Methods for coatings for golf balls, particularly golf balls having thermoplastic polyurethane covers, and the resulting finished balls are provided. The coating is preferably a topcoat comprising a polyurethane composition containing optical brighteners. The topcoat composition preferably comprises a low concentration of optical brighteners. For example, the concentration of optical brightener can be in the range of 0.01 to about 0.20 weight %. The optical brighteners provide the desired brightness to the golf ball without sacrificing color stability. Multi-piece golf balls having inner cores, outer cores, inner covers, and intermediate layers can be made. The finished ball with the topcoat has many advantageous physical and playing performance properties.

According to one aspect of the invention, there is provided a method for measuring ball spin, the method comprising the steps of: detecting information on a mark appearing in a region corresponding to a ball hit by a user in each of a plurality of images in which the ball is photographed; determining whether it is possible to directly calculate physical quantities related to spin of the ball on the basis of the information on the mark; and when it is determined that it is not possible to directly calculate the physical quantities related to spin of the ball on the basis of the information on the mark, estimating the physical quantities related to spin of the ball on the basis of physical quantities related to at least one of a speed and an angle of the ball or a club hitting the ball.

Provided are a golf ball and a resin composition for a cover or topcoat thereof which can suppress the yellowing of the golf ball caused by ultraviolet rays even if a naturally derived substance is used as an ultraviolet absorber, and they are environmentally and human friendly. A resin composition for a cover or topcoat of a golf ball of the present invention contains: a resin for a cover or topcoat; and a plant-derived extract which absorbs ultraviolet rays. The resin composition has a color difference ΔE of 10.0 or less in a Lab color system between before and after a color tone change test, the color tone change test being carried out by irradiating a film formed from the resin composition with a xenon lamp. In the golf ball of the present invention, the cover or the topcoat is formed by using the resin composition.

A golf ball comprising an electrical component is disclosed herein. The electrical component comprises an integrated circuit having a gyroscope, a magnetometer, and a BLUETOOTH low energy (BTLE) radio, and at least one battery. A body is composed of an epoxy material, and the body encompasses the electrical component.

A golf ball comprising an integrated circuit is disclosed herein. The integrated circuit comprises a gyroscope, a magnetometer, and a BLUETOOTH low energy (BTLE) radio, and at least one battery. A body is composed of an epoxy material, and the body encompasses the integrated circuit. A wound core layer is disposed over the body.

Golf balls including one or more layers having at least one radar detectable mark disposed on the surface thereof are provided.

Golf balls including one or more layers having at least one radar detectable mark disposed on the surface thereof are provided.

Golf balls including one or more layers having at least one radar detectable mark disposed on the surface thereof are provided.

Golf balls including one or more layers having at least one radar detectable mark disposed on the surface thereof are provided.

A sports ball is configured to enhance detection of spin properties by radar. The ball includes a spherical body having a first reflectivity with respect to radiation generated by a radar to be used in detecting spin of the ball. In addition, the ball includes a plurality of markers. Each of the markers has a second reflectivity with respect to the radiation generated by a radar to be used in detecting spin of the ball. The second reflectivity is different from the first reflectivity. The markers are distributed on the ball so that every great circle extending around an exterior surface of the ball is within a distance d of a projection on the exterior surface of the ball of at least one of the markers. The distance d is less than a radius of the ball.