Abstract: A write power adjustment method makes it possible to set optimum write power with high precision. Trial writing is conducted by using write power Pw,m (where m is an integer) of a plurality of kinds, and a modulation M,m associated with each write power is calculated. Optimum asymptotic power Pasy-opt is calculated by performing predetermined computation by using reference asymptotic power Pasy-ref and reference write start power Pws-ref which are previously determined for each medium. An evaluated value S,m=M,m×(Pw,m?Pasy-opt) is calculated by using the optimum asymptotic power Pasy-opt. Write power Pw that makes the evaluated value S equal to zero when applying straight line approximation to a relation between the write power Pw,m and the evaluated value S,m is calculated as optimum write start power Pws-opt. And optimum write power Pw-opt is found by performing predetermined computation on the optimum write start power Pws-opt.

Abstract: An optical recording/reproducing apparatus includes an optical pickup unit configured to scan an optical disk with an optical signal to record and reproduce data. A power tuning unit is configured to scan a first track with the optical signal to record a first test data to the first track, while changing a power level of the optical signal within a predetermined range in sequence. A scanning time tuning unit is configured to scan a second track with an optical signal to record a second test data to the second track, while changing a scanning time within a predetermined range in sequence. A state detection unit is configured to detect a reproduction state of the first test data and second test data. A controller is configured to check the reproductions state of the first test data and second test data and determine an optimal power level and optimal scanning time. Accordingly, a write strategy is rapidly and optically tuned.

Abstract: A method and apparatus of controlling an optical disk apparatus determines a reference recording power at each of a plurality of recording speeds for an inserted optical disk, performs a power control procedure for a prescribed recording speed to determine a recording power at the prescribed recording speed in response to a recording request, and then computes a recording power at each of the recording speeds based on the reference recording power and the recording power determined at the prescribed recording speed. The power control procedure is performed only for an inner circumferential area of the disk, irrespective of whether a requested recording speed is less than or greater than the prescribed recording speed. As a result, the speed of the data recording operation may be substantially improved and/or other improvements may be realized.

Abstract: An input signal processing system is described. It comprises a first transconductance device having a first input, second input, and an output, wherein the first input is coupled to receive the input signal; a first resistor coupled to a first input of the first transconductance device, wherein the first resistor converts the input current signal to an input voltage signal; a first voltage-current converter coupled to the output, the second input, the resistor, and a low voltage supply, wherein the first voltage-current converter is operative for converting the input voltage signal to a input current signal; and a low pass filter having an input coupled to the voltage converter for filtering noise from the input current signal.

Abstract: A light irradiation power adjusting method includes a first recording step, a first reproducing step, a first measuring step, a bias power determining step and a recording power determining step. In the first recording step, an adjustment pattern is recorded to an optical information recording medium while fixing a recording power to a predetermined first power value and while changing a bias power among a plurality of second power values within a predetermined range. In the first reproducing step, the recorded adjustment pattern is reproduced so as to generate a reproduction signal. In the first measuring step, asymmetry values corresponding to the plurality of second power values are measured. In the bias power determining step, an optimum bias power value is determined based on the asymmetry values. In the recording power determining step, an optimum recording power value is determined based on the optimum bias power value.

Abstract: Recording information is disclosed in which an information recording medium is irradiated with a recording energy beam that is power-modulated into at least a record power level and a record-ready power level lower than the record power level. The information is recorded on the recording medium in the form of length and interval of a mark portion. When forming a mark portion of a predetermined length, the radiation energy of the energy beam is increased as compared with when forming a mark portion of a different length before or after the first pulse of an energy beam pulse train including at least a pulse for forming the mark portion.

Abstract: A method for setting recording power of recording light, capable of an appropriate setting for a multilayer optical recording medium. The recording power of the recording light for an information recording layer of the multilayer optical recording medium to be irradiated with, is set by: evaluating an information recording layer to be evaluated for recording power when all the information recording layer(s) lying closer to a light incident surface than the information recording layer to be evaluated does is/are in a low transmittance state; evaluating the information recording layer to be evaluated for recording power when all the information recording layer(s) lying closer to the light incident surface than the information recording layer to be evaluated does is/are in a high transmittance state; and determining ground information for setting recording power, based on these values of the recording power.

Abstract: In an information recording method and apparatus, when performing recording by using multiple pulses defined by erase powers Pe1 and Pe2 for forming a space part between mark parts, the set values of the erase powers Pe1 and Pe2 are updated at predetermined intervals in accordance with a recording linear velocity.

