Distance Measuring Device with APD and Dynamic Range Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional distance measuring devices struggle to accurately measure distances due to variations in background light intensity, such as sunlight, which can lead to incorrect detection and measurement of reflected light, especially when the background light intensity differs from the reflected light intensity.
Innovation Solution
A distance measuring method and device that measure the illuminance of background light, set a distance measuring range based on this illuminance, and adjust the image capturing conditions and emission conditions for an image capturer with avalanche photo diodes (APDs) to control the measurement process, ensuring accurate distance measurement by managing the exposure time and emission conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If background light correction is performed using conventional techniques, then light detection sensitivity is improved, but measurement precision deteriorates when background light intensity varies significantly
Solution Approach 1:
The patent applies dynamics by making the image capturing conditions (exposure time, gain) variable based on the measured background light illuminance. Instead of using fixed correction parameters, the system dynamically adjusts capturing conditions to match the current lighting environment, ensuring reliable detection across varying light intensities.
Solution Approach 2:
The patent changes the parameters of the image capturing conditions (exposure time, gain settings) based on the background light illuminance level. By adjusting these parameters according to the measured illuminance, the system maintains optimal detection performance whether the background light is strong or weak.
2Measurement precision
If the image capturer operates continuously without adjustment, then detection speed is maintained, but measurement precision deteriorates due to varying background light conditions
Solution Approach 1:
The patent performs preliminary measurement of the background light illuminance before capturing reflected light for distance measurement. Based on this preliminary information, the system pre-adjusts the image capturing conditions (exposure time, gain) to optimal values, ensuring that when reflected light detection is performed, the capturing conditions are already optimized for the current lighting environment.
Solution Approach 2:
The system implements feedback by measuring the background light illuminance and using this information to adjust the image capturing conditions. This closed-loop approach ensures that the capturing conditions always match the current lighting environment, maintaining both precision and efficiency.
3Adaptability or versatility
If the distance measuring range is extended to cover all possible distances, then adaptability is improved, but measurement precision deteriorates in specific conditions due to background light interference
Solution Approach 1:
The patent makes the distance measuring range dynamic by adjusting the image capturing conditions based on background light illuminance. When background light is strong, the system reduces the effective measuring range to distances where reflected light can still be detected above the background noise. When background light is weak, the system can extend the measuring range further, optimizing the balance between adaptability and precision for each lighting condition.
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 allows for appropriate distance measurement by setting a suitable range based on background light conditions, reducing errors and enabling accurate detection of distances even under varying light conditions, thereby enhancing the accuracy and reliability of distance measurements.
Implementation Method 1
an avalanche photo diode (APD) which is a photodiode that uses avalanche breakdown to multiply charge generated by photoelectric conversion of light incident on a photoelectric conversion layer
Implementation Method 2
an avalanche photo diode (APD) which is a photodiode that uses avalanche breakdown to multiply charge generated by photoelectric conversion of light incident on a photoelectric conversion layer (that is, avalanche multiplication)
Implementation Method 3
an emission condition in which light is emitted from a light source
Data Source
AI summary
A distance measuring method according to the present disclosure includes: measuring, in an environment where background light is applied to an object, the illuminance of the background light; setting a distance measuring range based on the illuminance of the background light; setting, based on the distance measuring range set, an image capturing condition for an image capturer including a plurality of pixels each including an avalanche photo diode (APD) and an emission condition in which light is emitted from a light source; and measuring a distance to the object by controlling the image capturer and the light source based on the image capturing condition and the emission condition that are set.