Abstract: An electronic device that checks a connected state of a signal line is provided. The electronic device includes a controller configured to transmit a check signal and at least one module configured to include a closed loop and receive the check signal. When the controller receives the check signal through the closed loop, the controller determines that the at least one module is connected to the controller.

Abstract: An electronic device that checks a connected state of a signal line is provided. The electronic device includes a controller configured to transmit a check signal and at least one module configured to include a closed loop and receive the check signal. When the controller receives the check signal through the closed loop, the controller determines that the at least one module is connected to the controller.

Abstract: An image forming apparatus and an auto color registration method of the same which prints a color image by single pass, the image forming apparatus including: a plurality of developing units which each develops a color image in a predetermined color; a transfer unit which transfers the color image developed by developing units to the print medium and include a transfer belt rotatably installed on a transfer path; a first detector provided in a predetermined location of the transfer belt to face the transfer belt and detects any defect from a surface of the transfer belt; a second detector provided in a predetermined location of the transfer belt to face the transfer belt and detects a test pattern of an auto color registration (ACR) error transferred to the transfer belt; and a controller which adjusts the ACR error based on data detected by the first detector and the second detector.

Abstract: An image forming apparatus and an auto color registration method thereof. The automatic color registration method of the image forming apparatus, the method includes transferring a plurality of first patterns synchronized with a phase of an image receptor, detecting the transferred first patterns, and performing an automatic color registration (ACR) by controlling a driving speed of the image receptor based on the detected first pattern. With this, the apparatus and method controls a driving speed of an image receptor by using a pattern synchronized with a phase of the image receptor and improves accuracy of the ACR.

Abstract: An image forming apparatus and an auto color registration method of the same which prints a color image by single pass, the image forming apparatus including: a plurality of developing units which each develops a color image in a predetermined color; a transfer unit which transfers the color image developed by developing units to the print medium and include a transfer belt rotatably installed on a transfer path; a first detector provided in a predetermined location of the transfer belt to face the transfer belt and detects any defect from a surface of the transfer belt; a second detector provided in a predetermined location of the transfer belt to face the transfer belt and detects a test pattern of an auto color registration (ACR) error transferred to the transfer belt; and a controller which adjusts the ACR error based on data detected by the first detector and the second detector.

Abstract: An image forming apparatus includes: a plurality of optical scanning parts that scan a photoconductor with light of plural colors to form an electrostatic latent image on the photoconductor based on print data; and a controller that, based on a first optical scanning part to which a horizontal synchronization signal is applied of the optical scanning parts, calculates an offset value for light-scan of a second optical scanning part of the optical scanning parts, and controls the optical scanning parts to scan the photoconductor with the light according to the calculated offset value.

Abstract: A medium feeding unit having an improved structure for sensing that the number of print media loaded onto a loading plate is equal to or exceeds a predetermined remaining number, and an image forming apparatus having the same. The medium feeding unit includes a sensor that outputs sensing signals having different voltages according to quantities of received light. The medium feeding unit also includes a plurality of actuators that sense the number of print media on a loading plate, differentially intercept the sensing area of the sensor thus changing the voltage level of the sensing signal, and therefore signal the medium feeding unit when the number of print media on the loading plate falls below the predetermined remaining number.

Abstract: An image forming apparatus and an auto color registration method thereof. The automatic color registration method of the image forming apparatus, the method includes transferring a plurality of first patterns synchronized with a phase of an image receptor, detecting the transferred first patterns, and performing an automatic color registration (ACR) by controlling a driving speed of the image receptor based on the detected first pattern. With this, the apparatus and method controls a driving speed of an image receptor by using a pattern synchronized with a phase of the image receptor and improves accuracy of the ACR.

Abstract: A medium feeding unit having an improved structure for sensing that the number of print media loaded onto a loading plate is equal to or exceeds a predetermined remaining number, and an image forming apparatus having the same. The medium feeding unit includes a sensor that outputs sensing signals having different voltages according to quantities of received light. The medium feeding unit also includes a plurality of actuators that sense the number of print media on a loading plate, differentially intercept the sensing area of the sensor thus changing the voltage level of the sensing signal, and therefore signal the medium feeding unit when the number of print media on the loading plate falls below the predetermined remaining number.

Abstract: A video clock generation apparatus and method are provided. The apparatus comprises a ring oscillator for generating an oscillation frequency; a loopspeed detection unit for detecting a loopspeed that represents the number of pulses generated at the oscillation frequency when the ring oscillator oscillates for a predetermined time; and a video clock generation unit for suppressing generation of front-end video clock signals for a predetermined initial time, and after a first predetermined time following initialization of the effective video clock signals, maintaining a clock state of back-end video clock signals for a second predetermined time, wherein the front-end video clock signals precede effective video clock signals for image formation and the back-end video clock signals follow the effective video clock signals, and wherein the maintained clock state is the clock state prior to the second predetermined time clock signals.

Abstract: An image forming apparatus includes: a plurality of optical scanning parts that scan a photoconductor with light of plural colors to form an electrostatic latent image on the photoconductor based on print data; and a controller that, based on a first optical scanning part to which a horizontal synchronization signal is applied of the optical scanning parts, calculates an offset value for light-scan of a second optical scanning part of the optical scanning parts, and controls the optical scanning parts to scan the photoconductor with the light according to the calculated offset value.

Abstract: A ring oscillator setting apparatus and method depending on an environmental change of an image formation apparatus is provided. The apparatus includes a plurality of ring oscillators for generating different oscillation frequencies. The apparatus further includes a loopspeed detection unit to detect a loopspeed representing the number of pulses generated at the oscillation frequency by one of the ring oscillators selected from the plurality of ring oscillators for a predetermined unit time. Moreover, a state sensing unit is provided to detect a state of system environment of the image formation apparatus. A setting control unit is also provided to select and set one of the ring oscillators selected corresponding to change of the loopspeed detected from the loopspeed detection unit among the plurality of ring oscillators in response to the detected state of the state sensing unit.

Abstract: A video clock generation apparatus and method are provided. The apparatus comprises a ring oscillator for generating an oscillation frequency; a loopspeed detection unit for detecting a loopspeed that represents the number of pulses generated at the oscillation frequency when the ring oscillator oscillates for a predetermined time; and a video clock generation unit for suppressing generation of front-end video clock signals for a predetermined initial time, and after a first predetermined time following initialization of the effective video clock signals, maintaining a clock state of back-end video clock signals for a second predetermined time, wherein the front-end video clock signals precede effective video clock signals for image formation and the back-end video clock signals follow the effective video clock signals, and wherein the maintained clock state is the clock state prior to the second predetermined time clock signals.

Abstract: A ring oscillator setting apparatus and method depending on an environmental change of an image formation apparatus is provided. The apparatus includes a plurality of ring oscillators for generating different oscillation frequencies. The apparatus further includes a loopspeed detection unit to detect a loopspeed representing the number of pulses generated at the oscillation frequency by one of the ring oscillators selected from the plurality of ring oscillators for a predetermined unit time. Moreover, a state sensing unit is provided to detect a state of system environment of the image formation apparatus. A setting control unit is also provided to select and set one of the ring oscillators selected corresponding to change of the loopspeed detected from the loopspeed detection unit among the plurality of ring oscillators in response to the detected state of the state sensing unit.