Optical Imaging Device for High-Speed Code Scanning
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Solution Overview
Problem
Existing vision or camera-based systems for scanning optical codes lack sufficient scan rates, leading to missed or partially imaged codes, especially in applications where objects are moving quickly.
Innovation Solution
An optical imaging device that uses a method to read optical codes by focusing an imaging path along an optical axis, generating an illumination pattern, folding the imaging path using reflective surfaces, and sensing the object with an area sensor that uses only a predetermined number of lines of pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a vision or camera based system is used to scan optical codes, then the device complexity is reduced and ease of operation is improved, but the scanning rate is insufficient leading to missed or partially imaged codes
Solution Approach 1:
The patent segments the sensor array into multiple independent line sensors that can be read out simultaneously or in rapid succession. This segmentation allows the system to maintain the simplicity of camera-based imaging while achieving laser-scanner-level scanning rates by processing multiple lines in parallel or rapid sequence, thereby resolving the contradiction between ease of operation and scanning rate.
Solution Approach 2:
The patent implements periodic illumination using pulsed light sources that synchronize with the line sensor readout. This periodic action allows the system to capture multiple lines during a single object passage, effectively increasing the scanning rate without requiring continuous high-speed readout of the entire sensor array, thus maintaining ease of operation while improving productivity.
2Length of moving object
If the opening angle of the field of view is increased to cover the same field of view as laser systems, then the mounting distance can be reduced, but the scan rate decreases due to the larger area requiring imaging
Solution Approach 1:
The patent divides the large field of view into multiple smaller line segments that can be imaged and processed independently. This segmentation allows the system to use a larger opening angle for mounting flexibility while maintaining high scan rates by reading out individual lines in rapid succession or parallel, rather than requiring the entire large field to be captured and processed as a single image.
Solution Approach 2:
The patent transitions from two-dimensional area sensor imaging to one-dimensional line sensor imaging, adding the dimension of temporal sequencing. By imaging lines sequentially in the time dimension rather than simultaneously in space, the system achieves both large field of view coverage and high scan rates, resolving the contradiction between mounting distance and scan rate.
3Area of stationary object
If laser output power is increased to extend reading distance and field of view, then the field of view and reading distance are improved, but the device becomes subject to regulatory limitations and safety concerns
Solution Approach 1:
The patent replaces the laser-based mechanical scanning system with a camera-based imaging system that uses non-coherent light sources. This substitution eliminates the need for high-power lasers and their associated safety and regulatory issues, while achieving comparable or superior field of view and reading distance through the use of area sensors and optical imaging, thereby resolving the contradiction between field of view and harmful factors.
4Productivity
If rotating or vibrating mirrors are used in laser scanning systems to generate a moving spot, then the scanning rate is improved, but the reliability and lifespan decrease due to wear and tear on moving parts
Solution Approach 1:
The patent replaces the mechanical mirror scanning system with a stationary sensor array that electronically scans the field of view. This substitution eliminates all moving mechanical parts, including rotating or vibrating mirrors, thereby maintaining high scanning rates through electronic readout while dramatically improving reliability and lifespan by removing the sources of mechanical wear and failure.
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 significantly increases the scanning rate of the optical imaging system, allowing for faster and more accurate capture of optical codes, even in applications with limited space between the device and the object.
Implementation Method 1
folding the imaging path using reflective surfaces
Implementation Method 2
focusing an imaging path along an optical axis using a lens
Implementation Method 3
The plurality of illumination devices are light emitting diodes
Data Source
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Figure 3A~3B
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AI summary
The present invention relates to optical imaging devices and methods for reading optical codes. The image device comprises a sensor, a lens, a plurality of illumination devices, and a plurality of reflective surfaces. The sensor is configured to sense with a predetermined number of lines of pixels, where the predetermined lines of pixels are arranged in a predetermined position. The lens has an imaging path along an optical axis. The plurality of illumination devices are configured to transmit an illumination pattern along the optical axis, and the plurality of reflective surfaces are configured to fold the optical axis.