Aiming Laser Intensity Control for Optical Code Detection
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Solution Overview
Problem
Imaging readers struggle to detect aiming patterns in bright ambient light conditions without violating human eye exposure laser safety limits, leading to difficulties in selecting the desired optical code from multiple codes within the field of view.
Innovation Solution
Aiming laser intensity is increased only during brief exposure periods during the aiming mode, with decreased intensity outside these periods, and pulsed to enhance pattern detection while maintaining safety standards, allowing improved contrast and visibility of the aiming pattern.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Difficulty of detecting and measuring
If laser intensity is increased to enhance aiming pattern detection in bright ambient light, then detection capability is improved, but human eye exposure safety limits are violated
Solution Approach 1:
The laser operates in periodic pulsed mode during the exposure time period, switching between high intensity (during exposure) and low or zero intensity (during non-exposure periods). This periodic action allows the aiming pattern to be detected with high contrast during the brief exposure window while limiting cumulative eye exposure to safe levels over time.
Solution Approach 2:
The laser intensity is dynamically adjusted based on the operational phase: high intensity during the exposure time period for optimal pattern detection, and low or zero intensity outside this period for safety. This dynamic control resolves the contradiction by making intensity adaptive rather than static.
2Object-affected harmful factors
If laser intensity is decreased to maintain safety standards, then eye exposure safety is ensured, but aiming pattern visibility and detection are reduced
Solution Approach 1:
By concentrating laser emission into periodic pulses during the exposure time period, the system achieves high instantaneous intensity for visibility while maintaining low average intensity for safety. The pattern is brightest when the shutter is open and detection is occurring.
Solution Approach 2:
The laser intensity parameter is changed dynamically between high and low states. During the exposure time period, intensity is increased to improve pattern brightness and detection. Outside this period, intensity is decreased to ensure safety compliance.
3Difficulty of detecting and measuring
If continuous high intensity laser is used for aiming pattern visibility, then pattern detection is improved, but energy consumption increases and safety limits are exceeded
Solution Approach 1:
The laser operates periodically rather than continuously, emitting high intensity pulses only during the exposure time period when detection is occurring. This reduces overall energy consumption while maintaining detectability during the critical measurement window.
Solution Approach 2:
The laser provides excessive intensity only when needed (during exposure) rather than continuously. This partial action approach concentrates energy delivery to the essential moment of detection, reducing total energy consumption while achieving the required detectability.
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
Enhances detection and capture of the aiming pattern without exceeding laser safety limits, ensuring the desired optical code can be selected and read even in challenging lighting conditions.
Implementation Method 1
an aiming assembly including a laser for emitting a laser beam having a variable intensity, and optics for generating an aiming pattern from the laser beam during an aiming mode
Implementation Method 2
an imager including an array of solid-state sensors for detecting and capturing the image of the aiming pattern and the code over a field of view by exposure over an exposure time period during the aiming mode
Data Source
AI summary
An image capture system for, and a method of, reading an optical code during a reading mode, comprise an aiming assembly including a laser for emitting a laser beam having a variable intensity, and for generating an aiming pattern from the laser beam during an aiming mode prior to the reading mode, and an imager for detecting and capturing an image of the aiming pattern and the code over a field of view by exposure over an exposure time period during the aiming mode, and for detecting and capturing an image of the code over the field of view during the reading mode. A controller is operative for controlling the intensity of the laser beam during the aiming mode by increasing the intensity of the laser beam during the exposure time period to enhance detection and capture of the aiming pattern by the imager, and by decreasing the intensity of the laser beam frame outside the exposure time period for user safety.