Abstract: A tape library system includes a plurality of cartridge cells for accommodating a plurality of tape cartridges respectively, a tape drive for writing and reading data to and from the tape cartridge inserted therein, a diagnosis drive for diagnosing the tape cartridge inserted therein, an cartridge carriage mechanism for inserting and ejecting the tape cartridge into and from the tape drive and the diagnosis drive, and a diagnosis controller for controlling the cartridge carriage mechanism to load the tape cartridge into the diagnosis drive and for controlling the diagnosis drive to diagnose the tape cartridge inserted therein.

Abstract: An image forming apparatus includes plural image holding members; an intermediate transfer material; a transfer unit that transfers the toner images onto a recording medium; a density control toner image creating unit that creates a density control toner image at a constant position on each of the image holding members; a density detection unit that detects density of the density control toner image transferred onto a non-image region; and a creation timing control unit that controls timing of creating the density control toner image to create the density control toner image in the non-image region of the intermediate transfer material at a position where a length obtained by integrally multiplying the length obtained by adding the non-image region to the image region along the moving direction of the intermediate transfer material becomes equal to a length obtained by integrally multiplying the circumferential length of the image holding member.

Abstract: An image forming apparatus includes an image carrier on which an electrostatic latent image is formed, a rotary developing device having N developer carriers, where N defines a total number of developer carriers, the N developer carriers carrying developers to develop the electrostatic latent image, and the rotary developing device moves the N developer carriers to a development position opposite to the image carrier, and a toner concentration sensor that measures toner concentrations of the developers carried in the developer carriers. A measurement position of the toner concentration sensor is set on a second virtual straight line with the second virtual straight line having a first angle or an angle that is double the first angle toward a first virtual straight line on a rotation orbit of the rotary device, and the first virtual straight line connects a rotation center of the rotary developing device and the development position.

Abstract: A virtual tape system includes an actual tape device having a magnetic tape which stores data. The virtual tape system includes a virtual tape storage device which stores data stored in the actual tape device as a virtual tape volume, first computers to be connected to a host computer which instructs a storing of data in the actual tape device, and a reading of data from the actual tape device, control an interface with the host computer, second computers which control the virtual tape volume of the virtual tape storage device, third computers which control a writing of the data into the actual tape device, and a local disk controller which stores the data in one of storage devices mounted one in each of the first computers, each of the second computers, and each of the third computers.

Abstract: An image forming apparatus comprises: a rotary unit having a plurality of development devices provided around a rotary shaft, the development device including a constituent unit, wherein the plurality of the development devices move to a development position where the development devices sequentially oppose an image carrier by rotation of the rotary unit, and the development device in the development position develops an electrostatic latent image on the image carrier, a state detection unit that is disposed at a position above a circumference of the rotary unit, the position being different from the development position and that detects at least one of a state of the development devices and a state of the constituent unit of the development devices; and a rotation control unit that controls the rotary unit so as to perform rotation of the rotary unit for sequentially moving the development devices to the development position and rotation of the rotary unit for sequentially moving the development devices t

Abstract: The computer system is capable of improving performance, reliability and redundancy. The computer system comprises: a plurality of server computers having different functions, the server computers being mutually connected by communication lines; a standby server computer being connected to each of the server computers by the communication lines, the standby server computer being capable of performing the function of each of the server computers; a detection unit for detecting an abnormal state of each of the server computers; and a take-over unit for controlling the standby server computer to take over the action of the abnormal server computer when the abnormal state of the abnormal server computer is detected by the detection unit.

Abstract: An image forming apparatus includes an image carrier on which an electrostatic latent image is formed, a rotary developing device having N developer carriers, where N defines a total number of developer carriers, the N developer carriers carrying developers to develop the electrostatic latent image, and the rotary developing device moves the N developer carriers to a development position opposite to the image carrier, and a toner concentration sensor that measures toner concentrations of the developers carried in the developer carriers. A measurement position of the toner concentration sensor is set on a second virtual straight line with the second virtual straight line having a first angle or an angle that is double the first angle toward a first virtual straight line on a rotation orbit of the rotary device, and the first virtual straight line connects a rotation center of the rotary developing device and the development position.

Abstract: An image forming apparatus includes an image carrier on which an electrostatic latent image is formed, a rotary developing device having N developer carriers on a rotation orbit and moving the N developer carriers to a development position opposite to the image carrier, and a toner concentration sensor that measures toner concentrations of the developers. A measurement position of the toner concentration sensor is set on a second virtual straight line having a first angle toward a first virtual straight line that connects a rotation center of the rotary developing device and the development position. The N developer carriers are placed in turn in an order at the same angular interval as the first angle, and an angular interval between the N-th and first developer carriers is set to a second angle greater than the first angle.

Abstract: An image forming apparatus includes a rotary unit that has a rotary shaft, and a plurality of development devices each of which has a constituent unit, the development devices provided around the rotary shaft; and a plurality of state detection units that detects at least one of states of the development devices and states of the constituent unit; wherein the rotary unit is rotated so that the development devices sequentially pass a development position facing a photosensitive member; wherein when any of the development devices is located at the development position, the development device makes an electrostatic latent image on the photosensitive member visible; and wherein each of the state detection units detects at least one of the development devices and the states of the constituent unit during a single stop of rotation of the rotary unit.

