Image sensor unit and image reading device using the same

Abstract

An image sensor unit, comprising: a light guide body (16) for reflected light, which is used to irradiate a banknote S with light from a light source (15) for reflected light from a reflected light exit surface (16b); body (23), which is used to irradiate the banknote S with the light from the light source (24) for transmitted light from the transmitted light exit surface (23b); the rod lens array (18), which is used to make the reflected light from the banknote S and / or imaging of the transmitted light after passing through the banknote S; the light receiving element (19), which is used to receive the light collected by the rod lens array (18); and the frame (13), which has a light guide capable of accommodating reflected light The receiving part (17) of the body (16). A part of the housing part (17) has a light shielding part (25) protruding from the reflected light exit surface (16b) of the light guide for reflected light (16) toward the optical axis Z side of the rod lens array (18), and is light shielded. The part (25) has a positioning reference surface (26) for positioning the light guide body (16) for reflected light. It can reduce the influence of stray light and improve the accuracy of reading images.

Description

technical field [0001] The present invention relates to an image sensor unit used in an image reading device such as a copier, an image scanner, or a facsimile, and an image reading device using the image sensor unit. In particular, it relates to an image reading device for judging the authenticity of recording media such as banknotes and securities. Background technique [0002] As a representative image reading device of this type, in particular, among image reading devices for judging the authenticity of banknotes and the like, for example, a device described in Patent Document 1 is known. [0003] prior art literature [0004] patent documents [0005] Patent Document 1: Japanese Patent Laid-Open No. 2007-116590 Contents of the invention [0006] The problem to be solved by the invention [0007] However, in the conventional technology disclosed in the above-mentioned Patent Document 1, in a state where there is no document when reflective reading is performed (fo...

AI Technical Summary

Problems solved by technology

There is a problem that this stray light (reflected light described later) becomes a noise component in the output of the image sensor unit, which reduces the difference between the output (signal component) and the noise component caused by stray light when there is an original document, And make the contrast less clear and reduce the accuracy of reading the image, etc.

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