1. A golf club head having a hollow comprising
a face portion whose front face defines a clubface for hitting a ball,
the face portion comprising a central thicker portion provided in a center region thereof and a peripheral thinner portion provided around the central thicker portion and having a thickness smaller than that of the central thicker portion,
the peripheral thinner portion having an inner surface facing the hollow,
the inner surface of the peripheral thinner portion comprising a first region and a second region,
the first region being provided with a plurality of first grooves which extend straightly in a certain direction, and
the second region being provided with a plurality of second grooves which extend straightly in the different direction of first grooves.
2. The golf club head according to claim 1, wherein
first grooves extend in parallel with each other.
3. The golf club head according to claim 1 or 2, wherein
second grooves extend in parallel with each other.
4. The golf club head according to claim 1 or 2, wherein
first grooves extend at right angles to second grooves.
5. The golf club head according to claim 1 or 2, wherein
first grooves and second grooves each have a groove depth in a range of from 0.02 to 0.80 mm and a groove width in a range of from 0.1 to 3.0 mm.
6. The golf club head according to claim 1 or 2, wherein
first grooves and second grooves each have an arc shape in a cross section intersecting with the longitudinal direction of each groove, and
the arc shape has a radius of curvature of from 1.0 to 5.0 mm.
7. The golf club head according to claim 1 or 2, wherein
pitches between adjacent first grooves are in a range of from 1.0 to 1.5 times groove widths of first grooves, and
pitches between adjacent second grooves are in a range of from 1.0 to 1.5 times groove widths of second grooves.
8. The golf club head according to claim 1 or 2, wherein
in a front view under a standard state that the club head is placed on a horizontal plane, so that a clubshaft center line inclines at its lie angle within a vertical plane, and the clubface inclines at its loft angle with respect to the vertical plane,
first grooves incline at angle of from 80 to 100 degrees with respect to the horizontal plane, and
second grooves incline at angle of from 0 to 10 degrees with respect to the horizontal plane.
9. The golf club head according to claim 8, wherein
first grooves are provided with a toe side region and a heel side region of the inner surface of the peripheral thinner portion, and
second grooves are provided with a crown side region and a sole side region of the inner surface of the peripheral thinner portion.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A film forming apparatus, comprising:
a reactor evacuated from an evacuation port, said reactor accommodating therein a stage;
an evacuation system connected to said evacuation port;
a first source supply line supplying a first gas containing Ti to said reactor via a switching valve;
a second source supply line supplying a second gas containing Si to said reactor;
a third source supply line supplying a third gas containing N to said reactor; and
a controller controlling said switching valve, such that first and second supplying steps are conducted alternately and repeatedly, said first supplying step supplying said first gas, said second gas and said third gas to said reactor, said second supplying step supplying said second gas and said third gas to said reactor,
said controller interrupting supply of said first gas to said reactor intermittently and repeatedly.
2. A film forming apparatus as claimed in claim 1, wherein said switching valve directs said first gas to a pre-flow line during an interval in which supply of said first gas to said reactor is interrupted.
3. A film forming apparatus as claimed in claim 1, wherein said controller continuously interrupts supply of said first gas to said reactor over a duration such that a partial pressure of said first gas in said reactor substantially decreases.
4. A film forming apparatus as claimed in claim 1, further comprising a pre-flow line provided between said switching valve and said evacuation system to direct said first gas to said evacuation system.