Brush body and toothbrush including brush body

Abstract

A brush body of a toothbrush includes bristle bundles, each formed by a plurality of filaments. Each filament includes a core, which contains a conductive material, and an insulative sheath, which covers a side of the core. Each bristle bundle includes a basal portion at which basal ends of the cores are fused, solidified, and integrated with one another. The bristle bundle also includes a distal portion, which is formed by a distal end of each core. A ratio of the conductive material at the basal portion is equal to a ratio of the conductive material at the distal portion.

1 . A brush body comprising a bristle bundle including a plurality of filaments, wherein
 each filament includes a core, which contains a conductive material, and an insulative sheath, which covers a side of the core;   the core includes a distal end and a basal end projecting out of the sheath in a longitudinal direction;   the bristle bundle includes a basal portion, at which the basal ends of the cores in the filaments are fused, solidified, and integrated with one another;   the bristle bundle includes a distal portion, which is formed by the distal end of each core of the filaments; and   a ratio of the conductive material at the basal portion of the bristle bundle is equal to a ratio of the conductive material at the distal portion of the bristle bundle.   
     
     
         2 . The brush body according to  claim 1 , wherein the basal portion of the bristle bundle has a larger diameter than a portion of the bristle bundle corresponding to the sheaths. 
     
     
         3 . The brush body according to  claim 1 , wherein the bristle bundle is one of a plurality of bristle bundles, and the basal portions of the bristle bundles are integrated and connected with one another. 
     
     
         4 . The brush body according to  claim 1 , wherein the bristle bundle is one of the plurality of bristle bundles, the brush body further comprises a conductive member that connects the basal portions of the bristle bundles are connected with one another, wherein the conductive member has a smaller volume specific resistance than the basal portions. 
     
     
         5 . The brush body according to  claim 4 , wherein the conductive member is a base which receives the bristle bundles. 
     
     
         6 . The brush body according to  claim 5 , wherein the basal portions of the bristle bundles are integrated with the base. 
     
     
         7 . The brush body according to  claim 1 , wherein the basal portion of the bristle bundle where only the basal ends of the cores are fused and integrated with one another. 
     
     
         8 . The brush body according to  claim 7 , wherein the cores are formed from a mixture of the conductive material and an insulative material, and the ratio is a ratio of the conductive material in the mixture. 
     
     
         9 . A toothbrush comprising the brush body according to  claim 1 . 
     
     
         10 . The toothbrush according to  claim 9 , further comprising a vibration actuator for vibrating the brush body. 
     
     
         11 . A brush body comprising a bristle bundle including a plurality of filaments, wherein
 each filament includes a core, which contains a conductive material, and an insulative sheath, which covers a side of the core; and   the bristle bundle includes a fused resin terminal, which is formed by fusing and integrating only the cores of the filaments without fusing the insulative sheath.   
     
     
         12 . A method for manufacturing a brush body comprising:
 preparing a bristle bundle by bundling a plurality of filaments, wherein each filament includes a conductive core, which includes a distal projection and a basal projection, and an insulative sheath, which covers a portion of the core excluding the distal projection and the basal projection;   fusing and integrating the basal projections of the cores of the filaments without fusing the insulative sheaths to form a fused resin terminal of the bristle bundle; and   electrically connecting the fused resin terminal of the bristle bundle to a head of the brush body.   
     
     
         13 . The manufacturing method according to  claim 12 , wherein the basal projection of the core is longer than the distal projection.