CROSS REFERENCES TO RELATED APPLICATIONS
FIELD OF THE INVENTION
This application is related to and claims benefit of U.S. Provisional Patent Application No. 60/872,761 filed on Dec. 4, 2006 and entitled “TOOTH BRUSH WITH BLUE LIGHT SOURCE” and such teaching and disclosure is hereby incorporated by reference.
- BACKGROUND OF THE INVENTION
The present invention relates to dental hygiene and, in particular, to a toothbrush which emits radiation, in the near ultraviolet region of the electromagnetic spectrum, in order to oxidize and destroy potentially harmful bacteria and/or other contaminants or compounds contained within the mouth and also activate a photo catalyst that may be deposited on the teeth and the gums of the person utilizing the toothbrush during normal brushing.
The use of photocatalysis in dental hygiene processes is well established and stems from processes for purifying gases and liquids and for controlling bacteria and other microorganisms in gases and liquids and on the surfaces of solid objects. In general, photocatalysis methods involve the photoexcitation of photocatalytic compounds, for example, catalytic n-type semiconductor particles such as TiO2 particles, with ultraviolet (UV) light to activate the photocatalyst, which then participates in reduction/oxidation reactions with matter adsorbed to or in the near vicinity of the surface of the particles. The reduction/oxidation reactions produce highly reactive hydroxyl radicals which oxidize and destroy bacteria and organic compounds in the gas or liquid or on the surface(s) being treated, such as bacteria and other organic substances associated with, for example, tooth decay, gum disease, denture stomatitis and halitosis/malodor.
In the past, photocatalysis methods have generally only been performed in a dentist's offices by either a dentist or a dental hygienist using a specialized UV laser(s) or some other optical device(s) which emits a controllable, directed beam of UV light. More recently, however, there have been proposals to manufacture and sell UV photocatalysis devices to the general public, e.g., a toothbrush containing a UV light radiating device, together with toothpastes and/or mouthwashes containing photocatalytic particles, such as TiO2. In such toothbrushes, the UV light emitted by a UV laser diode, for example, passes through a light guide to the end of the toothbrush which brushes the teeth where this light is emitted into the user's mouth by, for example, lenses implanted among the bristles or through fiber optic bristles that form at least part of the brush bristles. The bristles mechanically facilitate removal of plaque and/or other organic materials from the teeth and the gums during brushing, similar to brushing with a conventional toothbrush, while the UV light is emitted directly to illuminate photocatalytic particles distributed on the surfaces of the teeth and the gums, thereby providing both a conventional cleaning mechanism as well as a photocatalytic cleaning mechanism.
The currently UV photocatalytic toothbrushes which are marketed to consumers, however, have a number of significant problems, not the least being the potential hazards associated with such devices. For example, in the generally preferred wavelength range of 280 mm to 400 mm, UV light at any power level is typically capable of damaging human skin including the tissue of human eyes. Compounding this problem is the fact that UV light within this wavelength range is nearly invisible to a user or patient, so that it is difficult to determine where the emitted UV beam is directed or aimed. In addition, the duration of irradiation of the catalytic particles, at any particular location within the mouth, is typically very short during the normal toothbrushing process, thus requiring higher power levels of UV radiation in order to obtain effective catalytic reactions. This problem is further compounded by the normal deterioration of the light transmission capability of the brush end elements, such as the lenses and the fiber optic elements, over time. Higher emitted power levels are generally called for in order to achieve satisfactory performance.
Up until now it is in fact the potential hazards of UV radiation that has limited the use of the UV dental hygiene processes to dentists and oral hygienists and the practical application of these methods to consumer toothbrushes and devices accordingly faces significant hurdles. For example, all medical or dental devices emitting ultraviolet light, and in particular within the wavelength range of 280 mm to 400 mm, are under Food and Drug Administration (FDA) control and licensing. In addition, all laser devices emitting coherent radiation of 1 milliwatt or more in the visible wavelengths, and all devices emitting laser radiation at any power level in the non-visible wavelengths, such as the UV and IR wavelengths, are presently prohibited from being sold to the general public.
