Abstract: When a photosensitive member and a developing portion are in a separation state and in a start-up period, a first light emission is performed in an image region and a non-image region. When light is detected at least twice during a period when the first light emission is being performed, a second light emission is performed in the non-image region. When a prescribed period of time has elapsed from the start of the second light emission, a third light emission is performed in the image region in a third light emission amount that is smaller than a second light emission amount during a period in which the photosensitive member makes at least one revolution. After the third light emission is performed, the photosensitive member and the developing portion are switched to a contact state.

Abstract: In a photosensitive member and a developing portion are in a separation state and in a start-up period, a first light emission is performed in an image region and a non-image region; when light is detected at least twice during a period when the first light emission is being performed, a second light emission is performed in the non-image region; when a prescribed period of time has elapsed from the start of the second light emission, a third light emission is performed in the image region in a third light emission amount that is smaller than a second light emission amount during a period in which the photosensitive member makes at least one revolution; and, after the third light emission is performed, the photosensitive member and the developing portion are switched to a contact state.

Abstract: In a case of changing a first light quantity to a second light quantity which is smaller than the first light quantity, a light quantity changing unit changes a light quantity to a third light quantity, which is smaller than the first light quantity and larger than the second light quantity, before changing the light quantity to the second light quantity, and a third light quantity is a light quantity with which the signal is able to be output in a state where a first threshold is set.

Abstract: An image forming apparatus includes a control unit configured to detect a misregistration amount and densities of the toner images by detecting first and second detection patterns. The first detection pattern includes black and color portions, and the control unit is further configured to set a light-emitting amount of a detection unit, a threshold, or a sensitivity of a detection unit so that a received light amount of diffuse reflection light from the black portion is less than the threshold and a received light amount of diffuse reflection light from the color portion exceeds the threshold, and to set the light-emitting amount or the sensitivity so that the received light amount of the diffuse reflection light from the color portion is less than an upper limit of the detection unit.

Abstract: In a case of changing a first light quantity to a second light quantity which is smaller than the first light quantity, a light quantity changing unit changes a light quantity to a third light quantity, which is smaller than the first light quantity and larger than the second light quantity, before changing the light quantity to the second light quantity, and a third light quantity is a light quantity with which the signal is able to be output in a state where a first threshold is set.

Abstract: An image forming apparatus includes: an image forming unit configured to form, on an image carrier, a first correction pattern including developer images of a plurality of colors, and a second correction pattern including developer images of the plurality of colors; a registration correction unit configured to perform registration correction control based on a detection result of the developer images of the first correction pattern; and a density correction unit configured to perform density correction control based on a detection result of the second correction pattern. The density correction unit is further configured to decide a detection result of the developer image of at least one color of the second correction pattern used for the density correction control based on a detection result of the developer image of the first correction pattern.

Abstract: An image forming apparatus includes a forming unit configured to continuously form, on an image carrier, first and second detection patterns for detecting relative registration amounts and a density of each of a plurality of colors; and a control unit configured to control registration and the density. The forming unit forms the detection patterns such that a leading edge developer color of a detection pattern formed on a front side among the two detection patterns, in a direction in which the detection patterns are moved by rotation of the image carrier, is the same as a trailing edge developer color of the detection pattern formed on the front side, or a leading or trailing edge developer color of a detection pattern formed on a rear side among the two detection patterns.

Abstract: An image forming apparatus includes a forming unit configured to continuously form, on an image carrier, first and second detection patterns for detecting relative registration amounts and a density of each of a plurality of colors; and a control unit configured to control registration and the density. The forming unit forms the detection patterns such that a leading edge developer color of a detection pattern formed on a front side among the two detection patterns, in a direction in which the detection patterns are moved by rotation of the image carrier, is the same as a trailing edge developer color of the detection pattern formed on the front side, or a leading or trailing edge developer color of a detection pattern formed on a rear side among the two detection patterns.

Abstract: An image forming apparatus includes an image forming unit configured to form a density detection pattern and a reference pattern on an image carrier by a developer; a light-receiving unit configured to receive reflection light of light emitted toward the image carrier, and output a signal corresponding to an amount of received light; a sampling unit configured to sample the signal output from the light-receiving unit, and store sampling values in the storage unit; a detection unit configured to detect the reference pattern; and a determination unit configured to determine a sampling value corresponding to reflection light from the density detection pattern of the color among the sampling values stored in the storage unit, based on a detection time of the reference pattern.

