Time-of-Flight Ranging With Dual Exposure to Prevent Saturation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing distance measuring devices have limited measurable distance ranges and dynamic ranges, leading to saturation issues in distance measurement.
Innovation Solution
A distance measuring device and method that utilize a light emitting unit, a light receiving unit, and a control unit to perform first and second imaging with different exposure times, duty ratios, or emission intensities to calculate distances, extending the measurable range and improving dynamic range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single exposure time is used in distance measurement, then the measurement process is simple, but the measurable distance range is limited and saturation occurs
Solution Approach 1:
The measurement process is segmented into multiple imaging operations with different exposure times (first imaging with first exposure time, second imaging with second exposure time). This allows the system to measure different distance ranges using appropriate exposure times, extending the overall measurable distance range while avoiding saturation in any single measurement
Solution Approach 2:
The exposure time is made dynamic and adjustable based on measurement needs. The control unit selectively applies different exposure times (first exposure time for closer objects, second exposure time for farther objects) to optimize the measurement for each specific distance range, preventing saturation while maximizing measurable range
2Device complexity
If a single duty ratio is used in distance measurement, then the system operation is simple, but the dynamic range is limited
Solution Approach 1:
The measurement process is divided into multiple imaging operations with different duty ratios. The first imaging uses a first duty ratio while the second imaging uses a second duty ratio, allowing the system to adapt to different signal strength conditions and extend the measurable dynamic range without requiring complex real-time adjustment mechanisms
Solution Approach 2:
The light emitting unit operates with periodic modulation at different duty ratios during different imaging operations. This periodic action with varying duty ratios enables the system to capture signals across a wider dynamic range by adapting the emission pattern to the distance and reflectivity characteristics of different objects
3Device complexity
If a single emission intensity is used in distance measurement, then the control mechanism is simple, but saturation occurs in distance measurement
Solution Approach 1:
The measurement process is segmented into multiple imaging operations with different emission intensities. The first imaging uses a first emission intensity while the second imaging uses a second emission intensity, allowing the system to avoid saturation by selecting appropriate intensity levels for different distance ranges and object reflectivities
Solution Approach 2:
The emission intensity parameter is changed between different imaging operations. By varying the emission intensity (first emission intensity for one imaging, second emission intensity for another imaging), the system adapts to different measurement conditions and avoids saturation while maintaining measurement accuracy across various distance ranges
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 solution enables extended measurable distance range and improved dynamic range in distance measurement, overcoming saturation limitations.
Implementation Method 1
a light receiving unit that receives reflected light of the irradiation light reflected by an object
Implementation Method 2
a light receiving unit that receives reflected light of the irradiation light reflected by an object
Data Source
AI summary
Provided is a distance measuring device including a light emitting unit that emits irradiation light, a light receiving unit that receives reflected light of the irradiation light reflected by an object, a calculation unit that calculates a distance to the object, on the basis of the time from emission of the irradiation light to reception of the reflected light, and a control unit that controls the light emitting unit and the light receiving unit. The control unit controls first imaging that causes the light receiving unit to perform exposure for a first exposure time, and second imaging that causes the light receiving unit to perform exposure for a second exposure time. The calculation unit calculates the distance, using a signal obtained by the first imaging and a signal obtained by the second imaging. The present technology can be applied to a distance measuring device that measures a distance to a predetermined object, for example.