BRIDGESTONE SPORTS CO., LTD.

A computer-implemented information processing method includes: obtaining first data representing a motion state of a predetermined motion performed by a target person; determining a direction of enhancement for the first data; and generating second data representing a target motion state of the predetermined motion, by modifying the first data to change in the direction, within an acceptable range set in advance for changing the first data.

A golf club head includes: a face formed of a metal; a sole formed of a carbon-fiber-reinforced resin; a crown formed of the carbon-fiber-reinforced resin; and a first weight member. The golf club head is hollow and has a volume ranging from 400 cc to 460 cc, inclusive. The sole includes a region that overlaps a lower portion of the face. The first weight member is detachably fixed, through a through-hole formed in the region, to a weight mounting portion disposed on the face close to the sole.

A golf ball includes a core, an intermediate layer, and a cover, in which dimples and a land portion are formed on a cover surface, the core is formed of a rubber composition containing a base rubber and an specific organic peroxide, the land portion includes a large number of land portion pieces, one land portion piece has a shape having at least three vertexes, the land portion includes a land portion piece having a specific shape formed by connecting the land portion piece in point contact with another adjacent land portion piece at each of the vertexes, an outer peripheral edge of the land portion piece having the specific shape includes a plurality of edge elements, and a ratio of the number of land portion pieces having a unique shape in which all the edge elements are formed in a predetermined curve is adjusted within a predetermined range.

The present invention provides a multi-piece solid golf ball including a core, an intermediate layer, and a cover, in which a film layer is formed between the intermediate layer and the cover, the film layer is formed of a resin composition containing an aziridine group-containing compound in a two-liquid curable polyurethane composition including a polyol component and a polyisocyanate component, and the cover is formed of a resin composition containing polyurethane as a principal component.

The present invention provides a golf ball including at least one coating layer on a surface of the golf ball having a large number of dimples, in which at least one layer of the coating layer is formed of a two-liquid curable urethane coating composition containing a polyol component and a polyisocyanate component, a molar ratio (NCO group/OH group) of an isocyanate group (NCO group) of the polyisocyanate component to a hydroxyl group (OH group) of the polyol component is from 0.50 to 0.88, and a 10% modulus of the coating layer based on measurement of JIS K 7161 (2014) is not more than 3.0 MPa.

The present invention provides a golf ball including a plurality of dimples and a land portion surrounded by the plurality of dimples. The land portion includes a large number of land portion pieces. One land portion piece has a shape having at least three vertexes. The land portion includes a land portion piece having a specific shape formed by connecting the land portion piece substantially in point contact with another adjacent land portion piece at each of the vertexes. Further, an outer peripheral edge of the land portion piece having the specific shape includes a plurality of edge elements. A ratio of the number of land portion pieces having a unique shape in which all the edge elements are formed with a predetermined curve is adjusted to a predetermined range of the number of all the land portion pieces constituting the land portion.

The present invention provides the rubber composition for a golf ball comprising (a) a base rubber, (b) a co-crosslinking agent which is an α,β-unsaturated carboxylic acid or a metal salt thereof or both, (c) a crosslinking initiator, and (d) an alcohol, wherein the amount of component (d) is from 0.1 to 10 parts by weight per 100 parts by weight of the base rubber (a) and the compounding ratio between component (b) and component (c) is set to at least 60 of E value that is represented by “E=the molar amount of component (b)/the molar amount of the active oxygen of component (c), and a golf ball using the rubber composition, in order to achieve the object that good durability of the golf ball to impact is maintained.

In a golf ball having a core and a cover of one or more layer, the core is a product molded under heat from a rubber composition which includes (a) a base rubber, (b) a co-crosslinking agent which is an α,β-unsaturated carboxylic acid and/or a metal salt thereof, (c) an organic peroxide, and (d) water, wherein the content of component (d) is set within a specific range and components (b) and (c) are included in relative amounts that satisfy a specific condition. The core has a specific compressive deformation and a specific hardness difference between the center and surface thereof. Owing to the large hardness difference in the internal hardness profile of the core, the ball exhibits low spin characteristics when hit, improving the flight performance, yet retains a good durability to impact.

In a multi-piece solid golf ball having a core, an intermediate layer encasing the core and a cover which encases the intermediate layer and has numerous dimples on an outside surface thereof, the intermediate layer is formed of a resin material comprising an ionomer resin as a base resin and an inorganic granular filler, the cover is formed of a urethane resin material, the core has a diameter of at least 38.0 mm, the core has specific deflection, the sphere obtained by encasing the core with the intermediate layer (intermediate layer-encased sphere) has a surface hardness on the Shore D hardness scale of at least 69, the ball has a surface hardness on the Shore D hardness scale of 62 or less, and the (intermediate layer thickness)/(core diameter) value is from 0.025 to 0.043, the (cover thickness)/(core diameter) value is from 0.014 to 0.027.

An information processing apparatus includes an acquisition unit configured to acquire a video of a swing of a golfer who strikes a golf ball with a golf club, a calculation unit configured to calculates a feature amount of the swing from the video, and a conversion unit configured to convert the feature amount into an estimated value of a behavior of a golf club head by substituting the feature amount into a conversion formula.