Multi-Cavity Laser Diode for Raster Scanning Line Multiplication
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Solution Overview
Problem
Existing bi-optic laser scanners are limited by the number of beam splitters and reflectors, which restricts the number of scan lines in the raster pattern, leading to increased manufacturing costs and reduced scanning speed and read rates.
Innovation Solution
A method and apparatus using a multi-cavity visible laser diode (VLD) with multiple laser cavities that are sequentially activated and driven in synchronism with a rotating scanning element to produce multiple raster-type laser scanning lines, eliminating the need for additional moving parts and allowing for the generation of multiple laser beams that are transformed into a multiple raster-type laser scanning pattern.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple beam splitters and reflectors are used to generate multiple scan lines, then the number of raster lines increases, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines multiple laser cavities (first, second, and third cavities) into a single integrated laser source, replacing the traditional separate beam splitters and reflectors system. This merging of multiple light-generating functions into one compact device reduces overall system complexity while maintaining the capability to produce multiple scan lines.
Solution Approach 2:
The laser source is designed with multiple cavities that can independently generate laser beams, making a single device perform the function of multiple beam splitters and reflectors. Each cavity can be selectively activated to produce different scan lines, providing multi-functionality within a unified structure.
2Productivity
If multiple beam splitters and reflectors are used to generate multiple scan lines, then the number of raster lines increases, but manufacturing cost increases
Solution Approach 1:
By integrating multiple laser cavities into a single source, the patent eliminates the need for multiple separate optical components (beam splitters and reflectors), thereby reducing the number of parts that need to be manufactured, assembled, and calibrated, which directly lowers manufacturing cost.
Solution Approach 2:
The patent uses multiple laser cavities that replicate the laser generation function within a single device, allowing one compact unit to replace multiple external optical components, simplifying manufacturing while achieving the same functional result of generating multiple scan lines.
3Ease of manufacture
If the number of beam splitters and reflectors is limited, then manufacturing cost is reduced, but scanning speed and read rates decrease
Solution Approach 1:
The integration of multiple laser cavities enables the system to generate multiple scan lines simultaneously from a single source, maintaining high scanning speed and read rate without requiring multiple external optical components, thus avoiding the manufacturing cost penalty.
Solution Approach 2:
The patent employs periodic switching between different laser cavities (first, second, third cavities) to generate sequential scan lines, enabling high-speed scanning through time-division multiplexing without requiring all optical paths to be physically present simultaneously.
4Productivity
If multiple laser cavities are sequentially activated, then multiple laser beams are generated with improved scanning performance, but the control complexity increases
Solution Approach 1:
The patent incorporates feedback mechanisms to synchronize the periodic activation of multiple laser cavities with the rotating polygon mirror, ensuring that each cavity fires at the precise moment its beam should be scanned, thereby managing control complexity through active coordination.
Solution Approach 2:
The systematic periodic activation of laser cavities in synchronization with the polygon mirror rotation creates a predictable, rhythmic operation pattern that simplifies timing control compared to arbitrary activation sequences, making the control system more manageable despite multiple components.
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
This approach enhances scanning speed and read rates while simplifying the design and reducing manufacturing costs, enabling efficient scanning of bar code symbols, including high-density 2D stacked bar codes, by modulating the multi-cavity laser diode to generate multiple laser beams at different times and directing them onto a rotating polygon scanning element.
Implementation Method 1
A method and apparatus for multiplying laser scanning lines in a raster-type laser scanning pattern by modulating a multi-cavity laser diode to generate multiple laser beams
Implementation Method 2
directing the output laser beam upon a rotating polygon scanning element
Data Source
AI summary
A method of and apparatus for generating a multiple raster-type scanning pattern by modulating a multi-cavity laser diode in such a way that it sequentially generates different laser beams synchronously during different laser scanning cycles, while the output laser beams are directed incident upon a rotating polygonal laser scanning element. The system does not require additional moving parts beyond the rotating polygon scanning element so as to reduce complexity and simplify construction of the laser scanning mechanism.