A PWM signal generation unit generates a PWM signal based on a driving voltage so that a midpoint of the longer period out of an H level period and an L level period in each PWM period matches a midpoint of the PWM period. FETs of a full bridge circuit (a driving circuit) are driven according to a PWM signal, and a driving current that corresponds to an A-phase is supplied to a stepping motor. A current detector detects a driving current flowing through an A-phase winding of the motor based on a voltage that is generated across a shunt resistor, at a fixed time point that is in each PWM period and in the H level or L level period that is at the center of the PWM period.

An image reading apparatus includes a main body unit, a sheet conveyance unit configured to convey a sheet, a conveyance path, a first image reading portion provided on the main body unit, and configured to read an image on a first surface of the sheet at a first reading position, a second image reading portion provided on the sheet conveyance unit downstream of the first image reading portion in a sheet conveyance direction, and configured to read an image on a second surface opposite from the first surface of the sheet at a second reading position, and a conveyance path securing portion arranged between the first reading position and the second reading position in the sheet conveyance direction, and configured to secure the conveyance path between an upper surface of the main body unit and a lower surface of the sheet conveyance unit.

A power supply device includes a DC power supply circuit to output a DC voltage, an AC power supply circuit to generate an AC voltage, and a power supply control circuit to control the DC power supply circuit and the AC power supply circuit. The AC power supply circuit outputs a superimposed voltage in which the DC voltage is superimposed with the AC voltage. The power supply control circuit controls the DC power supply circuit to output the DC voltage according to a DC output value corresponding to the AC voltage.

An image forming apparatus including an image bearer, a transfer-bias power source, an environment sensor, and a controller. The controller controls the transfer-bias power source to change the DC component and the AC component, according to the at least one of temperature and humidity detected by the environment sensor and a duty of the transfer bias. The duty is A/(A+B)×100[%] where A denotes an area on a return-directional side to move toner from the recording sheet back to the image bearer, relative to a center value (Voff) of a maximum value and a minimum value of the transfer bias in one cycle of a waveform of the transfer bias, and B denotes an area on a transfer-directional side to move the toner from the image bearer to the recording sheet, relative to the center value (Voff) in the one cycle.

An image forming apparatus includes: an image forming unit configured to form an image on contiguous paper; a job selecting unit configured to select a plurality of jobs to be continuously executed, by user operation; an amount-of-blank setting unit configured to set an amount of blank to be inserted between the plurality of jobs selected by the job selecting unit, by user operation; and a control unit configured to cause the image forming unit to form the image such that a blank of the amount of blank set by the amount-of-blank setting unit is inserted between the plurality of jobs.

A paper conveying apparatus and an image forming apparatus are described which can appropriately convey a sheet when the sheet is restarted after forming a loop. The paper conveying apparatus includes a conveying roller pair in the upstream side of a loop roller pair, a stepping motor for rotationally driving the conveying roller pair, and a processor for controlling rotation of the stepping motor by controlling pulse signals and excitation current supplied to the stepping motor. This processor halts rotation of the conveying roller pair by stopping output of the pulse signals when loop formation of the sheet is completed, and switches the excitation current to a lower current value which is lower than a reference current value at which excitation is turned on.

An image forming apparatus includes an image bearer, an image forming device to form a toner image on the image bearer with toner, a power source to output a bias to transfer the toner image onto a recording medium, and control circuitry. The circuitry controls the power source to decrease a peak-to-peak voltage of the bias in response to increase in at least one of temperature and humidity, when a time-averaged voltage of the bias is on a transfer side of transferring the toner to the recording medium, from a median value of maximum and minimum voltages of the bias. The circuitry controls the power source to increase the peak-to-peak voltage of the bias in response to increase in at least one of temperature and humidity, when the time-averaged voltage of the bias is on a return side of returning the toner to the image bearer, from the median value.

An additive manufacturing method produces a 3D part utilizes electrophotography-based additive manufacturing and molding processes. A layered structure having a cavity is printed on a build platform using at least one electrophotographic (EP) engine to develop imaged layers of powder material, and a transfusion assembly to stack and fuse the imaged layers on the build platform. Molding material is deposited into the cavity as the layered structure is printed, using a deposition unit. The molding material solidifies to form at least a portion of the 3D part, which may also include portions formed from imaged powder material.

An additive manufacturing method produces a 3D part utilizes electrophotography-based additive manufacturing and molding processes. A layered structure having a cavity is printed on a build platform using at least one electrophotographic (EP) engine to develop imaged layers of powder material, and a transfusion assembly to stack and fuse the imaged layers on the build platform. Molding material is deposited into the cavity as the layered structure is printed, using a deposition unit. The molding material solidifies to form at least a portion of the 3D part, which may also include portions formed from imaged powder material.

A document sheet conveyance device includes an inner guide and an outer guide defining a curved sheet conveyance passage for allowing conveyance of a document sheet from a document sheet feeding section to a predetermined document reading position, and a movable guide projectable into the sheet conveyance passage. The outer guide includes an outer curved guide surface defining an outer surface of the sheet conveyance passage. The inner guide includes an inner curved guide surface defining an inner surface of the sheet conveyance passage, and a first flat part. The movable guide includes a projecting portion projectable into the sheet conveyance passage, and a second flat part provided in the projecting portion. The movable guide is attached to the outer guide in such a way as to allow the first and second flat parts to face each other with the projecting portion projecting in the sheet conveyance passage.