Optical Sensor Angle Limiting Filter Side Surface Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical sensors with angle limiting filters face a reduction in spectroscopic characteristics when light from the side surface passes through, leading to compromised performance.
Innovation Solution
An optical sensor design that includes a light receiving element, an optical filter transmitting specific wavelengths, and an angle limiting filter with a controlled incident angle, where the overlap distance between the optical filter and the angle limiting filter is set to satisfy tan−1(OV/RTP) > θA, allowing for precise adjustment of the aperture width and height to limit incident angles effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a spectroscopic filter is formed on the angle limiting filter, then the spectroscopic characteristics are improved, but light incident from the side surface passes through the angle limiting filter and reduces spectroscopic characteristics
Solution Approach 1:
The patent introduces a new spatial dimension by forming the optical filter on the side surface of the angle limiting filter rather than on its top surface. This side-surface configuration creates an additional optical path that blocks oblique incident light from reaching the light receiving element, while still allowing the angle limiting filter to function. The optical filter is positioned at a location where it can intercept side-incident light without interfering with the normal incident light path.
Solution Approach 2:
The optical filter acts as an intermediary element that specifically targets and blocks side-incident light before it can reach the light receiving element. By positioning the optical filter on the side surface of the angle limiting filter, it serves as a mediator that selectively removes harmful oblique light components while allowing the angle limiting filter and spectroscopic filter to maintain their intended functions for normal incident light.
2Measurement precision
If the overlap distance OV is increased to block side surface light, then spectroscopic characteristics are maintained, but the device structure becomes more complex
Solution Approach 1:
The patent merges multiple functions into a single integrated structure where the optical filter is formed directly on the side surface of the angle limiting filter. This combination eliminates the need for separate blocking structures and reduces overall device complexity. The optical filter and angle limiting filter work together as a unified optical element that simultaneously performs wavelength filtering and incident angle control.
Solution Approach 2:
The patent optimizes the overlap distance parameter OV to satisfy the condition tan−1(OV/RTP)>θA, where RTP is the height from the upper surface of the angle limiting filter to the upper surface of the optical filter, and θA is the limitation angle. By carefully controlling this geometric parameter, the patent achieves effective blocking of side-incident light while maintaining a compact and simple device structure.
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 effectively suppresses the reduction of spectroscopic characteristics by ensuring that only light within the specified angle range reaches the light receiving element, maintaining high sensor sensitivity and accuracy.
Implementation Method 1
an optical filter that transmits a light having a specific wavelength of incident lights with respect to a light receiving region of the light receiving element
Implementation Method 2
an angle limiting filter that limits an incident angle of the incident light transmitted through the optical filter
Implementation Method 3
light receiving element
Data Source
AI summary
To provide an optical sensor, an electronic apparatus, etc. that suppress reduction of spectroscopic characteristics. The optical sensor includes a light receiving element, an optical filter 140 that transmits a light having a specific wavelength of incident lights with respect to a light receiving region of the light receiving element, and an angle limiting filter 120 that limits an incident angle of the incident light transmitted through the optical filter 140.