A laser imager for a printing system, comprising a plurality of independently addressable surface emitting lasers arranged in a linear array on a common substrate chip and including a common cathode and a dedicated control channel associated with an address trace line for each laser of the plurality of independently addressable surface emitting lasers, and optical elements arranged in a linear lens array configured to capture and focus light from the plurality of independently addressable surface emitting lasers onto a imaging member, wherein the plurality of independently addressable surface emitting lasers arranged in a linear array and the optical elements arranged in a linear lens array operate together to image the imaging member.

An optical print head comprises a first light emitting element row, a second light emitting element row, a lens array, a first drive circuit and a second drive circuit. The first light emitting element row includes the arrangement of first light emitting elements. The second light emitting element row includes second light emitting elements arranged in parallel with the first light emitting element row. The lens array concentrates light emitted by the first light emitting elements and the second light emitting elements. The first drive circuit drives each first light emitting element with an identical first current value. The second drive circuit drives each second light emitting element with an identical second current value different from the first current value.

An image forming apparatus includes: a correction unit configured to correct a tone of each pixel in first image data in accordance with an image height on a photosensitive member, and output second image data; a halftone processing unit configured to determine exposed regions of pixels in an image by applying halftone processing to the second image data; and a scanning unit configured to form a latent image by scanning the photosensitive member with light that changes in scanning speed in accordance with an image height based on the exposed regions of the pixels. The scanning unit is further configured to perform partial exposure with respect to the pixels based on the exposed regions of the pixels, the partial exposure exposing partial regions of the pixels to light unlike entire exposure that exposes entire regions of the pixels to light.

A semiconductor laser driver and an image forming apparatus incorporating the semiconductor laser driver. The semiconductor laser driver includes a light source including a plurality of laser-beam source units disposed in a sub-scanning direction that serves as a group direction, the laser-beam source units having a plurality of groups arranged in a main scanning direction, each of the laser-beam source units emitting a laser beam of a light quantity dependent upon a driving current, a shading corrector to correct, according to at least one shading correction value, the driving current given to the laser-beam source units for each of the groups, and a light quantity adjuster to adjust the driving current according to a light-quantity adjustment value for the laser-beam source units. The image forming apparatus includes a semiconductor laser drive circuit, and the semiconductor laser driver that serves as the semiconductor laser driver.

An optical print head comprises a first light emitting element row, a second light emitting element row, a lens array, a first drive circuit and a second drive circuit. The first light emitting element row includes the arrangement of first light emitting elements. The second light emitting element row includes second light emitting elements arranged in parallel with the first light emitting element row. The lens array concentrates light emitted by the first light emitting elements and the second light emitting elements. The first drive circuit drives each first light emitting element with an identical first current value. The second drive circuit drives each second light emitting element with an identical second current value different from the first current value.

Provided is a method for flattening a laser-based image of a curved book page, which is applicable to a scanning platform and an image acquisition device and a laser generation device fixed above the scanning platform. The flattening method includes the following steps of: opening a book on a horizontally arranged scanning platform, and emitting a laser beam to a curved book page to be scanned, the laser beam forming a plurality of laser lines parallel on the curved book page; acquiring a horizontal image of the curved book page having the parallel laser lines, and acquiring a 2D planar coordinate (x, y) of each pixel on the laser line in the horizontal image; calculating, according a y-coordinate in the 2D planar coordinate, a y-coordinate of an intersection line of the laser beam and the scanning platform, and an intersection angle of the laser beam and the scanning platform, and by means of a tangent function, a height of each pixel on the laser line, i.e., an actual spatial height; calculating actual spatial heights of all pixels on each laser line, i.e., z-coordinates, to acquire a 3D spatial curve of the laser line; constructing, using the curve, an actual 3D curved surface of the photographed book page; and flattening the 3D curved surface after pixel value transfer to complete flattening of the curved book page.

Provided is a method for flattening a laser-based image of a curved book page, which is applicable to a scanning platform and an image acquisition device and a laser generation device fixed above the scanning platform. The flattening method includes the following steps of: opening a book on a horizontally arranged scanning platform, and emitting a laser beam to a curved book page to be scanned, the laser beam forming a plurality of laser lines parallel on the curved book page; acquiring a horizontal image of the curved book page having the parallel laser lines, and acquiring a 2D planar coordinate (x, y) of each pixel on the laser line in the horizontal image; calculating, according a y-coordinate in the 2D planar coordinate, a y-coordinate of an intersection line of the laser beam and the scanning platform, and an intersection angle of the laser beam and the scanning platform, and by means of a tangent function, a height of each pixel on the laser line, i.e., an actual spatial height; calculating actual spatial heights of all pixels on each laser line, i.e., z-coordinates, to acquire a 3D spatial curve of the laser line; constructing, using the curve, an actual 3D curved surface of the photographed book page; and flattening the 3D curved surface after pixel value transfer to complete flattening of the curved book page.

A natural frequency measuring device includes a receiving unit and a measuring unit. The receiving unit receives information of an image formed on a recording medium with vibrations of different frequencies provided to a member used to form the image. The measuring unit measures a natural frequency of the member from a frequency response characteristic using a misregistration amount of the image represented by the information of the image received by the receiving unit.

An optical print head comprises a first light emitting element row, a second light emitting element row, a lens array, a first drive circuit and a second drive circuit. The first light emitting element row includes the arrangement of first light emitting elements. The second light emitting element row includes second light emitting elements arranged in parallel with the first light emitting element row. The lens array concentrates light emitted by the first light emitting elements and the second light emitting elements. The first drive circuit drives each first light emitting element with an identical first current value. The second drive circuit drives each second light emitting element with an identical second current value different from the first current value.

An image forming apparatus can reduce degradation of the line quality in an output image by a simple method while maintaining the stability of the density characteristics of the output image, and a control method therefor. To accomplish this, in accordance with the amount of change, from a reference density value, of a density value measured from a test pattern image formed on a photosensitive drum, the image forming apparatus according to the invention creates LUT_2 for correcting a laser output signal value corrected using correction LUT_1. The image forming apparatus performs correction using LUT_1 and LUT_2 for developing colors other than a predetermined low-brightness developing color, whereas for the predetermined low-brightness developing color, it performs correction using LUT_1 and laser light amount correction instead of correction using LUT_2.