US 6,637,656 B2Granted

Optical reading apparatus and optical reading method

AssigneeKonica Corporation

InventorsTatsuji Kurogama, Makoto Banno, Nobuyuki Baba

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Abstract

The present invention concerns an optical reading apparatus and an optical reading method for obtaining objective information by reading a subject and processing the read information through an arithmetic processing. The optical reading apparatus includes a light source to irradiate a light flux onto a subject; a photo-receiving element to receive a reflected light or a transmitted light of the light flux irradiated onto the subject, and to generate signals based on an opt-electronic converting action; an arithmetic processing section to apply an arithmetic processing to the signals, in order to detect information of the subject; and a calculating section to apply a calculating processing, for reducing noise components caused by optical factors, to the signals generated by the photo-receiving element, in order to obtain output signals in which noise components are reduced, before the arithmetic processing section applies the arithmetic processing to the signals.

Claims17

Dependent claims

An apparatus for optically reading information residing on a subject which has a reference plane, said information being formed by at least one of a convex area protruded from said reference plane and a concave area caved into said reference plane, said apparatus comprising:

a light source to irradiate a light flux onto said subject;
a photo-receiving element to receive either a reflected light or a transmitted light coming from said subject when said light flux is irradiated onto said subject, wherein said photo-receiving element is capable of detecting a photo-receiving position so as to generate original signals in response to variations of said photo-receiving position through a photoelectronic conversion process, and said original signals include informational signals representing said information and a noise component caused by either reflectance variations or transmittance variations distributing over said subject;
and
a noise-elimination calculating section to reduce said noise component included in said original signals by applying a noise-elimination calculating operation to said original signals, so as to output processed signals in which a level of said noise component is reduced lower than that included in said original signals,
wherein said noise-elimination calculating operation includes the steps of:
finding a first centroid of light totally projected onto said photo-receiving element, from said original signals generated by said photo-receiving element;
finding a second centroid of light caused by either said reflectance variations or said transmittance variations distributing over said subject, from said original signals generated by said photo-receiving element;
and
obtaining said processed signals by subtracting said second centroid of light from said first centroid of light in said original signals.

6 more elements

A method for optically reading information residing on a subject which has a reference plane, said information being formed by at least one of a convex area protruded from said reference plane and a concave area caved into said reference plane, comprising the steps of:

irradiating a light flux emitted from light source onto said subject;
receiving either a reflected light or a transmitted light coming from said subject with a photo-receiving element, which is capable of detecting a photo-receiving position;
generating original signals in response to variations of said photo-receiving position through a photoelectronic conversion process, said original signals including informational signals representing said information and a noise component caused by either reflectance variations or transmittance variations distributing over said subject;
and
applying a noise-elimination calculating operation to said original signals, so as to reduce said noise component included in said original signals and to output processed signals in which a level of said noise component is reduced lower than that included in said original signals,
wherein said noise-elimination calculating operation includes the steps of:
finding a first centroid of light totally projected onto said photo-receiving element, from said original signals generated by said photo-receiving element;
finding a second centroid of light caused by either said reflectance variations or said transmittance variations distributing over said subject, from said original signals generated by said photo-receiving element;
and
obtaining said processed signals by subtracting said second centroid of light from said first centroid of light In said original signals.

7 more elements

Dependencies are inferred from the claim text.