Abstract: An image forming apparatus includes an image carrier on which an electrostatic latent image is formed, a rotary developing device having N developer carriers on a rotation orbit and moving the N developer carriers to a development position opposite to the image carrier, and a toner concentration sensor that measures toner concentrations of the developers. A measurement position of the toner concentration sensor is set on a second virtual straight line having a first angle toward a first virtual straight line that connects a rotation center of the rotary developing device and the development position. The N developer carriers are placed in turn in an order at the same angular interval as the first angle, and an angular interval between the N-th and first developer carriers is set to a second angle greater than the first angle.

Abstract: An image forming apparatus includes: an image carrier on which an electrostatic latent image is to be formed; a rotary development unit having a plurality of developer carriers that carry a developer used for developing the electrostatic latent image, the developer including toner, the plurality of the developer carriers being sequentially moved to a development position opposing to the image carrier, to switch a development color; and a toner concentration detection unit that detects the concentration of toner of the developer carried by one of the developer carriers located at the development position.

Abstract: An image forming apparatus includes an image carrier on which an electrostatic latent image is formed, a rotary developing device having N developer carriers on an rotation orbit and moving the N developer carriers to a development position opposite to the image carrier, and a toner concentration sensor that measures toner concentrations of the developers. A measurement position of the toner concentration sensor is set on a second virtual straight line having a first angle toward a first virtual straight line that connects a rotation center of the rotary developing device and the development position. The N developer carriers are placed in turn in an order at the same angular interval as the first angle, and an angular interval between the N-th and first developer carriers is set to a second angle greater than the first angle.

Abstract: An image forming apparatus includes a rotary unit having a plurality of development devices provided around a rotary shaft, the development device having a constituent unit, wherein: a plurality of the development devices sequentially move to a development position, where the development devices oppose an image carrier by rotation of the rotary unit, and a development device located at the development position develops an electrostatic latent image on the image carrier; each of the plurality of development devices has a state detection unit that detects at least one of a state of the development device and a state of a constituent unit of the development device; and the state detection unit of each of the development devices performs state detection when the development device having the state detection unit is located at the development position.

Abstract: An image forming device includes an image forming section that forms an image in accordance with predetermined image formation conditions; a storage section that stores a target darkness of a standard image; a measurement section that measures a physical quantity for specifying the darkness of the image formed by the image forming section; a user calibration section that causes the image forming section to form the standard image in response to an instruction input by a user, causes the measurement section to measure the physical quantity when that standard image is formed, and if there is a discrepancy between the darkness of the standard image specified by the measurement of the physical quantity and the target darkness stored in the storage section, adjusts the image formation conditions such that this discrepancy is eliminated; a manual darkness adjustment section that changes the image formation conditions to content that is specified by the user; a control section that, when the user calibration section

Abstract: An image forming apparatus includes: an image carrier on which an electrostatic latent image is to be formed; a rotary development unit having a plurality of developer carriers that carry a developer used for developing the electrostatic latent image, the developer including toner, the plurality of the developer carriers being sequentially moved to a development position opposing to the image carrier, to switch a development color; and a toner concentration detection unit that detects the concentration of toner of the developer carried by one of the developer carriers located at the development position.

Abstract: An image forming apparatus comprises: a rotary unit having a plurality of development devices provided around a rotary shaft, the development device including a constituent unit, wherein the plurality of the development devices move to a development position where the development devices sequentially oppose an image carrier by rotation of the rotary unit, and the development device in the development position develops an electrostatic latent image on the image carrier, a state detection unit that is disposed at a position above a circumference of the rotary unit, the position being different from the development position and that detects at least one of a state of the development devices and a state of the constituent unit of the development devices; and a rotation control unit that controls the rotary unit so as to perform rotation of the rotary unit for sequentially moving the development devices to the development position and rotation of the rotary unit for sequentially moving the development devices to a

Abstract: An image forming apparatus includes an image carrier on which an electrostatic latent image is formed, a rotary developing device having N developer carriers on an rotation orbit and moving the N developer carriers to a development position opposite to the image carrier, and a toner concentration sensor that measures toner concentrations of the developers. A measurement position of the toner concentration sensor is set on a second virtual straight line having a first angle toward a first virtual straight line that connects a rotation center of the rotary developing device and the development position. The N developer carriers are placed in turn in an order at the same angular interval as the first angle, and an angular interval between the N-th and first developer carriers is set to a second angle greater than the first angle.

Abstract: An image forming apparatus includes a rotary unit that has a rotary shaft, and a plurality of development devices each of which has a constituent unit, the development devices provided around the rotary shaft; and a plurality of state detection units that detects at least one of states of the development devices and states of the constituent unit; wherein the rotary unit is rotated so that the development devices sequentially pass a development position facing a photosensitive member; wherein when any of the development devices is located at the development position, the development device makes an electrostatic latent image on the photosensitive member visible; and wherein each of the state detection units detects at least one of the development devices and the states of the constituent unit during a single stop of rotation of the rotary unit.

Abstract: An image forming apparatus includes a rotary unit having a plurality of development devices provided around a rotary shaft, the development device having a constituent unit, wherein: a plurality of the development devices sequentially move to a development position, where the development devices oppose an image carrier by rotation of the rotary unit, and a development device located at the development position develops an electrostatic latent image on the image carrier; each of the plurality of development devices has a state detection unit that detects at least one of a state of the development device and a state of a constituent unit of the development device; and the state detection unit of each of the development devices performs state detection when the development device having the state detection unit is located at the development position.

Abstract: An image forming apparatus that prepares a toner patch including a predetermined gradation area percentage on an image support to detect a developing concentration. An optical sensor detects reflected light from the background of the image support and reflected light from the toner patch prepared on the image support. The reflected light detected by the optical sensor is then controlled in response to the gradation area percentage of the prepared toner patch.