Abstract: This method simulates a run which is a distance between a landing point and a final arriving point using an initial condition of a hit ball and an actually measured falling condition. Preferably, the initial condition includes initial side spin. Preferably, the falling condition is a falling velocity. Preferably, a calculation formula of the run is a quadratic function having the initial condition and the falling condition as variables.

Abstract: A head 2 includes a head body h1 and a neck part n1. The head body h1 and the neck part n1 are joined. The head body h1 has a body side joint surface s1 and a first recessed part opened in the body side joint surface s1. A space v1 is formed by the first recessed part r1. The neck part n1 has a neck side joint surface brought into surface contact with the body side joint surface s1 and a shaft hole 14. An abutted boundary surface Pt passes through a vicinity ad1 of a head height lowest point. When a plane perpendicular to an axis line z of the shaft hole 14 is defined as PL, and an angle between the plane PL and the abutted boundary surface Pt is ? degree, the angle ? is a plus value.

Abstract: A golf club head of the present invention includes a face. The face has a score line groove, a fine groove, and a land area. A depth of the fine groove is 0.01 mm or greater and less than 0.03 mm. A width of the fine groove is 0.1 mm or greater and 0.3 mm or less. A pitch of the fine groove is 0.3 mm or greater and 0.7 mm or less. Preferably, the face further has a protruding part protruding beyond the land area. Preferably, the protruding part is provided on a top blade side of the fine groove. Preferably, the protruding part extends along the fine groove.

Abstract: A hollow golf club head comprises a face portion with a face for hitting a ball on its front and a crown portion forming a top surface of the head, wherein the head comprises a face member including the face portion and made of a metallic material and a crown member attached to the face member to form the crown portion at least partially, the crown member includes a first member made of a metal material and a second member made of a fiber reinforced resin for supporting the first member so that the first member does not directly contact with the face member, the head has a primary natural frequency of from 3800 to 6500 Hz and an antinode when the head vibrates in the primary natural mode appears in the first member.

Abstract: An object of the present is to provide a golf ball having an increased spin rate on approach shots. Another object of the present invention is to provide a golf ball having a goof shot feeling on approach shots. The present invention provides a golf ball comprising a golf ball body and a paint film formed on a surface of the golf ball body, and having a coefficient of friction calculated using a contact force tester of 0.35 or more and 0.60 or less.

Abstract: Golf ball 2 has a spherical core 4, a mid layer 6 covering this core 4, a reinforcing layer 8 covering this mid layer 6, and a cover 10 covering this reinforcing layer 8. Base polymer of the mid layer 6 includes an ionomer resin as a principal component. The mid layer 6 has a hardness Hm as measured with a Shore D type hardness scale of equal to or greater than 55. Base polymer of the reinforcing layer 8 is a thermosetting resin. Base polymer of the cover 10 includes a thermoplastic polyurethane elastomer as a principal component. The cover 10 has a thickness Tc of equal to or less than 0.6 mm. The cover has a hardness Hc as measured with a Shore D type hardness scale of equal to or less than 54. Ratio (Tr/Tc) of the thickness Tr of the reinforcing layer to the thickness Tc of the cover is 0.005 or greater and 3.0 or less.

Abstract: A measuring apparatus 10 for a golf club 34 includes: a club camera 20 capable of photographing the golf club; a control part 30 capable of controlling a timing at which the golf club is photographed; and three sensors capable of detecting passage of the golf club 34. The three sensors are defined as a first sensor S1, a second sensor S2, and a third sensor S3 in this order from a point close to a position of a golf ball. When a club speed calculated based on the passage of the golf club detected by the second sensor S2 and the third sensor S3 is equal to or greater than a predetermined threshold value, the control part generates a trigger signal for starting to photograph the golf club. The measuring apparatus 10 can effectively suppress erroneous generation of the trigger signal.