Abstract: A power determining method is disclosed for determining the light emitting power of a light source upon recording information on an optical disk having plural rewritable recording layers, the method involving obtaining an optimum erasing power with respect to an optimum recording power by recording test data on the optical disk.

Abstract: An information recording medium, comprising N number (N is an integer fulfilling N?3) of information layers on which information is recordable, and allowing information to be recorded on each of the information layers and allowing information recorded on each of the information layers to be reproduced by being irradiated with laser light. The N number of information layers include an N'th information layer, an (N?1)th information layer, an (N?2)th information layer, . . . a second information layer and a first information layer sequentially located from a laser light incidence side. A reflectance of the N'th information layer is RN, and a reflectance of an M'th information layer (M refers to every integer fulfilling N>M?1) is RM.

Abstract: An optical disc apparatus includes: an obtaining unit obtaining a sensitivity coefficient indicating a relation between a light power of a semiconductor laser and a monitor value; a first deriving unit deriving a first monitor value in setting the light power at a peak power; a second deriving unit deriving a second monitor value in setting the light power at an erase power; a converting unit converting the first and the second monitor values into first and second light power values based on the sensitivity coefficient; a first calculating unit calculating a ratio between the first and the second light power values; a second calculating unit calculating a correction coefficient based on a setting value of a ratio between the peak power and the erase power and a calculation value of the ratio between the first and the second light power values; and a correcting unit correcting the light power of the semiconductor laser based on the correction coefficient.

Abstract: In an optical recording medium having a plurality of recording layers on which information can be recorded by irradiating a laser beam from one side thereof, an optimum recording power to each of the recording layers can be determined. The optical recording medium has a plurality of recording layers on which information can be recorded by irradiating a laser beam from one side thereof, and each of the recording layers has a power calibration area (PCA) for optimizing the intensity of the laser beam.

Abstract: A last optimum parameter value control method is disclosed, with a laser parameter value being adjusted in a predetermined sequence at an ADIP/ATIP frame of an optical recording medium. Jitter is measured at each ADIP/ATIP frame in order to obtain an average jitter value for that particular frame, and hence parameter value.

Abstract: There is provided an optical information recording/reproducing apparatus capable of obtaining a high super-resolution effect using an optical information recording medium in which a super-resolution thin film is formed. An optical information recording medium 1 having a super-resolution layer is irradiated with a laser light in a light emission pattern such that a bias light emission portion that does not cause the super-resolution layer to be in the state of super-resolution and a pulse light emission portion that causes the super-resolution layer to be in the state of super-resolution alternatively appear, and reflected light is detected. A reproduction signal based on the pulse light emission portion and a reproduction signal based on the bias light emission portion are acquired.

Abstract: A recording apparatus (1) comprises a first calculating means (22) that calculates an optimum power to be used for recording a data pattern in a recording-scheduled area portion of a radially inner area (111); a first control means (22) that uses the optimum power to record a data pattern in an area portion radially outer than the recording-scheduled area portion; a second calculating means (22) that takes into account a difference between the recording sensitivity of the recording-scheduled area portion and the recording sensitivity of the area portion radially outer than the recording-scheduled area portion to calculate an adjustment power to be used for adjusting the recording condition in the area portion radially outer than the recording-scheduled area portion; a second control means (22) that records, in the area portion radially outer than the recording-scheduled area portion, a data pattern for adjusting the recording condition by use of the adjustment power; a reading means (12) that acquires a read

Abstract: By referring to a table of reproducing conditions and medium specific parameters, stored in an optical disc or optical disc apparatus and/or generated by the optical disc apparatus, the medium specific parameters to be used for performing reproducing power adjustment are changed in accordance with the reproducing condition to execute reproducing power adjustment.

Abstract: A laser power which is lower than an optimum reproduction laser power is set as an initial value. The reproduction laser power is increased from the initial value while trial reproduction is performed until a quality level of a reproduction signal is not lower than a reference level. At the time the quality level of the reproduction signal is not lower than the reference level, the reproduction laser power is set as the reproduction laser power with respect to an optical disk which is of a reproduction target.

