ToF Camera Module Thermal Coupling for Cold-Start Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Camera modules with Time of Flight (ToF) sensors experience malfunction and instability at low temperatures, leading to impaired functionality and image disturbances.
Innovation Solution
Incorporating a heat conduction member, such as a lens holder made of thermally conductive materials, to retain the temperature of the ToF sensor and computer, and using a control system to adjust the heat generation of the light source based on temperature sensors to maintain optimal operating conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the camera module operates in a low temperature environment, then the device can function in cold conditions, but the ToF sensor malfunction and image quality deteriorates
Solution Approach 1:
The patent converts the harmful cold environment into a beneficial heating source by using the light source (VCSEL) to generate heat that warms the ToF sensor. The light source operates in pulse mode where the off-period allows heat accumulation in the lens holder, which then conducts heat to the ToF sensor during the next pulse cycle, transforming the cold environment problem into a self-heating solution.
Solution Approach 2:
The patent changes the operational parameters of the light source from continuous emission to pulsed emission with specific duty cycles. By adjusting the pulse width and frequency, the system controls the heat generation timing and amount, allowing the lens holder to accumulate heat during off-periods and transfer it to the ToF sensor during operation periods, thus maintaining sensor temperature in cold environments.
2Reliability
If a heater is added to maintain ToF sensor temperature, then the sensor can operate reliably at low temperatures, but the device complexity increases
Solution Approach 1:
The patent makes the light source serve dual functions: emitting light for ToF measurement and generating heat for sensor temperature maintenance. The lens holder also serves dual purposes as both the mechanical mounting structure for optical components and as a heat conduction path from the light source to the ToF sensor. This eliminates the need for separate heater components.
Solution Approach 2:
The system uses its own operational components (light source and lens holder) to maintain the temperature of the ToF sensor without requiring external heating devices. The light source's inherent heat generation during normal operation is utilized to warm the sensor, making the system self-sufficient for temperature control in cold environments.
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
Enhances detection accuracy and reliability of the ToF sensor by maintaining optimal temperature ranges, expanding the operational temperature range, and preventing image malfunctions due to temperature fluctuations.
Implementation Method 1
a heat conduction member that conducts the heat of the light source to the ToF sensor
Implementation Method 2
a light source configured to emit light and generate heat
Data Source
AI summary
A camera module includes, for example, a light source, a ToF sensor configured to detect reflected light from a subject that receives light from the light source, and a heat conduction member that conducts heat of the light source to the ToF sensor.