Abstract: A golf ball 2 has a large number of dimples 10 on a surface thereof. The golf ball 2 meets the following mathematical formula (I): Y?3.8*X?2.894 ??(I), where X represents a ratio of a sum of areas of all the dimples 10 to a surface area of a phantom sphere of the golf ball, and Y represents a standard deviation (mm) of diameters of all the dimples 10.

Abstract: A golf ball 2 includes a core 4 and a cover 6 that is composed of an inner cover 8 and an outer cover 10. The core 4 has a radius of R (mm). A hardness Hs at a surface of the core 4 is greater than a hardness HL(R) when a linear approximation curve obtained by plotting a midpoint of each layer of the cover 6 in a thickness direction thereof in a graph in which a horizontal axis indicates a distance (mm) from a central point of the core 4 and a vertical axis indicates a hardness is represented by the following mathematical formula (I): HL(X)=A*X+B??(I), where X represents a distance (mm) from the central point of the core 4, HL(X) represents a hardness, and A and B represent a gradient and an intercept, respectively, of the linear approximation curve.

Abstract: A method and system for correcting a silhouette of a person extracted from an image by labeling each pixel as the person or the background are disclosed. The pixels in a target region are corrected by: a step in which, by the use of pixels in the target region labeled as the person, a person histogram is created; a step in which, by the use of pixels in the target region labeled as the background, a background histogram is created; a step in which, for each pixel in the target region, by the use of the person histogram, the background histogram and color data of each pixel in the target region, first connective costs of the pixel to the color data of the person and the background are calculated; and a step in which, for each pixel in the target region, a second connective cost of the pixel is calculated.

Abstract: A golf club shaft has a tip end to which a golf club head is attached and a butt end to which a grip is attached, wherein the shaft is composed of a fiber reinforced resin having a fiber layer, the fiber layer contains a bias layer having bias fibers oriented at an angle with respect to an axial direction of the shaft, the bias layer includes a tip-side bias layer extending from the tip end toward the butt end and having a butt-side end terminating without reaching the butt end and a butt-side bias layer extending from the butt end toward the tip end and having a tip-side end terminating without reaching the tip end, and bias fibers in the tip-side bias layer has a tensile elastic modulus smaller than that of bias fibers of the butt-side bias layer.

Abstract: A multi-piece golf ball includes a core composed of a center, an envelope layer and at least one cover. The center is formed from a composition containing at least one resin component and a basic metal salt of a fatty acid. The resin component is selected from a binary copolymer composed of an olefin and an ?,?-unsaturated carboxylic acid, an ionomer resin consisting of a metal ion-neutralized product of a binary copolymer composed of an olefin and an ?,?-unsaturated carboxylic acid, a ternary copolymer composed of an olefin, an ?,?-unsaturated carboxylic acid and an ?,?-unsaturated carboxylic acid ester, and an ionomer resin consisting of a metal ion-neutralized product of a ternary copolymer composed of an olefin, an ?,?-unsaturated carboxylic acid and an ?,?-unsaturated carboxylic acid ester. The envelope layer is formed from a composition containing a thermoplastic resin and/or a thermoplastic elastomer as a resin component.

Abstract: A section where the tip side partial bias layer exists in an axis direction of the shaft is defined as a section T; a section where the back end side partial bias layer exists in the axis direction of the shaft is defined as a section B; and a shaft section inserted into a hosel of a head in the axis direction of the shaft is defined as a section H. A part of the section T overlaps with the section H. An overlapping section TB in which the section T overlaps with the section B exists. The whole overlapping section TB is located on a back end Bt side of the shaft from the section H. A center position Px of the overlapping section TB is located on a tip side of the shaft from a center position Pc of the shaft.

Abstract: It is an object to provide a tubular body made from a novel fiber-reinforced epoxy resin material having improved strength. A tubular body made of a fiber-reinforced epoxy resin material according to the present invention is a tubular body made of a fiber-reinforced epoxy resin material comprising a cured product of an epoxy resin composition and a reinforcing fiber. The cured product of the epoxy resin composition has a swelling ratio of 20% by mass to 42.5% by mass in methyl ethyl ketone.

