Toothbrush

Abstract

A toothbrush ( 1 ), comprising a tufted portion in which a plurality of tufts ( 4 ) to ( 7 ) formed of bristles made of synthetic resin are fixed to a head portion ( 3 ) of a toothbrush body made of synthetic resin, some of the plurality of tufts ( 4 ) to ( 7 ) having substantially the same horizontal cross sectional shape, and being arranged adjacent to each other in a central axis direction of the toothbrush in such a manner that a distance between centers of the tufts becomes substantially equal to a length in a width direction of a tooth.

1 : A toothbrush, comprising a tufted portion in which a plurality of tufts formed of bristles made of synthetic resin are fixed to a head portion of a toothbrush body made of synthetic resin,
 some of the plurality of tufts having substantially the same horizontal cross sectional shape, and being arranged adjacent to each other in a central axis direction of the toothbrush in such a manner that a distance between centers of the tufts becomes substantially equal to a length in a width direction of a tooth.   
   
   
       2 : The toothbrush according to  claim 1 , wherein the distance between centers of the tufts having the same cross sectional shape and arranged adjacent to each other in the central axis direction of the toothbrush in such a manner that the distance between the centers of the tufts becomes equal to the length in the width direction of a tooth is 5 to 12 mm. 
   
   
       3 : The toothbrush according to  claim 1 , wherein the tufts having the same cross sectional shape and arranged adjacent to each other in the central axis direction of the toothbrush in such a manner that the distance between the centers of the tufts becomes equal to the length in the width direction of a tooth are arranged at a side edge of the head portion. 
   
   
       4 : The toothbrush according to  claim 1 , wherein
 a horizontal cross sectional shape of the tufts having the same cross sectional shape and arranged adjacent to each other in the central axis direction of the toothbrush in such a manner that the distance between the centers of the tufts becomes equal to the length in a width direction of a tooth is a substantially triangular cross sectional shape; and   the tuft having a substantially triangular cross sectional shape is fixed to a head portion while a tapered part of a substantially triangular cross sectional shape directing in the same direction.   
   
   
       5 : The toothbrush according to  claim 4 , wherein the tuft having a substantially triangular cross sectional shape has a substantially triangular cross sectional shape which is tapered from the outer edge of the head portion toward the central axis of the toothbrush. 
   
   
       6 : The toothbrush according to  claim 4 , wherein the tuft having a triangular cross sectional shape has a horizontal cross sectional shape which is inscribed in a circle having a diameter of 1.4 to 4.5 mm. 
   
   
       7 : The toothbrush according to  claim 4 , wherein tufts having an elongated cross sectional shape extending in the central axis direction of the toothbrush are arranged between a plurality of tufts having a triangular cross sectional shape and arranged in the central axis direction of the toothbrush. 
   
   
       8 : The toothbrush according to  claim 7 , wherein the tuft having an elongated cross sectional shape is arranged outward in a width direction of the head portion relative to the tuft having a triangular cross sectional shape. 
   
   
       9 : The toothbrush according to  claim 7 , wherein a horizontal cross sectional shape of the tuft having an elongated cross sectional shape is substantially quadrilateral. 
   
   
       10 : The toothbrush according to  claim 1 , wherein bristles tips forming the tufts having the same cross sectional shape and arranged adjacent to each other in the central axis direction of the toothbrush in such a manner that the distance between the centers of the tufts becomes substantially equal to the length in a width direction of a tooth are tapered. 
   
   
       11 : The toothbrush according to  claim 10 , wherein the bristle whose tip is tapered is branched at a tip thereof. 
   
   
       12 : The toothbrush according to  claim 10 , wherein a tuft formed of bristles whose tips are rounded in a usual manner is fixed to a position closer to the central axis of the toothbrush relative to a position of the tufts formed of the bristles each having a tapered tip. 
   
   
       13 : The toothbrush according to  claim 1 , wherein a brush tip surface formed of tip surfaces of tufts is uneven. 
   
   
       14 : The toothbrush according to  claim 13 , wherein a central portion of a tip surface of each tuft formed of tip surfaces of bristles is formed into a convex shape. 
   
   
       15 : The toothbrush according to  claim 10 , wherein a length of the bristle having a tapered tip is substantially equal to or longer than a length of the bristle whose tip is rounded in a usual manner. 
   
   
       16 : The toothbrush according to  claim 1 , wherein the tuft is thermally bonded to the head portion. 
   
   
       17 : The toothbrush according to  claim 16 , wherein the number of the bristles of the tuft is substantially an integral multiple of the number of bristles which are picked out by a device for picking out bristles in the same amount when the tuft is thermally bonded to the head portion. 
   
   
       18 : The toothbrush according to  claim 16 , wherein a horizontal cross sectional area of the bristles of the tuft is substantially an integral multiple of a horizontal cross sectional area of bristles in an opening from which bristles are picked out by a device for picking out bristles in the same amount when the tuft is thermally bonded to the head portion.