An optical member that refracts a light beam to diverge or focus the light beam, includes: at least three pairs of opposing surfaces. Each of the three pairs of opposing surfaces include a lens. Curvatures of the lenses at one side surfaces of the respective three pairs of surfaces are all the same, or curvatures of the lenses at one side surfaces of respective pairs of at least two pairs of the three pairs of surfaces are different from each other, and respective shortest distances between optical axes of the lenses at the one side surfaces of respective pairs of the at least two pairs of surfaces, and reference sides which are each any one of respective sides surrounding surfaces including the lenses are different from each other.

An example device includes a U-shaped body to be placed around a guide on which a scanner carriage is to be guided. A fixed leg of the U-shaped body is attached to a linearly translatable scanner carriage. A free leg of the U-shaped body is not attached to the scanner carriage and has inward facing ribs. The ribs on the free leg of the U-shaped body are positioned to come into contact with the guide to align the scanner carriage with the guide.

An image reading apparatus including a reading unit comprising a photodetector configured to read an image information on a sheet, and a projecting portion, a case storing the photodetector therein, the case comprising a transparent portion configured to transmit light to be received by the photodetector, and a portion defining an opening through which the projecting portion is projected outward from the case, and an elastic portion provided to fill a space where the projecting portion is not present in the opening. The case movably stores the photodetector within a range where the projecting portion is movable in the opening.

A method for capturing an image of an object includes guiding a scanning beam along a scanning trajectory over the object using a scanner, with the scanning movement being periodic in a direction. The scanning movement is sampled at a first sampling frequency for detecting and capturing a current position of the scanner as position values and radiation from the object is captured as captured sampling values at a second sampling frequency. Current values of the amplitude and the phase of the scanning movement are calculated. A current amplitude, phase and/or frequency and future changes in the amplitude, phase and/or frequency over time are calculated. An image grid is set, with grid elements being assigned the sampling values based on times at which the scanning beam crosses or will cross at least one boundary of the grid elements.

An image reading device includes a placement portion in which a placement surface on which an original document is placed is formed, an imaging portion that is arranged above the placement surface and images the original document, a support portion of which a base end portion is attached to an apparatus main body and that supports the imaging portion in a part on a tip end side, an adjustment portion for adjusting a position of the imaging portion with respect to the placement surface, and a covering portion that covers the adjustment portion.

An optical member that refracts a light beam to diverge or focus the light beam, includes: at least three pairs of opposing surfaces. Each of the three pairs of opposing surfaces include a lens. Curvatures of the lenses at one side surfaces of the respective three pairs of surfaces are all the same, or curvatures of the lenses at one side surfaces of respective pairs of at least two pairs of the three pairs of surfaces are different from each other, and respective shortest distances between optical axes of the lenses at the one side surfaces of respective pairs of the at least two pairs of surfaces, and reference sides which are each any one of respective sides surrounding surfaces including the lenses are different from each other.

The present disclosure provides a light scanning unit and an electronic image forming apparatus including the light scanning unit. The light scanning unit includes a light source, a first optical unit, an optical deflector, and a second optical unit. The light source includes at least two light-emitting points; the at least two light-emitting points are distributed along a straight line; and an angle between an extension direction of a distribution line thereof and a main scanning direction or a secondary scanning direction of the light scanning unit includes an acute angle, where the main scanning direction is perpendicular to the secondary scanning direction. The first optical unit is configured to collimate at least two light beams emitted from the light source along the main scanning direction and to focus the at least two light beams emitted from the light source along the secondary scanning direction.

An image forming apparatus includes an image bearer, an image forming section, an image density difference detector, and control circuitry. The image forming section is configured to form a gradation image pattern on a surface of the image bearer. The gradation image pattern includes gradation images having different image densities stepwise in a sub-scanning direction. The image density difference detector is configured to detect image density differences in a main scanning direction of the gradation images. The control circuitry is configured to execute an image density difference correction mode that corrects the image density differences in the main scanning direction based on detection results detected by the image density difference detector.

An example device includes a U-shaped body to be placed around a guide on which a scanner carriage is to be guided. A fixed leg of the U-shaped body is attached to a linearly translatable scanner carriage. A free leg of the U-shaped body is not attached to the scanner carriage and has inward facing ribs. The ribs on the free leg of the U-shaped body are positioned to come into contact with the guide to align the scanner carriage with the guide.

An image forming apparatus including a polygon mirror that deflects a light beam, the image forming apparatus includes: an optical sensor arranged such that the light beam deflected by the polygon mirror enters the optical sensor; and a hardware processor that measures an output level of the optical sensor and calculates, as a remaining life of the polygon mirror, an operation time of the polygon mirror to when the output level becomes a threshold value in a case of assuming that the output level ongoingly changes at a rate of change over time that is a change amount of the output level per unit operation time of the polygon mirror, using the measured output level.