Abstract: An electronic device may have a housing with a display. A protective display cover layer for the display may have an image transport layer formed from fibers or Anderson localization material. The image transport layer may include light absorbing material. Light absorbing material may be incorporated as an additive into a component of the image transport layer such as the binder layer of a coherent fiber bundle or the cladding of fibers in the image transport layer. The image transport layer may also be formed from fibers with a light absorbing layer formed in addition to a transparent cladding. The image transport layer may be formed from Anderson localization material that has light absorbing material. Fibers for the image transport layer may be extruded with light absorbing portions. A polymer preform having light absorbing material may be drawn to form fibers for the image transport layer.

Abstract: A proximity sensor includes a light source configured to emit a beam of optical radiation and a detector configured to output an electrical signal in response to the optical radiation that is incident on the detector. A first optical multimode fiber is configured to receive the emitted beam and to direct the emitted beam toward an object. A second optical multimode fiber is configured to receive the optical radiation reflected from the object and to convey the received optical radiation to the detector. A processor is coupled to process the electrical signal so as to compute a distance to the object.

Abstract: A system may include one or more electronic devices. Fiber bundles may be provided to convey light. A fiber bundle may have a bend along its length. Fibers for the fiber bundle may be formed from polymer cores coated with polymer claddings. The fibers may have end faces coated with antireflection coatings. The antireflection coatings may be formed from amorphous fluoropolymer deposited from solution. The fluoropolymer may be applied to the end faces of the fibers by dipping, spraying, or by dispensing with a needle dispenser or other dispensing tool. An optical component such as a light-emitting device for a communications system, an illumination system, or a sensor system may provide infrared light that is guided through the fiber bundle.

Abstract: An electronic device may have a housing with a display. A protective display cover layer for the display may have an image transport layer such as an image transport layer formed from Anderson localization material. Anderson localization material may be formed using equipment such as heated molds, extrusion equipment, fusion tools, and fiber drawing equipment. The materials used to form a block of Anderson localization material may be polymers or other transparent materials. Elevated temperatures such as temperatures above the melting points of the polymers may be used during extrusion, fusion, drawing, and other operations.

Abstract: An electronic device may have a display, a display cover layer, and a drawn sheet-packed coherent fiber bundle. The coherent fiber bundle may have an input surface that receives an image from the display and a corresponding output surface to which the image is transported. The coherent fiber bundle may be placed between the display and the display cover layer and mounted to a housing. The coherent fiber bundle may have fiber cores with bends that help conceal the housing from view and make the display appear borderless. The coherent fiber bundle has filaments formed from elongated strands of binder in which multiple fibers are embedded. Sheets of filaments are stacked and fused together to form a block of material that is subsequently drawn to form the drawn sheet-packed coherent fiber bundle.

Abstract: A light pipe such as a fiber ribbon may be formed from fibers joined by binder such as extruded binder. The fiber ribbon or other light pipe may have bends. A light source may provide light to an input of a fiber ribbon that is guided by the fiber ribbon to a corresponding output. The output may be located in an interior portion of an electronic device or may be positioned so that light from the output exits the electronic device and illuminates external objects. The light source may have light-emitting devices on a substrate. The light-emitting devices may be vertical cavity surface-emitting laser diodes or other lasers and/or may be light-emitting diodes. Light-emitting devices may be arranged in discrete clusters corresponding to the locations of fiber cores in the fiber ribbon.

Abstract: In a method of making a material, a bismaleimide system is heated to generate a bismaleimide liquid (110). The bismaleimide liquid is degassed (114) to generate a degassed bismaleimide liquid. At least one of high speed shear mixing and probe sonication is performed to the degassed bismaleimide liquid to generate a highly mixed bismaleimide liquid phase (112). The highly mixed bismaleimide liquid phase is cured (116). A bismaleimide product is made by heating a three component bismaleimide system to generate a bismaleimide liquid, which is degassed in a 30 mbar vacuum until no new visually perceptible bubbles are detected. The degassed liquid is high speed shear mixed at a speed of 3500 RPM for 10 minutes to generate a highly mixed bismaleimide liquid phase, which is cured to make the bismaleimide product. A substance includes cured bismaleimide having an impact strength in a range of 56 kJ/m2 to 82 kJ/m2.

Abstract: An electronic device may have a housing with a display. A protective display cover layer for the display may have an image transport layer such as a fiber optic plate. The fiber optic plate may be formed from fibers. An extruder may form fiber bundles that each include a respective plurality of fibers distributed in binder material. The fiber bundles from the extruder may be fed directly to a block forming die. The block forming die may receive the fiber bundles from the extruder and output a unitary fiber block. The fiber bundles may remain heated in the block forming die such that the binder material of the fiber bundles seamlessly merges during formation of the unitary fiber block. A cutter can be used to cut off a layer of the unitary fiber block. This layer may be machined and polished to form the fiber optic plate.

Abstract: An electronic device may have a housing with a display. A protective display cover layer for the display may have an image transport layer such as an image transport layer formed from optical fibers. Extruded filaments of binder material may be fused together to form a layer of binder for the image transport layer. Each filament may contain multiple embedded optical fibers. As a result of the extrusion process, the optical fibers may be characterized by increasing lateral deformation at increasing distances from the center of the filament in which the optical fibers are embedded. Tension variations and variations in the orientation angle of the fibers in the image transport layer can be maintained below desired limits to ensure satisfactory optical performance for the image transport layer. The optical fibers and binder may be formed from polymers or other clear materials.

Abstract: A method of making a HIPP composite comprising blending polypropylene-coated functionalized multiwall carbon nanotubes (PP/f-MWNT) with a first PP to produce a PP and PP/f-MWNT mixture, wherein PP/f-MWNT comprise f-MWNT coated with a second PP via non-covalent interactions, wherein PP and PP/f-MWNT mixture comprises 0.0005 to 5 wt. % f-MWNT, based on the weight of PP and PP/f-MWNT mixture, wherein the first PP and the second PP are the same or different; melt blending the PP and PP/f-MWNT mixture to form a molten PP and PP/f-MWNT mixture; and shaping the molten PP and PP/f-MWNT mixture to form the HIPP composite. A HIPP composite comprising a continuous polymeric phase having dispersed therein a plurality of PP/f-MWNT, wherein the continuous polymeric phase comprises a first PP, wherein PP/f-MWNT comprise f-MWNT coated with a second PP via non-covalent interactions, wherein HIPP composite comprises 0.0005 to 5 wt. % f-MWNT, based on the weight of HIPP.