Abstract: The present invention provides a printed coil substrate for an optical disc actuator so that the sensitivity will change as little as possible when shifting in a focal direction and a tracking direction. Although the coil patterns laminated at a corresponding position have approximately same shape, center locations in shape of the tracking coil and the focus coils are displaced between the neighboring substrate layers, and the center locations in shape are displaced by a predetermined distance toward a direction of driving the movable portion driven by the coils. Even when the coil pattern of the first layer is moved in a direction of leaving from the position where magnetic force of the magnet is strong, the coil pattern of the second layer is simultaneously moved into the position where magnetic force of the magnet is strong. Therefore, the change of the sensitivity can be relatively compensated.

Abstract: The present invention provides a printed coil substrate for an optical disc actuator so that the sensitivity will change as little as possible when shifting in a focal direction and a tracking direction. Although the coil patterns laminated at a corresponding position have approximately same shape, center locations in shape of the tracking coil and the focus coils are displaced between the neighboring substrate layers, and the center locations in shape are displaced by a predetermined distance toward a direction of driving the movable portion driven by the coils. Even when the coil pattern of the first layer is moved in a direction of leaving from the position where magnetic force of the magnet is strong, the coil pattern of the second layer is simultaneously moved into the position where magnetic force of the magnet is strong. Therefore, the change of the sensitivity can be relatively compensated.

Abstract: Provided is an actuator, an optical pickup, and a disc apparatus, with improved assembling workability and reduced manufacturing cost. The actuator of the optical pickup of the disc apparatus includes a movable part and a fixed part supporting the movable part in a movable manner. The movable part includes a case and a plurality of drive substrates having the same specification. The drive substrates are disposed at positions opposed to each other with respect to the case. Each drive substrate includes a winding member for driving the movable part and a wiring pattern for supplying current to the winding member. The wiring pattern includes a plurality of electrodes and a conductive path. The electrodes are disposed at positions opposed to each other with respect to the winding member. The conductive path is branched from one end of the winding member and is connected to the electrodes.

Abstract: An objective lens actuator includes a plurality of objective lenses, a first lens holder on which the plurality of objective lenses are mounted, and a drive mechanism that drives the first lens holder. At least one of the plurality of objective lenses is mounted on the first lens holder while being held by the second lens holder. Formed on the second lens holder are a slide part which slides the second lens holder with respect to the first lens holder at a time of assembly, and a projection arranged outward of the slide part and protruding toward the first lens holder with the second lens holder being mounted on the first lens holder. The lens holder has a groove formed therein where the projection is securely adhered.

Abstract: A spherical aberration correction mechanism includes an aberration correction lens, a movable portion for supporting the aberration correction lens, a fixing portion for supporting the aberration correction lens, in which the movable portion is disposed in a slidable manner, a shaft for supporting the movable portion in a rotatable manner about the axis and in a slidable manner in the axial direction, a feed screw having a helical groove, an engaging portion having an engaging groove like a male thread engaging with the helical groove from an direction, and a coil spring engaging with the outer surface of the shaft, for pressing the movable portion in the axial direction.

Abstract: An objective lens actuator includes a lens holder, a protector holder, and a protector. The lens holder in which the objective lens is provided has a face configured to oppose the disc. The protector holder is provided on the face of the lens holder. The protector is formed with an opening defined by a first inner face, a second inner face and a bottom face between the first inner face and the second inner face. The protector has a parallelepiped shape elongating in a first direction parallel to the disc. A part of the protector is inserted in the opening so as to contact the first inner face and the second inner face and to extend from the bottom face toward the disc. A first distance between an end of the protector in a second direction in which the protector extends toward the disc and the disc is shorter than a second distance between the objective lens and the disc. A gap is formed between an end of the opening and an end of the protector in the first direction.

