Multi-Laser Scanner Focus Switching for High-Speed Conveyor Reading
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Solution Overview
Problem
Conventional scanners face issues with slow processing times and increased points of failure due to moving mechanical parts, which affect their reliability and efficiency in reading and decoding information from packages on a conveyor system.
Innovation Solution
A laser scanner system that employs multiple lasers with different focal points, controlled by a Field Programmable Gate Array (FPGA) to automatically determine which laser to activate based on distance and signal measurements, eliminating the need for moving focus mechanisms and enhancing processing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a moving focus mechanism is used to adjust the laser focal point, then the depth of field is increased, but the processing speed decreases and reliability deteriorates due to mechanical wear
Solution Approach 1:
The patent divides the scanning system into multiple independent laser sources, each with a fixed focal point at different distances. Instead of moving one laser's focus, the system segments the focusing function across multiple stationary lasers, eliminating mechanical movement while maintaining variable depth of field capability.
Solution Approach 2:
The patent replaces the mechanical focus adjustment mechanism with an electronic selection system controlled by a microprocessor. The microprocessor selectively activates appropriate lasers based on detected object distance, substituting mechanical focal adjustment with electronic control of multiple fixed-focus sources.
2Reliability
If multiple lasers are activated sequentially to cover different depths, then the depth of field is increased, but the scan rate decreases due to alternating activation
Solution Approach 1:
The patent implements preliminary action by pre-positioning multiple lasers at different focal distances before scanning begins. The system detects object distance in advance and pre-selects the appropriate laser, eliminating the need for alternating activation during the scanning process and maintaining high scan rates.
Solution Approach 2:
The patent introduces dynamic selection of lasers based on real-time distance measurements. The microprocessor continuously monitors object position and dynamically switches between lasers, ensuring the optimal laser is active at each moment, thereby maintaining both high scan rates and accurate focus.
3Area of stationary object
If an adjustable lens is used to change the focal point, then the depth of field is increased, but the system complexity and cost increase due to moving parts
Solution Approach 1:
The patent segments the focusing function into multiple independent laser sources with fixed focal points rather than using a single laser with an adjustable lens. This segmentation eliminates the need for complex lens adjustment mechanisms while achieving variable depth of field through selective laser activation.
Solution Approach 2:
The patent replaces the mechanical lens adjustment system with an electronic control system that selects from multiple fixed-focus lasers. This substitution eliminates moving mechanical parts in the optical path, reducing system complexity and cost while maintaining the ability to adjust focal depth.
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 system increases scan rates and reliability by automatically toggling between lasers, improving the field of view and depth of field, and reducing mechanical failures, enabling efficient decoding of codes on objects moving on a conveyor belt.
Implementation Method 1
A portion of the light that is reflected from the package is detected by the sensors
Implementation Method 2
detected by the sensors and converted into an electrical signal
Implementation Method 3
The two or more lasers may be focused at different distances inside a single scanner. The multiple foci may increase the depth of field for reading of images
Data Source
AI summary
Scanners, methods, and computer storage media having computer-executable instructions embodied thereon that process variable sized objects with high package pitch on a moving conveyor belt are provided. The scanners are laser scanners that include at least two laser diodes, sensors, and field programmable gate arrays processors. The at least two laser diodes have different focuses. Each diode generates a laser beam when excited by an activation signal and an appropriate modulation. The sensors within the laser scanner device measure light reflected from a target on the objects. The processors toggle activation among the at least two laser diodes based on measurements sensed from the light reflected from the target.