1. A golf club comprising:
a face portion disposed on the front face of a metallic hollow golf club head and having a hitting surface for hitting a golf ball;
a sole portion which forms the lower portion of said metallic hollow golf club head; and
a crown portion which forms the upper portion of said metallic hollow golf club head;
wherein said sole portion comprises;
a deformation portion disposed on said sole portion which is capable of elastic deformation when a golf ball is struck;
wherein said deformation portion includes;
a protruding part which protrudes such that said sole portion is formed in an obtuse angle, in continuation with said hitting surface and said face portion, as viewed in a cross section cut along a vertical plane including a perpendicular to said hitting surface in order to enhance an elastic effect;
said protruding part have a first corner in said obtuse angle linking said face portion and said sole portion, and a second corner in said sole portion.
2. The golf club according to claim 1, wherein said deformation portion comprises at least one convex portion formed in the direction linking the toe portion and the heel portion by a protrusion protruding towards said crown portion.
3. The golf club according to claim 2, wherein said deformation portion is disposed on the side of said face portion.
4. The golf club according to claim 1, wherein said protruding part comprises at least one concave groove formed in the direction linking the toe portion and the heel portion by a protrusion protruding towards said crown portion.
5. The golf club according to claim 4, wherein said concave groove is disposed on the side of said face portion.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A differential amplifier comprising:
a pair of first emitter-follower transistors for buffering input signals;
a pair of voltage drop generation circuits for generating voltage drops dependent upon collector currents at the collectors of the first emitter-follower transistors;
a pair of second emitter-follower transistor for buffering output signals of the first emitter-follower transistors;
a pair of first amplification transistors which are alternately connected with the first emitter-follower transistors and are driven by the second emitter-follower transistors;
a pair of second amplification transistors which are driven by the second emitter-follower transistors, thus providing output signals;
a pair of first base-grounded transistors which are inserted between the first emitter-follower transistors and the first amplification transistors;
a pair of second base-grounded transistors which are inserted between the second amplification transistors and output terminals; and
a bias circuit for supplying each of the first base-grounded transistors and the second base-grounded transistors with a bias voltage, thus setting a same collector-emitter voltage to each of the first emitter-follower transistors and each of the first amplification transistors and the second amplification transistors.
2. A differential amplifier according to claim 1 further comprising a voltage shift circuit in connection with the second emitter-follower transistors, the first amplification transistors, and the second amplification transistors.
3. A differential amplifier according to claim 2, wherein the bias circuit is constituted of a constant current source and a series circuit which is constituted of a bias transistor whose collector and base are connected together, a second voltage drop circuit for generating a voltage drop dependent upon a collector current of the bias transistor, and a second voltage shift circuit, and wherein the bias voltage is output from a connection point between the series circuit and the constant current source.
4. A differential amplifier according to claim 1 further comprising a pair of third emitter-follower transistors whose emitters are connected to the collectors of the second emitter-follower transistors, wherein the voltage drop generation circuits are constituted of a pair of first collector resistors, which are connected to the collectors of the first emitter-follower transistors, and a pair of second collector resistors, which are connected to the first collector resistors in series, and wherein bases of the third emitter-follower transistors are connected to connection points between the first collector resistors and the second collector resistors.
5. A differential amplifier according to claim 1 further comprising a plurality of output circuits, which are connected in parallel and one of which is constituted of the second amplification transistors and the second base-grounded transistors as well as emitter resistors and a constant current source.
6. A differential amplifier comprising:
a pair of first emitter-follower transistors for receiving input signals at bases thereof;
a pair of voltage drop generation circuits for generating voltage drops dependent upon collector currents at the collectors of the first emitter-follower transistors;
a pair of second emitter-follower transistors which are connected with the first emitter-follower transistors;
a pair of first amplification transistors whose bases are alternately connected to emitters of the second emitter-follower transistors and whose collectors are connected to emitters of the first emitter-follower transistors;
a pair of second amplification transistors whose bases are connected to the bases of the first amplification transistors, thus providing output signals;
a pair of first base-grounded transistors inserted between the emitters of the first emitter-follower transistors and the collectors of the first amplification transistors;
a pair of second base-grounded transistors which are connected to collectors of the second amplification transistors; and
a bias circuit for supplying each of the first base-grounded transistors and the second base-grounded transistors with a bias voltage, thus setting a same collector-emitter voltage to each of the first emitter-follower transistors, each of the first amplification transistors, and each of the second amplification transistors.
7. A differential amplifier according to claim 6 further comprising a voltage shift circuit in connection with the second emitter-follower transistors, the first amplification transistors, and the second amplification transistors.
8. A differential amplifier according to claim 7, wherein the bias circuit is constituted of a constant current source and a series circuit which is constituted of a bias transistor whose collector and base are connected together, a second voltage drop circuit for generating a voltage drop dependent upon a collector current of the bias transistor, and a second voltage shift circuit, and wherein the bias voltage is output from a connection point between the series circuit and the constant current source.
9. A differential amplifier according to claim 6 further comprising a pair of third emitter-follower transistors whose emitters are connected to the collectors of the second emitter-follower transistors, wherein the voltage drop generation circuits are constituted of a pair of first collector resistors, which are connected to the collectors of the first emitter-follower transistors, and a pair of second collector resistors, which are connected to the first collector resistors in series, and wherein bases of the third emitter-follower transistors are connected to connection points between the first collector resistors and the second collector resistors.
10. A differential amplifier according to claim 6 further comprising a plurality of output circuits, which are connected in parallel and one of which is constituted of the second amplification transistors and the second base-grounded transistors as well as emitter resistors and a constant current source.