Abstract: A hollow golf club head enables to increase the bonding strength of an outer shell member made of metal and an outer shell member made of fiber reinforced plastic. The hollow golf club head comprises a hollow golf club having a head body of a hollow structure formed by bonding the metallic outer shell member and the fiber reinforced plastic outer shell member, wherein the fiber reinforced plastic outer shell member is bonded to both faces of the bonding portion of the metallic outer shell member.

Abstract: Disclosed is a golf club head, in which a face surface is divided into upper and lower portions by a boundary line across a position of a sweet spot thereof, a roll radius of the upper portion is set at 305 mm or less, and a roll radius of the lower portion is set at 310 mm or more.

Abstract: A golf club selecting method includes of measuring a behavior of a golf club during a golf swing performed with the golf club gripped and selecting a golf club in accordance with the golf swing. At first, a swing information for characterizing the behavior of the golf club during the golf swing performed with the golf club gripped is acquired. Then a golf club is selected in accordance with the golf swing based on the acquired swing information, wherein the acquired swing information contains a movement speed at each of a plurality of predetermined positions which are different from each other on a golf club shaft axis of the golf club, and the movement speed is a speed in an impact state immediately before a golf ball is hit with the golf club.

Abstract: A hollow golf club head enables to increase the bonding strength of an outer shell member made of metal and an outer shell member made of fiber reinforced plastic. The hollow golf club head comprises a hollow golf club having a head body of a hollow structure formed by bonding the metallic outer shell member and the fiber reinforced plastic outer shell member, wherein the fiber reinforced plastic outer shell member is bonded to both faces of the bonding portion of the metallic outer shell member.

Abstract: The golf club head (14) of the present invention has a face portion (24) for striking a golf ball, a crown portion (18) connected to the face portion (24), and a sole portion (22) connected to the face portion (24). The ratio of either lower of a first equivalent rigidity of a crown member (18) and a second equivalent rigidity of a sole member (22) to the higher is equal to or less than 0.75. The present invention provides a golf club (10) provided with the hollow golf club head (14) capable of increasing the carry of a golf ball based on a technique for increasing the carry of a golf ball other than conventional ones such as adjustment of the loft angle and reduction in the thickness of the striking surface, and provides a method of designing such a hollow golf club head as well.

Abstract: A hollow golf club head allowing to increase the repulsion and the degree of design freedom, while maintaining the durability. A hollow golf club head having a head body formed from a metal, wherein a hole is formed in the vicinity of the middle of a crown portion in the head body, the hole is closed with a cover member made of a material different from the head body, the ratio (?m/?f) of the specific gravity ?m of the head body and the specific gravity ?f of the cover member is set equal or superior to 1.3, and the ratio of the face area of a portion where the reinforcement and the head body are combined to the face area of the head body is set equal or superior to 20%.

Abstract: A hollow golf club head allowing to increase the repulsion and the degree of design freedom, while maintaining the durability. A hollow golf club head having a head body formed from a metal, wherein a hole is formed in the vicinity of the middle of a crown portion in the head body, the hole is closed with a cover member made of a material different from the head body, the ratio (?m/?f) of the specific gravity ?m of the head body and the specific gravity ?f of the cover member is set equal or superior to 1.3, and the ratio of the face area of a portion where the reinforcement and the head body are combined to the face area of the head body is set equal or superior to 20%.

Abstract: An optimal golf club shaft for a golfer is selected from among various golf club shafts, the following. At first, a head speed of a golf club at a point when the golf club strikes a golf ball during a golf swing and a downswing time amount from a top point in time when a downswing begins during the golf swing until a golf ball striking point in time are detected. Then a golf club shaft stiffness suited to the golf swing by using the head speed at the time the golf ball is struck and the downswing time amount is computed. Finally, a golf club shaft having the computed golf club shaft stiffness is selected. The golf club shaft stiffness is computed such that the optimal golf club shaft becomes stiffer as the head speed becomes higher and/or as the downswing time amount becomes longer.

Abstract: A trajectory of a struck golf ball from when the golf ball is struck until the golf ball lands is computed by a golf ball trajectory computing system. The system comprises: an initial trajectory measuring portions that measures an initial velocity, a launch angle, and a backspin rate of the golf ball immediately after impact thereof; a carry distance measuring portion that measures a carry distance of the golf ball from an impact point to a landing point where the golf ball lands; a duration-of-flight measuring portion that measures a duration of flight of the golf ball from impact thereof until the golf ball lands; and a computing portions that computes a trajectory of the golf ball based on the measured initial velocity, the measured launch angle, and the measured backspin of the golf ball immediately after impact, and the carry distance and the duration of flight of the golf ball.

