Abstract: An image formation apparatus includes an image carrier, a first charging member which abuts on the image carrier and charges the image carrier, a second charging member which abuts on the image carrier and charges the image carrier, the second charging member having such resistance characteristics as being less in variation with environmental variation than the first charging member, a power supply apparatus which can apply a voltage to each of the first and second charging members, and a control device which sets a voltage to be applied to the first charging member by the power supply apparatus based on a first amount of current which flows from the power supply apparatus through the first charging member to the image carrier and a second amount of current which flows to the image carrier through the second charging member.

Abstract: An image formation apparatus includes an image carrier, a first charging member which abuts on the image carrier and charges the image carrier, a second charging member which abuts on the image carrier and charges the image carrier, the second charging member having such resistance characteristics as being less in variation with environmental variation than the first charging member, a power supply apparatus which can apply a voltage to each of the first and second charging members, and a control device which sets a voltage to be applied to the first charging member by the power supply apparatus based on a first amount of current which flows from the power supply apparatus through the first charging member to the image carrier and a second amount of current which flows to the image carrier through the second charging member.

Abstract: An image forming apparatus that includes a plurality of heaters and in which a combination of each of the heaters to be turned on can be changed includes a current detection unit including a through-type current transformer in which current supply lines are inserted into or wound around a through hole; a turn-on information acquisition unit that acquires information on a turn-on mode indicating the combination of each of the heaters to be turned on as turn-on information; a connection information acquisition unit that acquires connection information on additive polarity connection and subtractive polarity connection of the heaters, wherein the current supply lines include an additive polarity connection line, and a subtractive polarity connection line; and an energization information acquisition unit that acquires information on an energized state of the plurality of heaters as energization information, based on the turn-on information, the connection information, and a current value.

Abstract: An image forming apparatus that includes a plurality of heaters and in which a combination of each of the heaters to be turned on can be changed includes a current detection unit including a through-type current transformer in which current supply lines are inserted into or wound around a through hole; a turn-on information acquisition unit that acquires information on a turn-on mode indicating the combination of each of the heaters to be turned on as turn-on information; a connection information acquisition unit that acquires connection information on additive polarity connection and subtractive polarity connection of the heaters, wherein the current supply lines include an additive polarity connection line, and a subtractive polarity connection line; and an energization information acquisition unit that acquires information on an energized state of the plurality of heaters as energization information, based on the turn-on information, the connection information, and a current value.

Abstract: An image forming apparatus that operates according to given operational conditions, comprising: a target power consumption receiving unit configured to receive a target value for power consumption; an option receiving unit configured to receive options selected by a user from among a plurality of options defining the operational conditions; a basic data storage unit storing therein basic data for each of the options; a calculation unit configured to calculate the estimated power consumption from the basic data according to the options selected by the user; an excess informing unit configured to inform the user when the estimated power consumption is greater than the target value; and an alternative option informing unit configured to inform the user of an alternative option when the estimated power consumption is greater than the target value, the alternative option reducing the estimated power consumption to be equal to or less than the target value.

Abstract: An image forming apparatus that heat-fixes a toner image onto a recording sheet passing through a fixing nip formed by pressing a pressurizing member against a heating rotational body heated by a heater, comprising: a storage unit storing a basic power consumption level of the heater determined in advance in a situation where inflow of inrush current to the heater is not occurring; an estimation unit calculating an estimated power consumption level of the heater by estimating an increase in the power consumption level, with respect to the basic power consumption level, brought about by inflow of inrush current to the heater; and an output unit outputting the estimated power consumption level. The heater switches between a heating state of receiving power supply and a non-heating state of not receiving power supply. The increase is estimated according to a duration of a non-heating state immediately preceding the heating state.

Abstract: After a toner image is transferred from a photoreceptor to an intermediate transfer belt, a surface of the photoreceptor is destaticized by a static eraser including a plurality of light emitting elements arranged in an axial direction of the photoreceptor. A first density sensor and a second density sensor for detecting densities of toner applied to the intermediate transfer belt are provided at a position where a large quantity of light from the static eraser is applied to the photoreceptor surface and a position where a small quantity of light from the static eraser is applied to the photoreceptor surface. In a case where a density difference between the detected toner densities exceeds a predetermined threshold value, a destaticization controller carries out an additional destaticizing operation by the static eraser.

