Abstract: An optical disc drive 1 includes a spindle motor 11 for rotating the optical disc 2 and a spindle driver for driving the spindle motor 11 equipped with a rotation number counter 232 for measuring the rotation number of the spindle motor 11. A brake for braking the spindle motor 11 to reduce the rotation number thereof, can include at least three types of brake modes, and a selector for selecting one of the types of brake modes in response to the rotation number measured by the rotation number counter 232 when the rotation number of the spindle motor 11 is to be reduced. The optical disc drive 1 may further include a judging circuit for judging whether the rotation number of spindle motor 11 measured by the rotation number counter 232 reaches a predetermined target rotation number when the rotation of the optical disc 2 is to be stopped by the spindle motor 11.

Abstract: A liquid delivery pump includes a pump room for transferring liquid, a plunger having one end located in the pump room for moving reciprocally therein for delivering the liquid in the pump room, and a base end, and a crosshead for reciprocal movement situated adjacent to the pump room and having a flat end surface. A ball is attached to the crosshead to contact the flat end surface thereof. The base end is attached to the crosshead so that the plunger rotates freely relative to the flat end surface through the ball.

Abstract: Three metal plate materials, each having penetration holes, are united together in this order as a set at such positions that penetration holes can penetrate through the three metal plate materials so as to form a mixing portion. A plurality of sets, each having the mixing portion, are integrated together at such positions that all of the penetration holes can penetrate through the respective sets of plate materials. The mixing portions of the respective sets are connected in parallel to one another.

Abstract: An optical disc drive 1 of the present invention includes a spindle motor 11 for rotating the optical disc 2, a spindle driver for driving the spindle motor 11 equipped with rotation number measuring means 232 for measuring the rotation number of the spindle motor 11, brake means for braking the spindle motor 11 to reduce the rotation number thereof, which includes at least three types of brake modes, and selecting means for selecting one of the at least three types of brake modes in response to the rotation number measured by the rotation number measuring means 232 when the rotation number of the spindle motor 11 is to be reduced. The optical disc drive 1 may further includes judging means for judging whether the rotation number of spindle motor 11 measured by the rotation number measuring means 232 reaches a predetermined target rotation number when the rotation of the optical disc 2 is to be stopped by the spindle motor 11.

Abstract: Three metal plate materials, each having penetration holes, are united together in this order as a set at such positions that penetration holes can penetrate through the three metal plate materials so as to form a mixing portion. A plurality of sets, each having the mixing portion, are integrated together at such positions that all of the penetration holes can penetrate through the respective sets of plate materials. The mixing portions of the respective sets are connected in parallel to one another.