Abstract: An apparatus for writing data to an optical storage media and a servo control unit and a laser diode driver unit thereof. The apparatus making a laser diode emit light includes a servo control unit and a laser diode driver unit. The servo control unit includes a control unit for controlling a burning procedure and a modulation unit for outputting an encoded signal. The laser diode driver unit receives the encoded signal and includes a PLL unit, a write strategy generation unit and a lock/unlock detection unit. The PLL unit outputs at least one of a second clock signal and a second data signal according to the encoded signal. The write strategy generation unit outputs a control signal to control the laser diode according to the second clock signal and the second data signal. The lock/unlock detection unit outputs a lock indicator or an unlock indicator to the control unit.

Abstract: In order to ensure a favorable recording characteristic for a write-once recording medium whose recording layer is made of an organic dye having an absorption spectrum at a wavelength ?=405 nm, this optical information recording apparatus includes a unit to set a write power to form recording marks, a space forming power to form spaces and a pulse width of a cooling pulse, and a unit to record information onto the recording medium according to the setting. The pulse width of the cooling pulse and a ratio of the space recording power to the write power are determined from a favorable region in a plane whose one coordinate axis represents the ratio and whose other coordinate axis represents the pulse width of the cooling pulse.

Abstract: An optical disk recording apparatus having (1) an optical pickup that emits laser light to illuminate a recording surface of an optical disk, receives reflected light resulting from the laser light reflected off the recording surface, and generates a light reception signal based on the thus received reflected light; (2) a laser power controller that sets a laser power setting and controls the power of the laser light emitted from the optical pickup based on the thus set laser power setting; and (3) a signal generator that, when a plurality of trial write areas provided on the recording surface of the optical disk are successively illuminated with the laser light in order to write trial write data, generates a timing notification signal that sets laser arrival timing when the laser light sequentially reaches trial write start positions of the plurality of trial write areas based on the light reception signal generated by the optical pickup.

Abstract: This invention allows super-resolution reproduction with which a better bER value is attainable, when information is recorded by a random pattern including a mark length not longer than a resolution limit, by use of a highly versatile signal decoding method. Information is recorded as marks and spaces coded by RLL(1,7) modulation, which each of the marks and spaces have one of a plurality of lengths, and 2 T marks and 2 T spaces of the marks and spaces being formed are shorter than 0.12 ?m. An information recording layer (20) includes a reproduction film (21) and a reflective film (22) which are provided in this order from a side from which reproducing light is incident, which reproduction film is made of (i) zinc oxide, (ii) strontium titanate, (iii) titanium oxide, (iv) cerium oxide, or (v) a material including at least one of the (i) through (iv), and which reflective film is made of tantalum or titanium.

Abstract: The method for estimating recording power Pow_tilting of a tilting part of a tilting disk is shown based on a power compensation formula: Pow_comp=A*(A*K). After a focus error (FE) signal of the tilting part of the tilting disk is manipulated as a focus servo output (FOO) signal, the parameter A is derived by low-pass filtering the FOO signal. Thereafter, another parameter K is then derived from a reference lookup table by using curve fitting approach based on parameter A such that the power compensation Pow_comp could be estimated by substituting parameters A and K into the above formula. A recording power Pow_tilting of the tilting part of the tilting disk could be estimated by adding a given recording power Piwrtpwr to the power compensation Pow_comp.

Abstract: In an optical information storage medium reproduction apparatus (10) for reproducing an optical information storage medium including a plurality of information recording layers each including a recording mark having a length shorter than an optical system resolution limit, reproduction laser power for reading an information recording layer closest to a reproduction-laser-incident surface of the optical information storage medium is set to be lower than reproduction laser power for reading an information recording layer farthest from the reproduction-laser-incident surface but not lower than minimum reproduction laser power that satisfies a reproduction signal characteristic that the optical information storage medium reproduction apparatus (10) requires.

Abstract: In an optical information storage medium reproduction apparatus (10) for reproducing an optical information storage medium including a plurality of information recording layers each including a recording mark having a length shorter than an optical system resolution limit, reproduction laser power for reading an information recording layer closest to a reproduction-laser-incident surface of the optical information storage medium is set to be lower than reproduction laser power for reading an information recording layer farthest from the reproduction-laser-incident surface but not lower than minimum reproduction laser power that satisfies a reproduction signal characteristic that the optical information storage medium reproduction apparatus (10) requires.

Abstract: In an optical information storage medium reproduction apparatus (10) for reproducing an optical information storage medium including a plurality of information recording layers each including a recording mark having a length shorter than an optical system resolution limit, reproduction laser power for reading an information recording layer closest to a reproduction-laser-incident surface of the optical information storage medium is set to be lower than reproduction laser power for reading an information recording layer farthest from the reproduction-laser-incident surface but not lower than minimum reproduction laser power that satisfies a reproduction signal characteristic that the optical information storage medium reproduction apparatus (10) requires.