Abstract: An image forming apparatus calculates a positional deviation in the main and sub-scanning directions for each color by forming registration patterns in two arrays along a sub-scanning direction on an image carrier. Each registration pattern in one array is paired with an identical registration pattern in the other array. A first sensor has: a light-emitting element irradiating one registration pattern in a pair; a photodetector for regular reflection light; and a photodetector for diffuse reflection light. A second sensor has: a light-emitting element irradiating the other one in the pair; and a photodetector for regular reflection light. The relative positions of a pair of registration patters calculated using the respective sensors are corrected so as to reduce the positional deviation between the calculated positions by the amount of offset deviation estimated occur between positions detected by the respective sensors when the registration patterns are without positional deviation.

Abstract: An image forming apparatus includes a first power calculator for calculating a power consumption amount of a driving load unit and a post-processing device based on at least one of measured values of a voltage and a current, which are supplied to the driving load unit and the post-processing device; second and third power calculators for calculating power consumption amounts of a fixing heater driving unit and a controller based on an operating state and an operating time of the image forming apparatus; and a power summing-up unit for calculating a power consumption amount of the image forming apparatus by summing up the power consumption amount calculated by the first power calculator and the power consumption amount predicted by each of the second and third power calculators.

Abstract: After a toner image is transferred from a photoreceptor to an intermediate transfer belt, a surface of the photoreceptor is destaticized by a static eraser including a plurality of light emitting elements arranged in an axial direction of the photoreceptor. A first density sensor and a second density sensor for detecting densities of toner applied to the intermediate transfer belt are provided at a position where a large quantity of light from the static eraser is applied to the photoreceptor surface and a position where a small quantity of light from the static eraser is applied to the photoreceptor surface. In a case where a density difference between the detected toner densities exceeds a predetermined threshold value, a destaticization controller carries out an additional destaticizing operation by the static eraser.

Abstract: An image forming apparatus that heat-fixes a toner image onto a recording sheet passing through a fixing nip formed by pressing a pressurizing member against a heating rotational body heated by a heater, comprising: a storage unit storing a basic power consumption level of the heater determined in advance in a situation where inflow of inrush current to the heater is not occurring; an estimation unit calculating an estimated power consumption level of the heater by estimating an increase in the power consumption level, with respect to the basic power consumption level, brought about by inflow of inrush current to the heater; and an output unit outputting the estimated power consumption level. The heater switches between a heating state of receiving power supply and a non-heating state of not receiving power supply. The increase is estimated according to a duration of a non-heating state immediately preceding the heating state.

Abstract: An image formation apparatus is connectable to a post processing apparatus for performing a post process to a sheet. The image formation apparatus includes: a power source for outputting a voltage to a first load and a second load, the first load being provided in the image formation apparatus and being involved in image formation, the second load being provided in the post processing apparatus and being involved in the post process; a power source controller for increasing the output voltage of the power source during an operation of the second load; and a load controller for controlling an operation of the first load such that an output of the first load falls within a predetermined range during the operation of the second load.

Abstract: An image forming apparatus calculates a positional deviation in the main and sub-scanning directions for each color by forming registration patterns in two arrays along a sub-scanning direction on an image carrier. Each registration pattern in one array is paired with an identical registration pattern in the other array. A first sensor has: a light-emitting element irradiating one registration pattern in a pair; a photodetector for regular reflection light; and a photodetector for diffuse reflection light. A second sensor has: a light-emitting element irradiating the other one in the pair; and a photodetector for regular reflection light. The relative positions of a pair of registration patters calculated using the respective sensors are corrected so as to reduce the positional deviation between the calculated positions by the amount of offset deviation estimated occur between positions detected by the respective sensors when the registration patterns are without positional deviation.

