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This list covers optical lens designs grouped by tasks or overall type. The field of optical lens designing has many variables including the function the lens or group of lenses have to perform, the limits of optical glass because of the index of refraction and dispersion properties, and design constraints including realistic lens element center and edge thicknesses, minimum and maximum air ...
Optical glass refers to a quality of glass suitable for the manufacture of optical systems such as optical lenses, prisms or mirrors.Unlike window glass or crystal, whose formula is adapted to the desired aesthetic effect, optical glass contains additives designed to modify certain optical or mechanical properties of the glass: refractive index, dispersion, transmittance, thermal expansion and ...
Precision glass moulding: In this step the preform is directly formed into an optical glass lens. It is necessary to clean the glass preform and the mould before starting the process, but there is no polishing or post-machining required. Lens coating: An antireflection coating is applied to the finished lenses. The lenses are first cleaned, and ...
Low-dispersion glass (LD glass) is a type of glass with reduced chromatic aberration, meaning the refractive index does not change as strongly with different wavelengths of light. In other words, the light passing through the glass has a smaller spread or dispersion between its constituent colors, resulting in a reduced " rainbow effect" at ...
Optical lens design is the process of designing a lens to meet a set of performance requirements and constraints, including cost and manufacturing limitations. Parameters include surface profile types (spherical, aspheric, holographic, diffractive, etc.), as well as radius of curvature, distance to the next surface, material type and optionally tilt and decenter.
Inexpensive lenses may have deviations of form as large as several wavelengths (λ, 2λ, etc.). More typical industrial lenses would have deviations no larger than a quarter wavelength (λ/4). Precision lenses for use in applications such as lasers, interferometers, and holography have surfaces with a tenth of a wavelength (λ/10) tolerance or ...
A lens that is capable of magnifying the image on the film to at least the size of the original document. An easily replaceable light source that provides illumination without damaging the microfilm. Minimization of light effects of the room. A screen large enough to project the entire film image. An easily used loader for film rolls.
Screen printing is a printing technique where a mesh is used to transfer ink (or dye) onto a substrate, except in areas made impermeable to the ink by a blocking stencil.A blade or squeegee is moved across the screen in a "flood stroke" to fill the open mesh apertures with ink, and a reverse stroke then causes the screen to touch the substrate momentarily along a line of contact.