FIELD

This relates generally to electronic devices, and, more particularly, to electronic devices with displays.

BACKGROUND

Electronic devices may have displays. Displays have arrays of pixels for displaying images for a user. The shape of many displays can pose challenges during integration into an electronic device, particularly in situations where space is limited.

SUMMARY

An electronic device may have a housing with a display. The display may be overlapped by an image transport layer such as a coherent fiber bundle or layer of Anderson localization material. In some configurations, fibers in an image transport layer may be joined using Anderson localization material that serves as binder.

The image transport layer may have an input surface that receives an image from the display and a corresponding output surface to which the image is transported. The input surface and output surface may have different shapes. During fabrication of the image transport layer, molding techniques, grinding and polishing techniques, and other processes may be used to deform the image transport layer and therefore deform the shape of the output surface. For example, the periphery of the image transport layer may be stretched laterally outwards and provided with a cross-sectional profile that curves downwards at increasing distances from the center of the image transport layer. These operations may expand the area of the output surface in the periphery of the image transport layer relative to the area at the center of the image transport layer.

Optical uniformity across the output surface of an image transport layer can be enhanced by enhancing uniformity in fiber core diameters and other attributes across the output surface. With an illustrative configuration, the process of deforming the undeformed image transport layer primarily or exclusively expands a binder fraction associated with the fibers and does not impact fiber diameters. In another illustrative configuration, an undeformed block of image transport layer material is preconfigured so that when processed and deformed to form a final desired image transport layer shape, one or more attributes of the image transport layer are uniform across the output surface.

As an example, an undeformed image transport layer can be formed that has smaller fiber cores, thinner fiber claddings, and/or a smaller binder fraction near the periphery of the layer than in the center of the layer. When deformed by heat and pressure during molding and/or during grinding and polishing, the area of the output surface in the periphery expands. This increases fiber core diameters, fiber cladding thickness, and/or binder fraction. By configuring the variation of the attributes of the fibers and binder as a function of lateral position in an undeformed image transport layer, the resulting deformed image transport layer will have fiber and binder attributes that vary less across the output surface than in the undeformed image transport layer or that are uniform across the output surface.

