Abstract: The present invention relates to a half-pel motion estimation method. The calculation object half-pel, which is in the block of the previous or next reference frame, is not estimated additionally for each block of the current frame divided into blocks of a predetermined size. The present invention suggests an algorithm that can perform half-pel search only with a SAD value used in integer-pel search and a random variable for correcting errors. Since the present invention does not have to generate half-pel for motion estimation, the calculation amount is amazingly reduced and the calculation time is reduced.

Abstract: A fast block mode determining method for motion estimation, and an apparatus thereof. A cost of motion estimation for an input image frame is predicted by Kalman filtering, and one block mode is selected from a plurality of block modes. A cost for the motion estimation of the input image frame is calculated. The predicted cost and the calculated cost are compared with each other, and the block mode for performing the motion estimation is determined. In an H.264 moving picture encoding device, the operation load is reduced and time wasted for calculation is shortened, because it is not necessary to perform the motion estimation for all the block modes.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An optical pickup assembly includes a base, a bobbin having an objective lens mounted thereon, the bobbin being installed at the base so as to be movable and having a pair of first side surfaces parallel to a radial direction of a disk and a pair of second side surfaces parallel to the tangential direction of a disk track, a focus coil wound around the bobbin for driving the objective lens in a focus direction, a track coil installed at the first side surfaces for driving the objective lens in a radial direction of the disk, a driving magnet installed at the base to face the first side surfaces, a tilt coil installed at the second side surfaces for driving the objective lens in response to the relative inclination between the objective lens and the disk, a first tilt magnet installed at the base such that one polarity thereof faces the tilt coil, a second tilt magnet installed at an upper portion of the first tilt magnet such that another polarity opposite to the one polarity thereof faces the tilt coil, an i

Abstract: 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.

Abstract: 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 pick-up 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.

Abstract: 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.

Abstract: An optical pickup includes a variable iris having a numerical aperture is adjusted according to wavelength of light and can be compatibly used for discs having respectively different specifications.

Abstract: 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.