Self-aligning Optical Sensor Package Using Lead Frame Reference Features
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Solution Overview
Problem
Optical mice using coherent light sources face challenges in alignment during manufacturing, leading to operational issues and complexity in design, while mechanical mice suffer from inaccuracy and wear due to dirt accumulation.
Innovation Solution
A novel packaging design for optical navigation sensors utilizing a lead frame with reference features to passively align a laser, detector array, and optical component, ensuring precise registration and reducing manufacturing complexities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a coherent light source (laser) is used in optical mice, then pointing accuracy is improved, but alignment precision requirements increase making manufacturing difficult
Solution Approach 1:
The patent applies preliminary action by pre-forming alignment features (such as recesses or protrusions) in the laser housing and corresponding registration features in the lens housing before final assembly. This pre-preparation of alignment structures ensures that when components are assembled, they automatically align to the required precision without requiring complex adjustment procedures during manufacturing, thus maintaining high pointing accuracy while simplifying the manufacturing process
Solution Approach 2:
The patent introduces an intermediary alignment mechanism consisting of registration features that mediate between the laser housing and lens housing. These intermediate features act as a bridge that translates the positioning requirements into simple mechanical registration, allowing components to be assembled with standard tolerances while achieving the precise alignment needed for coherent light source operation
2Ease of manufacture
If standard optical packaging is used, then manufacturing is simpler, but alignment accuracy deteriorates leading to operational issues
Solution Approach 1:
The patent merges the alignment function with the structural housing design by integrating alignment features directly into the laser housing and lens housing components. Rather than using separate alignment mechanisms or adjustment procedures, the housing structures themselves incorporate the alignment functionality, simplifying manufacturing while ensuring reliable alignment and operation
Solution Approach 2:
The patent implements self-service alignment where the component housings contain built-in registration features that automatically guide and secure proper alignment during assembly. The laser housing and lens housing self-align through complementary features such as recesses and protrusions, eliminating the need for external alignment tools or complex adjustment procedures, thus maintaining both manufacturing simplicity and operational reliability
Data Source
AI summary
One embodiment relates to an optical navigation device. The device includes a lead frame having reference features, a laser, a detector array, and an optical component having alignment features. The laser is attached to the lead frame and positioned in reference to the reference features of the lead frame. The detector array is attached to the lead frame and positioned in reference to the reference features of the lead frame. The optical component is coupled to the lead frame so that its alignment features register to the reference features of the lead frame. In this way, the molded optical component is passively aligned to the laser and the detector array. Other embodiments are also disclosed.