Stacked Visible and NIR Sensor Layout for Color Purity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing imaging devices face challenges in improving sensor performance without increasing sensor size or number, particularly in low-illumination environments, and in preventing damage to visible light sensors from near-infrared light.
Innovation Solution
A sensor configuration that includes a visible light sensor and a near-infrared light sensor stacked in a Z-direction, with an optical filter selectively transmitting visible and near-infrared light while blocking adjacent near-infrared wavelengths, enhancing light purity and reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sensor is designed to detect both visible light and near-infrared light, then sensitivity in low-illumination environments is improved, but the sensor size increases
Solution Approach 1:
The patent transitions from horizontal arrangement to vertical stacking, placing the visible light sensor and near-infrared sensor in different layers along the Z-axis. This dimensional change allows both sensors to coexist without increasing the sensor's footprint area, while maintaining the ability to detect both visible and near-infrared light for improved low-illumination sensitivity.
Solution Approach 2:
The sensor is divided into distinct functional layers: a visible light sensor layer and a near-infrared sensor layer. Each layer is optimized for its specific wavelength range, with the visible light sensor detecting wavelengths of 400-700nm and the near-infrared sensor detecting wavelengths of 700-1000nm. This segmentation allows independent optimization of each sensor type without compromise.
2Reliability
If near-infrared light is allowed to reach the visible light sensor, then near-infrared detection capability is improved, but color image quality deteriorates due to interference
Solution Approach 1:
The patent extracts and separates the near-infrared detection function into a dedicated near-infrared sensor layer, isolating it from the visible light sensor. This extraction prevents near-infrared light from interfering with the visible light sensor's color detection, while still enabling near-infrared detection capability through the separate sensor layer.
Solution Approach 2:
An optical filter layer is introduced as an intermediary between the visible light sensor and the near-infrared sensor. This filter selectively transmits near-infrared wavelengths to the near-infrared sensor while blocking them from reaching the visible light sensor, thereby preventing color interference while maintaining near-infrared detection capability.
3Manufacturing precision
If multiple sensors are stacked in the Z-direction, then light purity and color image quality are improved, but device complexity increases
Solution Approach 1:
The stacked sensor structure serves multiple functions simultaneously: the visible light sensor captures color information for normal imaging, the near-infrared sensor captures near-infrared light for low-illumination enhancement and special imaging modes, and the optical filter manages wavelength separation. This multi-functionality justifies the increased structural complexity by delivering superior light purity and color image quality across different imaging scenarios.
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 configuration improves sensor performance by maintaining size efficiency, increasing visible light purity, and achieving better color image quality by effectively blocking near-infrared light from affecting the visible light sensor.
Implementation Method 1
an optical filter selectively transmitting visible and near-infrared light while blocking adjacent near-infrared wavelengths
Implementation Method 2
a near infra-red absorption layer between the pair of electrodes. The near infra-red absorption layer may include an organic light-absorbing material configured to absorb light in the near infra-red wavelength spectrum
Implementation Method 3
The photoelectric device may include a pair of electrodes facing each other, and a visible absorption layer between the pair of electrodes. The visible absorption layer may be configured to absorb light in one wavelength spectrum of a blue wavelength spectrum, a green wavelength spectrum, and a red wavelength spectrum
Implementation Method 4
The blue sensor, the green sensor, and the red sensor may be integrated in a semiconductor substrate. Two sensors of the blue sensor, the green sensor and the red sensor may be photodiodes integrated in a semiconductor substrate
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A sensor includes a visible light sensor configured to sense light in a visible wavelength spectrum, a near infra-red light sensor on the visible light sensor and configured to sense light in a near infra-red wavelength spectrum, and an optical filter on the near infra-red light sensor and configured to selectively transmit the light in the visible wavelength spectrum and the light in the near infra-red wavelength spectrum, and an electronic device.