Abstract: An image forming apparatus includes an image forming unit, a first detector including a first light emitting device, a first mixed-light receiving device and a first diffuse reflection light receiving device, a second detector including a second light emitting device and a second mixed-light receiving device, and a concentration correction unit. The first mixed-light receiving device detects a mixed light including regular and diffuse reflection light reflected from a transport member. The first diffuse reflection light receiving device detects the diffuse reflection light. The second mixed-light receiving device detects the mixed light. The concentration correction unit conducts concentration correction using detection results of the first and second detectors.

Abstract: An optical writing device includes: a light source including arrays arranged in a main scanning direction, each array including light-emitting elements arranged in the main scanning direction; a correction-value holding unit to hold, correspondingly with a light-emitting element, a correction value for changing timing to read out pixel data stored in an image storage unit; and a light-source drive unit to drive the light source by reading out the stored pixel data stored, according to the correction value. The correction-value holding unit includes a first area for holding a first correction value corresponding to a first light-emitting element located at an end of an array and a second area for holding a second correction value corresponding to a second light-emitting element other than the first light-emitting element, the first holding area being larger than the second holding area.

Abstract: An image forming apparatus including at least one latent image carrier, an image forming unit to form a toner image on the at least one latent image carrier based on image data, a transfer body onto which the toner image formed on the at least one latent image carrier is transferred in one or more valid image ranges, a non-image range determiner to determine a non-image range on a surface of the transfer body onto which the toner image is not transferred, a surface detector to detect the surface of the transfer body in the non-image range, and a toner determiner to determine whether or not toner is present in the non-image range based on a result detected by the surface detector.

Abstract: An image forming apparatus for which a first mode using toners of plural colors including a black toner and a second mode using only the black toner can be set, includes a first printing cumulatively counting part that cumulatively counts a first number of pages for which image forming has been executed by using the toners of plural colors; a first printing determining part that determines whether the first number of pages counted by the first printing cumulatively counting part has exceeded a threshold; and a correction control part that controls not to execute a correcting process for image forming that uses the toners of plural colors but to execute a correcting process for image forming that uses only the black toner, when the second mode has been set in a case where the first printing determining part has determined that the first number of pages has exceeded the threshold.

Abstract: A position error correcting method includes forming an image-forming condition determination pattern on an endless transport unit transported in a first direction, the image-forming condition determination pattern including plural unit patterns having different unit-area attached toner amounts and arranged in the first direction; detecting a detection limit pattern having the minimum detectable unit-area attached toner amount from the unit patterns; calculating an image-forming condition of the detection limit pattern; forming a position error correction pattern on the endless transport unit in the first direction in accordance with the image-forming condition; and correcting a position error of a toner image formed on the endless transport unit by plural image forming units, using the position error correction pattern, wherein the position error is corrected with respect to a second direction perpendicular to the first direction.

Abstract: An image forming apparatus includes an endless belt, image forming units disposed along the endless belt, an image skew obtaining unit, a recording medium skew obtaining unit, and a skew correction unit. The image forming unit includes an image carrying member to form a toner image. A correction pattern formed of toner image is formed on the endless belt. The image skew obtaining unit obtains skew of toner image based on a detection result of the correction pattern. The recording medium skew obtaining unit obtains skew of the recording medium based on detection of an edge of the recording medium. The skew correction unit corrects an image forming position of the toner image on the image carrying member using correction data prepared from the obtained skew for the correction pattern and the obtained skew for the recording medium.

Abstract: A single-pipe cylinder type reformer for manufacturing a hydrogen-rich reformed gas by steam-reforming a hydrocarbon-based crude fuel such as town gas, natural gas, or LPG or an alcohol and a reformer used with a polymer electrolyte fuel cell. The reformer has an upright outer circular cylinder, a circular cylinder, radially spaced, concentrically inside the outer cylinder, a circular intermediate cylinder concentrically located between the outer and inner cylinders, and a circular radiation cylinder concentrically located inside the inner cylinder. A burner is fixed to one end portion of the reformer and is located in the center of the radiation cylinder. A plurality of laminar annular flows including a reforming catalyst are formed between the inner and intermediate cylinders and between the intermediate and outer cylinders. End portions of the outer and inner cylinders located opposite to where the burner is fixed are sealed with different cover plates that form a double-bottom structure.

Abstract: A single-pipe cylinder type reformer for manufacturing a hydrogen-rich reformed gas by steam-reforming a hydrocarbon-based crude fuel such as town gas, natural gas, or LPG or an alcohol and a reformer used with a polymer electrolyte fuel cell. The reformer has an upright outer circular cylinder, a circular cylinder, radially spaced, concentrically inside the outer cylinder, a circular intermediate cylinder concentrically located between the outer and inner cylinders, and a circular radiation cylinder concentrically located inside the inner cylinder. A burner is fixed to one end portion of the reformer and is located in the center of the radiation cylinder. A plurality of laminar annular flows including a reforming catalyst are formed between the inner and intermediate cylinders and between the intermediate and outer cylinders. End portions of the outer and inner cylinders located opposite to where the burner is fixed are sealed with different cover plates that form a double-bottom structure.

Abstract: A hydrogen producing apparatus for producing hydrogen on an industrial scale by steam reforming reactions and separating hydrogen using a hydrogen-permeable membrane, including nested outer (14), intermediate (18) and inner (20) cylinders, a combustion burner (44) disposed toward the inner hollow chamber of the inner cylinder (20), a catalyst layer (A) in the annulus (30) between the intermediate (18) and inner (20) cylinders, hydrogen-permeable tubes (32) disposed in the catalyst layer (A-30), and sweep gas supply tubes (34) in the hydrogen-permeable tubes (32). The raw material gas is fed to the catalyst layer (A) and is converted into hydrogen at a high temperature produced by the burner (44), the produced hydrogen permeates the hydrogen-permeable tubes (32) which selectively separate and collect the hydrogen, and the permeated hydrogen flows with the sweep gas out of the apparatus through the outlet (52) for the sweep tubes (34).