Abstract: An image forming apparatus includes a control unit configured to detect a misregistration amount and densities of the toner images by detecting first and second detection patterns. The first detection pattern includes black and color portions, and the control unit is further configured to set a light-emitting amount of a detection unit, a threshold, or a sensitivity of a detection unit so that a received light amount of diffuse reflection light from the black portion is less than the threshold and a received light amount of diffuse reflection light from the color portion exceeds the threshold, and to set the light-emitting amount or the sensitivity so that the received light amount of the diffuse reflection light from the color portion is less than an upper limit of the detection unit.

Abstract: An image forming apparatus includes: a forming unit configured to continuously form, on an image carrier, a first and second detection patterns for detecting relative registration amounts and a density of each of a plurality of colors; and a control unit configured to control registration and the density. The forming unit forms the detection patterns such that a leading edge developer color of a detection pattern formed on a front side among the two detection patterns, in a direction in which the detection patterns are moved by rotation of the image carrier, is the same as a trailing edge developer color of the detection pattern formed on the front side, or a leading or trailing edge developer color of a detection pattern formed on a rear side among the two detection patterns.

Abstract: An image forming apparatus includes: image forming unit configured to form a density detection pattern and a reference pattern on an image carrier by a developer; a light-receiving unit configured to receive reflection light of light emitted toward the image carrier, and output a signal corresponding to an amount of received light; a sampling unit configured to sample the signal output from the light-receiving unit, and store sampling values in the storage unit; a detection unit configured to detect the reference pattern; and a determination unit configured to determine a sampling value corresponding to reflection light from the density detection pattern of the color among the sampling values stored in the storage unit, based on a detection time of the reference pattern.

Abstract: An image forming apparatus includes: an image forming unit configured to form, on an image carrier, a first correction pattern including developer images of a plurality of colors, and a second correction pattern including developer images of the plurality of colors; a registration correction unit configured to perform registration correction control based on a detection result of the developer images of the first correction pattern; and a density correction unit configured to perform density correction control based on a detection result of the second correction pattern. The density correction unit is further configured to decide a detection result of the developer image of at least one color of the second correction pattern used for the density correction control based on a detection result of the developer image of the first correction pattern.

Abstract: An image forming apparatus that reduces a time period during which no image is formed due to a margin in leading end portion, by calculating the margin in leading end portion from position information of an image and moving forward output timing of a /TOP signal according to the margin in leading end portion.

Abstract: An image forming apparatus is configured to control the timing to switch a development unit by a development rotary after forming an image, based on the size of the image to be formed. Accordingly, if the switching of the development unit is completed within a time period corresponding to a trailing edge margin of an image area, a subsequent color image can be formed without idling an intermediate transfer member, so that the image forming apparatus can suppress or reduce degradation of the throughput.

Abstract: An image forming apparatus is configured to control the timing to switch a development unit by a development rotary after forming an image, based on the size of the image to be formed. Accordingly, if the switching of the development unit is completed within a time period corresponding to a trailing edge margin of an image area, a subsequent color image can be formed without idling an intermediate transfer member, so that the image forming apparatus can suppress or reduce degradation of the throughput.

Abstract: An image forming apparatus is configured to control the timing to switch a development unit by a development rotary after forming an image, based on the size of the image to be formed. Accordingly, if the switching of the development unit is completed within a time period corresponding to a trailing edge margin of an image area, a subsequent color image can be formed without idling an intermediate transfer member, so that the image forming apparatus can suppress or reduce degradation of the throughput.

Abstract: An image forming apparatus that reduces a time period during which no image is formed due to a margin in leading end portion, by calculating the margin in leading end portion from position information of an image and moving forward output timing of a /TOP signal according to the margin in leading end portion.

Abstract: An image forming apparatus is configured to control the timing to switch a development unit by a development rotary after forming an image, based on the size of the image to be formed. Accordingly, if the switching of the development unit is completed within a time period corresponding to a trailing edge margin of an image area, a subsequent color image can be formed without idling an intermediate transfer member, so that the image forming apparatus can suppress or reduce degradation of the throughput.