A pixel clock generating device includes a high-frequency clock generator, a comparer, a pixel clock generator, and a value switcher. The high-frequency clock generator is configured to generate a high-frequency clock. The comparer is configured to measure a time interval between a leading-end synchronizing signal and a trailing-end synchronizing signal in a main scanning and calculate an error between the time interval and a target value. The pixel clock generator is configured to generate a pixel clock based on the high-frequency clock and a pixel clock frequency and correct the pixel clock based on the error. The value switcher, including a plurality of groups of values with which the pixel clock is generated, is configured to switch between the plurality of groups of values according to a switching signal after the trailing-end synchronizing signal is inputted, the comparer calculates the error, and the pixel clock generator corrects the pixel clock.

An image forming apparatus that corrects a print position of an image using an optimum reference side of a sheet when performing print position adjustment. Image data is converted based on conversion conditions. An image on a sheet is formed based on the converted image data. On the sheet, the image forming unit forms a test image for detecting a misalignment of a position of an image to be formed on a first surface of the sheet and a position of an image to be formed on a second surface, which is different from the first surface, of the sheet. Read data is acquired which is read from the test image and output from a reading device, and the conversion conditions are generated based on the read data and a selected reference position of the sheet.

An image forming apparatus includes an acquiring unit configured to acquire atmosphere pressure in the installation place of the image forming apparatus, photoconductors, light sources configured to radiate laser light, and a polygon mirror configured to be rotatable. The polygon mirror exposes the photoconductors by reflecting the laser light toward the photoconductors while rotating. The image forming apparatus further includes a control device configured to control rotation of the polygon mirror. The control device outputs an enable signal for allowing the image forming apparatus to perform printing, if rotation of the polygon mirror is stabilized after start of the rotation, and advances the timing of outputting the enable signal as the atmosphere pressure increases.

An image forming apparatus includes: a conveying path on which a recording medium is conveyed; an image capturer that includes a light source and radiates light from the light source to capture the recording medium being conveyed at different timings to generate at least two images including a first image and a second image; and a movement amount calculator that calculates a movement amount of the recording medium between capturing timings of the first and second images, wherein the movement amount calculator: calculates an index distance which is a distance in a conveying direction of a pattern formed by reflected light from the recording medium; calculates a ratio between the index distance and a reference distance used for comparison with the index distance; and calculates a movement amount of the recording medium between the capturing timings of the first and second images.

A device detects at least one position of at least a part of a printing material while the printing material is transported in a printing machine. The device includes an optical sensor for establishing a distance between a printing machine component and the printing material. The distance established by the optical sensor is temperature-compensated by a computer.

An image forming apparatus which is capable of reducing a load on a data bus therein when controlling an image reading apparatus depending on its image processing capability. When acquired identification information about the image forming apparatus is included in a clock control table 600, a clock frequency for controlling hardware of the image reading apparatus in accordance with the clock control table 600, while setting the clock frequency therefor to a default setting of the clock control table 600 when the acquired identification information is not included in the clock control table 600, wherein a minimum value of clock frequencies in the clock control table 600 is set as the default setting of the clock control table 600.

An image forming apparatus includes an acquiring unit configured to acquire atmosphere pressure in the installation place of the image forming apparatus, photoconductors, light sources configured to radiate laser light, and a polygon mirror configured to be rotatable. The polygon mirror exposes the photoconductors by reflecting the laser light toward the photoconductors while rotating. The image forming apparatus further includes a control device configured to control rotation of the polygon mirror. The control device outputs an enable signal for allowing the image forming apparatus to perform printing, if rotation of the polygon mirror is stabilized after start of the rotation, and advances the timing of outputting the enable signal as the atmosphere pressure increases.

The optical scanning device includes a storage unit configured to store information on a scanning time of laser light and an emitted position of the laser light in a sub-scanning direction, the laser light measured on a plane. A scanning time for forming one scanning line is set based on the information on the measured scanning time and the measured emitted position, which is stored in the storage unit, and a radius of a photosensitive drum. This allows a magnification error in a main scanning direction to be reduced with an inexpensive configuration while realizing downsizing of an apparatus.

A recording apparatus includes a head including a wire and performing recording on a medium by allowing the wire to strike the medium, a temperature detection unit that detects a temperature of the head, a driving circuit for driving the wire, and a control unit that controls an energization state of the driving circuit. The control unit switches the energization state of the driving circuit between an ON state and an OFF state at each time determined by the control unit, based on the temperature detected by the temperature detection unit such that a current flowing in the driving circuit is kept constant, when the head performs recording on the medium.

A control device includes an image-formation command section and a first reception section. The image-formation command section commands an image forming section to form multiple latent images based on one input image onto an image bearing member in accordance with different light emission patterns by using a light source including multiple light emitting members, develop the latent images, and output the multiple developed images to a medium. The first reception section receives a designation by a user with respect to one of the multiple light emission patterns after the multiple images are output. Each light emission pattern indicates which of the multiple light emitting members included in the light source is to emit light.