Abstract: This invention provides a golf club head in which a plurality of scorelines are formed in its face surface at an equal pitch. Rounded portions are formed on the edges of the scorelines. Each region between adjacent scorelines includes a fine groove formation region in which N (N?2) fine grooves are formed to extend parallel to the scorelines and to align themselves in a direction perpendicular to the scorelines at an interval d (d?0). Letting S be the distance between the endpoints of the rounded portions of the adjacent scorelines, Wt be the sum total of the widths of all the fine grooves, A1 be the distance from the endpoint of the rounded portion of one scoreline of the adjacent scorelines to the fine groove formation region, A2 be the distance from the endpoint of the rounded portion of the other scoreline of the adjacent scorelines to the fine groove formation region, and Wmax be the maximum width of the widths of the fine grooves, 0?A1+A2<Wmax+d, |A1?A2|<(Wmax+d)/4, and Wt+d×(N?1)+A1+A2=S.

Abstract: This invention provides a method of manufacturing a golf club head by processing a head base body having a face base surface which becomes a face surface by finishing. The head base body includes a main body portion having the face base surface, and projecting portions which project from the main body portion. The method includes a finishing step of performing the finishing while the head base body is fixed in position by supporting the projecting portions, and a separation step of separating the projecting portions after the finishing.

Abstract: A golf club head according to this invention has scorelines formed in its face surface. A plated layer is formed on at least the face surface of a head base body before the scorelines are formed in the face surface, and the face surface is grooved to form the scorelines in it.

Abstract: A hollow golf club head according to this invention includes a face portion, a crown portion, and a sole/side portion including a sole portion and a side portion. The sole/side portion includes a thin region formed to traverse at least the sole portion from the toe side to the heel side, and thick regions formed on the side of the face portion and the back side, respectively, with respect to the thin region to be adjacent to the thin region. The golf club head further includes a rib which extends from the toe side to the heel side only in the thin region of the thin region and the thick region, and is connected to the side portion on the toe side and the side portion on the heel side.

Abstract: This invention provides a hollow golf club head including a face portion, a crown portion, and a sole/side portion including a sole portion and a side portion. This golf club head includes a rib which extends from the toe side to the heel side in the sole portion, and a weight portion which is provided in the sole portion on the side of the face portion with respect to the rib or the back side with respect to the rib, and increases the amplitude of vibration of the sole portion.

Abstract: This invention provides a putter head comprising a head body and a face insert mounted on a face surface of the head body. Slits are vertically aligned in multiple stages so as to extend in the face insert in a toe-to-heel direction. A depending portion is provided in the slit on a side of the face surface so as to reduce a vertical dimension of the slit. The slit is filled with a viscoelastic material.

Abstract: This invention provides an iron golf club head comprising a face surface with a plurality of scorelines formed in it, and an indicating portion which indicates at least the cross-sectional shape of the scoreline.

Abstract: A putter head includes a head main body having a depressed portion and a face insert disposed within the depressed portion so that the face insert is mounted in a face surface of the head main body. The face insert includes at least one low hardness portion and at least one high hardness portion. The face insert has a boundary face between the at least one low hardness portion and the at least one high hardness portion which is inclined relative to a back-to-forth direction of the putter head. The boundary face may decline toward the rear or may rise toward the rear. The face insert may comprise a plurality of the low hardness portions and a plurality of the high hardness portions so that the low and high hardness portions are arranged vertically in multiple layers. The sectional shapes taken perpendicularly to the back-to-forth direction of the high hardness portion and the low hardness portion may be substantially of a right triangle.

Abstract: This invention provides a hollow golf club head including a face portion, a crown portion, a sole/side portion which includes a sole portion and a side portion, and a weight member. The golf club head includes a recessed portion which is formed in the sole/side portion, and has an outer surface to which the weight member is attached, and a rib which is formed on the inner surface of the sole/side portion, and traverses the recessed portion across the peripheral edge defining the recessed portion.

Abstract: This invention provides a golf club head which includes a face portion, and has a volume of 400 cc or more. When the golf club head is disposed on a horizontal plane at a specific lie angle while the face portion is matched with the flight trajectory direction, and images of the face portion and the golf club head are projected onto a vertical plane from the front side of the face portion upon defining the flight trajectory direction as the projection direction, the area of a projected figure H of the golf club head is defined as HA, and the area of a projected figure F of the face portion is defined as FA. The golf club head satisfies 0.5<FA/HA<0.7, and a centroid Hc of the projected figure H coincides with a centroid Fc of the projected figure F.