- SUMMARY OF THE INVENTION
The present invention, however, provides a solution to the above described as well as other related problems associated with the prior art products and methods.
Wherefore, it is an object of the present invention to overcome the above mentioned shortcomings and drawbacks associated with the prior art.
A primary object of the invention is to provide a toothbrush which emits radiation, in the near ultraviolet region of the electromagnetic spectrum, to oxidize and destroy potentially harmful bacteria and/or other contaminants or compounds contained within the mouth.
Another object of the invention is to provide a toothbrush that will activate a photo catalyst deposited on the teeth and the gums of the person utilizing the toothbrush during normal brushing.
A further object of the invention is to provide a toothbrush which emits blue light within the 420 nm to 480 nm wavelength band, of the electromagnetic spectrum to avoid the normal hazards associated with using UV radiation as well as the corresponding FDA restrictions.
Yet another object of the invention is to provide a toothbrush in which the radiated blue light emissions may be amplitude modulated from 0% to 100% at a frequency of between about two (2) and about two hundred (200) Hertz, more preferably between about 6 and about 60 Hertz and most preferably between about 10 and about 30 Hertz, with an average optical output power level of less than 5 watts.
A still further object of the invention is to provide a toothbrush which is relatively inexpensive to manufacture which has a power source that is light weight and can be readily recharged or replaced as needed.
BRIEF DESCRIPTION OF THE DRAWINGS
As used herein, the term “average optical output power level” means that the optical output power may briefly exceed 5 watts on modulation peeks how ever the total integrated power level over a time period of 1 second will not exceed 5 watts.
The invention will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a diagrammatic perspective view of a toothbrush according with the teachings of the present invention;
FIG. 2A is a diagrammatic transverse cross sectional side view of the toothbrush of FIG. 1;
FIG. 2B is a diagrammatic transverse cross sectional side view of the toothbrush of FIG. 1;
FIG. 3A is an enlarged diagrammatic side elevational view of a brush head with the blue light source extending further away from the base of the head, then the embodiments of FIGS. 2A and 2B, so that the light is emitted adjacent the free ends of the bristles of the toothbrush;
FIG. 3B is a diagrammatic transverse cross sectional side view of an alternative embodiment of a toothbrush which comprises a handle having a removal brush head;
FIG. 3C is a diagrammatic transverse cross sectional side view of an alternative embodiment of a toothbrush in which the handle is integral with the brush head;
FIG. 3D is a diagrammatic enlarged view of the brush head of FIG. 3C;
FIG. 4A is a diagrammatic enlarged view of an alternative embodiment of the brush head in which each individual blue light source is associated with a group of bristles attached to the brush head to supply the blue light along the length of the bristles; and
DETAILED DESCRIPTION OF THE INVENTION
FIG. 4B is a diagrammatic enlarged view of a further embodiment of a brush head have each blue light source associated with a group of bristles attached to the brush head.
Turning now to FIG. 1, a diagrammatic representation of a toothbrush 10, according to the present invention, is shown. As illustrated therein, the toothbrush 10 includes is includes a handle 12 having a grip 14 at its proximal end to be held in the user's hand while using the toothbrush 10 and a brush head 16, typically including one or more groups of bristles 18, located at the distal or working end of the handle 12. As also illustrated in FIG. 1, the head 16 further includes one or more blue light emitters 20 that emit blue light 22 in the 450 nm +/−30 nm (nanometer) wavelength band, that is, in the wavelengths between 420 nm and 480 nm and at an average power level of less than 5 watts. Preferably the blue light has an average power level of between about 0.25 and about 1 watt and more preferably an average power level of between about 0.5 and about 0.95 watts.
