Abstract: In a reserved seat monitoring system, a control unit acquires image information of an angle of view including a seat of interest that is reserved and surrounding seats within a predetermined region based on the seat of interest, determines whether an object overlapping the seat of interest is present by using a result of analysis of the image information, and in a case where the object is determined to be present, calculates a probability that occupation of the object is resolved during a reservation changeable period for the seat of interest and when the calculated probability is lower than a predetermined value, notifies a change in reservation to a person reserving the seat of interest.

Abstract: An image forming apparatus includes a latent image bearer, an electrostatic latent image forming device, a potential sensor, a toner image forming device, a toner adhesion amount detector, and circuitry. The circuitry controls the electrostatic latent image forming device to create an adjustment pattern on the latent image bearer when the image forming apparatus is not printing, controls the potential sensor to detect an electric potential of the adjustment pattern, controls the electrostatic latent image forming device and the toner image forming device to create a test toner image during a printing period, controls the toner adhesion amount detector to detect a toner adhesion amount of the test toner image, and adjusts at least one image forming condition of the electrostatic latent image forming device and the toner image forming device based on the electric potential of the adjustment pattern and the toner adhesion amount of the test toner image.

Abstract: An image forming apparatus includes a latent image bearer, an electrostatic latent image forming device, a potential sensor, a toner image forming device, a toner adhesion amount detector, and circuitry. The circuitry controls the electrostatic latent image forming device to create an adjustment pattern on the latent image bearer when the image forming apparatus is not printing, controls the potential sensor to detect an electric potential of the adjustment pattern, controls the electrostatic latent image forming device and the toner image forming device to create a test toner image during a printing period, controls the toner adhesion amount detector to detect a toner adhesion amount of the test toner image, and adjusts at least one image forming condition of the electrostatic latent image forming device and the toner image forming device based on the electric potential of the adjustment pattern and the toner adhesion amount of the test toner image.

Abstract: An image forming apparatus includes a latent image bearer, a toner image forming unit, and a transfer device. The toner image forming unit includes a charger, a latent image forming device, and a developing device, and is configured to form a test latent image pattern on a surface of the latent image bearer, and to develop the test latent image pattern into a test toner pattern. The test latent image pattern includes a plurality of test latent image parts partly offset from one another in a main scanning direction. The image forming apparatus also includes a developing current detector and a processor to detect uneven image density in the main scanning direction using the test latent image pattern, based on the developing current detected by the developing current detector, to adjust the uneven image density in the main scanning direction.

Abstract: An image forming apparatus includes an image carrier, an image forming unit, a density sensor, a gradation characteristic data generator, and a gradation corrector. The density sensor includes a low-pass filter to remove a high-frequency component of an output of the image density sensor. The gradation characteristic data generator forms a gradation correction pattern on the image carrier. The gradation correction pattern is a continuous gradation pattern including first and second patterns. The gradation characteristic data generator continuously detects image density of the continuous gradation pattern and background areas adjacent to the continuous gradation pattern to generate the gradation characteristic data. The gradation characteristic data generator forms a compensation pattern on the image carrier next to and continuous with a leading end of the first pattern in an image carrier rotational direction, to compensate for a response delay of the output of the density sensor due to the low-pass filter.

Abstract: An image forming apparatus includes a latent image bearer, a toner image forming unit, and a transfer device. The toner image forming unit includes a charger, a latent image forming device, and a developing device, and is configured to form a test latent image pattern on a surface of the latent image bearer, and to develop the test latent image pattern into a test toner pattern. The test latent image pattern includes a plurality of test latent image parts partly offset from one another in a main scanning direction. The image forming apparatus also includes a developing current detector and a processor to detect uneven image density in the main scanning direction using the test latent image pattern, based on the developing current detected by the developing current detector, to adjust the uneven image density in the main scanning direction.

Abstract: An image forming apparatus includes an image carrier, an image forming unit to form a multi-gradation image on the image carrier, a density detector to detect density of the multi-gradation image, a gradation characteristic data generator to generate gradation characteristic data, and a gradation corrector to correct image data of the multi-gradation image. The gradation characteristic data generator forms a gradation correction pattern on the image carrier via the image forming unit. The gradation correction pattern is a continuous gradation pattern including a first pattern having gradation levels from a maximum gradation level to a minimum gradation level and a second pattern having gradation levels from the minimum gradation level to the maximum gradation level.

