FIELD OF THE INVENTION

The present invention relates to dental and mouth hygiene. In a particular form the present invention relates to a toothbrush that modifies the oral environment surrounding the teeth being cleaned.

BACKGROUND OF THE INVENTION

Use of a toothbrush made up of a handle and a head containing a number of flexible bristles is of course well known. In order to remove plaque and the like, the bristles are agitated over the teeth in an oscillatory motion thereby disengaging the material from the teeth and preventing tooth decay and mouth odour.

The common toothbrush has been improved over time by incremental developments in areas such as the strength and arrangement of bristles and also the configuration and flexibility of the handle. Other advancements in toothbrush technology have included bristles that are either rotated or agitated by electrical motors. However, in all these case the fundamental design of the common toothbrush all relate to a device which is designed to remove plaque from teeth by physical removal.

It is an object of the invention to provide a toothbrush incorporating the capability of both physically cleaning teeth and modifying the properties of an oral region in the environment of the teeth being cleaned.

SUMMARY OF THE INVENTION

In a first aspect the present invention accordingly provides a toothbrush including: a head including a plurality of bristles to brush teeth;

a handle for holding and operating said toothbrush; and current generation means to generate an electric current in an oral region in the environment of teeth being brushed by said toothbrush.

The negative electrical current generated in the environment of the teeth being brushed facilitates the removal of the positively charged ions in the plaque and furthermore the current helps eliminate harmful bacteria in the mouth thereby improving the effectiveness of the toothbrush and overall oral hygiene.

Preferably, said current generation means includes a pair of current conducting portions located at the head of said toothbrush to deliver said electric current substantially in the head region of said toothbrush in the action of brushing said teeth.

This greatly improves the effectiveness of the toothbrush as the current is delivered very close to the oral region where the teeth are being brushed.

Preferably, said pair of current conducting portions are located in a central region of said bristles.

In this manner, the electrical current will be caused to flow and disperse more widely through the foam which develops in the mouth as a result of brushing.

Preferably, said current generation means includes a battery to power said current generation means.

Preferably, said battery is located in a battery receiving portion of said toothbrush. Preferably said battery receiving portion is located internally within the handle of said toothbrush.

This greatly improves the utility of the toothbrush as it does not require a separate power supply.

Preferably, said current generating means includes a current generating circuit powered by said battery.

Preferably, said current generating circuit is located within the handle of said toothbrush

Again this greatly improves the convenience of the toothbrush as the toothbrush includes integrally all the essential elements to generate the required current.

Preferably, said current generating circuit includes an actuator to actuate said current generator circuit, said actuator located on said handle of said toothbrush.

Preferably, said pair of current conducting portions are connected to said current generation circuit by electrical wires recessed within a stem portion of said toothbrush located between said head and said handle.

This has the combined effect of insulating the electrical wires and improving the appearance of the toothbrush.

Preferably, each of said current conducting portions is an exposed wire section of each of said respective electrical wires.

This improves the manufacturability of the toothbrush as the same wire is used to deliver the electric current to the mouth and transfer current from the current generating circuit.

Preferably, said head is removably mounted to said handle.

Accordingly _/ when the bristles wear out it is not necessary to replace the entire toothbrush as only the head requires replacement resulting in cost savings to the consumer.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention will be discussed with reference to the accompanying drawings wherein: FIGURE 1 is an disassembled perspective view of a toothbrush with the head detached according to a preferred embodiment of the present invention;

FIGURE 2 is a perspective view of the current generating circuit incorporated into the toothbrush illustrated in Figure 1;

FIGURE 3 is a perspective view of the toothbrush illustrated in Figure 1 with the head attached;

FIGURE 4 is a side sectional view of the toothbrush illustrated in Figure 1 through AA with the top cover removed and depicting the electronics in schematic from;

FIGURE 5 is a top sectional view of the toothbrush illustrated in Figure 1 through BB also depicting the electronics in schematic form; and

FIGURE 6 is a circuit schematic of the current generation circuit employed in the toothbrush illustrated in Figure 1.

In the following description, like reference characters designate like or corresponding parts throughout the several views of the drawings.