Abstract: A golf club head according to this invention has scorelines formed in its face surface. A first plated layer is formed on at least the face surface of a head base body before the scorelines are formed in the face surface, the face surface is grooved to form the scorelines in it, and a second plated layer is formed on the face surface.

Abstract: This invention provides a method of manufacturing a golf club head including a face surface. This manufacturing method includes a step of forming a plurality of recessed portions in the face surface, included in a first member, to extend in the toe-to-heel direction, a fixing step of fixing, to the recessed portions, second members which are formed by a material different from that of the first member, and fill the recessed portions, and after the fixing step, a scoreline forming step of forming at least one scoreline in each of the second members, while not forming the scoreline in a portion, between the recessed portions, of the face surface of the first member.

Abstract: This invention provides a method of forming a fine groove with a width smaller than that of a scoreline in a golf club head. The method according to this invention includes a first step of forming a base groove in a face surface as a base of the fine groove, and a second step of forming a recess in at least one side wall of the base groove to reduce the angle between this side wall and the face surface.

Abstract: A putter head prevents a ball from sliding over a green while maintaining golfers' preferred hitting feel and roll of the ball. A face insert fitted in a face of the putter head has an outer layer which serves as a ball-hitting surface and an inner layer which is located on an inner side of a head body. A smash factor of a second polymer material forming the inner layer is greater than a smash factor of a first polymer material forming the outer layer. Two types of groove, grooves of a first groove group and grooves of a second groove group are formed in an external surface of the outer layer. The grooves of the first groove group may be 0.25 to 1.6 mm wide and 0.05 to 0.5 mm deep and the grooves of the second groove group may be 0.075 to 0.5 mm wide and 0.025 to 0.1 mm deep.

Abstract: A golf club head according to this invention includes a face portion, a crown portion having a shape which bulges out upward, and a sole portion. The crown portion includes a vibration promotion region and a surrounding region which surrounds the vibration promotion region. The vibration promotion region has a circular or elliptical shape, and is flatter than the surrounding region.

Abstract: This invention provides a golf club head including a face surface and sole portion. This golf club head includes a main body member, a face member, a sole member, and a fastening structure which fastens the main body member, the face member, and the sole member to be separable from each other. The main body member, the face member, and the sole member include stack portions, respectively, which are stacked on each other. The fastening structure fastens the main body member, the face member, and the sole member together in the stack portions.

Abstract: This invention provides a golf club head including a plurality of scorelines formed in its face surface and extending in the toe-to-heel direction. This golf club head includes a recessed portion for the cutting start of each scoreline, which is formed at one end or each of both ends of the scoreline in the longitudinal direction at a depth equal to or larger than that of the scoreline.

Abstract: A golf ball movement measuring apparatus includes: a camera for taking a plurality of images of a golf ball hit by a golf club; a dark-colored background material which is disposed so as to configure a background of the golf ball in the images; and a processing unit to which the images are transmitted from the camera, the processing unit masking a background portion excepting the dark-colored background material in the images in black through image processing, and the processing unit analyzing a movement of the golf ball hit by the golf club.

Abstract: This invention discloses a golf club head which has a hollow shell structure and includes a face portion, a sole portion, a crown portion, a back portion, a toe-side side portion, and a heel-side side portion. A ratio R/H×100% is 5% to 20%, where R is the radius of curvature of the upper corner edge on which the face portion and the crown portion intersect with each other, and H is the maximum head height.

Abstract: A hollow golf club head according to this invention includes a face portion, a crown portion, and a sole/side portion which includes a sole portion and a side portion. This golf club head includes a rib which extends from the toe side to the heel side in the sole portion, and a weight portion which is provided in the sole portion on the back side with respect to the rib, and increases the amplitude of vibration of the sole portion. The natural frequency of the first-order vibration mode of the sole portion is 2,500 Hz or more. A mass m (g) of the weight portion satisfies 1?m<6. The rib has a quadrangular cross-sectional shape with a width b (mm) and a height h (mm), and 0.20?b·h3/m4<8.00.