Abstract: An image forming apparatus includes a toner carrier, a toner image forming unit, and a toner concentration sensor. The toner carrier includes a transparent film. The toner image forming unit forms a toner image onto the toner carrier. The toner concentration sensor senses the concentration of toner on the toner carrier. The toner concentration sensor includes first and second light emitting elements and a light receiving element. The light emitting elements each radiate light directly or indirectly to the toner carrier. The light receiving element receives reflecting light originating from the light emitting elements. The first light emitting element radiates light having a wavelength of a predetermined reflectance resulting from direct radiation to the toner carrier. The second light emitting element radiates light having a wavelength that causes a lower reflectance resulting from direct radiation to the toner carrier than a reflectance resulting from radiation to the toner.

Abstract: An image forming apparatus includes a first power calculator for calculating a power consumption amount of a driving load unit and a post-processing device based on at least one of measured values of a voltage and a current, which are supplied to the driving load unit and the post-processing device; second and third power calculators for calculating power consumption amounts of a fixing heater driving unit and a controller based on an operating state and an operating time of the image forming apparatus; and a power summing-up unit for calculating a power consumption amount of the image forming apparatus by summing up the power consumption amount calculated by the first power calculator and the power consumption amount predicted by each of the second and third power calculators.

Abstract: An image forming apparatus that operates according to given operational conditions, comprising: a target power consumption receiving unit configured to receive a target value for power consumption; an option receiving unit configured to receive options selected by a user from among a plurality of options defining the operational conditions; a basic data storage unit storing therein basic data for each of the options; a calculation unit configured to calculate the estimated power consumption from the basic data according to the options selected by the user; an excess informing unit configured to inform the user when the estimated power consumption is greater than the target value; and an alternative option informing unit configured to inform the user of an alternative option when the estimated power consumption is greater than the target value, the alternative option reducing the estimated power consumption to be equal to or less than the target value.

Abstract: In this toner concentration sensor, as the magnetic permeability of a two-component developer 3 containing toner and carrier in a two-component developing unit 1 has changed with changing TC ratio of the two-component developer, the oscillation frequency of a first oscillation circuit 20 having a detection coil 5 changes, on the other hand the oscillation frequency of a second oscillation circuit 30 having a reference coil 6 does not change. While, changes in temperature conditions cause the oscillation frequency of the second oscillation circuit to change in the same way as the oscillation frequency of the first oscillation circuit. Therefore, utilizing a difference between the oscillation frequencies of the first and second oscillation circuits makes it possible to cancel out changes in the temperature conditions so that a value corresponding to only the magnetic permeability of the two-component developer can be obtained.

Abstract: In an image formation state, to cool a recording sheet on a route from a fixer to a paper ejection roller, a blast fan assumes a first position restrained by a first fixture. Also, in another state, to cool a recording sheet on the catch tray, the blast fan assumes a second position restrained by a second fixture. To transition from the image formation state to another state, the blast fan sends a strong blast in a reverse direction from the normal blast direction. A bias is generated on the blast fan due to the resulting reactive force, the blast fan becomes free from the restraint of the first fixture, and shifts from the first position to the second position. Conversely, to transition from another state to the image formation state, a strong blast is sent in the same direction as the normal blast direction, and the blast fan shifts from the second position to the first position.

Abstract: An image forming apparatus has a moving part that operates for forming an image on recording paper. When an instruction to make a transition to a silent mode is input to an input unit, first control is executed so that operation noise of the moving part is reduced. When an instruction to cancel the silent mode is input to the input unit, second control is executed so that the operation noise of the moving part is increased stepwise to return to the state before the first control.

Abstract: An image forming apparatus includes a toner carrier, a toner image forming unit, and a toner concentration sensor. The toner carrier includes a transparent film. The toner image forming unit forms a toner image onto the toner carrier. The toner concentration sensor senses the concentration of toner on the toner carrier. The toner concentration sensor includes first and second light emitting elements and a light receiving element. The light emitting elements each radiate light directly or indirectly to the toner carrier. The light receiving element receives reflecting light originating from the light emitting elements. The first light emitting element radiates light having a wavelength of a predetermined reflectance resulting from direct radiation to the toner carrier. The second light emitting element radiates light having a wavelength that causes a lower reflectance resulting from direct radiation to the toner carrier than a reflectance resulting from radiation to the toner.