Abstract: A developing device includes a rotatable liquid developer carrying member, a developer container, an electrode opposed to the developer carrying member with a predetermined gap therebetween to form an electric field, and an urging roller provided downstream of the electrode and upstream of a developing position to urge the developer carrying member. An amount of toner on the developer carrying member per unit area in a region downstream of the urging roller and upstream of the developing position with respect to the rotational moving direction is not less than 50% of an amount of the toner on the developer carrying member per unit area in a region interposed between the electrode and the developer carrying member.

Abstract: An image forming apparatus includes a corona charger including a discharging wire and a grid electrode for charging a photosensitive drum at a charging position and an exposure device for exposing the drum charged by the charger at an exposure position which is at a downstream side of the charger (in a rotational direction of the drum) at the charging position. The grid electrode includes a first portion having openings and a second portion having only a non-opening portion in a charging region for charging the drum in a longitudinal direction of the charger, and the second portion includes a downstream side peripheral portion at a downstream end of the grid electrode with respect to the rotational direction. In a cross-section orthogonal to the longitudinal direction and including the charging region, the downstream side peripheral portion is intersected by a straight line passing through the exposure position and the wire.

Abstract: An image forming apparatus includes a corona charger including a discharging wire, a grid electrode, for charging a photosensitive drum at a charging position; and an exposure device for exposing the drum charged by the charger at an exposure position which is in a downstream side of the charger in a rotational direction of the drum at the charging position. The grid electrode includes a first portion having openings and a second portion having only a non-opening portion in a charging region for charging the drum in a longitudinal direction of the charger, and the second portion includes a downstream side peripheral portion at a downstream end of the grid electrode with respect to the rotational direction. In a cross-section orthogonal to the longitudinal direction and including the charging region, the downstream side peripheral portion is intersected by a straight line passing through the exposure position and the wire.

Abstract: A developing device includes a rotatable developer carrying member configured to carry liquid developer including toner and carrier liquid; a developer container; an electrode opposed to the developer carrying member with a predetermined gap therebetween to form an electric field; an urging roller provided downstream of the electrode and the upstream of the developing position to urge the developer carrying member; wherein an amount of the toner on the developer carrying member per unit area in a region downstream of the urging roller and upstream of and the developing position with respect to the rotational moving direction is not less than 50% of an amount of the toner and the developer carrying member per unit area in a region interposed between the electrode and the developer carrying member.

Abstract: An image forming apparatus according to an embodiment of the present invention performs, at a predetermined timing, first gradation correction including forming a patch image on an image carrier, and correcting gradation characteristics of a formed image using a correction amount corresponding to the result of measurement of the patch image. The image forming apparatus further performs, at a predetermined frequency, second gradation correction including correcting the light power of laser light output from an exposure apparatus based on the result of detection or estimation of the charge amount of toner used in image formation, and correcting gradation characteristics using a correction amount corresponding to the result of the detection or estimation of the toner charge amount.

Abstract: An image forming apparatus which forms an image on an image carrier along with rotation of a developing sleeve that carries a toner and carrier contained in a two-component developer, comprises: forming unit configured to form a density detection toner image on the image carrier using the toner; detection unit configured to detect a density of the density detection toner image formed; prediction unit configured to predict a toner charge amount in the two-component developer; correction unit configured to correct the toner charge amount in the two-component developer using a value obtained from a relationship between the toner charge amount predicted by the prediction unit and the density of the toner image that is detected by the detection unit; and control unit configured, when forming the density detection toner image by the forming unit, to control to increase a development efficiency, compared to image formation based on image data.

Abstract: An image forming apparatus according to an embodiment of the present invention performs, at a predetermined timing, first gradation correction including forming a patch image on an image carrier, and correcting gradation characteristics of a formed image using a correction amount corresponding to the result of measurement of the patch image. The image forming apparatus further performs, at a predetermined frequency, second gradation correction including correcting the light power of laser light output from an exposure apparatus based on the result of detection or estimation of the charge amount of toner used in image formation, and correcting gradation characteristics using a correction amount corresponding to the result of the detection or estimation of the toner charge amount.

Abstract: An image forming apparatus which forms an image on an image carrier along with rotation of a developing sleeve that carries a toner and carrier contained in a two-component developer, comprises: forming unit configured to form a density detection toner image on the image carrier using the toner; detection unit configured to detect a density of the density detection toner image formed; prediction unit configured to predict a toner charge amount in the two-component developer; correction unit configured to correct the toner charge amount in the two-component developer using a value obtained from a relationship between the toner charge amount predicted by the prediction unit and the density of the toner image that is detected by the detection unit; and control unit configured, when forming the density detection toner image by the forming unit, to control to increase a development efficiency, compared to image formation based on image data.

Abstract: An image forming apparatus corrects a development contrast for normal image formation so as to satisfy the following relationships: VcontG2=VcontG1×VcontP2/VcontP1×?, and 0.9???1.1, where VcontP1 is a development contrast for a patch image formation before a correction by a first correcting device; VcontP2 is a development contrast for the patch image formation after the correction by the first correcting device; VcontG1 is a development contrast for normal image formation before a correction by a second correcting device; and VcontG2 is a development contrast for normal image formation after the correction by the second correcting device.

