Image forming apparatus and laser scanning unit and polygon mirror thereof

Abstract

An image forming apparatus includes a photoconductor, a laser scanning unit to scan a beam across the photoconductor to form an electrostatic latent image on the photoconductor, a developing unit to apply a developer to the photoconductor having the electrostatic latent image formed thereon to form a visible image on the photoconductor, and a transferring unit to transfer the visible image, formed on the photoconductor, to a print medium. The laser scanning unit includes a light source to generate a beam according to an image signal, a polygon mirror including a plurality of reflection surfaces to deflect the beam, generated by the light source, in the main scanning direction, the reflection surfaces being aspherical to correct an aberration of the beam to converge the beam, deflected in the main scanning direction, on the photoconductor, and a motor to rotate the polygon mirror.

Description

technical field [0001] Aspects of the present invention relate to an image forming apparatus, and more particularly, to an image forming apparatus that forms an image by laterally scanning a beam of light on a photoreceptor, and a laser scanning unit and a polygon mirror thereof. Background technique [0002] In general, an image forming device is a device that prints a black-and-white image or a color image on a printing medium (for example, paper) according to an image signal. Typical examples of such image forming apparatuses are laser printers, inkjet printers, copiers, multifunction printers, and facsimile machines. An image forming apparatus forms an image using, for example, an electrophotographic process in which a light beam is scanned across a photoreceptor to form an electrostatic latent image on the photoreceptor, and a developer is applied to the photoreceptor, or using, for example, an inkjet process In order to form a visible image on the photoreceptor, and t...

AI Technical Summary

Problems solved by technology

[0006] However, in the conventional laser scanning unit disclosed in US Patent No. 7,057,781, the scanning optics must be assembled precisely so that the two lenses are precisely arranged without error

If either of the two lenses is inaccurately arranged due to an assembly error, the light beam cannot be accurately converged on the photoreceptor, thereby deteriorating image quality

As a result, the assembly process is very troublesome

[0007] In addition, conventional laser scanning units have a large number of lenses, so when the frame on which the lenses are mounted is deformed due to heat generated by various parts of the imaging device, there is a high possibility of distortion of the optical path

This distortion of the optical path degrades image quality

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