In an optical scanning device, an outer wall closest to a circumscribed circle of a rotating polygon mirror has a space in a position facing to a position of a reflection surface of the rotating polygon mirror in an axial direction of a rotating shaft. A part of a cover is provided in a position farther from the circumscribed circle than the outer wall so as to close the space, when the optical scanning device is viewed in a direction perpendicular to the axial direction of the rotating shaft.

A method for manufacturing optical scanning systems by which plural optical scanning systems with different effective scanning widths can be manufactured by changing a polygon mirror alone is provided. The method includes the steps of designing a first scanning optical system using a first polygon mirror corresponding to a first value of effective scanning width; designing a second scanning optical system provided with a second polygon mirror corresponding to a second value of effective scanning width, the second value being smaller than the first value, wherein a reference point of deflection is located at the position of the reference point of deflection of the first scanning optical system; and adjusting a size and a position of the scanning lens so as to adjust a lateral magnification in a cross section in the sub-scanning direction of the imaging optical system.

An apparatus configured to fly a light-absorbing material, includes a unit configured to irradiate a light-absorbing material absorbing light with a laser beam corresponding to a light absorption wavelength of the light-absorbing material to fly the light-absorbing material. When a preceding beam radiation region and a following beam radiation region overlap, the following beam radiation region is irradiated with the laser beam such that a beam centroid position is outside the preceding beam radiation region.

An image forming apparatus includes a unit configured to perform image forming operation, a unit board in the unit, a wiring configured to be connected to the unit board, and a control board configured to be connected to the unit board with the wiring and control the unit. The unit board includes a connector to which the wiring is to be connected. A length of the connector in a longitudinal direction of the connector is longer than a length of the unit board in a widthwise direction of the unit board, and the longitudinal direction of the connector intersects the widthwise direction of the unit board.

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.

An article includes a body member and a detachable member detachably attached to the body member. One of the body member and the detachable member includes a cover portion having an engaging portion on an inner wall face of the cover portion. The other includes a covered portion that is covered with the cover portion and has an engaged portion on an outer wall face of the covered portion. The engaging portion and the engaged portion are configured to be disengaged by warping the cover portion so that the cover portion displaces to an outer wall face side of the cover portion. The one of the body member and the detachable member includes a finger-applying-position indicator at a position deviated from a portion corresponding to the cover portion, on an outer wall face of the one. The finger-applying-position indicator indicates a position to be applied with fingers of a user.

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 includes a photosensitive member and a scanning unit including a light source, a rotatable polygonal mirror, and a sensor. The image forming apparatus includes setting of an operation in a first mode and setting of an operation in a second mode. The image forming apparatus further comprises, a surface identifying portion and a correction data storing portion configured to prestore correction data including first correction data for a first rotational speed and second correction data for a second rotational speed. Positional deviation in a main scan direction of laser light is corrected on the basis of the first correction data or the second correction data.

In a housing, an installation surface (44g) of an image forming lens unit (42L) is formed at a higher position by a level difference than an installation surface (44f) of a polygon motor (41), and when viewed from a rotation axis direction of a polygon mirror unit (40), a diameter (r) of a circumscribed circle passing each apex of the polygon mirror unit (40) is larger than an outer diameter (R) of a rotor part (41a) of the polygon motor (41).

An approach for forming a multi-colored image on a substrate that includes a thermochromic material capable of producing at least two different colors is disclosed. Individually selected pixels of the thermochromic material that correspond to the image are heated to predetermined temperatures. Each predetermined temperature corresponds to a predetermined color shift of the thermochromic material. While the individually selected pixels are being heated, an area that includes the individually selected pixels is flooded with an amount of UV radiation sufficient to at least partially polymerize the thermochromic material. A color of each individually selected pixel is determined by a predetermined temperature to which the pixel is heated and the amount of UV radiation to which the pixel is exposed.