Abstract: A multi-piece golf ball excellent in resilience and controllability includes a core composed of a center and an envelope layer covering the center and at least one cover covering the core, wherein the center is formed from a center composition containing (A) at least one resin component selected from the group consisting of (a-1) a binary copolymer composed of an olefin and an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms, (a-2) an ionomer resin consisting of a metal ion-neutralized product of the binary copolymer, (a-3) a ternary copolymer composed of the binary copolymer components and an ?,?-unsaturated carboxylic acid ester, and (a-4) an ionomer resin consisting of a metal ion-neutralized product of the ternary copolymer components and (B) a basic metal salt of a fatty acid, and wherein the envelope layer is formed from a rubber composition.

Abstract: An object of the present invention is to provide a golf ball excellent in a shot feeling and resilience. The present invention provides a golf ball resin composition comprising (A) at least one resin component selected from the group consisting of (a-1) a binary copolymer composed of an olefin and an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms, (a-2) an ionomer resin consisting of a metal ion-neutralized product of the binary copolymer, (a-3) a ternary copolymer composed of the binary copolymer components and an ?,?-unsaturated carboxylic acid ester, and (a-4) an ionomer resin consisting of a metal ion-neutralized product of the ternary copolymer components; and (B) a basic metal salt of a fatty acid, and having a spin-lattice relaxation time (T1) of 13C nucleus of 5.56 seconds or shorter measured by a High resolution solid state nuclear magnetic resonance (NMR) method.

Abstract: A set of iron-type golf clubs and a set of iron-type golf club heads are disclosed. The loft angles of the heads are gradually increased from the lowest numbered golf club to the highest numbered golf club in the set. Given that a coefficient of inertia of the head is the ratio Ms/M of a moment of inertia Ms (gram sq·cm) of the head around a horizontal axis extending in a toe-heel direction of the head passing through the center of gravity of the head, to the mass M (g) of the head, the coefficient of inertia is gradually increased with the increase in the loft angle, and the difference of the coefficient of inertia of the head of the highest numbered club from that of the lowest numbered club is 0.3 or more.

Abstract: An object of the present invention is to provide a golf ball having a low spin rate on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) base rubber, (b) an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof as a co-crosslinking agent, (c) a crosslinking initiator and (d) a carboxylic acid having a benzene ring and/or a salt thereof, provided that the rubber composition further contains (e) a metal compound in case of containing only (b) the ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms as the co-crosslinking agent.

Abstract: A golf ball resin composition that is excellent in resilience includes (A) at least one resin component selected from the group consisting of (a-1) a binary copolymer composed of an olefin and an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms, (a-2) an ionomer resin consisting of a metal ion-neutralized product of a binary copolymer composed of an olefin and an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms, (a-3) a ternary copolymer composed of an olefin, an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and an ?,?-unsaturated carboxylic acid ester, and (a-4) an ionomer resin consisting of a metal ion-neutralized product of a ternary copolymer composed of an olefin, an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms and an ?,?-unsaturated carboxylic acid ester, and (B) a basic metal salt of a fatty acid.

Abstract: An object of the present invention is to provide a golf ball resin composition excellent in shot feeling and resilience. The golf ball resin composition includes (A) at least one resin component selected from the group consisting of (a-1) a binary copolymer composed of an olefin and an ?,?-unsaturated carboxylic acid having 3 to 8 carbon atoms, (a-2) an ionomer resin consisting of a metal ion-neutralized product of the binary copolymer components, (a-3) a ternary copolymer composed of the binary copolymer components and an ?,?-unsaturated carboxylic acid ester, and (a-4) an ionomer resin consisting of a metal ion-neutralized product of the ternary copolymer components; and (B) a basic metal salt of a fatty acid, and having a storage modulus E? (Pa) and a loss modulus E? (Pa) satisfying a following expression; log(E?/E?2)??5.84 when measured in a tensile mode using a dynamic viscoelasticity measuring apparatus.