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 image forming apparatus capable of minimizing color mis-registration due to runout of gears is disclosed. The image forming apparatus includes a plurality of photosensitive bodies having transfer points to transfer images onto a transfer object, a driving source to drive at least two photosensitive bodies of the plurality of photosensitive bodies, and a driving gear train to transmit driving power from the driving source to the at least two photosensitive bodies. The driving gear train includes photosensitive body shaft gears respectively connected to the photosensitive bodies driven by the driving source, and connecting gears to transmit the driving power to the photosensitive body shaft gears.

Abstract: A tandem color image forming apparatus includes a plurality of photosensitive bodies driven by one driving source and having a shaft gear, and power transmission members engaged with the shaft gears of the plurality of the photosensitive bodies to transmit a driving force generated from the driving source to each of the plurality of the photosensitive bodies. At least one color registration compensation unit is disposed between the power transmission members. The color image forming apparatus employs the color registration compensation unit so that each photosensitive body can be synchronized and registration errors can be minimized.

Abstract: A developing unit and an image forming apparatus having the developing unit are disclosed. The developing unit includes a developing unit main body having a supporting groove that contacts and is supported by the supporting protrusion of a frame when the developing unit is mounted on the mounting frame. A photoconductor is rotatably disposed in the developing unit main body and has ends that form a supporting shaft and are supported by a supporting unit. A driven unit is disposed in the developing unit main body and geared with the driving unit when the developing unit main body is mounted on the mounting frame. One of side surfaces of the developing unit main body includes an interference unit that interferes with the mounting frame and push the developing unit main body into engagement with the driving gear when the developing main body is mounted on the mounting frame.

Abstract: An apparatus and method for controlling a recording signal are provided. The apparatus may include a light generator generating light used to write information to an optical disk, a light amount compensator setting a voltage level of the recording signal as a second level when the write operation is performed or stopped, and a light amount controller supplying energy to the light generator based on the second level of the recording signal until the voltage level of the recording signal reaches a first level when a rewrite operation is started and controlling the light generated by the light generator to be constant after the voltage level of the recording signal reaches the first level.

Abstract: A step motor control circuit that does not fix a reference voltage of a step motor control signal. The step motor control circuit may include a digital-to-analog (DAC) signal generator configured to generate first and second DAC signals in response to a step motor error signal, a gain adjust block configured to control gains of the first and second DAC signals in response to a control signal and output first and second step motor control signals, and a gain controller configured to output the control signal in response to a mode signal and a gain control signal, in which the first and second step motor control signals are pulse trains including a reference voltage, and the reference voltage may be a fixed voltage when the mode signal indicates a normal mode and the reference voltage may be a variable voltage when the mode signal indicates a power consumption reduction mode.

Abstract: An ADIP (address in pre-groove) signal detection circuit is capable of correctly and quickly detecting discontinuous points in a wobble signal, and has a simple configuration in a wobble detection system of an optical disc device such as a DVD+R/RW, and an ADIP signal detection method thereof. The ADIP signal detection circuit performing the ADIP signal detection method includes one or two window comparators, two edge detection circuits each consisting of an exclusive OR circuit and an AND circuit, and two discontinuous point determination circuits each consisting of a flip-flop and a counter. Therefore, the ADIP signal detection circuit has a simple configuration so that it can be easily implemented. Also, since the ADIP signal detection circuit has a fast operation speed, the ADIP signal detection circuit detects discontinuous points correctly and quickly.

Abstract: A servo control system and method is provided, comprising: a controller outputting a parameter control signal; a device having a parameter controlled based on the parameter control signal; a sensing circuit sensing the parameter of the device and generating a parameter error signal; a sinusoidal signal generator generating a sinusoidal signal; and a adder combining the parameter error signal and the sinusoidal signal, wherein the controller includes a servo equalizer that equalizes the added parameter error signal and the sinusoidal signal to output an equalized parameter control signal to adjust the parameter.

Abstract: A method of controlling recording of an optical disc device and an optical disc device using the method. The optical disc device performs recording of data on a labeled surface of the optical disc. The device includes a buffer memory, a record unit and a controller. The buffer memory stores data and the record unit records data on the labeled surface of the optical disc from the buffer memory. The controller controls the record unit such that when a recording error occurs, the recording is stopped and when the error is corrected, data is recorded from a stopped position.

Abstract: A method of controlling a servo in an optical disc device and a servo control device using the method, in which the servo control device controls a servo for printing on a label surface of an optical disc and includes an optical pickup unit, an error signal generation unit, and a control unit. The optical pickup unit outputs a plurality of signals corresponding to a position of an object lens in response to light reflected from the label surface. The error signal generation unit outputs an error signal by selecting or combining one or more of the plurality of signals. The control unit adjusts the position of the object lens in response to the error signal. Therefore, because the position of the object lens can be adjusted with an increased range, the spot size of a beam condensed by the object lens can be adjusted within an increased range, and a data recording time can be reduced. Moreover, data retention characteristics and recording quality can be improved.

