An image is read from a recording medium via first and second optical imaging systems disposed such that respective reading regions partially overlap each other in a principal scanning direction on a reading surface. A sum of distances over which first and second images captured by the first and second optical imaging systems, respectively, are displaced in the principal scanning direction with respect to a reference point included in a region in which the reading regions overlap each other is calculated. First and second distances, over which the first and second images are displaced in the principal scanning direction, respectively, are calculated using the sum and first and second reading angles at which the first and second optical imaging systems, respectively, read the reference point. Positions of the first image and the second image in the principal scanning direction are corrected using the first distance and the second distance, respectively.

An image reading device includes at least one reference portion that is provided in a reading area of a reading unit provided with a moving mechanism, a memory unit that stores, as an initial value, positional data of the reference portion that is read by the reading unit, an acquisition unit that reads the positional data of the reference portion and acquires a displacement amount of the read positional data from the initial value, and an error handling unit that performs error handling when the displacement amount exceeds a predetermined value.

An image forming apparatus includes an image forming unit, an image reading unit, an image inspecting unit and a history generating unit. The image forming unit forms an image on a sheet. The image reading unit reads a sheet face on which the image is formed, thereby generating a scan image. The image inspecting unit compares the generated scan image with a normal image to detect an error in the scan image. When the image inspecting unit detects the error, the history generating unit generates detection information on the detected error and embeds the generated detection information in the scan image, thereby generating a history image.

An image reading device includes at least one reference portion that is provided in a reading area of a reading unit provided with a moving mechanism, a memory unit that stores, as an initial value, positional data of the reference portion that is read by the reading unit, an acquisition unit that reads the positional data of the reference portion and acquires a displacement amount of the read positional data from the initial value, and an error handling unit that performs error handling when the displacement amount exceeds a predetermined value.

An image forming apparatus includes an image forming unit, an image reading unit, an image inspecting unit and a history generating unit. The image forming unit forms an image on a sheet. The image reading unit reads a sheet face on which the image is formed, thereby generating a scan image. The image inspecting unit compares the generated scan image with a normal image to detect an error in the scan image. When the image inspecting unit detects the error, the history generating unit generates detection information on the detected error and embeds the generated detection information in the scan image, thereby generating a history image.

An image forming apparatus includes an image forming unit, an image reading unit, an image inspecting unit and a history generating unit. The image forming unit forms an image on a sheet. The image reading unit reads a sheet face on which the image is formed, thereby generating a scan image. The image inspecting unit compares the generated scan image with a normal image to detect an error in the scan image. When the image inspecting unit detects the error, the history generating unit generates detection information on the detected error and embeds the generated detection information in the scan image, thereby generating a history image.

A method and system of controlling at least one printbar in a printing system are described. The printing system has one or more of printbars distributed along a media transport. A first image including a reference pattern is generated on a print medium with a first printbar. A pattern is then detected on the print medium. The reference pattern and the detected pattern are used to determine a position of the first image relative to a second printbar. This position is used to configure nozzle data for a second image to be generated on the print medium by the second printbar.

A method and system of controlling at least one printbar in a printing system are described. The printing system has one or more of printbars distributed along a media transport. A first image including a reference pattern is generated on a print medium with a first printbar. A pattern is then detected on the print medium. The reference pattern and the detected pattern are used to determine a position of the first image relative to a second printbar. This position is used to configure nozzle data for a second image to be generated on the print medium by the second printbar.

An image forming apparatus includes a reading unit, an image processing unit configured to perform image processing based on an adjustment condition, an image forming unit configured to form an image on a sheet based on image data on which the image processing is performed, and a controller configured to control the image forming unit to form a first measurement image on a first side of a sheet, control the image forming unit to form a second measurement image on a second side of the sheet, control the reading unit to obtain reading data related to the sheet on which the first and the second measurement images are formed, and generate the adjustment condition based on the reading data and a correction condition, wherein the controller generates the correction condition based on a reading result of the first side and a reading result of the second side.

A method and system of controlling at least one printbar in a printing system are described. The printing system has one or more of printbars (160, 190) distributed along a media transport. A first image including a reference pattern (240A, 240B) is generated on a print medium (150) with a first printbar (160). A detector (180) then detects a pattern on the print medium. The reference pattern and the detected pattern are used to determine a position of the first image relative to a second printbar (190). This position is used to configure nozzle data for a second image to be generated on the print medium by the second printbar.