Surface quality inspection of a 5 mm lens on micron scale.


The production of high volume high quality lenses are done by so called injection moulding process.
The quality of the lens surface is as good as the mould itself or less.
To create a high accurate injection mould special tooling is required and used to create the special lens shape in the mould.
Though it is possible that the mould and the resulting lenses have some damages, scratches or imperfections.
It is difficult to visualize these defects on micron scale using common optics and common illuminations.

Therefore J.A.I.M.S. developed:

  • special optics to create a good as possible image
  • special illumination to visualize the defects and imperfections on micron scale of this curved lens surface.
  • .
    The image is an compilation of 4 images and results in an image of 3600x3600 pixels. This image shows the tooling grooves and the defects in detail. To create these images the lenses instead of the mould are uses. But it is also possible to inspect the surface of the mould itself.
    Lens_Quality scratch NOT visible Lens_Quality scratch visible Lens_Quality Marker visible Lens_Quality Marker visible Subimage Lens_Quality scratch visible





    The first image, created with a regular illumination, contains a bright marker at the right side. The scratch under this marker is NOT visible in this image.
    The second image shows the result of the special designed illumination.
    The marker is visible AND the scratch is also clearly visible.
    And of course the tooling groves are visible. These tooling groves does not influence the quality of the lens.
    The subimages shows the marker using a regular illumination and the special designed illumination.
    The scratch is visible in the last subimage.

    The next lens is damaged at the top, the damage is a so called " water line ".
    Lens_Quality water line NOT visible Lens_Quality water line visible Lens_Quality water line visible Here the first image is created using a regular illumination. The damage, so called " water line " on the top of the lens is NOT visible.
    The second image is the result of the JAIMS special illumination. The "water line" is clearly visible.
    The third image is a subimage of this "water line".





    The next example is a lens (mould) with dust on the top and a damage "water drops" at the bottom of the image.

    Lens_Quality water drops NOT visible Lens_Quality water drops visible Lens_Quality water drops visible The first image is created using a regular illumination, the dust on top of the lens is visible BUT the "water drops" on the bottom of the lens is NOT visible!
    The second image is the result of the JAIMS special illumination. The "water drops" are clearly visible. The dust is almost not visible. Inspection of the lens using the JAIMS special illumination is not influenced by dust.
    The third image is a subimage, containing the "water drops". For enlarged images click on the image itself.

    To be sure the camera optics are focussed on the surface, the tooling grooves have to be visible.