Liquid Lens Image Sensor Thermal Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Individual liquid lenses in image sensors exhibit different refractive powers when controlled at a constant temperature, making it challenging to obtain accurate correction information, especially since image processing units generate heat, prolonging the time required for obtaining correction information.
Innovation Solution
An image sensor design that includes a disconnectable lens module with a temperature sensor, heater, and nonvolatile memory to maintain the liquid lens at a constant temperature, allowing for efficient correction of application voltage differences between individual lenses, featuring a refractive power controller that determines and applies the necessary voltage to match target refractive power based on stored property information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the image processing unit is used to obtain correction information, then the liquid lens can be corrected to match target refractive power, but the heat generated by the image processing unit causes the temperature to rise and prolongs the time required to obtain accurate correction information
Solution Approach 1:
The patent extracts the temperature sensing function from the body module and places it in the lens module, allowing independent temperature measurement of the liquid lens without interference from heat generated by the image processing unit in the body module. This enables accurate correction information to be obtained without waiting for thermal saturation.
2Stability of the object's composition
If individual liquid lenses are controlled to have constant temperature, then temperature stability is improved, but the refractive powers still differ due to individual lens properties
Solution Approach 1:
The patent performs preliminary measurement of the actual refractive power of each liquid lens at its stable temperature using the temperature sensor and imaging device. This preliminary action captures the individual characteristics of each lens, allowing the refractive power controller to calculate customized correction voltages that compensate for manufacturing variations and match the target refractive power.
Solution Approach 2:
The patent changes the application voltage parameter based on the measured refractive power of each individual liquid lens. By adjusting the voltage according to the lens's actual properties rather than using a fixed voltage, the system compensates for individual differences and achieves consistent target refractive power across all lenses.
3Device complexity
If the lens module is integrated with the body module, then the system is more compact, but the heat from the body module affects the liquid lens temperature and complicates temperature control
Solution Approach 1:
The patent segments the system into two independent modules: the lens module containing the liquid lens and temperature sensor, and the body module containing the image processing unit. This segmentation allows the liquid lens to be temperature-controlled independently without being affected by heat from the image processing unit, simplifying thermal management while maintaining system integration through electrical connections.
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 design enables accurate and efficient correction of application voltage for individual liquid lenses, reducing the time to achieve focus and allowing for precise property information measurement, thereby improving the production efficiency of image sensors.
Implementation Method 1
A liquid lens is an optical component containing a conductive water solution and a nonconductive oil sealed in a lens holder, with the oil-water interface deforming to change the refractive power in response to a voltage applied
Implementation Method 2
a heater may be used for maintaining the liquid lens at a constant temperature
Data Source
AI summary
An image sensor includes an imaging device, an optical system including a liquid lens, a temperature sensor that detects a temperature of the liquid lens, a heater that heats the liquid lens, a temperature adjuster that controls the heater to adjust the temperature of the liquid lens to a predetermined temperature, a nonvolatile memory storing property information about the liquid lens, a refractive power controller that determines, based on a target refractive power and the property information stored in the nonvolatile memory, an application voltage applicable to the liquid lens adjusted to have the predetermined temperature and applies the application voltage to the liquid lens to control a refractive power of the liquid lens to match the target refractive power, and an image processor. The optical system, the nonvolatile memory, and the temperature sensor are disconnectable from a body module including the refractive power controller and the image processor.