Abstract: An image forming apparatus capable of observing toner amount limitation with reliability even when two types of developers which have the same have and have different densities is provided. After an inputted image signal is subjected to color conversion processing to make the toner amount limitation, at least one color signal of the converted color signals is converted into signals for a dark color toner and a light color toner by light and dark separation using a single light and dark separation look-up table. Thereafter, the toner amount is determined again for each pixel. In the case where the toner amount exceeds a predetermined value, the light and dark separation of at least one color is made until the toner amount is the predetermined value or less by using another light and dark separation look-up table.

Abstract: An image forming apparatus corrects a development contrast for normal image formation so as to satisfy the following relationships: VcontG2=VcontG1×VcontP2/VcontP1×?, and 0.9???1.1, where VcontP1 is a development contrast for a patch image formation before a correction by a first correcting device; VcontP2 is a development contrast for the patch image formation after the correction by the first correcting device; VcontG1 is a development contrast for normal image formation before a correction by a second correcting device; and VcontG2 is a development contrast for normal image formation after the correction by the second correcting device.

Abstract: An electrostatic latent image is formed by controlling the amount of light, the emission time, and the like, considering the spot diameters of a laser, without changing the charging bias, the developing bias, and the like so as to obtain a plurality of correlations between density patches and development contrasts faithfully representing the developing characteristics of an image forming apparatus in a short time.

Abstract: An image forming apparatus includes a plurality of vibration members configured to vibrate a regulating member that regulates a developer layer thickness on a developer bearing member, and a control unit that can execute a vibration mode which vibrates the plurality of vibration members during different periods so that the plurality of vibration members do not vibrate simultaneously when an image is not being formed.

Abstract: An image forming apparatus includes an image carrier; an exposure unit configured to form an electrostatic latent image on the image carrier; a developing unit including a toner containing unit configured to accommodate a predetermined amount of toner, a toner supply unit configured to supply replenishment toner into the toner containing unit, a stirring unit configured to stir the toner to impart electric charge to the toner, a toner carrying member configured to carry the toner charged by the stirring unit, and a bias applying unit configured to apply a developing bias to the toner carrying member to develop the electrostatic latent image formed on the image carrier with the toner carried by the toner carrying member; a density sensor configured to detect a density of a toner pattern developed by the developing unit; and a control unit configured to control an amount of the toner supplied to the toner containing unit.

Abstract: An image forming apparatus capable of observing toner amount limitation with reliability even when two types of developers which have the same have and have different densities is provided. After an inputted image signal is subjected to color conversion processing to make the toner amount limitation, at least one color signal of the converted color signals is converted into signals for a dark color toner and a light color toner by light and dark separation using a single light and dark separation look-up table. Thereafter, the toner amount is determined again for each pixel. In the case where the toner amount exceeds a predetermined value, the light and dark separation of at least one color is made until the toner amount is the predetermined value or less by using another light and dark separation look-up table.

Abstract: An image forming apparatus includes a plurality of vibration members configured to vibrate a regulating member that regulates a developer layer thickness on a developer bearing member, and a control unit that can execute a vibration mode which vibrates the plurality of vibration members during different periods so that the plurality of vibration members do not vibrate simultaneously when an image is not being formed.

Abstract: An electrostatic latent image is formed by controlling the amount of light, the emission time, and the like, considering the spot diameters of a laser, without changing the charging bias, the developing bias, and the like so as to obtain a plurality of correlations between density patches and development contrasts faithfully representing the developing characteristics of an image forming apparatus in a short time.

Abstract: An image forming apparatus provided with an image bearing member bearing a toner image, the loss tangent tan ?1 of the image bearing member being 0.05?tan ?1?0.

Abstract: An image forming apparatus includes a latent image forming portion for forming an electrostatic latent image corresponding to image information on an image bearing member, a developing portion, having a developer container for accommodating a developer containing a toner and a carrier, for developing the electrostatic latent image with the toner, and a toner density detecting portion for detecting a toner density in the developer container, a toner replenishment amount to the developer container being controlled in accordance with a result of detection by the toner density detecting portion, wherein a toner replenishment amount target value used for controlling the toner replenishment is controlled to fall within a restriction range, and the restriction range can be changed according to the image information.

Abstract: An image forming apparatus includes a latent image forming portion for forming an electrostatic latent image corresponding to image information on an image bearing member, a developing portion, having a developer container for accommodating a developer containing a toner and a carrier, for developing the electrostatic latent image with the toner, and a toner density detecting portion for detecting a toner density in the developer container, a toner replenishment amount to the developer container being controlled in accordance with a result of detection by the toner density detecting portion, wherein a toner replenishment amount target value used for controlling the toner replenishment is controlled to fall within a restriction range, and the restriction range can be changed according to the image information.