Abstract: A magnetic permeability detector includes an LC oscillator circuit including a coil and a capacitor; and a resistor connected in series with the coil.

Abstract: A magnetic permeability detector includes an LC oscillator circuit including a coil and a capacitor; and a resistor connected in series with the coil.

Abstract: A development device includes a developer bearer to carry by rotation developer to a development range facing a latent image bearer, and a planar metal developer regulator to adjust an amount of developer carried by the developer bearer to the development range. The developer bearer includes a developer carrying range having surface unevenness, and the developer regulator includes a fixed end portion held by a regulator holder and a free end portion to contact a surface of the developer bearer.

Abstract: A sheet size detector to detect a sheet size of a recording medium includes a movable member to move in a sheet size detection direction to a position corresponding to the sheet size, a magnetic flux detector including a coil disposed on a board face parallel to the sheet size detection direction to generate a magnetic flux in a direction perpendicular to the board face, and a target to oppose the board face and including a material to affect the magnetic flux. The target is different in configuration in the sheet size detection direction to change the magnetic flux in the direction perpendicular to the board face as the movable member moves. The magnetic flux detector outputs a signal corresponding to changes in magnetic flux in the direction perpendicular to the board face, and the signal corresponds to the position of the movable member.

Abstract: An image forming apparatus includes a latent image carrier; a latent image writer to write a latent image on the latent image carrier; a developing unit including a toner carrier having first and second electrodes insulated via an insulator member and a voltage applying unit to apply voltages to the first and second electrodes having a potential difference to generate first electric fields to cause the toner to hop from the toner carrier to the latent image carrier to develop a toner image; and a transfer unit to transfer the developed toner image to a transferring member. When alternating voltages having a same phase and same amplitude are applied to the first and second electrodes to form second electric fields between the latent image carrier and the toner carrier, the toner is discharged from the toner carrier to the latent image carrier in a toner discharge mode.

Abstract: A development device includes a developer bearer to carry by rotation developer to a development range facing a latent image bearer, and a developer regulator to adjust an amount of developer transported to the development range by the developer bearer. Multiple projections are formed in a surface of the developer bearer, and, in a direction in which the developer bearer rotates, a downstream end of each of the multiple projections is higher than an upstream end of the projection.

Abstract: An image forming apparatus includes a latent image carrier to carry a latent image, a developing device having a toner carrier with first and second electrodes to develop the latent image by transferring the toner to a developing region between the toner carrier and the latent image carrier while causing the toner to hop between the first and second electrodes and attaching the hopping toner to the latent image, a pulsed power supply to output a first periodic pulse voltage having a mean potential the same as a normal toner charge and a second periodic pulse voltage, a smoothing circuit to make the first periodic pulse voltage smooth to generate a direct voltage, and a toner layer thickness regulator member to regulate, on receiving the direct voltage, a thickness of the toner layer in a region between a toner supply position at which toner is supplied and the developing region.

Abstract: A magnetic permeability detector includes an LC oscillator circuit including a coil and a capacitor; and a resistor connected in series with the coil.

Abstract: A development device includes a developer container; a rotary cylindrical developer carrier including an outer electrode including multiple electrode portions arranged in a circumferential direction of the developer carrier, an inner electrode provided on an inner circumferential side of the developer carrier from the outer electrode, an insulation layer disposed between the outer electrode and the inner electrode, and a surface layer; and a bias power source to apply a first bias voltage and a second bias voltage to the inner electrode and the outer electrode, respectively. The first bias power source causes an electrical potential difference that changes with time between the inner electrode and the outer electrode to cause the developer to hop on a circumferential surface of the developer carrier. At least one of the first bias voltage and the second bias voltage has a cyclic waveform in which pulse-on time is reduced.

Abstract: A development device includes a toner carrier including first and second groups of electrodes, a toner supplier, and an electrical field generator. The electrical field generator includes a positive-phase pulse voltage generation circuit, a negative-phase pulse voltage generation circuit, a first DC power source for supplying a bias for setting a peak value of pulse voltages, a second DC power source to output a variable voltage having a polarity identical to a polarity of toner charge, a first diode having an anode connected to a lower potential side of the first DC power source and a cathode connected to an output terminal of the positive-phase pulse voltage generation circuit, and a second diode having an anode connected to the lower potential side of the first DC power source and a cathode connected to an output terminal of the negative-phase pulse voltage generation circuit.

Abstract: A development device includes a developer bearer to carry by rotation developer to a development range facing a latent image bearer, and a developer regulator to adjust an amount of developer transported to the development range by the developer bearer. Multiple projections are formed in a surface of the developer bearer, and, in a direction in which the developer bearer rotates, a downstream end of each of the multiple projections is higher than an upstream end of the projection.

Abstract: A disclosed developing device includes a toner carrying member having electrodes, a toner supply unit supplying the toner to the toner carrying member, and a hopping electric field generator unit generating electric field to cause the toner hopping on the toner carrying member by applying a pulse voltage to the electrodes. The hopping electric field generator unit includes a pulse voltage generator circuit generating the pulse voltage, a first direct-current power source supplying bias to the pulse voltage generator circuit for regulating a peak value of the pulse voltage, and a second direct-current power source having a same polarity with a toner charging polarity, and outputting a variable voltage level. The hopping electric field generator unit controls the peak value of the pulse voltage by changing an output of the first power source and a mean thereof by changing an output of the second power source.

