with the following description and the accompanying drawings one skilled in the art may be advised of the advantages and construction of the invention. In the various views of the drawings, like reference characters designate like or similar parts. 
         [0011]      FIG. 1  is a schematic view of an oral care implement  100  having a head  120  with a plurality of cleaning elements  130  provided thereon, and a handle  140  extending from the head  120 . While the oral care implement  100  is illustrated as a toothbrush with non-movable cleaning elements (i.e., a so-called “manual” toothbrush), it will be understood that other oral care implements, such as “power” toothbrushes that have movable cleaning elements, flossers, tongue scrapers, or other implements that don&#39;t have cleaning elements, are contemplated. However, for purposes of convenience, the oral care implement  100  will be described as a toothbrush with cleaning elements  130 . Furthermore, while the cleaning elements  130  are shown as conventional bristles or tufts of bristles, it will be understood that cleaning elements of any type (i.e., bristle tuft, bristle wall, elastomeric), material (i.e. nylon, elastomeric), size, cross-section (i.e., circular, rectangular, diamond-shaped) and the like will be contemplated. 
         [0012]    As shown in  FIG. 2A , the head  120  is further provided with a chamber  122  having a floor  124  and a raised wall  126  having a lip  128 . The raised wall  126  forms the side edges of the head  120 , while the opposite side of the floor  124  defines the rear surface  129  of the head  120 . The cleaning elements  130  are generally formed into a unitary structure that is secured to the head  120  by a process known in the art, such as by adhesion, ultrasonic welding, mechanical snap or press fit, and the like. In particular, the cleaning elements  130  are secured to a plate  132  that is seated on the lip  128 . Such plate  132  is populated with separate cleaning elements  136  by traditional stapled tufting, or by so-called anchor-free tufting (AFT), wherein the ends  134  of a plurality of separate cleaning elements  136  are joined or fused together using a process known in the art. Other methods of forming the cleaning elements  130  known, such as in-mold tufting (MIT) could be utilized although this method may be less preferred in certain circumstances due to the probable increased size of the toothbrush head and the extra manufacturing steps involved. In this IMT method, a sandwich plate is made in which cleaning elements are embedded between two plastic faces that are made as thin as possible, with the cleaning elements extending from a front surface of the plate. Allowance could be made to attach a light source to the bottom or rear surface of this sandwich plate. This plate could then be joined to a handle by any known means such as ultrasonic welding, laser welding, adhesive, plastic overmolding, etc. Alternatively, the sandwich plate could be adhered to a pre-made handle in which the light source is mounted to the handle as described herein. The handle would then be designed in a way to provide mounting for the light source. Other manufacturing techniques known or to be developed are contemplated herein. 
         [0013]    Provided in a socket  125  in the floor  124  of the head  120  of the embodiment of  FIG. 2A  is a light source  150  of any frequency or wavelength. Light source  150  is connected to a power source  160  provided in the handle  140  via connections  155  such as electrical wires or the like. Such power source  160  could take any form, such as, but not limited to, a hard-wired connection to a standard household electrical current, or a portable hatter powered source that could be rechargeable, non-rechargeable, replaceable, non-replaceable, alkaline, nickel cadmium, lithium, polymeric, environmentally-friendly, solar etc. as desired. 
         [0014]    Connections  155  are preferably routed through the neck  145  of the toothbrush  100 , which neck  145  is defined by the region adjacent the head  120  between the head  120  and the handle  140 . Passageways for the wiring connections  155  could be provided, for example, in a first molding and then covered with a second molding. The wiring  155  could also be covered with a second injection molded part that fits into the first molded part, could be covered by film, or in any number of other methods that would be obvious to one experienced in plastic goods manufacturing or in consumer goods packaging. A switch  165  may be provided in the handle  140  to activate the power source  160  and power the light source  150  to obtain oral care benefits as described below. Light emitted from the light source  150  is directed to the oral cavity through at least one opening  138  in the plate  132 , which opening  138  defines a light passage between the chamber  122  and outside thereof. Such opening  138  is preferably sealed to prevent invasion of water, bacteria and debris into the chamber  122 . 