In some applications, the blue light output from the emitters 20 may comprise solely a continuous emission of blue light having a combined power level of less than 5 watts, while in other applications the blue light output from the emitters 20 may comprise a modulated blue light emission having a frequency of between about two (2) and about two hundred (200) Hertz, more preferably between about 6 and about 60 Hertz and most preferably between about 10 and about 30 Hertz, having an average combined power level of less than 5 watts. For other applications, the blue light output from the emitters 20 may comprise a first blue light component which is a continuous emission of blue light and a second blue light component which is a pulsed blue light emission at a frequency typically between two (2) and two hundred (200) Hertz a few Hertz and a few hundred Hertz, more preferably between about 6 and about 60 Hertz and most preferably between about 10 and about 30 Hertz. For such combined continuous and pulsed blue light emission, the combined total emission must not exceed an average output which is greater that 5 watts. It is to be appreciated that the 420 nm to 480 nm wavelength band is within the visible “blue light” portion of the electromagnetic spectrum and is, therefore, below the UV light spectrum normally employed during conventional dental hygiene processes conventionally carried out by dentists and dental hygienist, thereby avoiding the normal hazards associated with using UV radiation as well as the corresponding FDA restrictions.
The presently preferred photocatalytic agents, for use with radiation within the 420 nm to 480 nm “blue light” band include, for example, modified TiO2 semiconductor type materials and possibly other catalytic n-type semiconductor particles as well as various organic dyes already known in the art as being photocatalytically responsive to blue light radiation.
As illustrated in FIGS. 1, 2A, 3A and 3B and as will be described further in the following description, the blue light emitters 20 emit blue light 22 in a direction generally perpendicular to an upper surface 24 of the head 16 thereby to radiate the blue light 22 into the mouth cavity of the person brushing his or her teeth, that is, the blue light is generally directed toward the teeth, the gums, and the tongue, being contacted by the bristles 18 as the toothbrush is used to brush the teeth. The blue light emitters 20 may comprise one or more blue light sources 26A, such as blue light emitting diodes or blue light emitting organic light emitting diodes, or any other type of blue light emitting device located either on, within or partially recessed within the upper surface 24 of the head 16 to facilitate directly emitting the blue light 22. Alternatively, the blue light source(s) 26A may be located within the body of the head 16 or within handle 12 with the blue light 22 being conducted along the handle and/or body to the blue light emitters 20 where the blue light is finally emitted. One or more internal passages or light conductive elements, such as reflective surfaces, blue conductive fiber optics, lenses and/or any combination thereof are provided in the handle and/or body to facilitate transmission of the blue light to the blue light emitters 20. In such embodiments of a toothbrush 10, the blue light source or sources 26A will be described or defined as being located contiguous to the head 16, such as at the top surface 19 of head 16 or within the body of head 16, and it should be noted that for purposes of the present descriptions, the term contiguous is taken as meaning “in physical contact with” or “near, next to, or adjacent”.
In other embodiments, such as is illustrated in FIGS. 2B, 3C and 3D, the blue light source or sources 26A may be located non-contiguously with head 16, such as in handle 12, with the blue light 22 being conducted along the handle to blue light emitters 20 located within the head 16 by means of blue light optical conductors 26B comprising, for example, of blue conductive fiber optic elements or lenses, reflective surfaces, passages or conductive “pipes” comprising blue conductive materials, and/or any combination thereof, which form a one or more paths that conduct the blue light 22 from the blue light source or sources 26A to the blue light emitters 20 where the light is emitted.
For example, one or more blue light sources 26A may be located in handle 12 at a position just below a neck 28, formed at a junction between the handle 12 and the head 16. According to one exemplary embodiment, such as illustrated in FIGS. 3C and 3D, the neck 28, the head 16 and possibly portions of the handle 12 are constructed, for example, of a blue transparent material or with one or more blue transparent passage(s) or blue light conductive “pipe” which facilitate passage of the blue light 22 through the neck 28 to the head 16 and thereafter radiated from the blue light emitters 20. In the embodiment illustrated in FIGS. 3C and 3D, the portions of the neck 28 through which blue light 22 is transmitted comprises a suitable blue transparent material, as does the body of the head 16. The interior of head 16 includes a blue reflective surface 30 formed as facets 30F wherein the blue light reflective properties of reflective surface 30 is formed, for example, by a coating applied at least between the surfaces of facets 30F and an over-mold 30O of a different material forming the back regions of the head 16. The reflective surface 30 may also be formed, for example, by the optical interface of the body 16 and the over-mold 30O materials in the region of facets 30F.
