Abstract: A motor control apparatus includes: a unit configured to determine a counter-electromotive voltage in a winding of a motor; a unit configured to determine a rotational position of a rotor of the motor based on the counter-electromotive voltage; a unit configured to determine a first velocity of the rotor, based on change in the rotational position; a correction unit configured to obtain a second velocity by correcting the first velocity based on a harmonic component included in the first velocity; and a driving unit configured to drive the motor based on the second velocity and the rotational position. The correction unit includes a unit configured to obtain the second velocity by reducing error in the first velocity that occurs due to the harmonic component.

Abstract: A motor control apparatus includes: a unit configured to determine a counter-electromotive voltage in a winding of a motor; a unit configured to determine a rotational position of a rotor of the motor based on the counter-electromotive voltage; a unit configured to determine a first velocity of the rotor, based on change in the rotational position; a correction unit configured to obtain a second velocity by correcting the first velocity based on a harmonic component included in the first velocity; and a driving unit configured to drive the motor based on the second velocity and the rotational position. The correction unit includes a unit configured to obtain the second velocity by reducing error in the first velocity that occurs due to the harmonic component.

Abstract: In an image forming apparatus, in the case where a time necessary for a developer bearing member to rotate from a measurement position where an attracting unit attracts the toner on the developer bearing member to a developing position at which an electrostatic latent image on the photosensitive member is developed by a toner on the developer bearing member is represented by a time Tqcm, a time necessary for the photosensitive member to rotate from an exposure position at which an exposure unit exposes the photosensitive member to the developing position is represented by a time Tetd, and a time necessary for a control unit to control an exposing condition based on a charge amount measured by a measuring unit is represented by a time Tp, the attracting unit is disposed so that Tqcm?Tedt+Tp holds true.

Abstract: First position information formed on a conveyance body is read by an information detecting portion, and second position information formed on a second image carrier is read by the information detecting portion. Control is made such that a position of an image on the second image carrier matches with a position of an image on the conveyance body from information read by the information detecting portion in transferring the image from the second image carrier to the conveyance body. The information detecting portion is held by a hold member and is disposed at a transfer region.

Abstract: A detection device configured to detect a charge amount of toner on a developer carrier includes an assembly with a quartz oscillator and having a first surface and a second surface that are provided in the quartz oscillator. The first surface has a recess and a projection formed in a direction in which the quartz oscillator vibrates. In addition, a capacitor is connected to the assembly, a first measurement unit measures a potential difference between two ends of the capacitor, and a second measurement unit measures a frequency of the quartz oscillator. In a case where an alternating-current power is applied to the assembly, the direction in which the quartz oscillator vibrates is parallel to the first surface.

Abstract: A non-contact power supply unit including a secondary coil supplies an alternating voltage to multiple heat generation layers provided in a heat generation film. In one of the heat generation layers, a loop is provided as a variable impedance circuit in which the impedance changes according to the frequency. A capacitance element in which the impedance changes according to the frequency is provided in the loop. The heat generation amounts of the heat generation layers are switched by changing the frequency of the alternating voltage generated in the secondary coil according to the size of the recording material that is the heating target.

Abstract: In a detection device, in a case where toner on a developing material carrier is caused to adhere to an electrode, a controller connects an assembly havin a quartz oscillator to a first capacitor using a first switch and connects the assembly to a second capacitor using a second switch; and in a case where a detection unit detects the oscillation frequency of the quartz oscillator, the controller disconnects the assembly from the first capacitor using the first switch and disconnects the assembly from the second capacitor using the second switch.

Abstract: A detection device configured to detect a charge amount of toner on a developer carrier, comprises: an assembly including a quartz oscillator and having a first surface and a second surface that are provided in the quartz oscillator, the first surface having a recess and a projection formed in a direction in which the quartz oscillator vibrates; a capacitor connected to the assembly; a first measurement unit configured to measure a potential difference between two ends of the capacitor; and a second measurement unit configured to measure a frequency of the quartz oscillator, wherein in a case where an alternating-current power is applied to the assembly, the direction in which the quartz oscillator vibrates is parallel to the first surface.

Abstract: An image forming apparatus improved in the accuracy of detecting a time period over which a laser beam is scanned. A laser beam emitted from a laser light source is deflected by a polygon mirror such that the laser beam scans a photosensitive drum. The deflected laser beam is guided onto the photosensitive drum via an imaging lens. A mode hop detection unit detects a mode hop of the laser beam. An image pulse generation section detects a main scanning magnification of an electrostatic latent image formed on the photosensitive drum. When a mode hop is detected, the main scanning magnification in a next scanning cycle is corrected using a correction value stored in a storage unit and used most lately, whereas when no wavelength variation has not detected, the main scanning magnification in the next scanning cycle is corrected using the latest correction value.

Abstract: A non-contact power supply unit including a secondary coil supplies an alternating voltage to multiple heat generation layers provided in a heat generation film. In one of the heat generation layers, a loop is provided as a variable impedance circuit in which the impedance changes according to the frequency. A capacitance element in which the impedance changes according to the frequency is provided in the loop. The heat generation amounts of the heat generation layers are switched by changing the frequency of the alternating voltage generated in the secondary coil according to the size of the recording material that is the heating target.

