Abstract: [Problem] To provide a stiffness measuring device capable of highly accurately measuring the stiffness of a recording material such as a sheet, and an image forming system equipped with the stiffness measuring device. [Solution] A stiffness measuring device includes a holding portion that holds a recording material so that a recording surface of the recording material is substantially parallel to a vertical direction, a pressing portion, and a stiffness acquiring section. The pressing portion presses a measurement point located on a lower side in the vertical direction than the portion of the recording material held by the holding portion. The stiffness acquiring section measure a reaction force obtained when the measurement point is pressed by the pressing portion and acquires the measured reaction force as the stiffness of the recording material.

Abstract: An image forming device includes: a transfer unit transferring a toner image to a sheet; a resistance measurement member disposed on the upstream side in a sheet carriage direction of the transfer unit and for measuring resistance of the sheet; a charge elimination member disposed between the transfer unit and the resistance measurement member in the sheet carriage direction; a first voltage applying unit applying voltage for resistance measurement to the resistance measurement member; and a second voltage applying unit applying voltage of reverse bias of the voltage for resistance measurement to the charge elimination member. The width of a charge elimination region by the charge elimination member is wider than that of a charged region by the resistance measurement member in a direction perpendicular to the sheet carriage direction. The absolute value of the voltage for charge elimination is smaller than that of the voltage for resistance measurement.

Abstract: An image forming device includes: a transfer unit transferring a toner image to a sheet; a resistance measurement member disposed on the upstream side in a sheet carriage direction of the transfer unit and for measuring resistance of the sheet; a charge elimination member disposed between the transfer unit and the resistance measurement member in the sheet carriage direction; a first voltage applying unit applying voltage for resistance measurement to the resistance measurement member; and a second voltage applying unit applying voltage of reverse bias of the voltage for resistance measurement to the charge elimination member. The width of a charge elimination region by the charge elimination member is wider than that of a charged region by the resistance measurement member in a direction perpendicular to the sheet carriage direction. The absolute value of the voltage for charge elimination is smaller than that of the voltage for resistance measurement.

Abstract: A power supply apparatus includes a predetermined mode in which power consumption is suppressed and a normal mode in which the power consumption is not suppressed and which supplies power to an apparatus. the power supply apparatus includes the following, a cutting member which cuts off supply of the power to a fixing heater; a noise removing member which is positioned in a later stage of the cutting member and which removes noise in the power; and a controller which controls the cutting member. The controller controls the cutting member to cut off supply of the power to the noise removing member in the predetermined mode.

Abstract: An image forming apparatus includes a high-voltage power supply board utilized for electrophotographic image formation, wherein a converter that generates high voltage is arranged on the high-voltage power supply board, and a drive coil and a high-voltage generation coil in the converter are insulated from each other, a first hardware processor that generates a control signal to control the drive coil is provided, the first hardware processor generates the control signal suitably adjusted in accordance with each of various alternating waveforms, and high voltage having various alternating waveforms is output from one output terminal of the converter of the high-voltage power supply board.

Abstract: A control device that controls an image former, includes: a second power supply that performs power feeding to a detector during a power feeding suspension period during which power feeding from a first power supply to the image former and the detector is not performed, the detector detecting an environment variable around the image former, the environment variable affecting quality of an image formed by the image former; and a determiner that determines a control condition for the image former in accordance with a result of detection performed by the detector during the power feeding suspension period, when power feeding from the first power supply to the image former is started at an end of the power feeding suspension period and the image former enters an image formation ready state in which the image former can perform image formation.

Abstract: A fixing apparatus includes: a fixing member including a heater as a heat source; and a hardware processor that uses pulse width modulation (PWM) control to control power supplied to the heater; wherein the hardware processor changes a duty of the PWM control within a half cycle of an input current of the PWM control.

Abstract: An information processing apparatus includes a first device and a second device, the first device includes a first power receiving member, a first switcher, a first power supply circuit, a failure detector, a second switcher, and a first electrical load, and the second device includes a second power receiving member, a second power supply circuit, a distributor, a third switcher, a second electrical load, and a hardware processor.

Abstract: A control device that controls an image former, includes: a second power supply that performs power feeding to a detector during a power feeding suspension period during which power feeding from a first power supply to the image former and the detector is not performed, the detector detecting an environment variable around the image former, the environment variable affecting quality of an image formed by the image former; and a determiner that determines a control condition for the image former in accordance with a result of detection performed by the detector during the power feeding suspension period, when power feeding from the first power supply to the image former is started at an end of the power feeding suspension period and the image former enters an image formation ready state in which the image former can perform image formation.

Abstract: An excessive heating protection circuit to be connected to a first temperature sensor being configured to output less voltage with a rise in temperature and a second temperature sensor being configured to output more voltage with a rise in temperature. The excessive heating protection circuit includes: a multiplexer having a plurality of channels capable of receiving reference voltages predetermined for the first and second temperature sensors, the multiplexer being configured to output one of the reference voltages by selecting one of the channels with reference to input selection signals; a first comparator being configured to compare the output voltage of the first temperature sensor to the output reference voltage of the multiplexer and to output a comparison result; and a second comparator being configured to compare the output voltage of the second temperature sensor to the output reference voltage of the multiplexer and to output a comparison result.