Abstract: A spherical aberration correction mechanism includes a plurality of aberration correction lenses, a movable portion in which the aberration correction lens is held, a fixed portion in which the movable portion is arranged so as to be slidable as well as the aberration correction lens is held, a shaft supporting the movable portion so as to be rotatable about the axis as well as to be slidable in the axial direction, a feed screw having spiral grooves, an engaging portion having convex portions to be engaged with the spiral grooves from one direction and a coil spring fitted to the outside of the shaft, pressing the movable portion in the axial direction. The coil spring has a rotation prevention portion engaged with the fixed portion and a torque biasing portion engaged with the movable portion, and the coil spring is installed in a twisted state in advance.

Abstract: A lens drive mechanism includes a drive source; a lead screw that is connected to the drive source and rotated by operation of the drive source; a nut member that screws on the lead screw and moves as the lead screw rotates; a lens hold portion that is so disposed as to move as the nut member moves and hold a lens; a guide member that guides the lens hold portion to move in the same direction as that of movement of the nut member; and a leaf spring member that if the nut member is situated near one end of a thread portion of the lead screw, pressurizes the nut member toward the other end of the thread portion of the lead screw.

Abstract: An optical pickup includes a first objective lens, a second objective lens having a numerical aperture different from that of the first objective lens, and an objective lens holder that holds the objective lenses. The first objective lens is attached to the objective lens holder via a spacer. The objective lens holder has a first fixture hole that receives the spacer with the first objective lens and a second fixture hole that receives the second objective lens. The first fixture hole is provided with a spacer supporting portion in which the spacer is inserted in a rotatable manner.

Abstract: The present invention provides an optical pickup device capable of properly suppressing coma aberration which occurs due to a relative tilt error between objective lenses. The optical pickup device includes: first and second objective lenses having different optical characteristics; a lens holder provided with first and second lens receiving cylindrical parts to which the first and second objective lenses are attached so that distance from the first objective lens to an optical recording medium becomes shorter than distance from the second objective lens to the optical recording medium without overlapping the objective lenses; and a buffer member formed in a cylindrical shape so as to surround the periphery of the first objective lens, and having a projection for preventing collision between the first objective lens and the optical recording medium, the projection being provided at an end on the optical recording medium side.

Abstract: The optical pickup includes two objective lenses, and an objective lens holder that holds the two objective lenses. The objective lens holder has two fixture holes that pass through from the lower surface to the upper surface to which the two objective lenses are attached at an upper portion with space between them. The fixture hole is provided with a fixed lens supporting portion and two movable lens supporting portions for supporting the objective lens and adjusting tilt degree thereof. The movable lens supporting portion includes a through hole that passes through to the upper portion of the fixture hole and a column member that is inserted in the through hole in a slidable manner.

Abstract: An objective lens actuator includes a lens holder, a protector holder, and a protector. The lens holder in which the objective lens is provided has a face configured to oppose the disc. The protector holder is provided on the face of the lens holder. The protector is formed with an opening defined by a first inner face, a second inner face and a bottom face between the first inner face and the second inner face. The protector has a parallelepiped shape elongating in a first direction parallel to the disc. A part of the protector is inserted in the opening so as to contact the first inner face and the second inner face and to extend from the bottom face toward the disc. A first distance between an end of the protector in a second direction in which the protector extends toward the disc and the disc is shorter than a second distance between the objective lens and the disc. A gap is formed between an end of the opening and an end of the protector in the first direction.

Abstract: A lens drive mechanism includes a drive source; a lead screw that is connected to the drive source and rotated by operation of the drive source; a nut member that screws on the lead screw and moves as the lead screw rotates; a lens hold portion that is so disposed as to move as the nut member moves and hold a lens; a guide member that guides the lens hold portion to move in the same direction as that of movement of the nut member; and a leaf spring member that if the nut member is situated near one end of a thread portion of the lead screw, pressurizes the nut member toward the other end of the thread portion of the lead screw.

