Camera Module Phase Extraction Segmentation for ToF Power Efficiency
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Solution Overview
Problem
The time-of-flight (ToF) method for acquiring distance information is limited by high processing speed and power consumption, and accuracy decreases with increasing distance.
Innovation Solution
A camera module with a light output unit, sensor, and control unit that includes a non-extraction area where the phase difference is not extracted, and an extraction area where it is, allowing for efficient timing control and improved accuracy by synthesizing optical signals with reference signals of different phases, and using a filter with different wavelength bands to enhance distance measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the entire sensor area extracts phase difference for distance measurement, then distance information coverage is maximized, but power consumption increases significantly
Solution Approach 1:
The sensor is divided into multiple pixel groups, where only a subset of pixel groups (first pixel groups) perform full phase difference extraction for distance measurement, while other pixel groups (second pixel groups) perform reduced extraction. This segmentation allows the system to maintain distance measurement capability for critical areas while reducing overall power consumption through selective processing.
Solution Approach 2:
Different pixel groups are assigned different processing qualities based on their functional requirements. First pixel groups located in specific regions perform complete phase difference extraction to ensure accurate distance measurement, while second pixel groups perform simplified extraction. This local differentiation optimizes the balance between measurement accuracy and power consumption.
2Measurement precision
If timing control is applied to all pixel groups, then distance measurement accuracy is improved, but processing complexity and power consumption increase
Solution Approach 1:
Pixel groups are segmented into two categories with different timing control applications. First pixel groups receive full timing control for accurate distance measurement, while second pixel groups have timing control stopped or reduced. This segmentation reduces overall processing complexity while maintaining accuracy where needed.
Solution Approach 2:
Instead of applying timing control to all pixel groups (excessive action), the system applies timing control only to the necessary first pixel groups (partial action). This partial application reduces processing complexity and power consumption while maintaining sufficient measurement accuracy for the critical measurement areas.
3Quantity of substance
If all pixels process reflected optical signals, then complete image data is obtained, but power consumption and processing load increase
Solution Approach 1:
The sensor pixels are segmented into first and second pixel groups with different processing functions. First pixel groups process reflected optical signals for distance measurement, while second pixel groups either process signals differently or not at all. This segmentation maintains essential image data completeness while significantly reducing power consumption and processing load.
Solution Approach 2:
The system extracts and processes only the necessary portion of image data through selective pixel group activation. By taking out the essential distance measurement function from all pixels and concentrating it in first pixel groups, the system reduces overall processing load and power consumption while maintaining the critical measurement capability.
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 camera module achieves efficient power consumption and improved accuracy in generating 3D content with distance information, even at increased distances, by optimizing the extraction and processing of phase differences and wavelength bands.
Implementation Method 1
a control unit configured to acquire distance information of the object using a phase difference of the received optical signal
Implementation Method 2
The sensor may synthesize the received optical signal with a plurality of reference signals having different phases to generate a plurality of electrical signals
Implementation Method 3
The camera module may further include a filter disposed between the object and the sensor, wherein the filter includes a first filter area of which a pass band is the first wavelength band, and a second filter area of which a pass band is a second wavelength band
Data Source
AI summary
According to an embodiment of the present invention, disclosed is a camera module comprising: a light output unit for outputting an optical signal to an object; a sensor for receiving an optical signal reflected from the object; and a control unit for acquiring distance information about the object by using the phase difference of the received optical signal, wherein the sensor includes a non-extraction area from which the phase different is not extracted and an extraction area from which the phase difference is extracted and the control unit stops timing control for the received optical signal in the non-extraction area.