         [0015]    The benefit of light emittance within an oral cavity include, but are not limited to, the increased ability of toothpaste active ingredients to penetrate areas of the oral cavity, particularly interproximal spaces, thus increasing the stated benefits of toothpaste in those areas with increased disruption of the plaque matrix. Generally, the light emittance could increase the plaque matrix disruption normally experienced with the act of brushing one&#39;s teeth. Light, with a high enough or specified frequency, can affect bacterial cells thus deleteriously affecting the ability of bacteria to generate within a plaque matrix further adding value towards a measurable, through expired volatiles, whole mouth clean experience. The presence of light might offer additional benefits, therapeutic value, in combination with specially formulated active ingredients or encapsulated active ingredients that the light would specifically actuate or catalyze offering synergistic affects in delivery vehicles as dentifrices or mouth rinses, or medicinal remedies which could offer relief from oral care health conditions, not all inclusive, such as xerostomia, cancerous lesions or abnormalities, sores, or post-operative maladies. In addition to the increased cleaning efficacy of the light, the user might experience sensory benefits such a cooling or heating effects, gingival or soft tissue stimulation or enhanced health, enamel polishing, enhanced desquamation, polishing, additional bacteriological affects on gram negative bacterial reduction, and an overall increased oral cavity cleansing perception. 
         [0016]    Additionally, the present concept could be coupled with existing powered toothbrush motions including vibratory, oscillating, pulsating, revolving, sonic and ultrasonic as well as use in manual toothbrushes. The toothbrush could be designed with a specialized head section to vibrate or move at these specific frequencies to offer the light benefits to a full range of oral cavity regions. The method of action of the brush head should not be limited to vibration, but should be any type of activation that could involve a dentifrice or mouth rinse or oral care conditioning agent and toothbrush in combination where active ingredients are affected by the presence of light. Furthermore, the toothbrush head could also include either longitudinal or latitudinal serrations, splits, gaps, or designed separations throughout the supportive structure, which isolate functional regions of the toothbrush head, with each region capable of emitting light Such separations include, but are not limited to, singular or multiplicative, and can be serpentine, straight lines, hinged, curves, diagonals, bisecting, symmetric or asymmetric, or other geometrically calculated or conceived configurations that allow for independent movement and/or cleaning action, of these isolated regions which upon the frontal surface of these independent action regions express non-shedding and shedding oral cavity tissue cleaning elements such as groupings or plurality of amide or non-amide filaments or elastomeric features or the like. 
         [0017]    In addition, by pre-forming the cleaning elements  130  and assembling them over a pre-positioned light source, the manufacture of the toothbrush becomes more cost-effective and streamlined. Furthermore, the positioning and variation of the light source in the head chamber allows for flexibility in the type of light source, the type of cleaning elements and the manner in which the two are joined. This flexibility is not realized in prior art structures where the head is specifically designed to accommodate a specific light source in a specific location within a specific bristle construction. 
         [0018]    Light source  150  in  FIG. 2A  is shown as a square-shaped light emitting diode (LED) that is seated within a square-shaped socket  125 . As used herein, the term LED is understood to include a variety of classes of LEDs such as, but not limited to, light-emitting organic materials or organic light-emitting polymers diodes (OLEDs), polymer light-emitting diodes (PLEDs), and light-emitting polymers (LEPs) which offer benefits regarding ease of manufacturing through flexible manufacturing techniques and design configurations, malleability, and that are environmental friendly, disposable and recyclable. Light source  150  could also be a surface-mounted device LED, an LED chip, or a non-LED based light source and/or could vary in shape, size and construction depending on the head environment. In the head  220  of the embodiment of  FIG. 2B , a plurality of light sources  250  may be provided in a plurality of sockets  225  for emitting light through a plurality of openings  238  in a cleaning element plate  232 . Alternatively, in the head  320  of the toothbrush of  FIG. 2C , which also includes cleaning elements  337  fixed to the head  320 , a single light source  350  may be provided in a single socket  325  for emitting light through a plurality of openings  338  in a cleaning element plate  332 . In the embodiments of  FIGS. 2A and 2B , the openings  138 ,  238  constitute focused light passages between the separate cleaning elements  136 ,  236 , while in the embodiment of  FIG. 2C , the openings  338  are uniformly interspersed among the separate cleaning elements  336  for a dispersed light passage and transmission. Such focused light passage is particularly evident if the plate  132 ,  232 ,  332  is made from a material that does not transmit light. However, as shown in the embodiment of  FIG. 2D , if the head  420  and/or plate  432  is/are made from a material that transmits light (transparent or translucent for example), then the plate  432  may not require special openings or light passages as the light from the light source  450  could reach the oral cavity from a multitude of directions as shown by arrows  452 . 