Abstract: A spherical aberration correction mechanism includes an aberration correction lens, a movable portion for supporting the aberration correction lens, a fixing portion for supporting the aberration correction lens, in which the movable portion is disposed in a slidable manner, a shaft for supporting the movable portion in a rotatable manner about the axis and in a slidable manner in the axial direction, a feed screw having a helical groove, an engaging portion having an engaging groove like a male thread engaging with the helical groove from an direction, and a coil spring engaging with the outer surface of the shaft, for pressing the movable portion in the axial direction.

Abstract: A spherical aberration correction mechanism includes a plurality of aberration correction lenses, a movable portion in which the aberration correction lens is held, a fixed portion in which the movable portion is arranged so as to be slidable as well as the aberration correction lens is held, a shaft supporting the movable portion so as to be rotatable about the axis as well as to be slidable in the axial direction, a feed screw having spiral grooves, an engaging portion having convex portions to be engaged with the spiral grooves from one direction and a coil spring fitted to the outside of the shaft, pressing the movable portion in the axial direction. The coil spring has a rotation prevention portion engaged with the fixed portion and a torque biasing portion engaged with the movable portion, and the coil spring is installed in a twisted state in advance.

Abstract: An objective lens actuator includes a plurality of objective lenses, a first lens holder on which the plurality of objective lenses are mounted, and a drive mechanism that drives the first lens holder. At least one of the plurality of objective lenses is mounted on the first lens holder while being held by the second lens holder. Formed on the second lens holder are a slide part which slides the second lens holder with respect to the first lens holder at a time of assembly, and a projection arranged outward of the slide part and protruding toward the first lens holder with the second lens holder being mounted on the first lens holder. The lens holder has a groove formed therein where the projection is securely adhered.

Abstract: An optical pickup includes a first objective lens, a second objective lens having a numerical aperture different from that of the first objective lens, and an objective lens holder that holds the objective lenses. The first objective lens is attached to the objective lens holder via a spacer. The objective lens holder has a first fixture hole that receives the spacer with the first objective lens and a second fixture hole that receives the second objective lens. The first fixture hole is provided with a spacer supporting portion in which the spacer is inserted in a rotatable manner.

Abstract: The optical pickup includes two objective lenses, and an objective lens holder that holds the two objective lenses. The objective lens holder has two fixture holes that pass through from the lower surface to the upper surface to which the two objective lenses are attached at an upper portion with space between them. The fixture hole is provided with a fixed lens supporting portion and two movable lens supporting portions for supporting the objective lens and adjusting tilt degree thereof. The movable lens supporting portion includes a through hole that passes through to the upper portion of the fixture hole and a column member that is inserted in the through hole in a slidable manner.

Abstract: A first objective lens and a second objective lens which are formed as separate bodies each other are held side by side by a lens holder. The lens holder includes a first lens receiving surface to receive a lower surface of peripheral portion of the first objective lens, and a second lens receiving surface to receive a lower surface of peripheral portion of the second objective lens. The first lens receiving surface and the second lens receiving surface are formed to be coplanar. By this arrangement an optical axis of the first objective lens and an optical axis of the second objective lens become parallel to each other at the same time when the first objective lens is installed on the first lens receiving surface and when the second objective lens is installed on the second lens receiving surface, a relative tilt is automatically solved. By a simple structure of the lens holder the relative tilt between the first objective lens and the second objective lens can be reduced as above described.

Abstract: The present invention provides an optical pickup device capable of properly suppressing coma aberration which occurs due to a relative tilt error between objective lenses. The optical pickup device includes: first and second objective lenses having different optical characteristics; a lens holder provided with first and second lens receiving cylindrical parts to which the first and second objective lenses are attached so that distance from the first objective lens to an optical recording medium becomes shorter than distance from the second objective lens to the optical recording medium without overlapping the objective lenses; and a buffer member formed in a cylindrical shape so as to surround the periphery of the first objective lens, and having a projection for preventing collision between the first objective lens and the optical recording medium, the projection being provided at an end on the optical recording medium side.