Golf club head

1. A golf club head comprising:

a crown portion;

a face portion; and

a sole portion,

wherein the crown portion includes:

a thick region provided at least in a location extending substantially entirely from a toe side to a heel side along a boundary with the face portion; and

at least one thin region that is disposed further on a back side than the thick region and is smaller in thickness than the thick region,

wherein a length of the thick region from the boundary in a face-back direction is greater in a vicinity of a center in a toe-heel direction than at the toe side and the heel side,

wherein, in a peripheral portion of the crown portion, a lateral thick portion that is a part of the thick region is disposed on at least one of the toe side and the heel side relative to the at least one thin region, and

wherein the lateral thick portion is formed to have a length in the toe-heel direction that decreases moving toward the back side.

2. The golf club head according to claim 1 , further comprising a hosel portion, wherein a percentage R (=S 1 /S 2 ) that a projected area S 1 of the at least one thin region occupies in an area S 2 , which is a sum total of a projected area of the crown portion and a projected area of the hosel portion, is 25 to 70%.

3. The golf club head according to claim 1 , further comprising:

a plurality of thin regions that are arranged side-by-side from the toe side to the heel side,

wherein a distance between the boundary and a thin region disposed in a vicinity of the center in the toe-heel direction is longer than a distance between the boundary and thin regions disposed on the toe side and the heel side.

4. The golf club head according to claim 3 , wherein the crown portion is provided with a gap thick portion disposed between each of the plurality of thin regions.

5. The golf club head according to claim 4 , wherein the plurality of thin regions includes a first thin region, a second thin region and a third thin region, and

wherein the first thin region is disposed at the toe side of the crown portion, the second thin region is adjacent to the first thin region and disposed at a middle of the crown portion, and the third thin region is adjacent to the second thin region and disposed at the heel side of the crown portion.

6. The golf club head according to claim 5 , wherein the second thin region is formed in a fan shape that expands toward the back side from a face side.

7. The golf club head according to claim 1 , wherein the crown portion is provided with a gap thick portion disposed between each of the thin regions.

8. The golf club head according to claim 7 , wherein the plurality of thin regions includes a first thin region, a second thin region and a third thin region, and

wherein the first thin region is disposed at the toe side of the crown portion, the second thin region is adjacent to the first thin region and disposed at the middle of the crown portion, and the third thin region is adjacent to the second thin region and disposed at the heel side of the crown portion.

9. The golf club head according to claim 8 , wherein the second thin region is formed in a fan shape that expands toward the back side from a face side.

10. The golf club head according to claim 1 , wherein a boundary of the thick region with the at least one thin region extends in the toe-heel direction.

11. The golf club head comprising:

a crown portion;

a face portion; and

a sole portion,

wherein the crown portion includes:

a thick region provided at least in a location extending substantially entirely from a toe side to a heel side along a boundary with the face portion; and

a plurality of thin regions that are disposed further on a back side than the thick region and are thinner than the thick region,

wherein the plurality of thin regions are arranged side-by-side from the toe side to the heel side, and

wherein a thin region disposed in a vicinity of a center in a toe-heel direction is larger in thickness than thin regions disposed on the toe side and the heel side.

12. The golf club head according to claim 11 , further comprising a hosel portion, wherein a percentage R (=S 1 /S 2 ) that a projected area S 1 of the thin region occupies in an area S 2 , which is a sum total of a projected area of the crown portion and a projected area of the hosel portion, is 25 to 70%.

13. The golf club head according to claim 11 , wherein a boundary of the thick region with the at least one thin region extends in the toe-heel direction.