         [0019]    In the embodiments discussed above, the light source is connected to a power source in the handle. However, the power source ma reside in other locations, such as the neck or the head. In addition, a control board  170  ( FIG. 1 ) may be provided in the handle, for example, to control the operation of the light source based on the desired benefit. For example, it may be appropriate for certain situations to strobe the light source, or to have the light source emit light at only certain intervals for certain periods of time. In the embodiment of  FIG. 3A , the light source  550  may reside on a control board  570  to form a controlled light assembly  572  that is itself seated in a socket  525  in the head  520 . Such assembly could be non-removable as shown in  FIG. 3A , or removable and replaceable via an access panel  574  ( FIG. 3B ) provided in the rear surface  529  in the head  520 , or via an access slot  576  ( FIG. 3C ) provided along a side edge  578  or along an upper edge  579  of the head  520 . It may be desirable to replace a light source if it burns out or malfunctions, or if a variety of light sources are desired at different times. For example, it may be preferable to use a first light source having a particular wavelength to treat a particular oral health condition, and then a second light source having a different wavelength to treat a different oral health condition, the two light sources being readily swapped or interchanged as desired. 
         [0020]      FIGS. 4A and 4B  illustrate additional embodiments of a toothbrush  600  having a head  620  with cleaning elements  630  situated thereon and a handle  640 . A light source  650  is located at the end  642  of the handle  640  adjacent the head  620 , or in the neck  645  of the toothbrush  600 , which light source  650  emits light into the chamber  622  defined between the floor  624  and head plate  632 . As shown, the head plate  632  fits over the handle neck  645  and the brush assembly could be completed via ultrasonic welding as is currently done in the AFT technology. Alternatively, the head  620  could be removable from the neck  645  via a threaded connection or the like for replacement of the head  620  and/or access to the light source  650 . 
         [0021]    In the embodiments of  FIGS. 4A and 4B , the floor  624  of the chamber  622  is lined with a reflective or refractive membrane  700  which allows light to be directed through the head plate  632  to the oral cavity as desired. This refractive or reflective membrane reorients the direction of light emitted, regardless of wavelength or frequency, and could be of any known material such as metallic, polymeric or a combination of materials. The membrane could be positioned parallel to the head plate  632  as shown, or at an angle thereto (not shown). The light may also be transmitted through the separate cleaning elements  636  anchored to the head plate  632  if such cleaning elements are made from suitable material. For example, if cleaning elements  636  are bristles, such bristles can be comprised of synthetic polyamides (nylons), polybutylene terephthalate, polyethylene terephthalate materials or elastomeric materials. Such bristles may or may not have incorporated within materials that enhance transference or transmittance of emitted light throughout or surrounding bristle material(s). Bristles may also consist of co-extruded materials and have various cross-sectional shapes or diameters for any of the aforementioned yet not all inclusive listing. The head plate  632  could also comprise specified geometric areas or regions  638 , devoid of cleaning elements  636 , to allow for light transference, which areas or regions  638  could also incorporated additional materials specific to enhancement of light transference, reflectance or refraction. For example, the areas or regions  638  could constitute openings that are covered by prisms or the like (not shown) that act in concert with the reflective or refractive properties of the membrane  700 . 
         [0022]      FIGS. 5A and 5B  illustrate the head portion  820  of an additional embodiment of a toothbrush  800  having cleaning elements  830  on one side of the head  820  and a tongue or soft tissue cleaner  900  on the opposite side, with a light source  850  defined in or adjacent the head  820  as illustrated in previous embodiments. The soft tissue cleaner  900  may comprise a variety of configurations, such as a plurality of nubs  910  as described in U.S. application Ser. No. 10/869,922, which is incorporated by reference herein. In addition to, or instead of the transmission of light through the head plate  832 , the soft tissue cleaner  900  may be formed of a light transmissive material, or it may comprise one or more light passages  938  similar in function to the light passages  838  through the head plate  832 . Such passages  938  may be any shape or configuration as desired. Thus, the toothbrush  800  could direct light through two different cleaning element areas or regions on opposite sides of the head  820 . 
         [0023]    The tongue or soft tissue cleaning feature  900  may also incorporate products, such as sensates, medicaments, catalysts, active ingredients incompatible with active ingredients delivered through dentifrices, mouth rinses or oral care conditioning agents, sundry chemicals such as holistic ingredients, which offer sensorial relief for teething conditions and/or soft tissue irritation, antibacterial affects, cooling or tingling affects, fresh breath, tooth stain reduction, plaque or biofilm inhibition or a combination of aforementioned, which could alleviate or offer remedies towards oral cavity conditions for a period less than permanent.