Abstract: To record information as an array of optically changed portions arranged along a track in an optical storage medium, a pulsed laser beam is emitted toward the optical storage medium while causing at least one of the optical storage medium and the pulsed laser beam to be moved relative to each other. A plurality of pulses of the pulsed laser beam are emitted during a time span in which one segment of the track having a length corresponding to a length of one optically changed portion is scanned with the pulsed laser beam. An intensity of light with which a segment of the track is to be illuminated to form each individual optically changed portion is adjusted by causing a shutter to selectively reduce the number of pulses of the pulsed laser beam with which the segment of the track is to be illuminated.

Abstract: An optical disk apparatus for suppressing a DSV and performing R-OPC. An encoding/decoding circuit inserts a synchronization information item to a head of a synchronous frame once when data are recorded on an optical disk. First, the encoding/decoding circuit inserts synchronization information as a mark or a space on the basis of a DSV. When the polarity of the first synchronization information item is a mark, the polarity of a next synchronization information item is also set on the basis of the DSV. When the polarity of the first synchronization information is a space, the polarity of the next synchronization information is set to a mark. R-OPC is performed at a timing when the polarity of the synchronization information is a mark.

Abstract: In an optical information storage medium reproduction apparatus (10) for reproducing an optical information storage medium including a plurality of information recording layers each including a recording mark having a length shorter than an optical system resolution limit, reproduction laser power for reading an information recording layer closest to a reproduction-laser-incident surface of the optical information storage medium is set to be lower than reproduction laser power for reading an information recording layer farthest from the reproduction-laser-incident surface but not lower than minimum reproduction laser power that satisfies a reproduction signal characteristic that the optical information storage medium reproduction apparatus (10) requires.

Abstract: Ordinary optical disks need the resetting of recording conditions in the course of recording to cope with changes in ambient temperature, laser temperature, and medium's recording sensitivity. Optical disks for super-resolution reproduction which are intended to reproduce record marks smaller than the optical resolution, thereby increasing the recording density, need the resetting of recording conditions as well as the condition of super-resolution reproduction because the quality of reproduced signals depends largely on the power for super-resolution reproduction. The power for recording as well as the power for super-resolution reproduction is therefore changed in the course of test recording to detect the deviation from the optimum value of the recording condition to obtain the optimum recording power. In this case, it is also desirable to change the power for super-resolution reproduction in proportion to the power for recording.

Abstract: The invention is directed to provide an information recording apparatus having an adjusting process device which performs adjusting processes including an OPC process for optimizing a recording power for each of recording layers on a multilayer information recording medium, and an information recording device which performs an information recording process for each of the recording layers based on a result of the adjusting processes for each of the recording layers. The adjusting process device includes an initial adjusting process device which performs the adjusting processes at a start of information recording with the information recording device only for a start recording layer having the first recording start address, and an intermediate adjusting process device which performs the adjusting processes during information recording process with the information recording device for a recording layer other than the start recording layer.

Abstract: A method and apparatus for measuring the read stability of an optical disc are provided. Specifically, readout of the optical disc is repeated at each of at least two read laser beams powers being different from each other. A graph is drawn in which the inverses of the read powers are plotted on a horizontal axis and in which on a vertical axis is plotted the logarithm of a repeated readout number for each of the read powers. Here, the repeated readout number is the number of repetitions of the readout when a characteristic value for the number of repetitions of the readout varies and reaches a predetermined value. The read stability of the optical disc is evaluated by using the gradient of the graph.

Abstract: An information recording apparatus which irradiates a laser light onto a recording medium such as a DVD+R to record information records an adjustment RF signal in a PCA used for calibration of the laser light (OPC process). Thereby, on the recording medium having no recorded area of an RF signal in an entire circumference, such as the DVD+R, it becomes possible that the adjustment RF signal is recorded in the PCA to be read out and a mechanism adjustment and the like are executed. In addition, the information recording apparatus searches the inside of the PCA in order from the area having highly possibility that the adjustment RF signal is recorded. Thereby, the adjustment RF signal in the PCA can be rapidly detected.

