Pixelated Optical Distance Sensor Calibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical distance measuring devices face challenges in accurate calibration and compensation for transit time errors and drifts, and require a compact reference unit for internal calibration.
Innovation Solution
The measuring device employs a receiving device with a large number of pixels, each containing at least one light-sensitive element, such as SPADs, and a reference device with a similar detection surface for internal reference radiation, allowing for improved calibration and reduced propagation time errors through symmetrical array structures and dynamic adjustment of light-sensitive elements based on distance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional single detector or small detector array is used for reference calibration, then the reference unit can be kept simple, but the measurement precision and calibration accuracy deteriorate due to insufficient signal quality and higher propagation time errors
Solution Approach 1:
The detection surface is divided into multiple pixels, each with its own light-sensitive element, allowing independent detection and calibration. This segmentation enables the reference unit to achieve high measurement precision through multiple independent detection points while maintaining manageable complexity through modular pixel structure
Solution Approach 2:
The patent transitions from a single-point reference detection to a multi-point array detection by adding the spatial dimension. The reference device uses a detection surface with multiple pixels arranged in a grid, converting one-dimensional single-detector reference into two-dimensional array reference, thereby improving calibration accuracy without proportionally increasing complexity
2Measurement precision
If a large number of light-sensitive elements are used in each pixel to improve signal-to-noise ratio, then measurement precision improves, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent optimizes the number of light-sensitive elements per pixel as a variable parameter rather than using a fixed large number. Each pixel can have a different number of light-sensitive elements (e.g., 1-9 elements) depending on the required signal strength and noise characteristics for that specific detection region, thereby improving signal-to-noise ratio where needed while simplifying manufacturing where standard detector counts suffice
3Adaptability or versatility
If the detection surface has a large number of pixels with multiple light-sensitive elements each, then the dynamic range and measurement precision improve, but the device complexity and processing requirements increase
Solution Approach 1:
The patent implements dynamic adjustment of the effective detection area by selectively activating different numbers of light-sensitive elements within pixels based on the measurement requirements and signal strength. This dynamic configuration allows the system to adapt the detection sensitivity and range in real-time, expanding dynamic range while managing processing complexity through on-demand activation rather than full-array processing
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 configuration enhances the signal-to-noise ratio, minimizes transit time errors, and optimizes dynamic range, enabling more accurate and robust distance measurements across varying distances.
Implementation Method 1
a receiving device with a detection surface for detecting optical measurement radiation returning from the target object, the detection surface having a large number of pixels, each pixel having at least one light-sensitive element
Implementation Method 2
a transmission device for emitting optical measurement radiation to a target object
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a measurement device (10) for optically measuring a distance to a target object (15), in particular a handheld measurement device. The invention relates to such a measurement device (10) having a transmitting device (12) for transmitting an optical measurement beam (13) to a target object (15); a receiving device (14) having a detection surface (110) for detecting the optical measurement beam (16) returning from the target object (15), wherein the detection surface (110) has a plurality of pixels (111), and each pixel (111) has at least one light-sensitive element (101); and a reference device having a detection surface for detecting a device-internal reference beam. According to the invention, the detection surface (117) of the reference device has a plurality of pixels (127), wherein each pixel (127) has at least one light-sensitive element (107)