Abstract: A hollow golf club head allowing to increase the repulsion and the degree of design freedom, while maintaining the durability. A hollow golf club head having a head body formed from a metal, wherein a hole is formed in the vicinity of the middle of a crown portion in the head body, the hole is closed with a cover member made of a material different from the head body, the ratio (?m/?f) of the specific gravity ?m of the head body and the specific gravity ?f of the cover member is set equal or superior to 1.3, and the ratio of the face area of a portion where the reinforcement and the head body are combined to the face area of the head body is set equal or superior to 20%.

Abstract: A hydroxygallium phthalocyanine pigment is characterized by having a maximum peak wavelength within a range of from 810 nm to 839 nm in optical absorption spectrum in a wavelength range of from 600 nm to 900 nm.

Abstract: A novel process for producing an electron source substrate is disclosed for formation of electron-emitting element at high efficiency with less shape irregularity. In the process, the region for electroconductive film formation is divided into plural subregions on which an electroconductive film is formed respectively. In forming the electroconductive film by application of plural liquids, the time interval between the application of the two drops is controlled to be larger than the time length necessary for suppressing the spreading of the succeedingly applied liquid within an allowable limit.

Abstract: A swing measurement method of directly measuring a swing behavior without being influenced by flexure of an impact implement, such as a golf club or baseball bat is provided. In addition, a golf swing analysis method and computer program product having computer program code for a simple and effective model of the behavior of a grip portion during a golf swing is provided. A three dimensional magnetic sensor capable of measuring position and direction is fixed to a grip portion of the impact implement within magnetic fields in which the magnetic field distribution of intensity and direction are known, and the behavior of the swing is directly measured. In addition, the path of the grip portion is approximated as an arc within a swing plane using the three dimensional position coordinates of the grip portion obtained in this measurement, and thus an arm angle, a wrist angle, and an angle of shaft rotation are found.

Abstract: An electrophotographic photoreceptor having, between an electroconductive substrate and a photosensitive layer, an interlayer which contains fine metal oxide particles and a binder resin and which, when an electric field of 106 V/m is applied thereto at 28° C. and 85% RH, has a volume resistivity of from 108 to 1013 &OHgr;·cm and, when an electric field of 106 V/m is applied thereto at 15° C. and 15% RH, has a volume resistivity which is up to 500 times the volume resistivity thereof as measured when an electric field of 106 V/m is applied thereto at 28° C. and 85% RH.

Abstract: A method of producing an electron-emitting device includes the steps of forming a pair of electrodes and an electrically-conductive thin film on a substrate in such a manner that the pair of electrodes are in contact with the electrically-conductive thin film and forming an electron emission region using the electrically-conductive thin film, wherein the method is characterized in that a solution containing a metal element is supplied in a droplet form onto the substrate thereby forming the electrically-conductive thin film.

Abstract: A method of producing an electron-emitting device includes the steps of forming a pair of electrodes and an electrically-conductive thin film on a substrate in such a manner that the pair of electrodes are in contact with the electrically-conductive thin film and forming an electron emission region using the electrically-conductive thin film, wherein a solution containing a metal element is supplied in a droplet form onto the substrate thereby forming the electrically-conductive thin film.

Abstract: Disclosed herein is a process for producing a printed substrate, comprising a step of applying droplets of a liquid containing a material for a desired component to be formed on a substrate to the surface of the substrate to form the component on the substrate, wherein the process comprises, prior to the step of applying the droplets to the substrate surface, a step of subjecting the substrate to a surface treatment in such a manner that the contact angle of the droplet applied with the surface of the substrate falls within a range of from 20° to 50°.

Abstract: A hollow golf club head enables to increase the bonding strength of an outer shell member made of metal and an outer shell member made of fiber reinforced plastic. The hollow golf club head comprises a hollow golf club having a head body of a hollow structure formed by bonding the metallic outer shell member and the fiber reinforced plastic outer shell member, wherein the fiber reinforced plastic outer shell member is bonded to both faces of the bonding portion of the metallic outer shell member.

Abstract: A hollow golf club head allowing to increase the repulsion and the degree of design freedom, while maintaining the durability. A hollow golf club head having a head body formed from a metal, wherein a hole is formed in the vicinity of the middle of a crown portion in the head body, the hole is closed with a cover member made of a material different from the head body, the ratio (&rgr;m/&rgr;f) of the specific gravity &rgr;m of the head body and the specific gravity &rgr;f of the cover member is set equal or superior to 1.3, and the ratio of the face area of a portion where the reinforcement and the head body are combined to the face area of the head body is set equal or superior to 20%.

Abstract: An electrophotographic photoreceptor having, between an electroconductive substrate and a photosensitive layer, an interlayer which contains fine metal oxide particles and a binder resin and which, when an electric field of 106 V/m is applied thereto at 28° C. and 85% RH, has a volume resistivity of from 108 to 1013 &OHgr;·cm and, when an electric field of 106 V/m is applied thereto at 15° C. and 15% RH, has a volume resistivity which is up to 500 times the volume resistivity thereof as measured when an electric field of 106 V/m is applied thereto at 28° C. and 85% RH.