Abstract: A development device includes a developer bearer to carry by rotation developer to a development range facing a latent image bearer, and a planar metal developer regulator to adjust an amount of developer carried by the developer bearer to the development range. The developer bearer includes a developer carrying range having surface unevenness, and the developer regulator includes a fixed end portion held by a regulator holder and a free end portion to contact a surface of the developer bearer.

Abstract: An image forming device, including a toner bearer including plural linear electrodes located at a first regular pitch in a crosswise direction thereof, flying a toner on the surface thereof between the plural linear electrodes with a pulse voltage thereto to form a floating toner layer; and a substrate including plural hole-electrode combinations arranged in a longitudinal direction of the linear electrodes, each formed of a through-hole and a hole-adjacent electrode located close to the through-hole, wherein the floating toner layer is formed in an area facing the through-hole, and a toner passes through only the through-holes facing a desired image from the floating toner layer with a record on or off voltage, and the plural hole-electrode combinations are lined at a second regular pitch in a crosswise direction of the toner bearer, and the second regular pitch is an integral multiple of the first regular pitch.

Abstract: An image forming apparatus comprises a toner-bearing member that bears toner and makes the toner clouded thereon. A toner passage control device including plural widthwise lines of toner passage holes in a printing medium conveyance direction is provided. Each of the toner passage holes includes a control electrode that controls passage of the toner through each of the toner passage holes toward a printing medium. a control pulse proving device provides a control pulse to the control electrode to operate. The control pulse applied to the control electrode of the one of the plural lines is different from that applied to the control electrode of the other one of the plural lines.

Abstract: An image forming apparatus is provided with a carriage in which recording heads having nozzles for ejecting liquid droplets are mounted and is configured to form an image on a recording medium being transported. The image forming apparatus includes a pattern forming unit that forms an impact position displacement adjustment pattern formed of plural independent liquid droplets on a water repellent member; a reading unit that includes a light emitting unit for emitting light onto the adjustment pattern and a light receiving unit for receiving specular reflection light from the adjustment pattern; and an impact position correcting unit that corrects an impact position of a liquid droplet to be ejected from the recording head based on a read result by the reading unit. The reading unit is disposed on the carriage and is arranged close to the side of a guide member that guides movement of the carriage.

Abstract: A disclosed liquid-jet device includes a liquid-jet head configured to jet liquid droplets; a pattern formation control unit configured to control the liquid-jet head and thereby to form a test pattern composed of separate liquid droplets on a water-repellent part; a detecting unit including a light-emitting element configured to illuminate the test pattern on the water-repellent part and a light-receiving element configured to receive specularly reflected light from the illuminated test pattern and to output a detection signal proportional to the received specularly reflected light; and a landing position adjusting unit configured to adjust landing positions of the liquid droplets based on the detection signal from the light-receiving element.

Abstract: An image forming apparatus includes a latent image carrier to carry a latent image, a developing device having a toner carrier with first and second electrodes to develop the latent image by transferring the toner to a developing region between the toner carrier and the latent image carrier while causing the toner to hop between the first and second electrodes and attaching the hopping toner to the latent image, a pulsed power supply to output a first periodic pulse voltage having a mean potential the same as a normal toner charge and a second periodic pulse voltage, a smoothing circuit to make the first periodic pulse voltage smooth to generate a direct voltage, and a toner layer thickness regulator member to regulate, on receiving the direct voltage, a thickness of the toner layer in a region between a toner supply position at which toner is supplied and the developing region.

Abstract: A development device includes a developer container; a rotary cylindrical developer carrier including an outer electrode including multiple electrode portions arranged in a circumferential direction of the developer carrier, an inner electrode provided on an inner circumferential side of the developer carrier from the outer electrode, an insulation layer disposed between the outer electrode and the inner electrode, and a surface layer; and a bias power source to apply a first bias voltage and a second bias voltage to the inner electrode and the outer electrode, respectively. The first bias power source causes an electrical potential difference that changes with time between the inner electrode and the outer electrode to cause the developer to hop on a circumferential surface of the developer carrier. At least one of the first bias voltage and the second bias voltage has a cyclic waveform in which pulse-on time is reduced.

Abstract: An image forming apparatus includes a latent image carrier; a latent image writer to write a latent image on the latent image carrier; a developing unit including a toner carrier having first and second electrodes insulated via an insulator member and a voltage applying unit to apply voltages to the first and second electrodes having a potential difference to generate first electric fields to cause the toner to hop from the toner carrier to the latent image carrier to develop a toner image; and a transfer unit to transfer the developed toner image to a transferring member. When alternating voltages having a same phase and same amplitude are applied to the first and second electrodes to form second electric fields between the latent image carrier and the toner carrier, the toner is discharged from the toner carrier to the latent image carrier in a toner discharge mode.