Optical Scanner Amplitude Tuning for Low Contrast Code Reading

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing optical information code reading methods face challenges in achieving high reading accuracy for low contrast optical information code images, particularly after image recording on thermoreversible recording media with low reflectivity backgrounds, which results in poor bar code and QR code reading accuracy in physical distribution lines.

Innovation Solution

An optical information code reading method that employs an amplitude tuning unit to correct and store the detected amplitude level of reflectivity, allowing the scanner to read the code under optimal conditions, even with low contrast images, by adjusting the amplitude of the electrical signals received from the thermoreversible recording medium.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If near infrared laser beams are used to record images on thermoreversible recording medium, then non-contact recording and erasing can be performed, but the background of the recording medium becomes colored and reflectivity decreases

Engineering Contradiction:
Improvenon-contact recording capabilityVSAvoidbackground reflectivity
Core Design Contradiction:
Extent of automationVSIllumination intensity

Solution Approach 1:

The patent changes the wavelength parameter of the laser beam from near-infrared to visible light range (630-700 nm), which eliminates the coloring effect on the recording medium background while maintaining the ability to record and erase images. This parameter change resolves the contradiction by selecting a wavelength that does not cause background discoloration.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a visible light laser beam that replicates the functional capabilities of near-infrared laser beams (image recording and erasing) without producing the harmful side effect of background coloring. The visible light laser creates an optical copy of the near-infrared laser's functionality while avoiding its detrimental effects on reflectivity.

Inventive Principle:
Principle #26Copying

2Productivity

If the bar code scanner reads the thermoreversible recording medium immediately after image recording, then throughput is improved, but reading accuracy decreases due to low contrast

Engineering Contradiction:
Improvereading throughputVSAvoidreading accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by pre-adjusting the amplitude tuning parameters of the bar code scanner before reading the low-contrast image. The amplitude tuning unit is configured in advance to detect and correct the reduced contrast levels that occur immediately after laser recording, enabling accurate reading without requiring waiting time for contrast improvement.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback through the amplitude tuning unit that continuously monitors the reflectivity amplitude of the recording medium and automatically adjusts detection parameters. This feedback mechanism compensates for the low contrast condition immediately after image recording, maintaining high reading accuracy while enabling immediate reading operation.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3117365B1Optical information code reading method
Publication Date: 2019.08.07 RICOH CO LTD
  • EP3117365B1 patent drawingFigure 1~2A
  • EP3117365B1 patent drawingFigure 2B~3B
  • EP3117365B1 patent drawingFigure 4~5

AI summary

An optical information code reading method, including reading an optical information code image by an optical information code scanner immediately after the optical information code image has been recorded onto an information recording medium, wherein the optical information code scanner includes an amplitude tuning unit configured to correct a detected amplitude level of reflectivity from the information recording medium on which the optical information code image has been recorded and to store the corrected detected amplitude level, and wherein the optical information code scanner reads the optical information code image in a state in which the optical information code scanner has read the information recording medium on which the optical information code image has been recorded, and the amplitude tuning unit has determined and stored a detected amplitude level optimum for reading.