Abstract:
A slim optical pickup apparatus which records/reads information from a recording medium includes a light source, an objective lens which focuses a beam incident from the light source on the recording medium, an optical device which is provided on an optical path between the light source and the objective lens, and converts the beam incident from the light source into a parallel beam, an optical axis shifting unit which is provided on an optical path between the optical device and the objective lens, and shifts an optical axis of the parallel beam passing through the optical device in parallel in a direction, a reflecting mirror which is provided on an optical path between the optical axis shifting unit and the objective lens, and reflects the parallel beam passing through the optical axis shifting unit toward the recording medium, and a photodetector which receives a beam reflected from the recording medium and passed through the optical axis shifting unit, and performs a photoelectric conversion. Use of the optical path shifting unit reduces the height of an optical pickup apparatus, thereby providing a slim optical pickup apparatus using an existing light source and photodetector of a conventional size.
Abstract:
A magnetic circuit, an optical pickup actuator, an optical recording and/or reproducing apparatus using the magnetic circuit, and method of the same, wherein the magnetic circuit includes a plurality of focus coil units each of which includes a first focus coil and a second focus coil, and a magnet including a plurality of magnet portions which interact with the plurality of focus coil units and each of which is polarized in a direction opposite to adjacent magnet portions thereamong. Here, electromagnetic forces act on the first and second focus coils in each focus coil unit in a same direction in response to focus driving signals and in opposite directions in response to tilt driving signals, with the first and second focus coils in each focus coil unit have different effective coil lengths.
Abstract:
An optical pickup which, when a first light reflected by a recording medium is divided into a central light area and first and second peripheral light areas at both sides of the central light area, divides the first light reflected by the recording medium into at least 6 light areas, and the at least 6 light areas are independently detected from first through sixth light-receiving portions of a photodetector. Hence, the photodetector can detect a tracking error signal whose offset generation due to a shift of an objective lens is insensitive and whose offset generation due to an initial photodetector balance deviation is depressed.
Abstract:
An optical pickup apparatus includes a first light source to emit a first light beam having a predetermined wavelength, a first optical path changer to change a proceeding path of the first light beam, an objective lens to focus the first light beam on a recording medium, a diffraction member to divide the first light beam reflected by the recording medium into five light regions, the diffraction member having a first diffraction region having a wide width in a direction corresponding to a tangential direction of the recording medium and second through fifth diffraction regions sequentially arranged around the outside of the first diffraction region in a direction corresponding to a radial direction of the recording medium, and a first photodetector having first through fifth light receiving portions to receive the first light beam reflected by the recording medium.
Abstract:
An optical pickup for a recording medium includes a light source, an objective lens, a main photodetector, and a front photodetector. The configuration of the optical pickup enables converging or diverging of light to be incident on a plate beam splitter so that light can be received at an effective light receiving region of a front photodetector without interference due to internal reflection occurring in the plate beam splitter. In the alternative, a wedge beam splitter in the optical pickup includes first and second mirror planes at a predetermined angle to transmit and reflect incident light at a predetermined ratio. In the optical pickup, an amount of light that is exactly proportional to an output power of the light source can be detected, where the output power of the light source can be accurately controlled, thereby improving a linearity of the output power of the light source.
Abstract:
A method and an apparatus for identifying the type of an optical recording medium are provided. The method includes detecting a surface reflected signal SS and a writable-surface reflected signal SR of an optical recording medium while performing a focus search using a first optical system, counting a time difference DTS between a high peak and a low peak of the surface reflected signal SS, counting a time difference DTR between the high peak of the surface reflected signal and a high peak of the writable-surface reflected signal SR, obtaining DT by substituting DTR and DTS into the following equation: DT = ( DT R ) a ( DT S ) b ( a - b ≥ 1 2 ) and comparing DT with a reference time T, and driving the first optical system if DT is greater than T and driving a second optical system if DT is not greater than T.
Abstract translation:提供了一种用于识别光学记录介质的类型的方法和装置。 该方法包括在使用第一光学系统执行聚焦搜索的同时检测光学记录介质的表面反射信号S S S S和可写表面反射信号S SUB S R S,计数 在表面反射信号S S S的高峰值和低峰值之间的时差DT S S / S,计数在表面反射信号S S S上的时间差DT< S< 表面反射信号的高峰值和可写表面反射信号S的高峰值,通过用DT< R>和DT< S>和< >进入以下公式:
Abstract:
An apparatus and method for detecting beam power generated by a plurality of light sources, using a single device. The apparatus includes a light-receiving unit that receives the beam power generated by one of a plurality of light sources, and an amplifying unit that selects a gain, amplifies the beam power received by the light-receiving unit according to the selected gain, and outputs the beam power amplified as a detected beam power. According to the apparatus and method, received beam power (or amplification gain) is amplified by a gain determined according to the characteristics of the respective light sources. Thus, it is possible to provide the detected beam power in consideration of a sufficient dynamic range for the each light source, thereby realizing effective APC.
Abstract:
A magnetic circuit and an optical recording and/or reproducing apparatus employing the magnetic circuit, having: a magnet with first and second magnetic portions adjacent to each other and opposite in polarity, and third and fourth magnetic portions surrounding the first and second magnetic portions, respectively, and have opposite polarities to the first and second magnetic portions, respectively; and at least one of a tracking coil unit or a focus coil unit. The tracking coil unit has first through third tracking coils arranged in a tracking direction so that each tracking coil interacts with two of the first through fourth magnetic portions. The focus coil unit has first through fourth focus coils, two of which are disposed in a focus direction to interact with the first and third magnetic portions, and the remaining two of which are disposed in the focus direction to interact with second and fourth magnetic portions.
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.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.
Abstract:
An optical pickup, photodetector, and optical drive adopting the optical pickup are provided. The optical pickup may include a light emitting system having a plurality of light sources corresponding to a plurality of mediums a light receiving system including a photodetector for converting light reflected from a medium into an electrical signal. The photodetector may include first and second light receiving sensors corresponding to the plurality of mediums, each of the first and second light receiving sensors comprising a plurality of regions, each region comprising a plurality of sectors. The plurality of regions of the first and second light receiving sensors may include shared sectors that are shared by the first and second light receiving sensors and exclusive sectors that are exclusively used in the first light receiving sensor or the second light receiving sensor.