Abstract: An image forming apparatus includes an image carrier, an image forming unit, a density sensor, a gradation characteristic data generator, and a gradation corrector. The density sensor includes a low-pass filter to remove a high-frequency component of an output of the image density sensor. The gradation characteristic data generator forms a gradation correction pattern on the image carrier. The gradation correction pattern is a continuous gradation pattern including first and second patterns. The gradation characteristic data generator continuously detects image density of the continuous gradation pattern and background areas adjacent to the continuous gradation pattern to generate the gradation characteristic data. The gradation characteristic data generator forms a compensation pattern on the image carrier next to and continuous with a leading end of the first pattern in an image carrier rotational direction, to compensate for a response delay of the output of the density sensor due to the low-pass filter.

Abstract: An image forming apparatus includes an image carrier, an image forming unit to form a multi-gradation image on the image carrier, a density detector to detect density of the multi-gradation image, a gradation characteristic data generator to generate gradation characteristic data, and a gradation corrector to correct image data of the multi-gradation image. The gradation characteristic data generator forms a gradation correction pattern on the image carrier via the image forming unit. The gradation correction pattern is a continuous gradation pattern including a first pattern having gradation levels from a maximum gradation level to a minimum gradation level and a second pattern having gradation levels from the minimum gradation level to the maximum gradation level.

Abstract: In an embodiment, a diffuse reflection output conversion method is executed in an apparatus detecting a plurality of gradation patterns. The apparatus includes a light emitter and light receiver, and detects specular reflection and diffuse reflection simultaneously. A region before specular reflection saturation is a region where the specular reflection component decreases and saturates at minimum level. A diffuse reflection detector is calibrated by: obtaining a diffuse reflection output resulting from an amount of attached powder at a border between the region before specular reflection saturation and the region after specular reflection saturation; calculating a ratio between the diffuse reflection output and a reference diffuse reflection output calculated in advance as a calibration coefficient; and multiplying a diffuse reflection output obtained from the gradation patterns by the calibration coefficient calculated at the calculating.

Abstract: A developing device for developing an electrostatic latent image on an image bearing member including a developer bearing member opposed to the image bearing member to bear thereon a developer including a toner and a magnetic carrier; a developer containing part to contain the developer to supply the developer to the developer bearing member; an agitating or feeding member to agitate or feed the developer in the developer containing part; a magnetic permeability sensor to measure magnetic permeability of the developer to determine toner concentration of the developer; a developer feeder; a feeding member to feed the developer to the developer containing part through the developer feeder; and a driver to drive the feeding member independently of the agitating or feeding member. The magnetic permeability sensor is arranged on the developer feeder.

Abstract: A developing device for developing an electrostatic latent image on an image bearing member including a developer bearing member opposed to the image bearing member to bear thereon a developer including a toner and a magnetic carrier; a developer containing part to contain the developer to supply the developer to the developer bearing member; an agitating or feeding member to agitate or feed the developer in the developer containing part; a magnetic permeability sensor to measure magnetic permeability of the developer to determine toner concentration of the developer; a developer feeder; a feeding member to feed the developer to the developer containing part through the developer feeder; and a driver to drive the feeding member independently of the agitating or feeding member. The magnetic permeability sensor is arranged on the developer feeder.

Abstract: In an embodiment, a diffuse reflection output conversion method is executed in an apparatus detecting a plurality of gradation patterns. The apparatus includes a light emitter and light receiver, and detects specular reflection and diffuse reflection simultaneously. A region before specular reflection saturation is a region where the specular reflection component decreases and saturates at minimum level. A diffuse reflection detector is calibrated by: obtaining a diffuse reflection output resulting from an amount of attached powder at a border between the region before specular reflection saturation and the region after specular reflection saturation; calculating a ratio between the diffuse reflection output and a reference diffuse reflection output calculated in advance as a calibration coefficient; and multiplying a diffuse reflection output obtained from the gradation patterns by the calibration coefficient calculated at the calculating.