Abstract: An image forming apparatus capable of minimizing color mis-registration due to runout of gears is disclosed. The image forming apparatus includes a plurality of photosensitive bodies having transfer points to transfer images onto a transfer object, a driving source to drive at least two photosensitive bodies of the plurality of photosensitive bodies, and a driving gear train to transmit driving power from the driving source to the at least two photosensitive bodies. The driving gear train includes photosensitive body shaft gears respectively connected to the photosensitive bodies driven by the driving source, and connecting gears to transmit the driving power to the photosensitive body shaft gears.

Abstract: A servo control apparatus in an optical disc device and a method of controlling a servo are provided. When an image is printed on a surface of an optical disc, an irregular reflective surface results.

Abstract: A power transmission device and an image forming apparatus having the same that is capable of reliably transmitting intermittent power to a driven component from a driving source. The power transmission device includes a shaft, a first intermittent gear to receive power from the driving source and to rotate on the shaft, a second intermittent gear arranged so as to move between a first position in which the second intermittent gear is connected to the first intermittent gear along an axial direction of the shaft and a second position in which the second intermittent gear is disconnected from the first intermittent gear, a sliding unit arranged so as to slide along the shaft and to move the second intermittent gear in the axial direction of the shaft, and a driving unit to drive the sliding unit.

Abstract: A method of determining a recording power for a recordable optical disk in an optical disk system is provided. The method is capable of minimizing the time taken to determine an optimum recording power for each recording speed and thus improve recording performance.

Abstract: An image forming apparatus includes a developing unit to form an image using a developing agent on one side of a printing medium transported along a simplex printing path, a fixing unit to fix the developing agent on the printing medium, a discharging roller to discharge the printing medium that passes the fixing unit, and a first driving source to drive the developing unit, the fixing unit and the discharging roller.

Abstract: An optical disc system and a method of managing shock while recording or playing data in the optical disc system are provided. The optical disc system includes an optical pick-up unit for applying a laser beam to a track of an optical disc and detecting reflected light, a servo unit for controlling tracking and focus of the optical pick-up unit and a monitoring unit for comparing a monitoring signal, which is output from the optical pick-up unit and the servo unit, with a reference signal and generating a blocking signal and a blocking release signal. Recording or playing of data on the optical disc is stopped in response to the blocking signal, and recording or playing of the data on the optical disc is resumed in response to the blocking release signal based on a state of the optical disc system when recording or playing was stopped.

Abstract: An ADIP (address in pre-groove) signal detection circuit is capable of correctly and quickly detecting discontinuous points in a wobble signal, and has a simple configuration in a wobble detection system of an optical disc device such as a DVD+R/RW, and an ADIP signal detection method thereof. The ADIP signal detection circuit performing the ADIP signal detection method includes one or two window comparators, two edge detection circuits each consisting of an exclusive OR circuit and an AND circuit, and two discontinuous point determination circuits each consisting of a flip-flop and a counter. Therefore, the ADIP signal detection circuit has a simple configuration so that it can be easily implemented. Also, since the ADIP signal detection circuit has a fast operation speed, the ADIP signal detection circuit detects discontinuous points correctly and quickly.

Abstract: An image forming apparatus includes plurality image carriers sequentially arranged, a conveying belt, which conveys a print medium onto which color-separated images formed on the plurality of image carriers are overlapped, and a plurality of image transfer rollers installed to respectively correspond to the plurality image carriers. The conveying belt is interposed between the image transfer rollers and the image carriers. At least one of the plurality image transfer rollers is arranged to be compressed with a pressure higher than those applied to the other image transfer rollers against the image carriers.

Abstract: An ADIP (address in pre-groove) signal detection circuit is capable of correctly and quickly detecting discontinuous points in a wobble signal, and has a simple configuration in a wobble detection system of an optical disc device such as a DVD+R/RW, and an ADIP signal detection method thereof. The ADIP signal detection circuit performing the ADIP signal detection method includes one or two window comparators, two edge detection circuits each consisting of an exclusive OR circuit and an AND circuit, and two discontinuous point determination circuits each consisting of a flip-flop and a counter. Therefore, the ADIP signal detection circuit has a simple configuration so that it can be easily implemented. Also, since the ADIP signal detection circuit has a fast operation speed, the ADIP signal detection circuit detects discontinuous points correctly and quickly.

Abstract: An optical disc system and a method of managing shock while recording or playing data in the optical disc system are provided. The optical disc system includes an optical pick-up unit for applying a laser beam to a track of an optical disc and detecting reflected light, a servo unit for controlling tracking and focus of the optical pick-up unit and a monitoring unit for comparing a monitoring signal, which is output from the optical pick-up unit and the servo unit, with a reference signal and generating a blocking signal and a blocking release signal. Recording or playing of data on the optical disc is stopped in response to the blocking signal, and recording or playing of the data on the optical disc is resumed in response to the blocking release signal based on a state of the optical disc system when recording or playing was stopped.