As indicated in FIGS. 3C and 3D, the blue light 22 passing through neck 28 is reflected by facets 30F and redirected by the facets 30F from an arrival path, supplied along and co-linear with the neck 28, to a direction generally parallel to the bristles 18, that is, to and through the upper surface 24 of the head 16. It should be noted with regard to this embodiment that other scattering of the blue light 22 in other directions, such as through the distal end of head 16, would provide catalytic activity in other areas of the mouth, but would require attention during design to avoid unwanted emissions of blue light from toothbrush.
It will be recognized that the reflection of the blue light from its arrival path from handle 12 to the direction parallel with the bristles 18 may also be accomplished by curved or flat surfaces, rather than by faceted surfaces.
In an alternate embodiment, as illustrated in FIG. 2B, the blue light source or sources 26A are again located in the handle 12 which illuminate the blue light emitters 20 provided in the head 16, via a blue light conductive path, wherein the blue light conductive path comprises blue light optical conductors 26B including, for example, blue conductive fiber optic elements or lenses, tunnel-like passages or conductive “pipes” comprising blue conductive materials and/or any combination thereof. The blue light 22 is then emitted via the blue light emitters 20 in the upper surface 24, such as lenses, the ends of optical fibers or through optically conductive bristles 18.
Turning now to the bristles 18, it has been described above that the bristles 18 may comprise either conventional bristles 18, such as found in conventional toothbrushes, and the blue light 22 may be radiated the from blue light emitters 20 located on or in the top surface 24 of the head 16, as was discussed above. In other embodiments, however, the blue light emitters 20 in or one the top surface 24 of the head 16 may comprise wholly, or in part, blue light emitting bristles 18E containing a blue light conductive material. As illustrated in FIG. 4A, the blue light source of sources 26A may be located either in the head 16, at the bases of emitting bristles 18E, to illuminate emitting bristles 18E directly, or, as illustrated in FIG. 4B, may be located in handle 12 with the blue light 22 being conducted to the bases of the emitting bristles 28E by blue light optical conductors 26B. In the latter case, the emitting bristles 26E may comprise the same material as the blue light optical conductors 26B or may be continuations of the blue light optical conductors 26B. It should also be noted that the emitting bristles 18E may be coated or otherwise provided with a reflecting outer surface to prevent or minimize the loss or escape of the blue light 22 out through the sides of the emitting bristles 18E, and the head 16 may likewise be provided with a reflective blue light containment surface to prevent or minimize leakage or loss of the blue light 22.
Next, it will be noted from the above descriptions of the toothbrush 10 that while the blue light emitters 20 are located in or on the head 16, the blue light source or sources 26A may be located either in the head 16 or in the handle 12. In one instance, therefore, blue light 22 must be conducted from the blue light source or sources 26A located within the handle 12 to the head 16 and, in the other instance, electrical power, such as from a battery 32, must be conducted from the handle 12 to the head 16 for supplying electrical power to the blue light source or sources 26A. It must also be noted, however, that in certain implementations, such as those illustrated in FIGS. 2B, 3C and 3D for example, the neck 28 which is formed between the head 16 and the handle 12 may form a disconnectable junction or connection 34 between the head 16 and the handle 12 to allow the head 16 to be removed from the handle 16. This is a common feature in many conventional toothbrushes, particularly in conventional battery powered toothbrushes wherein a battery and an electric motor vibrate or rotate the toothbrush head. This design facilitates replacement of a worm or old head 16 with a new head 16 or a different head 16 having, for example, a different function, a different arrangement, a different type of bristles 18 and/or different blue light emitters 20.
In those instances wherein the blue light source or sources 26A are located in handle 12, the path between the blue light source or sources 26A and the head 16 will include the appropriate blue light optical connectors 34L, at junction 34, to allow the optical path to be repeatedly disconnected and reconnected in a reliable manner. Connectors 34L may, for example, comprise lenses, fiber optic connectors or appropriately shaped ends in those implementations wherein the optical light path comprises the material of the handle 12 and the head 16 or a tunnel passage therethrough.