DESCRIPTION OF PREFERRED EMBODIMENT

Referring now to Figures 1 to 5, there is shown a toothbrush 100 according to a preferred embodiment of the present invention. Toothbrush 100 includes a handle 110 and an integrally formed stem portion 160 and head 120 forming a detachable or removable head section 300 which incorporates a plurality of

flexible bristles 130. Handle 110 includes a cavity or recess 160 having a cover 140. In recess 160 is located current generating circuit 200 including battery 230, transistor element 240, resistor 250 and switch 260 actuated by actuator 150 and light emitting diode 270 which indicates when the current is flowing through circuit 200 and hence also battery 230 charge.

Electrical wires 210, 220 travel through stem portion 160 and terminate at one end in contact points 210b, 220b located in a recess region 116 located at the end of stem portion and at the other end in exposed wire sections 210a, 220a located in peripheral side portions of head 120 in a central region of the bristles 130 (as best seen in Figure 5). When head section 300 is attached to handle 110, contact points 210b, 220b further engage with resilient contact tongue elements 215, 225 (as best seen in Figure 2) located either side of a central ridge region 115 which is shaped to match a corresponding mating recess 116 at the end of stem portion 160 in head section 300. Cylindrical dowel or plug portion 117 also engages with a cylindrical channel or aperture 118 also located in the end of stem portion 160 to ensure that the head section 300 remains fixed to the handle 110 during brushing

When head section 300 is connected to handle 110, current generating circuit 200 functions to generate a current between exposed wire sections 210a, 220a during the brushing of teeth and hence generate an electrical current in an oral region in the environment of the teeth being brushed by the toothbrush.

Referring now to Figure 6, current generating circuit 200 is depicted in detailed schematic form. Circuit 200 is driven by a potential difference of 12V provided by battery 230 at plus terminal 231 and negative terminal 232 respectively. Although a disposable battery is employed in this preferred embodiment, clearly rechargeable batteries or indeed an independent power

supply supplied by mains power is contemplated to be within the scope of the present invention.

Negative terminal 232 of battery 230 is connected to the base of transistor 240 and furthermore to exposed wire section 210a which is positioned on the head

120 of toothbrush 100 as described previously. Plus terminal 231 is connected to the emitter terminal of transistor 240 via switch 260 and light emitting diode 270. The output from the collector of transistor 240 is passed through a

330 Ω resistor 250 to form the positive output terminal of the current generating circuit 200 which is located at exposed wire section 220a also positioned on the head 120 of toothbrush 100.

In use, a person brushing their teeth depresses actuator 150 thereby closing switch 260 and activating current generating circuit 200. Closing switch 260 causes a potential drop across the base and emitter terminals of transistor 240 thereby switching transistor 240 on resulting in current flowing between the base and emitter terminals of transistor 240 and also by virtue of the conductive medium between exposed portions 210A, 220A, current will flow between the collector and emitter terminals of transistor 240.

The conductive medium 300 between exposed portions 210A, 220A is provided in the action of brushing teeth when the interaction of the toothpaste and saliva forms a foam around the immediate area of bristles 130 and throughout an oral region in the environment of the teeth being brushed and more generally throughout the mouth. In this manner, current generating circuit 200 produces a current of approximately 500 μA between exposed wire sections 210a and 220a during brushing of teeth.

This electrical current is made up of electrons which originate from exposed portion 210a and in the process of brushing these electrons are dispersed

throughout the foam. The brushing motion facilitates the interaction and attraction between the generated negatively charged electrons and the positively charged ions in the plaque thereby facilitating their removal from the teeth. This results in cleaner teeth when compared to standard brushing due to the more effective removal of plaque build up.

Another additional benefit of the 500 μA current is that during the brushing process it serves to substantially eliminate harmful bacteria that reside in and around the teeth. As is well known, these bacteria are responsible for tooth decay and gingivitis. As would be apparent to those skilled in the art, electronic circuit 200 may be easily adapted to provide differing currents as required.

A brief consideration of the above described embodiment will indicate that the invention provides an extremely simple, economical toothbrush which is effective to significantly remove plaque from teeth during brushing and furthermore to eliminate and kill bacteria due to the current being generated in and around the teeth during brushing.

Although a preferred embodiment of the present invention has been described in the foregoing detailed description, it will be understood that the invention is not limited to the embodiment disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the invention as set forth and defined by the following claims.