CCD Sensor Inverted Signal Processing for High Light Saturation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical code scanners face challenges in maintaining a wide dynamic range of usable illumination conditions, as they often become saturated in high light environments, leading to difficulties in distinguishing between code elements and requiring costly and complex compensation mechanisms like dynamic apertures or electronically adjustable attenuators.
Innovation Solution
The system employs a CCD sensor that exhibits two output modes: standard and inverted, where the sensor outputs an inverted signal in high light conditions, allowing for signal re-inversion in the signal processing chain to maintain decodability, thereby extending the dynamic range without moving parts or additional complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard imaging mode is used in high light conditions, then the sensor becomes saturated and cannot distinguish code elements, but if dynamic apertures or electronically adjustable attenuators are added to compensate, then cost and complexity increase
Solution Approach 1:
The patent applies inversion by utilizing the sensor's inverted output mode that naturally occurs under high saturation conditions. Instead of fighting against saturation with complex attenuation mechanisms, the system inverts the image data digitally when saturation is detected, converting the inverted sensor output back into a readable format. This transforms the harmful saturation effect into a usable signal, resolving the contradiction between reliability in high light and system complexity.
Solution Approach 2:
The system changes the parameter of image data processing by switching between standard and inverted output modes based on detected light conditions. The controller monitors sensor output and dynamically adjusts the image processing approach - using standard mode for normal conditions and inverted mode for high saturation conditions. This parameter change allows the system to maintain code reading reliability across varying light conditions without adding complex hardware.
2Adaptability or versatility
If dynamic apertures or electronically adjustable attenuators are added to compensate for light variation, then the dynamic range of usable illumination conditions is improved, but cost and complexity increase
Solution Approach 1:
The patent replaces mechanical aperture systems with electronic/digital image processing. Instead of using moving mechanical parts (dynamic apertures) or complex electronic attenuators to control light input, the system uses a fixed sensor and processes the resulting images digitally - inverting the image data when saturation occurs. This substitution of mechanical/electronic light control with digital signal processing achieves adaptability across illumination conditions while minimizing device complexity.
Solution Approach 2:
The sensor system provides self-service by automatically adapting to different light conditions through its inherent dual output capability. The controller detects saturation conditions and automatically switches to inverted mode processing, allowing the system to serve itself across a wide dynamic range without requiring external complex control mechanisms. This self-adaptation achieves versatility while keeping the system simple.
3Reliability
If electronically adjustable attenuators are used to handle high light conditions, then the sensor saturation problem is solved, but the system requires moving parts and becomes more complex
Solution Approach 1:
The patent replaces mechanical attenuators with digital image inversion processing. Instead of using mechanically adjustable components to reduce light intensity before it reaches the sensor, the system allows the sensor to capture the full light signal and then digitally inverts the resulting inverted output. This substitution eliminates moving parts and maintains system simplicity while ensuring reliable operation in high light conditions.
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 enables optical code scanners to operate effectively across a broad range of light conditions, from low to high intensities, by automatically switching to inverted mode and adjusting exposure times, ensuring successful decoding even in saturated conditions, thus simplifying the device design and reducing costs.
Implementation Method 1
an imaging device or sensor array, such as a CCD (charge coupled device) or CMOS (complementary metal oxide semiconductor) device
Data Source
AI summary
A data reader such as for example an imaging reader with a CCD or CMOS imager or the like, that acquires an image of an item to be read. A certain type of sensor has been found to exhibit different outputs depending upon the light intensity level: (1) standard output whereby the sensor outputs a signal corresponding to the image collected and (2) inverted output whereby the sensor outputs an inverted signal when the light intensity highly saturates the sensor. Taking advantage of this inverted output, systems and methods are then employed by the data reader to convert or otherwise re-invert this inverted signal in order to read an optical code that, for example, might otherwise have been above the upper exposure limit of the sensor/reader and thus not decodable.