An optical scanning apparatus includes first and second light sources, a rotatable polygonal mirror, a motor, first and second mirrors, first and second lenses, and a casing. Within a mounting range, a top wall of an accommodating portion is provided with at least one projection projecting toward an opening of the accommodating portion. The projection extends from a first side wall to a second side wall of the accommodating portion. The top wall includes a recess formed opposite from the projection, and is free from a portion projecting toward the opening over a range from the first side wall to the second side wall, other than the projection in the mounting range. A free end portion of the projection is in a position remoter from the opening than a reflecting surface of the rotatable polygonal mirror is with respect to a rotational axis direction of the motor.

A pixel clock generating device includes a high-frequency clock generator, a comparer, a pixel clock generator, and a value switcher. The high-frequency clock generator is configured to generate a high-frequency clock. The comparer is configured to measure a time interval between a leading-end synchronizing signal and a trailing-end synchronizing signal in a main scanning and calculate an error between the time interval and a target value. The pixel clock generator is configured to generate a pixel clock based on the high-frequency clock and a pixel clock frequency and correct the pixel clock based on the error. The value switcher, including a plurality of groups of values with which the pixel clock is generated, is configured to switch between the plurality of groups of values according to a switching signal after the trailing-end synchronizing signal is inputted, the comparer calculates the error, and the pixel clock generator corrects the pixel clock.

An image forming apparatus member includes a surface layer containing a Si-atom containing polymer as a major component. The dispersive component of the surface free energy of the surface layer is 25 mN/m or less, the dipole component of the surface free energy of the surface layer is 5 mN/m or less, and the hydrogen bonding component of the surface free energy of the surface layer is 5 mN/m or less.

An image forming apparatus includes a controller substrate, a first mounting portion for a first hard disk drive, a second mounting portion for a second hard disk drive, a first connector electrically connecting the controller substrate and the first hard disk drive, a second connector electrically connecting the controller substrate and the second hard disk drive. The second connector is shifted toward a side downstream of the first connector in a hard disk drive inserting direction so as to be prevented from overlapping with the first connector as seen in a vertical direction. In the second mounting portion, a through hole extending in the vertical direction is formed at a position where the through hole overlaps with the first connector as seen in the vertical direction.

An image forming apparatus includes a controller substrate, a first mounting portion for a first hard disk drive, a second mounting portion for a second hard disk drive, a first connector electrically connecting the controller substrate and the first hard disk drive, a second connector electrically connecting the controller substrate and the second hard disk drive. The second connector is shifted toward a side downstream of the first connector in a hard disk drive inserting direction so as to be prevented from overlapping with the first connector as seen in a vertical direction. In the second mounting portion, a through hole extending in the vertical direction is formed at a position where the through hole overlaps with the first connector as seen in the vertical direction.

In accordance with an embodiment, an image forming apparatus comprises a main scanning counter, a controller, and an interval determination section. The main scanning counter counts a first count value indicating the number of times a synchronization signal for synchronization between the apparatuses is input to itself, and registers the first count value to an initial value if a main scanning reference signal indicating a progress state of exposure in a main scanning direction is input to itself. The controller generates PreHSYNC generated at the same interval as the main scanning reference signal. The interval determination section determines that an abnormality occurs in the main scanning reference signal if the first count value satisfies a predetermined condition at a timing at which the PreHSYNC is input to itself.

An image forming apparatus includes a controller substrate, a first mounting portion for a first hard disk drive, a second mounting portion for a second hard disk drive, a first connector electrically connecting the controller substrate and the first hard disk drive, a second connector electrically connecting the controller substrate and the second hard disk drive. The second connector is shifted toward a side downstream of the first connector in a hard disk drive inserting direction so as to be prevented from overlapping with the first connector as seen in a vertical direction. In the second mounting portion, a through hole extending in the vertical direction is formed at a position where the through hole overlaps with the first connector as seen in the vertical direction.

An image forming apparatus includes a controller substrate, a first mounting portion for a first hard disk drive, a second mounting portion for a second hard disk drive, a first connector electrically connecting the controller substrate and the first hard disk drive, a second connector electrically connecting the controller substrate and the second hard disk drive. The second connector is shifted toward a side downstream of the first connector in a hard disk drive inserting direction so as to be prevented from overlapping with the first connector as seen in a vertical direction. In the second mounting portion, a through hole extending in the vertical direction is formed at a position where the through hole overlaps with the first connector as seen in the vertical direction.

A sheet discharging device includes a stacking portion configured to stack a sheet; a discharging portion configured to feed the sheet so as to be discharged to the stacking portion, wherein the discharging portion includes a first roller configured to feed the sheet and a second roller provided so as to be contactable to a sheet surface opposite from another sheet surface to which the first roller is contactable to; and an electrically discharging member configured to electrically discharge the sheet in contact with the sheet fed by the discharging portion. As viewed in a widthwise direction perpendicular to a discharging direction of the sheet, the electrically discharging member is provided so as to extend through between rotational axes of the first and second rollers in the discharging direction of the sheet.

An image heating apparatus includes an endless belt for heating a toner image on a sheet, a first detector for detecting a temperature of one longitudinal end portion of the endless belt, a second detector for detecting a temperature of the other longitudinal end portion of the endless belt, and a controller for controlling whether notification of generation of an error is provided on the basis of a change amount per unit time of a difference between the temperature detected by the first detector and the temperature detected by the second detector.