Information reading method and device, signal capturing method for information reading device, band limiting device therefor, timing point amplitude extracting method therefor, and signal processing

Abstract

There is provided a method of reading information which makes it possible to suppress the size of hardware and a price thereof and to improve an S / N ratio of a reading signal and reading resolution, wherein even if depth of field for reading is enlarged or a concave / convex portion or a blurred portion is left on the reading face, reading precision can be improved. The method includes steps of acquiring from a medium, a signal containing binary digit information having a predetermined information length and a one-dimensional arrangement, extracting information concerning an elemental unit length of the information length of the binary digit information from the acquired signal, and reading a ratio of the binary digit information to the information length based on the extracted elemental unit length information.

Description

technical field [0001] The present invention relates to, for example, like a barcode scanner for reading information contained in a barcode, which acquires a signal including binarized information arranged in 1 dimension from a medium having a given information length, and converts it in an integer ratio Appropriate information reading method and device for reading width information represented by binary amplitude information included in the obtained signal, signal obtaining method of information reading device, band limitation processing method, timing point amplitude Extraction method and signal processing method, read signal processing device, and read signal processing method and processing device. Background technique [0002] Conventionally, in the field of commercial distribution, a barcode attached to a product etc. is read by a barcode reading device (barcode scanner), and information about the product such as the price and name of the product is registered in a reg...

AI Technical Summary

Problems solved by technology

[0039] (1) In order to be able to process the barcode signal from the shallow to the deep of the reading depth L, there is a problem in the circuit on the receiving side: Since the frequency characteristics of a wide frequency band are required, the wider the frequency band, the more noise is generated. The larger the amount, the lower the signal-to-noise ratio (S / N)

[0040] (2) As a device, since it is necessary to read thin barcodes, it is necessary to reduce the diameter of the laser beam (beam)

In this case, in barcodes with irregularities on the paper surface or blurred bars, the irregularities may be scanned as a signal, and the black-and-white boundary signal is generated in a place other than the original place, resulting in misrecognition of the black-and-white border. s reason

[0041] (3) Because the laser is used for scanning, the deeper the reading depth, the wider the radius of the beam (beam), and the poorer the resolution, there may be obstacles to the reading of thin and narrow labels.

[0044] (1) In order to maintain the accuracy of the bar width, it is necessary to increase the sampling frequency of the A / D converter (at least increase the read minimum bar width by about 10 times or more), thus, because the signal frequency band is increased, it is necessary to increase the sampling frequency caused by the above factors The noise or circuit noise becomes sensitive, and false recognition of the black and white edges of the bar width will occur

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