In those instances wherein the blue light source or sources 26A are located in the head 16, the blue light source(s) 26A will typically be provided with electrical power from one or more batteries 32 located within an internal cavity 36 of the handle 12 and the supply of electrical power to the blue light source or sources 26A will typically be controlled by a switch 38, e.g., a “on/off” switch, located at an appropriate position on the handle 12. The circuitry will further include leads 32L running from the handle 12 and through the neck to the head 16 and the leads 32L will typically include appropriate electrical connectors 34L at junction 34 which facilitate repeated disconnection and reconnection in a reliable manner.
In this regard, it should be noted that batteries 32 may be of any type meeting the power, storage and/or size requirements while still being small enough to reside in within the handle 12 and to provide the necessary levels of current to the blue light sources 20 for the required duration, such a NiCad, NiMiH, lithium ion, or lithium polymer batteries which typically may be rechargeable by electrical current supplied from a wall socket. For this reason, the handle 12 will typically also include a charging circuit 32C that can be connected to a direct or indirect source of electrical current supplied from a conventional wall socket, such as by a connector or by an induction coupling device. An active and passive interlock system will be employed to prevent normal operation during battery recharge. This interlock system may consist of mechanical keying of electrical connections and or electronic control of the toothbrush electronics by the charging circuit. It should also be noted that advances in battery technology may allow one or more batteries 32 to be located within the head 16 to facilitate the use of interchangeable heads 16, with the corresponding connections for the switch 38 and the recharging circuits 32C passing through the neck 15 to the handle 12. As an alternative source, the power source or batteries may be AA or AAA alkaline, lithium, or carbon zinc batteries which are commercially available and readily replaceable by the user of the toothbrush.
The toothbrush 10, according to the present invention, will typically further include a control circuitry 38 which will typically be located in the handle 12 and normally include functions such as a timer circuitry, which times the duration(s) of use of the toothbrush 10 while brushing, an on/off duty cycle of the blue light source or sources 26A, a replace battery indicator, and so on. The control circuitry 38 may also include blue light source 26A control circuitry, which may be connected with one or more sensors 40S, located in the head 16, for detecting when the head 16 is actually located within a user's mouth, thereby reducing the possibility of the blue light being inadvertently emitted except when the toothbrush is actually located within the mouth of the user. The Sensor(s) 40S could include, for example, sensors for measuring or detecting conductivity, temperature, ambient light, or some other parameter indicating that the head 16 is in the mouth of a user, and the handle 12 may include a sensor for sensing the warmth or pressure of the user's hand before the blue light source or sources 20 can be activated.
It should also be noted that the toothbrush 10 may further include a motor (not shown) which moves, vibrates and/or rotates the head 16 in the manner of conventional powered toothbrushes, which may in turn effect the arrangements for supplying the blue light 22 to the blue light emitters 20 in as much as the mechanical structure between the handle 12 and the head 16 in such toothbrushes includes a moving mechanical joint. In such implementations, therefore, it may be preferable to place the blue light source or sources 26A in the handle 12 and communicate the blue light 22 to the blue light emitters 20 in the head 16 by optical paths that are typically less affected by moving mechanical joints than are electrical conductors.
Lastly, it should be noted that the provision of the replaceable head 16 permits the use of other forms of blue light emitting heads 16 containing blue light emitters 20 as described herein above, but shaped for other purposes than specifically as a toothbrush, such as a wand specifically designed and/or intended for blue light irradiation of a photocatalytic agent distributed on the surfaces of the teeth and the gums. In a further example of an alternate arrangement of the head 16, the head 16 may be designed to hold and manipulate flossing thread or string, thereby allowing flossing to be carried out at the same time as a blue light photocatalytic process.
It will be appreciated that various changes and/or modifications to the present invention may be made by those of ordinary skill in the art without departing from the spirit and scope of the present invention which is set out in more particular detail in the appended claims. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is supplied by way of example only, and is not intended to be limiting of the invention as described in the appended claims.