Oberflächen mit System

    Lens edge-blackening

    from manual application to an automated process-safe solution


    Why are we doing this? Because we have been dealing with the printing of optical components for many years!

    The aim is to apply a light-absorbing layer outside the optically effective area (circumferential surface/aperture) of optical components by means of edge blackening in order to minimise stray light.

    Benefits & Advantages

    • from a stand-alone system up to a process-integrated solution in your production
    • short set-up times
    • variable lens diameters - adapted to your requirements
    • integrated UV-dryer ensures abrasion-resistant ink application
    • and many more

    Fields of application

    • Stray light minimisation
    • Reflex avoidance
    • False light suppression
    • Traceability
    • Contrast enhancement
    • Signal-to-noise ratio


    • Optic manufacturer
    • Sensor technology
    • Camera manufacturer

    We have achieved this

    • Oursystem is a fully functional semi-automatic prototype.
    • Series models are configured according to customer requirements, for example with several print heads, additional drying and similar
    • Protection of utility models was granted by the German Patent Office on April 17, 2017.
    • Climate tests are commissioned
    • Transmission and reflection measurements are commissioned
    • Additional axes and print heads are currently being constructed
    • Possibilities of a UV solution are currently being investigated
    • We are looking forward to your requirements and your feedback!
    More information can be found here › https://www.mwib.de/news/2016/randschwaerzen-und-kennzeichnen-auf-optiken/

    State of the art - Status Quo

    There is a strong desire to automate the edge-blackening of optical components.

    However, state of the art is the manual application of quick-drying liquid lacquers, mostly based on ethanol, with a brush or ink-writer.

    The lenses are mounted on a rotating table with vacuum suction or plug-in chuck.

    A considerable disadvantage is that an increasing variety of shapes and decreasing production lot sizes stand in the way of a high degree of automation.

    This is made more difficult by the use of a large number of coatings, whose property spectra vary greatly due to the different chemical bases.

    At the Fraunhofer IOF in Jena, several experiments for the automated application of edge-blackening for this process have been developed and tested for possible industrial applications.

    Scattered light in the optical system.

    How does stray light arise in the optical system?

    • Scattering on non-ideal surfaces
    • Reflections from optically ineffective surfaces
    • Reflection & scattering at effective optical surfaces

    How can it be avoided?

    • Use of iris plates is only possible to a limited extent due to lack of space
    • Geometry of the optically effective surfaces and radii is often at the expense of optical performance
    • Blackening of lens edges makes sense and is usually only a question of cost
    • ESF - Poster

    "Our developers work every day to open up new fields of application for the automatic system and to increase its effectiveness - also for YOUR range.

    An employee's development work is financially supported by funds from the State of Thuringia and the European Social Fund."