Hybrid Autofocus System for Data Readers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hybrid autofocus systems for data readers fail to provide optimal performance in environments with multiple moving items, as they rely on phase detection technology and are not robust enough to handle complex fields-of-view effectively.
Innovation Solution
A hybrid autofocus system that combines active and passive autofocus techniques, using a rangefinder for distance measurement and image sensor for contrast detection, allowing for quick and precise focus adjustment, and integrating motion-activation capabilities to enhance data reading performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If active autofocus systems are used for fast distance measurement, then focusing speed is improved, but measurement precision deteriorates in complex fields-of-view with multiple moving items
Solution Approach 1:
The patent combines active autofocus (rangefinder-based) and passive autofocus (image-based contrast detection) into a hybrid system. The rangefinder provides fast initial distance estimation, while the image processor performs contrast detection to refine focus accuracy. This merging allows the system to achieve both rapid focusing and high precision in complex fields-of-view with multiple items at varying distances.
2Measurement precision
If passive autofocus systems are used for precise focus determination, then measurement precision is improved, but focusing speed deteriorates
Solution Approach 1:
The system performs preliminary distance measurement using the active rangefinder before executing passive contrast detection. The rangefinder quickly provides an initial focus setting that brings the system close to the optimal focus point, reducing the search space and iterations required for contrast detection. This preliminary action significantly accelerates the overall focusing process while maintaining precision.
3Measurement precision
If hybrid autofocus systems combining active and passive techniques are used, then both focusing speed and precision are improved, but device complexity increases
Solution Approach 1:
The patent makes the image sensor serve dual purposes: capturing images for data reading and performing passive autofocus through contrast detection. By utilizing the existing image sensor and image processor for both primary imaging and autofocus functions, the system avoids adding dedicated passive autofocus hardware, thereby limiting the increase in device complexity while still achieving improved precision and speed.
4Measurement precision
If phase detection technology is used for passive autofocus, then focus precision is improved, but manufacturing cost increases due to specialized sensors
Solution Approach 1:
The system uses the standard image sensor to capture images, then employs the image processor to perform contrast detection autofocus by analyzing the captured image data. The system serves its own autofocus needs using its existing imaging components, eliminating the requirement for expensive specialized phase-detection sensors and reducing manufacturing costs while maintaining focus precision.
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 achieves rapid and accurate focus in complex environments with multiple items at varying distances, minimizing time to focus and improving data reading efficiency by leveraging both active and passive autofocus methods.
Implementation Method 1
Active autofocus systems measure distance in a variety of ways, such as by using rangefinders to emit ultrasonic sound waves and measuring the delay in their reflection, or by using infrared light to triangulate the distance to the object/item
Implementation Method 2
Contrast detection autofocus may be achieved by measuring contrast through the lens within a sensor field, and comparing the intensity difference between adjacent pixels to correct image focus
Data Source
AI summary
The present disclosure relates to data readers including an improved imaging system that optimizes active and passive autofocus techniques for improving data reading functions. In an example, the data reader initially uses active autofocus techniques to focus a lens system based on a measurement reading by a rangefinder and acquire an image of an item in the field-of-view of the data reader. The data reader includes a decoding engine operable to decode an optical code of the item using the acquired image. If the decoding engine is unable to decode the optical code using the active autofocus technique, the data reader alternates to a passive autofocus technique to alter the focus settings of the lens system and reattempt the decoding process.