Distance Measurement Correction Using Transient Thermal Data
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing distance measurement techniques for digital cameras fail to accurately correct distance shifts caused by temperature changes, especially when the heat transmitted to the lens has not reached a stationary state, leading to measurement errors.
Innovation Solution
A distance measurement apparatus that includes processors and memory to calculate and correct distance information using temperature information obtained at different times, allowing for accurate object distance calculation even during temperature changes by estimating the temperature of the optical system at the time of image capturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If temperature correction is performed using a temperature table provided in the lens barrel, then distance measurement accuracy is improved under stationary temperature conditions, but measurement accuracy deteriorates when the heat transmitted to the lens has not turned into a stationary state
Solution Approach 1:
The system performs preliminary temperature measurements at multiple time points before the actual image capture. By measuring temperature at predetermined intervals and storing these temporal temperature data, the system prepares in advance to account for transient temperature states, enabling accurate distance correction even when temperature has not reached a stationary state
Solution Approach 2:
The system continuously monitors temperature changes over time and uses this feedback to dynamically adjust the distance correction. By comparing temperature measurements taken at different times and determining the temperature change rate, the system adapts the correction amount in real-time, ensuring accurate distance measurement during transient thermal conditions
2Measurement precision
If focus driving is performed to correct defocus shift caused by temperature change, then focusing accuracy is improved, but distance information correction capability is lost
Solution Approach 1:
The system replaces the mechanical focus driving approach with a computational method. Instead of physically moving the focus lens to correct defocus, the system calculates the temperature-induced defocus amount based on temperature measurements and correction tables, then directly adjusts the distance information through software processing, preserving distance measurement capability while achieving focusing correction
Solution Approach 2:
The system introduces temperature measurement data and correction tables as intermediaries between the temperature change and the distance correction. By using the temperature value as a mediator to look up correction amounts in a pre-established table, the system indirectly corrects the distance information without needing to physically adjust the optical system, thus maintaining both focusing accuracy and distance information integrity
Data Source
AI summary
A distance measurement apparatus includes one or more processors, and a memory storing instructions which, when executed by the one or more processors, cause the distance measurement apparatus to function as a calculation unit configured to calculate distance information corresponding to an image captured by an imaging apparatus using an image sensor that captures an object image focused on the image sensor via an optical system, a temperature information obtaining unit configured to obtain temperature information of the imaging apparatus at different times, and a distance correction unit configured to correct the distance information, wherein the distance correction unit corrects the distance information based on the temperature information at a time at which a first image capturing is performed and the temperature information at a time before the first image capturing is performed.