Print through elimination in fiber reinforced matrix composite mirrors and method of construction
AssigneeRaytheon Company
InventorP. Chris Theriault
Life of this patent
Estimating the term…
Abstract
A fiber reinforced matrix composite mirror that eliminates the problem of “print through”. A layer of small unbundled fibers in the matrix diffuses and randomize any stresses that are created by the weave pattern of the fiber reinforcement so that the coarse texture is not transferred to the optical quality surface thus eliminating “print through”. The layer can be provided in a variety of embodiments using random fibrils, a continuous fiber mat or a weave of single or finely towed continuous fibers. The fiber reinforced mirror is constructed by adding a mixture of matrix pre-cursor and fibers or fibrils to a common graphite fiber reinforced matrix construction.
Claims23
A mirror comprising:
- a fiber reinforced substrate including first fibers arranged in a coarse structural pattern;
- an optical quality surface on the substrate;
- a reflective optical coating on the optical quality surface;
- and a fiber reinforced layer between the substrate and the optical quality surface, said fiber reinforced layer including submicron diameter second fibers arranged in a fine structure that diffuses print through the coarse structural pattern from the substrate to the optical quality surface.
A mirror comprising:
- a common matrix;
- a first layer of fibers in the matrix, said fibers arranged in a coarse structural pattern characterized by a first scale factor;
- a second layer of submicron diameter fibers in the matrix over said first layer, said submicron diameter fibers arranged in a fine structure characterized by a second scale factor at least an order of magnitude less than the first scale factor;
- and
- a reflective optical coating over said second layer,
- said fine structure of the submicron diameter fibers in the second layer diffusing print through of the coarse structural pattern from the first layer to the reflective optical coating.
A mirror comprising:
- a substrate including a matrix reinforced with a plurality of fibers bundled into tows and woven into a cloth, said tows having a diameter of at least 0.5 mm;
- a layer of fibrils randomly bound in the matrix on the surface of the substrate, said fibrils having a diameter of less than 1 micron;
- and
- a reflective optical coating,
- said randomly bound fibrils diffusing print through of the fiber weave in the substrate to the reflective optical coating.
A mirror comprising:
- a carbon-carbon substrate;
- a layer of submicron diameter graphite fibrils randomly bound in the substrate's carbon matrix;
- and
- a reflective optical coating.
A mirror comprising:
- a substrate including a matrix reinforced with a plurality of first fibers bundled into tows and woven into a cloth, said tows having a diameter of at least 0.5 mm;
- an optical quality surface on the substrate;
- a reflective optical coating on the optical quality surface;
- and
- a layer of submicron diameter second fibers, formed of the same material as said first fibers, arranged in a fine structure and bound in the matrix on the surface of the substrate below the optical quality surface, said fine structure of submicron diameter fibers diffusing and randomizing stresses created by the weave pattern of the cloth to inhibit transference of the pattern to the optical quality surface.
Dependencies are inferred from the claim text.