Abstract: In an image forming apparatus, if a controller detects an abnormality in an output voltage of the power source device, the controller notifies the abnormality of the power source device. If the controller detects no abnormality in the output voltage after image data is input and before a scanner motor is activated in response to the input of the image data, the controller activates the scanner motor. If a rotary polygon mirror does not reach a target speed within a predetermined time, the controller re-detects whether there is an abnormality in the output voltage. If the controller detects an abnormality in the output voltage, the controller notifies the abnormality of the power source device. If the controller detects no abnormality in the output, the controller notifies the abnormality of the optical scanning device.

Abstract: A configuration in which print heads disposed on an upper cover and a control substrate disposed on a housing are electrically connected via cables. The cables connect the print heads and the control substrate while passing through the back side of the rotating shaft in the housing so that a part of the cables contacts the rotating shaft or a grounded metallic receiving member disposed near the rotating shaft for supporting a part of the cables.

Abstract: A configuration in which print heads disposed on an upper cover and a control substrate disposed on a housing are electrically connected via cables. The cables connect the print heads and the control substrate while passing through the back side of the rotating shaft in the housing so that a part of the cables contacts the rotating shaft or a grounded metallic receiving member disposed near the rotating shaft for supporting a part of the cables.

Abstract: In an image forming apparatus, if a controller detects an abnormality in an output voltage of the power source device, the controller notifies the abnormality of the power source device. If the controller detects no abnormality in the output voltage after image data is input and before a scanner motor is activated in response to the input of the image data, the controller activates the scanner motor. If a rotary polygon mirror does not reach a target speed within a predetermined time, the controller re-detects whether there is an abnormality in the output voltage. If the controller detects an abnormality in the output voltage, the controller notifies the abnormality of the power source device. If the controller detects no abnormality in the output, the controller notifies the abnormality of the optical scanning device.

Abstract: An image forming apparatus includes switches configured to switch a state of an operation performed by an assist circuit for a current supplied to a light-emitting element, in such a manner that the assist circuit corrects a value of a current supplied from a constant current source to the light-emitting element when a switching current is supplied in at least a period during which laser light scans a photoconductive drum and the assist circuit does not correct a value of a current supplied from the constant current source to the light-emitting element to make laser light incident on a photodiode to control a value of a bias current.

Abstract: An image forming apparatus includes switches configured to switch a state of an operation performed by an assist circuit for a current supplied to a light-emitting element, in such a manner that the assist circuit corrects a value of a current supplied from a constant current source to the light-emitting element when a switching current is supplied in at least a period during which laser light scans a photoconductive drum and the assist circuit does not correct a value of a current supplied from the constant current source to the light-emitting element to make laser light incident on a photodiode to control a value of a bias current.

Abstract: A bias circuit sets a value of a bias current using a correction coefficient ?=0.5 for a predetermined time period from when a state in which a first capacitor and a second capacitor are not charged, then changes the correction coefficient to ?=0.9 which is larger than ?=0.5, and sets a value of the bias current obtained by using the correction coefficient ?=0.9. The constant current source supplies the light emitting element with the bias current obtained by using the correction coefficient ?=0.9 and supplies the bias current with a switching current, and thus an electrostatic latent image is formed.

Abstract: A bias circuit sets a value of a bias current using a correction coefficient ?=0.5 for a predetermined time period from when a state in which a first capacitor and a second capacitor are not charged, then changes the correction coefficient to ?=0.9 which is larger than ?=0.5, and sets a value of the bias current obtained by using the correction coefficient ?=0.9. The constant current source supplies the light emitting element with the bias current obtained by using the correction coefficient ?=0.9 and supplies the bias current with a switching current, and thus an electrostatic latent image is formed.

Abstract: A present invention is provided with a laser light source having a plurality of laser elements capable of scanning a plurality of lines in parallel in a sub-scanning direction at a second resolution, which is higher than a first resolution of an image to be formed in a main scanning direction, a multiplexer and a laser driver that set a scaling ratio of an image in the sub-scanning direction in response to the first and second resolutions and an image size for image forming, and perform control so as to select and drive any of the plurality of laser elements of the laser light source in response to the scaling ratio that has been set, and an image forming unit that forms on a print medium an image of lines scanned using laser elements driven by the laser driver.

Abstract: An image forming apparatus comprises a scaling correction circuit that corrects scaling in a sub-scanning direction of image data according to scaling data, a screen processing circuit that, of image data whose scaling in the sub-scanning direction has been corrected by the scaling correction circuit, performs screen processing on image data included in a screen area; and an image forming unit that forms an image based on the image data that has been processed by the screen processing circuit. The scaling correction circuit changes the scaling in the sub-scanning direction such that a pixel arrangement of the screen area after the scaling is changed becomes a pixel arrangement of image data before the scaling was changed.

