Camera Module Optical Path Shifting for High-Resolution Depth
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Solution Overview
Problem
The Time of Flight (TOF) method for acquiring depth information faces challenges in achieving high resolution without increasing the volume and manufacturing cost of camera modules, as current methods result in low information per frame.
Innovation Solution
A camera module design that includes a lighting unit, lens unit, image sensor unit, tilting unit, and image control unit, which shifts the optical path for each image frame in subpixels and rearranges pixel values to generate high-resolution depth information using phase differences between incident and reflected light signals, allowing for increased resolution without increasing pixel count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of pixels in an image sensor is increased to increase resolution, then the resolution is improved, but the volume and manufacturing cost of the camera module are significantly increased
Solution Approach 1:
The patent applies optical path shifting in the spatial dimension by using a tilting unit to shift the optical path of incident or reflected light in units of subpixels. This dimensional approach allows the system to capture multiple subpixel-shifted images using the same pixel array, effectively increasing resolution without adding more pixels or increasing module volume.
Solution Approach 2:
The tilting unit dynamically shifts the optical path between different image frames, creating temporal variation in the optical configuration. This dynamic adjustment allows the same hardware to capture multiple perspectives over time, achieving high resolution depth information without requiring a larger static sensor array.
2Measurement precision
If the number of pixels in an image sensor is increased to increase resolution, then the resolution is improved, but the manufacturing cost is significantly increased
Solution Approach 1:
Instead of increasing pixel count in the same dimension, the patent introduces optical path shifting in the spatial dimension. The tilting unit shifts light paths by subpixel amounts across multiple frames, allowing high-resolution depth extraction from a standard-resolution sensor, thereby avoiding the cost increase associated with higher-pixel-count sensors.
Solution Approach 2:
The system captures multiple copies of the same scene from slightly different optical perspectives by shifting the optical path in units of subpixels across different frames. These multiple subpixel-shifted images are then processed to reconstruct high-resolution depth information, effectively creating virtual copies of the imaging process without additional hardware cost.
3Speed
If the current TOF method is used to acquire depth information, then real-time distance information is provided rapidly, but the amount of information obtained from each frame (resolution) is very small
Solution Approach 1:
The tilting unit dynamically shifts the optical path between frames while the TOF method continues to operate in real-time. This dynamic optical path shifting allows the system to maintain rapid real-time measurement capability while accumulating multiple subpixel-shifted frames that are later processed to achieve high resolution, thus resolving the contradiction between speed and precision.
Solution Approach 2:
The system performs preliminary capture of multiple subpixel-shifted frames using the rapid TOF method before processing them to extract high-resolution depth information. This preliminary action allows the fast real-time capability to be preserved during data collection, while the resolution enhancement is achieved in a subsequent processing stage.
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
Enables high-resolution depth information acquisition with minimal additional computation, effectively enhancing the resolution of depth maps without increasing the number of image sensor pixels or module size.
Implementation Method 1
an image sensor unit configured to generate electric signals from the reflected light signal concentrated by the lens unit
Implementation Method 2
a tilting unit configured to shift an optical path of at least one of the incident light signal and the reflected light signal for each image frame in units of subpixels of the image sensor unit
Implementation Method 3
an image control unit configured to extract depth information of the object using a phase difference between the incident light signal and the reflected light signal
Data Source
AI summary
A camera module including a lighting unit configured to output an incident light signal to be emitted to an object, a lens unit configured to concentrate a reflected light signal reflected from the object, an image sensor unit configured to generate electric signals from the reflected light signal concentrated by the lens unit, a tilting unit configured to shift an optical path of at least one of the incident light signal and the reflected light signal for each image frame in units of subpixels of the image sensor unit, and an image control unit configured to extract depth information of the object using a phase difference between the incident light signal and the reflected light signal. The image control unit includes an image controller configured to extract the depth information having a higher resolution than a plurality of subframes generated using the electric signals on the basis of the subframes.