Hybrid Image Sensor Array for Specular Reflection Barcode Decoding
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Solution Overview
Problem
Optical readers face decoding failures due to specular reflection from shiny surfaces such as metal, glass, and laminated plastic, which saturate the image sensor array and hinder performance.
Innovation Solution
An optical reader with a hybrid monochrome and color image sensor array that includes a subset of light polarizing pixels with filter elements to attenuate specularly reflected light, and separate reset control lines for monochrome and color pixels to reduce cross-talk and enhance decoding performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional color image sensor array is used, then picture taking performance is maintained, but specular reflection causes saturation and decoding failures
Solution Approach 1:
The image sensor array is segmented into multiple types of pixels: monochrome pixels for high dynamic range capture and color pixels for color information. This segmentation allows the system to handle specular reflection by using monochrome pixels that can detect reflected light intensity without saturation, while color pixels maintain picture taking performance.
Solution Approach 2:
Different regions of the image sensor array have different properties - monochrome pixels are distributed throughout the array to provide specular reflection resistance, while color pixels are positioned to maintain overall color image quality. This local differentiation of pixel properties resolves the contradiction between decoding reliability and harmful reflection factors.
2Object-affected harmful factors
If monochrome pixels are added to the sensor array, then specular reflection resistance improves, but device complexity increases
Solution Approach 1:
The patent merges monochrome pixels and color pixels into a single hybrid image sensor array. This combining approach allows the system to benefit from both monochrome pixels' resistance to specular reflection and color pixels' ability to capture color information, while avoiding the need for separate imaging systems that would increase complexity.
Solution Approach 2:
The hybrid pixel array provides multi-functionality - monochrome pixels handle specular reflection and high dynamic range tasks, while color pixels handle color image capture. Both pixel types work together in a unified array, making the system universally capable of handling both bar code decoding on shiny surfaces and picture taking without requiring separate devices.
3Measurement precision
If light polarizing pixels are used to attenuate polarized light, then specular reflection errors are reduced, but manufacturing complexity increases
Solution Approach 1:
The patent changes the optical parameters of specific pixels by incorporating light polarizing elements (such as wavelength selective color filter elements) into the pixel structure. This parameter modification allows the pixels to selectively attenuate polarized light at specular angles, improving measurement precision while using standard semiconductor fabrication techniques to keep manufacturing feasible.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces specular reflection errors, enabling high-quality bar code decoding and color image capture, comparable to an all-monochrome sensor for decoding and an all-color sensor for image quality, respectively.
Implementation Method 1
the light polarizing pixels can be light polarizing pixels having a light polarizing filter element that significantly attenuates polarized light rays generated from an appropriately polarized light source and reflected at a specular angle
Implementation Method 2
Light rays emanating from a reader that are projected on a highly reflective shiny surface of a substrate may be substantially entirely reflected directly onto a reader image sensor array
Data Source
AI summary
There is provided in one embodiment an apparatus having an image sensor array. In one embodiment, the image sensor array can include monochrome pixels and color sensitive pixels. The monochrome pixels can be pixels without wavelength selective color filter elements. The color sensitive pixels can include wavelength selective color filter elements.