Mechanism for minute movement of a head

A mechanism for minute movement of a head for use in a disk rive including at least one recording disk, a head provided for each information recording surface of the recording disk so as to carry out an information reading/writing operation, and a head actuator for moving the head in a radial direction of the recording disk so as to position the head at a desired recording track on the recording disk, the mechanism for minute movement of the head provided at a part of the head actuator and constructed such that the head can be moved only a small distance independently of an operation of the head actuator, comprising:

• at least one pair of expansion and contraction members;
• driving means for applying power to said at least one pair of expansion and contraction members;
• and
• a coupling plate having continuous top and bottom surfaces including a fixed region, a movable region, at least one hinge portion and at least one expansion and contraction region,
• said at least one expansion and contraction region defined as being an indentation in part of at least one of said top and bottom surfaces of the coupling plate in such a manner that said part of said top and bottom surfaces of the coupling plate can be displaced, said expansion and contraction region having top and bottom surfaces corresponding to said top and bottom surfaces of said coupling plate and having first and second end surfaces,
• said at least one pair of expansion and contraction members is fixed within the indentation on both said top and bottom surfaces of the at least one expansion and contraction region sandwiching said at least one expansion and contraction region therebetween and said expansion and contraction members cause the expansion and contraction region to expand or contract within a plane parallel to the moving plane of the head by deformation of said at least one pair of expansion and contraction members generated according to application of power thereto,
• said fixed region is provided continuously with said first end surface of the at least one expansion and contraction region, said fixed region is not displaced according to the expansion or contraction of the at least one expansion and contraction region,
• said movable region is provided continuously with the second end surface of the at least one expansion and contraction region in an expanding direction thereof, and said movable region is displaced according to expansion or contraction of the at least one expansion and contraction region, and
• said at least one hinge portion is formed between the fixed region and the movable region or between the movable region and the at least one expansion and contraction region and displaces the movable region smoothly within the moving plane of the head.

A mechanism for minute movement of a head for use in a disk drive including at least one recording disk, a head provided for each information recording surface of the recording disk so as to carry out an information reading/writing operation, and a head actuator for moving the head in a radial direction of the recording disk so as to position the head at a desired recording track on the recording disk, the mechanism for minute movement of the head provided at a part of the head actuator and constructed such that the head can be moved only a small distance independently of an operation of the head actuator, comprising:

• at least one pair of expansion and contraction members;
• driving means for applying power to said at least one pair of expansion and contraction members;
• and
• a coupling plate having continuous top and bottom surfaces including a fixed region, a movable region, hinge portions and at least one expansion and contraction region,
• said at least one expansion and contraction region defined as being part of at least one of said top and bottom surfaces of the coupling plate in such a manner that said part of said top and bottom surfaces of the coupling plate can be displaced, said expansion and contraction region having top and bottom surfaces corresponding to said top and bottom surfaces of said coupling plate and having first and second end surfaces,
• said at least one pair of expansion and contraction members is fixed onto both said top and bottom surfaces of the at least one expansion and contraction region sandwiching said at least one expansion and contraction region therebetween and said expansion and contraction members cause the expansion and contraction region to expand or contract within a plane parallel to the moving plane of the head by deformation of said at least one pair of expansion and contraction members generated according to application of power thereto,
• said fixed region is provided continuously with said first end surface of the at least one expansion and contraction region, said fixed region is not displaced according to the expansion or contraction of the at least one expansion and contraction region,
• said movable region is provided continuously with the second end surface of the at least one expansion and contraction region in an expanding direction thereof, and said movable region is displaced according to expansion or contraction of the at least one expansion and contraction region, and
• said hinge portions are formed between the fixed region and the movable region or between the movable region and the at least one expansion and contraction region and said hinge portions displace the movable region smoothly within the moving plane of the head, wherein hinge portions include a center hinge and side hinge portions each provided on opposite sides of the center line and wherein a line connecting the center hinge and each of the side hinge portions is not perpendicular to the center line.

A mechanism for minute movement of a head for use in a disk drive including at least one recording disk, a head provided for each information recording surface of the recording disk so as to carry out an information reading/writing operation, and a head actuator for moving the head in a radial direction of the recording disk so as to position the head at a desired recording track on the recording disk, the mechanism for minute movement of the head provided at a part of the head actuator and constructed such that the head can be moved only a small distance independently of an operation of the head actuator, comprising:

• at least one pair of expansion and contraction members each having a solid plate shape;
• driving means for applying power to said at least one pair of expansion and contraction members;
• and
• a coupling plate having continuous top and bottom surfaces which are parallel to a moving plane of the head, said continuous top and bottom surfaces including a fixed region, a movable region, at least one hinge portion and at least one expansion and contraction region,
• said at least one expansion and contraction region defined as being made of a solid material and as being part of at least one of said top and bottom surfaces of the coupling plate in such a manner that said part of said top and bottom surfaces of the coupling plate can be displaced, said expansion and contraction region having top and bottom surfaces corresponding to said top and bottom surfaces of said coupling plate and having first and second end surfaces and wherein an expansion and contraction force is not generated by said at least one expansion and contraction region,
• said at least one pair of expansion and contraction members is fixed on top of both said top and bottom surfaces of the at least one expansion and contraction region sandwiching at least one expansion and contraction region therebetween and said expansion and contraction members cause the expansion and contraction region to expand or contract within a plane parallel to the moving plane of the head by deformation of said at least one pair of expansion and contraction members generated according to application of power thereto,
• said fixed region is provided continuously with said first end surface of the at least one expansion and contraction region, said fixed region is not displaced according to the expansion or contraction of the at least one expansion and contraction region,
• said movable region is provided continuously with the second end surface of the at least one expansion and contraction region in an expanding direction thereof, and said movable region is displaced according to expansion or contraction of the at least one expansion and contraction region, and
• said at least one hinge portion is formed between the fixed region and the movable region or between the movable region and the at least one expansion and contraction region and displaces the movable region smoothly within the moving plane of the head.