Electronic devices with curved display surfaces
An electronic device may have a display mounted in a housing. The display may have a pixel array that produces images. A display cover layer may overlap the pixel array. The display cover layer may have a planar central area surrounded by a peripheral edge area with a curved cross-sectional profile. From an on-axis viewing angle, an image on the pixel array is fully viewable through the planar central area and the peripheral edge area. From an off-axis viewing angle, the image is partly viewable through the peripheral edge area and not through the central area. To avoid an undesired color cast in the partly viewable image seen through the peripheral edge area of the display cover layer, the display may be provided with color cast compensation structures such as a guest-host liquid crystal layer that exhibits an anisotropic colored light absorption characteristic, a diffuser layer, and/or other optical structures.
1 . An electronic device comprising:
a housing;
a pixel array configured to produce an image;
a display cover layer that is coupled to the housing and overlaps the pixel array, the display cover layer having a peripheral edge with a curved cross-sectional profile;
a color cast compensation layer between the pixel array and the display cover layer and configured to alter a color cast in an image portion viewable through the peripheral edge with the curved cross-sectional profile; and
a layer of adhesive that attaches the display cover layer to a circular polarizer, wherein the color cast compensation layer forms a part of the circular polarizer and wherein the part of the circular polarizer formed by the color cast compensation layer is configured to preferentially absorb light associated with the color cast as a function of increasing angle relative to a surface normal of the pixel array.
2 . The electronic device defined in claim 1 , wherein the layer of adhesive is configured to form a light diffusing layer.
3 . The electronic device defined in claim 1 , wherein the part of the circular polarizer formed by the color cast compensation layer is configured to exhibit a first level of light transmission for light associated with the color cast at a first angle relative to the surface normal of the pixel array and exhibit a second level of light transmission for light associated with the color cast at a second angle relative to the surface normal of the pixel array, wherein the second angle is greater than the first angle, and wherein the second level of light transmission is less than the first level of light transmission.
4 . The electronic device defined in claim 1 , wherein the color cast comprises a yellow color cast and wherein the part of the circular polarizer formed by the color cast compensation layer is configured to reduce the yellow color cast in the image portion by absorbing yellow off-axis light more than off-axis light of non-yellow colors.
5 . The electronic device defined in claim 4 , wherein the part of the circular polarizer formed by the color cast compensation layer is configured to absorb the yellow off-axis light more than yellow on-axis light, wherein the yellow on-axis light is at a first angle relative to the surface normal of the pixel array, wherein the yellow off-axis light is at a second angle relative to the surface normal of the pixel array, and wherein the second angle is greater than the first angle.
6 . The electronic device defined in claim 1 , wherein the part of the circular polarizer formed by the color cast compensation layer comprises a guest-host liquid crystal layer.
7 . The electronic device defined in claim 6 , wherein the guest-host liquid crystal layer of the part of the circular polarizer formed by the color cast compensation layer comprises a light-absorbing dye.
8 . The electronic device defined in claim 7 , wherein the color cast comprises a yellow color cast and wherein the light-absorbing dye in the guest-host liquid crystal layer of the part of the circular polarizer formed by the color cast compensation layer comprises yellow-light-absorbing dye.
9 . The electronic device defined in claim 1 further comprising:
a light diffusing layer configured to alter the color cast in the image portion viewable through the peripheral edge with the curved cross-sectional profile.
10 . The electronic device defined in claim 1 , wherein the color cast comprises a yellow color cast, the electronic device further comprising an antireflection layer between the pixel array and the display cover layer that is configured to reduce reflections of yellow light relative to non-yellow light.
11 . The electronic device defined in claim 1 , wherein the color cast comprises a yellow color cast, the electronic device further comprising an optically transparent layer between the display cover layer and the pixel array that is configured to direct off-axis light away from the peripheral edge with the curved cross-sectional profile.
12 . An electronic device comprising:
a housing;
a pixel array;
a display cover layer that is coupled to the housing and overlaps the pixel array, the display cover layer having a peripheral edge with a curved cross-sectional profile;
a light diffusing layer between a guest-host liquid crystal layer, configured to preferentially absorb light associated with a color cast as a function of increasing angle relative to a surface normal of the pixel array, and the display cover layer; and
a linear polarizer between the light diffusing layer and the guest-host liquid crystal layer configured to preferentially absorb the light associated with the color cast as the function of increasing angle relative to the surface normal of the pixel array.
13 . The electronic device defined in claim 12 , wherein the guest-host liquid crystal layer comprises a light-absorbing dye.
14 . The electronic device defined in claim 13 , wherein the guest-host liquid crystal layer comprises polymer layers and a layer of liquid crystal material between the polymer layers and wherein the layer of liquid crystal material contains the light-absorbing dye.
15 . The electronic device defined in claim 12 further comprising:
an adhesive layer between the light diffusing layer and the display cover layer.
16 . The electronic device defined in claim 12 , wherein the linear polarizer and the guest-host liquid crystal layer form a circular polarizer that overlaps the pixel array and wherein the light diffusing layer comprises a layer of adhesive containing embedded light-scattering particles that is interposed between the display cover layer and the circular polarizer.
17 . The electronic device defined in claim 12 , wherein the light diffusing layer comprises a layer of adhesive that attaches the display cover layer to the linear polarizer.
18 . The electronic device defined in claim 12 further comprising:
a layer of adhesive that attaches the display cover layer to the light diffusing layer.
19 . An electronic device comprising:
a housing;
a pixel array configured to produce an image;
a display cover layer that overlaps the pixel array, wherein the display cover layer has a peripheral edge with a curved cross-sectional profile;
an optically transparent layer between the display cover layer and the pixel array and configured to shunt off-axis light associated with a color cast of the image away from the peripheral edge with the curved cross-sectional profile and into a band below the peripheral edge with the curved cross-sectional profile; and
an antireflection layer between the display cover layer and the pixel array and configured to exhibit wavelength-dependent light transmission by passing more light of a first wavelength than light of a second wavelength and by reflecting more light of the second wavelength than light of the first wavelength, wherein the antireflection layer is configured to receive additional off-axis light of the first wavelength emitted by the pixel array and reflected back at an outer surface of the display cover layer and is configured to pass the additional off-axis light of the first wavelength after being reflected back at the outer surface of the display cover layer toward the pixel array.
20 . The electronic device defined in claim 19 , wherein the off-axis light associated with the color cast of the image comprises yellow off-axis light and wherein the optically transparent layer is configured to reflect the yellow off-axis light at an interface between the optically transparent layer and the display cover layer.