Abstract: A reading devices suppresses deterioration of the recording marks caused by increasing the output laser power to compensate for a drop in the S/N ratio when reading at a high speed information recorded to a high density recording medium. To read information recorded to an optical data recording medium that is written and read using a laser beam output from a semiconductor laser, the reading method modulates a high frequency current on the drive current of the semiconductor laser to output the laser beam, and changes the light modulation rate according to the selected linear velocity used for reading. The light modulation rate is the ratio Pp/Pave between the peak power Pp and the average read power Pave of the light intensity of the high frequency modulated laser beam.

Abstract: A method of optimizing a writing condition of an optical recording medium, including writing test pattern data with the writing condition on the optical recording medium, comparing an error pattern binary signal detected by reproducing the written test pattern data with a correct pattern binary signal of the test pattern data, and determining an optimum writing condition of the optical recording medium based on a result of the comparison.

Abstract: A monitor optical device has a first region and a second region. The first region transmits part of light beam emitted from a light source to introduce the transmitted light beam to a monitor device. The second region reflects the remainder of the light beam to introduce the reflected light beam to an optical disk. The first region is formed at least within the second region.

Abstract: A super-resolution optical recording medium (10) of the present invention includes: a medium information region (1) on which medium identification information is recorded; a content region (3) on which content information is recorded; and a blank region (2) provided between the medium information region (1) and the content region (3) and in which at least two tracks are provided so as to connect a train of prepits in the medium information region (1) and a train of prepits in the content region (3). No information is recorded on the blank region (2). With this arrangement, the present invention provides a super-resolution optical recording medium in which a region on which medium identification information is recorded and a region on which content information is recorded are different in track pitch and in which a reproduction error hardly occurs when reproduction shifts from the region on which the medium identification information is recorded to the region on which the content information is recorded.

Abstract: A method and apparatus for controlling a light source for use with an optical disc having optimum power values for different stages in a writing signal for the optical disc, includes comparing current operational characteristics of the light source to previous operational characteristics, and, when the current operational characteristics differ from the previous operational characteristics and a stage in the writing signal has overlapping power, determining a compensation voltage based on the current operational characteristics and an optimum power value for that stage.

Abstract: An optical disc apparatus for recording or reproducing on or from an optical disc, comprising a laser light source for emitting a laser beam; a drive portion for driving the laser light source; a detection portion for detecting the emission power of the laser beam; and means for focusing the laser beam onto the optical disc, wherein information is reproduced by a reproducing power varied according to a recording power to obtain reproducing signals having necessary quality while suppressing deterioration of the recording quality due to the reproducing power.

Abstract: The present invention discloses read and write power control methods and system for an optical recording device that records information on an optical disk having read-only areas. The read and write power control methods respectively introduce the steps of determining a specific level of a former power control signal output based on a former power control, and then according to the specific level, setting a predetermined level of a power control signal to induce a present power control for rapidly outputting a proper power of the pick-up head. Accordingly, the level transition of the read/write power control signal can be shortened and even eliminated. An unstable read/write power output for the pick-up head can be avoided.

Abstract: The objects of the present invention are to facilitate the driving of the recording energy source, and to secure sufficient cooling time of the recording medium to promote the high-speed formation of high-precision marks and to provide high-speed and large-capacity information recording apparatuses at a low cost. To achieve the above objects, at the time of information recording, p is chosen as the integer constant for marks natural number k times long of the detection window width by referring to the mark length in the recording data sequence, the recording data sequence is discriminated according to the quotient obtained by and the remainder remaining after dividing k+p by two or more integer constants, and the energy generating means is driven according to different procedures based on the result of discrimination obtained thereby.

Abstract: An information recording medium, comprising N number (N is an integer fulfilling N?3) of information layers on which information is recordable, and allowing information to be recorded on each of the information layers and allowing information recorded on each of the information layers to be reproduced by being irradiated with laser light. The N number of information layers include an N?th information layer, an (N?1)th information layer, an (N?2)th information layer, . . . a second information layer and a first information layer sequentially located from a laser light incidence side. A reflectance of the N?th information layer is RN, and a reflectance of an M?th information layer (M refers to every integer fulfilling N>M?1) is RM.

Abstract: A power adjustment method in which a modulation index is calculated from reproduced signals of patterns recorded by irradiating light onto an optical information recording medium with a recording power varied and an optimum power of irradiation light is set up using the modulation index. The power adjustment method includes calculating an optimum value PcO of a predetermined correction term Pc using a relation of a value obtained by subtracting the predetermined correction term Pc from the recording power and the modulation index, finding a value Pth of the recording power at which the modulation index becomes substantially zero in the relation of the value obtained by subtracting the optimum value PcO from the recording power and the modulation index, and setting up a value obtained by multiplying the value of Pth by a predetermined constant as a recording power of each of the recording patterns.