Abstract: In an image forming apparatus, in the case where a time necessary for a developer bearing member to rotate from a measurement position where an attracting unit attracts the toner on the developer bearing member to a developing position at which an electrostatic latent image on the photosensitive member is developed by a toner on the developer bearing member is represented by a time Tqcm, a time necessary for the photosensitive member to rotate from an exposure position at which an exposure unit exposes the photosensitive member to the developing position is represented by a time Tetd, and a time necessary for a control unit to control an exposing condition based on a charge amount measured by a measuring unit is represented by a time Tp, the attracting unit is disposed so that Tqcm?Tedt+Tp holds true.

Abstract: At detection device, in the case where the toner on the developing material carrier is caused to adhere to the first electrode, the controller connects the assembly to the first capacitor using the first switch and connects the assembly to the second capacitor using the second switch; and in the case where the second detection unit detects the oscillation frequency of the quartz oscillator, the controller disconnects the assembly from the first capacitor using the first switch and disconnects the assembly from the second capacitor using the second switch.

Abstract: An image forming apparatus includes a first station including a first photosensitive drum, a second station including a second photosensitive drum, and an intermediate transfer member for receiving the first toner image from the first drum and the second toner image from the second drum sequentially. In addition, a first sensor detects a first index image on the intermediate transfer member, and a second sensor detects a second index image on the second drum. A controller controls a peripheral speed of the second drum, and an executing device executes a test mode using a first test inclined index image and a second test inclined index image. The controller controls image forming conditions for the first and second index images in accordance with outputs of the first and second sensors in the test mode.

Abstract: A first position information formed on an conveyance body is read by an information detecting portion, and a second position information formed on a second image carrier is read by the information detecting portion. A control is made such that a position of an image on the second image carrier matches with a position of an image on the conveyance body from information read by the information detecting portion in transferring the image from the second image carrier to the conveyance body. The information detecting portion is held by a hold member and are disposed at a transfer region.

Abstract: A recording apparatus includes a recording unit configured to record images on a recording medium of a roll-type, the recording unit including a plurality of line-type recording heads, a first conveyance roller, located at an upstream side of the plurality of line-type recording heads, a second conveyance roller, located at a downstream side of the plurality of line-type recording heads, a first signal generation unit, including a laser doppler speed meter for detecting a surface of the recording medium being conveyed, a second signal generation unit, including a rotary encoder, a correction unit configured to correct the first signal when a period value of the first signal is outside a predetermined range, an information generation unit, and a control unit configured to control recording on the recording medium based on the variation information and the second signal so as to suppress adverse effects caused by the first conveyance roller.

Abstract: A recording apparatus that performs recording by ejecting ink onto a recording medium from a plurality of recording heads include a conveying roller that conveys the recording medium that is continuously fed; the plurality of recording heads arranged in the conveying direction of the conveying roller; a skew sensor that detects the amount of displacement of the position of the recording medium skewed in the widthwise direction perpendicular to the conveying direction relative to the recording heads when the recording medium is skewed with respect to the conveying direction; and an angle adjusting mechanism that rotates the recording heads relative to the recording medium on the basis of the amount of displacement detected by the skew sensor.

Abstract: An image forming apparatus improved in the accuracy of detecting a time period over which a laser beam is scanned. A laser beam emitted from a laser light source is deflected by a polygon mirror such that the laser beam scans a photosensitive drum. The deflected laser beam is guided onto the photosensitive drum via an imaging lens. A mode hop detection unit detects a mode hop of the laser beam. An image pulse generation section detects a main scanning magnification of an electrostatic latent image formed on the photosensitive drum. When a mode hop is detected, the main scanning magnification in a next scanning cycle is corrected using a correction value stored in a storage unit and used most lately, whereas when no wavelength variation has not detected, the main scanning magnification in the next scanning cycle is corrected using the latest correction value.

Abstract: An image forming apparatus includes a first station including a first photosensitive drum; a second station including a second photosensitive drum; an intermediate transfer member for receiving the first toner image from the first drum and the second toner image from the second drum sequentially; a first sensor configured to detect a first index image, on the intermediate transfer member; a second sensor for detecting a second index image on the second drum; a controller for controlling a peripheral speed of the second drum; an executing device for executing a test mode in which a first inclined test index image, and a second test inclined index image, wherein the controller controls image forming conditions for the first and second index images in accordance with outputs of the first second sensors in the test mode.

Abstract: First and second selection signals for selecting one of print data and n pulse signals stored in a shift register are latched. The first or second selection signal is selected in accordance with an input selection information switching signal, and one of the n input pulse signals is selected based on the selected signal. A heat pulse selection circuit outputs the selected pulse signal as a heat pulse signal. The level of the selection information switching signal switches midway to switch the selected pulse signal. Parts of two pulse signals before and after switching are combined to generate a heat pulse signal.

Abstract: In an ink jet printing apparatus using a plurality of printing heads arranged in a convey direction of a printing medium, an inclination angle of the printing medium to a predetermined convey direction is detected to adjust, in accordance with the resultant inclination angle, timings at which ink is jetted from the plurality of printing heads. This allows, even when the printing medium being subjected to a printing operation has a slight meander shape, an image to be formed on a printing medium so that printing positions of the plurality of printing heads have no dislocation.