Abstract: An image forming apparatus includes: a job acquirer that acquires a print job; a photoconductor including a surface on which a toner image is to be formed; an electrifying member that electrifies the photoconductor; an exposure member that exposes the photoconductor; a developing member that supplies toner to the photoconductor; a cleaner that cleans the photoconductor; and a controller connected to the job acquirer to control the image forming apparatus, wherein the controller computes a first non-toner region that is provided on the surface of the photoconductor when the toner image is formed on the photoconductor, the first non-toner region not containing toner in a longitudinal direction of the surface of the photoconductor, and the controller causes the exposure member and the developing member to form the toner image on the photoconductor and to form a set of toner patches in the first non-toner region.

Abstract: An image forming apparatus includes: a job acquirer that acquires a print job; a photoconductor including a surface on which a toner image is to be formed; an electrifying member that electrifies the photoconductor; an exposure member that exposes the photoconductor; a developing member that supplies toner to the photoconductor; a cleaner that cleans the photoconductor; and a controller connected to the job acquirer to control the image forming apparatus, wherein the controller computes a first non-toner region that is provided on the surface of the photoconductor when the toner image is formed on the photoconductor, the first non-toner region not containing toner in a longitudinal direction of the surface of the photoconductor, and the controller causes the exposure member and the developing member to form the toner image on the photoconductor and to form a set of toner patches in the first non-toner region.

Abstract: An image forming apparatus includes: a photoreceptor that forms a toner image on a surface of the photoreceptor; a charger that charges the surface of the photoreceptor; an exposure device that exposes the surface of the photoreceptor; a developer that supplies toner to the surface of the photoreceptor; an intermediate transfer belt for transferring the toner image formed on the surface of the photoreceptor; a density sensor that detects a density of the toner image on the intermediate transfer belt; and a controller that controls the image forming apparatus.

Abstract: An image forming apparatus includes: photoconductors rotatable and having toner images to be formed on surfaces; a transfer belt on which the toner images formed on the photoconductors are sequentially transferred; and a hardware processor that estimates timing of arrival of end of life of one photoconductor of the photoconductors due to depletion of the surface of the one photoconductor, wherein the hardware processor calculates a depletion amount of the one photoconductor due to a toner, as a first depletion amount, based on a first parameter having a positive correlation with an amount of the toner used for the toner image formed on the surface of another photoconductor that transfers the toner image on the transfer belt before the one photoconductor, and compares the calculated first depletion amount with a predetermined life estimation threshold value to estimate the timing of arrival of end of life of the one photoconductor.

Abstract: An image forming apparatus includes: photoconductors rotatable and having toner images to be formed on surfaces; a transfer belt on which the toner images formed on the photoconductors are sequentially transferred; and a hardware processor that estimates timing of arrival of end of life of one photoconductor of the photoconductors due to depletion of the surface of the one photoconductor, wherein the hardware processor calculates a depletion amount of the one photoconductor due to a toner, as a first depletion amount, based on a first parameter having a positive correlation with an amount of the toner used for the toner image formed on the surface of another photoconductor that transfers the toner image on the transfer belt before the one photoconductor, and compares the calculated first depletion amount with a predetermined life estimation threshold value to estimate the timing of arrival of end of life of the one photoconductor.

Abstract: A developing device includes a developer carrying member and first and second conveyance members. The first conveyance member conveys a developer in a first direction through a first conveyance path to the developer carrying member. The second conveyance member conveys the developer in a second direction through a second conveyance path included in a circulation path along with the first conveyance path. The second conveyance member has a helical second screw around a second shaft. The second conveyance path includes a developer replenishing port and a developer discharge port. The second screw is approximately constant in diameter in a second section being a portion extending a predetermined distance from an end of the discharge port in the second direction when viewed in a top view. The second screw conveys the developer at a lower speed in the second section than on an upstream side with respect to the second section.

Abstract: An image forming device includes: a charging unit configured to apply charging bias voltage to a charging member and charge a surface of an image carrying body; an exposure unit configured to expose the surface of the image carrying body, and form an electrostatic latent image; a developing unit configured to apply developing bias voltage to a developer carrying body, and develop the electrostatic latent image; and a control unit configured to control timing to start applying the developing bias voltage relative to timing to start applying the charging bias voltage, wherein the control unit performs control such that the larger an absolute value of the charging bias voltage is, the shorter an interval from timing to start applying the charging bias voltage to timing to start applying the developing bias voltage becomes, and such that the smaller the absolute value is, the longer the interval becomes.

