The previous two articles introduced video measuring machines and digital projectors respectively, including their basic functions, principles, practical applications in the eyewear industry, and their respective advantages. No one is perfect, and the moon waxes and wanes; the same goes for measuring instruments. Only by complementing each other's strengths can they safeguard eyewear quality.
When measuring data, a digital projector can only rely on the naked eye to observe whether an edge aligns with a horizontal line, with no machine-assisted indication, so certain errors may occur; moreover, it cannot measure the concentricity error of concentric circles at all (this is not speculation: flip the same clamp opening, project the large circle and the small circle separately, then place them on a CAD drawing with proportional frames for comparison, and the resulting circle sizes are consistent), so other tools are needed for measurement. A video measuring machine, on the other hand, has machine assistance, using horizontal lines to indicate whether alignment with the horizontal line is achieved, and then the machine precisely reads out the numbers, giving it a clear advantage in data accuracy. Furthermore, it uses imaging rather than projection, so it can measure the data of the large circle and the small circle within concentric circles separately, thereby determining the positions of their centers respectively and then measuring concentricity.
The above is roughly the extent to which the two machines can complement each other. The process is roughly as follows: first use a digital projector to inspect the contour and check for burrs and notches; after confirming there are no issues, use a video measuring machine to measure data, determine whether it can pass AQL sampling inspection, or judge whether the data of a trial-produced product is compliant, in order to decide whether to proceed to mass production.
Of course, the detailed process is certainly more complex; this article focuses only on introducing the complementarity of video measuring machines and digital projectors, and other processes are omitted. If you need a more detailed understanding, or if you find errors in the description or have something to add, you are welcome to contact us at any time for discussion.
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