Abstract: A scanning optical apparatus uses a light source pair that includes at least two light sources to scan a same scan line. The scanning optical apparatus includes: a first group of light sources which include a first light source of a light source pair and are lined up on a first line; and a second group of light sources which include a second light source of the light source pair and are lined up on a second line. The first line and the second line are inclined with respect to reference lines corresponding to scan lines so that the first light source and the second light source of the light source pair scan the same scan line. Moreover, a distance between the first light source and the second light source of the light source pair is at least twice a distance between two adjacent light sources in the first line.

Abstract: A circuit for driving a semiconductor laser including a semiconductor integrated circuit, which controls the drive of the semiconductor laser, and is connected to one end of the semiconductor laser. Moreover, the driving circuit incorporates a first power source +Vcc that supplies by way of the semiconductor integrated circuit a drive voltage to one end of the semiconductor laser and a second power source ?Vcc, which is connected to the other end of the semiconductor laser and supplies a drive voltage to the other end. Furthermore, the drive circuit incorporates a voltage clamp circuit, connected to a connection terminal connecting the semiconductor laser and the semiconductor integrated circuit, for adjusting the electric potential of the connection terminal.

Abstract: A scanning optical apparatus uses a light source pair that includes at least two light sources to scan a same scan line. The scanning optical apparatus includes: a first group of light sources which include a first light source of a light source pair and are lined up on a first line; and a second group of light sources which include a second light source of the light source pair and are lined up on a second line. The first line and the second line are inclined with respect to reference lines corresponding to scan lines so that the first light source and the second light source of the light source pair scan the same scan line. Moreover, a distance between the first light source and the second light source of the light source pair is at least twice a distance between two adjacent light sources in the first line.

Abstract: A present invention is provided with a laser light source having a plurality of laser elements capable of scanning a plurality of lines in parallel in a sub-scanning direction at a second resolution, which is higher than a first resolution of an image to be formed in a main scanning direction, a multiplexer and a laser driver that set a scaling ratio of an image in the sub-scanning direction in response to the first and second resolutions and an image size for image forming, and perform control so as to select and drive any of the plurality of laser elements of the laser light source in response to the scaling ratio that has been set, and an image forming unit that forms on a print medium an image of lines scanned using laser elements driven by the laser driver.

Abstract: a circuit for driving a semiconductor laser including a semiconductor integrated circuit, which controls the drive of the semiconductor laser, and is connected to one end of the semiconductor laser. Moreover, the driving circuit incorporates a first power source +Vcc that supplies by way of the semiconductor integrated circuit a drive voltage to one end of the semiconductor laser and a second power source ?Vcc, which is connected to the other end of the semiconductor laser and supplies a drive voltage to the other end. Furthermore, the drive circuit incorporates a voltage clamp circuit, connected to a connection terminal connecting the semiconductor laser and the semiconductor integrated circuit, for adjusting the electric potential of the connection terminal.

Abstract: An image forming apparatus comprises a scaling correction circuit that corrects scaling in a sub-scanning direction of image data according to scaling data, a screen processing circuit that, of image data whose scaling in the sub-scanning direction has been corrected by the scaling correction circuit, performs screen processing on image data included in a screen area; and an image forming unit that forms an image based on the image data that has been processed by the screen processing circuit. The scaling correction circuit changes the scaling in the sub-scanning direction such that a pixel arrangement of the screen area after the scaling is changed becomes a pixel arrangement of image data before the scaling was changed.

Abstract: A circuit for driving a semiconductor laser including a semiconductor integrated circuit, which controls the drive of the semiconductor laser, and is connected to one end of the semiconductor laser. Moreover, the driving circuit incorporates a first power source +Vcc that supplies by way of the semiconductor integrated circuit a drive voltage to one end of the semiconductor laser and a second power source ?Vcc, which is connected to the other end of the semiconductor laser and supplies a drive voltage to the other end. Furthermore, the drive circuit incorporates a voltage clamp circuit, connected to a connection terminal connecting the semiconductor laser and the semiconductor integrated circuit, for adjusting the electric potential of the connection terminal.

Abstract: An image forming apparatus generates a PWM signal corresponding to input image data and controls a timing of a light source to emit a light beam based on the PWM signal in order to perform tone reproduction. The image forming apparatus includes a data processing unit configured to generate the PWM signal for one pixel based on image data for continuous two pixels in the image data. The data processing unit selects an origin of pulse growth in generation of the PWM signal for one pixel in accordance with the image data for the two pixels to generate the PWM signal.

Abstract: An image formation device changes the rotational rate of a polygon motor, i.e. the main-scanning rate, and selects one of pulse width conversion tables when an image formation is performed multiple times on a single sheet of transfer paper. The changing of the main-scanning rate is for preventing inconsistent sizes between a first recorded image and a second recorded image caused by shrinkage of transfer paper. The pulse width conversion tables allow the pulse widths to be modulated.

Abstract: A laser exposing apparatus has a first laser source emitting a first laser beam, a second laser source emitting a second laser beam shorter in wavelength than the first laser beam, and an optical device for directing the first laser beam and the second laser beam to a photosensitive member. The second laser beam has a longer optical path length to the photosensitive member than the first laser beam.