Abstract: There are provided a developing device including a developing roller to develop an image carrier by use of a two-component developer and a developing bias power source, and an image forming apparatus using the developing device. The developing device further includes a variable resistance unit provided on a bias apply path to apply a bias from the developing power source to the developing roller, and a resistance controller to control a resistance value of the variable resistance unit based on a charge amount signal indicating a toner's charge amount in a developer layer on the developing roller. The resistance controller provides a low mode to lower the resistance of the variable resistance unit and a high mode to enhance the resistance. The low mode is set if the toner charge amount is low, and the high mode is set if the toner charge amount is high.

Abstract: A damage amount determination device, which is used for an image forming device that forms an image on paper, includes an information acquisition unit that acquires information related to whiteness of the paper used for printing and a damage amount determination unit that determines an amount of damage, which is caused by the paper to a predetermined component of the image forming device when the paper passes through the predetermined component, based on the information related to the whiteness.

Abstract: A developing apparatus that develops an electrostatic latent image on an image supporting body using developer including toner and carrier includes a circulation path where the developer circulates, a discharge path connected to the circulation path through which some of the developer passes, and a first recycle path connected to the discharge path and allowing some of the developer flowing into the discharge path to return to the circulation path. The discharge path includes a discharge opening for discharging the developer flowing into the discharge path, and a first return opening for connecting to the first recycle path. The first return opening is located on an upper side in a vertical direction with respect to the discharge opening and located on an upstream side in a pass-through direction of the developer flowing into the discharge path.

Abstract: An image forming device includes: a charging unit configured to apply charging bias voltage to a charging member and charge a surface of an image carrying body; an exposure unit configured to expose the surface of the image carrying body, and form an electrostatic latent image; a developing unit configured to apply developing bias voltage to a developer carrying body, and develop the electrostatic latent image; and a control unit configured to control timing to start applying the developing bias voltage relative to timing to start applying the charging bias voltage, wherein the control unit performs control such that the larger an absolute value of the charging bias voltage is, the shorter an interval from timing to start applying the charging bias voltage to timing to start applying the developing bias voltage becomes, and such that the smaller the absolute value is, the longer the interval becomes.

Abstract: There are provided a developing device comprising a developing roller to develop an image carrier by use of a two-component developer and a developing bias power source, and an image forming apparatus using the developing device. The developing device further includes a variable resistance unit provided on a bias apply path to apply a bias from the developing power source to the developing roller, and a resistance controller to control a resistance value of the variable resistance unit based on a charge amount signal indicating a toner's charge amount in a developer layer on the developing roller. The resistance controller provides a low mode to lower the resistance of the variable resistance unit and a high mode to enhance the resistance. The low mode is set if the toner charge amount is low, and the high mode is set if the toner charge amount is high.

Abstract: A developing device includes a developer carrying member and first and second conveyance members. The first conveyance member conveys a developer in a first direction through a first conveyance path to the developer carrying member. The second conveyance member conveys the developer in a second direction through a second conveyance path included in a circulation path along with the first conveyance path. The second conveyance member has a helical second screw around a second shaft. The second conveyance path includes a developer replenishing port and a developer discharge port. The second screw is approximately constant in diameter in a second section being a portion extending a predetermined distance from an end of the discharge port in the second direction when viewed in a top view. The second screw conveys the developer at a lower speed in the second section than on an upstream side with respect to the second section.

Abstract: A developing apparatus that develops an electrostatic latent image on an image supporting body, using developer including toner and carrier, includes: a circulation path where the developer circulates; a discharge path which is connected to the circulation path and through which some of the developer passes; and a first recycle path connected to the discharge path and allowing some of the developer flowing into the discharge path to return to the circulation path, wherein the discharge path is provided with: a discharge opening for discharging the developer flowing into the discharge path; and a first return opening for connecting to the first recycle path, and the first return opening is located on an upper side in a vertical direction with respect to the discharge opening and located on an upstream side in a pass-through direction of the developer flowing into the discharge path.

Abstract: A damage amount determination device, which is used for an image forming device that forms an image on paper, includes an information acquisition unit that acquires information related to whiteness of the paper used for printing and a damage amount determination unit that determines an amount of damage, which is caused by the paper to a predetermined component of the image forming device when the paper passes through the predetermined component, based on the information related to the whiteness.