Registers – Coded record sensors – Particular sensor structure
Reexamination Certificate
2001-06-12
2003-10-28
Lee, Michael G. (Department: 2876)
Registers
Coded record sensors
Particular sensor structure
C235S462270, C235S454000, C235S472010
Reexamination Certificate
active
06637656
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to methods and apparatus for optically reading information, and specifically relates to 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.
Conventionally, when deriving the objective information from optical information read optically, the objective information is detected or recognized by applying a processing-operation, such as an image-analyzing operation, etc., to signals obtained by reading the optical information. For instance, the barcode recognition, the character recognition, the shape recognition, etc. are included in the above operation.
Specifically, noise components caused by an optical mechanism are included in opt-electronic conversion results outputted by the optical reading apparatus, which comprises a light source, a photo-receiving element and a calculating means, and irradiates a light bundle emitted from the light source onto the subject, and opt-electronically converts its reflected light or its transmitted light with the photo-receiving element, and then, detects the information of the subject by applying the an arithmetic processing to the signals converted opt-electronically.
For instance, in case that different kinds of printed patterns or the like exist on the surface of the subject when the light bundle emitted from the light source is irradiated onto the subject to detect a concave or a convex of the surface of the subject with its reflected light, the signals opt-electronically converted by the photo-receiving element include noise components, caused by an optical mechanism, which is overlapped with the concave or convex information as a detecting subject.
As mentioned above, when noise components caused by optical factors is larger than the opt-electronically converted signals, etc., and, for instance, characters and numerals formed in either the convex or the concave are detected/recognized by detecting the aforementioned convex or concave formed on the surface of the subject, and various kinds of patterns printed or residing on the surface of the subject works as noise components caused by optical factors, such the noise components considerably impede an accurate reading action for the information, which include deviations of the convex or the concave as a detecting object.
Incidentally, explaining according to the aforementioned example, in case that the information, being a detecting object of the subject, is at least one of the convex or the concave formed on the surface of the subject, and the noise components caused by optical factors, such as the distribution of reflecting rates or the distribution of transmitting rates, exist on the surface of the subject, when detecting them with a reflected light or a transmitting light, the noise components, caused by such as colors and density patterns, etc., which influences to the reflecting rate or the transmitting rate on the surface of the subject, are integrated with the detected signals including the information of the convex or the concave being the detecting object.
Accordingly, in case that the noise components are the optical information caused by optical factors, when optically reading the information being the detecting object, it has been very difficult to separate both of them or to remove only the noise components from the detected signals.
Conventionally, methods for eliminating fine noises caused by electronic factors or noises, having a frequency of 50-60 Hz and generated by a fluorescent lamp, have been well known. Further, although, other than the above methods, a method for discriminating figures and characters by applying an arithmetic filtering processing to two-dimensional information (image data) thereafter, when the noise components, overlapping with the signals itself generated by the photo-receiving element, are large, it is impossible to accurately detect/recognize the information being a objective detecting object, even if the CPU in the later stage applies an arithmetic processing for its image analysis.
SUMMARY OF THE INVENTION
The present invention is attained in view of the abovementioned problems in conventional optical reading apparatus and optical reading methods. In a method and an apparatus, in which objective information are obtained by optically reading the subject and applying arithmetic processing, it is an object of the present invention to reduce the influence of the noise components caused by optical factors and to improve the accuracy of the necessary information being a detecting object.
Accordingly, to overcome the cited shortcomings, the abovementioned object of the present invention can be attained by optical reading apparatus and methods described as follow.
(1) An optical reading apparatus, comprising: 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.
(2) The optical reading apparatus of item 1, wherein the photo-receiving element is capable of detecting a photo-receiving position, and the optical reading apparatus detects a distribution of deviations of at least one of a convex or a concave on the subject, based on the variation of the photo-receiving position.
(3) The optical reading apparatus of item 2, wherein the noise components caused by optical factors, arises from a distribution of light-reflecting rates or light-transmitting rates of the subject.
(4) The optical reading apparatus of item 3, wherein the calculating section finds a first centroid of the light on the photo-receiving element, and a second centroid of the light on the photo-receiving element, caused by the distribution of light-reflecting rates or light-transmitting rates of the subject, from the signals generated by the photo-receiving element, and the output signals, in which the noise components are reduced, are obtained by applying the calculating processing, for reducing the noise components caused by optical factors, to the signals generated by the photo-receiving element by subtracting the second centroid of the light from the first centroid of the light.
(5) The optical reading apparatus of item 4, wherein the calculating section finds the second centroid of the light from a total quantity of the light on the photo-receiving element.
(6) The optical reading apparatus of item 5, wherein the photo-receiving element is a one-dimensional PSD (Position Sensitive Detector), and the calculating section finds the first centroid of the light from two electronic current values or two voltage values outputted from both ends of the one-dimensional PSD, and the calculating section finds the second centroid of the light from a sum of two electronic current values or two voltage values outputted from both ends of the one-dimensional PSD.
(7) The optical reading apparatus of item 6, wherein the calculating section comprises a memory to store the two electronic current values or the two voltage values outputted from the both ends of the one-dimensional PSD, and the calculating section finds the first centroid of the light from two electronic current values or two voltage values stored in the memory, and the memory also stores the sum of the two electronic current values or the two voltage values, and the calculating section finds the second centroid of the light from the sum stored in the memory.
(8) The optical reading apparatus of ite
Baba Nobuyuki
Banno Makoto
Kurogama Tatsuji
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Konica Corporation
Lee Michael G.
Sanders Allyson
LandOfFree
Optical reading apparatus and optical reading method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical reading apparatus and optical reading method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical reading apparatus and optical reading method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3116079