Image forming optical system, image reader using image forming optical system, and image writer

Abstract

An image forming optical system for forming a high-quality image by determining a most suitable design condition while ensuring a uniform and adequate amount of light and preventing ghost. In this image forming optical system having a slit, the factors to remove the stray light include the inclination of the direction of a lens array, the slit width, the lens pitch, the angle of view, and height of the light-shielding wall. The position of the slit, the thickness of the lens, and width of the lens line do not affect the stray light removal but affect the brightness. If the system has no slit, the essential factors to remove the stray light include the height of the light-shielding wall and the lens pitch. The thickness of the lens and width of the lens line do not affect the stray light removal but affects the brightness.

Description

technical field [0001] The present invention relates to an image forming optical system that transmits an image to a linear imaging area using a resin erect lens array, and an image reading device and an image writing device using the image forming optical system. Background technique [0002] As described in JP-A-5-167778, the imaging optical system includes a light source, a lens, a sensor array (CCD, etc.), and a housing (casing) for accommodating them. [0003] The image forming optical system used in the image reading device has a structure in which the original is irradiated with light emitted from a light source, the light reflected from the original is converged by a lens, and captured by a sensor array. When the reflected light from the document surface enters the lens and is picked up by the sensor array, flare or ghosting may occur due to the configuration of the optical system, and this may degrade the image quality. [0004] In order to prevent the occurrence o...

AI Technical Summary

Problems solved by technology

[0011] However, in this method, although the optimum condition can be determined for the width of the slit, it is not possible to determine the optimum condition for elements other than the width of the slit, so it is not possible to design all of the above-mentioned elements in the most suitable condition. Image forming optical system for ghost removal condition

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