摘要:
A pickup actuator capable of significantly reducing rolling of the area, including: a pickup base, a lens holder having an objective lens mounted thereon, and lens holder driving means for driving the lens holder in directions for focusing and tracking on the pickup base. The lens holder driving means includes at least one magnet, a yoke for concentrating the magnetic flux of the magnet in the direction of the magnetic flux, and a driving coil having a focusing coil and a pair of tracking coils positioned between the magnet and the yoke. The respective widths of the magnet and the yoke are set at a rate of 1:0.8-1.2. Accordingly, the uniform magnetic flux area of the magnetic flux can be widely distributed in the width's direction of the yoke. Further, the magnet is attached to one side of one yoke while being slightly lowered thereon, so that the center of the magnetic flux of the magnet is downwardly moved from its initial position to a distance corresponding to 4-12% of the height of the magnet, and the center line of the magnetic flux of the magnet and the center line of the focusing coil are aligned with each other, exactly. Further, the width of the magnet and the gap between the pair of tracking coils are set at a rate of 1:0.6-0.9. Accordingly, the portions of the pair of tracking coils intersecting the effective magnetic flux area are positioned in the area where the density of the magnetic flux is low, so that the force in the focusing direction by the tracking coils can be reduced.
摘要:
An actuator for an optical pick-up and a method of rolling a driving coil using the same. The actuator for the optical pick-up includes a bobbin for holding an object lens, a suspension for connecting the bobbin to a holder, and a magnetic driver. The magnetic driver includes a pair of permanent magnets respectively positioned near opposite sides of the bobbin, a plurality of tracking coils with pairs of the tracking coils rolled on opposite side surfaces of the bobbin, and a focus coil rolled around the bobbin and the plurality of tracking coils. The plurality of tracking coils and focus coil receive current to move the optical pickup through interaction with the permanent magnets, and a strong force is generated by narrowing a distance between the permanent magnets and the focus coil based upon the focus coil being rolled around the bobbin and the tracking coils. Accordingly, it is possible to improve the sensitivity and to prevent improper tilting of the actuator.
摘要:
An error signal detecting apparatus for an optical pickup employing a hologram grating, including a sensing lens for focusing light reflected from a recording medium, a hologram grating having first through fourth pattern regions arranged clockwise in a 2.times.2 matrix arrangement, for diffracting light incident from the sensing lens in different directions, wherein the first through fourth pattern regions a, b, c and d are formed such that a first focus of the +1st-order diffracted beams diffracted by the first and third pattern regions is relatively farther from the sensing lens than a second focus of the +1st-order diffracted beams diffracted by the second and fourth pattern regions, a photodetector disposed between the first and second focuses and having first through fourth light receiving units, for receiving the beams diffracted by the first through fourth pattern regions and independently photoelectrically converting the same, and a signal operation unit for detecting a focus error signal and/or a track error signal from detection signals of the light receiving parts. The error signal detecting apparatus can suppress generation of an offset of a focus error signal due to a change in the wavelength of a light source and an offsets of the focus error signal and track offset signal due to deviations of the photodetector.
摘要:
An optical pickup of an optical disk drive. The optical pickup includes a laser beam source for generating a laser beam; a pickup base having an objective lens for projecting the laser beam generated from the laser beam source to an information recording surface of an optical disk; a variation adjusting plate which is movably disposed on the pickup base to be moved in vertical and lateral directions, and has a rotational hole formed at a central portion thereof; and a rotation adjusting plate including a rotational section having a predetermined curvature which is inserted into the rotational hole of the variation adjusting plate, and with a laser beam source fixed therein, the rotation adjusting plate being rotated with respect to the variation adjusting plate. An optical system including a collimating lens and a reflective mirror is fixed to the pickup base. Since the light path with respect to the field angle and the beam shift is adjusted by moving and/or rotating the light emitting point of the laser beam source with respect to the light axis of the collimating lens, the size of the optical pickup becomes smaller. Further, since the collimating lens and the light source are fixed to the respective structures, the light path is controlled regardless of the focal distance of the collimating lens. Accordingly, if the focal distance of the collimating lens has to be lengthened, the beam shift and the field angle can be precisely adjusted without enlarging the optical pickup.
摘要:
An optical recording and reproducing apparatus for adjusting a tilt of an optical pickup in accordance with an amount of jitter of a reproduction signal, a tilt adjusting method therefor, and a recording control method. The optical recording and reproducing apparatus includes an optical pickup having an object lens, a tilt adjusting unit for adjusting a tilt angle of the object lens, a jitter detecting unit for detecting an amount of jitter of a reproducing signal generated by the optical pickup from a disk, and a tilt controlling unit for minimizing the amount of jitter by feeding the amount of jitter detected by the jitter detecting unit back to the tilt adjusting unit. According to the optical recording and reproducing apparatus, there is no need for a space in which a displacement sensor detecting the tilt angle of the optical pickup faces the disk.
摘要:
An optical pickup device employing a signal detection unit including a hologram element having a plurality of pattern regions for diffracting and/or focusing light reflected and incident from a recording medium, a photodetector having a plurality of light receiving regions for receiving and photoelectrically converting the light diffracted by the hologram element and a signal operation unit for generating a focus error signal and/or a track error signal from a signal detected from the photodetector. The optical pickup device can implement a stable servo operation even at deviations of the photodetector, a change in the wavelength of light emitted from the light source, and/or shift of focusing means such as an objective lens, and can record and/or reproduce high-density information on/from the recording medium.
摘要:
A light emitting module packaging two light sources emitting two light beams of different wavelengths, and a compatible optical pickup device adopting the module are provided. The light emitting module includes a base, first and second light sources installed on the base, for emitting laser beams in different wavelength regions, a beam splitter and a monitoring photodetector for monitoring the optical outputs of the first and second light sources by receiving the beams emitted from the first and second light sources and split from the beam splitter in one direction. Also, another light emitting module includes a substrate, first and second light sources installed on the substrate for emitting laser beams of first and second wavelengths from both lateral sides thereof, a reflection member for reflecting the laser beam emitted from one lateral side of each of the first and second light sources to proceed in one direction, and first and second monitoring photodetectors for monitoring optical outputs of the first and second light sources. The compatible optical pickup device includes the light emitting module having the above structure, an objective lens for focusing first and second laser beams on an optical recording medium, an optical path converting device, a grating arranged on an optical path between the light emitting module and the optical path converting device for diffracting and transmitting an incident light, a photodetector.