Abstract: An excessive heating protection circuit to be connected to a first temperature sensor being configured to output less voltage with a rise in temperature and a second temperature sensor being configured to output more voltage with a rise in temperature. The excessive heating protection circuit includes: a multiplexer having a plurality of channels capable of receiving reference voltages predetermined for the first and second temperature sensors, the multiplexer being configured to output one of the reference voltages by selecting one of the channels with reference to input selection signals; a first comparator being configured to compare the output voltage of the first temperature sensor to the output reference voltage of the multiplexer and to output a comparison result; and a second comparator being configured to compare the output voltage of the second temperature sensor to the output reference voltage of the multiplexer and to output a comparison result.

Abstract: An image forming apparatus forms decision registration mark for deciding whether or not a color registration correction for correcting color shifts in the color image carries out on an intermediate transfer belt. The decision registration mark is formed by registering four color registration marks. Color registration sensors detect a detection width of the decision registration mark along a sub scanning direction. A control portion receives the detection width of the decision registration mark and decides whether or not the color registration correction carries out based on whether or not the detection width of the decision mark detected by the detection portion exceeds the period of reference time. When the detection width of the decision mark detected by the detection portion exceeds the period of reference time, the control portion carries out the color registration correction.

Abstract: An image forming apparatus includes a plurality of heaters 56 for heating the fixing roller 52, a plurality of temperature sensors 57 for detecting the temperatures of the areas to be heated by the plurality of heaters 56 respectively, and a control unit 11 for turning on and off the plurality of heaters 56 on the basis of the temperatures detected by the plurality of temperature sensors 57. If one of the heaters 56 is on when the area to be heated by the other heater cools down to the ON temperature, the control unit 11 turns on the other heater with the same timing as the one heater is turned off.

Abstract: An image forming apparatus which allows a user to freely select a desired image quality is provided. The control unit 60 sets a of registration set value A1 for determining a color registration error suppression level and a dropout set value A2 for determining a dropout occurrence suppression level. Also, the control unit 60 sets a differential circumferential speed which is the difference between the circumferential speed of photoreceptor drums 1Y to 1K and the circumferential speed of an intermediate transfer belt 6 on the basis of the color registration set value A1 and the dropout set value A2. Then, the control unit 60 controls the belt drive motor 61 and the drum drive motor 62 on the basis of the differential circumferential speed which is set.

Abstract: An image forming apparatus includes an adjustment unit that adjusts an image transfer position of the sheet of paper along a main scanning direction that is orthogonal to a transporting direction of the sheet of paper, a fixing unit that fixes on the sheet of paper an toner image using fixing rollers and performs a fluctuation of the fixing roller to the main scanning direction, a detection unit that detects whether or not the fixing rollers of the fixing unit nip the sheet of paper, and a controller. The controller controls the fixing unit to perform the fluctuation of the fixing rollers when determining that the fixing rollers of the fixing unit do not nip the sheet of paper based on a detection result of the detection unit.

Abstract: An image forming apparatus forms decision registration mark for deciding whether or not a color registration correction for correcting color shifts in the color image carries out on an intermediate transfer belt. The decision registration mark is formed by registering four color registration marks. Color registration sensors detect a detection width of the decision registration mark along a sub scanning direction. A control portion receives the detection width of the decision registration mark and decides whether or not the color registration correction carries out based on whether or not the detection width of the decision mark detected by the detection portion exceeds the period of reference time. When the detection width of the decision mark detected by the detection portion exceeds the period of reference time, the control portion carries out the color registration correction.

Abstract: A printing control apparatus connected via a network with one or more of image forming apparatuses includes: a power source detection section which detects an image forming apparatus turned on; and a setting section which sets a mode shift time for shifting from a normal power mode to a power saving power mode a power consumption of which is less than a power consumption of the normal power mode of each of the image forming apparatuses; and a notice section which notices the set mode shift time to the image forming apparatus corresponding to the mode shift time, wherein the setting section changes the mode shift time when a plurality of image forming apparatuses which has been turned on is connected with the network, by comparing with a case when the network is connected with only one image forming apparatus turned on.

Abstract: An image forming apparatus includes a plurality of heaters 56 for heating the fixing roller 52, a plurality of temperature sensors 57 for detecting the temperatures of the areas to be heated by the plurality of heaters 56 respectively, and a control unit 11 for turning on and off the plurality of heaters 56 on the basis of the temperatures detected by the plurality of temperature sensors 57. If one of the heaters 56 is on when the area to be heated by the other heater cools down to the ON temperature, the control unit 11 turns on the other heater with the same timing as the one heater is turned off.

Abstract: An image forming apparatus which allows a user to freely select a desired image quality is provided. The control unit 60 sets a of registration set value A1 for determining a color registration error suppression level and a dropout set value. A2 for determining a dropout occurrence suppression level. Also, the control unit 60 sets a differential circumferential speed which is the difference between the circumferential speed of photoreceptor drums 1Y to 1K and the circumferential speed of an intermediate transfer belt 6 on the basis of the color registration set value A1 and the dropout set value A1. Then, the control unit 60 controls the belt drive motor 1 and the drum drive motor 62 on the basis of the differential circumferential speed which is set.

Abstract: An image forming apparatus includes: an image forming section which transfers a toner image in accordance with image data onto a recording sheet; a first fixing device having a first fixing roller, which fixes the toner image onto the recording sheet with heat; a second fixing device having a second fixing roller, which further applies heat to the recording sheet that has been fixed by the first fixing device; a second fixing roller surface roughness prevention mechanism which prevents a roughness on a surface of the second fixing roller that has been generated due to side ends of the recording sheet being brought into contact with the surface of the second fixing roller; and a controller which controls the image forming section, the first and second fixing devices and the second fixing roller surface roughness prevention mechanism.