Optical Scanner Shading Unit for Stray Light Interference
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Solution Overview
Problem
Conventional optical scanner apparatuses face issues with signal variation due to stray light or ambient light irradiation on sensors and interconnects, leading to inaccurate control of mirror oscillation angles.
Innovation Solution
Incorporating a shading unit within the optical scanner apparatus to shield sensors and interconnects from stray light and ambient light, using a package cover with strategically designed open portions to prevent light exposure, and optionally employing a heat buffer layer and reflection film to further reduce signal variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sensors and interconnects are provided in the optical scanner unit to detect and control mirror oscillation, then measurement precision and control capability are improved, but the sensors and interconnects become vulnerable to stray light and ambient light causing output signal variation
Solution Approach 1:
A shading member is introduced as an intermediary element between the harmful light and the sensor/interconnect. This shading member selectively blocks stray light and ambient light from reaching the sensor and interconnect, while allowing the necessary incident light to reach the mirror for oscillation detection. The shading member acts as a mediator that protects the sensitive components without interfering with the functional light paths.
Solution Approach 2:
The optical scanner unit is segmented into distinct functional zones: a light-receiving region for incident light to reach the mirror, and a protected region where the sensor and interconnect are shielded from stray light. The shading member creates spatial segmentation by defining which areas are exposed to light and which are protected, allowing simultaneous operation of light detection and signal measurement without mutual interference.
2Productivity
If the optical scanner unit is designed to allow incident light to reach the mirror for scanning, then the scanning function is maintained, but stray light from the incident light path can irradiate the sensor and interconnect causing signal variation
Solution Approach 1:
Different regions of the optical scanner unit are assigned different light transmission properties. The shading member is positioned to provide selective shading: it blocks stray light from reaching the sensor and interconnect while allowing incident light to pass through to the mirror. This local differentiation of light exposure quality enables the coexistence of effective scanning function and protected signal detection.
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 effectively reduces output signal variations in piezo-electric sensors, enabling accurate detection of mirror oscillation angles and precise control of mirror movement.
Implementation Method 1
a sensor (191) that detects an oscillation angle of the mirror
Implementation Method 2
a shading unit (400, 410) that shades the sensor and the interconnect from stray light of the incident light and ambient light
Data Source
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AI summary
An optical scanner apparatus that oscillates a mirror to scan incident light, includes an optical scanner unit that includes a sensor that detects an oscillation angle of the mirror, and an interconnect connected to the sensor; and a shading unit that shades the sensor and the interconnect from stray light of the incident light and ambient light.