Abstract: The reproduction durability of an optical recording medium is evaluated highly accurately in a short period of time by providing a method for evaluating the optical recording medium, the method including determining an operating laser power for heating a recording layer to a recording operating temperature; determining a temperature of the recording layer when a laser beam having a predetermined reproducing laser power is radiated during a data reproduction; determining a relationship between the reproducing laser power during the data reproduction and a reproduction durability times at the reproducing laser power; and determining a relationship between the temperature of the recording layer during the data reproduction and the reproduction durability times from the relationship between the reproducing laser power during the data reproduction and the reproduction durability times.

Abstract: A laser power control circuit includes a system control module for generating two write channel target values in a calibration mode, a driving module for driving a laser generator, and a detection module for detecting two laser power values of the laser generator. A write channel control module of the driving module generates two write channel signals according to the two write channel target values, respectively. The two laser power values respectively correspond to the two write channel signals. The system control module determines a first mapping relationship between a write channel target value and a laser power value according to the write channel target values and the laser power values. The system control module further determines a predetermined write channel target value corresponding to a predetermined laser power value according to the first mapping relationship in a run mode.

Abstract: A method for controlling read power and an open-loop read control device using the same. The open-loop read control device is used in an optical disk writer and includes a memory, a DAC and an amplifier. The optical disk writer includes a pickup head device having a laser diode. When writing is disabled, the read power of the optical disk writer for reading the disk corresponds to a specific voltage. The memory stores a relationship curve and outputs a corresponding reference value corresponding to the specific voltage. The DAC converts the corresponding reference value into an analog corresponding reference value. The amplifier receives the analog corresponding reference value and outputs a read power control voltage, which controls the laser diode to generate a substantially constant read power in the write process.

Abstract: An optical storage apparatus and a method for automatically adjusting a loop gain thereof are provided. The method includes the following steps. Firstly, a compact disk is written by an erase power. Next, a writing state of the erase power is detected to generate an error signal. Finally, a loop gain of a servo control loop is corrected according to the error signal. Therefore, the loop gain can be corrected by the present invention according to a reflectance of the compact disk.

Abstract: An optical storage apparatus and a method for eliminating a write power transient thereof are provided. The method includes following steps. First, a target voltage level of a write voltage when next time the optical storage apparatus writes data is obtained. Then, a command value is updated by using the target voltage level according to a relationship between the command value and the write voltage. Next, the write voltage of the optical storage apparatus is pre-charged to the target voltage level according to the updated command value. Thereby, the write power transient of the optical storage apparatus can be eliminated.

Abstract: A recording apparatus includes: an optical head section to irradiate a laser beam onto a recording medium and perform recording, reproduction, or erase of information; a laser drive section to drive the optical head section to output the laser beam; a modulation-degree measurement section to measure a modulation degree of a signal read out by the optical head section; and a control section to execute controlling the laser drive section and the optical head section to execute the recording and the erase on a test area of the recording medium while varying a laser power, calculating a power reference value based on an erase characteristic and a reproduced signal growth characteristic in accordance with the variation of the laser power, each of the characteristics being obtained by acquiring a modulation-degree measurement value of a reproduced signal, and setting a recording laser power by using the power reference value.

Abstract: Accurate calibration of recording power is performed without exceeding a rated output value of a laser diode even if recording speed is increased and high recording power is required. An information recording apparatus records information on an information recording medium such as a DVD-R/RW or a DVD+R/RW by applying a laser light onto the information recording medium. A pickup has a laser light source. A light receiving unit for detecting the amount of light by receiving the laser light emitted from the laser light source is provided, and the power of the laser light is controlled based on the power of the detected laser light. Before the actual information recording, a test emission is performed during calibration to determine an adequate recording power, and the emission duty of the laser light is controlled within the range not exceeding the rated output value of the laser light source.

Abstract: This document relates to a method and apparatus for controlling the current of a data line. The method may comprise determining a type of an optical disc inserted into the ODD, and differently controlling the current of the data line, coupled to a host, according to the determined type. If the optical disc is determined to be a disc of a video title, current to be applied to a level rising transition of the signal may be decreased, and if the optical disc is determined to be an audio disc or a data disc, the current of the data line may maintain a preset reference value. Accordingly, EMI occurring when a video title is played in the ODD can be minimized more efficiently.