Variable Focus Line Sensor Camera for Long Substrate Detection
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Solution Overview
Problem
Existing component mounting apparatuses face challenges in detecting components on pickup nozzles with high precision when handling long substrates, due to the fixed focus optical system in line sensor cameras, leading to low focusing levels and inaccurate detection.
Innovation Solution
A component mounting apparatus with a variably controlled optical system in the line sensor camera, combined with a transfer pathway calculation and imaging control unit, adjusts the focusing point to match the transfer pathway of the mounting head, ensuring accurate detection of components on the nozzles even with long substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed focus optical system is used in the line sensor camera, then the device complexity is reduced, but the measurement precision deteriorates when handling long substrates
Solution Approach 1:
The patent applies the dynamics principle by transitioning from a fixed focus optical system to a variable focus optical system. The focusing point of the optical system can be dynamically adjusted to match different transfer pathway positions, enabling clear imaging at various distances from the line sensor camera. This resolves the contradiction by making the optical system adaptable to different working conditions (long vs. normal substrates) while maintaining measurement precision.
Solution Approach 2:
The patent implements parameter changes by varying the focusing point parameter of the optical system based on the substrate length and transfer pathway position. The control unit adjusts the focal distance parameter to optimize image quality at different detection positions, thereby maintaining high measurement precision across different substrate types without increasing overall device complexity.
2Adaptability or versatility
If the detection spacing between light projector and line sensor camera is increased for long substrates, then the adaptability is improved, but the measurement precision deteriorates due to larger imaging focal point range
Solution Approach 1:
The patent resolves this contradiction by making the focusing point dynamic rather than fixed. The optical system can adapt its focal distance to compensate for the larger imaging focal point range caused by increased detection spacing. This allows the system to maintain measurement precision while accommodating long substrates with larger detection spacing requirements.
Solution Approach 2:
The control unit uses feedback from the transfer pathway position information to adjust the focusing point of the optical system. By receiving position data and corresponding this information to the appropriate focal distance, the system maintains precise component detection despite the larger imaging focal point range necessitated by long substrate handling.
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-precision detection of components on the pickup nozzles, preventing 'brought-back' components and ensuring smooth operation by adjusting the focusing point to match the transfer pathway, enhancing detection accuracy for long substrates.
Implementation Method 1
an optical system whose focusing point is variably set on the line sensor camera
Implementation Method 2
a light projector and a line sensor camera... projecting a belt-shaped inspection beam
Data Source
AI summary
A transfer pathway of a mounting head 10 in a component-mounting round during which the mounting head 10 moves back and forth between a component feeding unit 4 and a substrate conveyance mechanism 2 is derived by a transfer pathway calculation unit 25 for each component-mounting round from mounting program data 21a. A focusing processing unit 24 controls an optical system focusing mechanism 18, thereby matching a focusing point of a line sensor camera 14 achieved during imaging operation to the transfer pathway of the mounting head 10 based on data pertaining to the derived transfer pathway. Further, an optical system zooming mechanism 17 adjusts an imaging range according to the focusing point. Accordingly, even when a long substrate 3 is taken as an object, it is possible to detect with high precision whether or not a component exists on the pickup nozzle 11 of the mounting head 10.