Electric shaver

1 . An electric shaver comprising:

a hand grip configured to be gripped by a user's hand,

a blade head provided on an upper end of said hand grip, said blade head carrying at least one shaving unit comprising an outer blade foil and an inner blade driven in a shearing engagement manner with said outer blade foil, said outer blade foil having a plurality of holes in which hairs are introduced, said outer blade foil being elongated and having a length and being curved along a width direction to form a generally C-shaped cross section, said outer blade foil being curved convexly and uniformly along its length to have a longitudinal curved outline,

wherein

a radius of curvature of said longitudinal curved outline is 150 mm to 350.

2 . The electric shaver as set forth in claim 1 , wherein

each of said holes of said outer blade foil has a shape having a major axis extending generally along the length of said outer blade foil,

said holes being arranged in such a pattern as the major axes get longer gradually as said holes near a longitudinal end of said outer blade foil from a middle part of said outer blade foil.

3 . The electric shaver as set forth in claim 2 , wherein

said holes are arranged in such a pattern as angles that the major axes of said holes form with a longitudinal-direction axis of said outer blade foil become larger as said holes near the longitudinal end of said outer blade foil from the middle part of said outer blade foil.

4 . The electric shaver as set forth in claim 2 , wherein each of said holes leaves a rounded shoulder for contact with a user's skin along its upper periphery,

radiuses of curvature of rounded shoulders become smaller as the holes near the middle part of the outer blade foil from the longitudinal end of the outer blade foil.

5 . The electric shaver as set forth in claim 1 , wherein said generally C-shaped cross section of said outer blade foil has a transverse arc having a uniform radius of curvature straddling an apex of said outer blade foil, the radius of curvature of said transverse arc being in a range of 1.5 mm to 3.5 mm.

6 . The electric shaver as set forth in claim 5 , wherein said blade head has a shape having a longitudinal axis and a transverse axis perpendicular to each other,

said blade head carrying two said shaving units each of which is elongated along the longitudinal axis of said blade head,

said two shaving units being disposed at opposite ends of said blade head along said transverse axis in a spaced relation to each other.

7 . The electric shaver as set forth in claim 6 , wherein

said generally C-shaped cross section of said outer blade foil has a transverse arc having a uniform radius of curvature straddling an apex of said outer blade foil,

said two shaving units being separated from each other at a distance of 0.5 to 2 times the radius of curvature of said transverse arc,

said distance being a distance between the apexes of said outer blade foils of said two shaving units.

8 . The electric shaver as set forth in claim 6 , wherein

each of said shaving units is supported by said blade head in a floating manner,

said two shaving units being capable of being depressed independently from each other by contact with a user's skin.

9 . The electric shaver as set forth in claim 8 , wherein said two shaving units are configured to generate different skin contact pressures when depressed by contact with a user's skin.

10 . The electric shaver as set forth in claim 6 , wherein

each of said two outer blade foils is supported by said blade head in a floating manner at its longitudinal opposite ends,

each of said outer blade foils being capable of being inclined against a spring load in such a manner as the longitudinal-direction axis of said outer blade foil intersects with the longitudinal axis of said blade head at a certain angle as well as capable of being vertically depressed against the spring load with its longitudinal-direction axis kept in parallel with the longitudinal axis of said blade head,

said two outer blade foils being capable of being inclined and depressed independently from each other relative to said blade head.